* [PATCH v6 00/31] kmemcg shrinkers
@ 2013-05-12 18:13 ` Glauber Costa
0 siblings, 0 replies; 151+ messages in thread
From: Glauber Costa @ 2013-05-12 18:13 UTC (permalink / raw)
To: linux-mm
Cc: cgroups, Andrew Morton, Greg Thelen, kamezawa.hiroyu,
Michal Hocko, Johannes Weiner, linux-fsdevel, Dave Chinner
Initial notes:
==============
Mel, Dave, this is the last round of fixes I have for the series. The fixes are
few, and I was mostly interested in getting this out based on an up2date tree
so Dave can verify it. This should apply fine ontop of Friday's linux-next.
Alternatively, please grab from branch "kmemcg-lru-shrinker" at:
git://git.kernel.org/pub/scm/linux/kernel/git/glommer/memcg.git
Main changes from *v5:
* Rebased to linux-next, and fix the conflicts with the dcache.
* Make sure LRU_RETRY only retry once
* Prevent the bcache shrinker to scan the caches when disabled (by returning
0 in the count function)
* Fix i915 return code when mutex cannot be acquired.
* Only scan less-than-batch objects in memcg scenarios
Hi,
This patchset implements targeted shrinking for memcg when kmem limits are
present. So far, we've been accounting kernel objects but failing allocations
when short of memory. This is because our only option would be to call the
global shrinker, depleting objects from all caches and breaking isolation.
The main idea is to associate per-memcg lists with each of the LRUs. The main
LRU still provides a single entry point and when adding or removing an element
from the LRU, we use the page information to figure out which memcg it belongs
to and relay it to the right list.
Base work:
==========
Please note that this builds upon the recent work from Dave Chinner that
sanitizes the LRU shrinking API and make the shrinkers node aware. Node
awareness is not *strictly* needed for my work, but I still perceive it
as an advantage. The API unification is a major need, and I build upon it
heavily. That allows us to manipulate the LRUs without knowledge of the
underlying objects with ease. This time, I am including that work here as
a baseline.
Main changes from *v5:
* Rebased to linux-next, and fix the conflicts with the dcache.
* Make sure LRU_RETRY only retry once
* Prevent the bcache shrinker to scan the caches when disabled (by returning
0 in the count function)
* Fix i915 return code when mutex cannot be acquired.
* Only scan less-than-batch objects in memcg scenarios
Main changes from *v4:
* Fixed a bug in user-generated memcg pressure
* Fixed overly-agressive slab shrinker behavior spotted by Mel Gorman
* Various other fixes and comments by Mel Gorman
Main changes from *v3:
* Merged suggestions from mailing list.
* Removed the memcg-walking code from LRU. vmscan now drives all the hierarchy
decisions, which makes more sense
* lazily free the old memcg arrays (needs now to be saved in struct lru). Since
we need to call synchronize_rcu, calling it for every LRU can become expensive
* Moved the dead memcg shrinker to vmpressure. Already independently sent to
linux-mm for review.
* Changed locking convention for LRU_RETRY. It now needs to return locked, which
silents warnings about possible lock unbalance (although previous code was
correct)
Main changes from *v2:
* shrink dead memcgs when global pressure kicks in. Uses the new lru API.
* bugfixes and comments from the mailing list.
* proper hierarchy-aware walk in shrink_slab.
Main changes from *v1:
* merged comments from the mailing list
* reworked lru-memcg API
* effective proportional shrinking
* sanitized locking on the memcg side
* bill user memory first when kmem == umem
* various bugfixes
Dave Chinner (17):
dcache: convert dentry_stat.nr_unused to per-cpu counters
dentry: move to per-sb LRU locks
dcache: remove dentries from LRU before putting on dispose list
mm: new shrinker API
shrinker: convert superblock shrinkers to new API
list: add a new LRU list type
inode: convert inode lru list to generic lru list code.
dcache: convert to use new lru list infrastructure
list_lru: per-node list infrastructure
shrinker: add node awareness
fs: convert inode and dentry shrinking to be node aware
xfs: convert buftarg LRU to generic code
xfs: convert dquot cache lru to list_lru
fs: convert fs shrinkers to new scan/count API
drivers: convert shrinkers to new count/scan API
shrinker: convert remaining shrinkers to count/scan API
shrinker: Kill old ->shrink API.
Glauber Costa (14):
super: fix calculation of shrinkable objects for small numbers
i915: bail out earlier when shrinker cannot acquire mutex
hugepage: convert huge zero page shrinker to new shrinker API
vmscan: also shrink slab in memcg pressure
memcg,list_lru: duplicate LRUs upon kmemcg creation
lru: add an element to a memcg list
list_lru: per-memcg walks
memcg: per-memcg kmem shrinking
memcg: scan cache objects hierarchically
vmscan: take at least one pass with shrinkers
super: targeted memcg reclaim
memcg: move initialization to memcg creation
vmpressure: in-kernel notifications
memcg: reap dead memcgs upon global memory pressure.
arch/x86/kvm/mmu.c | 28 +-
drivers/gpu/drm/i915/i915_dma.c | 4 +-
drivers/gpu/drm/i915/i915_gem.c | 71 +++--
drivers/gpu/drm/ttm/ttm_page_alloc.c | 48 ++--
drivers/gpu/drm/ttm/ttm_page_alloc_dma.c | 55 ++--
drivers/md/bcache/btree.c | 43 +--
drivers/md/bcache/sysfs.c | 2 +-
drivers/md/dm-bufio.c | 65 +++--
drivers/staging/android/ashmem.c | 46 +++-
drivers/staging/android/lowmemorykiller.c | 40 +--
drivers/staging/zcache/zcache-main.c | 29 +-
fs/dcache.c | 240 ++++++++++-------
fs/drop_caches.c | 1 +
fs/ext4/extents_status.c | 30 ++-
fs/gfs2/glock.c | 30 ++-
fs/gfs2/main.c | 3 +-
fs/gfs2/quota.c | 14 +-
fs/gfs2/quota.h | 4 +-
fs/inode.c | 175 +++++-------
fs/internal.h | 5 +
fs/mbcache.c | 53 ++--
fs/nfs/dir.c | 20 +-
fs/nfs/internal.h | 4 +-
fs/nfs/super.c | 3 +-
fs/nfsd/nfscache.c | 31 ++-
fs/quota/dquot.c | 39 ++-
fs/super.c | 107 +++++---
fs/ubifs/shrinker.c | 20 +-
fs/ubifs/super.c | 3 +-
fs/ubifs/ubifs.h | 3 +-
fs/xfs/xfs_buf.c | 169 ++++++------
fs/xfs/xfs_buf.h | 5 +-
fs/xfs/xfs_dquot.c | 7 +-
fs/xfs/xfs_icache.c | 4 +-
fs/xfs/xfs_icache.h | 2 +-
fs/xfs/xfs_qm.c | 275 +++++++++----------
fs/xfs/xfs_qm.h | 4 +-
fs/xfs/xfs_super.c | 12 +-
include/linux/dcache.h | 4 +
include/linux/fs.h | 25 +-
include/linux/list_lru.h | 145 ++++++++++
include/linux/memcontrol.h | 45 ++++
include/linux/shrinker.h | 44 ++-
include/linux/swap.h | 2 +
include/linux/vmpressure.h | 6 +
include/trace/events/vmscan.h | 4 +-
lib/Makefile | 2 +-
lib/list_lru.c | 433 ++++++++++++++++++++++++++++++
mm/huge_memory.c | 17 +-
mm/memcontrol.c | 430 +++++++++++++++++++++++++----
mm/memory-failure.c | 2 +
mm/slab_common.c | 1 -
mm/vmpressure.c | 52 +++-
mm/vmscan.c | 325 +++++++++++++++-------
net/sunrpc/auth.c | 45 +++-
55 files changed, 2339 insertions(+), 937 deletions(-)
create mode 100644 include/linux/list_lru.h
create mode 100644 lib/list_lru.c
--
1.8.1.4
^ permalink raw reply [flat|nested] 151+ messages in thread
* [PATCH v6 00/31] kmemcg shrinkers
@ 2013-05-12 18:13 ` Glauber Costa
0 siblings, 0 replies; 151+ messages in thread
From: Glauber Costa @ 2013-05-12 18:13 UTC (permalink / raw)
To: linux-mm
Cc: cgroups, Andrew Morton, Greg Thelen, kamezawa.hiroyu,
Michal Hocko, Johannes Weiner, linux-fsdevel, Dave Chinner
Initial notes:
==============
Mel, Dave, this is the last round of fixes I have for the series. The fixes are
few, and I was mostly interested in getting this out based on an up2date tree
so Dave can verify it. This should apply fine ontop of Friday's linux-next.
Alternatively, please grab from branch "kmemcg-lru-shrinker" at:
git://git.kernel.org/pub/scm/linux/kernel/git/glommer/memcg.git
Main changes from *v5:
* Rebased to linux-next, and fix the conflicts with the dcache.
* Make sure LRU_RETRY only retry once
* Prevent the bcache shrinker to scan the caches when disabled (by returning
0 in the count function)
* Fix i915 return code when mutex cannot be acquired.
* Only scan less-than-batch objects in memcg scenarios
Hi,
This patchset implements targeted shrinking for memcg when kmem limits are
present. So far, we've been accounting kernel objects but failing allocations
when short of memory. This is because our only option would be to call the
global shrinker, depleting objects from all caches and breaking isolation.
The main idea is to associate per-memcg lists with each of the LRUs. The main
LRU still provides a single entry point and when adding or removing an element
from the LRU, we use the page information to figure out which memcg it belongs
to and relay it to the right list.
Base work:
==========
Please note that this builds upon the recent work from Dave Chinner that
sanitizes the LRU shrinking API and make the shrinkers node aware. Node
awareness is not *strictly* needed for my work, but I still perceive it
as an advantage. The API unification is a major need, and I build upon it
heavily. That allows us to manipulate the LRUs without knowledge of the
underlying objects with ease. This time, I am including that work here as
a baseline.
Main changes from *v5:
* Rebased to linux-next, and fix the conflicts with the dcache.
* Make sure LRU_RETRY only retry once
* Prevent the bcache shrinker to scan the caches when disabled (by returning
0 in the count function)
* Fix i915 return code when mutex cannot be acquired.
* Only scan less-than-batch objects in memcg scenarios
Main changes from *v4:
* Fixed a bug in user-generated memcg pressure
* Fixed overly-agressive slab shrinker behavior spotted by Mel Gorman
* Various other fixes and comments by Mel Gorman
Main changes from *v3:
* Merged suggestions from mailing list.
* Removed the memcg-walking code from LRU. vmscan now drives all the hierarchy
decisions, which makes more sense
* lazily free the old memcg arrays (needs now to be saved in struct lru). Since
we need to call synchronize_rcu, calling it for every LRU can become expensive
* Moved the dead memcg shrinker to vmpressure. Already independently sent to
linux-mm for review.
* Changed locking convention for LRU_RETRY. It now needs to return locked, which
silents warnings about possible lock unbalance (although previous code was
correct)
Main changes from *v2:
* shrink dead memcgs when global pressure kicks in. Uses the new lru API.
* bugfixes and comments from the mailing list.
* proper hierarchy-aware walk in shrink_slab.
Main changes from *v1:
* merged comments from the mailing list
* reworked lru-memcg API
* effective proportional shrinking
* sanitized locking on the memcg side
* bill user memory first when kmem == umem
* various bugfixes
Dave Chinner (17):
dcache: convert dentry_stat.nr_unused to per-cpu counters
dentry: move to per-sb LRU locks
dcache: remove dentries from LRU before putting on dispose list
mm: new shrinker API
shrinker: convert superblock shrinkers to new API
list: add a new LRU list type
inode: convert inode lru list to generic lru list code.
dcache: convert to use new lru list infrastructure
list_lru: per-node list infrastructure
shrinker: add node awareness
fs: convert inode and dentry shrinking to be node aware
xfs: convert buftarg LRU to generic code
xfs: convert dquot cache lru to list_lru
fs: convert fs shrinkers to new scan/count API
drivers: convert shrinkers to new count/scan API
shrinker: convert remaining shrinkers to count/scan API
shrinker: Kill old ->shrink API.
Glauber Costa (14):
super: fix calculation of shrinkable objects for small numbers
i915: bail out earlier when shrinker cannot acquire mutex
hugepage: convert huge zero page shrinker to new shrinker API
vmscan: also shrink slab in memcg pressure
memcg,list_lru: duplicate LRUs upon kmemcg creation
lru: add an element to a memcg list
list_lru: per-memcg walks
memcg: per-memcg kmem shrinking
memcg: scan cache objects hierarchically
vmscan: take at least one pass with shrinkers
super: targeted memcg reclaim
memcg: move initialization to memcg creation
vmpressure: in-kernel notifications
memcg: reap dead memcgs upon global memory pressure.
arch/x86/kvm/mmu.c | 28 +-
drivers/gpu/drm/i915/i915_dma.c | 4 +-
drivers/gpu/drm/i915/i915_gem.c | 71 +++--
drivers/gpu/drm/ttm/ttm_page_alloc.c | 48 ++--
drivers/gpu/drm/ttm/ttm_page_alloc_dma.c | 55 ++--
drivers/md/bcache/btree.c | 43 +--
drivers/md/bcache/sysfs.c | 2 +-
drivers/md/dm-bufio.c | 65 +++--
drivers/staging/android/ashmem.c | 46 +++-
drivers/staging/android/lowmemorykiller.c | 40 +--
drivers/staging/zcache/zcache-main.c | 29 +-
fs/dcache.c | 240 ++++++++++-------
fs/drop_caches.c | 1 +
fs/ext4/extents_status.c | 30 ++-
fs/gfs2/glock.c | 30 ++-
fs/gfs2/main.c | 3 +-
fs/gfs2/quota.c | 14 +-
fs/gfs2/quota.h | 4 +-
fs/inode.c | 175 +++++-------
fs/internal.h | 5 +
fs/mbcache.c | 53 ++--
fs/nfs/dir.c | 20 +-
fs/nfs/internal.h | 4 +-
fs/nfs/super.c | 3 +-
fs/nfsd/nfscache.c | 31 ++-
fs/quota/dquot.c | 39 ++-
fs/super.c | 107 +++++---
fs/ubifs/shrinker.c | 20 +-
fs/ubifs/super.c | 3 +-
fs/ubifs/ubifs.h | 3 +-
fs/xfs/xfs_buf.c | 169 ++++++------
fs/xfs/xfs_buf.h | 5 +-
fs/xfs/xfs_dquot.c | 7 +-
fs/xfs/xfs_icache.c | 4 +-
fs/xfs/xfs_icache.h | 2 +-
fs/xfs/xfs_qm.c | 275 +++++++++----------
fs/xfs/xfs_qm.h | 4 +-
fs/xfs/xfs_super.c | 12 +-
include/linux/dcache.h | 4 +
include/linux/fs.h | 25 +-
include/linux/list_lru.h | 145 ++++++++++
include/linux/memcontrol.h | 45 ++++
include/linux/shrinker.h | 44 ++-
include/linux/swap.h | 2 +
include/linux/vmpressure.h | 6 +
include/trace/events/vmscan.h | 4 +-
lib/Makefile | 2 +-
lib/list_lru.c | 433 ++++++++++++++++++++++++++++++
mm/huge_memory.c | 17 +-
mm/memcontrol.c | 430 +++++++++++++++++++++++++----
mm/memory-failure.c | 2 +
mm/slab_common.c | 1 -
mm/vmpressure.c | 52 +++-
mm/vmscan.c | 325 +++++++++++++++-------
net/sunrpc/auth.c | 45 +++-
55 files changed, 2339 insertions(+), 937 deletions(-)
create mode 100644 include/linux/list_lru.h
create mode 100644 lib/list_lru.c
--
1.8.1.4
--
To unsubscribe, send a message with 'unsubscribe linux-mm' in
the body to majordomo@kvack.org. For more info on Linux MM,
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^ permalink raw reply [flat|nested] 151+ messages in thread
* [PATCH v6 01/31] super: fix calculation of shrinkable objects for small numbers
2013-05-12 18:13 ` Glauber Costa
@ 2013-05-12 18:13 ` Glauber Costa
-1 siblings, 0 replies; 151+ messages in thread
From: Glauber Costa @ 2013-05-12 18:13 UTC (permalink / raw)
To: linux-mm
Cc: cgroups, Andrew Morton, Greg Thelen, kamezawa.hiroyu,
Michal Hocko, Johannes Weiner, linux-fsdevel, Dave Chinner,
Glauber Costa, Theodore Ts'o, Al Viro
The sysctl knob sysctl_vfs_cache_pressure is used to determine which
percentage of the shrinkable objects in our cache we should actively try
to shrink.
It works great in situations in which we have many objects (at least
more than 100), because the aproximation errors will be negligible. But
if this is not the case, specially when total_objects < 100, we may end
up concluding that we have no objects at all (total / 100 = 0, if total
< 100).
This is certainly not the biggest killer in the world, but may matter in
very low kernel memory situations.
[ v2: fix it for all occurrences of sysctl_vfs_cache_pressure ]
Signed-off-by: Glauber Costa <glommer@openvz.org>
Reviewed-by: Carlos Maiolino <cmaiolino@redhat.com>
Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Acked-by: Mel Gorman <mgorman@suse.de>
CC: Dave Chinner <david@fromorbit.com>
CC: "Theodore Ts'o" <tytso@mit.edu>
CC: Al Viro <viro@zeniv.linux.org.uk>
---
fs/gfs2/glock.c | 2 +-
fs/gfs2/quota.c | 2 +-
fs/mbcache.c | 2 +-
fs/nfs/dir.c | 2 +-
fs/quota/dquot.c | 5 ++---
fs/super.c | 14 +++++++-------
fs/xfs/xfs_qm.c | 2 +-
include/linux/dcache.h | 4 ++++
8 files changed, 18 insertions(+), 15 deletions(-)
diff --git a/fs/gfs2/glock.c b/fs/gfs2/glock.c
index 9435384..3bd2748 100644
--- a/fs/gfs2/glock.c
+++ b/fs/gfs2/glock.c
@@ -1463,7 +1463,7 @@ static int gfs2_shrink_glock_memory(struct shrinker *shrink,
gfs2_scan_glock_lru(sc->nr_to_scan);
}
- return (atomic_read(&lru_count) / 100) * sysctl_vfs_cache_pressure;
+ return vfs_pressure_ratio(atomic_read(&lru_count));
}
static struct shrinker glock_shrinker = {
diff --git a/fs/gfs2/quota.c b/fs/gfs2/quota.c
index c7c840e..5c14206 100644
--- a/fs/gfs2/quota.c
+++ b/fs/gfs2/quota.c
@@ -114,7 +114,7 @@ int gfs2_shrink_qd_memory(struct shrinker *shrink, struct shrink_control *sc)
spin_unlock(&qd_lru_lock);
out:
- return (atomic_read(&qd_lru_count) * sysctl_vfs_cache_pressure) / 100;
+ return vfs_pressure_ratio(atomic_read(&qd_lru_count));
}
static u64 qd2index(struct gfs2_quota_data *qd)
diff --git a/fs/mbcache.c b/fs/mbcache.c
index 8c32ef3..5eb0476 100644
--- a/fs/mbcache.c
+++ b/fs/mbcache.c
@@ -189,7 +189,7 @@ mb_cache_shrink_fn(struct shrinker *shrink, struct shrink_control *sc)
list_for_each_entry_safe(entry, tmp, &free_list, e_lru_list) {
__mb_cache_entry_forget(entry, gfp_mask);
}
- return (count / 100) * sysctl_vfs_cache_pressure;
+ return vfs_pressure_ratio(count);
}
diff --git a/fs/nfs/dir.c b/fs/nfs/dir.c
index e093e73..54d7c47 100644
--- a/fs/nfs/dir.c
+++ b/fs/nfs/dir.c
@@ -1998,7 +1998,7 @@ remove_lru_entry:
}
spin_unlock(&nfs_access_lru_lock);
nfs_access_free_list(&head);
- return (atomic_long_read(&nfs_access_nr_entries) / 100) * sysctl_vfs_cache_pressure;
+ return vfs_pressure_ratio(atomic_long_read(&nfs_access_nr_entries));
}
static void __nfs_access_zap_cache(struct nfs_inode *nfsi, struct list_head *head)
diff --git a/fs/quota/dquot.c b/fs/quota/dquot.c
index 3e64169..762b09c 100644
--- a/fs/quota/dquot.c
+++ b/fs/quota/dquot.c
@@ -719,9 +719,8 @@ static int shrink_dqcache_memory(struct shrinker *shrink,
prune_dqcache(nr);
spin_unlock(&dq_list_lock);
}
- return ((unsigned)
- percpu_counter_read_positive(&dqstats.counter[DQST_FREE_DQUOTS])
- /100) * sysctl_vfs_cache_pressure;
+ return vfs_pressure_ratio(
+ percpu_counter_read_positive(&dqstats.counter[DQST_FREE_DQUOTS]));
}
static struct shrinker dqcache_shrinker = {
diff --git a/fs/super.c b/fs/super.c
index 7465d43..2a37fd6 100644
--- a/fs/super.c
+++ b/fs/super.c
@@ -82,13 +82,13 @@ static int prune_super(struct shrinker *shrink, struct shrink_control *sc)
int inodes;
/* proportion the scan between the caches */
- dentries = (sc->nr_to_scan * sb->s_nr_dentry_unused) /
- total_objects;
- inodes = (sc->nr_to_scan * sb->s_nr_inodes_unused) /
- total_objects;
+ dentries = mult_frac(sc->nr_to_scan, sb->s_nr_dentry_unused,
+ total_objects);
+ inodes = mult_frac(sc->nr_to_scan, sb->s_nr_inodes_unused,
+ total_objects);
if (fs_objects)
- fs_objects = (sc->nr_to_scan * fs_objects) /
- total_objects;
+ fs_objects = mult_frac(sc->nr_to_scan, fs_objects,
+ total_objects);
/*
* prune the dcache first as the icache is pinned by it, then
* prune the icache, followed by the filesystem specific caches
@@ -104,7 +104,7 @@ static int prune_super(struct shrinker *shrink, struct shrink_control *sc)
sb->s_nr_inodes_unused + fs_objects;
}
- total_objects = (total_objects / 100) * sysctl_vfs_cache_pressure;
+ total_objects = vfs_pressure_ratio(total_objects);
drop_super(sb);
return total_objects;
}
diff --git a/fs/xfs/xfs_qm.c b/fs/xfs/xfs_qm.c
index f41702b..7ade175 100644
--- a/fs/xfs/xfs_qm.c
+++ b/fs/xfs/xfs_qm.c
@@ -1585,7 +1585,7 @@ xfs_qm_shake(
}
out:
- return (qi->qi_lru_count / 100) * sysctl_vfs_cache_pressure;
+ return vfs_pressure_ratio(qi->qi_lru_count);
}
/*
diff --git a/include/linux/dcache.h b/include/linux/dcache.h
index 1a6bb81..4d24a12 100644
--- a/include/linux/dcache.h
+++ b/include/linux/dcache.h
@@ -411,4 +411,8 @@ static inline bool d_mountpoint(struct dentry *dentry)
extern int sysctl_vfs_cache_pressure;
+static inline unsigned long vfs_pressure_ratio(unsigned long val)
+{
+ return mult_frac(val, sysctl_vfs_cache_pressure, 100);
+}
#endif /* __LINUX_DCACHE_H */
--
1.8.1.4
--
To unsubscribe, send a message with 'unsubscribe linux-mm' in
the body to majordomo@kvack.org. For more info on Linux MM,
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^ permalink raw reply related [flat|nested] 151+ messages in thread* [PATCH v6 01/31] super: fix calculation of shrinkable objects for small numbers
@ 2013-05-12 18:13 ` Glauber Costa
0 siblings, 0 replies; 151+ messages in thread
From: Glauber Costa @ 2013-05-12 18:13 UTC (permalink / raw)
To: linux-mm
Cc: cgroups, Andrew Morton, Greg Thelen, kamezawa.hiroyu,
Michal Hocko, Johannes Weiner, linux-fsdevel, Dave Chinner,
Glauber Costa, Theodore Ts'o, Al Viro
The sysctl knob sysctl_vfs_cache_pressure is used to determine which
percentage of the shrinkable objects in our cache we should actively try
to shrink.
It works great in situations in which we have many objects (at least
more than 100), because the aproximation errors will be negligible. But
if this is not the case, specially when total_objects < 100, we may end
up concluding that we have no objects at all (total / 100 = 0, if total
< 100).
This is certainly not the biggest killer in the world, but may matter in
very low kernel memory situations.
[ v2: fix it for all occurrences of sysctl_vfs_cache_pressure ]
Signed-off-by: Glauber Costa <glommer@openvz.org>
Reviewed-by: Carlos Maiolino <cmaiolino@redhat.com>
Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Acked-by: Mel Gorman <mgorman@suse.de>
CC: Dave Chinner <david@fromorbit.com>
CC: "Theodore Ts'o" <tytso@mit.edu>
CC: Al Viro <viro@zeniv.linux.org.uk>
---
fs/gfs2/glock.c | 2 +-
fs/gfs2/quota.c | 2 +-
fs/mbcache.c | 2 +-
fs/nfs/dir.c | 2 +-
fs/quota/dquot.c | 5 ++---
fs/super.c | 14 +++++++-------
fs/xfs/xfs_qm.c | 2 +-
include/linux/dcache.h | 4 ++++
8 files changed, 18 insertions(+), 15 deletions(-)
diff --git a/fs/gfs2/glock.c b/fs/gfs2/glock.c
index 9435384..3bd2748 100644
--- a/fs/gfs2/glock.c
+++ b/fs/gfs2/glock.c
@@ -1463,7 +1463,7 @@ static int gfs2_shrink_glock_memory(struct shrinker *shrink,
gfs2_scan_glock_lru(sc->nr_to_scan);
}
- return (atomic_read(&lru_count) / 100) * sysctl_vfs_cache_pressure;
+ return vfs_pressure_ratio(atomic_read(&lru_count));
}
static struct shrinker glock_shrinker = {
diff --git a/fs/gfs2/quota.c b/fs/gfs2/quota.c
index c7c840e..5c14206 100644
--- a/fs/gfs2/quota.c
+++ b/fs/gfs2/quota.c
@@ -114,7 +114,7 @@ int gfs2_shrink_qd_memory(struct shrinker *shrink, struct shrink_control *sc)
spin_unlock(&qd_lru_lock);
out:
- return (atomic_read(&qd_lru_count) * sysctl_vfs_cache_pressure) / 100;
+ return vfs_pressure_ratio(atomic_read(&qd_lru_count));
}
static u64 qd2index(struct gfs2_quota_data *qd)
diff --git a/fs/mbcache.c b/fs/mbcache.c
index 8c32ef3..5eb0476 100644
--- a/fs/mbcache.c
+++ b/fs/mbcache.c
@@ -189,7 +189,7 @@ mb_cache_shrink_fn(struct shrinker *shrink, struct shrink_control *sc)
list_for_each_entry_safe(entry, tmp, &free_list, e_lru_list) {
__mb_cache_entry_forget(entry, gfp_mask);
}
- return (count / 100) * sysctl_vfs_cache_pressure;
+ return vfs_pressure_ratio(count);
}
diff --git a/fs/nfs/dir.c b/fs/nfs/dir.c
index e093e73..54d7c47 100644
--- a/fs/nfs/dir.c
+++ b/fs/nfs/dir.c
@@ -1998,7 +1998,7 @@ remove_lru_entry:
}
spin_unlock(&nfs_access_lru_lock);
nfs_access_free_list(&head);
- return (atomic_long_read(&nfs_access_nr_entries) / 100) * sysctl_vfs_cache_pressure;
+ return vfs_pressure_ratio(atomic_long_read(&nfs_access_nr_entries));
}
static void __nfs_access_zap_cache(struct nfs_inode *nfsi, struct list_head *head)
diff --git a/fs/quota/dquot.c b/fs/quota/dquot.c
index 3e64169..762b09c 100644
--- a/fs/quota/dquot.c
+++ b/fs/quota/dquot.c
@@ -719,9 +719,8 @@ static int shrink_dqcache_memory(struct shrinker *shrink,
prune_dqcache(nr);
spin_unlock(&dq_list_lock);
}
- return ((unsigned)
- percpu_counter_read_positive(&dqstats.counter[DQST_FREE_DQUOTS])
- /100) * sysctl_vfs_cache_pressure;
+ return vfs_pressure_ratio(
+ percpu_counter_read_positive(&dqstats.counter[DQST_FREE_DQUOTS]));
}
static struct shrinker dqcache_shrinker = {
diff --git a/fs/super.c b/fs/super.c
index 7465d43..2a37fd6 100644
--- a/fs/super.c
+++ b/fs/super.c
@@ -82,13 +82,13 @@ static int prune_super(struct shrinker *shrink, struct shrink_control *sc)
int inodes;
/* proportion the scan between the caches */
- dentries = (sc->nr_to_scan * sb->s_nr_dentry_unused) /
- total_objects;
- inodes = (sc->nr_to_scan * sb->s_nr_inodes_unused) /
- total_objects;
+ dentries = mult_frac(sc->nr_to_scan, sb->s_nr_dentry_unused,
+ total_objects);
+ inodes = mult_frac(sc->nr_to_scan, sb->s_nr_inodes_unused,
+ total_objects);
if (fs_objects)
- fs_objects = (sc->nr_to_scan * fs_objects) /
- total_objects;
+ fs_objects = mult_frac(sc->nr_to_scan, fs_objects,
+ total_objects);
/*
* prune the dcache first as the icache is pinned by it, then
* prune the icache, followed by the filesystem specific caches
@@ -104,7 +104,7 @@ static int prune_super(struct shrinker *shrink, struct shrink_control *sc)
sb->s_nr_inodes_unused + fs_objects;
}
- total_objects = (total_objects / 100) * sysctl_vfs_cache_pressure;
+ total_objects = vfs_pressure_ratio(total_objects);
drop_super(sb);
return total_objects;
}
diff --git a/fs/xfs/xfs_qm.c b/fs/xfs/xfs_qm.c
index f41702b..7ade175 100644
--- a/fs/xfs/xfs_qm.c
+++ b/fs/xfs/xfs_qm.c
@@ -1585,7 +1585,7 @@ xfs_qm_shake(
}
out:
- return (qi->qi_lru_count / 100) * sysctl_vfs_cache_pressure;
+ return vfs_pressure_ratio(qi->qi_lru_count);
}
/*
diff --git a/include/linux/dcache.h b/include/linux/dcache.h
index 1a6bb81..4d24a12 100644
--- a/include/linux/dcache.h
+++ b/include/linux/dcache.h
@@ -411,4 +411,8 @@ static inline bool d_mountpoint(struct dentry *dentry)
extern int sysctl_vfs_cache_pressure;
+static inline unsigned long vfs_pressure_ratio(unsigned long val)
+{
+ return mult_frac(val, sysctl_vfs_cache_pressure, 100);
+}
#endif /* __LINUX_DCACHE_H */
--
1.8.1.4
--
To unsubscribe, send a message with 'unsubscribe linux-mm' in
the body to majordomo@kvack.org. For more info on Linux MM,
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^ permalink raw reply related [flat|nested] 151+ messages in thread
* [PATCH v6 02/31] dcache: convert dentry_stat.nr_unused to per-cpu counters
2013-05-12 18:13 ` Glauber Costa
(?)
@ 2013-05-12 18:13 ` Glauber Costa
-1 siblings, 0 replies; 151+ messages in thread
From: Glauber Costa @ 2013-05-12 18:13 UTC (permalink / raw)
To: linux-mm
Cc: cgroups, Andrew Morton, Greg Thelen, kamezawa.hiroyu,
Michal Hocko, Johannes Weiner, linux-fsdevel, Dave Chinner,
Dave Chinner
From: Dave Chinner <dchinner@redhat.com>
Before we split up the dcache_lru_lock, the unused dentry counter
needs to be made independent of the global dcache_lru_lock. Convert
it to per-cpu counters to do this.
[ v5: comment about possible cpus ]
Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Acked-by: Mel Gorman <mgorman@suse.de>
---
fs/dcache.c | 18 +++++++++++++++---
1 file changed, 15 insertions(+), 3 deletions(-)
diff --git a/fs/dcache.c b/fs/dcache.c
index f09b908..cb304f4 100644
--- a/fs/dcache.c
+++ b/fs/dcache.c
@@ -118,8 +118,10 @@ struct dentry_stat_t dentry_stat = {
};
static DEFINE_PER_CPU(unsigned int, nr_dentry);
+static DEFINE_PER_CPU(unsigned int, nr_dentry_unused);
#if defined(CONFIG_SYSCTL) && defined(CONFIG_PROC_FS)
+/* scan possible cpus instead of online and avoid worrying about CPU hotplug. */
static int get_nr_dentry(void)
{
int i;
@@ -129,10 +131,20 @@ static int get_nr_dentry(void)
return sum < 0 ? 0 : sum;
}
+static int get_nr_dentry_unused(void)
+{
+ int i;
+ int sum = 0;
+ for_each_possible_cpu(i)
+ sum += per_cpu(nr_dentry_unused, i);
+ return sum < 0 ? 0 : sum;
+}
+
int proc_nr_dentry(ctl_table *table, int write, void __user *buffer,
size_t *lenp, loff_t *ppos)
{
dentry_stat.nr_dentry = get_nr_dentry();
+ dentry_stat.nr_unused = get_nr_dentry_unused();
return proc_dointvec(table, write, buffer, lenp, ppos);
}
#endif
@@ -312,7 +324,7 @@ static void dentry_lru_add(struct dentry *dentry)
spin_lock(&dcache_lru_lock);
list_add(&dentry->d_lru, &dentry->d_sb->s_dentry_lru);
dentry->d_sb->s_nr_dentry_unused++;
- dentry_stat.nr_unused++;
+ this_cpu_inc(nr_dentry_unused);
spin_unlock(&dcache_lru_lock);
}
}
@@ -322,7 +334,7 @@ static void __dentry_lru_del(struct dentry *dentry)
list_del_init(&dentry->d_lru);
dentry->d_flags &= ~DCACHE_SHRINK_LIST;
dentry->d_sb->s_nr_dentry_unused--;
- dentry_stat.nr_unused--;
+ this_cpu_dec(nr_dentry_unused);
}
/*
@@ -343,7 +355,7 @@ static void dentry_lru_move_list(struct dentry *dentry, struct list_head *list)
if (list_empty(&dentry->d_lru)) {
list_add_tail(&dentry->d_lru, list);
dentry->d_sb->s_nr_dentry_unused++;
- dentry_stat.nr_unused++;
+ this_cpu_inc(nr_dentry_unused);
} else {
list_move_tail(&dentry->d_lru, list);
}
--
1.8.1.4
^ permalink raw reply related [flat|nested] 151+ messages in thread* [PATCH v6 02/31] dcache: convert dentry_stat.nr_unused to per-cpu counters
@ 2013-05-12 18:13 ` Glauber Costa
0 siblings, 0 replies; 151+ messages in thread
From: Glauber Costa @ 2013-05-12 18:13 UTC (permalink / raw)
To: linux-mm
Cc: cgroups, Andrew Morton, Greg Thelen, kamezawa.hiroyu,
Michal Hocko, Johannes Weiner, linux-fsdevel, Dave Chinner,
Dave Chinner
From: Dave Chinner <dchinner@redhat.com>
Before we split up the dcache_lru_lock, the unused dentry counter
needs to be made independent of the global dcache_lru_lock. Convert
it to per-cpu counters to do this.
[ v5: comment about possible cpus ]
Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Acked-by: Mel Gorman <mgorman@suse.de>
---
fs/dcache.c | 18 +++++++++++++++---
1 file changed, 15 insertions(+), 3 deletions(-)
diff --git a/fs/dcache.c b/fs/dcache.c
index f09b908..cb304f4 100644
--- a/fs/dcache.c
+++ b/fs/dcache.c
@@ -118,8 +118,10 @@ struct dentry_stat_t dentry_stat = {
};
static DEFINE_PER_CPU(unsigned int, nr_dentry);
+static DEFINE_PER_CPU(unsigned int, nr_dentry_unused);
#if defined(CONFIG_SYSCTL) && defined(CONFIG_PROC_FS)
+/* scan possible cpus instead of online and avoid worrying about CPU hotplug. */
static int get_nr_dentry(void)
{
int i;
@@ -129,10 +131,20 @@ static int get_nr_dentry(void)
return sum < 0 ? 0 : sum;
}
+static int get_nr_dentry_unused(void)
+{
+ int i;
+ int sum = 0;
+ for_each_possible_cpu(i)
+ sum += per_cpu(nr_dentry_unused, i);
+ return sum < 0 ? 0 : sum;
+}
+
int proc_nr_dentry(ctl_table *table, int write, void __user *buffer,
size_t *lenp, loff_t *ppos)
{
dentry_stat.nr_dentry = get_nr_dentry();
+ dentry_stat.nr_unused = get_nr_dentry_unused();
return proc_dointvec(table, write, buffer, lenp, ppos);
}
#endif
@@ -312,7 +324,7 @@ static void dentry_lru_add(struct dentry *dentry)
spin_lock(&dcache_lru_lock);
list_add(&dentry->d_lru, &dentry->d_sb->s_dentry_lru);
dentry->d_sb->s_nr_dentry_unused++;
- dentry_stat.nr_unused++;
+ this_cpu_inc(nr_dentry_unused);
spin_unlock(&dcache_lru_lock);
}
}
@@ -322,7 +334,7 @@ static void __dentry_lru_del(struct dentry *dentry)
list_del_init(&dentry->d_lru);
dentry->d_flags &= ~DCACHE_SHRINK_LIST;
dentry->d_sb->s_nr_dentry_unused--;
- dentry_stat.nr_unused--;
+ this_cpu_dec(nr_dentry_unused);
}
/*
@@ -343,7 +355,7 @@ static void dentry_lru_move_list(struct dentry *dentry, struct list_head *list)
if (list_empty(&dentry->d_lru)) {
list_add_tail(&dentry->d_lru, list);
dentry->d_sb->s_nr_dentry_unused++;
- dentry_stat.nr_unused++;
+ this_cpu_inc(nr_dentry_unused);
} else {
list_move_tail(&dentry->d_lru, list);
}
--
1.8.1.4
^ permalink raw reply related [flat|nested] 151+ messages in thread* [PATCH v6 02/31] dcache: convert dentry_stat.nr_unused to per-cpu counters
@ 2013-05-12 18:13 ` Glauber Costa
0 siblings, 0 replies; 151+ messages in thread
From: Glauber Costa @ 2013-05-12 18:13 UTC (permalink / raw)
To: linux-mm
Cc: cgroups, Andrew Morton, Greg Thelen, kamezawa.hiroyu,
Michal Hocko, Johannes Weiner, linux-fsdevel, Dave Chinner,
Dave Chinner
From: Dave Chinner <dchinner@redhat.com>
Before we split up the dcache_lru_lock, the unused dentry counter
needs to be made independent of the global dcache_lru_lock. Convert
it to per-cpu counters to do this.
[ v5: comment about possible cpus ]
Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Acked-by: Mel Gorman <mgorman@suse.de>
---
fs/dcache.c | 18 +++++++++++++++---
1 file changed, 15 insertions(+), 3 deletions(-)
diff --git a/fs/dcache.c b/fs/dcache.c
index f09b908..cb304f4 100644
--- a/fs/dcache.c
+++ b/fs/dcache.c
@@ -118,8 +118,10 @@ struct dentry_stat_t dentry_stat = {
};
static DEFINE_PER_CPU(unsigned int, nr_dentry);
+static DEFINE_PER_CPU(unsigned int, nr_dentry_unused);
#if defined(CONFIG_SYSCTL) && defined(CONFIG_PROC_FS)
+/* scan possible cpus instead of online and avoid worrying about CPU hotplug. */
static int get_nr_dentry(void)
{
int i;
@@ -129,10 +131,20 @@ static int get_nr_dentry(void)
return sum < 0 ? 0 : sum;
}
+static int get_nr_dentry_unused(void)
+{
+ int i;
+ int sum = 0;
+ for_each_possible_cpu(i)
+ sum += per_cpu(nr_dentry_unused, i);
+ return sum < 0 ? 0 : sum;
+}
+
int proc_nr_dentry(ctl_table *table, int write, void __user *buffer,
size_t *lenp, loff_t *ppos)
{
dentry_stat.nr_dentry = get_nr_dentry();
+ dentry_stat.nr_unused = get_nr_dentry_unused();
return proc_dointvec(table, write, buffer, lenp, ppos);
}
#endif
@@ -312,7 +324,7 @@ static void dentry_lru_add(struct dentry *dentry)
spin_lock(&dcache_lru_lock);
list_add(&dentry->d_lru, &dentry->d_sb->s_dentry_lru);
dentry->d_sb->s_nr_dentry_unused++;
- dentry_stat.nr_unused++;
+ this_cpu_inc(nr_dentry_unused);
spin_unlock(&dcache_lru_lock);
}
}
@@ -322,7 +334,7 @@ static void __dentry_lru_del(struct dentry *dentry)
list_del_init(&dentry->d_lru);
dentry->d_flags &= ~DCACHE_SHRINK_LIST;
dentry->d_sb->s_nr_dentry_unused--;
- dentry_stat.nr_unused--;
+ this_cpu_dec(nr_dentry_unused);
}
/*
@@ -343,7 +355,7 @@ static void dentry_lru_move_list(struct dentry *dentry, struct list_head *list)
if (list_empty(&dentry->d_lru)) {
list_add_tail(&dentry->d_lru, list);
dentry->d_sb->s_nr_dentry_unused++;
- dentry_stat.nr_unused++;
+ this_cpu_inc(nr_dentry_unused);
} else {
list_move_tail(&dentry->d_lru, list);
}
--
1.8.1.4
--
To unsubscribe, send a message with 'unsubscribe linux-mm' in
the body to majordomo@kvack.org. For more info on Linux MM,
see: http://www.linux-mm.org/ .
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^ permalink raw reply related [flat|nested] 151+ messages in thread
* [PATCH v6 03/31] dentry: move to per-sb LRU locks
2013-05-12 18:13 ` Glauber Costa
(?)
@ 2013-05-12 18:13 ` Glauber Costa
-1 siblings, 0 replies; 151+ messages in thread
From: Glauber Costa @ 2013-05-12 18:13 UTC (permalink / raw)
To: linux-mm
Cc: cgroups, Andrew Morton, Greg Thelen, kamezawa.hiroyu,
Michal Hocko, Johannes Weiner, linux-fsdevel, Dave Chinner,
Dave Chinner
From: Dave Chinner <dchinner@redhat.com>
With the dentry LRUs being per-sb structures, there is no real need
for a global dentry_lru_lock. The locking can be made more
fine-grained by moving to a per-sb LRU lock, isolating the LRU
operations of different filesytsems completely from each other.
Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Acked-by: Mel Gorman <mgorman@suse.de>
---
fs/dcache.c | 33 ++++++++++++++++-----------------
fs/super.c | 1 +
include/linux/fs.h | 4 +++-
3 files changed, 20 insertions(+), 18 deletions(-)
diff --git a/fs/dcache.c b/fs/dcache.c
index cb304f4..795c15d 100644
--- a/fs/dcache.c
+++ b/fs/dcache.c
@@ -48,7 +48,7 @@
* - the dcache hash table
* s_anon bl list spinlock protects:
* - the s_anon list (see __d_drop)
- * dcache_lru_lock protects:
+ * dentry->d_sb->s_dentry_lru_lock protects:
* - the dcache lru lists and counters
* d_lock protects:
* - d_flags
@@ -63,7 +63,7 @@
* Ordering:
* dentry->d_inode->i_lock
* dentry->d_lock
- * dcache_lru_lock
+ * dentry->d_sb->s_dentry_lru_lock
* dcache_hash_bucket lock
* s_anon lock
*
@@ -81,7 +81,6 @@
int sysctl_vfs_cache_pressure __read_mostly = 100;
EXPORT_SYMBOL_GPL(sysctl_vfs_cache_pressure);
-static __cacheline_aligned_in_smp DEFINE_SPINLOCK(dcache_lru_lock);
__cacheline_aligned_in_smp DEFINE_SEQLOCK(rename_lock);
EXPORT_SYMBOL(rename_lock);
@@ -321,11 +320,11 @@ static void dentry_unlink_inode(struct dentry * dentry)
static void dentry_lru_add(struct dentry *dentry)
{
if (list_empty(&dentry->d_lru)) {
- spin_lock(&dcache_lru_lock);
+ spin_lock(&dentry->d_sb->s_dentry_lru_lock);
list_add(&dentry->d_lru, &dentry->d_sb->s_dentry_lru);
dentry->d_sb->s_nr_dentry_unused++;
this_cpu_inc(nr_dentry_unused);
- spin_unlock(&dcache_lru_lock);
+ spin_unlock(&dentry->d_sb->s_dentry_lru_lock);
}
}
@@ -343,15 +342,15 @@ static void __dentry_lru_del(struct dentry *dentry)
static void dentry_lru_del(struct dentry *dentry)
{
if (!list_empty(&dentry->d_lru)) {
- spin_lock(&dcache_lru_lock);
+ spin_lock(&dentry->d_sb->s_dentry_lru_lock);
__dentry_lru_del(dentry);
- spin_unlock(&dcache_lru_lock);
+ spin_unlock(&dentry->d_sb->s_dentry_lru_lock);
}
}
static void dentry_lru_move_list(struct dentry *dentry, struct list_head *list)
{
- spin_lock(&dcache_lru_lock);
+ spin_lock(&dentry->d_sb->s_dentry_lru_lock);
if (list_empty(&dentry->d_lru)) {
list_add_tail(&dentry->d_lru, list);
dentry->d_sb->s_nr_dentry_unused++;
@@ -359,7 +358,7 @@ static void dentry_lru_move_list(struct dentry *dentry, struct list_head *list)
} else {
list_move_tail(&dentry->d_lru, list);
}
- spin_unlock(&dcache_lru_lock);
+ spin_unlock(&dentry->d_sb->s_dentry_lru_lock);
}
/**
@@ -839,14 +838,14 @@ void prune_dcache_sb(struct super_block *sb, int count)
LIST_HEAD(tmp);
relock:
- spin_lock(&dcache_lru_lock);
+ spin_lock(&sb->s_dentry_lru_lock);
while (!list_empty(&sb->s_dentry_lru)) {
dentry = list_entry(sb->s_dentry_lru.prev,
struct dentry, d_lru);
BUG_ON(dentry->d_sb != sb);
if (!spin_trylock(&dentry->d_lock)) {
- spin_unlock(&dcache_lru_lock);
+ spin_unlock(&sb->s_dentry_lru_lock);
cpu_relax();
goto relock;
}
@@ -862,11 +861,11 @@ relock:
if (!--count)
break;
}
- cond_resched_lock(&dcache_lru_lock);
+ cond_resched_lock(&sb->s_dentry_lru_lock);
}
if (!list_empty(&referenced))
list_splice(&referenced, &sb->s_dentry_lru);
- spin_unlock(&dcache_lru_lock);
+ spin_unlock(&sb->s_dentry_lru_lock);
shrink_dentry_list(&tmp);
}
@@ -882,14 +881,14 @@ void shrink_dcache_sb(struct super_block *sb)
{
LIST_HEAD(tmp);
- spin_lock(&dcache_lru_lock);
+ spin_lock(&sb->s_dentry_lru_lock);
while (!list_empty(&sb->s_dentry_lru)) {
list_splice_init(&sb->s_dentry_lru, &tmp);
- spin_unlock(&dcache_lru_lock);
+ spin_unlock(&sb->s_dentry_lru_lock);
shrink_dentry_list(&tmp);
- spin_lock(&dcache_lru_lock);
+ spin_lock(&sb->s_dentry_lru_lock);
}
- spin_unlock(&dcache_lru_lock);
+ spin_unlock(&sb->s_dentry_lru_lock);
}
EXPORT_SYMBOL(shrink_dcache_sb);
diff --git a/fs/super.c b/fs/super.c
index 2a37fd6..0be75fb 100644
--- a/fs/super.c
+++ b/fs/super.c
@@ -182,6 +182,7 @@ static struct super_block *alloc_super(struct file_system_type *type, int flags)
INIT_HLIST_BL_HEAD(&s->s_anon);
INIT_LIST_HEAD(&s->s_inodes);
INIT_LIST_HEAD(&s->s_dentry_lru);
+ spin_lock_init(&s->s_dentry_lru_lock);
INIT_LIST_HEAD(&s->s_inode_lru);
spin_lock_init(&s->s_inode_lru_lock);
INIT_LIST_HEAD(&s->s_mounts);
diff --git a/include/linux/fs.h b/include/linux/fs.h
index 0a9a6766..67e1040 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -1263,7 +1263,9 @@ struct super_block {
struct list_head s_files;
#endif
struct list_head s_mounts; /* list of mounts; _not_ for fs use */
- /* s_dentry_lru, s_nr_dentry_unused protected by dcache.c lru locks */
+
+ /* s_dentry_lru_lock protects s_dentry_lru and s_nr_dentry_unused */
+ spinlock_t s_dentry_lru_lock ____cacheline_aligned_in_smp;
struct list_head s_dentry_lru; /* unused dentry lru */
int s_nr_dentry_unused; /* # of dentry on lru */
--
1.8.1.4
^ permalink raw reply related [flat|nested] 151+ messages in thread* [PATCH v6 03/31] dentry: move to per-sb LRU locks
@ 2013-05-12 18:13 ` Glauber Costa
0 siblings, 0 replies; 151+ messages in thread
From: Glauber Costa @ 2013-05-12 18:13 UTC (permalink / raw)
To: linux-mm
Cc: cgroups, Andrew Morton, Greg Thelen, kamezawa.hiroyu,
Michal Hocko, Johannes Weiner, linux-fsdevel, Dave Chinner,
Dave Chinner
From: Dave Chinner <dchinner@redhat.com>
With the dentry LRUs being per-sb structures, there is no real need
for a global dentry_lru_lock. The locking can be made more
fine-grained by moving to a per-sb LRU lock, isolating the LRU
operations of different filesytsems completely from each other.
Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Acked-by: Mel Gorman <mgorman@suse.de>
---
fs/dcache.c | 33 ++++++++++++++++-----------------
fs/super.c | 1 +
include/linux/fs.h | 4 +++-
3 files changed, 20 insertions(+), 18 deletions(-)
diff --git a/fs/dcache.c b/fs/dcache.c
index cb304f4..795c15d 100644
--- a/fs/dcache.c
+++ b/fs/dcache.c
@@ -48,7 +48,7 @@
* - the dcache hash table
* s_anon bl list spinlock protects:
* - the s_anon list (see __d_drop)
- * dcache_lru_lock protects:
+ * dentry->d_sb->s_dentry_lru_lock protects:
* - the dcache lru lists and counters
* d_lock protects:
* - d_flags
@@ -63,7 +63,7 @@
* Ordering:
* dentry->d_inode->i_lock
* dentry->d_lock
- * dcache_lru_lock
+ * dentry->d_sb->s_dentry_lru_lock
* dcache_hash_bucket lock
* s_anon lock
*
@@ -81,7 +81,6 @@
int sysctl_vfs_cache_pressure __read_mostly = 100;
EXPORT_SYMBOL_GPL(sysctl_vfs_cache_pressure);
-static __cacheline_aligned_in_smp DEFINE_SPINLOCK(dcache_lru_lock);
__cacheline_aligned_in_smp DEFINE_SEQLOCK(rename_lock);
EXPORT_SYMBOL(rename_lock);
@@ -321,11 +320,11 @@ static void dentry_unlink_inode(struct dentry * dentry)
static void dentry_lru_add(struct dentry *dentry)
{
if (list_empty(&dentry->d_lru)) {
- spin_lock(&dcache_lru_lock);
+ spin_lock(&dentry->d_sb->s_dentry_lru_lock);
list_add(&dentry->d_lru, &dentry->d_sb->s_dentry_lru);
dentry->d_sb->s_nr_dentry_unused++;
this_cpu_inc(nr_dentry_unused);
- spin_unlock(&dcache_lru_lock);
+ spin_unlock(&dentry->d_sb->s_dentry_lru_lock);
}
}
@@ -343,15 +342,15 @@ static void __dentry_lru_del(struct dentry *dentry)
static void dentry_lru_del(struct dentry *dentry)
{
if (!list_empty(&dentry->d_lru)) {
- spin_lock(&dcache_lru_lock);
+ spin_lock(&dentry->d_sb->s_dentry_lru_lock);
__dentry_lru_del(dentry);
- spin_unlock(&dcache_lru_lock);
+ spin_unlock(&dentry->d_sb->s_dentry_lru_lock);
}
}
static void dentry_lru_move_list(struct dentry *dentry, struct list_head *list)
{
- spin_lock(&dcache_lru_lock);
+ spin_lock(&dentry->d_sb->s_dentry_lru_lock);
if (list_empty(&dentry->d_lru)) {
list_add_tail(&dentry->d_lru, list);
dentry->d_sb->s_nr_dentry_unused++;
@@ -359,7 +358,7 @@ static void dentry_lru_move_list(struct dentry *dentry, struct list_head *list)
} else {
list_move_tail(&dentry->d_lru, list);
}
- spin_unlock(&dcache_lru_lock);
+ spin_unlock(&dentry->d_sb->s_dentry_lru_lock);
}
/**
@@ -839,14 +838,14 @@ void prune_dcache_sb(struct super_block *sb, int count)
LIST_HEAD(tmp);
relock:
- spin_lock(&dcache_lru_lock);
+ spin_lock(&sb->s_dentry_lru_lock);
while (!list_empty(&sb->s_dentry_lru)) {
dentry = list_entry(sb->s_dentry_lru.prev,
struct dentry, d_lru);
BUG_ON(dentry->d_sb != sb);
if (!spin_trylock(&dentry->d_lock)) {
- spin_unlock(&dcache_lru_lock);
+ spin_unlock(&sb->s_dentry_lru_lock);
cpu_relax();
goto relock;
}
@@ -862,11 +861,11 @@ relock:
if (!--count)
break;
}
- cond_resched_lock(&dcache_lru_lock);
+ cond_resched_lock(&sb->s_dentry_lru_lock);
}
if (!list_empty(&referenced))
list_splice(&referenced, &sb->s_dentry_lru);
- spin_unlock(&dcache_lru_lock);
+ spin_unlock(&sb->s_dentry_lru_lock);
shrink_dentry_list(&tmp);
}
@@ -882,14 +881,14 @@ void shrink_dcache_sb(struct super_block *sb)
{
LIST_HEAD(tmp);
- spin_lock(&dcache_lru_lock);
+ spin_lock(&sb->s_dentry_lru_lock);
while (!list_empty(&sb->s_dentry_lru)) {
list_splice_init(&sb->s_dentry_lru, &tmp);
- spin_unlock(&dcache_lru_lock);
+ spin_unlock(&sb->s_dentry_lru_lock);
shrink_dentry_list(&tmp);
- spin_lock(&dcache_lru_lock);
+ spin_lock(&sb->s_dentry_lru_lock);
}
- spin_unlock(&dcache_lru_lock);
+ spin_unlock(&sb->s_dentry_lru_lock);
}
EXPORT_SYMBOL(shrink_dcache_sb);
diff --git a/fs/super.c b/fs/super.c
index 2a37fd6..0be75fb 100644
--- a/fs/super.c
+++ b/fs/super.c
@@ -182,6 +182,7 @@ static struct super_block *alloc_super(struct file_system_type *type, int flags)
INIT_HLIST_BL_HEAD(&s->s_anon);
INIT_LIST_HEAD(&s->s_inodes);
INIT_LIST_HEAD(&s->s_dentry_lru);
+ spin_lock_init(&s->s_dentry_lru_lock);
INIT_LIST_HEAD(&s->s_inode_lru);
spin_lock_init(&s->s_inode_lru_lock);
INIT_LIST_HEAD(&s->s_mounts);
diff --git a/include/linux/fs.h b/include/linux/fs.h
index 0a9a6766..67e1040 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -1263,7 +1263,9 @@ struct super_block {
struct list_head s_files;
#endif
struct list_head s_mounts; /* list of mounts; _not_ for fs use */
- /* s_dentry_lru, s_nr_dentry_unused protected by dcache.c lru locks */
+
+ /* s_dentry_lru_lock protects s_dentry_lru and s_nr_dentry_unused */
+ spinlock_t s_dentry_lru_lock ____cacheline_aligned_in_smp;
struct list_head s_dentry_lru; /* unused dentry lru */
int s_nr_dentry_unused; /* # of dentry on lru */
--
1.8.1.4
^ permalink raw reply related [flat|nested] 151+ messages in thread* [PATCH v6 03/31] dentry: move to per-sb LRU locks
@ 2013-05-12 18:13 ` Glauber Costa
0 siblings, 0 replies; 151+ messages in thread
From: Glauber Costa @ 2013-05-12 18:13 UTC (permalink / raw)
To: linux-mm
Cc: cgroups, Andrew Morton, Greg Thelen, kamezawa.hiroyu,
Michal Hocko, Johannes Weiner, linux-fsdevel, Dave Chinner,
Dave Chinner
From: Dave Chinner <dchinner@redhat.com>
With the dentry LRUs being per-sb structures, there is no real need
for a global dentry_lru_lock. The locking can be made more
fine-grained by moving to a per-sb LRU lock, isolating the LRU
operations of different filesytsems completely from each other.
Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Acked-by: Mel Gorman <mgorman@suse.de>
---
fs/dcache.c | 33 ++++++++++++++++-----------------
fs/super.c | 1 +
include/linux/fs.h | 4 +++-
3 files changed, 20 insertions(+), 18 deletions(-)
diff --git a/fs/dcache.c b/fs/dcache.c
index cb304f4..795c15d 100644
--- a/fs/dcache.c
+++ b/fs/dcache.c
@@ -48,7 +48,7 @@
* - the dcache hash table
* s_anon bl list spinlock protects:
* - the s_anon list (see __d_drop)
- * dcache_lru_lock protects:
+ * dentry->d_sb->s_dentry_lru_lock protects:
* - the dcache lru lists and counters
* d_lock protects:
* - d_flags
@@ -63,7 +63,7 @@
* Ordering:
* dentry->d_inode->i_lock
* dentry->d_lock
- * dcache_lru_lock
+ * dentry->d_sb->s_dentry_lru_lock
* dcache_hash_bucket lock
* s_anon lock
*
@@ -81,7 +81,6 @@
int sysctl_vfs_cache_pressure __read_mostly = 100;
EXPORT_SYMBOL_GPL(sysctl_vfs_cache_pressure);
-static __cacheline_aligned_in_smp DEFINE_SPINLOCK(dcache_lru_lock);
__cacheline_aligned_in_smp DEFINE_SEQLOCK(rename_lock);
EXPORT_SYMBOL(rename_lock);
@@ -321,11 +320,11 @@ static void dentry_unlink_inode(struct dentry * dentry)
static void dentry_lru_add(struct dentry *dentry)
{
if (list_empty(&dentry->d_lru)) {
- spin_lock(&dcache_lru_lock);
+ spin_lock(&dentry->d_sb->s_dentry_lru_lock);
list_add(&dentry->d_lru, &dentry->d_sb->s_dentry_lru);
dentry->d_sb->s_nr_dentry_unused++;
this_cpu_inc(nr_dentry_unused);
- spin_unlock(&dcache_lru_lock);
+ spin_unlock(&dentry->d_sb->s_dentry_lru_lock);
}
}
@@ -343,15 +342,15 @@ static void __dentry_lru_del(struct dentry *dentry)
static void dentry_lru_del(struct dentry *dentry)
{
if (!list_empty(&dentry->d_lru)) {
- spin_lock(&dcache_lru_lock);
+ spin_lock(&dentry->d_sb->s_dentry_lru_lock);
__dentry_lru_del(dentry);
- spin_unlock(&dcache_lru_lock);
+ spin_unlock(&dentry->d_sb->s_dentry_lru_lock);
}
}
static void dentry_lru_move_list(struct dentry *dentry, struct list_head *list)
{
- spin_lock(&dcache_lru_lock);
+ spin_lock(&dentry->d_sb->s_dentry_lru_lock);
if (list_empty(&dentry->d_lru)) {
list_add_tail(&dentry->d_lru, list);
dentry->d_sb->s_nr_dentry_unused++;
@@ -359,7 +358,7 @@ static void dentry_lru_move_list(struct dentry *dentry, struct list_head *list)
} else {
list_move_tail(&dentry->d_lru, list);
}
- spin_unlock(&dcache_lru_lock);
+ spin_unlock(&dentry->d_sb->s_dentry_lru_lock);
}
/**
@@ -839,14 +838,14 @@ void prune_dcache_sb(struct super_block *sb, int count)
LIST_HEAD(tmp);
relock:
- spin_lock(&dcache_lru_lock);
+ spin_lock(&sb->s_dentry_lru_lock);
while (!list_empty(&sb->s_dentry_lru)) {
dentry = list_entry(sb->s_dentry_lru.prev,
struct dentry, d_lru);
BUG_ON(dentry->d_sb != sb);
if (!spin_trylock(&dentry->d_lock)) {
- spin_unlock(&dcache_lru_lock);
+ spin_unlock(&sb->s_dentry_lru_lock);
cpu_relax();
goto relock;
}
@@ -862,11 +861,11 @@ relock:
if (!--count)
break;
}
- cond_resched_lock(&dcache_lru_lock);
+ cond_resched_lock(&sb->s_dentry_lru_lock);
}
if (!list_empty(&referenced))
list_splice(&referenced, &sb->s_dentry_lru);
- spin_unlock(&dcache_lru_lock);
+ spin_unlock(&sb->s_dentry_lru_lock);
shrink_dentry_list(&tmp);
}
@@ -882,14 +881,14 @@ void shrink_dcache_sb(struct super_block *sb)
{
LIST_HEAD(tmp);
- spin_lock(&dcache_lru_lock);
+ spin_lock(&sb->s_dentry_lru_lock);
while (!list_empty(&sb->s_dentry_lru)) {
list_splice_init(&sb->s_dentry_lru, &tmp);
- spin_unlock(&dcache_lru_lock);
+ spin_unlock(&sb->s_dentry_lru_lock);
shrink_dentry_list(&tmp);
- spin_lock(&dcache_lru_lock);
+ spin_lock(&sb->s_dentry_lru_lock);
}
- spin_unlock(&dcache_lru_lock);
+ spin_unlock(&sb->s_dentry_lru_lock);
}
EXPORT_SYMBOL(shrink_dcache_sb);
diff --git a/fs/super.c b/fs/super.c
index 2a37fd6..0be75fb 100644
--- a/fs/super.c
+++ b/fs/super.c
@@ -182,6 +182,7 @@ static struct super_block *alloc_super(struct file_system_type *type, int flags)
INIT_HLIST_BL_HEAD(&s->s_anon);
INIT_LIST_HEAD(&s->s_inodes);
INIT_LIST_HEAD(&s->s_dentry_lru);
+ spin_lock_init(&s->s_dentry_lru_lock);
INIT_LIST_HEAD(&s->s_inode_lru);
spin_lock_init(&s->s_inode_lru_lock);
INIT_LIST_HEAD(&s->s_mounts);
diff --git a/include/linux/fs.h b/include/linux/fs.h
index 0a9a6766..67e1040 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -1263,7 +1263,9 @@ struct super_block {
struct list_head s_files;
#endif
struct list_head s_mounts; /* list of mounts; _not_ for fs use */
- /* s_dentry_lru, s_nr_dentry_unused protected by dcache.c lru locks */
+
+ /* s_dentry_lru_lock protects s_dentry_lru and s_nr_dentry_unused */
+ spinlock_t s_dentry_lru_lock ____cacheline_aligned_in_smp;
struct list_head s_dentry_lru; /* unused dentry lru */
int s_nr_dentry_unused; /* # of dentry on lru */
--
1.8.1.4
--
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^ permalink raw reply related [flat|nested] 151+ messages in thread
* [PATCH v6 04/31] dcache: remove dentries from LRU before putting on dispose list
2013-05-12 18:13 ` Glauber Costa
(?)
@ 2013-05-12 18:13 ` Glauber Costa
-1 siblings, 0 replies; 151+ messages in thread
From: Glauber Costa @ 2013-05-12 18:13 UTC (permalink / raw)
To: linux-mm
Cc: cgroups, Andrew Morton, Greg Thelen, kamezawa.hiroyu,
Michal Hocko, Johannes Weiner, linux-fsdevel, Dave Chinner,
Dave Chinner, Glauber Costa
From: Dave Chinner <dchinner@redhat.com>
One of the big problems with modifying the way the dcache shrinker
and LRU implementation works is that the LRU is abused in several
ways. One of these is shrink_dentry_list().
Basically, we can move a dentry off the LRU onto a different list
without doing any accounting changes, and then use dentry_lru_prune()
to remove it from what-ever list it is now on to do the LRU
accounting at that point.
This makes it -really hard- to change the LRU implementation. The
use of the per-sb LRU lock serialises movement of the dentries
between the different lists and the removal of them, and this is the
only reason that it works. If we want to break up the dentry LRU
lock and lists into, say, per-node lists, we remove the only
serialisation that allows this lru list/dispose list abuse to work.
To make this work effectively, the dispose list has to be isolated
from the LRU list - dentries have to be removed from the LRU
*before* being placed on the dispose list. This means that the LRU
accounting and isolation is completed before disposal is started,
and that means we can change the LRU implementation freely in
future.
This means that dentries *must* be marked with DCACHE_SHRINK_LIST
when they are placed on the dispose list so that we don't think that
parent dentries found in try_prune_one_dentry() are on the LRU when
the are actually on the dispose list. This would result in
accounting the dentry to the LRU a second time. Hence
dentry_lru_prune() has to handle the DCACHE_SHRINK_LIST case
differently because the dentry isn't on the LRU list.
[ v2: don't decrement nr unused twice, spotted by Sha Zhengju ]
Signed-off-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Glauber Costa <glommer@openvz.org>
Acked-by: Mel Gorman <mgorman@suse.de>
---
fs/dcache.c | 93 ++++++++++++++++++++++++++++++++++++++++++++++---------------
1 file changed, 71 insertions(+), 22 deletions(-)
diff --git a/fs/dcache.c b/fs/dcache.c
index 795c15d..868abf9 100644
--- a/fs/dcache.c
+++ b/fs/dcache.c
@@ -331,7 +331,6 @@ static void dentry_lru_add(struct dentry *dentry)
static void __dentry_lru_del(struct dentry *dentry)
{
list_del_init(&dentry->d_lru);
- dentry->d_flags &= ~DCACHE_SHRINK_LIST;
dentry->d_sb->s_nr_dentry_unused--;
this_cpu_dec(nr_dentry_unused);
}
@@ -341,6 +340,8 @@ static void __dentry_lru_del(struct dentry *dentry)
*/
static void dentry_lru_del(struct dentry *dentry)
{
+ BUG_ON(dentry->d_flags & DCACHE_SHRINK_LIST);
+
if (!list_empty(&dentry->d_lru)) {
spin_lock(&dentry->d_sb->s_dentry_lru_lock);
__dentry_lru_del(dentry);
@@ -348,15 +349,39 @@ static void dentry_lru_del(struct dentry *dentry)
}
}
+static void dentry_lru_prune(struct dentry *dentry)
+{
+ /*
+ * inform the fs via d_prune that this dentry is about to be
+ * unhashed and destroyed.
+ */
+ if (dentry->d_flags & DCACHE_OP_PRUNE)
+ dentry->d_op->d_prune(dentry);
+
+ if (list_empty(&dentry->d_lru))
+ return;
+
+ if ((dentry->d_flags & DCACHE_SHRINK_LIST)) {
+ list_del_init(&dentry->d_lru);
+ dentry->d_flags &= ~DCACHE_SHRINK_LIST;
+ } else {
+ spin_lock(&dentry->d_sb->s_dentry_lru_lock);
+ __dentry_lru_del(dentry);
+ spin_unlock(&dentry->d_sb->s_dentry_lru_lock);
+ }
+}
+
static void dentry_lru_move_list(struct dentry *dentry, struct list_head *list)
{
+ BUG_ON(dentry->d_flags & DCACHE_SHRINK_LIST);
+
spin_lock(&dentry->d_sb->s_dentry_lru_lock);
if (list_empty(&dentry->d_lru)) {
list_add_tail(&dentry->d_lru, list);
- dentry->d_sb->s_nr_dentry_unused++;
- this_cpu_inc(nr_dentry_unused);
} else {
list_move_tail(&dentry->d_lru, list);
+ dentry->d_sb->s_nr_dentry_unused--;
+ this_cpu_dec(nr_dentry_unused);
}
spin_unlock(&dentry->d_sb->s_dentry_lru_lock);
}
@@ -479,14 +504,8 @@ relock:
if (ref)
dentry->d_count--;
- /*
- * inform the fs via d_prune that this dentry is about to be
- * unhashed and destroyed.
- */
- if (dentry->d_flags & DCACHE_OP_PRUNE)
- dentry->d_op->d_prune(dentry);
- dentry_lru_del(dentry);
+ dentry_lru_prune(dentry);
/* if it was on the hash then remove it */
__d_drop(dentry);
return d_kill(dentry, parent);
@@ -800,12 +819,18 @@ static void shrink_dentry_list(struct list_head *list)
}
/*
+ * The dispose list is isolated and dentries are not accounted
+ * to the LRU here, so we can simply remove it from the list
+ * here regardless of whether it is referenced or not.
+ */
+ list_del_init(&dentry->d_lru);
+
+ /*
* We found an inuse dentry which was not removed from
- * the LRU because of laziness during lookup. Do not free
- * it - just keep it off the LRU list.
+ * the LRU because of laziness during lookup. Do not free it.
*/
if (dentry->d_count) {
- dentry_lru_del(dentry);
+ dentry->d_flags &= ~DCACHE_SHRINK_LIST;
spin_unlock(&dentry->d_lock);
continue;
}
@@ -857,6 +882,8 @@ relock:
} else {
list_move_tail(&dentry->d_lru, &tmp);
dentry->d_flags |= DCACHE_SHRINK_LIST;
+ this_cpu_dec(nr_dentry_unused);
+ sb->s_nr_dentry_unused--;
spin_unlock(&dentry->d_lock);
if (!--count)
break;
@@ -870,6 +897,27 @@ relock:
shrink_dentry_list(&tmp);
}
+/*
+ * Mark all the dentries as on being the dispose list so we don't think they are
+ * still on the LRU if we try to kill them from ascending the parent chain in
+ * try_prune_one_dentry() rather than directly from the dispose list.
+ */
+static void
+shrink_dcache_list(
+ struct list_head *dispose)
+{
+ struct dentry *dentry;
+
+ rcu_read_lock();
+ list_for_each_entry_rcu(dentry, dispose, d_lru) {
+ spin_lock(&dentry->d_lock);
+ dentry->d_flags |= DCACHE_SHRINK_LIST;
+ spin_unlock(&dentry->d_lock);
+ }
+ rcu_read_unlock();
+ shrink_dentry_list(dispose);
+}
+
/**
* shrink_dcache_sb - shrink dcache for a superblock
* @sb: superblock
@@ -884,8 +932,16 @@ void shrink_dcache_sb(struct super_block *sb)
spin_lock(&sb->s_dentry_lru_lock);
while (!list_empty(&sb->s_dentry_lru)) {
list_splice_init(&sb->s_dentry_lru, &tmp);
+
+ /*
+ * account for removal here so we don't need to handle it later
+ * even though the dentry is no longer on the lru list.
+ */
+ this_cpu_sub(nr_dentry_unused, sb->s_nr_dentry_unused);
+ sb->s_nr_dentry_unused = 0;
+
spin_unlock(&sb->s_dentry_lru_lock);
- shrink_dentry_list(&tmp);
+ shrink_dcache_list(&tmp);
spin_lock(&sb->s_dentry_lru_lock);
}
spin_unlock(&sb->s_dentry_lru_lock);
@@ -914,14 +970,7 @@ static void shrink_dcache_for_umount_subtree(struct dentry *dentry)
do {
struct inode *inode;
- /*
- * inform the fs that this dentry is about to be
- * unhashed and destroyed.
- */
- if (dentry->d_flags & DCACHE_OP_PRUNE)
- dentry->d_op->d_prune(dentry);
-
- dentry_lru_del(dentry);
+ dentry_lru_prune(dentry);
__d_shrink(dentry);
if (dentry->d_count != 0) {
--
1.8.1.4
^ permalink raw reply related [flat|nested] 151+ messages in thread* [PATCH v6 04/31] dcache: remove dentries from LRU before putting on dispose list
@ 2013-05-12 18:13 ` Glauber Costa
0 siblings, 0 replies; 151+ messages in thread
From: Glauber Costa @ 2013-05-12 18:13 UTC (permalink / raw)
To: linux-mm
Cc: cgroups, Andrew Morton, Greg Thelen, kamezawa.hiroyu,
Michal Hocko, Johannes Weiner, linux-fsdevel, Dave Chinner,
Dave Chinner, Glauber Costa
From: Dave Chinner <dchinner@redhat.com>
One of the big problems with modifying the way the dcache shrinker
and LRU implementation works is that the LRU is abused in several
ways. One of these is shrink_dentry_list().
Basically, we can move a dentry off the LRU onto a different list
without doing any accounting changes, and then use dentry_lru_prune()
to remove it from what-ever list it is now on to do the LRU
accounting at that point.
This makes it -really hard- to change the LRU implementation. The
use of the per-sb LRU lock serialises movement of the dentries
between the different lists and the removal of them, and this is the
only reason that it works. If we want to break up the dentry LRU
lock and lists into, say, per-node lists, we remove the only
serialisation that allows this lru list/dispose list abuse to work.
To make this work effectively, the dispose list has to be isolated
from the LRU list - dentries have to be removed from the LRU
*before* being placed on the dispose list. This means that the LRU
accounting and isolation is completed before disposal is started,
and that means we can change the LRU implementation freely in
future.
This means that dentries *must* be marked with DCACHE_SHRINK_LIST
when they are placed on the dispose list so that we don't think that
parent dentries found in try_prune_one_dentry() are on the LRU when
the are actually on the dispose list. This would result in
accounting the dentry to the LRU a second time. Hence
dentry_lru_prune() has to handle the DCACHE_SHRINK_LIST case
differently because the dentry isn't on the LRU list.
[ v2: don't decrement nr unused twice, spotted by Sha Zhengju ]
Signed-off-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Glauber Costa <glommer@openvz.org>
Acked-by: Mel Gorman <mgorman@suse.de>
---
fs/dcache.c | 93 ++++++++++++++++++++++++++++++++++++++++++++++---------------
1 file changed, 71 insertions(+), 22 deletions(-)
diff --git a/fs/dcache.c b/fs/dcache.c
index 795c15d..868abf9 100644
--- a/fs/dcache.c
+++ b/fs/dcache.c
@@ -331,7 +331,6 @@ static void dentry_lru_add(struct dentry *dentry)
static void __dentry_lru_del(struct dentry *dentry)
{
list_del_init(&dentry->d_lru);
- dentry->d_flags &= ~DCACHE_SHRINK_LIST;
dentry->d_sb->s_nr_dentry_unused--;
this_cpu_dec(nr_dentry_unused);
}
@@ -341,6 +340,8 @@ static void __dentry_lru_del(struct dentry *dentry)
*/
static void dentry_lru_del(struct dentry *dentry)
{
+ BUG_ON(dentry->d_flags & DCACHE_SHRINK_LIST);
+
if (!list_empty(&dentry->d_lru)) {
spin_lock(&dentry->d_sb->s_dentry_lru_lock);
__dentry_lru_del(dentry);
@@ -348,15 +349,39 @@ static void dentry_lru_del(struct dentry *dentry)
}
}
+static void dentry_lru_prune(struct dentry *dentry)
+{
+ /*
+ * inform the fs via d_prune that this dentry is about to be
+ * unhashed and destroyed.
+ */
+ if (dentry->d_flags & DCACHE_OP_PRUNE)
+ dentry->d_op->d_prune(dentry);
+
+ if (list_empty(&dentry->d_lru))
+ return;
+
+ if ((dentry->d_flags & DCACHE_SHRINK_LIST)) {
+ list_del_init(&dentry->d_lru);
+ dentry->d_flags &= ~DCACHE_SHRINK_LIST;
+ } else {
+ spin_lock(&dentry->d_sb->s_dentry_lru_lock);
+ __dentry_lru_del(dentry);
+ spin_unlock(&dentry->d_sb->s_dentry_lru_lock);
+ }
+}
+
static void dentry_lru_move_list(struct dentry *dentry, struct list_head *list)
{
+ BUG_ON(dentry->d_flags & DCACHE_SHRINK_LIST);
+
spin_lock(&dentry->d_sb->s_dentry_lru_lock);
if (list_empty(&dentry->d_lru)) {
list_add_tail(&dentry->d_lru, list);
- dentry->d_sb->s_nr_dentry_unused++;
- this_cpu_inc(nr_dentry_unused);
} else {
list_move_tail(&dentry->d_lru, list);
+ dentry->d_sb->s_nr_dentry_unused--;
+ this_cpu_dec(nr_dentry_unused);
}
spin_unlock(&dentry->d_sb->s_dentry_lru_lock);
}
@@ -479,14 +504,8 @@ relock:
if (ref)
dentry->d_count--;
- /*
- * inform the fs via d_prune that this dentry is about to be
- * unhashed and destroyed.
- */
- if (dentry->d_flags & DCACHE_OP_PRUNE)
- dentry->d_op->d_prune(dentry);
- dentry_lru_del(dentry);
+ dentry_lru_prune(dentry);
/* if it was on the hash then remove it */
__d_drop(dentry);
return d_kill(dentry, parent);
@@ -800,12 +819,18 @@ static void shrink_dentry_list(struct list_head *list)
}
/*
+ * The dispose list is isolated and dentries are not accounted
+ * to the LRU here, so we can simply remove it from the list
+ * here regardless of whether it is referenced or not.
+ */
+ list_del_init(&dentry->d_lru);
+
+ /*
* We found an inuse dentry which was not removed from
- * the LRU because of laziness during lookup. Do not free
- * it - just keep it off the LRU list.
+ * the LRU because of laziness during lookup. Do not free it.
*/
if (dentry->d_count) {
- dentry_lru_del(dentry);
+ dentry->d_flags &= ~DCACHE_SHRINK_LIST;
spin_unlock(&dentry->d_lock);
continue;
}
@@ -857,6 +882,8 @@ relock:
} else {
list_move_tail(&dentry->d_lru, &tmp);
dentry->d_flags |= DCACHE_SHRINK_LIST;
+ this_cpu_dec(nr_dentry_unused);
+ sb->s_nr_dentry_unused--;
spin_unlock(&dentry->d_lock);
if (!--count)
break;
@@ -870,6 +897,27 @@ relock:
shrink_dentry_list(&tmp);
}
+/*
+ * Mark all the dentries as on being the dispose list so we don't think they are
+ * still on the LRU if we try to kill them from ascending the parent chain in
+ * try_prune_one_dentry() rather than directly from the dispose list.
+ */
+static void
+shrink_dcache_list(
+ struct list_head *dispose)
+{
+ struct dentry *dentry;
+
+ rcu_read_lock();
+ list_for_each_entry_rcu(dentry, dispose, d_lru) {
+ spin_lock(&dentry->d_lock);
+ dentry->d_flags |= DCACHE_SHRINK_LIST;
+ spin_unlock(&dentry->d_lock);
+ }
+ rcu_read_unlock();
+ shrink_dentry_list(dispose);
+}
+
/**
* shrink_dcache_sb - shrink dcache for a superblock
* @sb: superblock
@@ -884,8 +932,16 @@ void shrink_dcache_sb(struct super_block *sb)
spin_lock(&sb->s_dentry_lru_lock);
while (!list_empty(&sb->s_dentry_lru)) {
list_splice_init(&sb->s_dentry_lru, &tmp);
+
+ /*
+ * account for removal here so we don't need to handle it later
+ * even though the dentry is no longer on the lru list.
+ */
+ this_cpu_sub(nr_dentry_unused, sb->s_nr_dentry_unused);
+ sb->s_nr_dentry_unused = 0;
+
spin_unlock(&sb->s_dentry_lru_lock);
- shrink_dentry_list(&tmp);
+ shrink_dcache_list(&tmp);
spin_lock(&sb->s_dentry_lru_lock);
}
spin_unlock(&sb->s_dentry_lru_lock);
@@ -914,14 +970,7 @@ static void shrink_dcache_for_umount_subtree(struct dentry *dentry)
do {
struct inode *inode;
- /*
- * inform the fs that this dentry is about to be
- * unhashed and destroyed.
- */
- if (dentry->d_flags & DCACHE_OP_PRUNE)
- dentry->d_op->d_prune(dentry);
-
- dentry_lru_del(dentry);
+ dentry_lru_prune(dentry);
__d_shrink(dentry);
if (dentry->d_count != 0) {
--
1.8.1.4
^ permalink raw reply related [flat|nested] 151+ messages in thread* [PATCH v6 04/31] dcache: remove dentries from LRU before putting on dispose list
@ 2013-05-12 18:13 ` Glauber Costa
0 siblings, 0 replies; 151+ messages in thread
From: Glauber Costa @ 2013-05-12 18:13 UTC (permalink / raw)
To: linux-mm
Cc: cgroups, Andrew Morton, Greg Thelen, kamezawa.hiroyu,
Michal Hocko, Johannes Weiner, linux-fsdevel, Dave Chinner,
Dave Chinner, Glauber Costa
From: Dave Chinner <dchinner@redhat.com>
One of the big problems with modifying the way the dcache shrinker
and LRU implementation works is that the LRU is abused in several
ways. One of these is shrink_dentry_list().
Basically, we can move a dentry off the LRU onto a different list
without doing any accounting changes, and then use dentry_lru_prune()
to remove it from what-ever list it is now on to do the LRU
accounting at that point.
This makes it -really hard- to change the LRU implementation. The
use of the per-sb LRU lock serialises movement of the dentries
between the different lists and the removal of them, and this is the
only reason that it works. If we want to break up the dentry LRU
lock and lists into, say, per-node lists, we remove the only
serialisation that allows this lru list/dispose list abuse to work.
To make this work effectively, the dispose list has to be isolated
from the LRU list - dentries have to be removed from the LRU
*before* being placed on the dispose list. This means that the LRU
accounting and isolation is completed before disposal is started,
and that means we can change the LRU implementation freely in
future.
This means that dentries *must* be marked with DCACHE_SHRINK_LIST
when they are placed on the dispose list so that we don't think that
parent dentries found in try_prune_one_dentry() are on the LRU when
the are actually on the dispose list. This would result in
accounting the dentry to the LRU a second time. Hence
dentry_lru_prune() has to handle the DCACHE_SHRINK_LIST case
differently because the dentry isn't on the LRU list.
[ v2: don't decrement nr unused twice, spotted by Sha Zhengju ]
Signed-off-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Glauber Costa <glommer@openvz.org>
Acked-by: Mel Gorman <mgorman@suse.de>
---
fs/dcache.c | 93 ++++++++++++++++++++++++++++++++++++++++++++++---------------
1 file changed, 71 insertions(+), 22 deletions(-)
diff --git a/fs/dcache.c b/fs/dcache.c
index 795c15d..868abf9 100644
--- a/fs/dcache.c
+++ b/fs/dcache.c
@@ -331,7 +331,6 @@ static void dentry_lru_add(struct dentry *dentry)
static void __dentry_lru_del(struct dentry *dentry)
{
list_del_init(&dentry->d_lru);
- dentry->d_flags &= ~DCACHE_SHRINK_LIST;
dentry->d_sb->s_nr_dentry_unused--;
this_cpu_dec(nr_dentry_unused);
}
@@ -341,6 +340,8 @@ static void __dentry_lru_del(struct dentry *dentry)
*/
static void dentry_lru_del(struct dentry *dentry)
{
+ BUG_ON(dentry->d_flags & DCACHE_SHRINK_LIST);
+
if (!list_empty(&dentry->d_lru)) {
spin_lock(&dentry->d_sb->s_dentry_lru_lock);
__dentry_lru_del(dentry);
@@ -348,15 +349,39 @@ static void dentry_lru_del(struct dentry *dentry)
}
}
+static void dentry_lru_prune(struct dentry *dentry)
+{
+ /*
+ * inform the fs via d_prune that this dentry is about to be
+ * unhashed and destroyed.
+ */
+ if (dentry->d_flags & DCACHE_OP_PRUNE)
+ dentry->d_op->d_prune(dentry);
+
+ if (list_empty(&dentry->d_lru))
+ return;
+
+ if ((dentry->d_flags & DCACHE_SHRINK_LIST)) {
+ list_del_init(&dentry->d_lru);
+ dentry->d_flags &= ~DCACHE_SHRINK_LIST;
+ } else {
+ spin_lock(&dentry->d_sb->s_dentry_lru_lock);
+ __dentry_lru_del(dentry);
+ spin_unlock(&dentry->d_sb->s_dentry_lru_lock);
+ }
+}
+
static void dentry_lru_move_list(struct dentry *dentry, struct list_head *list)
{
+ BUG_ON(dentry->d_flags & DCACHE_SHRINK_LIST);
+
spin_lock(&dentry->d_sb->s_dentry_lru_lock);
if (list_empty(&dentry->d_lru)) {
list_add_tail(&dentry->d_lru, list);
- dentry->d_sb->s_nr_dentry_unused++;
- this_cpu_inc(nr_dentry_unused);
} else {
list_move_tail(&dentry->d_lru, list);
+ dentry->d_sb->s_nr_dentry_unused--;
+ this_cpu_dec(nr_dentry_unused);
}
spin_unlock(&dentry->d_sb->s_dentry_lru_lock);
}
@@ -479,14 +504,8 @@ relock:
if (ref)
dentry->d_count--;
- /*
- * inform the fs via d_prune that this dentry is about to be
- * unhashed and destroyed.
- */
- if (dentry->d_flags & DCACHE_OP_PRUNE)
- dentry->d_op->d_prune(dentry);
- dentry_lru_del(dentry);
+ dentry_lru_prune(dentry);
/* if it was on the hash then remove it */
__d_drop(dentry);
return d_kill(dentry, parent);
@@ -800,12 +819,18 @@ static void shrink_dentry_list(struct list_head *list)
}
/*
+ * The dispose list is isolated and dentries are not accounted
+ * to the LRU here, so we can simply remove it from the list
+ * here regardless of whether it is referenced or not.
+ */
+ list_del_init(&dentry->d_lru);
+
+ /*
* We found an inuse dentry which was not removed from
- * the LRU because of laziness during lookup. Do not free
- * it - just keep it off the LRU list.
+ * the LRU because of laziness during lookup. Do not free it.
*/
if (dentry->d_count) {
- dentry_lru_del(dentry);
+ dentry->d_flags &= ~DCACHE_SHRINK_LIST;
spin_unlock(&dentry->d_lock);
continue;
}
@@ -857,6 +882,8 @@ relock:
} else {
list_move_tail(&dentry->d_lru, &tmp);
dentry->d_flags |= DCACHE_SHRINK_LIST;
+ this_cpu_dec(nr_dentry_unused);
+ sb->s_nr_dentry_unused--;
spin_unlock(&dentry->d_lock);
if (!--count)
break;
@@ -870,6 +897,27 @@ relock:
shrink_dentry_list(&tmp);
}
+/*
+ * Mark all the dentries as on being the dispose list so we don't think they are
+ * still on the LRU if we try to kill them from ascending the parent chain in
+ * try_prune_one_dentry() rather than directly from the dispose list.
+ */
+static void
+shrink_dcache_list(
+ struct list_head *dispose)
+{
+ struct dentry *dentry;
+
+ rcu_read_lock();
+ list_for_each_entry_rcu(dentry, dispose, d_lru) {
+ spin_lock(&dentry->d_lock);
+ dentry->d_flags |= DCACHE_SHRINK_LIST;
+ spin_unlock(&dentry->d_lock);
+ }
+ rcu_read_unlock();
+ shrink_dentry_list(dispose);
+}
+
/**
* shrink_dcache_sb - shrink dcache for a superblock
* @sb: superblock
@@ -884,8 +932,16 @@ void shrink_dcache_sb(struct super_block *sb)
spin_lock(&sb->s_dentry_lru_lock);
while (!list_empty(&sb->s_dentry_lru)) {
list_splice_init(&sb->s_dentry_lru, &tmp);
+
+ /*
+ * account for removal here so we don't need to handle it later
+ * even though the dentry is no longer on the lru list.
+ */
+ this_cpu_sub(nr_dentry_unused, sb->s_nr_dentry_unused);
+ sb->s_nr_dentry_unused = 0;
+
spin_unlock(&sb->s_dentry_lru_lock);
- shrink_dentry_list(&tmp);
+ shrink_dcache_list(&tmp);
spin_lock(&sb->s_dentry_lru_lock);
}
spin_unlock(&sb->s_dentry_lru_lock);
@@ -914,14 +970,7 @@ static void shrink_dcache_for_umount_subtree(struct dentry *dentry)
do {
struct inode *inode;
- /*
- * inform the fs that this dentry is about to be
- * unhashed and destroyed.
- */
- if (dentry->d_flags & DCACHE_OP_PRUNE)
- dentry->d_op->d_prune(dentry);
-
- dentry_lru_del(dentry);
+ dentry_lru_prune(dentry);
__d_shrink(dentry);
if (dentry->d_count != 0) {
--
1.8.1.4
--
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^ permalink raw reply related [flat|nested] 151+ messages in thread* Re: [PATCH v6 04/31] dcache: remove dentries from LRU before putting on dispose list
2013-05-12 18:13 ` Glauber Costa
(?)
(?)
@ 2013-05-14 2:02 ` Dave Chinner
-1 siblings, 0 replies; 151+ messages in thread
From: Dave Chinner @ 2013-05-14 2:02 UTC (permalink / raw)
To: Glauber Costa
Cc: linux-mm, cgroups, Andrew Morton, Greg Thelen, kamezawa.hiroyu,
Michal Hocko, Johannes Weiner, linux-fsdevel, Dave Chinner
On Sun, May 12, 2013 at 10:13:25PM +0400, Glauber Costa wrote:
> From: Dave Chinner <dchinner@redhat.com>
>
> One of the big problems with modifying the way the dcache shrinker
> and LRU implementation works is that the LRU is abused in several
> ways. One of these is shrink_dentry_list().
>
> Basically, we can move a dentry off the LRU onto a different list
> without doing any accounting changes, and then use dentry_lru_prune()
> to remove it from what-ever list it is now on to do the LRU
> accounting at that point.
>
> This makes it -really hard- to change the LRU implementation. The
> use of the per-sb LRU lock serialises movement of the dentries
> between the different lists and the removal of them, and this is the
> only reason that it works. If we want to break up the dentry LRU
> lock and lists into, say, per-node lists, we remove the only
> serialisation that allows this lru list/dispose list abuse to work.
>
> To make this work effectively, the dispose list has to be isolated
> from the LRU list - dentries have to be removed from the LRU
> *before* being placed on the dispose list. This means that the LRU
> accounting and isolation is completed before disposal is started,
> and that means we can change the LRU implementation freely in
> future.
>
> This means that dentries *must* be marked with DCACHE_SHRINK_LIST
> when they are placed on the dispose list so that we don't think that
> parent dentries found in try_prune_one_dentry() are on the LRU when
> the are actually on the dispose list. This would result in
> accounting the dentry to the LRU a second time. Hence
> dentry_lru_prune() has to handle the DCACHE_SHRINK_LIST case
> differently because the dentry isn't on the LRU list.
>
> [ v2: don't decrement nr unused twice, spotted by Sha Zhengju ]
> Signed-off-by: Dave Chinner <dchinner@redhat.com>
> Signed-off-by: Glauber Costa <glommer@openvz.org>
> Acked-by: Mel Gorman <mgorman@suse.de>
> ---
> fs/dcache.c | 93 ++++++++++++++++++++++++++++++++++++++++++++++---------------
> 1 file changed, 71 insertions(+), 22 deletions(-)
>
> diff --git a/fs/dcache.c b/fs/dcache.c
> index 795c15d..868abf9 100644
> --- a/fs/dcache.c
> +++ b/fs/dcache.c
> @@ -331,7 +331,6 @@ static void dentry_lru_add(struct dentry *dentry)
> static void __dentry_lru_del(struct dentry *dentry)
> {
> list_del_init(&dentry->d_lru);
> - dentry->d_flags &= ~DCACHE_SHRINK_LIST;
> dentry->d_sb->s_nr_dentry_unused--;
> this_cpu_dec(nr_dentry_unused);
> }
> @@ -341,6 +340,8 @@ static void __dentry_lru_del(struct dentry *dentry)
> */
> static void dentry_lru_del(struct dentry *dentry)
> {
> + BUG_ON(dentry->d_flags & DCACHE_SHRINK_LIST);
> +
> if (!list_empty(&dentry->d_lru)) {
> spin_lock(&dentry->d_sb->s_dentry_lru_lock);
> __dentry_lru_del(dentry);
> @@ -348,15 +349,39 @@ static void dentry_lru_del(struct dentry *dentry)
> }
> }
>
> +static void dentry_lru_prune(struct dentry *dentry)
> +{
> + /*
> + * inform the fs via d_prune that this dentry is about to be
> + * unhashed and destroyed.
> + */
> + if (dentry->d_flags & DCACHE_OP_PRUNE)
> + dentry->d_op->d_prune(dentry);
> +
> + if (list_empty(&dentry->d_lru))
> + return;
> +
> + if ((dentry->d_flags & DCACHE_SHRINK_LIST)) {
> + list_del_init(&dentry->d_lru);
> + dentry->d_flags &= ~DCACHE_SHRINK_LIST;
> + } else {
> + spin_lock(&dentry->d_sb->s_dentry_lru_lock);
> + __dentry_lru_del(dentry);
> + spin_unlock(&dentry->d_sb->s_dentry_lru_lock);
> + }
> +}
Re-adding this function is wrong - it went away because the act of
calling ->d_prune is independent of the presence of the dentry on
the LRU.
> @@ -479,14 +504,8 @@ relock:
>
> if (ref)
> dentry->d_count--;
> - /*
> - * inform the fs via d_prune that this dentry is about to be
> - * unhashed and destroyed.
> - */
> - if (dentry->d_flags & DCACHE_OP_PRUNE)
> - dentry->d_op->d_prune(dentry);
>
> - dentry_lru_del(dentry);
> + dentry_lru_prune(dentry);
> /* if it was on the hash then remove it */
> __d_drop(dentry);
> return d_kill(dentry, parent);
So this change is not necessary.
> @@ -914,14 +970,7 @@ static void shrink_dcache_for_umount_subtree(struct dentry *dentry)
> do {
> struct inode *inode;
>
> - /*
> - * inform the fs that this dentry is about to be
> - * unhashed and destroyed.
> - */
> - if (dentry->d_flags & DCACHE_OP_PRUNE)
> - dentry->d_op->d_prune(dentry);
> -
> - dentry_lru_del(dentry);
> + dentry_lru_prune(dentry);
> __d_shrink(dentry);
>
> if (dentry->d_count != 0) {
Nor is this one.
Cheers,
Dave.
--
Dave Chinner
david@fromorbit.com
--
To unsubscribe, send a message with 'unsubscribe linux-mm' in
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^ permalink raw reply [flat|nested] 151+ messages in thread* [PATCH v7 04/31] dcache: remove dentries from LRU before putting on dispose list
2013-05-12 18:13 ` Glauber Costa
` (2 preceding siblings ...)
(?)
@ 2013-05-14 5:46 ` Dave Chinner
2013-05-14 7:10 ` Dave Chinner
2013-05-14 12:43 ` Glauber Costa
-1 siblings, 2 replies; 151+ messages in thread
From: Dave Chinner @ 2013-05-14 5:46 UTC (permalink / raw)
To: Glauber Costa
Cc: linux-mm, cgroups, Andrew Morton, Greg Thelen, kamezawa.hiroyu,
Michal Hocko, Johannes Weiner, linux-fsdevel, Dave Chinner
From: Dave Chinner <dchinner@redhat.com>
One of the big problems with modifying the way the dcache shrinker
and LRU implementation works is that the LRU is abused in several
ways. One of these is shrink_dentry_list().
Basically, we can move a dentry off the LRU onto a different list
without doing any accounting changes, and then use dentry_lru_prune()
to remove it from what-ever list it is now on to do the LRU
accounting at that point.
This makes it -really hard- to change the LRU implementation. The
use of the per-sb LRU lock serialises movement of the dentries
between the different lists and the removal of them, and this is the
only reason that it works. If we want to break up the dentry LRU
lock and lists into, say, per-node lists, we remove the only
serialisation that allows this lru list/dispose list abuse to work.
To make this work effectively, the dispose list has to be isolated
from the LRU list - dentries have to be removed from the LRU
*before* being placed on the dispose list. This means that the LRU
accounting and isolation is completed before disposal is started,
and that means we can change the LRU implementation freely in
future.
This means that dentries *must* be marked with DCACHE_SHRINK_LIST
when they are placed on the dispose list so that we don't think that
parent dentries found in try_prune_one_dentry() are on the LRU when
the are actually on the dispose list. This would result in
accounting the dentry to the LRU a second time. Hence
dentry_lru_del() has to handle the DCACHE_SHRINK_LIST case
differently because the dentry isn't on the LRU list.
[ v2: don't decrement nr unused twice, spotted by Sha Zhengju ]
[ v7: (dchinner)
- shrink list leaks dentries when inode/parent can't be locked in
dentry_kill().
- fix the scope of the sb locking inside shrink_dcache_sb()
- remove the readdition of dentry_lru_prune(). ]
Signed-off-by: Dave Chinner <dchinner@redhat.com>
---
fs/dcache.c | 91 ++++++++++++++++++++++++++++++++++++++++++++---------------
1 file changed, 69 insertions(+), 22 deletions(-)
diff --git a/fs/dcache.c b/fs/dcache.c
index 795c15d..df37740 100644
--- a/fs/dcache.c
+++ b/fs/dcache.c
@@ -315,7 +315,7 @@ static void dentry_unlink_inode(struct dentry * dentry)
}
/*
- * dentry_lru_(add|del|prune|move_tail) must be called with d_lock held.
+ * dentry_lru_(add|del|move_list) must be called with d_lock held.
*/
static void dentry_lru_add(struct dentry *dentry)
{
@@ -341,7 +341,8 @@ static void __dentry_lru_del(struct dentry *dentry)
*/
static void dentry_lru_del(struct dentry *dentry)
{
- if (!list_empty(&dentry->d_lru)) {
+ if (!list_empty(&dentry->d_lru) &&
+ !(dentry->d_flags & DCACHE_SHRINK_LIST)) {
spin_lock(&dentry->d_sb->s_dentry_lru_lock);
__dentry_lru_del(dentry);
spin_unlock(&dentry->d_sb->s_dentry_lru_lock);
@@ -350,13 +351,15 @@ static void dentry_lru_del(struct dentry *dentry)
static void dentry_lru_move_list(struct dentry *dentry, struct list_head *list)
{
+ BUG_ON(dentry->d_flags & DCACHE_SHRINK_LIST);
+
spin_lock(&dentry->d_sb->s_dentry_lru_lock);
if (list_empty(&dentry->d_lru)) {
list_add_tail(&dentry->d_lru, list);
- dentry->d_sb->s_nr_dentry_unused++;
- this_cpu_inc(nr_dentry_unused);
} else {
list_move_tail(&dentry->d_lru, list);
+ dentry->d_sb->s_nr_dentry_unused--;
+ this_cpu_dec(nr_dentry_unused);
}
spin_unlock(&dentry->d_sb->s_dentry_lru_lock);
}
@@ -454,7 +457,8 @@ EXPORT_SYMBOL(d_drop);
* If ref is non-zero, then decrement the refcount too.
* Returns dentry requiring refcount drop, or NULL if we're done.
*/
-static inline struct dentry *dentry_kill(struct dentry *dentry, int ref)
+static inline struct dentry *
+dentry_kill(struct dentry *dentry, int ref, int unlock_on_failure)
__releases(dentry->d_lock)
{
struct inode *inode;
@@ -463,8 +467,10 @@ static inline struct dentry *dentry_kill(struct dentry *dentry, int ref)
inode = dentry->d_inode;
if (inode && !spin_trylock(&inode->i_lock)) {
relock:
- spin_unlock(&dentry->d_lock);
- cpu_relax();
+ if (unlock_on_failure) {
+ spin_unlock(&dentry->d_lock);
+ cpu_relax();
+ }
return dentry; /* try again with same dentry */
}
if (IS_ROOT(dentry))
@@ -551,7 +557,7 @@ repeat:
return;
kill_it:
- dentry = dentry_kill(dentry, 1);
+ dentry = dentry_kill(dentry, 1, 1);
if (dentry)
goto repeat;
}
@@ -750,12 +756,12 @@ EXPORT_SYMBOL(d_prune_aliases);
*
* This may fail if locks cannot be acquired no problem, just try again.
*/
-static void try_prune_one_dentry(struct dentry *dentry)
+static struct dentry * try_prune_one_dentry(struct dentry *dentry)
__releases(dentry->d_lock)
{
struct dentry *parent;
- parent = dentry_kill(dentry, 0);
+ parent = dentry_kill(dentry, 0, 0);
/*
* If dentry_kill returns NULL, we have nothing more to do.
* if it returns the same dentry, trylocks failed. In either
@@ -767,9 +773,9 @@ static void try_prune_one_dentry(struct dentry *dentry)
* fragmentation.
*/
if (!parent)
- return;
+ return NULL;
if (parent == dentry)
- return;
+ return dentry;
/* Prune ancestors. */
dentry = parent;
@@ -778,10 +784,11 @@ static void try_prune_one_dentry(struct dentry *dentry)
if (dentry->d_count > 1) {
dentry->d_count--;
spin_unlock(&dentry->d_lock);
- return;
+ return NULL;
}
- dentry = dentry_kill(dentry, 1);
+ dentry = dentry_kill(dentry, 1, 1);
}
+ return NULL;
}
static void shrink_dentry_list(struct list_head *list)
@@ -800,21 +807,31 @@ static void shrink_dentry_list(struct list_head *list)
}
/*
+ * The dispose list is isolated and dentries are not accounted
+ * to the LRU here, so we can simply remove it from the list
+ * here regardless of whether it is referenced or not.
+ */
+ list_del_init(&dentry->d_lru);
+ dentry->d_flags &= ~DCACHE_SHRINK_LIST;
+
+ /*
* We found an inuse dentry which was not removed from
- * the LRU because of laziness during lookup. Do not free
- * it - just keep it off the LRU list.
+ * the LRU because of laziness during lookup. Do not free it.
*/
if (dentry->d_count) {
- dentry_lru_del(dentry);
spin_unlock(&dentry->d_lock);
continue;
}
-
rcu_read_unlock();
- try_prune_one_dentry(dentry);
+ dentry = try_prune_one_dentry(dentry);
rcu_read_lock();
+ if (dentry) {
+ dentry->d_flags |= DCACHE_SHRINK_LIST;
+ list_add(&dentry->d_lru, list);
+ spin_unlock(&dentry->d_lock);
+ }
}
rcu_read_unlock();
}
@@ -855,8 +872,10 @@ relock:
list_move(&dentry->d_lru, &referenced);
spin_unlock(&dentry->d_lock);
} else {
- list_move_tail(&dentry->d_lru, &tmp);
+ list_move(&dentry->d_lru, &tmp);
dentry->d_flags |= DCACHE_SHRINK_LIST;
+ this_cpu_dec(nr_dentry_unused);
+ sb->s_nr_dentry_unused--;
spin_unlock(&dentry->d_lock);
if (!--count)
break;
@@ -870,6 +889,27 @@ relock:
shrink_dentry_list(&tmp);
}
+/*
+ * Mark all the dentries as on being the dispose list so we don't think they are
+ * still on the LRU if we try to kill them from ascending the parent chain in
+ * try_prune_one_dentry() rather than directly from the dispose list.
+ */
+static void
+shrink_dcache_list(
+ struct list_head *dispose)
+{
+ struct dentry *dentry;
+
+ rcu_read_lock();
+ list_for_each_entry_rcu(dentry, dispose, d_lru) {
+ spin_lock(&dentry->d_lock);
+ dentry->d_flags |= DCACHE_SHRINK_LIST;
+ spin_unlock(&dentry->d_lock);
+ }
+ rcu_read_unlock();
+ shrink_dentry_list(dispose);
+}
+
/**
* shrink_dcache_sb - shrink dcache for a superblock
* @sb: superblock
@@ -883,9 +923,16 @@ void shrink_dcache_sb(struct super_block *sb)
spin_lock(&sb->s_dentry_lru_lock);
while (!list_empty(&sb->s_dentry_lru)) {
- list_splice_init(&sb->s_dentry_lru, &tmp);
+ /*
+ * account for removal here so we don't need to handle it later
+ * even though the dentry is no longer on the lru list.
+ */
spin_unlock(&sb->s_dentry_lru_lock);
- shrink_dentry_list(&tmp);
+ list_splice_init(&sb->s_dentry_lru, &tmp);
+ this_cpu_sub(nr_dentry_unused, sb->s_nr_dentry_unused);
+ sb->s_nr_dentry_unused = 0;
+
+ shrink_dcache_list(&tmp);
spin_lock(&sb->s_dentry_lru_lock);
}
spin_unlock(&sb->s_dentry_lru_lock);
--
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^ permalink raw reply related [flat|nested] 151+ messages in thread* Re: [PATCH v7 04/31] dcache: remove dentries from LRU before putting on dispose list
2013-05-14 5:46 ` [PATCH v7 " Dave Chinner
@ 2013-05-14 7:10 ` Dave Chinner
2013-05-14 12:43 ` Glauber Costa
1 sibling, 0 replies; 151+ messages in thread
From: Dave Chinner @ 2013-05-14 7:10 UTC (permalink / raw)
To: Glauber Costa
Cc: linux-mm, cgroups, Andrew Morton, Greg Thelen, kamezawa.hiroyu,
Michal Hocko, Johannes Weiner, linux-fsdevel, Dave Chinner
On Tue, May 14, 2013 at 03:46:40PM +1000, Dave Chinner wrote:
> From: Dave Chinner <dchinner@redhat.com>
>
> One of the big problems with modifying the way the dcache shrinker
> and LRU implementation works is that the LRU is abused in several
> ways. One of these is shrink_dentry_list().
>
> Basically, we can move a dentry off the LRU onto a different list
> without doing any accounting changes, and then use dentry_lru_prune()
> to remove it from what-ever list it is now on to do the LRU
> accounting at that point.
>
> This makes it -really hard- to change the LRU implementation. The
> use of the per-sb LRU lock serialises movement of the dentries
> between the different lists and the removal of them, and this is the
> only reason that it works. If we want to break up the dentry LRU
> lock and lists into, say, per-node lists, we remove the only
> serialisation that allows this lru list/dispose list abuse to work.
>
> To make this work effectively, the dispose list has to be isolated
> from the LRU list - dentries have to be removed from the LRU
> *before* being placed on the dispose list. This means that the LRU
> accounting and isolation is completed before disposal is started,
> and that means we can change the LRU implementation freely in
> future.
>
> This means that dentries *must* be marked with DCACHE_SHRINK_LIST
> when they are placed on the dispose list so that we don't think that
> parent dentries found in try_prune_one_dentry() are on the LRU when
> the are actually on the dispose list. This would result in
> accounting the dentry to the LRU a second time. Hence
> dentry_lru_del() has to handle the DCACHE_SHRINK_LIST case
> differently because the dentry isn't on the LRU list.
>
> [ v2: don't decrement nr unused twice, spotted by Sha Zhengju ]
> [ v7: (dchinner)
> - shrink list leaks dentries when inode/parent can't be locked in
> dentry_kill().
> - fix the scope of the sb locking inside shrink_dcache_sb()
<sigh>
I need find a dealer that sells better crack.
> @@ -883,9 +923,16 @@ void shrink_dcache_sb(struct super_block *sb)
>
> spin_lock(&sb->s_dentry_lru_lock);
> while (!list_empty(&sb->s_dentry_lru)) {
> - list_splice_init(&sb->s_dentry_lru, &tmp);
> + /*
> + * account for removal here so we don't need to handle it later
> + * even though the dentry is no longer on the lru list.
> + */
> spin_unlock(&sb->s_dentry_lru_lock);
> - shrink_dentry_list(&tmp);
> + list_splice_init(&sb->s_dentry_lru, &tmp);
> + this_cpu_sub(nr_dentry_unused, sb->s_nr_dentry_unused);
> + sb->s_nr_dentry_unused = 0;
> +
> + shrink_dcache_list(&tmp);
> spin_lock(&sb->s_dentry_lru_lock);
This is now completely wrong. It should end up like this:
while (!list_empty(&sb->s_dentry_lru)) {
/*
* account for removal here so we don't need to handle it later
* even though the dentry is no longer on the lru list.
*/
list_splice_init(&sb->s_dentry_lru, &tmp);
this_cpu_sub(nr_dentry_unused, sb->s_nr_dentry_unused);
sb->s_nr_dentry_unused = 0;
spin_unlock(&sb->s_dentry_lru_lock);
shrink_dcache_list(&tmp);
spin_lock(&sb->s_dentry_lru_lock);
}
spin_unlock(&sb->s_dentry_lru_lock);
-Dave.
--
Dave Chinner
david@fromorbit.com
--
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^ permalink raw reply [flat|nested] 151+ messages in thread* Re: [PATCH v7 04/31] dcache: remove dentries from LRU before putting on dispose list
2013-05-14 5:46 ` [PATCH v7 " Dave Chinner
2013-05-14 7:10 ` Dave Chinner
@ 2013-05-14 12:43 ` Glauber Costa
1 sibling, 0 replies; 151+ messages in thread
From: Glauber Costa @ 2013-05-14 12:43 UTC (permalink / raw)
To: Dave Chinner
Cc: Glauber Costa, linux-mm, cgroups, Andrew Morton, Greg Thelen,
kamezawa.hiroyu, Michal Hocko, Johannes Weiner, linux-fsdevel,
Dave Chinner
On 05/14/2013 09:46 AM, Dave Chinner wrote:
> [ v2: don't decrement nr unused twice, spotted by Sha Zhengju ]
> [ v7: (dchinner)
> - shrink list leaks dentries when inode/parent can't be locked in
> dentry_kill().
> - fix the scope of the sb locking inside shrink_dcache_sb()
> - remove the readdition of dentry_lru_prune(). ]
Dave,
dentry_lru_prune was removed because it would only prune the dentry if
it was in the LRU list, and it has to be always pruned (61572bb1).
You don't reintroduce dentry_lru_prune here, so the two locations which
prune dentries read as follows:
if (dentry->d_flags & DCACHE_OP_PRUNE)
dentry->d_op->d_prune(dentry);
dentry_lru_del(dentry);
I believe this is wrong. My old version would do:
+static void dentry_lru_prune(struct dentry *dentry)
+{
+ /*
+ * inform the fs via d_prune that this dentry is about to be
+ * unhashed and destroyed.
+ */
+ if (dentry->d_flags & DCACHE_OP_PRUNE)
+ dentry->d_op->d_prune(dentry);
+
+ if (list_empty(&dentry->d_lru))
+ return;
+
+ if ((dentry->d_flags & DCACHE_SHRINK_LIST)) {
+ list_del_init(&dentry->d_lru);
+ dentry->d_flags &= ~DCACHE_SHRINK_LIST;
+ } else {
+ spin_lock(&dentry->d_sb->s_dentry_lru_lock);
+ __dentry_lru_del(dentry);
+ spin_unlock(&dentry->d_sb->s_dentry_lru_lock);
+ }
+}
Which is SHRINK_LIST aware. The code as it reads today after your patch
will only be correct if it is totally impossible for a dentry to be in
the shrink list before we reach both sites that call d_op->d_prune. They
are: dentry_kill and shrink_dcache_for_umount_subtree. So it seems to me
that we do really need to reintroduce dentry_lru_prune or just patch
both call sites with shrik-list aware code.
Comments ?
^ permalink raw reply [flat|nested] 151+ messages in thread* Re: [PATCH v7 04/31] dcache: remove dentries from LRU before putting on dispose list
@ 2013-05-14 12:43 ` Glauber Costa
0 siblings, 0 replies; 151+ messages in thread
From: Glauber Costa @ 2013-05-14 12:43 UTC (permalink / raw)
To: Dave Chinner
Cc: Glauber Costa, linux-mm, cgroups, Andrew Morton, Greg Thelen,
kamezawa.hiroyu, Michal Hocko, Johannes Weiner, linux-fsdevel,
Dave Chinner
On 05/14/2013 09:46 AM, Dave Chinner wrote:
> [ v2: don't decrement nr unused twice, spotted by Sha Zhengju ]
> [ v7: (dchinner)
> - shrink list leaks dentries when inode/parent can't be locked in
> dentry_kill().
> - fix the scope of the sb locking inside shrink_dcache_sb()
> - remove the readdition of dentry_lru_prune(). ]
Dave,
dentry_lru_prune was removed because it would only prune the dentry if
it was in the LRU list, and it has to be always pruned (61572bb1).
You don't reintroduce dentry_lru_prune here, so the two locations which
prune dentries read as follows:
if (dentry->d_flags & DCACHE_OP_PRUNE)
dentry->d_op->d_prune(dentry);
dentry_lru_del(dentry);
I believe this is wrong. My old version would do:
+static void dentry_lru_prune(struct dentry *dentry)
+{
+ /*
+ * inform the fs via d_prune that this dentry is about to be
+ * unhashed and destroyed.
+ */
+ if (dentry->d_flags & DCACHE_OP_PRUNE)
+ dentry->d_op->d_prune(dentry);
+
+ if (list_empty(&dentry->d_lru))
+ return;
+
+ if ((dentry->d_flags & DCACHE_SHRINK_LIST)) {
+ list_del_init(&dentry->d_lru);
+ dentry->d_flags &= ~DCACHE_SHRINK_LIST;
+ } else {
+ spin_lock(&dentry->d_sb->s_dentry_lru_lock);
+ __dentry_lru_del(dentry);
+ spin_unlock(&dentry->d_sb->s_dentry_lru_lock);
+ }
+}
Which is SHRINK_LIST aware. The code as it reads today after your patch
will only be correct if it is totally impossible for a dentry to be in
the shrink list before we reach both sites that call d_op->d_prune. They
are: dentry_kill and shrink_dcache_for_umount_subtree. So it seems to me
that we do really need to reintroduce dentry_lru_prune or just patch
both call sites with shrik-list aware code.
Comments ?
^ permalink raw reply [flat|nested] 151+ messages in thread* Re: [PATCH v7 04/31] dcache: remove dentries from LRU before putting on dispose list
@ 2013-05-14 12:43 ` Glauber Costa
0 siblings, 0 replies; 151+ messages in thread
From: Glauber Costa @ 2013-05-14 12:43 UTC (permalink / raw)
To: Dave Chinner
Cc: Glauber Costa, linux-mm, cgroups, Andrew Morton, Greg Thelen,
kamezawa.hiroyu, Michal Hocko, Johannes Weiner, linux-fsdevel,
Dave Chinner
On 05/14/2013 09:46 AM, Dave Chinner wrote:
> [ v2: don't decrement nr unused twice, spotted by Sha Zhengju ]
> [ v7: (dchinner)
> - shrink list leaks dentries when inode/parent can't be locked in
> dentry_kill().
> - fix the scope of the sb locking inside shrink_dcache_sb()
> - remove the readdition of dentry_lru_prune(). ]
Dave,
dentry_lru_prune was removed because it would only prune the dentry if
it was in the LRU list, and it has to be always pruned (61572bb1).
You don't reintroduce dentry_lru_prune here, so the two locations which
prune dentries read as follows:
if (dentry->d_flags & DCACHE_OP_PRUNE)
dentry->d_op->d_prune(dentry);
dentry_lru_del(dentry);
I believe this is wrong. My old version would do:
+static void dentry_lru_prune(struct dentry *dentry)
+{
+ /*
+ * inform the fs via d_prune that this dentry is about to be
+ * unhashed and destroyed.
+ */
+ if (dentry->d_flags & DCACHE_OP_PRUNE)
+ dentry->d_op->d_prune(dentry);
+
+ if (list_empty(&dentry->d_lru))
+ return;
+
+ if ((dentry->d_flags & DCACHE_SHRINK_LIST)) {
+ list_del_init(&dentry->d_lru);
+ dentry->d_flags &= ~DCACHE_SHRINK_LIST;
+ } else {
+ spin_lock(&dentry->d_sb->s_dentry_lru_lock);
+ __dentry_lru_del(dentry);
+ spin_unlock(&dentry->d_sb->s_dentry_lru_lock);
+ }
+}
Which is SHRINK_LIST aware. The code as it reads today after your patch
will only be correct if it is totally impossible for a dentry to be in
the shrink list before we reach both sites that call d_op->d_prune. They
are: dentry_kill and shrink_dcache_for_umount_subtree. So it seems to me
that we do really need to reintroduce dentry_lru_prune or just patch
both call sites with shrik-list aware code.
Comments ?
--
To unsubscribe, send a message with 'unsubscribe linux-mm' in
the body to majordomo@kvack.org. For more info on Linux MM,
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^ permalink raw reply [flat|nested] 151+ messages in thread[parent not found: <51923158.7040002-bzQdu9zFT3WakBO8gow8eQ@public.gmane.org>]
* Re: [PATCH v7 04/31] dcache: remove dentries from LRU before putting on dispose list
2013-05-14 12:43 ` Glauber Costa
@ 2013-05-14 20:32 ` Dave Chinner
-1 siblings, 0 replies; 151+ messages in thread
From: Dave Chinner @ 2013-05-14 20:32 UTC (permalink / raw)
To: Glauber Costa
Cc: Glauber Costa, linux-mm-Bw31MaZKKs3YtjvyW6yDsg,
cgroups-u79uwXL29TY76Z2rM5mHXA, Andrew Morton, Greg Thelen,
kamezawa.hiroyu-+CUm20s59erQFUHtdCDX3A, Michal Hocko,
Johannes Weiner, linux-fsdevel-u79uwXL29TY76Z2rM5mHXA,
Dave Chinner
On Tue, May 14, 2013 at 04:43:04PM +0400, Glauber Costa wrote:
> On 05/14/2013 09:46 AM, Dave Chinner wrote:
> > [ v2: don't decrement nr unused twice, spotted by Sha Zhengju ]
> > [ v7: (dchinner)
> > - shrink list leaks dentries when inode/parent can't be locked in
> > dentry_kill().
> > - fix the scope of the sb locking inside shrink_dcache_sb()
> > - remove the readdition of dentry_lru_prune(). ]
>
> Dave,
>
> dentry_lru_prune was removed because it would only prune the dentry if
> it was in the LRU list, and it has to be always pruned (61572bb1).
>
> You don't reintroduce dentry_lru_prune here, so the two locations which
> prune dentries read as follows:
>
>
> if (dentry->d_flags & DCACHE_OP_PRUNE)
> dentry->d_op->d_prune(dentry);
>
> dentry_lru_del(dentry);
>
> I believe this is wrong. My old version would do:
>
> +static void dentry_lru_prune(struct dentry *dentry)
> +{
> + /*
> + * inform the fs via d_prune that this dentry is about to be
> + * unhashed and destroyed.
> + */
> + if (dentry->d_flags & DCACHE_OP_PRUNE)
> + dentry->d_op->d_prune(dentry);
> +
> + if (list_empty(&dentry->d_lru))
> + return;
> +
> + if ((dentry->d_flags & DCACHE_SHRINK_LIST)) {
> + list_del_init(&dentry->d_lru);
> + dentry->d_flags &= ~DCACHE_SHRINK_LIST;
> + } else {
> + spin_lock(&dentry->d_sb->s_dentry_lru_lock);
> + __dentry_lru_del(dentry);
> + spin_unlock(&dentry->d_sb->s_dentry_lru_lock);
> + }
> +}
>
> Which is SHRINK_LIST aware.
Right. Did I mention I was seeing a panic on a later patch? That's
because this patch removed the DCACHE_SHRINK_LIST check. So, the
DCACHE_SHRINK_LIST needs to move into dentry_lru_del(), and
dentry_lru_prune() can still go away. That's what my current version
of this patch does - I just didn't post it last night because it was
still running tests when I went to bed....
Cheers,
Dave.
--
Dave Chinner
david-FqsqvQoI3Ljby3iVrkZq2A@public.gmane.org
^ permalink raw reply [flat|nested] 151+ messages in thread* Re: [PATCH v7 04/31] dcache: remove dentries from LRU before putting on dispose list
@ 2013-05-14 20:32 ` Dave Chinner
0 siblings, 0 replies; 151+ messages in thread
From: Dave Chinner @ 2013-05-14 20:32 UTC (permalink / raw)
To: Glauber Costa
Cc: Glauber Costa, linux-mm, cgroups, Andrew Morton, Greg Thelen,
kamezawa.hiroyu, Michal Hocko, Johannes Weiner, linux-fsdevel,
Dave Chinner
On Tue, May 14, 2013 at 04:43:04PM +0400, Glauber Costa wrote:
> On 05/14/2013 09:46 AM, Dave Chinner wrote:
> > [ v2: don't decrement nr unused twice, spotted by Sha Zhengju ]
> > [ v7: (dchinner)
> > - shrink list leaks dentries when inode/parent can't be locked in
> > dentry_kill().
> > - fix the scope of the sb locking inside shrink_dcache_sb()
> > - remove the readdition of dentry_lru_prune(). ]
>
> Dave,
>
> dentry_lru_prune was removed because it would only prune the dentry if
> it was in the LRU list, and it has to be always pruned (61572bb1).
>
> You don't reintroduce dentry_lru_prune here, so the two locations which
> prune dentries read as follows:
>
>
> if (dentry->d_flags & DCACHE_OP_PRUNE)
> dentry->d_op->d_prune(dentry);
>
> dentry_lru_del(dentry);
>
> I believe this is wrong. My old version would do:
>
> +static void dentry_lru_prune(struct dentry *dentry)
> +{
> + /*
> + * inform the fs via d_prune that this dentry is about to be
> + * unhashed and destroyed.
> + */
> + if (dentry->d_flags & DCACHE_OP_PRUNE)
> + dentry->d_op->d_prune(dentry);
> +
> + if (list_empty(&dentry->d_lru))
> + return;
> +
> + if ((dentry->d_flags & DCACHE_SHRINK_LIST)) {
> + list_del_init(&dentry->d_lru);
> + dentry->d_flags &= ~DCACHE_SHRINK_LIST;
> + } else {
> + spin_lock(&dentry->d_sb->s_dentry_lru_lock);
> + __dentry_lru_del(dentry);
> + spin_unlock(&dentry->d_sb->s_dentry_lru_lock);
> + }
> +}
>
> Which is SHRINK_LIST aware.
Right. Did I mention I was seeing a panic on a later patch? That's
because this patch removed the DCACHE_SHRINK_LIST check. So, the
DCACHE_SHRINK_LIST needs to move into dentry_lru_del(), and
dentry_lru_prune() can still go away. That's what my current version
of this patch does - I just didn't post it last night because it was
still running tests when I went to bed....
Cheers,
Dave.
--
Dave Chinner
david@fromorbit.com
--
To unsubscribe, send a message with 'unsubscribe linux-mm' in
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^ permalink raw reply [flat|nested] 151+ messages in thread
* [PATCH v6 05/31] mm: new shrinker API
2013-05-12 18:13 ` Glauber Costa
(?)
@ 2013-05-12 18:13 ` Glauber Costa
-1 siblings, 0 replies; 151+ messages in thread
From: Glauber Costa @ 2013-05-12 18:13 UTC (permalink / raw)
To: linux-mm
Cc: cgroups, Andrew Morton, Greg Thelen, kamezawa.hiroyu,
Michal Hocko, Johannes Weiner, linux-fsdevel, Dave Chinner,
Dave Chinner, Glauber Costa
From: Dave Chinner <dchinner@redhat.com>
The current shrinker callout API uses an a single shrinker call for
multiple functions. To determine the function, a special magical
value is passed in a parameter to change the behaviour. This
complicates the implementation and return value specification for
the different behaviours.
Separate the two different behaviours into separate operations, one
to return a count of freeable objects in the cache, and another to
scan a certain number of objects in the cache for freeing. In
defining these new operations, ensure the return values and
resultant behaviours are clearly defined and documented.
Modify shrink_slab() to use the new API and implement the callouts
for all the existing shrinkers.
Signed-off-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Glauber Costa <glommer@parallels.com>
Acked-by: Mel Gorman <mgorman@suse.de>
---
include/linux/shrinker.h | 36 ++++++++++++++++++++++++----------
mm/vmscan.c | 50 +++++++++++++++++++++++++++++++-----------------
2 files changed, 58 insertions(+), 28 deletions(-)
diff --git a/include/linux/shrinker.h b/include/linux/shrinker.h
index ac6b8ee..c277b4e 100644
--- a/include/linux/shrinker.h
+++ b/include/linux/shrinker.h
@@ -4,31 +4,47 @@
/*
* This struct is used to pass information from page reclaim to the shrinkers.
* We consolidate the values for easier extention later.
+ *
+ * The 'gfpmask' refers to the allocation we are currently trying to
+ * fulfil.
+ *
+ * Note that 'shrink' will be passed nr_to_scan == 0 when the VM is
+ * querying the cache size, so a fastpath for that case is appropriate.
*/
struct shrink_control {
gfp_t gfp_mask;
/* How many slab objects shrinker() should scan and try to reclaim */
- unsigned long nr_to_scan;
+ long nr_to_scan;
};
/*
* A callback you can register to apply pressure to ageable caches.
*
- * 'sc' is passed shrink_control which includes a count 'nr_to_scan'
- * and a 'gfpmask'. It should look through the least-recently-used
- * 'nr_to_scan' entries and attempt to free them up. It should return
- * the number of objects which remain in the cache. If it returns -1, it means
- * it cannot do any scanning at this time (eg. there is a risk of deadlock).
+ * @shrink() should look through the least-recently-used 'nr_to_scan' entries
+ * and attempt to free them up. It should return the number of objects which
+ * remain in the cache. If it returns -1, it means it cannot do any scanning at
+ * this time (eg. there is a risk of deadlock).
*
- * The 'gfpmask' refers to the allocation we are currently trying to
- * fulfil.
+ * @count_objects should return the number of freeable items in the cache. If
+ * there are no objects to free or the number of freeable items cannot be
+ * determined, it should return 0. No deadlock checks should be done during the
+ * count callback - the shrinker relies on aggregating scan counts that couldn't
+ * be executed due to potential deadlocks to be run at a later call when the
+ * deadlock condition is no longer pending.
*
- * Note that 'shrink' will be passed nr_to_scan == 0 when the VM is
- * querying the cache size, so a fastpath for that case is appropriate.
+ * @scan_objects will only be called if @count_objects returned a positive
+ * value for the number of freeable objects. The callout should scan the cache
+ * and attempt to free items from the cache. It should then return the number of
+ * objects freed during the scan, or -1 if progress cannot be made due to
+ * potential deadlocks. If -1 is returned, then no further attempts to call the
+ * @scan_objects will be made from the current reclaim context.
*/
struct shrinker {
int (*shrink)(struct shrinker *, struct shrink_control *sc);
+ long (*count_objects)(struct shrinker *, struct shrink_control *sc);
+ long (*scan_objects)(struct shrinker *, struct shrink_control *sc);
+
int seeks; /* seeks to recreate an obj */
long batch; /* reclaim batch size, 0 = default */
diff --git a/mm/vmscan.c b/mm/vmscan.c
index fa6a853..fd4639c 100644
--- a/mm/vmscan.c
+++ b/mm/vmscan.c
@@ -205,19 +205,19 @@ static inline int do_shrinker_shrink(struct shrinker *shrinker,
*
* Returns the number of slab objects which we shrunk.
*/
-unsigned long shrink_slab(struct shrink_control *shrink,
+unsigned long shrink_slab(struct shrink_control *shrinkctl,
unsigned long nr_pages_scanned,
unsigned long lru_pages)
{
struct shrinker *shrinker;
- unsigned long ret = 0;
+ unsigned long freed = 0;
if (nr_pages_scanned == 0)
nr_pages_scanned = SWAP_CLUSTER_MAX;
if (!down_read_trylock(&shrinker_rwsem)) {
/* Assume we'll be able to shrink next time */
- ret = 1;
+ freed = 1;
goto out;
}
@@ -225,13 +225,16 @@ unsigned long shrink_slab(struct shrink_control *shrink,
unsigned long long delta;
long total_scan;
long max_pass;
- int shrink_ret = 0;
long nr;
long new_nr;
long batch_size = shrinker->batch ? shrinker->batch
: SHRINK_BATCH;
- max_pass = do_shrinker_shrink(shrinker, shrink, 0);
+ if (shrinker->scan_objects) {
+ max_pass = shrinker->count_objects(shrinker, shrinkctl);
+ WARN_ON(max_pass < 0);
+ } else
+ max_pass = do_shrinker_shrink(shrinker, shrinkctl, 0);
if (max_pass <= 0)
continue;
@@ -248,8 +251,8 @@ unsigned long shrink_slab(struct shrink_control *shrink,
do_div(delta, lru_pages + 1);
total_scan += delta;
if (total_scan < 0) {
- printk(KERN_ERR "shrink_slab: %pF negative objects to "
- "delete nr=%ld\n",
+ printk(KERN_ERR
+ "shrink_slab: %pF negative objects to delete nr=%ld\n",
shrinker->shrink, total_scan);
total_scan = max_pass;
}
@@ -277,20 +280,31 @@ unsigned long shrink_slab(struct shrink_control *shrink,
if (total_scan > max_pass * 2)
total_scan = max_pass * 2;
- trace_mm_shrink_slab_start(shrinker, shrink, nr,
+ trace_mm_shrink_slab_start(shrinker, shrinkctl, nr,
nr_pages_scanned, lru_pages,
max_pass, delta, total_scan);
while (total_scan >= batch_size) {
- int nr_before;
+ long ret;
+
+ if (shrinker->scan_objects) {
+ shrinkctl->nr_to_scan = batch_size;
+ ret = shrinker->scan_objects(shrinker, shrinkctl);
+
+ if (ret == -1)
+ break;
+ freed += ret;
+ } else {
+ int nr_before;
+ nr_before = do_shrinker_shrink(shrinker, shrinkctl, 0);
+ ret = do_shrinker_shrink(shrinker, shrinkctl,
+ batch_size);
+ if (ret == -1)
+ break;
+ if (ret < nr_before)
+ freed += nr_before - ret;
+ }
- nr_before = do_shrinker_shrink(shrinker, shrink, 0);
- shrink_ret = do_shrinker_shrink(shrinker, shrink,
- batch_size);
- if (shrink_ret == -1)
- break;
- if (shrink_ret < nr_before)
- ret += nr_before - shrink_ret;
count_vm_events(SLABS_SCANNED, batch_size);
total_scan -= batch_size;
@@ -308,12 +322,12 @@ unsigned long shrink_slab(struct shrink_control *shrink,
else
new_nr = atomic_long_read(&shrinker->nr_in_batch);
- trace_mm_shrink_slab_end(shrinker, shrink_ret, nr, new_nr);
+ trace_mm_shrink_slab_end(shrinker, freed, nr, new_nr);
}
up_read(&shrinker_rwsem);
out:
cond_resched();
- return ret;
+ return freed;
}
static inline int is_page_cache_freeable(struct page *page)
--
1.8.1.4
^ permalink raw reply related [flat|nested] 151+ messages in thread* [PATCH v6 05/31] mm: new shrinker API
@ 2013-05-12 18:13 ` Glauber Costa
0 siblings, 0 replies; 151+ messages in thread
From: Glauber Costa @ 2013-05-12 18:13 UTC (permalink / raw)
To: linux-mm
Cc: cgroups, Andrew Morton, Greg Thelen, kamezawa.hiroyu,
Michal Hocko, Johannes Weiner, linux-fsdevel, Dave Chinner,
Dave Chinner, Glauber Costa
From: Dave Chinner <dchinner@redhat.com>
The current shrinker callout API uses an a single shrinker call for
multiple functions. To determine the function, a special magical
value is passed in a parameter to change the behaviour. This
complicates the implementation and return value specification for
the different behaviours.
Separate the two different behaviours into separate operations, one
to return a count of freeable objects in the cache, and another to
scan a certain number of objects in the cache for freeing. In
defining these new operations, ensure the return values and
resultant behaviours are clearly defined and documented.
Modify shrink_slab() to use the new API and implement the callouts
for all the existing shrinkers.
Signed-off-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Glauber Costa <glommer@parallels.com>
Acked-by: Mel Gorman <mgorman@suse.de>
---
include/linux/shrinker.h | 36 ++++++++++++++++++++++++----------
mm/vmscan.c | 50 +++++++++++++++++++++++++++++++-----------------
2 files changed, 58 insertions(+), 28 deletions(-)
diff --git a/include/linux/shrinker.h b/include/linux/shrinker.h
index ac6b8ee..c277b4e 100644
--- a/include/linux/shrinker.h
+++ b/include/linux/shrinker.h
@@ -4,31 +4,47 @@
/*
* This struct is used to pass information from page reclaim to the shrinkers.
* We consolidate the values for easier extention later.
+ *
+ * The 'gfpmask' refers to the allocation we are currently trying to
+ * fulfil.
+ *
+ * Note that 'shrink' will be passed nr_to_scan == 0 when the VM is
+ * querying the cache size, so a fastpath for that case is appropriate.
*/
struct shrink_control {
gfp_t gfp_mask;
/* How many slab objects shrinker() should scan and try to reclaim */
- unsigned long nr_to_scan;
+ long nr_to_scan;
};
/*
* A callback you can register to apply pressure to ageable caches.
*
- * 'sc' is passed shrink_control which includes a count 'nr_to_scan'
- * and a 'gfpmask'. It should look through the least-recently-used
- * 'nr_to_scan' entries and attempt to free them up. It should return
- * the number of objects which remain in the cache. If it returns -1, it means
- * it cannot do any scanning at this time (eg. there is a risk of deadlock).
+ * @shrink() should look through the least-recently-used 'nr_to_scan' entries
+ * and attempt to free them up. It should return the number of objects which
+ * remain in the cache. If it returns -1, it means it cannot do any scanning at
+ * this time (eg. there is a risk of deadlock).
*
- * The 'gfpmask' refers to the allocation we are currently trying to
- * fulfil.
+ * @count_objects should return the number of freeable items in the cache. If
+ * there are no objects to free or the number of freeable items cannot be
+ * determined, it should return 0. No deadlock checks should be done during the
+ * count callback - the shrinker relies on aggregating scan counts that couldn't
+ * be executed due to potential deadlocks to be run at a later call when the
+ * deadlock condition is no longer pending.
*
- * Note that 'shrink' will be passed nr_to_scan == 0 when the VM is
- * querying the cache size, so a fastpath for that case is appropriate.
+ * @scan_objects will only be called if @count_objects returned a positive
+ * value for the number of freeable objects. The callout should scan the cache
+ * and attempt to free items from the cache. It should then return the number of
+ * objects freed during the scan, or -1 if progress cannot be made due to
+ * potential deadlocks. If -1 is returned, then no further attempts to call the
+ * @scan_objects will be made from the current reclaim context.
*/
struct shrinker {
int (*shrink)(struct shrinker *, struct shrink_control *sc);
+ long (*count_objects)(struct shrinker *, struct shrink_control *sc);
+ long (*scan_objects)(struct shrinker *, struct shrink_control *sc);
+
int seeks; /* seeks to recreate an obj */
long batch; /* reclaim batch size, 0 = default */
diff --git a/mm/vmscan.c b/mm/vmscan.c
index fa6a853..fd4639c 100644
--- a/mm/vmscan.c
+++ b/mm/vmscan.c
@@ -205,19 +205,19 @@ static inline int do_shrinker_shrink(struct shrinker *shrinker,
*
* Returns the number of slab objects which we shrunk.
*/
-unsigned long shrink_slab(struct shrink_control *shrink,
+unsigned long shrink_slab(struct shrink_control *shrinkctl,
unsigned long nr_pages_scanned,
unsigned long lru_pages)
{
struct shrinker *shrinker;
- unsigned long ret = 0;
+ unsigned long freed = 0;
if (nr_pages_scanned == 0)
nr_pages_scanned = SWAP_CLUSTER_MAX;
if (!down_read_trylock(&shrinker_rwsem)) {
/* Assume we'll be able to shrink next time */
- ret = 1;
+ freed = 1;
goto out;
}
@@ -225,13 +225,16 @@ unsigned long shrink_slab(struct shrink_control *shrink,
unsigned long long delta;
long total_scan;
long max_pass;
- int shrink_ret = 0;
long nr;
long new_nr;
long batch_size = shrinker->batch ? shrinker->batch
: SHRINK_BATCH;
- max_pass = do_shrinker_shrink(shrinker, shrink, 0);
+ if (shrinker->scan_objects) {
+ max_pass = shrinker->count_objects(shrinker, shrinkctl);
+ WARN_ON(max_pass < 0);
+ } else
+ max_pass = do_shrinker_shrink(shrinker, shrinkctl, 0);
if (max_pass <= 0)
continue;
@@ -248,8 +251,8 @@ unsigned long shrink_slab(struct shrink_control *shrink,
do_div(delta, lru_pages + 1);
total_scan += delta;
if (total_scan < 0) {
- printk(KERN_ERR "shrink_slab: %pF negative objects to "
- "delete nr=%ld\n",
+ printk(KERN_ERR
+ "shrink_slab: %pF negative objects to delete nr=%ld\n",
shrinker->shrink, total_scan);
total_scan = max_pass;
}
@@ -277,20 +280,31 @@ unsigned long shrink_slab(struct shrink_control *shrink,
if (total_scan > max_pass * 2)
total_scan = max_pass * 2;
- trace_mm_shrink_slab_start(shrinker, shrink, nr,
+ trace_mm_shrink_slab_start(shrinker, shrinkctl, nr,
nr_pages_scanned, lru_pages,
max_pass, delta, total_scan);
while (total_scan >= batch_size) {
- int nr_before;
+ long ret;
+
+ if (shrinker->scan_objects) {
+ shrinkctl->nr_to_scan = batch_size;
+ ret = shrinker->scan_objects(shrinker, shrinkctl);
+
+ if (ret == -1)
+ break;
+ freed += ret;
+ } else {
+ int nr_before;
+ nr_before = do_shrinker_shrink(shrinker, shrinkctl, 0);
+ ret = do_shrinker_shrink(shrinker, shrinkctl,
+ batch_size);
+ if (ret == -1)
+ break;
+ if (ret < nr_before)
+ freed += nr_before - ret;
+ }
- nr_before = do_shrinker_shrink(shrinker, shrink, 0);
- shrink_ret = do_shrinker_shrink(shrinker, shrink,
- batch_size);
- if (shrink_ret == -1)
- break;
- if (shrink_ret < nr_before)
- ret += nr_before - shrink_ret;
count_vm_events(SLABS_SCANNED, batch_size);
total_scan -= batch_size;
@@ -308,12 +322,12 @@ unsigned long shrink_slab(struct shrink_control *shrink,
else
new_nr = atomic_long_read(&shrinker->nr_in_batch);
- trace_mm_shrink_slab_end(shrinker, shrink_ret, nr, new_nr);
+ trace_mm_shrink_slab_end(shrinker, freed, nr, new_nr);
}
up_read(&shrinker_rwsem);
out:
cond_resched();
- return ret;
+ return freed;
}
static inline int is_page_cache_freeable(struct page *page)
--
1.8.1.4
^ permalink raw reply related [flat|nested] 151+ messages in thread* [PATCH v6 05/31] mm: new shrinker API
@ 2013-05-12 18:13 ` Glauber Costa
0 siblings, 0 replies; 151+ messages in thread
From: Glauber Costa @ 2013-05-12 18:13 UTC (permalink / raw)
To: linux-mm
Cc: cgroups, Andrew Morton, Greg Thelen, kamezawa.hiroyu,
Michal Hocko, Johannes Weiner, linux-fsdevel, Dave Chinner,
Dave Chinner, Glauber Costa
From: Dave Chinner <dchinner@redhat.com>
The current shrinker callout API uses an a single shrinker call for
multiple functions. To determine the function, a special magical
value is passed in a parameter to change the behaviour. This
complicates the implementation and return value specification for
the different behaviours.
Separate the two different behaviours into separate operations, one
to return a count of freeable objects in the cache, and another to
scan a certain number of objects in the cache for freeing. In
defining these new operations, ensure the return values and
resultant behaviours are clearly defined and documented.
Modify shrink_slab() to use the new API and implement the callouts
for all the existing shrinkers.
Signed-off-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Glauber Costa <glommer@parallels.com>
Acked-by: Mel Gorman <mgorman@suse.de>
---
include/linux/shrinker.h | 36 ++++++++++++++++++++++++----------
mm/vmscan.c | 50 +++++++++++++++++++++++++++++++-----------------
2 files changed, 58 insertions(+), 28 deletions(-)
diff --git a/include/linux/shrinker.h b/include/linux/shrinker.h
index ac6b8ee..c277b4e 100644
--- a/include/linux/shrinker.h
+++ b/include/linux/shrinker.h
@@ -4,31 +4,47 @@
/*
* This struct is used to pass information from page reclaim to the shrinkers.
* We consolidate the values for easier extention later.
+ *
+ * The 'gfpmask' refers to the allocation we are currently trying to
+ * fulfil.
+ *
+ * Note that 'shrink' will be passed nr_to_scan == 0 when the VM is
+ * querying the cache size, so a fastpath for that case is appropriate.
*/
struct shrink_control {
gfp_t gfp_mask;
/* How many slab objects shrinker() should scan and try to reclaim */
- unsigned long nr_to_scan;
+ long nr_to_scan;
};
/*
* A callback you can register to apply pressure to ageable caches.
*
- * 'sc' is passed shrink_control which includes a count 'nr_to_scan'
- * and a 'gfpmask'. It should look through the least-recently-used
- * 'nr_to_scan' entries and attempt to free them up. It should return
- * the number of objects which remain in the cache. If it returns -1, it means
- * it cannot do any scanning at this time (eg. there is a risk of deadlock).
+ * @shrink() should look through the least-recently-used 'nr_to_scan' entries
+ * and attempt to free them up. It should return the number of objects which
+ * remain in the cache. If it returns -1, it means it cannot do any scanning at
+ * this time (eg. there is a risk of deadlock).
*
- * The 'gfpmask' refers to the allocation we are currently trying to
- * fulfil.
+ * @count_objects should return the number of freeable items in the cache. If
+ * there are no objects to free or the number of freeable items cannot be
+ * determined, it should return 0. No deadlock checks should be done during the
+ * count callback - the shrinker relies on aggregating scan counts that couldn't
+ * be executed due to potential deadlocks to be run at a later call when the
+ * deadlock condition is no longer pending.
*
- * Note that 'shrink' will be passed nr_to_scan == 0 when the VM is
- * querying the cache size, so a fastpath for that case is appropriate.
+ * @scan_objects will only be called if @count_objects returned a positive
+ * value for the number of freeable objects. The callout should scan the cache
+ * and attempt to free items from the cache. It should then return the number of
+ * objects freed during the scan, or -1 if progress cannot be made due to
+ * potential deadlocks. If -1 is returned, then no further attempts to call the
+ * @scan_objects will be made from the current reclaim context.
*/
struct shrinker {
int (*shrink)(struct shrinker *, struct shrink_control *sc);
+ long (*count_objects)(struct shrinker *, struct shrink_control *sc);
+ long (*scan_objects)(struct shrinker *, struct shrink_control *sc);
+
int seeks; /* seeks to recreate an obj */
long batch; /* reclaim batch size, 0 = default */
diff --git a/mm/vmscan.c b/mm/vmscan.c
index fa6a853..fd4639c 100644
--- a/mm/vmscan.c
+++ b/mm/vmscan.c
@@ -205,19 +205,19 @@ static inline int do_shrinker_shrink(struct shrinker *shrinker,
*
* Returns the number of slab objects which we shrunk.
*/
-unsigned long shrink_slab(struct shrink_control *shrink,
+unsigned long shrink_slab(struct shrink_control *shrinkctl,
unsigned long nr_pages_scanned,
unsigned long lru_pages)
{
struct shrinker *shrinker;
- unsigned long ret = 0;
+ unsigned long freed = 0;
if (nr_pages_scanned == 0)
nr_pages_scanned = SWAP_CLUSTER_MAX;
if (!down_read_trylock(&shrinker_rwsem)) {
/* Assume we'll be able to shrink next time */
- ret = 1;
+ freed = 1;
goto out;
}
@@ -225,13 +225,16 @@ unsigned long shrink_slab(struct shrink_control *shrink,
unsigned long long delta;
long total_scan;
long max_pass;
- int shrink_ret = 0;
long nr;
long new_nr;
long batch_size = shrinker->batch ? shrinker->batch
: SHRINK_BATCH;
- max_pass = do_shrinker_shrink(shrinker, shrink, 0);
+ if (shrinker->scan_objects) {
+ max_pass = shrinker->count_objects(shrinker, shrinkctl);
+ WARN_ON(max_pass < 0);
+ } else
+ max_pass = do_shrinker_shrink(shrinker, shrinkctl, 0);
if (max_pass <= 0)
continue;
@@ -248,8 +251,8 @@ unsigned long shrink_slab(struct shrink_control *shrink,
do_div(delta, lru_pages + 1);
total_scan += delta;
if (total_scan < 0) {
- printk(KERN_ERR "shrink_slab: %pF negative objects to "
- "delete nr=%ld\n",
+ printk(KERN_ERR
+ "shrink_slab: %pF negative objects to delete nr=%ld\n",
shrinker->shrink, total_scan);
total_scan = max_pass;
}
@@ -277,20 +280,31 @@ unsigned long shrink_slab(struct shrink_control *shrink,
if (total_scan > max_pass * 2)
total_scan = max_pass * 2;
- trace_mm_shrink_slab_start(shrinker, shrink, nr,
+ trace_mm_shrink_slab_start(shrinker, shrinkctl, nr,
nr_pages_scanned, lru_pages,
max_pass, delta, total_scan);
while (total_scan >= batch_size) {
- int nr_before;
+ long ret;
+
+ if (shrinker->scan_objects) {
+ shrinkctl->nr_to_scan = batch_size;
+ ret = shrinker->scan_objects(shrinker, shrinkctl);
+
+ if (ret == -1)
+ break;
+ freed += ret;
+ } else {
+ int nr_before;
+ nr_before = do_shrinker_shrink(shrinker, shrinkctl, 0);
+ ret = do_shrinker_shrink(shrinker, shrinkctl,
+ batch_size);
+ if (ret == -1)
+ break;
+ if (ret < nr_before)
+ freed += nr_before - ret;
+ }
- nr_before = do_shrinker_shrink(shrinker, shrink, 0);
- shrink_ret = do_shrinker_shrink(shrinker, shrink,
- batch_size);
- if (shrink_ret == -1)
- break;
- if (shrink_ret < nr_before)
- ret += nr_before - shrink_ret;
count_vm_events(SLABS_SCANNED, batch_size);
total_scan -= batch_size;
@@ -308,12 +322,12 @@ unsigned long shrink_slab(struct shrink_control *shrink,
else
new_nr = atomic_long_read(&shrinker->nr_in_batch);
- trace_mm_shrink_slab_end(shrinker, shrink_ret, nr, new_nr);
+ trace_mm_shrink_slab_end(shrinker, freed, nr, new_nr);
}
up_read(&shrinker_rwsem);
out:
cond_resched();
- return ret;
+ return freed;
}
static inline int is_page_cache_freeable(struct page *page)
--
1.8.1.4
--
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^ permalink raw reply related [flat|nested] 151+ messages in thread
* [PATCH v6 06/31] shrinker: convert superblock shrinkers to new API
2013-05-12 18:13 ` Glauber Costa
(?)
@ 2013-05-12 18:13 ` Glauber Costa
-1 siblings, 0 replies; 151+ messages in thread
From: Glauber Costa @ 2013-05-12 18:13 UTC (permalink / raw)
To: linux-mm
Cc: cgroups, Andrew Morton, Greg Thelen, kamezawa.hiroyu,
Michal Hocko, Johannes Weiner, linux-fsdevel, Dave Chinner,
Dave Chinner, Glauber Costa
From: Dave Chinner <dchinner@redhat.com>
Convert superblock shrinker to use the new count/scan API, and
propagate the API changes through to the filesystem callouts. The
filesystem callouts already use a count/scan API, so it's just
changing counters to longs to match the VM API.
This requires the dentry and inode shrinker callouts to be converted
to the count/scan API. This is mainly a mechanical change.
[ glommer: use mult_frac for fractional proportions, build fixes ]
Signed-off-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Glauber Costa <glommer@openvz.org>
Acked-by: Mel Gorman <mgorman@suse.de>
---
fs/dcache.c | 10 +++++---
fs/inode.c | 7 +++--
fs/internal.h | 2 ++
fs/super.c | 74 ++++++++++++++++++++++++++++++++---------------------
fs/xfs/xfs_icache.c | 4 +--
fs/xfs/xfs_icache.h | 2 +-
fs/xfs/xfs_super.c | 8 +++---
include/linux/fs.h | 8 ++----
8 files changed, 67 insertions(+), 48 deletions(-)
diff --git a/fs/dcache.c b/fs/dcache.c
index 868abf9..dc0069c 100644
--- a/fs/dcache.c
+++ b/fs/dcache.c
@@ -856,11 +856,12 @@ static void shrink_dentry_list(struct list_head *list)
* This function may fail to free any resources if all the dentries are in
* use.
*/
-void prune_dcache_sb(struct super_block *sb, int count)
+long prune_dcache_sb(struct super_block *sb, unsigned long nr_to_scan)
{
struct dentry *dentry;
LIST_HEAD(referenced);
LIST_HEAD(tmp);
+ long freed = 0;
relock:
spin_lock(&sb->s_dentry_lru_lock);
@@ -885,7 +886,8 @@ relock:
this_cpu_dec(nr_dentry_unused);
sb->s_nr_dentry_unused--;
spin_unlock(&dentry->d_lock);
- if (!--count)
+ freed++;
+ if (!--nr_to_scan)
break;
}
cond_resched_lock(&sb->s_dentry_lru_lock);
@@ -895,6 +897,7 @@ relock:
spin_unlock(&sb->s_dentry_lru_lock);
shrink_dentry_list(&tmp);
+ return freed;
}
/*
@@ -1275,9 +1278,8 @@ rename_retry:
void shrink_dcache_parent(struct dentry * parent)
{
LIST_HEAD(dispose);
- int found;
- while ((found = select_parent(parent, &dispose)) != 0) {
+ while (select_parent(parent, &dispose)) {
shrink_dentry_list(&dispose);
cond_resched();
}
diff --git a/fs/inode.c b/fs/inode.c
index 00d5fc3..730aea7 100644
--- a/fs/inode.c
+++ b/fs/inode.c
@@ -704,10 +704,11 @@ static int can_unuse(struct inode *inode)
* LRU does not have strict ordering. Hence we don't want to reclaim inodes
* with this flag set because they are the inodes that are out of order.
*/
-void prune_icache_sb(struct super_block *sb, int nr_to_scan)
+long prune_icache_sb(struct super_block *sb, unsigned long nr_to_scan)
{
LIST_HEAD(freeable);
- int nr_scanned;
+ long nr_scanned;
+ long freed = 0;
unsigned long reap = 0;
spin_lock(&sb->s_inode_lru_lock);
@@ -777,6 +778,7 @@ void prune_icache_sb(struct super_block *sb, int nr_to_scan)
list_move(&inode->i_lru, &freeable);
sb->s_nr_inodes_unused--;
this_cpu_dec(nr_unused);
+ freed++;
}
if (current_is_kswapd())
__count_vm_events(KSWAPD_INODESTEAL, reap);
@@ -787,6 +789,7 @@ void prune_icache_sb(struct super_block *sb, int nr_to_scan)
current->reclaim_state->reclaimed_slab += reap;
dispose_list(&freeable);
+ return freed;
}
static void __wait_on_freeing_inode(struct inode *inode);
diff --git a/fs/internal.h b/fs/internal.h
index eaa75f7..bb7b6e4 100644
--- a/fs/internal.h
+++ b/fs/internal.h
@@ -110,6 +110,7 @@ extern int open_check_o_direct(struct file *f);
* inode.c
*/
extern spinlock_t inode_sb_list_lock;
+extern long prune_icache_sb(struct super_block *sb, unsigned long nr_to_scan);
extern void inode_add_lru(struct inode *inode);
/*
@@ -125,6 +126,7 @@ extern int invalidate_inodes(struct super_block *, bool);
* dcache.c
*/
extern struct dentry *__d_alloc(struct super_block *, const struct qstr *);
+extern long prune_dcache_sb(struct super_block *sb, unsigned long nr_to_scan);
/*
* read_write.c
diff --git a/fs/super.c b/fs/super.c
index 0be75fb..9d2f2e9 100644
--- a/fs/super.c
+++ b/fs/super.c
@@ -53,11 +53,14 @@ static char *sb_writers_name[SB_FREEZE_LEVELS] = {
* shrinker path and that leads to deadlock on the shrinker_rwsem. Hence we
* take a passive reference to the superblock to avoid this from occurring.
*/
-static int prune_super(struct shrinker *shrink, struct shrink_control *sc)
+static long super_cache_scan(struct shrinker *shrink, struct shrink_control *sc)
{
struct super_block *sb;
- int fs_objects = 0;
- int total_objects;
+ long fs_objects = 0;
+ long total_objects;
+ long freed = 0;
+ long dentries;
+ long inodes;
sb = container_of(shrink, struct super_block, s_shrink);
@@ -65,7 +68,7 @@ static int prune_super(struct shrinker *shrink, struct shrink_control *sc)
* Deadlock avoidance. We may hold various FS locks, and we don't want
* to recurse into the FS that called us in clear_inode() and friends..
*/
- if (sc->nr_to_scan && !(sc->gfp_mask & __GFP_FS))
+ if (!(sc->gfp_mask & __GFP_FS))
return -1;
if (!grab_super_passive(sb))
@@ -77,33 +80,45 @@ static int prune_super(struct shrinker *shrink, struct shrink_control *sc)
total_objects = sb->s_nr_dentry_unused +
sb->s_nr_inodes_unused + fs_objects + 1;
- if (sc->nr_to_scan) {
- int dentries;
- int inodes;
-
- /* proportion the scan between the caches */
- dentries = mult_frac(sc->nr_to_scan, sb->s_nr_dentry_unused,
- total_objects);
- inodes = mult_frac(sc->nr_to_scan, sb->s_nr_inodes_unused,
- total_objects);
- if (fs_objects)
- fs_objects = mult_frac(sc->nr_to_scan, fs_objects,
- total_objects);
- /*
- * prune the dcache first as the icache is pinned by it, then
- * prune the icache, followed by the filesystem specific caches
- */
- prune_dcache_sb(sb, dentries);
- prune_icache_sb(sb, inodes);
+ /* proportion the scan between the caches */
+ dentries = mult_frac(sc->nr_to_scan, sb->s_nr_dentry_unused,
+ total_objects);
+ inodes = mult_frac(sc->nr_to_scan, sb->s_nr_inodes_unused,
+ total_objects);
- if (fs_objects && sb->s_op->free_cached_objects) {
- sb->s_op->free_cached_objects(sb, fs_objects);
- fs_objects = sb->s_op->nr_cached_objects(sb);
- }
- total_objects = sb->s_nr_dentry_unused +
- sb->s_nr_inodes_unused + fs_objects;
+ /*
+ * prune the dcache first as the icache is pinned by it, then
+ * prune the icache, followed by the filesystem specific caches
+ */
+ freed = prune_dcache_sb(sb, dentries);
+ freed += prune_icache_sb(sb, inodes);
+
+ if (fs_objects) {
+ fs_objects = mult_frac(sc->nr_to_scan, fs_objects,
+ total_objects);
+ freed += sb->s_op->free_cached_objects(sb, fs_objects);
}
+ drop_super(sb);
+ return freed;
+}
+
+static long super_cache_count(struct shrinker *shrink, struct shrink_control *sc)
+{
+ struct super_block *sb;
+ long total_objects = 0;
+
+ sb = container_of(shrink, struct super_block, s_shrink);
+
+ if (!grab_super_passive(sb))
+ return -1;
+
+ if (sb->s_op && sb->s_op->nr_cached_objects)
+ total_objects = sb->s_op->nr_cached_objects(sb);
+
+ total_objects += sb->s_nr_dentry_unused;
+ total_objects += sb->s_nr_inodes_unused;
+
total_objects = vfs_pressure_ratio(total_objects);
drop_super(sb);
return total_objects;
@@ -217,7 +232,8 @@ static struct super_block *alloc_super(struct file_system_type *type, int flags)
s->cleancache_poolid = -1;
s->s_shrink.seeks = DEFAULT_SEEKS;
- s->s_shrink.shrink = prune_super;
+ s->s_shrink.scan_objects = super_cache_scan;
+ s->s_shrink.count_objects = super_cache_count;
s->s_shrink.batch = 1024;
}
out:
diff --git a/fs/xfs/xfs_icache.c b/fs/xfs/xfs_icache.c
index 96e344e..b35c311 100644
--- a/fs/xfs/xfs_icache.c
+++ b/fs/xfs/xfs_icache.c
@@ -1164,7 +1164,7 @@ xfs_reclaim_inodes(
* them to be cleaned, which we hope will not be very long due to the
* background walker having already kicked the IO off on those dirty inodes.
*/
-void
+long
xfs_reclaim_inodes_nr(
struct xfs_mount *mp,
int nr_to_scan)
@@ -1173,7 +1173,7 @@ xfs_reclaim_inodes_nr(
xfs_reclaim_work_queue(mp);
xfs_ail_push_all(mp->m_ail);
- xfs_reclaim_inodes_ag(mp, SYNC_TRYLOCK | SYNC_WAIT, &nr_to_scan);
+ return xfs_reclaim_inodes_ag(mp, SYNC_TRYLOCK | SYNC_WAIT, &nr_to_scan);
}
/*
diff --git a/fs/xfs/xfs_icache.h b/fs/xfs/xfs_icache.h
index e0f138c..2d6d2d3 100644
--- a/fs/xfs/xfs_icache.h
+++ b/fs/xfs/xfs_icache.h
@@ -31,7 +31,7 @@ void xfs_reclaim_worker(struct work_struct *work);
int xfs_reclaim_inodes(struct xfs_mount *mp, int mode);
int xfs_reclaim_inodes_count(struct xfs_mount *mp);
-void xfs_reclaim_inodes_nr(struct xfs_mount *mp, int nr_to_scan);
+long xfs_reclaim_inodes_nr(struct xfs_mount *mp, int nr_to_scan);
void xfs_inode_set_reclaim_tag(struct xfs_inode *ip);
diff --git a/fs/xfs/xfs_super.c b/fs/xfs/xfs_super.c
index ea341ce..1ff991b 100644
--- a/fs/xfs/xfs_super.c
+++ b/fs/xfs/xfs_super.c
@@ -1523,19 +1523,19 @@ xfs_fs_mount(
return mount_bdev(fs_type, flags, dev_name, data, xfs_fs_fill_super);
}
-static int
+static long
xfs_fs_nr_cached_objects(
struct super_block *sb)
{
return xfs_reclaim_inodes_count(XFS_M(sb));
}
-static void
+static long
xfs_fs_free_cached_objects(
struct super_block *sb,
- int nr_to_scan)
+ long nr_to_scan)
{
- xfs_reclaim_inodes_nr(XFS_M(sb), nr_to_scan);
+ return xfs_reclaim_inodes_nr(XFS_M(sb), nr_to_scan);
}
static const struct super_operations xfs_super_operations = {
diff --git a/include/linux/fs.h b/include/linux/fs.h
index 67e1040..f5eabf9 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -1326,10 +1326,6 @@ struct super_block {
int s_readonly_remount;
};
-/* superblock cache pruning functions */
-extern void prune_icache_sb(struct super_block *sb, int nr_to_scan);
-extern void prune_dcache_sb(struct super_block *sb, int nr_to_scan);
-
extern struct timespec current_fs_time(struct super_block *sb);
/*
@@ -1616,8 +1612,8 @@ struct super_operations {
ssize_t (*quota_write)(struct super_block *, int, const char *, size_t, loff_t);
#endif
int (*bdev_try_to_free_page)(struct super_block*, struct page*, gfp_t);
- int (*nr_cached_objects)(struct super_block *);
- void (*free_cached_objects)(struct super_block *, int);
+ long (*nr_cached_objects)(struct super_block *);
+ long (*free_cached_objects)(struct super_block *, long);
};
/*
--
1.8.1.4
^ permalink raw reply related [flat|nested] 151+ messages in thread* [PATCH v6 06/31] shrinker: convert superblock shrinkers to new API
@ 2013-05-12 18:13 ` Glauber Costa
0 siblings, 0 replies; 151+ messages in thread
From: Glauber Costa @ 2013-05-12 18:13 UTC (permalink / raw)
To: linux-mm
Cc: cgroups, Andrew Morton, Greg Thelen, kamezawa.hiroyu,
Michal Hocko, Johannes Weiner, linux-fsdevel, Dave Chinner,
Dave Chinner, Glauber Costa
From: Dave Chinner <dchinner@redhat.com>
Convert superblock shrinker to use the new count/scan API, and
propagate the API changes through to the filesystem callouts. The
filesystem callouts already use a count/scan API, so it's just
changing counters to longs to match the VM API.
This requires the dentry and inode shrinker callouts to be converted
to the count/scan API. This is mainly a mechanical change.
[ glommer: use mult_frac for fractional proportions, build fixes ]
Signed-off-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Glauber Costa <glommer@openvz.org>
Acked-by: Mel Gorman <mgorman@suse.de>
---
fs/dcache.c | 10 +++++---
fs/inode.c | 7 +++--
fs/internal.h | 2 ++
fs/super.c | 74 ++++++++++++++++++++++++++++++++---------------------
fs/xfs/xfs_icache.c | 4 +--
fs/xfs/xfs_icache.h | 2 +-
fs/xfs/xfs_super.c | 8 +++---
include/linux/fs.h | 8 ++----
8 files changed, 67 insertions(+), 48 deletions(-)
diff --git a/fs/dcache.c b/fs/dcache.c
index 868abf9..dc0069c 100644
--- a/fs/dcache.c
+++ b/fs/dcache.c
@@ -856,11 +856,12 @@ static void shrink_dentry_list(struct list_head *list)
* This function may fail to free any resources if all the dentries are in
* use.
*/
-void prune_dcache_sb(struct super_block *sb, int count)
+long prune_dcache_sb(struct super_block *sb, unsigned long nr_to_scan)
{
struct dentry *dentry;
LIST_HEAD(referenced);
LIST_HEAD(tmp);
+ long freed = 0;
relock:
spin_lock(&sb->s_dentry_lru_lock);
@@ -885,7 +886,8 @@ relock:
this_cpu_dec(nr_dentry_unused);
sb->s_nr_dentry_unused--;
spin_unlock(&dentry->d_lock);
- if (!--count)
+ freed++;
+ if (!--nr_to_scan)
break;
}
cond_resched_lock(&sb->s_dentry_lru_lock);
@@ -895,6 +897,7 @@ relock:
spin_unlock(&sb->s_dentry_lru_lock);
shrink_dentry_list(&tmp);
+ return freed;
}
/*
@@ -1275,9 +1278,8 @@ rename_retry:
void shrink_dcache_parent(struct dentry * parent)
{
LIST_HEAD(dispose);
- int found;
- while ((found = select_parent(parent, &dispose)) != 0) {
+ while (select_parent(parent, &dispose)) {
shrink_dentry_list(&dispose);
cond_resched();
}
diff --git a/fs/inode.c b/fs/inode.c
index 00d5fc3..730aea7 100644
--- a/fs/inode.c
+++ b/fs/inode.c
@@ -704,10 +704,11 @@ static int can_unuse(struct inode *inode)
* LRU does not have strict ordering. Hence we don't want to reclaim inodes
* with this flag set because they are the inodes that are out of order.
*/
-void prune_icache_sb(struct super_block *sb, int nr_to_scan)
+long prune_icache_sb(struct super_block *sb, unsigned long nr_to_scan)
{
LIST_HEAD(freeable);
- int nr_scanned;
+ long nr_scanned;
+ long freed = 0;
unsigned long reap = 0;
spin_lock(&sb->s_inode_lru_lock);
@@ -777,6 +778,7 @@ void prune_icache_sb(struct super_block *sb, int nr_to_scan)
list_move(&inode->i_lru, &freeable);
sb->s_nr_inodes_unused--;
this_cpu_dec(nr_unused);
+ freed++;
}
if (current_is_kswapd())
__count_vm_events(KSWAPD_INODESTEAL, reap);
@@ -787,6 +789,7 @@ void prune_icache_sb(struct super_block *sb, int nr_to_scan)
current->reclaim_state->reclaimed_slab += reap;
dispose_list(&freeable);
+ return freed;
}
static void __wait_on_freeing_inode(struct inode *inode);
diff --git a/fs/internal.h b/fs/internal.h
index eaa75f7..bb7b6e4 100644
--- a/fs/internal.h
+++ b/fs/internal.h
@@ -110,6 +110,7 @@ extern int open_check_o_direct(struct file *f);
* inode.c
*/
extern spinlock_t inode_sb_list_lock;
+extern long prune_icache_sb(struct super_block *sb, unsigned long nr_to_scan);
extern void inode_add_lru(struct inode *inode);
/*
@@ -125,6 +126,7 @@ extern int invalidate_inodes(struct super_block *, bool);
* dcache.c
*/
extern struct dentry *__d_alloc(struct super_block *, const struct qstr *);
+extern long prune_dcache_sb(struct super_block *sb, unsigned long nr_to_scan);
/*
* read_write.c
diff --git a/fs/super.c b/fs/super.c
index 0be75fb..9d2f2e9 100644
--- a/fs/super.c
+++ b/fs/super.c
@@ -53,11 +53,14 @@ static char *sb_writers_name[SB_FREEZE_LEVELS] = {
* shrinker path and that leads to deadlock on the shrinker_rwsem. Hence we
* take a passive reference to the superblock to avoid this from occurring.
*/
-static int prune_super(struct shrinker *shrink, struct shrink_control *sc)
+static long super_cache_scan(struct shrinker *shrink, struct shrink_control *sc)
{
struct super_block *sb;
- int fs_objects = 0;
- int total_objects;
+ long fs_objects = 0;
+ long total_objects;
+ long freed = 0;
+ long dentries;
+ long inodes;
sb = container_of(shrink, struct super_block, s_shrink);
@@ -65,7 +68,7 @@ static int prune_super(struct shrinker *shrink, struct shrink_control *sc)
* Deadlock avoidance. We may hold various FS locks, and we don't want
* to recurse into the FS that called us in clear_inode() and friends..
*/
- if (sc->nr_to_scan && !(sc->gfp_mask & __GFP_FS))
+ if (!(sc->gfp_mask & __GFP_FS))
return -1;
if (!grab_super_passive(sb))
@@ -77,33 +80,45 @@ static int prune_super(struct shrinker *shrink, struct shrink_control *sc)
total_objects = sb->s_nr_dentry_unused +
sb->s_nr_inodes_unused + fs_objects + 1;
- if (sc->nr_to_scan) {
- int dentries;
- int inodes;
-
- /* proportion the scan between the caches */
- dentries = mult_frac(sc->nr_to_scan, sb->s_nr_dentry_unused,
- total_objects);
- inodes = mult_frac(sc->nr_to_scan, sb->s_nr_inodes_unused,
- total_objects);
- if (fs_objects)
- fs_objects = mult_frac(sc->nr_to_scan, fs_objects,
- total_objects);
- /*
- * prune the dcache first as the icache is pinned by it, then
- * prune the icache, followed by the filesystem specific caches
- */
- prune_dcache_sb(sb, dentries);
- prune_icache_sb(sb, inodes);
+ /* proportion the scan between the caches */
+ dentries = mult_frac(sc->nr_to_scan, sb->s_nr_dentry_unused,
+ total_objects);
+ inodes = mult_frac(sc->nr_to_scan, sb->s_nr_inodes_unused,
+ total_objects);
- if (fs_objects && sb->s_op->free_cached_objects) {
- sb->s_op->free_cached_objects(sb, fs_objects);
- fs_objects = sb->s_op->nr_cached_objects(sb);
- }
- total_objects = sb->s_nr_dentry_unused +
- sb->s_nr_inodes_unused + fs_objects;
+ /*
+ * prune the dcache first as the icache is pinned by it, then
+ * prune the icache, followed by the filesystem specific caches
+ */
+ freed = prune_dcache_sb(sb, dentries);
+ freed += prune_icache_sb(sb, inodes);
+
+ if (fs_objects) {
+ fs_objects = mult_frac(sc->nr_to_scan, fs_objects,
+ total_objects);
+ freed += sb->s_op->free_cached_objects(sb, fs_objects);
}
+ drop_super(sb);
+ return freed;
+}
+
+static long super_cache_count(struct shrinker *shrink, struct shrink_control *sc)
+{
+ struct super_block *sb;
+ long total_objects = 0;
+
+ sb = container_of(shrink, struct super_block, s_shrink);
+
+ if (!grab_super_passive(sb))
+ return -1;
+
+ if (sb->s_op && sb->s_op->nr_cached_objects)
+ total_objects = sb->s_op->nr_cached_objects(sb);
+
+ total_objects += sb->s_nr_dentry_unused;
+ total_objects += sb->s_nr_inodes_unused;
+
total_objects = vfs_pressure_ratio(total_objects);
drop_super(sb);
return total_objects;
@@ -217,7 +232,8 @@ static struct super_block *alloc_super(struct file_system_type *type, int flags)
s->cleancache_poolid = -1;
s->s_shrink.seeks = DEFAULT_SEEKS;
- s->s_shrink.shrink = prune_super;
+ s->s_shrink.scan_objects = super_cache_scan;
+ s->s_shrink.count_objects = super_cache_count;
s->s_shrink.batch = 1024;
}
out:
diff --git a/fs/xfs/xfs_icache.c b/fs/xfs/xfs_icache.c
index 96e344e..b35c311 100644
--- a/fs/xfs/xfs_icache.c
+++ b/fs/xfs/xfs_icache.c
@@ -1164,7 +1164,7 @@ xfs_reclaim_inodes(
* them to be cleaned, which we hope will not be very long due to the
* background walker having already kicked the IO off on those dirty inodes.
*/
-void
+long
xfs_reclaim_inodes_nr(
struct xfs_mount *mp,
int nr_to_scan)
@@ -1173,7 +1173,7 @@ xfs_reclaim_inodes_nr(
xfs_reclaim_work_queue(mp);
xfs_ail_push_all(mp->m_ail);
- xfs_reclaim_inodes_ag(mp, SYNC_TRYLOCK | SYNC_WAIT, &nr_to_scan);
+ return xfs_reclaim_inodes_ag(mp, SYNC_TRYLOCK | SYNC_WAIT, &nr_to_scan);
}
/*
diff --git a/fs/xfs/xfs_icache.h b/fs/xfs/xfs_icache.h
index e0f138c..2d6d2d3 100644
--- a/fs/xfs/xfs_icache.h
+++ b/fs/xfs/xfs_icache.h
@@ -31,7 +31,7 @@ void xfs_reclaim_worker(struct work_struct *work);
int xfs_reclaim_inodes(struct xfs_mount *mp, int mode);
int xfs_reclaim_inodes_count(struct xfs_mount *mp);
-void xfs_reclaim_inodes_nr(struct xfs_mount *mp, int nr_to_scan);
+long xfs_reclaim_inodes_nr(struct xfs_mount *mp, int nr_to_scan);
void xfs_inode_set_reclaim_tag(struct xfs_inode *ip);
diff --git a/fs/xfs/xfs_super.c b/fs/xfs/xfs_super.c
index ea341ce..1ff991b 100644
--- a/fs/xfs/xfs_super.c
+++ b/fs/xfs/xfs_super.c
@@ -1523,19 +1523,19 @@ xfs_fs_mount(
return mount_bdev(fs_type, flags, dev_name, data, xfs_fs_fill_super);
}
-static int
+static long
xfs_fs_nr_cached_objects(
struct super_block *sb)
{
return xfs_reclaim_inodes_count(XFS_M(sb));
}
-static void
+static long
xfs_fs_free_cached_objects(
struct super_block *sb,
- int nr_to_scan)
+ long nr_to_scan)
{
- xfs_reclaim_inodes_nr(XFS_M(sb), nr_to_scan);
+ return xfs_reclaim_inodes_nr(XFS_M(sb), nr_to_scan);
}
static const struct super_operations xfs_super_operations = {
diff --git a/include/linux/fs.h b/include/linux/fs.h
index 67e1040..f5eabf9 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -1326,10 +1326,6 @@ struct super_block {
int s_readonly_remount;
};
-/* superblock cache pruning functions */
-extern void prune_icache_sb(struct super_block *sb, int nr_to_scan);
-extern void prune_dcache_sb(struct super_block *sb, int nr_to_scan);
-
extern struct timespec current_fs_time(struct super_block *sb);
/*
@@ -1616,8 +1612,8 @@ struct super_operations {
ssize_t (*quota_write)(struct super_block *, int, const char *, size_t, loff_t);
#endif
int (*bdev_try_to_free_page)(struct super_block*, struct page*, gfp_t);
- int (*nr_cached_objects)(struct super_block *);
- void (*free_cached_objects)(struct super_block *, int);
+ long (*nr_cached_objects)(struct super_block *);
+ long (*free_cached_objects)(struct super_block *, long);
};
/*
--
1.8.1.4
^ permalink raw reply related [flat|nested] 151+ messages in thread* [PATCH v6 06/31] shrinker: convert superblock shrinkers to new API
@ 2013-05-12 18:13 ` Glauber Costa
0 siblings, 0 replies; 151+ messages in thread
From: Glauber Costa @ 2013-05-12 18:13 UTC (permalink / raw)
To: linux-mm
Cc: cgroups, Andrew Morton, Greg Thelen, kamezawa.hiroyu,
Michal Hocko, Johannes Weiner, linux-fsdevel, Dave Chinner,
Dave Chinner, Glauber Costa
From: Dave Chinner <dchinner@redhat.com>
Convert superblock shrinker to use the new count/scan API, and
propagate the API changes through to the filesystem callouts. The
filesystem callouts already use a count/scan API, so it's just
changing counters to longs to match the VM API.
This requires the dentry and inode shrinker callouts to be converted
to the count/scan API. This is mainly a mechanical change.
[ glommer: use mult_frac for fractional proportions, build fixes ]
Signed-off-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Glauber Costa <glommer@openvz.org>
Acked-by: Mel Gorman <mgorman@suse.de>
---
fs/dcache.c | 10 +++++---
fs/inode.c | 7 +++--
fs/internal.h | 2 ++
fs/super.c | 74 ++++++++++++++++++++++++++++++++---------------------
fs/xfs/xfs_icache.c | 4 +--
fs/xfs/xfs_icache.h | 2 +-
fs/xfs/xfs_super.c | 8 +++---
include/linux/fs.h | 8 ++----
8 files changed, 67 insertions(+), 48 deletions(-)
diff --git a/fs/dcache.c b/fs/dcache.c
index 868abf9..dc0069c 100644
--- a/fs/dcache.c
+++ b/fs/dcache.c
@@ -856,11 +856,12 @@ static void shrink_dentry_list(struct list_head *list)
* This function may fail to free any resources if all the dentries are in
* use.
*/
-void prune_dcache_sb(struct super_block *sb, int count)
+long prune_dcache_sb(struct super_block *sb, unsigned long nr_to_scan)
{
struct dentry *dentry;
LIST_HEAD(referenced);
LIST_HEAD(tmp);
+ long freed = 0;
relock:
spin_lock(&sb->s_dentry_lru_lock);
@@ -885,7 +886,8 @@ relock:
this_cpu_dec(nr_dentry_unused);
sb->s_nr_dentry_unused--;
spin_unlock(&dentry->d_lock);
- if (!--count)
+ freed++;
+ if (!--nr_to_scan)
break;
}
cond_resched_lock(&sb->s_dentry_lru_lock);
@@ -895,6 +897,7 @@ relock:
spin_unlock(&sb->s_dentry_lru_lock);
shrink_dentry_list(&tmp);
+ return freed;
}
/*
@@ -1275,9 +1278,8 @@ rename_retry:
void shrink_dcache_parent(struct dentry * parent)
{
LIST_HEAD(dispose);
- int found;
- while ((found = select_parent(parent, &dispose)) != 0) {
+ while (select_parent(parent, &dispose)) {
shrink_dentry_list(&dispose);
cond_resched();
}
diff --git a/fs/inode.c b/fs/inode.c
index 00d5fc3..730aea7 100644
--- a/fs/inode.c
+++ b/fs/inode.c
@@ -704,10 +704,11 @@ static int can_unuse(struct inode *inode)
* LRU does not have strict ordering. Hence we don't want to reclaim inodes
* with this flag set because they are the inodes that are out of order.
*/
-void prune_icache_sb(struct super_block *sb, int nr_to_scan)
+long prune_icache_sb(struct super_block *sb, unsigned long nr_to_scan)
{
LIST_HEAD(freeable);
- int nr_scanned;
+ long nr_scanned;
+ long freed = 0;
unsigned long reap = 0;
spin_lock(&sb->s_inode_lru_lock);
@@ -777,6 +778,7 @@ void prune_icache_sb(struct super_block *sb, int nr_to_scan)
list_move(&inode->i_lru, &freeable);
sb->s_nr_inodes_unused--;
this_cpu_dec(nr_unused);
+ freed++;
}
if (current_is_kswapd())
__count_vm_events(KSWAPD_INODESTEAL, reap);
@@ -787,6 +789,7 @@ void prune_icache_sb(struct super_block *sb, int nr_to_scan)
current->reclaim_state->reclaimed_slab += reap;
dispose_list(&freeable);
+ return freed;
}
static void __wait_on_freeing_inode(struct inode *inode);
diff --git a/fs/internal.h b/fs/internal.h
index eaa75f7..bb7b6e4 100644
--- a/fs/internal.h
+++ b/fs/internal.h
@@ -110,6 +110,7 @@ extern int open_check_o_direct(struct file *f);
* inode.c
*/
extern spinlock_t inode_sb_list_lock;
+extern long prune_icache_sb(struct super_block *sb, unsigned long nr_to_scan);
extern void inode_add_lru(struct inode *inode);
/*
@@ -125,6 +126,7 @@ extern int invalidate_inodes(struct super_block *, bool);
* dcache.c
*/
extern struct dentry *__d_alloc(struct super_block *, const struct qstr *);
+extern long prune_dcache_sb(struct super_block *sb, unsigned long nr_to_scan);
/*
* read_write.c
diff --git a/fs/super.c b/fs/super.c
index 0be75fb..9d2f2e9 100644
--- a/fs/super.c
+++ b/fs/super.c
@@ -53,11 +53,14 @@ static char *sb_writers_name[SB_FREEZE_LEVELS] = {
* shrinker path and that leads to deadlock on the shrinker_rwsem. Hence we
* take a passive reference to the superblock to avoid this from occurring.
*/
-static int prune_super(struct shrinker *shrink, struct shrink_control *sc)
+static long super_cache_scan(struct shrinker *shrink, struct shrink_control *sc)
{
struct super_block *sb;
- int fs_objects = 0;
- int total_objects;
+ long fs_objects = 0;
+ long total_objects;
+ long freed = 0;
+ long dentries;
+ long inodes;
sb = container_of(shrink, struct super_block, s_shrink);
@@ -65,7 +68,7 @@ static int prune_super(struct shrinker *shrink, struct shrink_control *sc)
* Deadlock avoidance. We may hold various FS locks, and we don't want
* to recurse into the FS that called us in clear_inode() and friends..
*/
- if (sc->nr_to_scan && !(sc->gfp_mask & __GFP_FS))
+ if (!(sc->gfp_mask & __GFP_FS))
return -1;
if (!grab_super_passive(sb))
@@ -77,33 +80,45 @@ static int prune_super(struct shrinker *shrink, struct shrink_control *sc)
total_objects = sb->s_nr_dentry_unused +
sb->s_nr_inodes_unused + fs_objects + 1;
- if (sc->nr_to_scan) {
- int dentries;
- int inodes;
-
- /* proportion the scan between the caches */
- dentries = mult_frac(sc->nr_to_scan, sb->s_nr_dentry_unused,
- total_objects);
- inodes = mult_frac(sc->nr_to_scan, sb->s_nr_inodes_unused,
- total_objects);
- if (fs_objects)
- fs_objects = mult_frac(sc->nr_to_scan, fs_objects,
- total_objects);
- /*
- * prune the dcache first as the icache is pinned by it, then
- * prune the icache, followed by the filesystem specific caches
- */
- prune_dcache_sb(sb, dentries);
- prune_icache_sb(sb, inodes);
+ /* proportion the scan between the caches */
+ dentries = mult_frac(sc->nr_to_scan, sb->s_nr_dentry_unused,
+ total_objects);
+ inodes = mult_frac(sc->nr_to_scan, sb->s_nr_inodes_unused,
+ total_objects);
- if (fs_objects && sb->s_op->free_cached_objects) {
- sb->s_op->free_cached_objects(sb, fs_objects);
- fs_objects = sb->s_op->nr_cached_objects(sb);
- }
- total_objects = sb->s_nr_dentry_unused +
- sb->s_nr_inodes_unused + fs_objects;
+ /*
+ * prune the dcache first as the icache is pinned by it, then
+ * prune the icache, followed by the filesystem specific caches
+ */
+ freed = prune_dcache_sb(sb, dentries);
+ freed += prune_icache_sb(sb, inodes);
+
+ if (fs_objects) {
+ fs_objects = mult_frac(sc->nr_to_scan, fs_objects,
+ total_objects);
+ freed += sb->s_op->free_cached_objects(sb, fs_objects);
}
+ drop_super(sb);
+ return freed;
+}
+
+static long super_cache_count(struct shrinker *shrink, struct shrink_control *sc)
+{
+ struct super_block *sb;
+ long total_objects = 0;
+
+ sb = container_of(shrink, struct super_block, s_shrink);
+
+ if (!grab_super_passive(sb))
+ return -1;
+
+ if (sb->s_op && sb->s_op->nr_cached_objects)
+ total_objects = sb->s_op->nr_cached_objects(sb);
+
+ total_objects += sb->s_nr_dentry_unused;
+ total_objects += sb->s_nr_inodes_unused;
+
total_objects = vfs_pressure_ratio(total_objects);
drop_super(sb);
return total_objects;
@@ -217,7 +232,8 @@ static struct super_block *alloc_super(struct file_system_type *type, int flags)
s->cleancache_poolid = -1;
s->s_shrink.seeks = DEFAULT_SEEKS;
- s->s_shrink.shrink = prune_super;
+ s->s_shrink.scan_objects = super_cache_scan;
+ s->s_shrink.count_objects = super_cache_count;
s->s_shrink.batch = 1024;
}
out:
diff --git a/fs/xfs/xfs_icache.c b/fs/xfs/xfs_icache.c
index 96e344e..b35c311 100644
--- a/fs/xfs/xfs_icache.c
+++ b/fs/xfs/xfs_icache.c
@@ -1164,7 +1164,7 @@ xfs_reclaim_inodes(
* them to be cleaned, which we hope will not be very long due to the
* background walker having already kicked the IO off on those dirty inodes.
*/
-void
+long
xfs_reclaim_inodes_nr(
struct xfs_mount *mp,
int nr_to_scan)
@@ -1173,7 +1173,7 @@ xfs_reclaim_inodes_nr(
xfs_reclaim_work_queue(mp);
xfs_ail_push_all(mp->m_ail);
- xfs_reclaim_inodes_ag(mp, SYNC_TRYLOCK | SYNC_WAIT, &nr_to_scan);
+ return xfs_reclaim_inodes_ag(mp, SYNC_TRYLOCK | SYNC_WAIT, &nr_to_scan);
}
/*
diff --git a/fs/xfs/xfs_icache.h b/fs/xfs/xfs_icache.h
index e0f138c..2d6d2d3 100644
--- a/fs/xfs/xfs_icache.h
+++ b/fs/xfs/xfs_icache.h
@@ -31,7 +31,7 @@ void xfs_reclaim_worker(struct work_struct *work);
int xfs_reclaim_inodes(struct xfs_mount *mp, int mode);
int xfs_reclaim_inodes_count(struct xfs_mount *mp);
-void xfs_reclaim_inodes_nr(struct xfs_mount *mp, int nr_to_scan);
+long xfs_reclaim_inodes_nr(struct xfs_mount *mp, int nr_to_scan);
void xfs_inode_set_reclaim_tag(struct xfs_inode *ip);
diff --git a/fs/xfs/xfs_super.c b/fs/xfs/xfs_super.c
index ea341ce..1ff991b 100644
--- a/fs/xfs/xfs_super.c
+++ b/fs/xfs/xfs_super.c
@@ -1523,19 +1523,19 @@ xfs_fs_mount(
return mount_bdev(fs_type, flags, dev_name, data, xfs_fs_fill_super);
}
-static int
+static long
xfs_fs_nr_cached_objects(
struct super_block *sb)
{
return xfs_reclaim_inodes_count(XFS_M(sb));
}
-static void
+static long
xfs_fs_free_cached_objects(
struct super_block *sb,
- int nr_to_scan)
+ long nr_to_scan)
{
- xfs_reclaim_inodes_nr(XFS_M(sb), nr_to_scan);
+ return xfs_reclaim_inodes_nr(XFS_M(sb), nr_to_scan);
}
static const struct super_operations xfs_super_operations = {
diff --git a/include/linux/fs.h b/include/linux/fs.h
index 67e1040..f5eabf9 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -1326,10 +1326,6 @@ struct super_block {
int s_readonly_remount;
};
-/* superblock cache pruning functions */
-extern void prune_icache_sb(struct super_block *sb, int nr_to_scan);
-extern void prune_dcache_sb(struct super_block *sb, int nr_to_scan);
-
extern struct timespec current_fs_time(struct super_block *sb);
/*
@@ -1616,8 +1612,8 @@ struct super_operations {
ssize_t (*quota_write)(struct super_block *, int, const char *, size_t, loff_t);
#endif
int (*bdev_try_to_free_page)(struct super_block*, struct page*, gfp_t);
- int (*nr_cached_objects)(struct super_block *);
- void (*free_cached_objects)(struct super_block *, int);
+ long (*nr_cached_objects)(struct super_block *);
+ long (*free_cached_objects)(struct super_block *, long);
};
/*
--
1.8.1.4
--
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^ permalink raw reply related [flat|nested] 151+ messages in thread
* [PATCH v6 07/31] list: add a new LRU list type
2013-05-12 18:13 ` Glauber Costa
(?)
@ 2013-05-12 18:13 ` Glauber Costa
-1 siblings, 0 replies; 151+ messages in thread
From: Glauber Costa @ 2013-05-12 18:13 UTC (permalink / raw)
To: linux-mm
Cc: cgroups, Andrew Morton, Greg Thelen, kamezawa.hiroyu,
Michal Hocko, Johannes Weiner, linux-fsdevel, Dave Chinner,
Dave Chinner, Glauber Costa
From: Dave Chinner <dchinner@redhat.com>
Several subsystems use the same construct for LRU lists - a list
head, a spin lock and and item count. They also use exactly the same
code for adding and removing items from the LRU. Create a generic
type for these LRU lists.
This is the beginning of generic, node aware LRUs for shrinkers to
work with.
[ glommer: enum defined constants for lru. Suggested by gthelen,
don't relock over retry ]
Signed-off-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Glauber Costa <glommer@openvz.org>
Reviewed-by: Greg Thelen <gthelen@google.com>
---
include/linux/list_lru.h | 46 ++++++++++++++++++
lib/Makefile | 2 +-
lib/list_lru.c | 121 +++++++++++++++++++++++++++++++++++++++++++++++
3 files changed, 168 insertions(+), 1 deletion(-)
create mode 100644 include/linux/list_lru.h
create mode 100644 lib/list_lru.c
diff --git a/include/linux/list_lru.h b/include/linux/list_lru.h
new file mode 100644
index 0000000..4f82a57
--- /dev/null
+++ b/include/linux/list_lru.h
@@ -0,0 +1,46 @@
+/*
+ * Copyright (c) 2010-2012 Red Hat, Inc. All rights reserved.
+ * Author: David Chinner
+ *
+ * Generic LRU infrastructure
+ */
+#ifndef _LRU_LIST_H
+#define _LRU_LIST_H
+
+#include <linux/list.h>
+
+enum lru_status {
+ LRU_REMOVED, /* item removed from list */
+ LRU_ROTATE, /* item referenced, give another pass */
+ LRU_SKIP, /* item cannot be locked, skip */
+ LRU_RETRY, /* item not freeable. May drop the lock
+ internally, but has to return locked. */
+};
+
+struct list_lru {
+ spinlock_t lock;
+ struct list_head list;
+ long nr_items;
+};
+
+int list_lru_init(struct list_lru *lru);
+int list_lru_add(struct list_lru *lru, struct list_head *item);
+int list_lru_del(struct list_lru *lru, struct list_head *item);
+
+static inline unsigned long list_lru_count(struct list_lru *lru)
+{
+ return lru->nr_items;
+}
+
+typedef enum lru_status
+(*list_lru_walk_cb)(struct list_head *item, spinlock_t *lock, void *cb_arg);
+
+typedef void (*list_lru_dispose_cb)(struct list_head *dispose_list);
+
+unsigned long list_lru_walk(struct list_lru *lru, list_lru_walk_cb isolate,
+ void *cb_arg, unsigned long nr_to_walk);
+
+unsigned long
+list_lru_dispose_all(struct list_lru *lru, list_lru_dispose_cb dispose);
+
+#endif /* _LRU_LIST_H */
diff --git a/lib/Makefile b/lib/Makefile
index 3eacb2c..dbeb899 100644
--- a/lib/Makefile
+++ b/lib/Makefile
@@ -13,7 +13,7 @@ lib-y := ctype.o string.o vsprintf.o cmdline.o \
sha1.o md5.o irq_regs.o reciprocal_div.o argv_split.o \
proportions.o flex_proportions.o prio_heap.o ratelimit.o show_mem.o \
is_single_threaded.o plist.o decompress.o kobject_uevent.o \
- earlycpio.o percpu-refcount.o
+ earlycpio.o percpu-refcount.o list_lru.o
obj-$(CONFIG_ARCH_HAS_DEBUG_STRICT_USER_COPY_CHECKS) += usercopy.o
lib-$(CONFIG_MMU) += ioremap.o
diff --git a/lib/list_lru.c b/lib/list_lru.c
new file mode 100644
index 0000000..055db4b
--- /dev/null
+++ b/lib/list_lru.c
@@ -0,0 +1,121 @@
+/*
+ * Copyright (c) 2010-2012 Red Hat, Inc. All rights reserved.
+ * Author: David Chinner
+ *
+ * Generic LRU infrastructure
+ */
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/list_lru.h>
+
+int
+list_lru_add(
+ struct list_lru *lru,
+ struct list_head *item)
+{
+ spin_lock(&lru->lock);
+ if (list_empty(item)) {
+ list_add_tail(item, &lru->list);
+ lru->nr_items++;
+ spin_unlock(&lru->lock);
+ return 1;
+ }
+ spin_unlock(&lru->lock);
+ return 0;
+}
+EXPORT_SYMBOL_GPL(list_lru_add);
+
+int
+list_lru_del(
+ struct list_lru *lru,
+ struct list_head *item)
+{
+ spin_lock(&lru->lock);
+ if (!list_empty(item)) {
+ list_del_init(item);
+ lru->nr_items--;
+ spin_unlock(&lru->lock);
+ return 1;
+ }
+ spin_unlock(&lru->lock);
+ return 0;
+}
+EXPORT_SYMBOL_GPL(list_lru_del);
+
+unsigned long
+list_lru_walk(
+ struct list_lru *lru,
+ list_lru_walk_cb isolate,
+ void *cb_arg,
+ unsigned long nr_to_walk)
+{
+ struct list_head *item, *n;
+ unsigned long removed = 0;
+
+ spin_lock(&lru->lock);
+ list_for_each_safe(item, n, &lru->list) {
+ enum lru_status ret;
+ bool first_pass = true;
+restart:
+ ret = isolate(item, &lru->lock, cb_arg);
+ switch (ret) {
+ case LRU_REMOVED:
+ lru->nr_items--;
+ removed++;
+ break;
+ case LRU_ROTATE:
+ list_move_tail(item, &lru->list);
+ break;
+ case LRU_SKIP:
+ break;
+ case LRU_RETRY:
+ if (first_pass)
+ goto restart;
+ break;
+ default:
+ BUG();
+ }
+
+ if (nr_to_walk-- == 0)
+ break;
+
+ }
+ spin_unlock(&lru->lock);
+ return removed;
+}
+EXPORT_SYMBOL_GPL(list_lru_walk);
+
+unsigned long
+list_lru_dispose_all(
+ struct list_lru *lru,
+ list_lru_dispose_cb dispose)
+{
+ unsigned long disposed = 0;
+ LIST_HEAD(dispose_list);
+
+ spin_lock(&lru->lock);
+ while (!list_empty(&lru->list)) {
+ list_splice_init(&lru->list, &dispose_list);
+ disposed += lru->nr_items;
+ lru->nr_items = 0;
+ spin_unlock(&lru->lock);
+
+ dispose(&dispose_list);
+
+ spin_lock(&lru->lock);
+ }
+ spin_unlock(&lru->lock);
+ return disposed;
+}
+
+int
+list_lru_init(
+ struct list_lru *lru)
+{
+ spin_lock_init(&lru->lock);
+ INIT_LIST_HEAD(&lru->list);
+ lru->nr_items = 0;
+
+ return 0;
+}
+EXPORT_SYMBOL_GPL(list_lru_init);
--
1.8.1.4
^ permalink raw reply related [flat|nested] 151+ messages in thread* [PATCH v6 07/31] list: add a new LRU list type
@ 2013-05-12 18:13 ` Glauber Costa
0 siblings, 0 replies; 151+ messages in thread
From: Glauber Costa @ 2013-05-12 18:13 UTC (permalink / raw)
To: linux-mm
Cc: cgroups, Andrew Morton, Greg Thelen, kamezawa.hiroyu,
Michal Hocko, Johannes Weiner, linux-fsdevel, Dave Chinner,
Dave Chinner, Glauber Costa
From: Dave Chinner <dchinner@redhat.com>
Several subsystems use the same construct for LRU lists - a list
head, a spin lock and and item count. They also use exactly the same
code for adding and removing items from the LRU. Create a generic
type for these LRU lists.
This is the beginning of generic, node aware LRUs for shrinkers to
work with.
[ glommer: enum defined constants for lru. Suggested by gthelen,
don't relock over retry ]
Signed-off-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Glauber Costa <glommer@openvz.org>
Reviewed-by: Greg Thelen <gthelen@google.com>
---
include/linux/list_lru.h | 46 ++++++++++++++++++
lib/Makefile | 2 +-
lib/list_lru.c | 121 +++++++++++++++++++++++++++++++++++++++++++++++
3 files changed, 168 insertions(+), 1 deletion(-)
create mode 100644 include/linux/list_lru.h
create mode 100644 lib/list_lru.c
diff --git a/include/linux/list_lru.h b/include/linux/list_lru.h
new file mode 100644
index 0000000..4f82a57
--- /dev/null
+++ b/include/linux/list_lru.h
@@ -0,0 +1,46 @@
+/*
+ * Copyright (c) 2010-2012 Red Hat, Inc. All rights reserved.
+ * Author: David Chinner
+ *
+ * Generic LRU infrastructure
+ */
+#ifndef _LRU_LIST_H
+#define _LRU_LIST_H
+
+#include <linux/list.h>
+
+enum lru_status {
+ LRU_REMOVED, /* item removed from list */
+ LRU_ROTATE, /* item referenced, give another pass */
+ LRU_SKIP, /* item cannot be locked, skip */
+ LRU_RETRY, /* item not freeable. May drop the lock
+ internally, but has to return locked. */
+};
+
+struct list_lru {
+ spinlock_t lock;
+ struct list_head list;
+ long nr_items;
+};
+
+int list_lru_init(struct list_lru *lru);
+int list_lru_add(struct list_lru *lru, struct list_head *item);
+int list_lru_del(struct list_lru *lru, struct list_head *item);
+
+static inline unsigned long list_lru_count(struct list_lru *lru)
+{
+ return lru->nr_items;
+}
+
+typedef enum lru_status
+(*list_lru_walk_cb)(struct list_head *item, spinlock_t *lock, void *cb_arg);
+
+typedef void (*list_lru_dispose_cb)(struct list_head *dispose_list);
+
+unsigned long list_lru_walk(struct list_lru *lru, list_lru_walk_cb isolate,
+ void *cb_arg, unsigned long nr_to_walk);
+
+unsigned long
+list_lru_dispose_all(struct list_lru *lru, list_lru_dispose_cb dispose);
+
+#endif /* _LRU_LIST_H */
diff --git a/lib/Makefile b/lib/Makefile
index 3eacb2c..dbeb899 100644
--- a/lib/Makefile
+++ b/lib/Makefile
@@ -13,7 +13,7 @@ lib-y := ctype.o string.o vsprintf.o cmdline.o \
sha1.o md5.o irq_regs.o reciprocal_div.o argv_split.o \
proportions.o flex_proportions.o prio_heap.o ratelimit.o show_mem.o \
is_single_threaded.o plist.o decompress.o kobject_uevent.o \
- earlycpio.o percpu-refcount.o
+ earlycpio.o percpu-refcount.o list_lru.o
obj-$(CONFIG_ARCH_HAS_DEBUG_STRICT_USER_COPY_CHECKS) += usercopy.o
lib-$(CONFIG_MMU) += ioremap.o
diff --git a/lib/list_lru.c b/lib/list_lru.c
new file mode 100644
index 0000000..055db4b
--- /dev/null
+++ b/lib/list_lru.c
@@ -0,0 +1,121 @@
+/*
+ * Copyright (c) 2010-2012 Red Hat, Inc. All rights reserved.
+ * Author: David Chinner
+ *
+ * Generic LRU infrastructure
+ */
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/list_lru.h>
+
+int
+list_lru_add(
+ struct list_lru *lru,
+ struct list_head *item)
+{
+ spin_lock(&lru->lock);
+ if (list_empty(item)) {
+ list_add_tail(item, &lru->list);
+ lru->nr_items++;
+ spin_unlock(&lru->lock);
+ return 1;
+ }
+ spin_unlock(&lru->lock);
+ return 0;
+}
+EXPORT_SYMBOL_GPL(list_lru_add);
+
+int
+list_lru_del(
+ struct list_lru *lru,
+ struct list_head *item)
+{
+ spin_lock(&lru->lock);
+ if (!list_empty(item)) {
+ list_del_init(item);
+ lru->nr_items--;
+ spin_unlock(&lru->lock);
+ return 1;
+ }
+ spin_unlock(&lru->lock);
+ return 0;
+}
+EXPORT_SYMBOL_GPL(list_lru_del);
+
+unsigned long
+list_lru_walk(
+ struct list_lru *lru,
+ list_lru_walk_cb isolate,
+ void *cb_arg,
+ unsigned long nr_to_walk)
+{
+ struct list_head *item, *n;
+ unsigned long removed = 0;
+
+ spin_lock(&lru->lock);
+ list_for_each_safe(item, n, &lru->list) {
+ enum lru_status ret;
+ bool first_pass = true;
+restart:
+ ret = isolate(item, &lru->lock, cb_arg);
+ switch (ret) {
+ case LRU_REMOVED:
+ lru->nr_items--;
+ removed++;
+ break;
+ case LRU_ROTATE:
+ list_move_tail(item, &lru->list);
+ break;
+ case LRU_SKIP:
+ break;
+ case LRU_RETRY:
+ if (first_pass)
+ goto restart;
+ break;
+ default:
+ BUG();
+ }
+
+ if (nr_to_walk-- == 0)
+ break;
+
+ }
+ spin_unlock(&lru->lock);
+ return removed;
+}
+EXPORT_SYMBOL_GPL(list_lru_walk);
+
+unsigned long
+list_lru_dispose_all(
+ struct list_lru *lru,
+ list_lru_dispose_cb dispose)
+{
+ unsigned long disposed = 0;
+ LIST_HEAD(dispose_list);
+
+ spin_lock(&lru->lock);
+ while (!list_empty(&lru->list)) {
+ list_splice_init(&lru->list, &dispose_list);
+ disposed += lru->nr_items;
+ lru->nr_items = 0;
+ spin_unlock(&lru->lock);
+
+ dispose(&dispose_list);
+
+ spin_lock(&lru->lock);
+ }
+ spin_unlock(&lru->lock);
+ return disposed;
+}
+
+int
+list_lru_init(
+ struct list_lru *lru)
+{
+ spin_lock_init(&lru->lock);
+ INIT_LIST_HEAD(&lru->list);
+ lru->nr_items = 0;
+
+ return 0;
+}
+EXPORT_SYMBOL_GPL(list_lru_init);
--
1.8.1.4
^ permalink raw reply related [flat|nested] 151+ messages in thread* [PATCH v6 07/31] list: add a new LRU list type
@ 2013-05-12 18:13 ` Glauber Costa
0 siblings, 0 replies; 151+ messages in thread
From: Glauber Costa @ 2013-05-12 18:13 UTC (permalink / raw)
To: linux-mm
Cc: cgroups, Andrew Morton, Greg Thelen, kamezawa.hiroyu,
Michal Hocko, Johannes Weiner, linux-fsdevel, Dave Chinner,
Dave Chinner, Glauber Costa
From: Dave Chinner <dchinner@redhat.com>
Several subsystems use the same construct for LRU lists - a list
head, a spin lock and and item count. They also use exactly the same
code for adding and removing items from the LRU. Create a generic
type for these LRU lists.
This is the beginning of generic, node aware LRUs for shrinkers to
work with.
[ glommer: enum defined constants for lru. Suggested by gthelen,
don't relock over retry ]
Signed-off-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Glauber Costa <glommer@openvz.org>
Reviewed-by: Greg Thelen <gthelen@google.com>
---
include/linux/list_lru.h | 46 ++++++++++++++++++
lib/Makefile | 2 +-
lib/list_lru.c | 121 +++++++++++++++++++++++++++++++++++++++++++++++
3 files changed, 168 insertions(+), 1 deletion(-)
create mode 100644 include/linux/list_lru.h
create mode 100644 lib/list_lru.c
diff --git a/include/linux/list_lru.h b/include/linux/list_lru.h
new file mode 100644
index 0000000..4f82a57
--- /dev/null
+++ b/include/linux/list_lru.h
@@ -0,0 +1,46 @@
+/*
+ * Copyright (c) 2010-2012 Red Hat, Inc. All rights reserved.
+ * Author: David Chinner
+ *
+ * Generic LRU infrastructure
+ */
+#ifndef _LRU_LIST_H
+#define _LRU_LIST_H
+
+#include <linux/list.h>
+
+enum lru_status {
+ LRU_REMOVED, /* item removed from list */
+ LRU_ROTATE, /* item referenced, give another pass */
+ LRU_SKIP, /* item cannot be locked, skip */
+ LRU_RETRY, /* item not freeable. May drop the lock
+ internally, but has to return locked. */
+};
+
+struct list_lru {
+ spinlock_t lock;
+ struct list_head list;
+ long nr_items;
+};
+
+int list_lru_init(struct list_lru *lru);
+int list_lru_add(struct list_lru *lru, struct list_head *item);
+int list_lru_del(struct list_lru *lru, struct list_head *item);
+
+static inline unsigned long list_lru_count(struct list_lru *lru)
+{
+ return lru->nr_items;
+}
+
+typedef enum lru_status
+(*list_lru_walk_cb)(struct list_head *item, spinlock_t *lock, void *cb_arg);
+
+typedef void (*list_lru_dispose_cb)(struct list_head *dispose_list);
+
+unsigned long list_lru_walk(struct list_lru *lru, list_lru_walk_cb isolate,
+ void *cb_arg, unsigned long nr_to_walk);
+
+unsigned long
+list_lru_dispose_all(struct list_lru *lru, list_lru_dispose_cb dispose);
+
+#endif /* _LRU_LIST_H */
diff --git a/lib/Makefile b/lib/Makefile
index 3eacb2c..dbeb899 100644
--- a/lib/Makefile
+++ b/lib/Makefile
@@ -13,7 +13,7 @@ lib-y := ctype.o string.o vsprintf.o cmdline.o \
sha1.o md5.o irq_regs.o reciprocal_div.o argv_split.o \
proportions.o flex_proportions.o prio_heap.o ratelimit.o show_mem.o \
is_single_threaded.o plist.o decompress.o kobject_uevent.o \
- earlycpio.o percpu-refcount.o
+ earlycpio.o percpu-refcount.o list_lru.o
obj-$(CONFIG_ARCH_HAS_DEBUG_STRICT_USER_COPY_CHECKS) += usercopy.o
lib-$(CONFIG_MMU) += ioremap.o
diff --git a/lib/list_lru.c b/lib/list_lru.c
new file mode 100644
index 0000000..055db4b
--- /dev/null
+++ b/lib/list_lru.c
@@ -0,0 +1,121 @@
+/*
+ * Copyright (c) 2010-2012 Red Hat, Inc. All rights reserved.
+ * Author: David Chinner
+ *
+ * Generic LRU infrastructure
+ */
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/list_lru.h>
+
+int
+list_lru_add(
+ struct list_lru *lru,
+ struct list_head *item)
+{
+ spin_lock(&lru->lock);
+ if (list_empty(item)) {
+ list_add_tail(item, &lru->list);
+ lru->nr_items++;
+ spin_unlock(&lru->lock);
+ return 1;
+ }
+ spin_unlock(&lru->lock);
+ return 0;
+}
+EXPORT_SYMBOL_GPL(list_lru_add);
+
+int
+list_lru_del(
+ struct list_lru *lru,
+ struct list_head *item)
+{
+ spin_lock(&lru->lock);
+ if (!list_empty(item)) {
+ list_del_init(item);
+ lru->nr_items--;
+ spin_unlock(&lru->lock);
+ return 1;
+ }
+ spin_unlock(&lru->lock);
+ return 0;
+}
+EXPORT_SYMBOL_GPL(list_lru_del);
+
+unsigned long
+list_lru_walk(
+ struct list_lru *lru,
+ list_lru_walk_cb isolate,
+ void *cb_arg,
+ unsigned long nr_to_walk)
+{
+ struct list_head *item, *n;
+ unsigned long removed = 0;
+
+ spin_lock(&lru->lock);
+ list_for_each_safe(item, n, &lru->list) {
+ enum lru_status ret;
+ bool first_pass = true;
+restart:
+ ret = isolate(item, &lru->lock, cb_arg);
+ switch (ret) {
+ case LRU_REMOVED:
+ lru->nr_items--;
+ removed++;
+ break;
+ case LRU_ROTATE:
+ list_move_tail(item, &lru->list);
+ break;
+ case LRU_SKIP:
+ break;
+ case LRU_RETRY:
+ if (first_pass)
+ goto restart;
+ break;
+ default:
+ BUG();
+ }
+
+ if (nr_to_walk-- == 0)
+ break;
+
+ }
+ spin_unlock(&lru->lock);
+ return removed;
+}
+EXPORT_SYMBOL_GPL(list_lru_walk);
+
+unsigned long
+list_lru_dispose_all(
+ struct list_lru *lru,
+ list_lru_dispose_cb dispose)
+{
+ unsigned long disposed = 0;
+ LIST_HEAD(dispose_list);
+
+ spin_lock(&lru->lock);
+ while (!list_empty(&lru->list)) {
+ list_splice_init(&lru->list, &dispose_list);
+ disposed += lru->nr_items;
+ lru->nr_items = 0;
+ spin_unlock(&lru->lock);
+
+ dispose(&dispose_list);
+
+ spin_lock(&lru->lock);
+ }
+ spin_unlock(&lru->lock);
+ return disposed;
+}
+
+int
+list_lru_init(
+ struct list_lru *lru)
+{
+ spin_lock_init(&lru->lock);
+ INIT_LIST_HEAD(&lru->list);
+ lru->nr_items = 0;
+
+ return 0;
+}
+EXPORT_SYMBOL_GPL(list_lru_init);
--
1.8.1.4
--
To unsubscribe, send a message with 'unsubscribe linux-mm' in
the body to majordomo@kvack.org. For more info on Linux MM,
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^ permalink raw reply related [flat|nested] 151+ messages in thread* Re: [PATCH v6 07/31] list: add a new LRU list type
2013-05-12 18:13 ` Glauber Costa
(?)
(?)
@ 2013-05-13 9:25 ` Mel Gorman
-1 siblings, 0 replies; 151+ messages in thread
From: Mel Gorman @ 2013-05-13 9:25 UTC (permalink / raw)
To: Glauber Costa
Cc: linux-mm, cgroups, Andrew Morton, Greg Thelen, kamezawa.hiroyu,
Michal Hocko, Johannes Weiner, linux-fsdevel, Dave Chinner,
Dave Chinner
On Sun, May 12, 2013 at 10:13:28PM +0400, Glauber Costa wrote:
> From: Dave Chinner <dchinner@redhat.com>
>
> Several subsystems use the same construct for LRU lists - a list
> head, a spin lock and and item count. They also use exactly the same
> code for adding and removing items from the LRU. Create a generic
> type for these LRU lists.
>
> This is the beginning of generic, node aware LRUs for shrinkers to
> work with.
>
> [ glommer: enum defined constants for lru. Suggested by gthelen,
> don't relock over retry ]
> Signed-off-by: Dave Chinner <dchinner@redhat.com>
> Signed-off-by: Glauber Costa <glommer@openvz.org>
> Reviewed-by: Greg Thelen <gthelen@google.com>
Acked-by: Mel Gorman <mgorman@suse.de>
--
Mel Gorman
SUSE Labs
--
To unsubscribe, send a message with 'unsubscribe linux-mm' in
the body to majordomo@kvack.org. For more info on Linux MM,
see: http://www.linux-mm.org/ .
Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a>
^ permalink raw reply [flat|nested] 151+ messages in thread
* [PATCH v6 08/31] inode: convert inode lru list to generic lru list code.
2013-05-12 18:13 ` Glauber Costa
(?)
@ 2013-05-12 18:13 ` Glauber Costa
-1 siblings, 0 replies; 151+ messages in thread
From: Glauber Costa @ 2013-05-12 18:13 UTC (permalink / raw)
To: linux-mm
Cc: cgroups, Andrew Morton, Greg Thelen, kamezawa.hiroyu,
Michal Hocko, Johannes Weiner, linux-fsdevel, Dave Chinner,
Dave Chinner, Glauber Costa
From: Dave Chinner <dchinner@redhat.com>
[ glommer: adapted for new LRU return codes ]
Signed-off-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Glauber Costa <glommer@openvz.org>
---
fs/inode.c | 175 +++++++++++++++++++++--------------------------------
fs/super.c | 12 ++--
include/linux/fs.h | 6 +-
3 files changed, 77 insertions(+), 116 deletions(-)
diff --git a/fs/inode.c b/fs/inode.c
index 730aea7..ff66f49 100644
--- a/fs/inode.c
+++ b/fs/inode.c
@@ -17,6 +17,7 @@
#include <linux/prefetch.h>
#include <linux/buffer_head.h> /* for inode_has_buffers */
#include <linux/ratelimit.h>
+#include <linux/list_lru.h>
#include "internal.h"
/*
@@ -24,7 +25,7 @@
*
* inode->i_lock protects:
* inode->i_state, inode->i_hash, __iget()
- * inode->i_sb->s_inode_lru_lock protects:
+ * Inode LRU list locks protect:
* inode->i_sb->s_inode_lru, inode->i_lru
* inode_sb_list_lock protects:
* sb->s_inodes, inode->i_sb_list
@@ -37,7 +38,7 @@
*
* inode_sb_list_lock
* inode->i_lock
- * inode->i_sb->s_inode_lru_lock
+ * Inode LRU list locks
*
* bdi->wb.list_lock
* inode->i_lock
@@ -399,13 +400,8 @@ EXPORT_SYMBOL(ihold);
static void inode_lru_list_add(struct inode *inode)
{
- spin_lock(&inode->i_sb->s_inode_lru_lock);
- if (list_empty(&inode->i_lru)) {
- list_add(&inode->i_lru, &inode->i_sb->s_inode_lru);
- inode->i_sb->s_nr_inodes_unused++;
+ if (list_lru_add(&inode->i_sb->s_inode_lru, &inode->i_lru))
this_cpu_inc(nr_unused);
- }
- spin_unlock(&inode->i_sb->s_inode_lru_lock);
}
/*
@@ -423,13 +419,9 @@ void inode_add_lru(struct inode *inode)
static void inode_lru_list_del(struct inode *inode)
{
- spin_lock(&inode->i_sb->s_inode_lru_lock);
- if (!list_empty(&inode->i_lru)) {
- list_del_init(&inode->i_lru);
- inode->i_sb->s_nr_inodes_unused--;
+
+ if (list_lru_del(&inode->i_sb->s_inode_lru, &inode->i_lru))
this_cpu_dec(nr_unused);
- }
- spin_unlock(&inode->i_sb->s_inode_lru_lock);
}
/**
@@ -673,24 +665,8 @@ int invalidate_inodes(struct super_block *sb, bool kill_dirty)
return busy;
}
-static int can_unuse(struct inode *inode)
-{
- if (inode->i_state & ~I_REFERENCED)
- return 0;
- if (inode_has_buffers(inode))
- return 0;
- if (atomic_read(&inode->i_count))
- return 0;
- if (inode->i_data.nrpages)
- return 0;
- return 1;
-}
-
/*
- * Walk the superblock inode LRU for freeable inodes and attempt to free them.
- * This is called from the superblock shrinker function with a number of inodes
- * to trim from the LRU. Inodes to be freed are moved to a temporary list and
- * then are freed outside inode_lock by dispose_list().
+ * Isolate the inode from the LRU in preparation for freeing it.
*
* Any inodes which are pinned purely because of attached pagecache have their
* pagecache removed. If the inode has metadata buffers attached to
@@ -704,90 +680,79 @@ static int can_unuse(struct inode *inode)
* LRU does not have strict ordering. Hence we don't want to reclaim inodes
* with this flag set because they are the inodes that are out of order.
*/
-long prune_icache_sb(struct super_block *sb, unsigned long nr_to_scan)
+static enum lru_status
+inode_lru_isolate(struct list_head *item, spinlock_t *lru_lock, void *arg)
{
- LIST_HEAD(freeable);
- long nr_scanned;
- long freed = 0;
- unsigned long reap = 0;
+ struct list_head *freeable = arg;
+ struct inode *inode = container_of(item, struct inode, i_lru);
- spin_lock(&sb->s_inode_lru_lock);
- for (nr_scanned = nr_to_scan; nr_scanned >= 0; nr_scanned--) {
- struct inode *inode;
+ /*
+ * we are inverting the lru lock/inode->i_lock here, so use a trylock.
+ * If we fail to get the lock, just skip it.
+ */
+ if (!spin_trylock(&inode->i_lock))
+ return LRU_SKIP;
- if (list_empty(&sb->s_inode_lru))
- break;
+ /*
+ * Referenced or dirty inodes are still in use. Give them another pass
+ * through the LRU as we canot reclaim them now.
+ */
+ if (atomic_read(&inode->i_count) ||
+ (inode->i_state & ~I_REFERENCED)) {
+ list_del_init(&inode->i_lru);
+ spin_unlock(&inode->i_lock);
+ this_cpu_dec(nr_unused);
+ return LRU_REMOVED;
+ }
- inode = list_entry(sb->s_inode_lru.prev, struct inode, i_lru);
+ /* recently referenced inodes get one more pass */
+ if (inode->i_state & I_REFERENCED) {
+ inode->i_state &= ~I_REFERENCED;
+ spin_unlock(&inode->i_lock);
+ return LRU_ROTATE;
+ }
- /*
- * we are inverting the sb->s_inode_lru_lock/inode->i_lock here,
- * so use a trylock. If we fail to get the lock, just move the
- * inode to the back of the list so we don't spin on it.
- */
- if (!spin_trylock(&inode->i_lock)) {
- list_move(&inode->i_lru, &sb->s_inode_lru);
- continue;
+ if (inode_has_buffers(inode) || inode->i_data.nrpages) {
+ __iget(inode);
+ spin_unlock(&inode->i_lock);
+ spin_unlock(lru_lock);
+ if (remove_inode_buffers(inode)) {
+ unsigned long reap;
+ reap = invalidate_mapping_pages(&inode->i_data, 0, -1);
+ if (current_is_kswapd())
+ __count_vm_events(KSWAPD_INODESTEAL, reap);
+ else
+ __count_vm_events(PGINODESTEAL, reap);
+ if (current->reclaim_state)
+ current->reclaim_state->reclaimed_slab += reap;
}
+ iput(inode);
+ spin_lock(lru_lock);
+ return LRU_RETRY;
+ }
- /*
- * Referenced or dirty inodes are still in use. Give them
- * another pass through the LRU as we canot reclaim them now.
- */
- if (atomic_read(&inode->i_count) ||
- (inode->i_state & ~I_REFERENCED)) {
- list_del_init(&inode->i_lru);
- spin_unlock(&inode->i_lock);
- sb->s_nr_inodes_unused--;
- this_cpu_dec(nr_unused);
- continue;
- }
+ WARN_ON(inode->i_state & I_NEW);
+ inode->i_state |= I_FREEING;
+ spin_unlock(&inode->i_lock);
- /* recently referenced inodes get one more pass */
- if (inode->i_state & I_REFERENCED) {
- inode->i_state &= ~I_REFERENCED;
- list_move(&inode->i_lru, &sb->s_inode_lru);
- spin_unlock(&inode->i_lock);
- continue;
- }
- if (inode_has_buffers(inode) || inode->i_data.nrpages) {
- __iget(inode);
- spin_unlock(&inode->i_lock);
- spin_unlock(&sb->s_inode_lru_lock);
- if (remove_inode_buffers(inode))
- reap += invalidate_mapping_pages(&inode->i_data,
- 0, -1);
- iput(inode);
- spin_lock(&sb->s_inode_lru_lock);
-
- if (inode != list_entry(sb->s_inode_lru.next,
- struct inode, i_lru))
- continue; /* wrong inode or list_empty */
- /* avoid lock inversions with trylock */
- if (!spin_trylock(&inode->i_lock))
- continue;
- if (!can_unuse(inode)) {
- spin_unlock(&inode->i_lock);
- continue;
- }
- }
- WARN_ON(inode->i_state & I_NEW);
- inode->i_state |= I_FREEING;
- spin_unlock(&inode->i_lock);
+ list_move(&inode->i_lru, freeable);
+ this_cpu_dec(nr_unused);
+ return LRU_REMOVED;
+}
- list_move(&inode->i_lru, &freeable);
- sb->s_nr_inodes_unused--;
- this_cpu_dec(nr_unused);
- freed++;
- }
- if (current_is_kswapd())
- __count_vm_events(KSWAPD_INODESTEAL, reap);
- else
- __count_vm_events(PGINODESTEAL, reap);
- spin_unlock(&sb->s_inode_lru_lock);
- if (current->reclaim_state)
- current->reclaim_state->reclaimed_slab += reap;
+/*
+ * Walk the superblock inode LRU for freeable inodes and attempt to free them.
+ * This is called from the superblock shrinker function with a number of inodes
+ * to trim from the LRU. Inodes to be freed are moved to a temporary list and
+ * then are freed outside inode_lock by dispose_list().
+ */
+long prune_icache_sb(struct super_block *sb, unsigned long nr_to_scan)
+{
+ LIST_HEAD(freeable);
+ long freed;
+ freed = list_lru_walk(&sb->s_inode_lru, inode_lru_isolate,
+ &freeable, nr_to_scan);
dispose_list(&freeable);
return freed;
}
diff --git a/fs/super.c b/fs/super.c
index 9d2f2e9..9049110 100644
--- a/fs/super.c
+++ b/fs/super.c
@@ -77,14 +77,13 @@ static long super_cache_scan(struct shrinker *shrink, struct shrink_control *sc)
if (sb->s_op && sb->s_op->nr_cached_objects)
fs_objects = sb->s_op->nr_cached_objects(sb);
- total_objects = sb->s_nr_dentry_unused +
- sb->s_nr_inodes_unused + fs_objects + 1;
+ inodes = list_lru_count(&sb->s_inode_lru);
+ total_objects = sb->s_nr_dentry_unused + inodes + fs_objects + 1;
/* proportion the scan between the caches */
dentries = mult_frac(sc->nr_to_scan, sb->s_nr_dentry_unused,
total_objects);
- inodes = mult_frac(sc->nr_to_scan, sb->s_nr_inodes_unused,
- total_objects);
+ inodes = mult_frac(sc->nr_to_scan, inodes, total_objects);
/*
* prune the dcache first as the icache is pinned by it, then
@@ -117,7 +116,7 @@ static long super_cache_count(struct shrinker *shrink, struct shrink_control *sc
total_objects = sb->s_op->nr_cached_objects(sb);
total_objects += sb->s_nr_dentry_unused;
- total_objects += sb->s_nr_inodes_unused;
+ total_objects += list_lru_count(&sb->s_inode_lru);
total_objects = vfs_pressure_ratio(total_objects);
drop_super(sb);
@@ -198,8 +197,7 @@ static struct super_block *alloc_super(struct file_system_type *type, int flags)
INIT_LIST_HEAD(&s->s_inodes);
INIT_LIST_HEAD(&s->s_dentry_lru);
spin_lock_init(&s->s_dentry_lru_lock);
- INIT_LIST_HEAD(&s->s_inode_lru);
- spin_lock_init(&s->s_inode_lru_lock);
+ list_lru_init(&s->s_inode_lru);
INIT_LIST_HEAD(&s->s_mounts);
init_rwsem(&s->s_umount);
lockdep_set_class(&s->s_umount, &type->s_umount_key);
diff --git a/include/linux/fs.h b/include/linux/fs.h
index f5eabf9..4442613 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -10,6 +10,7 @@
#include <linux/stat.h>
#include <linux/cache.h>
#include <linux/list.h>
+#include <linux/list_lru.h>
#include <linux/radix-tree.h>
#include <linux/rbtree.h>
#include <linux/init.h>
@@ -1269,10 +1270,7 @@ struct super_block {
struct list_head s_dentry_lru; /* unused dentry lru */
int s_nr_dentry_unused; /* # of dentry on lru */
- /* s_inode_lru_lock protects s_inode_lru and s_nr_inodes_unused */
- spinlock_t s_inode_lru_lock ____cacheline_aligned_in_smp;
- struct list_head s_inode_lru; /* unused inode lru */
- int s_nr_inodes_unused; /* # of inodes on lru */
+ struct list_lru s_inode_lru ____cacheline_aligned_in_smp;
struct block_device *s_bdev;
struct backing_dev_info *s_bdi;
--
1.8.1.4
^ permalink raw reply related [flat|nested] 151+ messages in thread* [PATCH v6 08/31] inode: convert inode lru list to generic lru list code.
@ 2013-05-12 18:13 ` Glauber Costa
0 siblings, 0 replies; 151+ messages in thread
From: Glauber Costa @ 2013-05-12 18:13 UTC (permalink / raw)
To: linux-mm
Cc: cgroups, Andrew Morton, Greg Thelen, kamezawa.hiroyu,
Michal Hocko, Johannes Weiner, linux-fsdevel, Dave Chinner,
Dave Chinner, Glauber Costa
From: Dave Chinner <dchinner@redhat.com>
[ glommer: adapted for new LRU return codes ]
Signed-off-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Glauber Costa <glommer@openvz.org>
---
fs/inode.c | 175 +++++++++++++++++++++--------------------------------
fs/super.c | 12 ++--
include/linux/fs.h | 6 +-
3 files changed, 77 insertions(+), 116 deletions(-)
diff --git a/fs/inode.c b/fs/inode.c
index 730aea7..ff66f49 100644
--- a/fs/inode.c
+++ b/fs/inode.c
@@ -17,6 +17,7 @@
#include <linux/prefetch.h>
#include <linux/buffer_head.h> /* for inode_has_buffers */
#include <linux/ratelimit.h>
+#include <linux/list_lru.h>
#include "internal.h"
/*
@@ -24,7 +25,7 @@
*
* inode->i_lock protects:
* inode->i_state, inode->i_hash, __iget()
- * inode->i_sb->s_inode_lru_lock protects:
+ * Inode LRU list locks protect:
* inode->i_sb->s_inode_lru, inode->i_lru
* inode_sb_list_lock protects:
* sb->s_inodes, inode->i_sb_list
@@ -37,7 +38,7 @@
*
* inode_sb_list_lock
* inode->i_lock
- * inode->i_sb->s_inode_lru_lock
+ * Inode LRU list locks
*
* bdi->wb.list_lock
* inode->i_lock
@@ -399,13 +400,8 @@ EXPORT_SYMBOL(ihold);
static void inode_lru_list_add(struct inode *inode)
{
- spin_lock(&inode->i_sb->s_inode_lru_lock);
- if (list_empty(&inode->i_lru)) {
- list_add(&inode->i_lru, &inode->i_sb->s_inode_lru);
- inode->i_sb->s_nr_inodes_unused++;
+ if (list_lru_add(&inode->i_sb->s_inode_lru, &inode->i_lru))
this_cpu_inc(nr_unused);
- }
- spin_unlock(&inode->i_sb->s_inode_lru_lock);
}
/*
@@ -423,13 +419,9 @@ void inode_add_lru(struct inode *inode)
static void inode_lru_list_del(struct inode *inode)
{
- spin_lock(&inode->i_sb->s_inode_lru_lock);
- if (!list_empty(&inode->i_lru)) {
- list_del_init(&inode->i_lru);
- inode->i_sb->s_nr_inodes_unused--;
+
+ if (list_lru_del(&inode->i_sb->s_inode_lru, &inode->i_lru))
this_cpu_dec(nr_unused);
- }
- spin_unlock(&inode->i_sb->s_inode_lru_lock);
}
/**
@@ -673,24 +665,8 @@ int invalidate_inodes(struct super_block *sb, bool kill_dirty)
return busy;
}
-static int can_unuse(struct inode *inode)
-{
- if (inode->i_state & ~I_REFERENCED)
- return 0;
- if (inode_has_buffers(inode))
- return 0;
- if (atomic_read(&inode->i_count))
- return 0;
- if (inode->i_data.nrpages)
- return 0;
- return 1;
-}
-
/*
- * Walk the superblock inode LRU for freeable inodes and attempt to free them.
- * This is called from the superblock shrinker function with a number of inodes
- * to trim from the LRU. Inodes to be freed are moved to a temporary list and
- * then are freed outside inode_lock by dispose_list().
+ * Isolate the inode from the LRU in preparation for freeing it.
*
* Any inodes which are pinned purely because of attached pagecache have their
* pagecache removed. If the inode has metadata buffers attached to
@@ -704,90 +680,79 @@ static int can_unuse(struct inode *inode)
* LRU does not have strict ordering. Hence we don't want to reclaim inodes
* with this flag set because they are the inodes that are out of order.
*/
-long prune_icache_sb(struct super_block *sb, unsigned long nr_to_scan)
+static enum lru_status
+inode_lru_isolate(struct list_head *item, spinlock_t *lru_lock, void *arg)
{
- LIST_HEAD(freeable);
- long nr_scanned;
- long freed = 0;
- unsigned long reap = 0;
+ struct list_head *freeable = arg;
+ struct inode *inode = container_of(item, struct inode, i_lru);
- spin_lock(&sb->s_inode_lru_lock);
- for (nr_scanned = nr_to_scan; nr_scanned >= 0; nr_scanned--) {
- struct inode *inode;
+ /*
+ * we are inverting the lru lock/inode->i_lock here, so use a trylock.
+ * If we fail to get the lock, just skip it.
+ */
+ if (!spin_trylock(&inode->i_lock))
+ return LRU_SKIP;
- if (list_empty(&sb->s_inode_lru))
- break;
+ /*
+ * Referenced or dirty inodes are still in use. Give them another pass
+ * through the LRU as we canot reclaim them now.
+ */
+ if (atomic_read(&inode->i_count) ||
+ (inode->i_state & ~I_REFERENCED)) {
+ list_del_init(&inode->i_lru);
+ spin_unlock(&inode->i_lock);
+ this_cpu_dec(nr_unused);
+ return LRU_REMOVED;
+ }
- inode = list_entry(sb->s_inode_lru.prev, struct inode, i_lru);
+ /* recently referenced inodes get one more pass */
+ if (inode->i_state & I_REFERENCED) {
+ inode->i_state &= ~I_REFERENCED;
+ spin_unlock(&inode->i_lock);
+ return LRU_ROTATE;
+ }
- /*
- * we are inverting the sb->s_inode_lru_lock/inode->i_lock here,
- * so use a trylock. If we fail to get the lock, just move the
- * inode to the back of the list so we don't spin on it.
- */
- if (!spin_trylock(&inode->i_lock)) {
- list_move(&inode->i_lru, &sb->s_inode_lru);
- continue;
+ if (inode_has_buffers(inode) || inode->i_data.nrpages) {
+ __iget(inode);
+ spin_unlock(&inode->i_lock);
+ spin_unlock(lru_lock);
+ if (remove_inode_buffers(inode)) {
+ unsigned long reap;
+ reap = invalidate_mapping_pages(&inode->i_data, 0, -1);
+ if (current_is_kswapd())
+ __count_vm_events(KSWAPD_INODESTEAL, reap);
+ else
+ __count_vm_events(PGINODESTEAL, reap);
+ if (current->reclaim_state)
+ current->reclaim_state->reclaimed_slab += reap;
}
+ iput(inode);
+ spin_lock(lru_lock);
+ return LRU_RETRY;
+ }
- /*
- * Referenced or dirty inodes are still in use. Give them
- * another pass through the LRU as we canot reclaim them now.
- */
- if (atomic_read(&inode->i_count) ||
- (inode->i_state & ~I_REFERENCED)) {
- list_del_init(&inode->i_lru);
- spin_unlock(&inode->i_lock);
- sb->s_nr_inodes_unused--;
- this_cpu_dec(nr_unused);
- continue;
- }
+ WARN_ON(inode->i_state & I_NEW);
+ inode->i_state |= I_FREEING;
+ spin_unlock(&inode->i_lock);
- /* recently referenced inodes get one more pass */
- if (inode->i_state & I_REFERENCED) {
- inode->i_state &= ~I_REFERENCED;
- list_move(&inode->i_lru, &sb->s_inode_lru);
- spin_unlock(&inode->i_lock);
- continue;
- }
- if (inode_has_buffers(inode) || inode->i_data.nrpages) {
- __iget(inode);
- spin_unlock(&inode->i_lock);
- spin_unlock(&sb->s_inode_lru_lock);
- if (remove_inode_buffers(inode))
- reap += invalidate_mapping_pages(&inode->i_data,
- 0, -1);
- iput(inode);
- spin_lock(&sb->s_inode_lru_lock);
-
- if (inode != list_entry(sb->s_inode_lru.next,
- struct inode, i_lru))
- continue; /* wrong inode or list_empty */
- /* avoid lock inversions with trylock */
- if (!spin_trylock(&inode->i_lock))
- continue;
- if (!can_unuse(inode)) {
- spin_unlock(&inode->i_lock);
- continue;
- }
- }
- WARN_ON(inode->i_state & I_NEW);
- inode->i_state |= I_FREEING;
- spin_unlock(&inode->i_lock);
+ list_move(&inode->i_lru, freeable);
+ this_cpu_dec(nr_unused);
+ return LRU_REMOVED;
+}
- list_move(&inode->i_lru, &freeable);
- sb->s_nr_inodes_unused--;
- this_cpu_dec(nr_unused);
- freed++;
- }
- if (current_is_kswapd())
- __count_vm_events(KSWAPD_INODESTEAL, reap);
- else
- __count_vm_events(PGINODESTEAL, reap);
- spin_unlock(&sb->s_inode_lru_lock);
- if (current->reclaim_state)
- current->reclaim_state->reclaimed_slab += reap;
+/*
+ * Walk the superblock inode LRU for freeable inodes and attempt to free them.
+ * This is called from the superblock shrinker function with a number of inodes
+ * to trim from the LRU. Inodes to be freed are moved to a temporary list and
+ * then are freed outside inode_lock by dispose_list().
+ */
+long prune_icache_sb(struct super_block *sb, unsigned long nr_to_scan)
+{
+ LIST_HEAD(freeable);
+ long freed;
+ freed = list_lru_walk(&sb->s_inode_lru, inode_lru_isolate,
+ &freeable, nr_to_scan);
dispose_list(&freeable);
return freed;
}
diff --git a/fs/super.c b/fs/super.c
index 9d2f2e9..9049110 100644
--- a/fs/super.c
+++ b/fs/super.c
@@ -77,14 +77,13 @@ static long super_cache_scan(struct shrinker *shrink, struct shrink_control *sc)
if (sb->s_op && sb->s_op->nr_cached_objects)
fs_objects = sb->s_op->nr_cached_objects(sb);
- total_objects = sb->s_nr_dentry_unused +
- sb->s_nr_inodes_unused + fs_objects + 1;
+ inodes = list_lru_count(&sb->s_inode_lru);
+ total_objects = sb->s_nr_dentry_unused + inodes + fs_objects + 1;
/* proportion the scan between the caches */
dentries = mult_frac(sc->nr_to_scan, sb->s_nr_dentry_unused,
total_objects);
- inodes = mult_frac(sc->nr_to_scan, sb->s_nr_inodes_unused,
- total_objects);
+ inodes = mult_frac(sc->nr_to_scan, inodes, total_objects);
/*
* prune the dcache first as the icache is pinned by it, then
@@ -117,7 +116,7 @@ static long super_cache_count(struct shrinker *shrink, struct shrink_control *sc
total_objects = sb->s_op->nr_cached_objects(sb);
total_objects += sb->s_nr_dentry_unused;
- total_objects += sb->s_nr_inodes_unused;
+ total_objects += list_lru_count(&sb->s_inode_lru);
total_objects = vfs_pressure_ratio(total_objects);
drop_super(sb);
@@ -198,8 +197,7 @@ static struct super_block *alloc_super(struct file_system_type *type, int flags)
INIT_LIST_HEAD(&s->s_inodes);
INIT_LIST_HEAD(&s->s_dentry_lru);
spin_lock_init(&s->s_dentry_lru_lock);
- INIT_LIST_HEAD(&s->s_inode_lru);
- spin_lock_init(&s->s_inode_lru_lock);
+ list_lru_init(&s->s_inode_lru);
INIT_LIST_HEAD(&s->s_mounts);
init_rwsem(&s->s_umount);
lockdep_set_class(&s->s_umount, &type->s_umount_key);
diff --git a/include/linux/fs.h b/include/linux/fs.h
index f5eabf9..4442613 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -10,6 +10,7 @@
#include <linux/stat.h>
#include <linux/cache.h>
#include <linux/list.h>
+#include <linux/list_lru.h>
#include <linux/radix-tree.h>
#include <linux/rbtree.h>
#include <linux/init.h>
@@ -1269,10 +1270,7 @@ struct super_block {
struct list_head s_dentry_lru; /* unused dentry lru */
int s_nr_dentry_unused; /* # of dentry on lru */
- /* s_inode_lru_lock protects s_inode_lru and s_nr_inodes_unused */
- spinlock_t s_inode_lru_lock ____cacheline_aligned_in_smp;
- struct list_head s_inode_lru; /* unused inode lru */
- int s_nr_inodes_unused; /* # of inodes on lru */
+ struct list_lru s_inode_lru ____cacheline_aligned_in_smp;
struct block_device *s_bdev;
struct backing_dev_info *s_bdi;
--
1.8.1.4
^ permalink raw reply related [flat|nested] 151+ messages in thread* [PATCH v6 08/31] inode: convert inode lru list to generic lru list code.
@ 2013-05-12 18:13 ` Glauber Costa
0 siblings, 0 replies; 151+ messages in thread
From: Glauber Costa @ 2013-05-12 18:13 UTC (permalink / raw)
To: linux-mm
Cc: cgroups, Andrew Morton, Greg Thelen, kamezawa.hiroyu,
Michal Hocko, Johannes Weiner, linux-fsdevel, Dave Chinner,
Dave Chinner, Glauber Costa
From: Dave Chinner <dchinner@redhat.com>
[ glommer: adapted for new LRU return codes ]
Signed-off-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Glauber Costa <glommer@openvz.org>
---
fs/inode.c | 175 +++++++++++++++++++++--------------------------------
fs/super.c | 12 ++--
include/linux/fs.h | 6 +-
3 files changed, 77 insertions(+), 116 deletions(-)
diff --git a/fs/inode.c b/fs/inode.c
index 730aea7..ff66f49 100644
--- a/fs/inode.c
+++ b/fs/inode.c
@@ -17,6 +17,7 @@
#include <linux/prefetch.h>
#include <linux/buffer_head.h> /* for inode_has_buffers */
#include <linux/ratelimit.h>
+#include <linux/list_lru.h>
#include "internal.h"
/*
@@ -24,7 +25,7 @@
*
* inode->i_lock protects:
* inode->i_state, inode->i_hash, __iget()
- * inode->i_sb->s_inode_lru_lock protects:
+ * Inode LRU list locks protect:
* inode->i_sb->s_inode_lru, inode->i_lru
* inode_sb_list_lock protects:
* sb->s_inodes, inode->i_sb_list
@@ -37,7 +38,7 @@
*
* inode_sb_list_lock
* inode->i_lock
- * inode->i_sb->s_inode_lru_lock
+ * Inode LRU list locks
*
* bdi->wb.list_lock
* inode->i_lock
@@ -399,13 +400,8 @@ EXPORT_SYMBOL(ihold);
static void inode_lru_list_add(struct inode *inode)
{
- spin_lock(&inode->i_sb->s_inode_lru_lock);
- if (list_empty(&inode->i_lru)) {
- list_add(&inode->i_lru, &inode->i_sb->s_inode_lru);
- inode->i_sb->s_nr_inodes_unused++;
+ if (list_lru_add(&inode->i_sb->s_inode_lru, &inode->i_lru))
this_cpu_inc(nr_unused);
- }
- spin_unlock(&inode->i_sb->s_inode_lru_lock);
}
/*
@@ -423,13 +419,9 @@ void inode_add_lru(struct inode *inode)
static void inode_lru_list_del(struct inode *inode)
{
- spin_lock(&inode->i_sb->s_inode_lru_lock);
- if (!list_empty(&inode->i_lru)) {
- list_del_init(&inode->i_lru);
- inode->i_sb->s_nr_inodes_unused--;
+
+ if (list_lru_del(&inode->i_sb->s_inode_lru, &inode->i_lru))
this_cpu_dec(nr_unused);
- }
- spin_unlock(&inode->i_sb->s_inode_lru_lock);
}
/**
@@ -673,24 +665,8 @@ int invalidate_inodes(struct super_block *sb, bool kill_dirty)
return busy;
}
-static int can_unuse(struct inode *inode)
-{
- if (inode->i_state & ~I_REFERENCED)
- return 0;
- if (inode_has_buffers(inode))
- return 0;
- if (atomic_read(&inode->i_count))
- return 0;
- if (inode->i_data.nrpages)
- return 0;
- return 1;
-}
-
/*
- * Walk the superblock inode LRU for freeable inodes and attempt to free them.
- * This is called from the superblock shrinker function with a number of inodes
- * to trim from the LRU. Inodes to be freed are moved to a temporary list and
- * then are freed outside inode_lock by dispose_list().
+ * Isolate the inode from the LRU in preparation for freeing it.
*
* Any inodes which are pinned purely because of attached pagecache have their
* pagecache removed. If the inode has metadata buffers attached to
@@ -704,90 +680,79 @@ static int can_unuse(struct inode *inode)
* LRU does not have strict ordering. Hence we don't want to reclaim inodes
* with this flag set because they are the inodes that are out of order.
*/
-long prune_icache_sb(struct super_block *sb, unsigned long nr_to_scan)
+static enum lru_status
+inode_lru_isolate(struct list_head *item, spinlock_t *lru_lock, void *arg)
{
- LIST_HEAD(freeable);
- long nr_scanned;
- long freed = 0;
- unsigned long reap = 0;
+ struct list_head *freeable = arg;
+ struct inode *inode = container_of(item, struct inode, i_lru);
- spin_lock(&sb->s_inode_lru_lock);
- for (nr_scanned = nr_to_scan; nr_scanned >= 0; nr_scanned--) {
- struct inode *inode;
+ /*
+ * we are inverting the lru lock/inode->i_lock here, so use a trylock.
+ * If we fail to get the lock, just skip it.
+ */
+ if (!spin_trylock(&inode->i_lock))
+ return LRU_SKIP;
- if (list_empty(&sb->s_inode_lru))
- break;
+ /*
+ * Referenced or dirty inodes are still in use. Give them another pass
+ * through the LRU as we canot reclaim them now.
+ */
+ if (atomic_read(&inode->i_count) ||
+ (inode->i_state & ~I_REFERENCED)) {
+ list_del_init(&inode->i_lru);
+ spin_unlock(&inode->i_lock);
+ this_cpu_dec(nr_unused);
+ return LRU_REMOVED;
+ }
- inode = list_entry(sb->s_inode_lru.prev, struct inode, i_lru);
+ /* recently referenced inodes get one more pass */
+ if (inode->i_state & I_REFERENCED) {
+ inode->i_state &= ~I_REFERENCED;
+ spin_unlock(&inode->i_lock);
+ return LRU_ROTATE;
+ }
- /*
- * we are inverting the sb->s_inode_lru_lock/inode->i_lock here,
- * so use a trylock. If we fail to get the lock, just move the
- * inode to the back of the list so we don't spin on it.
- */
- if (!spin_trylock(&inode->i_lock)) {
- list_move(&inode->i_lru, &sb->s_inode_lru);
- continue;
+ if (inode_has_buffers(inode) || inode->i_data.nrpages) {
+ __iget(inode);
+ spin_unlock(&inode->i_lock);
+ spin_unlock(lru_lock);
+ if (remove_inode_buffers(inode)) {
+ unsigned long reap;
+ reap = invalidate_mapping_pages(&inode->i_data, 0, -1);
+ if (current_is_kswapd())
+ __count_vm_events(KSWAPD_INODESTEAL, reap);
+ else
+ __count_vm_events(PGINODESTEAL, reap);
+ if (current->reclaim_state)
+ current->reclaim_state->reclaimed_slab += reap;
}
+ iput(inode);
+ spin_lock(lru_lock);
+ return LRU_RETRY;
+ }
- /*
- * Referenced or dirty inodes are still in use. Give them
- * another pass through the LRU as we canot reclaim them now.
- */
- if (atomic_read(&inode->i_count) ||
- (inode->i_state & ~I_REFERENCED)) {
- list_del_init(&inode->i_lru);
- spin_unlock(&inode->i_lock);
- sb->s_nr_inodes_unused--;
- this_cpu_dec(nr_unused);
- continue;
- }
+ WARN_ON(inode->i_state & I_NEW);
+ inode->i_state |= I_FREEING;
+ spin_unlock(&inode->i_lock);
- /* recently referenced inodes get one more pass */
- if (inode->i_state & I_REFERENCED) {
- inode->i_state &= ~I_REFERENCED;
- list_move(&inode->i_lru, &sb->s_inode_lru);
- spin_unlock(&inode->i_lock);
- continue;
- }
- if (inode_has_buffers(inode) || inode->i_data.nrpages) {
- __iget(inode);
- spin_unlock(&inode->i_lock);
- spin_unlock(&sb->s_inode_lru_lock);
- if (remove_inode_buffers(inode))
- reap += invalidate_mapping_pages(&inode->i_data,
- 0, -1);
- iput(inode);
- spin_lock(&sb->s_inode_lru_lock);
-
- if (inode != list_entry(sb->s_inode_lru.next,
- struct inode, i_lru))
- continue; /* wrong inode or list_empty */
- /* avoid lock inversions with trylock */
- if (!spin_trylock(&inode->i_lock))
- continue;
- if (!can_unuse(inode)) {
- spin_unlock(&inode->i_lock);
- continue;
- }
- }
- WARN_ON(inode->i_state & I_NEW);
- inode->i_state |= I_FREEING;
- spin_unlock(&inode->i_lock);
+ list_move(&inode->i_lru, freeable);
+ this_cpu_dec(nr_unused);
+ return LRU_REMOVED;
+}
- list_move(&inode->i_lru, &freeable);
- sb->s_nr_inodes_unused--;
- this_cpu_dec(nr_unused);
- freed++;
- }
- if (current_is_kswapd())
- __count_vm_events(KSWAPD_INODESTEAL, reap);
- else
- __count_vm_events(PGINODESTEAL, reap);
- spin_unlock(&sb->s_inode_lru_lock);
- if (current->reclaim_state)
- current->reclaim_state->reclaimed_slab += reap;
+/*
+ * Walk the superblock inode LRU for freeable inodes and attempt to free them.
+ * This is called from the superblock shrinker function with a number of inodes
+ * to trim from the LRU. Inodes to be freed are moved to a temporary list and
+ * then are freed outside inode_lock by dispose_list().
+ */
+long prune_icache_sb(struct super_block *sb, unsigned long nr_to_scan)
+{
+ LIST_HEAD(freeable);
+ long freed;
+ freed = list_lru_walk(&sb->s_inode_lru, inode_lru_isolate,
+ &freeable, nr_to_scan);
dispose_list(&freeable);
return freed;
}
diff --git a/fs/super.c b/fs/super.c
index 9d2f2e9..9049110 100644
--- a/fs/super.c
+++ b/fs/super.c
@@ -77,14 +77,13 @@ static long super_cache_scan(struct shrinker *shrink, struct shrink_control *sc)
if (sb->s_op && sb->s_op->nr_cached_objects)
fs_objects = sb->s_op->nr_cached_objects(sb);
- total_objects = sb->s_nr_dentry_unused +
- sb->s_nr_inodes_unused + fs_objects + 1;
+ inodes = list_lru_count(&sb->s_inode_lru);
+ total_objects = sb->s_nr_dentry_unused + inodes + fs_objects + 1;
/* proportion the scan between the caches */
dentries = mult_frac(sc->nr_to_scan, sb->s_nr_dentry_unused,
total_objects);
- inodes = mult_frac(sc->nr_to_scan, sb->s_nr_inodes_unused,
- total_objects);
+ inodes = mult_frac(sc->nr_to_scan, inodes, total_objects);
/*
* prune the dcache first as the icache is pinned by it, then
@@ -117,7 +116,7 @@ static long super_cache_count(struct shrinker *shrink, struct shrink_control *sc
total_objects = sb->s_op->nr_cached_objects(sb);
total_objects += sb->s_nr_dentry_unused;
- total_objects += sb->s_nr_inodes_unused;
+ total_objects += list_lru_count(&sb->s_inode_lru);
total_objects = vfs_pressure_ratio(total_objects);
drop_super(sb);
@@ -198,8 +197,7 @@ static struct super_block *alloc_super(struct file_system_type *type, int flags)
INIT_LIST_HEAD(&s->s_inodes);
INIT_LIST_HEAD(&s->s_dentry_lru);
spin_lock_init(&s->s_dentry_lru_lock);
- INIT_LIST_HEAD(&s->s_inode_lru);
- spin_lock_init(&s->s_inode_lru_lock);
+ list_lru_init(&s->s_inode_lru);
INIT_LIST_HEAD(&s->s_mounts);
init_rwsem(&s->s_umount);
lockdep_set_class(&s->s_umount, &type->s_umount_key);
diff --git a/include/linux/fs.h b/include/linux/fs.h
index f5eabf9..4442613 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -10,6 +10,7 @@
#include <linux/stat.h>
#include <linux/cache.h>
#include <linux/list.h>
+#include <linux/list_lru.h>
#include <linux/radix-tree.h>
#include <linux/rbtree.h>
#include <linux/init.h>
@@ -1269,10 +1270,7 @@ struct super_block {
struct list_head s_dentry_lru; /* unused dentry lru */
int s_nr_dentry_unused; /* # of dentry on lru */
- /* s_inode_lru_lock protects s_inode_lru and s_nr_inodes_unused */
- spinlock_t s_inode_lru_lock ____cacheline_aligned_in_smp;
- struct list_head s_inode_lru; /* unused inode lru */
- int s_nr_inodes_unused; /* # of inodes on lru */
+ struct list_lru s_inode_lru ____cacheline_aligned_in_smp;
struct block_device *s_bdev;
struct backing_dev_info *s_bdi;
--
1.8.1.4
--
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^ permalink raw reply related [flat|nested] 151+ messages in thread
* [PATCH v6 09/31] dcache: convert to use new lru list infrastructure
2013-05-12 18:13 ` Glauber Costa
(?)
@ 2013-05-12 18:13 ` Glauber Costa
-1 siblings, 0 replies; 151+ messages in thread
From: Glauber Costa @ 2013-05-12 18:13 UTC (permalink / raw)
To: linux-mm
Cc: cgroups, Andrew Morton, Greg Thelen, kamezawa.hiroyu,
Michal Hocko, Johannes Weiner, linux-fsdevel, Dave Chinner,
Dave Chinner, Glauber Costa
From: Dave Chinner <dchinner@redhat.com>
[ glommer: don't reintroduce double decrement of nr_unused_dentries,
adapted for new LRU return codes ]
Signed-off-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Glauber Costa <glommer@openvz.org>
---
fs/dcache.c | 180 +++++++++++++++++++++++------------------------------
fs/super.c | 11 ++--
include/linux/fs.h | 15 +++--
3 files changed, 91 insertions(+), 115 deletions(-)
diff --git a/fs/dcache.c b/fs/dcache.c
index dc0069c..ba14661 100644
--- a/fs/dcache.c
+++ b/fs/dcache.c
@@ -37,6 +37,7 @@
#include <linux/rculist_bl.h>
#include <linux/prefetch.h>
#include <linux/ratelimit.h>
+#include <linux/list_lru.h>
#include "internal.h"
#include "mount.h"
@@ -319,20 +320,8 @@ static void dentry_unlink_inode(struct dentry * dentry)
*/
static void dentry_lru_add(struct dentry *dentry)
{
- if (list_empty(&dentry->d_lru)) {
- spin_lock(&dentry->d_sb->s_dentry_lru_lock);
- list_add(&dentry->d_lru, &dentry->d_sb->s_dentry_lru);
- dentry->d_sb->s_nr_dentry_unused++;
+ if (list_lru_add(&dentry->d_sb->s_dentry_lru, &dentry->d_lru))
this_cpu_inc(nr_dentry_unused);
- spin_unlock(&dentry->d_sb->s_dentry_lru_lock);
- }
-}
-
-static void __dentry_lru_del(struct dentry *dentry)
-{
- list_del_init(&dentry->d_lru);
- dentry->d_sb->s_nr_dentry_unused--;
- this_cpu_dec(nr_dentry_unused);
}
/*
@@ -342,11 +331,8 @@ static void dentry_lru_del(struct dentry *dentry)
{
BUG_ON(dentry->d_flags & DCACHE_SHRINK_LIST);
- if (!list_empty(&dentry->d_lru)) {
- spin_lock(&dentry->d_sb->s_dentry_lru_lock);
- __dentry_lru_del(dentry);
- spin_unlock(&dentry->d_sb->s_dentry_lru_lock);
- }
+ if (list_lru_del(&dentry->d_sb->s_dentry_lru, &dentry->d_lru))
+ this_cpu_dec(nr_dentry_unused);
}
static void dentry_lru_prune(struct dentry *dentry)
@@ -358,32 +344,13 @@ static void dentry_lru_prune(struct dentry *dentry)
if (dentry->d_flags & DCACHE_OP_PRUNE)
dentry->d_op->d_prune(dentry);
- if (list_empty(&dentry->d_lru))
- return;
-
- if ((dentry->d_flags & DCACHE_SHRINK_LIST)) {
+ if (!list_empty(&dentry->d_lru) &&
+ (dentry->d_flags & DCACHE_SHRINK_LIST))
list_del_init(&dentry->d_lru);
- dentry->d_flags &= ~DCACHE_SHRINK_LIST;
- } else {
- spin_lock(&dentry->d_sb->s_dentry_lru_lock);
- __dentry_lru_del(dentry);
- spin_unlock(&dentry->d_sb->s_dentry_lru_lock);
- }
-}
-
-static void dentry_lru_move_list(struct dentry *dentry, struct list_head *list)
-{
- BUG_ON(dentry->d_flags & DCACHE_SHRINK_LIST);
-
- spin_lock(&dentry->d_sb->s_dentry_lru_lock);
- if (list_empty(&dentry->d_lru)) {
- list_add_tail(&dentry->d_lru, list);
- } else {
- list_move_tail(&dentry->d_lru, list);
- dentry->d_sb->s_nr_dentry_unused--;
+ else if (list_lru_del(&dentry->d_sb->s_dentry_lru, &dentry->d_lru))
this_cpu_dec(nr_dentry_unused);
- }
- spin_unlock(&dentry->d_sb->s_dentry_lru_lock);
+
+ dentry->d_flags &= ~DCACHE_SHRINK_LIST;
}
/**
@@ -844,12 +811,72 @@ static void shrink_dentry_list(struct list_head *list)
rcu_read_unlock();
}
+static enum lru_status
+dentry_lru_isolate(struct list_head *item, spinlock_t *lru_lock, void *arg)
+{
+ struct list_head *freeable = arg;
+ struct dentry *dentry = container_of(item, struct dentry, d_lru);
+
+
+ /*
+ * we are inverting the lru lock/dentry->d_lock here,
+ * so use a trylock. If we fail to get the lock, just skip
+ * it
+ */
+ if (!spin_trylock(&dentry->d_lock))
+ return LRU_SKIP;
+
+ /*
+ * Referenced dentries are still in use. If they have active
+ * counts, just remove them from the LRU. Otherwise give them
+ * another pass through the LRU.
+ */
+ if (dentry->d_count) {
+ list_del_init(&dentry->d_lru);
+ spin_unlock(&dentry->d_lock);
+ return LRU_REMOVED;
+ }
+
+ if (dentry->d_flags & DCACHE_REFERENCED) {
+ dentry->d_flags &= ~DCACHE_REFERENCED;
+ spin_unlock(&dentry->d_lock);
+
+ /*
+ * The list move itself will be made by the common LRU code. At
+ * this point, we've dropped the dentry->d_lock but keep the
+ * lru lock. This is safe to do, since every list movement is
+ * protected by the lru lock even if both locks are held.
+ *
+ * This is guaranteed by the fact that all LRU management
+ * functions are intermediated by the LRU API calls like
+ * list_lru_add and list_lru_del. List movement in this file
+ * only ever occur through this functions or through callbacks
+ * like this one, that are called from the LRU API.
+ *
+ * The only exceptions to this are functions like
+ * shrink_dentry_list, and code that first checks for the
+ * DCACHE_SHRINK_LIST flag. Those are guaranteed to be
+ * operating only with stack provided lists after they are
+ * properly isolated from the main list. It is thus, always a
+ * local access.
+ */
+ return LRU_ROTATE;
+ }
+
+ dentry->d_flags |= DCACHE_SHRINK_LIST;
+ list_move_tail(&dentry->d_lru, freeable);
+ this_cpu_dec(nr_dentry_unused);
+ spin_unlock(&dentry->d_lock);
+
+ return LRU_REMOVED;
+}
+
/**
* prune_dcache_sb - shrink the dcache
* @sb: superblock
- * @count: number of entries to try to free
+ * @nr_to_scan : number of entries to try to free
*
- * Attempt to shrink the superblock dcache LRU by @count entries. This is
+ * Attempt to shrink the superblock dcache LRU by @nr_to_scan entries. This is
* done when we need more memory an called from the superblock shrinker
* function.
*
@@ -858,45 +885,12 @@ static void shrink_dentry_list(struct list_head *list)
*/
long prune_dcache_sb(struct super_block *sb, unsigned long nr_to_scan)
{
- struct dentry *dentry;
- LIST_HEAD(referenced);
- LIST_HEAD(tmp);
- long freed = 0;
-
-relock:
- spin_lock(&sb->s_dentry_lru_lock);
- while (!list_empty(&sb->s_dentry_lru)) {
- dentry = list_entry(sb->s_dentry_lru.prev,
- struct dentry, d_lru);
- BUG_ON(dentry->d_sb != sb);
-
- if (!spin_trylock(&dentry->d_lock)) {
- spin_unlock(&sb->s_dentry_lru_lock);
- cpu_relax();
- goto relock;
- }
-
- if (dentry->d_flags & DCACHE_REFERENCED) {
- dentry->d_flags &= ~DCACHE_REFERENCED;
- list_move(&dentry->d_lru, &referenced);
- spin_unlock(&dentry->d_lock);
- } else {
- list_move_tail(&dentry->d_lru, &tmp);
- dentry->d_flags |= DCACHE_SHRINK_LIST;
- this_cpu_dec(nr_dentry_unused);
- sb->s_nr_dentry_unused--;
- spin_unlock(&dentry->d_lock);
- freed++;
- if (!--nr_to_scan)
- break;
- }
- cond_resched_lock(&sb->s_dentry_lru_lock);
- }
- if (!list_empty(&referenced))
- list_splice(&referenced, &sb->s_dentry_lru);
- spin_unlock(&sb->s_dentry_lru_lock);
+ LIST_HEAD(dispose);
+ long freed;
- shrink_dentry_list(&tmp);
+ freed = list_lru_walk(&sb->s_dentry_lru, dentry_lru_isolate,
+ &dispose, nr_to_scan);
+ shrink_dentry_list(&dispose);
return freed;
}
@@ -930,24 +924,7 @@ shrink_dcache_list(
*/
void shrink_dcache_sb(struct super_block *sb)
{
- LIST_HEAD(tmp);
-
- spin_lock(&sb->s_dentry_lru_lock);
- while (!list_empty(&sb->s_dentry_lru)) {
- list_splice_init(&sb->s_dentry_lru, &tmp);
-
- /*
- * account for removal here so we don't need to handle it later
- * even though the dentry is no longer on the lru list.
- */
- this_cpu_sub(nr_dentry_unused, sb->s_nr_dentry_unused);
- sb->s_nr_dentry_unused = 0;
-
- spin_unlock(&sb->s_dentry_lru_lock);
- shrink_dcache_list(&tmp);
- spin_lock(&sb->s_dentry_lru_lock);
- }
- spin_unlock(&sb->s_dentry_lru_lock);
+ list_lru_dispose_all(&sb->s_dentry_lru, shrink_dcache_list);
}
EXPORT_SYMBOL(shrink_dcache_sb);
@@ -1213,7 +1190,8 @@ resume:
if (dentry->d_count) {
dentry_lru_del(dentry);
} else if (!(dentry->d_flags & DCACHE_SHRINK_LIST)) {
- dentry_lru_move_list(dentry, dispose);
+ dentry_lru_del(dentry);
+ list_add_tail(&dentry->d_lru, dispose);
dentry->d_flags |= DCACHE_SHRINK_LIST;
found++;
}
diff --git a/fs/super.c b/fs/super.c
index 9049110..66f5cde 100644
--- a/fs/super.c
+++ b/fs/super.c
@@ -78,11 +78,11 @@ static long super_cache_scan(struct shrinker *shrink, struct shrink_control *sc)
fs_objects = sb->s_op->nr_cached_objects(sb);
inodes = list_lru_count(&sb->s_inode_lru);
- total_objects = sb->s_nr_dentry_unused + inodes + fs_objects + 1;
+ dentries = list_lru_count(&sb->s_dentry_lru);
+ total_objects = dentries + inodes + fs_objects + 1;
/* proportion the scan between the caches */
- dentries = mult_frac(sc->nr_to_scan, sb->s_nr_dentry_unused,
- total_objects);
+ dentries = mult_frac(sc->nr_to_scan, dentries, total_objects);
inodes = mult_frac(sc->nr_to_scan, inodes, total_objects);
/*
@@ -115,7 +115,7 @@ static long super_cache_count(struct shrinker *shrink, struct shrink_control *sc
if (sb->s_op && sb->s_op->nr_cached_objects)
total_objects = sb->s_op->nr_cached_objects(sb);
- total_objects += sb->s_nr_dentry_unused;
+ total_objects += list_lru_count(&sb->s_dentry_lru);
total_objects += list_lru_count(&sb->s_inode_lru);
total_objects = vfs_pressure_ratio(total_objects);
@@ -195,8 +195,7 @@ static struct super_block *alloc_super(struct file_system_type *type, int flags)
INIT_HLIST_NODE(&s->s_instances);
INIT_HLIST_BL_HEAD(&s->s_anon);
INIT_LIST_HEAD(&s->s_inodes);
- INIT_LIST_HEAD(&s->s_dentry_lru);
- spin_lock_init(&s->s_dentry_lru_lock);
+ list_lru_init(&s->s_dentry_lru);
list_lru_init(&s->s_inode_lru);
INIT_LIST_HEAD(&s->s_mounts);
init_rwsem(&s->s_umount);
diff --git a/include/linux/fs.h b/include/linux/fs.h
index 4442613..02b3612 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -1264,14 +1264,6 @@ struct super_block {
struct list_head s_files;
#endif
struct list_head s_mounts; /* list of mounts; _not_ for fs use */
-
- /* s_dentry_lru_lock protects s_dentry_lru and s_nr_dentry_unused */
- spinlock_t s_dentry_lru_lock ____cacheline_aligned_in_smp;
- struct list_head s_dentry_lru; /* unused dentry lru */
- int s_nr_dentry_unused; /* # of dentry on lru */
-
- struct list_lru s_inode_lru ____cacheline_aligned_in_smp;
-
struct block_device *s_bdev;
struct backing_dev_info *s_bdi;
struct mtd_info *s_mtd;
@@ -1322,6 +1314,13 @@ struct super_block {
/* Being remounted read-only */
int s_readonly_remount;
+
+ /*
+ * Keep the lru lists last in the structure so they always sit on their
+ * own individual cachelines.
+ */
+ struct list_lru s_dentry_lru ____cacheline_aligned_in_smp;
+ struct list_lru s_inode_lru ____cacheline_aligned_in_smp;
};
extern struct timespec current_fs_time(struct super_block *sb);
--
1.8.1.4
^ permalink raw reply related [flat|nested] 151+ messages in thread* [PATCH v6 09/31] dcache: convert to use new lru list infrastructure
@ 2013-05-12 18:13 ` Glauber Costa
0 siblings, 0 replies; 151+ messages in thread
From: Glauber Costa @ 2013-05-12 18:13 UTC (permalink / raw)
To: linux-mm
Cc: cgroups, Andrew Morton, Greg Thelen, kamezawa.hiroyu,
Michal Hocko, Johannes Weiner, linux-fsdevel, Dave Chinner,
Dave Chinner, Glauber Costa
From: Dave Chinner <dchinner@redhat.com>
[ glommer: don't reintroduce double decrement of nr_unused_dentries,
adapted for new LRU return codes ]
Signed-off-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Glauber Costa <glommer@openvz.org>
---
fs/dcache.c | 180 +++++++++++++++++++++++------------------------------
fs/super.c | 11 ++--
include/linux/fs.h | 15 +++--
3 files changed, 91 insertions(+), 115 deletions(-)
diff --git a/fs/dcache.c b/fs/dcache.c
index dc0069c..ba14661 100644
--- a/fs/dcache.c
+++ b/fs/dcache.c
@@ -37,6 +37,7 @@
#include <linux/rculist_bl.h>
#include <linux/prefetch.h>
#include <linux/ratelimit.h>
+#include <linux/list_lru.h>
#include "internal.h"
#include "mount.h"
@@ -319,20 +320,8 @@ static void dentry_unlink_inode(struct dentry * dentry)
*/
static void dentry_lru_add(struct dentry *dentry)
{
- if (list_empty(&dentry->d_lru)) {
- spin_lock(&dentry->d_sb->s_dentry_lru_lock);
- list_add(&dentry->d_lru, &dentry->d_sb->s_dentry_lru);
- dentry->d_sb->s_nr_dentry_unused++;
+ if (list_lru_add(&dentry->d_sb->s_dentry_lru, &dentry->d_lru))
this_cpu_inc(nr_dentry_unused);
- spin_unlock(&dentry->d_sb->s_dentry_lru_lock);
- }
-}
-
-static void __dentry_lru_del(struct dentry *dentry)
-{
- list_del_init(&dentry->d_lru);
- dentry->d_sb->s_nr_dentry_unused--;
- this_cpu_dec(nr_dentry_unused);
}
/*
@@ -342,11 +331,8 @@ static void dentry_lru_del(struct dentry *dentry)
{
BUG_ON(dentry->d_flags & DCACHE_SHRINK_LIST);
- if (!list_empty(&dentry->d_lru)) {
- spin_lock(&dentry->d_sb->s_dentry_lru_lock);
- __dentry_lru_del(dentry);
- spin_unlock(&dentry->d_sb->s_dentry_lru_lock);
- }
+ if (list_lru_del(&dentry->d_sb->s_dentry_lru, &dentry->d_lru))
+ this_cpu_dec(nr_dentry_unused);
}
static void dentry_lru_prune(struct dentry *dentry)
@@ -358,32 +344,13 @@ static void dentry_lru_prune(struct dentry *dentry)
if (dentry->d_flags & DCACHE_OP_PRUNE)
dentry->d_op->d_prune(dentry);
- if (list_empty(&dentry->d_lru))
- return;
-
- if ((dentry->d_flags & DCACHE_SHRINK_LIST)) {
+ if (!list_empty(&dentry->d_lru) &&
+ (dentry->d_flags & DCACHE_SHRINK_LIST))
list_del_init(&dentry->d_lru);
- dentry->d_flags &= ~DCACHE_SHRINK_LIST;
- } else {
- spin_lock(&dentry->d_sb->s_dentry_lru_lock);
- __dentry_lru_del(dentry);
- spin_unlock(&dentry->d_sb->s_dentry_lru_lock);
- }
-}
-
-static void dentry_lru_move_list(struct dentry *dentry, struct list_head *list)
-{
- BUG_ON(dentry->d_flags & DCACHE_SHRINK_LIST);
-
- spin_lock(&dentry->d_sb->s_dentry_lru_lock);
- if (list_empty(&dentry->d_lru)) {
- list_add_tail(&dentry->d_lru, list);
- } else {
- list_move_tail(&dentry->d_lru, list);
- dentry->d_sb->s_nr_dentry_unused--;
+ else if (list_lru_del(&dentry->d_sb->s_dentry_lru, &dentry->d_lru))
this_cpu_dec(nr_dentry_unused);
- }
- spin_unlock(&dentry->d_sb->s_dentry_lru_lock);
+
+ dentry->d_flags &= ~DCACHE_SHRINK_LIST;
}
/**
@@ -844,12 +811,72 @@ static void shrink_dentry_list(struct list_head *list)
rcu_read_unlock();
}
+static enum lru_status
+dentry_lru_isolate(struct list_head *item, spinlock_t *lru_lock, void *arg)
+{
+ struct list_head *freeable = arg;
+ struct dentry *dentry = container_of(item, struct dentry, d_lru);
+
+
+ /*
+ * we are inverting the lru lock/dentry->d_lock here,
+ * so use a trylock. If we fail to get the lock, just skip
+ * it
+ */
+ if (!spin_trylock(&dentry->d_lock))
+ return LRU_SKIP;
+
+ /*
+ * Referenced dentries are still in use. If they have active
+ * counts, just remove them from the LRU. Otherwise give them
+ * another pass through the LRU.
+ */
+ if (dentry->d_count) {
+ list_del_init(&dentry->d_lru);
+ spin_unlock(&dentry->d_lock);
+ return LRU_REMOVED;
+ }
+
+ if (dentry->d_flags & DCACHE_REFERENCED) {
+ dentry->d_flags &= ~DCACHE_REFERENCED;
+ spin_unlock(&dentry->d_lock);
+
+ /*
+ * The list move itself will be made by the common LRU code. At
+ * this point, we've dropped the dentry->d_lock but keep the
+ * lru lock. This is safe to do, since every list movement is
+ * protected by the lru lock even if both locks are held.
+ *
+ * This is guaranteed by the fact that all LRU management
+ * functions are intermediated by the LRU API calls like
+ * list_lru_add and list_lru_del. List movement in this file
+ * only ever occur through this functions or through callbacks
+ * like this one, that are called from the LRU API.
+ *
+ * The only exceptions to this are functions like
+ * shrink_dentry_list, and code that first checks for the
+ * DCACHE_SHRINK_LIST flag. Those are guaranteed to be
+ * operating only with stack provided lists after they are
+ * properly isolated from the main list. It is thus, always a
+ * local access.
+ */
+ return LRU_ROTATE;
+ }
+
+ dentry->d_flags |= DCACHE_SHRINK_LIST;
+ list_move_tail(&dentry->d_lru, freeable);
+ this_cpu_dec(nr_dentry_unused);
+ spin_unlock(&dentry->d_lock);
+
+ return LRU_REMOVED;
+}
+
/**
* prune_dcache_sb - shrink the dcache
* @sb: superblock
- * @count: number of entries to try to free
+ * @nr_to_scan : number of entries to try to free
*
- * Attempt to shrink the superblock dcache LRU by @count entries. This is
+ * Attempt to shrink the superblock dcache LRU by @nr_to_scan entries. This is
* done when we need more memory an called from the superblock shrinker
* function.
*
@@ -858,45 +885,12 @@ static void shrink_dentry_list(struct list_head *list)
*/
long prune_dcache_sb(struct super_block *sb, unsigned long nr_to_scan)
{
- struct dentry *dentry;
- LIST_HEAD(referenced);
- LIST_HEAD(tmp);
- long freed = 0;
-
-relock:
- spin_lock(&sb->s_dentry_lru_lock);
- while (!list_empty(&sb->s_dentry_lru)) {
- dentry = list_entry(sb->s_dentry_lru.prev,
- struct dentry, d_lru);
- BUG_ON(dentry->d_sb != sb);
-
- if (!spin_trylock(&dentry->d_lock)) {
- spin_unlock(&sb->s_dentry_lru_lock);
- cpu_relax();
- goto relock;
- }
-
- if (dentry->d_flags & DCACHE_REFERENCED) {
- dentry->d_flags &= ~DCACHE_REFERENCED;
- list_move(&dentry->d_lru, &referenced);
- spin_unlock(&dentry->d_lock);
- } else {
- list_move_tail(&dentry->d_lru, &tmp);
- dentry->d_flags |= DCACHE_SHRINK_LIST;
- this_cpu_dec(nr_dentry_unused);
- sb->s_nr_dentry_unused--;
- spin_unlock(&dentry->d_lock);
- freed++;
- if (!--nr_to_scan)
- break;
- }
- cond_resched_lock(&sb->s_dentry_lru_lock);
- }
- if (!list_empty(&referenced))
- list_splice(&referenced, &sb->s_dentry_lru);
- spin_unlock(&sb->s_dentry_lru_lock);
+ LIST_HEAD(dispose);
+ long freed;
- shrink_dentry_list(&tmp);
+ freed = list_lru_walk(&sb->s_dentry_lru, dentry_lru_isolate,
+ &dispose, nr_to_scan);
+ shrink_dentry_list(&dispose);
return freed;
}
@@ -930,24 +924,7 @@ shrink_dcache_list(
*/
void shrink_dcache_sb(struct super_block *sb)
{
- LIST_HEAD(tmp);
-
- spin_lock(&sb->s_dentry_lru_lock);
- while (!list_empty(&sb->s_dentry_lru)) {
- list_splice_init(&sb->s_dentry_lru, &tmp);
-
- /*
- * account for removal here so we don't need to handle it later
- * even though the dentry is no longer on the lru list.
- */
- this_cpu_sub(nr_dentry_unused, sb->s_nr_dentry_unused);
- sb->s_nr_dentry_unused = 0;
-
- spin_unlock(&sb->s_dentry_lru_lock);
- shrink_dcache_list(&tmp);
- spin_lock(&sb->s_dentry_lru_lock);
- }
- spin_unlock(&sb->s_dentry_lru_lock);
+ list_lru_dispose_all(&sb->s_dentry_lru, shrink_dcache_list);
}
EXPORT_SYMBOL(shrink_dcache_sb);
@@ -1213,7 +1190,8 @@ resume:
if (dentry->d_count) {
dentry_lru_del(dentry);
} else if (!(dentry->d_flags & DCACHE_SHRINK_LIST)) {
- dentry_lru_move_list(dentry, dispose);
+ dentry_lru_del(dentry);
+ list_add_tail(&dentry->d_lru, dispose);
dentry->d_flags |= DCACHE_SHRINK_LIST;
found++;
}
diff --git a/fs/super.c b/fs/super.c
index 9049110..66f5cde 100644
--- a/fs/super.c
+++ b/fs/super.c
@@ -78,11 +78,11 @@ static long super_cache_scan(struct shrinker *shrink, struct shrink_control *sc)
fs_objects = sb->s_op->nr_cached_objects(sb);
inodes = list_lru_count(&sb->s_inode_lru);
- total_objects = sb->s_nr_dentry_unused + inodes + fs_objects + 1;
+ dentries = list_lru_count(&sb->s_dentry_lru);
+ total_objects = dentries + inodes + fs_objects + 1;
/* proportion the scan between the caches */
- dentries = mult_frac(sc->nr_to_scan, sb->s_nr_dentry_unused,
- total_objects);
+ dentries = mult_frac(sc->nr_to_scan, dentries, total_objects);
inodes = mult_frac(sc->nr_to_scan, inodes, total_objects);
/*
@@ -115,7 +115,7 @@ static long super_cache_count(struct shrinker *shrink, struct shrink_control *sc
if (sb->s_op && sb->s_op->nr_cached_objects)
total_objects = sb->s_op->nr_cached_objects(sb);
- total_objects += sb->s_nr_dentry_unused;
+ total_objects += list_lru_count(&sb->s_dentry_lru);
total_objects += list_lru_count(&sb->s_inode_lru);
total_objects = vfs_pressure_ratio(total_objects);
@@ -195,8 +195,7 @@ static struct super_block *alloc_super(struct file_system_type *type, int flags)
INIT_HLIST_NODE(&s->s_instances);
INIT_HLIST_BL_HEAD(&s->s_anon);
INIT_LIST_HEAD(&s->s_inodes);
- INIT_LIST_HEAD(&s->s_dentry_lru);
- spin_lock_init(&s->s_dentry_lru_lock);
+ list_lru_init(&s->s_dentry_lru);
list_lru_init(&s->s_inode_lru);
INIT_LIST_HEAD(&s->s_mounts);
init_rwsem(&s->s_umount);
diff --git a/include/linux/fs.h b/include/linux/fs.h
index 4442613..02b3612 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -1264,14 +1264,6 @@ struct super_block {
struct list_head s_files;
#endif
struct list_head s_mounts; /* list of mounts; _not_ for fs use */
-
- /* s_dentry_lru_lock protects s_dentry_lru and s_nr_dentry_unused */
- spinlock_t s_dentry_lru_lock ____cacheline_aligned_in_smp;
- struct list_head s_dentry_lru; /* unused dentry lru */
- int s_nr_dentry_unused; /* # of dentry on lru */
-
- struct list_lru s_inode_lru ____cacheline_aligned_in_smp;
-
struct block_device *s_bdev;
struct backing_dev_info *s_bdi;
struct mtd_info *s_mtd;
@@ -1322,6 +1314,13 @@ struct super_block {
/* Being remounted read-only */
int s_readonly_remount;
+
+ /*
+ * Keep the lru lists last in the structure so they always sit on their
+ * own individual cachelines.
+ */
+ struct list_lru s_dentry_lru ____cacheline_aligned_in_smp;
+ struct list_lru s_inode_lru ____cacheline_aligned_in_smp;
};
extern struct timespec current_fs_time(struct super_block *sb);
--
1.8.1.4
^ permalink raw reply related [flat|nested] 151+ messages in thread* [PATCH v6 09/31] dcache: convert to use new lru list infrastructure
@ 2013-05-12 18:13 ` Glauber Costa
0 siblings, 0 replies; 151+ messages in thread
From: Glauber Costa @ 2013-05-12 18:13 UTC (permalink / raw)
To: linux-mm
Cc: cgroups, Andrew Morton, Greg Thelen, kamezawa.hiroyu,
Michal Hocko, Johannes Weiner, linux-fsdevel, Dave Chinner,
Dave Chinner, Glauber Costa
From: Dave Chinner <dchinner@redhat.com>
[ glommer: don't reintroduce double decrement of nr_unused_dentries,
adapted for new LRU return codes ]
Signed-off-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Glauber Costa <glommer@openvz.org>
---
fs/dcache.c | 180 +++++++++++++++++++++++------------------------------
fs/super.c | 11 ++--
include/linux/fs.h | 15 +++--
3 files changed, 91 insertions(+), 115 deletions(-)
diff --git a/fs/dcache.c b/fs/dcache.c
index dc0069c..ba14661 100644
--- a/fs/dcache.c
+++ b/fs/dcache.c
@@ -37,6 +37,7 @@
#include <linux/rculist_bl.h>
#include <linux/prefetch.h>
#include <linux/ratelimit.h>
+#include <linux/list_lru.h>
#include "internal.h"
#include "mount.h"
@@ -319,20 +320,8 @@ static void dentry_unlink_inode(struct dentry * dentry)
*/
static void dentry_lru_add(struct dentry *dentry)
{
- if (list_empty(&dentry->d_lru)) {
- spin_lock(&dentry->d_sb->s_dentry_lru_lock);
- list_add(&dentry->d_lru, &dentry->d_sb->s_dentry_lru);
- dentry->d_sb->s_nr_dentry_unused++;
+ if (list_lru_add(&dentry->d_sb->s_dentry_lru, &dentry->d_lru))
this_cpu_inc(nr_dentry_unused);
- spin_unlock(&dentry->d_sb->s_dentry_lru_lock);
- }
-}
-
-static void __dentry_lru_del(struct dentry *dentry)
-{
- list_del_init(&dentry->d_lru);
- dentry->d_sb->s_nr_dentry_unused--;
- this_cpu_dec(nr_dentry_unused);
}
/*
@@ -342,11 +331,8 @@ static void dentry_lru_del(struct dentry *dentry)
{
BUG_ON(dentry->d_flags & DCACHE_SHRINK_LIST);
- if (!list_empty(&dentry->d_lru)) {
- spin_lock(&dentry->d_sb->s_dentry_lru_lock);
- __dentry_lru_del(dentry);
- spin_unlock(&dentry->d_sb->s_dentry_lru_lock);
- }
+ if (list_lru_del(&dentry->d_sb->s_dentry_lru, &dentry->d_lru))
+ this_cpu_dec(nr_dentry_unused);
}
static void dentry_lru_prune(struct dentry *dentry)
@@ -358,32 +344,13 @@ static void dentry_lru_prune(struct dentry *dentry)
if (dentry->d_flags & DCACHE_OP_PRUNE)
dentry->d_op->d_prune(dentry);
- if (list_empty(&dentry->d_lru))
- return;
-
- if ((dentry->d_flags & DCACHE_SHRINK_LIST)) {
+ if (!list_empty(&dentry->d_lru) &&
+ (dentry->d_flags & DCACHE_SHRINK_LIST))
list_del_init(&dentry->d_lru);
- dentry->d_flags &= ~DCACHE_SHRINK_LIST;
- } else {
- spin_lock(&dentry->d_sb->s_dentry_lru_lock);
- __dentry_lru_del(dentry);
- spin_unlock(&dentry->d_sb->s_dentry_lru_lock);
- }
-}
-
-static void dentry_lru_move_list(struct dentry *dentry, struct list_head *list)
-{
- BUG_ON(dentry->d_flags & DCACHE_SHRINK_LIST);
-
- spin_lock(&dentry->d_sb->s_dentry_lru_lock);
- if (list_empty(&dentry->d_lru)) {
- list_add_tail(&dentry->d_lru, list);
- } else {
- list_move_tail(&dentry->d_lru, list);
- dentry->d_sb->s_nr_dentry_unused--;
+ else if (list_lru_del(&dentry->d_sb->s_dentry_lru, &dentry->d_lru))
this_cpu_dec(nr_dentry_unused);
- }
- spin_unlock(&dentry->d_sb->s_dentry_lru_lock);
+
+ dentry->d_flags &= ~DCACHE_SHRINK_LIST;
}
/**
@@ -844,12 +811,72 @@ static void shrink_dentry_list(struct list_head *list)
rcu_read_unlock();
}
+static enum lru_status
+dentry_lru_isolate(struct list_head *item, spinlock_t *lru_lock, void *arg)
+{
+ struct list_head *freeable = arg;
+ struct dentry *dentry = container_of(item, struct dentry, d_lru);
+
+
+ /*
+ * we are inverting the lru lock/dentry->d_lock here,
+ * so use a trylock. If we fail to get the lock, just skip
+ * it
+ */
+ if (!spin_trylock(&dentry->d_lock))
+ return LRU_SKIP;
+
+ /*
+ * Referenced dentries are still in use. If they have active
+ * counts, just remove them from the LRU. Otherwise give them
+ * another pass through the LRU.
+ */
+ if (dentry->d_count) {
+ list_del_init(&dentry->d_lru);
+ spin_unlock(&dentry->d_lock);
+ return LRU_REMOVED;
+ }
+
+ if (dentry->d_flags & DCACHE_REFERENCED) {
+ dentry->d_flags &= ~DCACHE_REFERENCED;
+ spin_unlock(&dentry->d_lock);
+
+ /*
+ * The list move itself will be made by the common LRU code. At
+ * this point, we've dropped the dentry->d_lock but keep the
+ * lru lock. This is safe to do, since every list movement is
+ * protected by the lru lock even if both locks are held.
+ *
+ * This is guaranteed by the fact that all LRU management
+ * functions are intermediated by the LRU API calls like
+ * list_lru_add and list_lru_del. List movement in this file
+ * only ever occur through this functions or through callbacks
+ * like this one, that are called from the LRU API.
+ *
+ * The only exceptions to this are functions like
+ * shrink_dentry_list, and code that first checks for the
+ * DCACHE_SHRINK_LIST flag. Those are guaranteed to be
+ * operating only with stack provided lists after they are
+ * properly isolated from the main list. It is thus, always a
+ * local access.
+ */
+ return LRU_ROTATE;
+ }
+
+ dentry->d_flags |= DCACHE_SHRINK_LIST;
+ list_move_tail(&dentry->d_lru, freeable);
+ this_cpu_dec(nr_dentry_unused);
+ spin_unlock(&dentry->d_lock);
+
+ return LRU_REMOVED;
+}
+
/**
* prune_dcache_sb - shrink the dcache
* @sb: superblock
- * @count: number of entries to try to free
+ * @nr_to_scan : number of entries to try to free
*
- * Attempt to shrink the superblock dcache LRU by @count entries. This is
+ * Attempt to shrink the superblock dcache LRU by @nr_to_scan entries. This is
* done when we need more memory an called from the superblock shrinker
* function.
*
@@ -858,45 +885,12 @@ static void shrink_dentry_list(struct list_head *list)
*/
long prune_dcache_sb(struct super_block *sb, unsigned long nr_to_scan)
{
- struct dentry *dentry;
- LIST_HEAD(referenced);
- LIST_HEAD(tmp);
- long freed = 0;
-
-relock:
- spin_lock(&sb->s_dentry_lru_lock);
- while (!list_empty(&sb->s_dentry_lru)) {
- dentry = list_entry(sb->s_dentry_lru.prev,
- struct dentry, d_lru);
- BUG_ON(dentry->d_sb != sb);
-
- if (!spin_trylock(&dentry->d_lock)) {
- spin_unlock(&sb->s_dentry_lru_lock);
- cpu_relax();
- goto relock;
- }
-
- if (dentry->d_flags & DCACHE_REFERENCED) {
- dentry->d_flags &= ~DCACHE_REFERENCED;
- list_move(&dentry->d_lru, &referenced);
- spin_unlock(&dentry->d_lock);
- } else {
- list_move_tail(&dentry->d_lru, &tmp);
- dentry->d_flags |= DCACHE_SHRINK_LIST;
- this_cpu_dec(nr_dentry_unused);
- sb->s_nr_dentry_unused--;
- spin_unlock(&dentry->d_lock);
- freed++;
- if (!--nr_to_scan)
- break;
- }
- cond_resched_lock(&sb->s_dentry_lru_lock);
- }
- if (!list_empty(&referenced))
- list_splice(&referenced, &sb->s_dentry_lru);
- spin_unlock(&sb->s_dentry_lru_lock);
+ LIST_HEAD(dispose);
+ long freed;
- shrink_dentry_list(&tmp);
+ freed = list_lru_walk(&sb->s_dentry_lru, dentry_lru_isolate,
+ &dispose, nr_to_scan);
+ shrink_dentry_list(&dispose);
return freed;
}
@@ -930,24 +924,7 @@ shrink_dcache_list(
*/
void shrink_dcache_sb(struct super_block *sb)
{
- LIST_HEAD(tmp);
-
- spin_lock(&sb->s_dentry_lru_lock);
- while (!list_empty(&sb->s_dentry_lru)) {
- list_splice_init(&sb->s_dentry_lru, &tmp);
-
- /*
- * account for removal here so we don't need to handle it later
- * even though the dentry is no longer on the lru list.
- */
- this_cpu_sub(nr_dentry_unused, sb->s_nr_dentry_unused);
- sb->s_nr_dentry_unused = 0;
-
- spin_unlock(&sb->s_dentry_lru_lock);
- shrink_dcache_list(&tmp);
- spin_lock(&sb->s_dentry_lru_lock);
- }
- spin_unlock(&sb->s_dentry_lru_lock);
+ list_lru_dispose_all(&sb->s_dentry_lru, shrink_dcache_list);
}
EXPORT_SYMBOL(shrink_dcache_sb);
@@ -1213,7 +1190,8 @@ resume:
if (dentry->d_count) {
dentry_lru_del(dentry);
} else if (!(dentry->d_flags & DCACHE_SHRINK_LIST)) {
- dentry_lru_move_list(dentry, dispose);
+ dentry_lru_del(dentry);
+ list_add_tail(&dentry->d_lru, dispose);
dentry->d_flags |= DCACHE_SHRINK_LIST;
found++;
}
diff --git a/fs/super.c b/fs/super.c
index 9049110..66f5cde 100644
--- a/fs/super.c
+++ b/fs/super.c
@@ -78,11 +78,11 @@ static long super_cache_scan(struct shrinker *shrink, struct shrink_control *sc)
fs_objects = sb->s_op->nr_cached_objects(sb);
inodes = list_lru_count(&sb->s_inode_lru);
- total_objects = sb->s_nr_dentry_unused + inodes + fs_objects + 1;
+ dentries = list_lru_count(&sb->s_dentry_lru);
+ total_objects = dentries + inodes + fs_objects + 1;
/* proportion the scan between the caches */
- dentries = mult_frac(sc->nr_to_scan, sb->s_nr_dentry_unused,
- total_objects);
+ dentries = mult_frac(sc->nr_to_scan, dentries, total_objects);
inodes = mult_frac(sc->nr_to_scan, inodes, total_objects);
/*
@@ -115,7 +115,7 @@ static long super_cache_count(struct shrinker *shrink, struct shrink_control *sc
if (sb->s_op && sb->s_op->nr_cached_objects)
total_objects = sb->s_op->nr_cached_objects(sb);
- total_objects += sb->s_nr_dentry_unused;
+ total_objects += list_lru_count(&sb->s_dentry_lru);
total_objects += list_lru_count(&sb->s_inode_lru);
total_objects = vfs_pressure_ratio(total_objects);
@@ -195,8 +195,7 @@ static struct super_block *alloc_super(struct file_system_type *type, int flags)
INIT_HLIST_NODE(&s->s_instances);
INIT_HLIST_BL_HEAD(&s->s_anon);
INIT_LIST_HEAD(&s->s_inodes);
- INIT_LIST_HEAD(&s->s_dentry_lru);
- spin_lock_init(&s->s_dentry_lru_lock);
+ list_lru_init(&s->s_dentry_lru);
list_lru_init(&s->s_inode_lru);
INIT_LIST_HEAD(&s->s_mounts);
init_rwsem(&s->s_umount);
diff --git a/include/linux/fs.h b/include/linux/fs.h
index 4442613..02b3612 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -1264,14 +1264,6 @@ struct super_block {
struct list_head s_files;
#endif
struct list_head s_mounts; /* list of mounts; _not_ for fs use */
-
- /* s_dentry_lru_lock protects s_dentry_lru and s_nr_dentry_unused */
- spinlock_t s_dentry_lru_lock ____cacheline_aligned_in_smp;
- struct list_head s_dentry_lru; /* unused dentry lru */
- int s_nr_dentry_unused; /* # of dentry on lru */
-
- struct list_lru s_inode_lru ____cacheline_aligned_in_smp;
-
struct block_device *s_bdev;
struct backing_dev_info *s_bdi;
struct mtd_info *s_mtd;
@@ -1322,6 +1314,13 @@ struct super_block {
/* Being remounted read-only */
int s_readonly_remount;
+
+ /*
+ * Keep the lru lists last in the structure so they always sit on their
+ * own individual cachelines.
+ */
+ struct list_lru s_dentry_lru ____cacheline_aligned_in_smp;
+ struct list_lru s_inode_lru ____cacheline_aligned_in_smp;
};
extern struct timespec current_fs_time(struct super_block *sb);
--
1.8.1.4
--
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^ permalink raw reply related [flat|nested] 151+ messages in thread[parent not found: <1368382432-25462-10-git-send-email-glommer-GEFAQzZX7r8dnm+yROfE0A@public.gmane.org>]
* Re: [PATCH v6 09/31] dcache: convert to use new lru list infrastructure
2013-05-12 18:13 ` Glauber Costa
@ 2013-05-14 6:59 ` Dave Chinner
-1 siblings, 0 replies; 151+ messages in thread
From: Dave Chinner @ 2013-05-14 6:59 UTC (permalink / raw)
To: Glauber Costa
Cc: linux-mm-Bw31MaZKKs3YtjvyW6yDsg, cgroups-u79uwXL29TY76Z2rM5mHXA,
Andrew Morton, Greg Thelen,
kamezawa.hiroyu-+CUm20s59erQFUHtdCDX3A, Michal Hocko,
Johannes Weiner, linux-fsdevel-u79uwXL29TY76Z2rM5mHXA,
Dave Chinner
On Sun, May 12, 2013 at 10:13:30PM +0400, Glauber Costa wrote:
> From: Dave Chinner <dchinner-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>
>
> [ glommer: don't reintroduce double decrement of nr_unused_dentries,
> adapted for new LRU return codes ]
> Signed-off-by: Dave Chinner <dchinner-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>
> Signed-off-by: Glauber Costa <glommer-GEFAQzZX7r8dnm+yROfE0A@public.gmane.org>
> ---
I'm seeing a panic on startup in d_kill() with an invalid d_child
list entry with this patch. I haven't got to the bottom of it yet.
.....
> void shrink_dcache_sb(struct super_block *sb)
> {
> - LIST_HEAD(tmp);
> -
> - spin_lock(&sb->s_dentry_lru_lock);
> - while (!list_empty(&sb->s_dentry_lru)) {
> - list_splice_init(&sb->s_dentry_lru, &tmp);
> -
> - /*
> - * account for removal here so we don't need to handle it later
> - * even though the dentry is no longer on the lru list.
> - */
> - this_cpu_sub(nr_dentry_unused, sb->s_nr_dentry_unused);
> - sb->s_nr_dentry_unused = 0;
> -
> - spin_unlock(&sb->s_dentry_lru_lock);
> - shrink_dcache_list(&tmp);
> - spin_lock(&sb->s_dentry_lru_lock);
> - }
> - spin_unlock(&sb->s_dentry_lru_lock);
> + list_lru_dispose_all(&sb->s_dentry_lru, shrink_dcache_list);
> }
> EXPORT_SYMBOL(shrink_dcache_sb);
And here comes the fun part. This doesn't account for the
dentries that are freed from the superblock here.
So, it needs to be something like:
void shrink_dcache_sb(struct super_block *sb)
{
unsigned long disposed;
disposed = list_lru_dispose_all(&sb->s_dentry_lru,
shrink_dcache_list);
this_cpu_sub(nr_dentry_unused, disposed);
}
But, therein lies a problem. nr_dentry_unused is a 32 bit counter,
and we can return a 64 bit value here. So that means we have to bump
nr_dentry_unused to a long, not an int for these per-cpu counters to
work.
And then there's the problem that the sum of these counters only
uses an int. Which means if we get large numbers of negative values
on different CPU from unmounts, the summation will end up
overflowing and it'll all suck.
So, Glauber, what do you reckon? I've never likes this stupid
hand-rolled per-cpu counter stuff, and it's causing issues. Should
we just convert them to generic per-cpu counters because they are
64bit clean and just handle out-of-range sums in the /proc update
code?
Cheers,
Dave.
--
Dave Chinner
david-FqsqvQoI3Ljby3iVrkZq2A@public.gmane.org
^ permalink raw reply [flat|nested] 151+ messages in thread* Re: [PATCH v6 09/31] dcache: convert to use new lru list infrastructure
@ 2013-05-14 6:59 ` Dave Chinner
0 siblings, 0 replies; 151+ messages in thread
From: Dave Chinner @ 2013-05-14 6:59 UTC (permalink / raw)
To: Glauber Costa
Cc: linux-mm, cgroups, Andrew Morton, Greg Thelen, kamezawa.hiroyu,
Michal Hocko, Johannes Weiner, linux-fsdevel, Dave Chinner
On Sun, May 12, 2013 at 10:13:30PM +0400, Glauber Costa wrote:
> From: Dave Chinner <dchinner@redhat.com>
>
> [ glommer: don't reintroduce double decrement of nr_unused_dentries,
> adapted for new LRU return codes ]
> Signed-off-by: Dave Chinner <dchinner@redhat.com>
> Signed-off-by: Glauber Costa <glommer@openvz.org>
> ---
I'm seeing a panic on startup in d_kill() with an invalid d_child
list entry with this patch. I haven't got to the bottom of it yet.
.....
> void shrink_dcache_sb(struct super_block *sb)
> {
> - LIST_HEAD(tmp);
> -
> - spin_lock(&sb->s_dentry_lru_lock);
> - while (!list_empty(&sb->s_dentry_lru)) {
> - list_splice_init(&sb->s_dentry_lru, &tmp);
> -
> - /*
> - * account for removal here so we don't need to handle it later
> - * even though the dentry is no longer on the lru list.
> - */
> - this_cpu_sub(nr_dentry_unused, sb->s_nr_dentry_unused);
> - sb->s_nr_dentry_unused = 0;
> -
> - spin_unlock(&sb->s_dentry_lru_lock);
> - shrink_dcache_list(&tmp);
> - spin_lock(&sb->s_dentry_lru_lock);
> - }
> - spin_unlock(&sb->s_dentry_lru_lock);
> + list_lru_dispose_all(&sb->s_dentry_lru, shrink_dcache_list);
> }
> EXPORT_SYMBOL(shrink_dcache_sb);
And here comes the fun part. This doesn't account for the
dentries that are freed from the superblock here.
So, it needs to be something like:
void shrink_dcache_sb(struct super_block *sb)
{
unsigned long disposed;
disposed = list_lru_dispose_all(&sb->s_dentry_lru,
shrink_dcache_list);
this_cpu_sub(nr_dentry_unused, disposed);
}
But, therein lies a problem. nr_dentry_unused is a 32 bit counter,
and we can return a 64 bit value here. So that means we have to bump
nr_dentry_unused to a long, not an int for these per-cpu counters to
work.
And then there's the problem that the sum of these counters only
uses an int. Which means if we get large numbers of negative values
on different CPU from unmounts, the summation will end up
overflowing and it'll all suck.
So, Glauber, what do you reckon? I've never likes this stupid
hand-rolled per-cpu counter stuff, and it's causing issues. Should
we just convert them to generic per-cpu counters because they are
64bit clean and just handle out-of-range sums in the /proc update
code?
Cheers,
Dave.
--
Dave Chinner
david@fromorbit.com
--
To unsubscribe, send a message with 'unsubscribe linux-mm' in
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^ permalink raw reply [flat|nested] 151+ messages in thread* Re: [PATCH v6 09/31] dcache: convert to use new lru list infrastructure
2013-05-14 6:59 ` Dave Chinner
@ 2013-05-14 7:50 ` Glauber Costa
-1 siblings, 0 replies; 151+ messages in thread
From: Glauber Costa @ 2013-05-14 7:50 UTC (permalink / raw)
To: Dave Chinner
Cc: Glauber Costa, linux-mm, cgroups, Andrew Morton, Greg Thelen,
kamezawa.hiroyu, Michal Hocko, Johannes Weiner, linux-fsdevel,
Dave Chinner
On 05/14/2013 10:59 AM, Dave Chinner wrote:
> On Sun, May 12, 2013 at 10:13:30PM +0400, Glauber Costa wrote:
>> From: Dave Chinner <dchinner@redhat.com>
>>
>> [ glommer: don't reintroduce double decrement of nr_unused_dentries,
>> adapted for new LRU return codes ]
>> Signed-off-by: Dave Chinner <dchinner@redhat.com>
>> Signed-off-by: Glauber Costa <glommer@openvz.org>
>> ---
>
> I'm seeing a panic on startup in d_kill() with an invalid d_child
> list entry with this patch. I haven't got to the bottom of it yet.
>
> .....
>
>> void shrink_dcache_sb(struct super_block *sb)
>> {
>> - LIST_HEAD(tmp);
>> -
>> - spin_lock(&sb->s_dentry_lru_lock);
>> - while (!list_empty(&sb->s_dentry_lru)) {
>> - list_splice_init(&sb->s_dentry_lru, &tmp);
>> -
>> - /*
>> - * account for removal here so we don't need to handle it later
>> - * even though the dentry is no longer on the lru list.
>> - */
>> - this_cpu_sub(nr_dentry_unused, sb->s_nr_dentry_unused);
>> - sb->s_nr_dentry_unused = 0;
>> -
>> - spin_unlock(&sb->s_dentry_lru_lock);
>> - shrink_dcache_list(&tmp);
>> - spin_lock(&sb->s_dentry_lru_lock);
>> - }
>> - spin_unlock(&sb->s_dentry_lru_lock);
>> + list_lru_dispose_all(&sb->s_dentry_lru, shrink_dcache_list);
>> }
>> EXPORT_SYMBOL(shrink_dcache_sb);
>
> And here comes the fun part. This doesn't account for the
> dentries that are freed from the superblock here.
>
> So, it needs to be something like:
>
> void shrink_dcache_sb(struct super_block *sb)
> {
> unsigned long disposed;
>
> disposed = list_lru_dispose_all(&sb->s_dentry_lru,
> shrink_dcache_list);
>
> this_cpu_sub(nr_dentry_unused, disposed);
> }
>
> But, therein lies a problem. nr_dentry_unused is a 32 bit counter,
> and we can return a 64 bit value here. So that means we have to bump
> nr_dentry_unused to a long, not an int for these per-cpu counters to
> work.
>
> And then there's the problem that the sum of these counters only
> uses an int. Which means if we get large numbers of negative values
> on different CPU from unmounts, the summation will end up
> overflowing and it'll all suck.
>
> So, Glauber, what do you reckon? I've never likes this stupid
> hand-rolled per-cpu counter stuff, and it's causing issues. Should
> we just convert them to generic per-cpu counters because they are
> 64bit clean and just handle out-of-range sums in the /proc update
> code?
>
I am not against it, per se.
But assuming that whoever did it did it for a reason, can't we just
propagate 64 bit quantities everywhere? Moving to long instead of int
should already give us some room, and is actually a sensible thing to
do: There is no reason whatsoever to keep using ints around like this.
--
To unsubscribe, send a message with 'unsubscribe linux-mm' in
the body to majordomo@kvack.org. For more info on Linux MM,
see: http://www.linux-mm.org/ .
Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a>
^ permalink raw reply [flat|nested] 151+ messages in thread* Re: [PATCH v6 09/31] dcache: convert to use new lru list infrastructure
@ 2013-05-14 7:50 ` Glauber Costa
0 siblings, 0 replies; 151+ messages in thread
From: Glauber Costa @ 2013-05-14 7:50 UTC (permalink / raw)
To: Dave Chinner
Cc: Glauber Costa, linux-mm, cgroups, Andrew Morton, Greg Thelen,
kamezawa.hiroyu, Michal Hocko, Johannes Weiner, linux-fsdevel,
Dave Chinner
On 05/14/2013 10:59 AM, Dave Chinner wrote:
> On Sun, May 12, 2013 at 10:13:30PM +0400, Glauber Costa wrote:
>> From: Dave Chinner <dchinner@redhat.com>
>>
>> [ glommer: don't reintroduce double decrement of nr_unused_dentries,
>> adapted for new LRU return codes ]
>> Signed-off-by: Dave Chinner <dchinner@redhat.com>
>> Signed-off-by: Glauber Costa <glommer@openvz.org>
>> ---
>
> I'm seeing a panic on startup in d_kill() with an invalid d_child
> list entry with this patch. I haven't got to the bottom of it yet.
>
> .....
>
>> void shrink_dcache_sb(struct super_block *sb)
>> {
>> - LIST_HEAD(tmp);
>> -
>> - spin_lock(&sb->s_dentry_lru_lock);
>> - while (!list_empty(&sb->s_dentry_lru)) {
>> - list_splice_init(&sb->s_dentry_lru, &tmp);
>> -
>> - /*
>> - * account for removal here so we don't need to handle it later
>> - * even though the dentry is no longer on the lru list.
>> - */
>> - this_cpu_sub(nr_dentry_unused, sb->s_nr_dentry_unused);
>> - sb->s_nr_dentry_unused = 0;
>> -
>> - spin_unlock(&sb->s_dentry_lru_lock);
>> - shrink_dcache_list(&tmp);
>> - spin_lock(&sb->s_dentry_lru_lock);
>> - }
>> - spin_unlock(&sb->s_dentry_lru_lock);
>> + list_lru_dispose_all(&sb->s_dentry_lru, shrink_dcache_list);
>> }
>> EXPORT_SYMBOL(shrink_dcache_sb);
>
> And here comes the fun part. This doesn't account for the
> dentries that are freed from the superblock here.
>
> So, it needs to be something like:
>
> void shrink_dcache_sb(struct super_block *sb)
> {
> unsigned long disposed;
>
> disposed = list_lru_dispose_all(&sb->s_dentry_lru,
> shrink_dcache_list);
>
> this_cpu_sub(nr_dentry_unused, disposed);
> }
>
> But, therein lies a problem. nr_dentry_unused is a 32 bit counter,
> and we can return a 64 bit value here. So that means we have to bump
> nr_dentry_unused to a long, not an int for these per-cpu counters to
> work.
>
> And then there's the problem that the sum of these counters only
> uses an int. Which means if we get large numbers of negative values
> on different CPU from unmounts, the summation will end up
> overflowing and it'll all suck.
>
> So, Glauber, what do you reckon? I've never likes this stupid
> hand-rolled per-cpu counter stuff, and it's causing issues. Should
> we just convert them to generic per-cpu counters because they are
> 64bit clean and just handle out-of-range sums in the /proc update
> code?
>
I am not against it, per se.
But assuming that whoever did it did it for a reason, can't we just
propagate 64 bit quantities everywhere? Moving to long instead of int
should already give us some room, and is actually a sensible thing to
do: There is no reason whatsoever to keep using ints around like this.
--
To unsubscribe, send a message with 'unsubscribe linux-mm' in
the body to majordomo@kvack.org. For more info on Linux MM,
see: http://www.linux-mm.org/ .
Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a>
^ permalink raw reply [flat|nested] 151+ messages in thread
* Re: [PATCH v6 09/31] dcache: convert to use new lru list infrastructure
2013-05-14 6:59 ` Dave Chinner
(?)
@ 2013-05-14 14:01 ` Glauber Costa
-1 siblings, 0 replies; 151+ messages in thread
From: Glauber Costa @ 2013-05-14 14:01 UTC (permalink / raw)
To: Dave Chinner
Cc: Glauber Costa, linux-mm-Bw31MaZKKs3YtjvyW6yDsg,
cgroups-u79uwXL29TY76Z2rM5mHXA, Andrew Morton, Greg Thelen,
kamezawa.hiroyu-+CUm20s59erQFUHtdCDX3A, Michal Hocko,
Johannes Weiner, linux-fsdevel-u79uwXL29TY76Z2rM5mHXA,
Dave Chinner
[-- Attachment #1: Type: text/plain, Size: 2662 bytes --]
On 05/14/2013 10:59 AM, Dave Chinner wrote:
> On Sun, May 12, 2013 at 10:13:30PM +0400, Glauber Costa wrote:
>> From: Dave Chinner <dchinner-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>
>>
>> [ glommer: don't reintroduce double decrement of nr_unused_dentries,
>> adapted for new LRU return codes ]
>> Signed-off-by: Dave Chinner <dchinner-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>
>> Signed-off-by: Glauber Costa <glommer-GEFAQzZX7r8dnm+yROfE0A@public.gmane.org>
>> ---
>
> I'm seeing a panic on startup in d_kill() with an invalid d_child
> list entry with this patch. I haven't got to the bottom of it yet.
>
My wild guess is that your patch does not prune correctly, as I
described in my last message.
> .....
>
>> void shrink_dcache_sb(struct super_block *sb)
>> {
>> - LIST_HEAD(tmp);
>> -
>> - spin_lock(&sb->s_dentry_lru_lock);
>> - while (!list_empty(&sb->s_dentry_lru)) {
>> - list_splice_init(&sb->s_dentry_lru, &tmp);
>> -
>> - /*
>> - * account for removal here so we don't need to handle it later
>> - * even though the dentry is no longer on the lru list.
>> - */
>> - this_cpu_sub(nr_dentry_unused, sb->s_nr_dentry_unused);
>> - sb->s_nr_dentry_unused = 0;
>> -
>> - spin_unlock(&sb->s_dentry_lru_lock);
>> - shrink_dcache_list(&tmp);
>> - spin_lock(&sb->s_dentry_lru_lock);
>> - }
>> - spin_unlock(&sb->s_dentry_lru_lock);
>> + list_lru_dispose_all(&sb->s_dentry_lru, shrink_dcache_list);
>> }
>> EXPORT_SYMBOL(shrink_dcache_sb);
>
> And here comes the fun part. This doesn't account for the
> dentries that are freed from the superblock here.
>
> So, it needs to be something like:
>
> void shrink_dcache_sb(struct super_block *sb)
> {
> unsigned long disposed;
>
> disposed = list_lru_dispose_all(&sb->s_dentry_lru,
> shrink_dcache_list);
>
> this_cpu_sub(nr_dentry_unused, disposed);
> }
>
> But, therein lies a problem. nr_dentry_unused is a 32 bit counter,
> and we can return a 64 bit value here. So that means we have to bump
> nr_dentry_unused to a long, not an int for these per-cpu counters to
> work.
>
> And then there's the problem that the sum of these counters only
> uses an int. Which means if we get large numbers of negative values
> on different CPU from unmounts, the summation will end up
> overflowing and it'll all suck.
>
> So, Glauber, what do you reckon? I've never likes this stupid
> hand-rolled per-cpu counter stuff, and it's causing issues. Should
> we just convert them to generic per-cpu counters because they are
> 64bit clean and just handle out-of-range sums in the /proc update
> code?
>
One option would be to add the following patch to the beginning of the
series.
[-- Attachment #2: dentry.patch --]
[-- Type: text/x-patch, Size: 2952 bytes --]
diff --git a/fs/dcache.c b/fs/dcache.c
index 3a3adc4..a8be4c9 100644
--- a/fs/dcache.c
+++ b/fs/dcache.c
@@ -116,12 +116,12 @@ struct dentry_stat_t dentry_stat = {
.age_limit = 45,
};
-static DEFINE_PER_CPU(unsigned int, nr_dentry);
-static DEFINE_PER_CPU(unsigned int, nr_dentry_unused);
+static DEFINE_PER_CPU(long, nr_dentry);
+static DEFINE_PER_CPU(long, nr_dentry_unused);
#if defined(CONFIG_SYSCTL) && defined(CONFIG_PROC_FS)
/* scan possible cpus instead of online and avoid worrying about CPU hotplug. */
-static int get_nr_dentry(void)
+static long get_nr_dentry(void)
{
int i;
int sum = 0;
@@ -130,7 +130,7 @@ static int get_nr_dentry(void)
return sum < 0 ? 0 : sum;
}
-static int get_nr_dentry_unused(void)
+static long get_nr_dentry_unused(void)
{
int i;
int sum = 0;
@@ -144,7 +144,7 @@ int proc_nr_dentry(ctl_table *table, int write, void __user *buffer,
{
dentry_stat.nr_dentry = get_nr_dentry();
dentry_stat.nr_unused = get_nr_dentry_unused();
- return proc_dointvec(table, write, buffer, lenp, ppos);
+ return proc_doulongvec_minmax(table, write, buffer, lenp, ppos);
}
#endif
diff --git a/include/linux/dcache.h b/include/linux/dcache.h
index 4d24a12..bd08285 100644
--- a/include/linux/dcache.h
+++ b/include/linux/dcache.h
@@ -54,11 +54,11 @@ struct qstr {
#define hashlen_len(hashlen) ((u32)((hashlen) >> 32))
struct dentry_stat_t {
- int nr_dentry;
- int nr_unused;
- int age_limit; /* age in seconds */
- int want_pages; /* pages requested by system */
- int dummy[2];
+ long nr_dentry;
+ long nr_unused;
+ long age_limit; /* age in seconds */
+ long want_pages; /* pages requested by system */
+ long dummy[2];
};
extern struct dentry_stat_t dentry_stat;
diff --git a/include/linux/fs.h b/include/linux/fs.h
index 67e1040..e875f60 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -1267,12 +1267,12 @@ struct super_block {
/* s_dentry_lru_lock protects s_dentry_lru and s_nr_dentry_unused */
spinlock_t s_dentry_lru_lock ____cacheline_aligned_in_smp;
struct list_head s_dentry_lru; /* unused dentry lru */
- int s_nr_dentry_unused; /* # of dentry on lru */
+ long s_nr_dentry_unused; /* # of dentry on lru */
/* s_inode_lru_lock protects s_inode_lru and s_nr_inodes_unused */
spinlock_t s_inode_lru_lock ____cacheline_aligned_in_smp;
struct list_head s_inode_lru; /* unused inode lru */
- int s_nr_inodes_unused; /* # of inodes on lru */
+ long s_nr_inodes_unused; /* # of inodes on lru */
struct block_device *s_bdev;
struct backing_dev_info *s_bdi;
diff --git a/kernel/sysctl.c b/kernel/sysctl.c
index 9edcf45..0dc51c0 100644
--- a/kernel/sysctl.c
+++ b/kernel/sysctl.c
@@ -1493,7 +1493,7 @@ static struct ctl_table fs_table[] = {
{
.procname = "dentry-state",
.data = &dentry_stat,
- .maxlen = 6*sizeof(int),
+ .maxlen = 6*sizeof(long),
.mode = 0444,
.proc_handler = proc_nr_dentry,
},
^ permalink raw reply related [flat|nested] 151+ messages in thread* Re: [PATCH v6 09/31] dcache: convert to use new lru list infrastructure
@ 2013-05-14 14:01 ` Glauber Costa
0 siblings, 0 replies; 151+ messages in thread
From: Glauber Costa @ 2013-05-14 14:01 UTC (permalink / raw)
To: Dave Chinner
Cc: Glauber Costa, linux-mm-Bw31MaZKKs3YtjvyW6yDsg,
cgroups-u79uwXL29TY76Z2rM5mHXA, Andrew Morton, Greg Thelen,
kamezawa.hiroyu-+CUm20s59erQFUHtdCDX3A, Michal Hocko,
Johannes Weiner, linux-fsdevel-u79uwXL29TY76Z2rM5mHXA,
Dave Chinner
[-- Attachment #1: Type: text/plain, Size: 2662 bytes --]
On 05/14/2013 10:59 AM, Dave Chinner wrote:
> On Sun, May 12, 2013 at 10:13:30PM +0400, Glauber Costa wrote:
>> From: Dave Chinner <dchinner-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>
>>
>> [ glommer: don't reintroduce double decrement of nr_unused_dentries,
>> adapted for new LRU return codes ]
>> Signed-off-by: Dave Chinner <dchinner-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>
>> Signed-off-by: Glauber Costa <glommer-GEFAQzZX7r8dnm+yROfE0A@public.gmane.org>
>> ---
>
> I'm seeing a panic on startup in d_kill() with an invalid d_child
> list entry with this patch. I haven't got to the bottom of it yet.
>
My wild guess is that your patch does not prune correctly, as I
described in my last message.
> .....
>
>> void shrink_dcache_sb(struct super_block *sb)
>> {
>> - LIST_HEAD(tmp);
>> -
>> - spin_lock(&sb->s_dentry_lru_lock);
>> - while (!list_empty(&sb->s_dentry_lru)) {
>> - list_splice_init(&sb->s_dentry_lru, &tmp);
>> -
>> - /*
>> - * account for removal here so we don't need to handle it later
>> - * even though the dentry is no longer on the lru list.
>> - */
>> - this_cpu_sub(nr_dentry_unused, sb->s_nr_dentry_unused);
>> - sb->s_nr_dentry_unused = 0;
>> -
>> - spin_unlock(&sb->s_dentry_lru_lock);
>> - shrink_dcache_list(&tmp);
>> - spin_lock(&sb->s_dentry_lru_lock);
>> - }
>> - spin_unlock(&sb->s_dentry_lru_lock);
>> + list_lru_dispose_all(&sb->s_dentry_lru, shrink_dcache_list);
>> }
>> EXPORT_SYMBOL(shrink_dcache_sb);
>
> And here comes the fun part. This doesn't account for the
> dentries that are freed from the superblock here.
>
> So, it needs to be something like:
>
> void shrink_dcache_sb(struct super_block *sb)
> {
> unsigned long disposed;
>
> disposed = list_lru_dispose_all(&sb->s_dentry_lru,
> shrink_dcache_list);
>
> this_cpu_sub(nr_dentry_unused, disposed);
> }
>
> But, therein lies a problem. nr_dentry_unused is a 32 bit counter,
> and we can return a 64 bit value here. So that means we have to bump
> nr_dentry_unused to a long, not an int for these per-cpu counters to
> work.
>
> And then there's the problem that the sum of these counters only
> uses an int. Which means if we get large numbers of negative values
> on different CPU from unmounts, the summation will end up
> overflowing and it'll all suck.
>
> So, Glauber, what do you reckon? I've never likes this stupid
> hand-rolled per-cpu counter stuff, and it's causing issues. Should
> we just convert them to generic per-cpu counters because they are
> 64bit clean and just handle out-of-range sums in the /proc update
> code?
>
One option would be to add the following patch to the beginning of the
series.
[-- Attachment #2: dentry.patch --]
[-- Type: text/x-patch, Size: 2952 bytes --]
diff --git a/fs/dcache.c b/fs/dcache.c
index 3a3adc4..a8be4c9 100644
--- a/fs/dcache.c
+++ b/fs/dcache.c
@@ -116,12 +116,12 @@ struct dentry_stat_t dentry_stat = {
.age_limit = 45,
};
-static DEFINE_PER_CPU(unsigned int, nr_dentry);
-static DEFINE_PER_CPU(unsigned int, nr_dentry_unused);
+static DEFINE_PER_CPU(long, nr_dentry);
+static DEFINE_PER_CPU(long, nr_dentry_unused);
#if defined(CONFIG_SYSCTL) && defined(CONFIG_PROC_FS)
/* scan possible cpus instead of online and avoid worrying about CPU hotplug. */
-static int get_nr_dentry(void)
+static long get_nr_dentry(void)
{
int i;
int sum = 0;
@@ -130,7 +130,7 @@ static int get_nr_dentry(void)
return sum < 0 ? 0 : sum;
}
-static int get_nr_dentry_unused(void)
+static long get_nr_dentry_unused(void)
{
int i;
int sum = 0;
@@ -144,7 +144,7 @@ int proc_nr_dentry(ctl_table *table, int write, void __user *buffer,
{
dentry_stat.nr_dentry = get_nr_dentry();
dentry_stat.nr_unused = get_nr_dentry_unused();
- return proc_dointvec(table, write, buffer, lenp, ppos);
+ return proc_doulongvec_minmax(table, write, buffer, lenp, ppos);
}
#endif
diff --git a/include/linux/dcache.h b/include/linux/dcache.h
index 4d24a12..bd08285 100644
--- a/include/linux/dcache.h
+++ b/include/linux/dcache.h
@@ -54,11 +54,11 @@ struct qstr {
#define hashlen_len(hashlen) ((u32)((hashlen) >> 32))
struct dentry_stat_t {
- int nr_dentry;
- int nr_unused;
- int age_limit; /* age in seconds */
- int want_pages; /* pages requested by system */
- int dummy[2];
+ long nr_dentry;
+ long nr_unused;
+ long age_limit; /* age in seconds */
+ long want_pages; /* pages requested by system */
+ long dummy[2];
};
extern struct dentry_stat_t dentry_stat;
diff --git a/include/linux/fs.h b/include/linux/fs.h
index 67e1040..e875f60 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -1267,12 +1267,12 @@ struct super_block {
/* s_dentry_lru_lock protects s_dentry_lru and s_nr_dentry_unused */
spinlock_t s_dentry_lru_lock ____cacheline_aligned_in_smp;
struct list_head s_dentry_lru; /* unused dentry lru */
- int s_nr_dentry_unused; /* # of dentry on lru */
+ long s_nr_dentry_unused; /* # of dentry on lru */
/* s_inode_lru_lock protects s_inode_lru and s_nr_inodes_unused */
spinlock_t s_inode_lru_lock ____cacheline_aligned_in_smp;
struct list_head s_inode_lru; /* unused inode lru */
- int s_nr_inodes_unused; /* # of inodes on lru */
+ long s_nr_inodes_unused; /* # of inodes on lru */
struct block_device *s_bdev;
struct backing_dev_info *s_bdi;
diff --git a/kernel/sysctl.c b/kernel/sysctl.c
index 9edcf45..0dc51c0 100644
--- a/kernel/sysctl.c
+++ b/kernel/sysctl.c
@@ -1493,7 +1493,7 @@ static struct ctl_table fs_table[] = {
{
.procname = "dentry-state",
.data = &dentry_stat,
- .maxlen = 6*sizeof(int),
+ .maxlen = 6*sizeof(long),
.mode = 0444,
.proc_handler = proc_nr_dentry,
},
^ permalink raw reply related [flat|nested] 151+ messages in thread* Re: [PATCH v6 09/31] dcache: convert to use new lru list infrastructure
@ 2013-05-14 14:01 ` Glauber Costa
0 siblings, 0 replies; 151+ messages in thread
From: Glauber Costa @ 2013-05-14 14:01 UTC (permalink / raw)
To: Dave Chinner
Cc: Glauber Costa, linux-mm, cgroups, Andrew Morton, Greg Thelen,
kamezawa.hiroyu, Michal Hocko, Johannes Weiner, linux-fsdevel,
Dave Chinner
[-- Attachment #1: Type: text/plain, Size: 2575 bytes --]
On 05/14/2013 10:59 AM, Dave Chinner wrote:
> On Sun, May 12, 2013 at 10:13:30PM +0400, Glauber Costa wrote:
>> From: Dave Chinner <dchinner@redhat.com>
>>
>> [ glommer: don't reintroduce double decrement of nr_unused_dentries,
>> adapted for new LRU return codes ]
>> Signed-off-by: Dave Chinner <dchinner@redhat.com>
>> Signed-off-by: Glauber Costa <glommer@openvz.org>
>> ---
>
> I'm seeing a panic on startup in d_kill() with an invalid d_child
> list entry with this patch. I haven't got to the bottom of it yet.
>
My wild guess is that your patch does not prune correctly, as I
described in my last message.
> .....
>
>> void shrink_dcache_sb(struct super_block *sb)
>> {
>> - LIST_HEAD(tmp);
>> -
>> - spin_lock(&sb->s_dentry_lru_lock);
>> - while (!list_empty(&sb->s_dentry_lru)) {
>> - list_splice_init(&sb->s_dentry_lru, &tmp);
>> -
>> - /*
>> - * account for removal here so we don't need to handle it later
>> - * even though the dentry is no longer on the lru list.
>> - */
>> - this_cpu_sub(nr_dentry_unused, sb->s_nr_dentry_unused);
>> - sb->s_nr_dentry_unused = 0;
>> -
>> - spin_unlock(&sb->s_dentry_lru_lock);
>> - shrink_dcache_list(&tmp);
>> - spin_lock(&sb->s_dentry_lru_lock);
>> - }
>> - spin_unlock(&sb->s_dentry_lru_lock);
>> + list_lru_dispose_all(&sb->s_dentry_lru, shrink_dcache_list);
>> }
>> EXPORT_SYMBOL(shrink_dcache_sb);
>
> And here comes the fun part. This doesn't account for the
> dentries that are freed from the superblock here.
>
> So, it needs to be something like:
>
> void shrink_dcache_sb(struct super_block *sb)
> {
> unsigned long disposed;
>
> disposed = list_lru_dispose_all(&sb->s_dentry_lru,
> shrink_dcache_list);
>
> this_cpu_sub(nr_dentry_unused, disposed);
> }
>
> But, therein lies a problem. nr_dentry_unused is a 32 bit counter,
> and we can return a 64 bit value here. So that means we have to bump
> nr_dentry_unused to a long, not an int for these per-cpu counters to
> work.
>
> And then there's the problem that the sum of these counters only
> uses an int. Which means if we get large numbers of negative values
> on different CPU from unmounts, the summation will end up
> overflowing and it'll all suck.
>
> So, Glauber, what do you reckon? I've never likes this stupid
> hand-rolled per-cpu counter stuff, and it's causing issues. Should
> we just convert them to generic per-cpu counters because they are
> 64bit clean and just handle out-of-range sums in the /proc update
> code?
>
One option would be to add the following patch to the beginning of the
series.
[-- Attachment #2: dentry.patch --]
[-- Type: text/x-patch, Size: 2952 bytes --]
diff --git a/fs/dcache.c b/fs/dcache.c
index 3a3adc4..a8be4c9 100644
--- a/fs/dcache.c
+++ b/fs/dcache.c
@@ -116,12 +116,12 @@ struct dentry_stat_t dentry_stat = {
.age_limit = 45,
};
-static DEFINE_PER_CPU(unsigned int, nr_dentry);
-static DEFINE_PER_CPU(unsigned int, nr_dentry_unused);
+static DEFINE_PER_CPU(long, nr_dentry);
+static DEFINE_PER_CPU(long, nr_dentry_unused);
#if defined(CONFIG_SYSCTL) && defined(CONFIG_PROC_FS)
/* scan possible cpus instead of online and avoid worrying about CPU hotplug. */
-static int get_nr_dentry(void)
+static long get_nr_dentry(void)
{
int i;
int sum = 0;
@@ -130,7 +130,7 @@ static int get_nr_dentry(void)
return sum < 0 ? 0 : sum;
}
-static int get_nr_dentry_unused(void)
+static long get_nr_dentry_unused(void)
{
int i;
int sum = 0;
@@ -144,7 +144,7 @@ int proc_nr_dentry(ctl_table *table, int write, void __user *buffer,
{
dentry_stat.nr_dentry = get_nr_dentry();
dentry_stat.nr_unused = get_nr_dentry_unused();
- return proc_dointvec(table, write, buffer, lenp, ppos);
+ return proc_doulongvec_minmax(table, write, buffer, lenp, ppos);
}
#endif
diff --git a/include/linux/dcache.h b/include/linux/dcache.h
index 4d24a12..bd08285 100644
--- a/include/linux/dcache.h
+++ b/include/linux/dcache.h
@@ -54,11 +54,11 @@ struct qstr {
#define hashlen_len(hashlen) ((u32)((hashlen) >> 32))
struct dentry_stat_t {
- int nr_dentry;
- int nr_unused;
- int age_limit; /* age in seconds */
- int want_pages; /* pages requested by system */
- int dummy[2];
+ long nr_dentry;
+ long nr_unused;
+ long age_limit; /* age in seconds */
+ long want_pages; /* pages requested by system */
+ long dummy[2];
};
extern struct dentry_stat_t dentry_stat;
diff --git a/include/linux/fs.h b/include/linux/fs.h
index 67e1040..e875f60 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -1267,12 +1267,12 @@ struct super_block {
/* s_dentry_lru_lock protects s_dentry_lru and s_nr_dentry_unused */
spinlock_t s_dentry_lru_lock ____cacheline_aligned_in_smp;
struct list_head s_dentry_lru; /* unused dentry lru */
- int s_nr_dentry_unused; /* # of dentry on lru */
+ long s_nr_dentry_unused; /* # of dentry on lru */
/* s_inode_lru_lock protects s_inode_lru and s_nr_inodes_unused */
spinlock_t s_inode_lru_lock ____cacheline_aligned_in_smp;
struct list_head s_inode_lru; /* unused inode lru */
- int s_nr_inodes_unused; /* # of inodes on lru */
+ long s_nr_inodes_unused; /* # of inodes on lru */
struct block_device *s_bdev;
struct backing_dev_info *s_bdi;
diff --git a/kernel/sysctl.c b/kernel/sysctl.c
index 9edcf45..0dc51c0 100644
--- a/kernel/sysctl.c
+++ b/kernel/sysctl.c
@@ -1493,7 +1493,7 @@ static struct ctl_table fs_table[] = {
{
.procname = "dentry-state",
.data = &dentry_stat,
- .maxlen = 6*sizeof(int),
+ .maxlen = 6*sizeof(long),
.mode = 0444,
.proc_handler = proc_nr_dentry,
},
^ permalink raw reply related [flat|nested] 151+ messages in thread
* [PATCH v6 10/31] list_lru: per-node list infrastructure
2013-05-12 18:13 ` Glauber Costa
(?)
@ 2013-05-12 18:13 ` Glauber Costa
-1 siblings, 0 replies; 151+ messages in thread
From: Glauber Costa @ 2013-05-12 18:13 UTC (permalink / raw)
To: linux-mm
Cc: cgroups, Andrew Morton, Greg Thelen, kamezawa.hiroyu,
Michal Hocko, Johannes Weiner, linux-fsdevel, Dave Chinner,
Dave Chinner, Glauber Costa
From: Dave Chinner <dchinner@redhat.com>
Now that we have an LRU list API, we can start to enhance the
implementation. This splits the single LRU list into per-node lists
and locks to enhance scalability. Items are placed on lists
according to the node the memory belongs to. To make scanning the
lists efficient, also track whether the per-node lists have entries
in them in a active nodemask.
Note:
We use a fixed-size array for the node LRU, this struct can be very big
if MAX_NUMNODES is big. If this becomes a problem this is fixable by
turning this into a pointer and dynamically allocating this to
nr_node_ids. This quantity is firwmare-provided, and still would provide
room for all nodes at the cost of a pointer lookup and an extra
allocation. Because that allocation will most likely come from a
different slab cache than the main structure holding this structure, we
may very well fail.
[ glommer: fixed warnings, added note about node lru ]
Signed-off-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Glauber Costa <glommer@openvz.org>
Reviewed-by: Greg Thelen <gthelen@google.com>
Acked-by: Mel Gorman <mgorman@suse.de>
---
include/linux/list_lru.h | 24 +++++--
lib/list_lru.c | 161 +++++++++++++++++++++++++++++++++++------------
2 files changed, 139 insertions(+), 46 deletions(-)
diff --git a/include/linux/list_lru.h b/include/linux/list_lru.h
index 4f82a57..668f1f1 100644
--- a/include/linux/list_lru.h
+++ b/include/linux/list_lru.h
@@ -8,6 +8,7 @@
#define _LRU_LIST_H
#include <linux/list.h>
+#include <linux/nodemask.h>
enum lru_status {
LRU_REMOVED, /* item removed from list */
@@ -17,20 +18,31 @@ enum lru_status {
internally, but has to return locked. */
};
-struct list_lru {
+struct list_lru_node {
spinlock_t lock;
struct list_head list;
long nr_items;
+} ____cacheline_aligned_in_smp;
+
+struct list_lru {
+ /*
+ * Because we use a fixed-size array, this struct can be very big if
+ * MAX_NUMNODES is big. If this becomes a problem this is fixable by
+ * turning this into a pointer and dynamically allocating this to
+ * nr_node_ids. This quantity is firwmare-provided, and still would
+ * provide room for all nodes at the cost of a pointer lookup and an
+ * extra allocation. Because that allocation will most likely come from
+ * a different slab cache than the main structure holding this
+ * structure, we may very well fail.
+ */
+ struct list_lru_node node[MAX_NUMNODES];
+ nodemask_t active_nodes;
};
int list_lru_init(struct list_lru *lru);
int list_lru_add(struct list_lru *lru, struct list_head *item);
int list_lru_del(struct list_lru *lru, struct list_head *item);
-
-static inline unsigned long list_lru_count(struct list_lru *lru)
-{
- return lru->nr_items;
-}
+unsigned long list_lru_count(struct list_lru *lru);
typedef enum lru_status
(*list_lru_walk_cb)(struct list_head *item, spinlock_t *lock, void *cb_arg);
diff --git a/lib/list_lru.c b/lib/list_lru.c
index 055db4b..6d43079 100644
--- a/lib/list_lru.c
+++ b/lib/list_lru.c
@@ -6,6 +6,7 @@
*/
#include <linux/kernel.h>
#include <linux/module.h>
+#include <linux/mm.h>
#include <linux/list_lru.h>
int
@@ -13,14 +14,19 @@ list_lru_add(
struct list_lru *lru,
struct list_head *item)
{
- spin_lock(&lru->lock);
+ int nid = page_to_nid(virt_to_page(item));
+ struct list_lru_node *nlru = &lru->node[nid];
+
+ spin_lock(&nlru->lock);
+ BUG_ON(nlru->nr_items < 0);
if (list_empty(item)) {
- list_add_tail(item, &lru->list);
- lru->nr_items++;
- spin_unlock(&lru->lock);
+ list_add_tail(item, &nlru->list);
+ if (nlru->nr_items++ == 0)
+ node_set(nid, lru->active_nodes);
+ spin_unlock(&nlru->lock);
return 1;
}
- spin_unlock(&lru->lock);
+ spin_unlock(&nlru->lock);
return 0;
}
EXPORT_SYMBOL_GPL(list_lru_add);
@@ -30,41 +36,69 @@ list_lru_del(
struct list_lru *lru,
struct list_head *item)
{
- spin_lock(&lru->lock);
+ int nid = page_to_nid(virt_to_page(item));
+ struct list_lru_node *nlru = &lru->node[nid];
+
+ spin_lock(&nlru->lock);
if (!list_empty(item)) {
list_del_init(item);
- lru->nr_items--;
- spin_unlock(&lru->lock);
+ if (--nlru->nr_items == 0)
+ node_clear(nid, lru->active_nodes);
+ BUG_ON(nlru->nr_items < 0);
+ spin_unlock(&nlru->lock);
return 1;
}
- spin_unlock(&lru->lock);
+ spin_unlock(&nlru->lock);
return 0;
}
EXPORT_SYMBOL_GPL(list_lru_del);
unsigned long
-list_lru_walk(
- struct list_lru *lru,
- list_lru_walk_cb isolate,
- void *cb_arg,
- unsigned long nr_to_walk)
+list_lru_count(struct list_lru *lru)
{
+ long count = 0;
+ int nid;
+
+ for_each_node_mask(nid, lru->active_nodes) {
+ struct list_lru_node *nlru = &lru->node[nid];
+
+ spin_lock(&nlru->lock);
+ BUG_ON(nlru->nr_items < 0);
+ count += nlru->nr_items;
+ spin_unlock(&nlru->lock);
+ }
+
+ return count;
+}
+EXPORT_SYMBOL_GPL(list_lru_count);
+
+static unsigned long
+list_lru_walk_node(
+ struct list_lru *lru,
+ int nid,
+ list_lru_walk_cb isolate,
+ void *cb_arg,
+ unsigned long *nr_to_walk)
+{
+ struct list_lru_node *nlru = &lru->node[nid];
struct list_head *item, *n;
- unsigned long removed = 0;
+ unsigned long isolated = 0;
- spin_lock(&lru->lock);
- list_for_each_safe(item, n, &lru->list) {
+ spin_lock(&nlru->lock);
+ list_for_each_safe(item, n, &nlru->list) {
enum lru_status ret;
bool first_pass = true;
restart:
- ret = isolate(item, &lru->lock, cb_arg);
+ ret = isolate(item, &nlru->lock, cb_arg);
switch (ret) {
case LRU_REMOVED:
- lru->nr_items--;
- removed++;
+ if (--nlru->nr_items == 0)
+ node_clear(nid, lru->active_nodes);
+ BUG_ON(nlru->nr_items < 0);
+ isolated++;
break;
case LRU_ROTATE:
- list_move_tail(item, &lru->list);
+ list_move_tail(item, &nlru->list);
break;
case LRU_SKIP:
break;
@@ -76,46 +110,93 @@ restart:
BUG();
}
- if (nr_to_walk-- == 0)
+ if ((*nr_to_walk)-- == 0)
break;
}
- spin_unlock(&lru->lock);
- return removed;
+ spin_unlock(&nlru->lock);
+ return isolated;
}
-EXPORT_SYMBOL_GPL(list_lru_walk);
unsigned long
-list_lru_dispose_all(
- struct list_lru *lru,
- list_lru_dispose_cb dispose)
+list_lru_walk(
+ struct list_lru *lru,
+ list_lru_walk_cb isolate,
+ void *cb_arg,
+ unsigned long nr_to_walk)
{
- unsigned long disposed = 0;
+ long isolated = 0;
+ int nid;
+
+ for_each_node_mask(nid, lru->active_nodes) {
+ isolated += list_lru_walk_node(lru, nid, isolate,
+ cb_arg, &nr_to_walk);
+ if (nr_to_walk <= 0)
+ break;
+ }
+ return isolated;
+}
+EXPORT_SYMBOL_GPL(list_lru_walk);
+
+static unsigned long
+list_lru_dispose_all_node(
+ struct list_lru *lru,
+ int nid,
+ list_lru_dispose_cb dispose)
+{
+ struct list_lru_node *nlru = &lru->node[nid];
LIST_HEAD(dispose_list);
+ unsigned long disposed = 0;
- spin_lock(&lru->lock);
- while (!list_empty(&lru->list)) {
- list_splice_init(&lru->list, &dispose_list);
- disposed += lru->nr_items;
- lru->nr_items = 0;
- spin_unlock(&lru->lock);
+ spin_lock(&nlru->lock);
+ while (!list_empty(&nlru->list)) {
+ list_splice_init(&nlru->list, &dispose_list);
+ disposed += nlru->nr_items;
+ nlru->nr_items = 0;
+ node_clear(nid, lru->active_nodes);
+ spin_unlock(&nlru->lock);
dispose(&dispose_list);
- spin_lock(&lru->lock);
+ spin_lock(&nlru->lock);
}
- spin_unlock(&lru->lock);
+ spin_unlock(&nlru->lock);
return disposed;
}
+unsigned long
+list_lru_dispose_all(
+ struct list_lru *lru,
+ list_lru_dispose_cb dispose)
+{
+ unsigned long disposed;
+ unsigned long total = 0;
+ int nid;
+
+ do {
+ disposed = 0;
+ for_each_node_mask(nid, lru->active_nodes) {
+ disposed += list_lru_dispose_all_node(lru, nid,
+ dispose);
+ }
+ total += disposed;
+ } while (disposed != 0);
+
+ return total;
+}
+
int
list_lru_init(
struct list_lru *lru)
{
- spin_lock_init(&lru->lock);
- INIT_LIST_HEAD(&lru->list);
- lru->nr_items = 0;
+ int i;
+ nodes_clear(lru->active_nodes);
+ for (i = 0; i < MAX_NUMNODES; i++) {
+ spin_lock_init(&lru->node[i].lock);
+ INIT_LIST_HEAD(&lru->node[i].list);
+ lru->node[i].nr_items = 0;
+ }
return 0;
}
EXPORT_SYMBOL_GPL(list_lru_init);
--
1.8.1.4
^ permalink raw reply related [flat|nested] 151+ messages in thread* [PATCH v6 10/31] list_lru: per-node list infrastructure
@ 2013-05-12 18:13 ` Glauber Costa
0 siblings, 0 replies; 151+ messages in thread
From: Glauber Costa @ 2013-05-12 18:13 UTC (permalink / raw)
To: linux-mm
Cc: cgroups, Andrew Morton, Greg Thelen, kamezawa.hiroyu,
Michal Hocko, Johannes Weiner, linux-fsdevel, Dave Chinner,
Dave Chinner, Glauber Costa
From: Dave Chinner <dchinner@redhat.com>
Now that we have an LRU list API, we can start to enhance the
implementation. This splits the single LRU list into per-node lists
and locks to enhance scalability. Items are placed on lists
according to the node the memory belongs to. To make scanning the
lists efficient, also track whether the per-node lists have entries
in them in a active nodemask.
Note:
We use a fixed-size array for the node LRU, this struct can be very big
if MAX_NUMNODES is big. If this becomes a problem this is fixable by
turning this into a pointer and dynamically allocating this to
nr_node_ids. This quantity is firwmare-provided, and still would provide
room for all nodes at the cost of a pointer lookup and an extra
allocation. Because that allocation will most likely come from a
different slab cache than the main structure holding this structure, we
may very well fail.
[ glommer: fixed warnings, added note about node lru ]
Signed-off-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Glauber Costa <glommer@openvz.org>
Reviewed-by: Greg Thelen <gthelen@google.com>
Acked-by: Mel Gorman <mgorman@suse.de>
---
include/linux/list_lru.h | 24 +++++--
lib/list_lru.c | 161 +++++++++++++++++++++++++++++++++++------------
2 files changed, 139 insertions(+), 46 deletions(-)
diff --git a/include/linux/list_lru.h b/include/linux/list_lru.h
index 4f82a57..668f1f1 100644
--- a/include/linux/list_lru.h
+++ b/include/linux/list_lru.h
@@ -8,6 +8,7 @@
#define _LRU_LIST_H
#include <linux/list.h>
+#include <linux/nodemask.h>
enum lru_status {
LRU_REMOVED, /* item removed from list */
@@ -17,20 +18,31 @@ enum lru_status {
internally, but has to return locked. */
};
-struct list_lru {
+struct list_lru_node {
spinlock_t lock;
struct list_head list;
long nr_items;
+} ____cacheline_aligned_in_smp;
+
+struct list_lru {
+ /*
+ * Because we use a fixed-size array, this struct can be very big if
+ * MAX_NUMNODES is big. If this becomes a problem this is fixable by
+ * turning this into a pointer and dynamically allocating this to
+ * nr_node_ids. This quantity is firwmare-provided, and still would
+ * provide room for all nodes at the cost of a pointer lookup and an
+ * extra allocation. Because that allocation will most likely come from
+ * a different slab cache than the main structure holding this
+ * structure, we may very well fail.
+ */
+ struct list_lru_node node[MAX_NUMNODES];
+ nodemask_t active_nodes;
};
int list_lru_init(struct list_lru *lru);
int list_lru_add(struct list_lru *lru, struct list_head *item);
int list_lru_del(struct list_lru *lru, struct list_head *item);
-
-static inline unsigned long list_lru_count(struct list_lru *lru)
-{
- return lru->nr_items;
-}
+unsigned long list_lru_count(struct list_lru *lru);
typedef enum lru_status
(*list_lru_walk_cb)(struct list_head *item, spinlock_t *lock, void *cb_arg);
diff --git a/lib/list_lru.c b/lib/list_lru.c
index 055db4b..6d43079 100644
--- a/lib/list_lru.c
+++ b/lib/list_lru.c
@@ -6,6 +6,7 @@
*/
#include <linux/kernel.h>
#include <linux/module.h>
+#include <linux/mm.h>
#include <linux/list_lru.h>
int
@@ -13,14 +14,19 @@ list_lru_add(
struct list_lru *lru,
struct list_head *item)
{
- spin_lock(&lru->lock);
+ int nid = page_to_nid(virt_to_page(item));
+ struct list_lru_node *nlru = &lru->node[nid];
+
+ spin_lock(&nlru->lock);
+ BUG_ON(nlru->nr_items < 0);
if (list_empty(item)) {
- list_add_tail(item, &lru->list);
- lru->nr_items++;
- spin_unlock(&lru->lock);
+ list_add_tail(item, &nlru->list);
+ if (nlru->nr_items++ == 0)
+ node_set(nid, lru->active_nodes);
+ spin_unlock(&nlru->lock);
return 1;
}
- spin_unlock(&lru->lock);
+ spin_unlock(&nlru->lock);
return 0;
}
EXPORT_SYMBOL_GPL(list_lru_add);
@@ -30,41 +36,69 @@ list_lru_del(
struct list_lru *lru,
struct list_head *item)
{
- spin_lock(&lru->lock);
+ int nid = page_to_nid(virt_to_page(item));
+ struct list_lru_node *nlru = &lru->node[nid];
+
+ spin_lock(&nlru->lock);
if (!list_empty(item)) {
list_del_init(item);
- lru->nr_items--;
- spin_unlock(&lru->lock);
+ if (--nlru->nr_items == 0)
+ node_clear(nid, lru->active_nodes);
+ BUG_ON(nlru->nr_items < 0);
+ spin_unlock(&nlru->lock);
return 1;
}
- spin_unlock(&lru->lock);
+ spin_unlock(&nlru->lock);
return 0;
}
EXPORT_SYMBOL_GPL(list_lru_del);
unsigned long
-list_lru_walk(
- struct list_lru *lru,
- list_lru_walk_cb isolate,
- void *cb_arg,
- unsigned long nr_to_walk)
+list_lru_count(struct list_lru *lru)
{
+ long count = 0;
+ int nid;
+
+ for_each_node_mask(nid, lru->active_nodes) {
+ struct list_lru_node *nlru = &lru->node[nid];
+
+ spin_lock(&nlru->lock);
+ BUG_ON(nlru->nr_items < 0);
+ count += nlru->nr_items;
+ spin_unlock(&nlru->lock);
+ }
+
+ return count;
+}
+EXPORT_SYMBOL_GPL(list_lru_count);
+
+static unsigned long
+list_lru_walk_node(
+ struct list_lru *lru,
+ int nid,
+ list_lru_walk_cb isolate,
+ void *cb_arg,
+ unsigned long *nr_to_walk)
+{
+ struct list_lru_node *nlru = &lru->node[nid];
struct list_head *item, *n;
- unsigned long removed = 0;
+ unsigned long isolated = 0;
- spin_lock(&lru->lock);
- list_for_each_safe(item, n, &lru->list) {
+ spin_lock(&nlru->lock);
+ list_for_each_safe(item, n, &nlru->list) {
enum lru_status ret;
bool first_pass = true;
restart:
- ret = isolate(item, &lru->lock, cb_arg);
+ ret = isolate(item, &nlru->lock, cb_arg);
switch (ret) {
case LRU_REMOVED:
- lru->nr_items--;
- removed++;
+ if (--nlru->nr_items == 0)
+ node_clear(nid, lru->active_nodes);
+ BUG_ON(nlru->nr_items < 0);
+ isolated++;
break;
case LRU_ROTATE:
- list_move_tail(item, &lru->list);
+ list_move_tail(item, &nlru->list);
break;
case LRU_SKIP:
break;
@@ -76,46 +110,93 @@ restart:
BUG();
}
- if (nr_to_walk-- == 0)
+ if ((*nr_to_walk)-- == 0)
break;
}
- spin_unlock(&lru->lock);
- return removed;
+ spin_unlock(&nlru->lock);
+ return isolated;
}
-EXPORT_SYMBOL_GPL(list_lru_walk);
unsigned long
-list_lru_dispose_all(
- struct list_lru *lru,
- list_lru_dispose_cb dispose)
+list_lru_walk(
+ struct list_lru *lru,
+ list_lru_walk_cb isolate,
+ void *cb_arg,
+ unsigned long nr_to_walk)
{
- unsigned long disposed = 0;
+ long isolated = 0;
+ int nid;
+
+ for_each_node_mask(nid, lru->active_nodes) {
+ isolated += list_lru_walk_node(lru, nid, isolate,
+ cb_arg, &nr_to_walk);
+ if (nr_to_walk <= 0)
+ break;
+ }
+ return isolated;
+}
+EXPORT_SYMBOL_GPL(list_lru_walk);
+
+static unsigned long
+list_lru_dispose_all_node(
+ struct list_lru *lru,
+ int nid,
+ list_lru_dispose_cb dispose)
+{
+ struct list_lru_node *nlru = &lru->node[nid];
LIST_HEAD(dispose_list);
+ unsigned long disposed = 0;
- spin_lock(&lru->lock);
- while (!list_empty(&lru->list)) {
- list_splice_init(&lru->list, &dispose_list);
- disposed += lru->nr_items;
- lru->nr_items = 0;
- spin_unlock(&lru->lock);
+ spin_lock(&nlru->lock);
+ while (!list_empty(&nlru->list)) {
+ list_splice_init(&nlru->list, &dispose_list);
+ disposed += nlru->nr_items;
+ nlru->nr_items = 0;
+ node_clear(nid, lru->active_nodes);
+ spin_unlock(&nlru->lock);
dispose(&dispose_list);
- spin_lock(&lru->lock);
+ spin_lock(&nlru->lock);
}
- spin_unlock(&lru->lock);
+ spin_unlock(&nlru->lock);
return disposed;
}
+unsigned long
+list_lru_dispose_all(
+ struct list_lru *lru,
+ list_lru_dispose_cb dispose)
+{
+ unsigned long disposed;
+ unsigned long total = 0;
+ int nid;
+
+ do {
+ disposed = 0;
+ for_each_node_mask(nid, lru->active_nodes) {
+ disposed += list_lru_dispose_all_node(lru, nid,
+ dispose);
+ }
+ total += disposed;
+ } while (disposed != 0);
+
+ return total;
+}
+
int
list_lru_init(
struct list_lru *lru)
{
- spin_lock_init(&lru->lock);
- INIT_LIST_HEAD(&lru->list);
- lru->nr_items = 0;
+ int i;
+ nodes_clear(lru->active_nodes);
+ for (i = 0; i < MAX_NUMNODES; i++) {
+ spin_lock_init(&lru->node[i].lock);
+ INIT_LIST_HEAD(&lru->node[i].list);
+ lru->node[i].nr_items = 0;
+ }
return 0;
}
EXPORT_SYMBOL_GPL(list_lru_init);
--
1.8.1.4
^ permalink raw reply related [flat|nested] 151+ messages in thread* [PATCH v6 10/31] list_lru: per-node list infrastructure
@ 2013-05-12 18:13 ` Glauber Costa
0 siblings, 0 replies; 151+ messages in thread
From: Glauber Costa @ 2013-05-12 18:13 UTC (permalink / raw)
To: linux-mm
Cc: cgroups, Andrew Morton, Greg Thelen, kamezawa.hiroyu,
Michal Hocko, Johannes Weiner, linux-fsdevel, Dave Chinner,
Dave Chinner, Glauber Costa
From: Dave Chinner <dchinner@redhat.com>
Now that we have an LRU list API, we can start to enhance the
implementation. This splits the single LRU list into per-node lists
and locks to enhance scalability. Items are placed on lists
according to the node the memory belongs to. To make scanning the
lists efficient, also track whether the per-node lists have entries
in them in a active nodemask.
Note:
We use a fixed-size array for the node LRU, this struct can be very big
if MAX_NUMNODES is big. If this becomes a problem this is fixable by
turning this into a pointer and dynamically allocating this to
nr_node_ids. This quantity is firwmare-provided, and still would provide
room for all nodes at the cost of a pointer lookup and an extra
allocation. Because that allocation will most likely come from a
different slab cache than the main structure holding this structure, we
may very well fail.
[ glommer: fixed warnings, added note about node lru ]
Signed-off-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Glauber Costa <glommer@openvz.org>
Reviewed-by: Greg Thelen <gthelen@google.com>
Acked-by: Mel Gorman <mgorman@suse.de>
---
include/linux/list_lru.h | 24 +++++--
lib/list_lru.c | 161 +++++++++++++++++++++++++++++++++++------------
2 files changed, 139 insertions(+), 46 deletions(-)
diff --git a/include/linux/list_lru.h b/include/linux/list_lru.h
index 4f82a57..668f1f1 100644
--- a/include/linux/list_lru.h
+++ b/include/linux/list_lru.h
@@ -8,6 +8,7 @@
#define _LRU_LIST_H
#include <linux/list.h>
+#include <linux/nodemask.h>
enum lru_status {
LRU_REMOVED, /* item removed from list */
@@ -17,20 +18,31 @@ enum lru_status {
internally, but has to return locked. */
};
-struct list_lru {
+struct list_lru_node {
spinlock_t lock;
struct list_head list;
long nr_items;
+} ____cacheline_aligned_in_smp;
+
+struct list_lru {
+ /*
+ * Because we use a fixed-size array, this struct can be very big if
+ * MAX_NUMNODES is big. If this becomes a problem this is fixable by
+ * turning this into a pointer and dynamically allocating this to
+ * nr_node_ids. This quantity is firwmare-provided, and still would
+ * provide room for all nodes at the cost of a pointer lookup and an
+ * extra allocation. Because that allocation will most likely come from
+ * a different slab cache than the main structure holding this
+ * structure, we may very well fail.
+ */
+ struct list_lru_node node[MAX_NUMNODES];
+ nodemask_t active_nodes;
};
int list_lru_init(struct list_lru *lru);
int list_lru_add(struct list_lru *lru, struct list_head *item);
int list_lru_del(struct list_lru *lru, struct list_head *item);
-
-static inline unsigned long list_lru_count(struct list_lru *lru)
-{
- return lru->nr_items;
-}
+unsigned long list_lru_count(struct list_lru *lru);
typedef enum lru_status
(*list_lru_walk_cb)(struct list_head *item, spinlock_t *lock, void *cb_arg);
diff --git a/lib/list_lru.c b/lib/list_lru.c
index 055db4b..6d43079 100644
--- a/lib/list_lru.c
+++ b/lib/list_lru.c
@@ -6,6 +6,7 @@
*/
#include <linux/kernel.h>
#include <linux/module.h>
+#include <linux/mm.h>
#include <linux/list_lru.h>
int
@@ -13,14 +14,19 @@ list_lru_add(
struct list_lru *lru,
struct list_head *item)
{
- spin_lock(&lru->lock);
+ int nid = page_to_nid(virt_to_page(item));
+ struct list_lru_node *nlru = &lru->node[nid];
+
+ spin_lock(&nlru->lock);
+ BUG_ON(nlru->nr_items < 0);
if (list_empty(item)) {
- list_add_tail(item, &lru->list);
- lru->nr_items++;
- spin_unlock(&lru->lock);
+ list_add_tail(item, &nlru->list);
+ if (nlru->nr_items++ == 0)
+ node_set(nid, lru->active_nodes);
+ spin_unlock(&nlru->lock);
return 1;
}
- spin_unlock(&lru->lock);
+ spin_unlock(&nlru->lock);
return 0;
}
EXPORT_SYMBOL_GPL(list_lru_add);
@@ -30,41 +36,69 @@ list_lru_del(
struct list_lru *lru,
struct list_head *item)
{
- spin_lock(&lru->lock);
+ int nid = page_to_nid(virt_to_page(item));
+ struct list_lru_node *nlru = &lru->node[nid];
+
+ spin_lock(&nlru->lock);
if (!list_empty(item)) {
list_del_init(item);
- lru->nr_items--;
- spin_unlock(&lru->lock);
+ if (--nlru->nr_items == 0)
+ node_clear(nid, lru->active_nodes);
+ BUG_ON(nlru->nr_items < 0);
+ spin_unlock(&nlru->lock);
return 1;
}
- spin_unlock(&lru->lock);
+ spin_unlock(&nlru->lock);
return 0;
}
EXPORT_SYMBOL_GPL(list_lru_del);
unsigned long
-list_lru_walk(
- struct list_lru *lru,
- list_lru_walk_cb isolate,
- void *cb_arg,
- unsigned long nr_to_walk)
+list_lru_count(struct list_lru *lru)
{
+ long count = 0;
+ int nid;
+
+ for_each_node_mask(nid, lru->active_nodes) {
+ struct list_lru_node *nlru = &lru->node[nid];
+
+ spin_lock(&nlru->lock);
+ BUG_ON(nlru->nr_items < 0);
+ count += nlru->nr_items;
+ spin_unlock(&nlru->lock);
+ }
+
+ return count;
+}
+EXPORT_SYMBOL_GPL(list_lru_count);
+
+static unsigned long
+list_lru_walk_node(
+ struct list_lru *lru,
+ int nid,
+ list_lru_walk_cb isolate,
+ void *cb_arg,
+ unsigned long *nr_to_walk)
+{
+ struct list_lru_node *nlru = &lru->node[nid];
struct list_head *item, *n;
- unsigned long removed = 0;
+ unsigned long isolated = 0;
- spin_lock(&lru->lock);
- list_for_each_safe(item, n, &lru->list) {
+ spin_lock(&nlru->lock);
+ list_for_each_safe(item, n, &nlru->list) {
enum lru_status ret;
bool first_pass = true;
restart:
- ret = isolate(item, &lru->lock, cb_arg);
+ ret = isolate(item, &nlru->lock, cb_arg);
switch (ret) {
case LRU_REMOVED:
- lru->nr_items--;
- removed++;
+ if (--nlru->nr_items == 0)
+ node_clear(nid, lru->active_nodes);
+ BUG_ON(nlru->nr_items < 0);
+ isolated++;
break;
case LRU_ROTATE:
- list_move_tail(item, &lru->list);
+ list_move_tail(item, &nlru->list);
break;
case LRU_SKIP:
break;
@@ -76,46 +110,93 @@ restart:
BUG();
}
- if (nr_to_walk-- == 0)
+ if ((*nr_to_walk)-- == 0)
break;
}
- spin_unlock(&lru->lock);
- return removed;
+ spin_unlock(&nlru->lock);
+ return isolated;
}
-EXPORT_SYMBOL_GPL(list_lru_walk);
unsigned long
-list_lru_dispose_all(
- struct list_lru *lru,
- list_lru_dispose_cb dispose)
+list_lru_walk(
+ struct list_lru *lru,
+ list_lru_walk_cb isolate,
+ void *cb_arg,
+ unsigned long nr_to_walk)
{
- unsigned long disposed = 0;
+ long isolated = 0;
+ int nid;
+
+ for_each_node_mask(nid, lru->active_nodes) {
+ isolated += list_lru_walk_node(lru, nid, isolate,
+ cb_arg, &nr_to_walk);
+ if (nr_to_walk <= 0)
+ break;
+ }
+ return isolated;
+}
+EXPORT_SYMBOL_GPL(list_lru_walk);
+
+static unsigned long
+list_lru_dispose_all_node(
+ struct list_lru *lru,
+ int nid,
+ list_lru_dispose_cb dispose)
+{
+ struct list_lru_node *nlru = &lru->node[nid];
LIST_HEAD(dispose_list);
+ unsigned long disposed = 0;
- spin_lock(&lru->lock);
- while (!list_empty(&lru->list)) {
- list_splice_init(&lru->list, &dispose_list);
- disposed += lru->nr_items;
- lru->nr_items = 0;
- spin_unlock(&lru->lock);
+ spin_lock(&nlru->lock);
+ while (!list_empty(&nlru->list)) {
+ list_splice_init(&nlru->list, &dispose_list);
+ disposed += nlru->nr_items;
+ nlru->nr_items = 0;
+ node_clear(nid, lru->active_nodes);
+ spin_unlock(&nlru->lock);
dispose(&dispose_list);
- spin_lock(&lru->lock);
+ spin_lock(&nlru->lock);
}
- spin_unlock(&lru->lock);
+ spin_unlock(&nlru->lock);
return disposed;
}
+unsigned long
+list_lru_dispose_all(
+ struct list_lru *lru,
+ list_lru_dispose_cb dispose)
+{
+ unsigned long disposed;
+ unsigned long total = 0;
+ int nid;
+
+ do {
+ disposed = 0;
+ for_each_node_mask(nid, lru->active_nodes) {
+ disposed += list_lru_dispose_all_node(lru, nid,
+ dispose);
+ }
+ total += disposed;
+ } while (disposed != 0);
+
+ return total;
+}
+
int
list_lru_init(
struct list_lru *lru)
{
- spin_lock_init(&lru->lock);
- INIT_LIST_HEAD(&lru->list);
- lru->nr_items = 0;
+ int i;
+ nodes_clear(lru->active_nodes);
+ for (i = 0; i < MAX_NUMNODES; i++) {
+ spin_lock_init(&lru->node[i].lock);
+ INIT_LIST_HEAD(&lru->node[i].list);
+ lru->node[i].nr_items = 0;
+ }
return 0;
}
EXPORT_SYMBOL_GPL(list_lru_init);
--
1.8.1.4
--
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^ permalink raw reply related [flat|nested] 151+ messages in thread
* [PATCH v6 11/31] shrinker: add node awareness
2013-05-12 18:13 ` Glauber Costa
(?)
@ 2013-05-12 18:13 ` Glauber Costa
-1 siblings, 0 replies; 151+ messages in thread
From: Glauber Costa @ 2013-05-12 18:13 UTC (permalink / raw)
To: linux-mm
Cc: cgroups, Andrew Morton, Greg Thelen, kamezawa.hiroyu,
Michal Hocko, Johannes Weiner, linux-fsdevel, Dave Chinner,
Dave Chinner, Glauber Costa
From: Dave Chinner <dchinner@redhat.com>
Pass the node of the current zone being reclaimed to shrink_slab(),
allowing the shrinker control nodemask to be set appropriately for
node aware shrinkers.
[ v3: update ashmem ]
Signed-off-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Glauber Costa <glommer@openvz.org>
Acked-by: Mel Gorman <mgorman@suse.de>
---
drivers/staging/android/ashmem.c | 3 +++
fs/drop_caches.c | 1 +
include/linux/shrinker.h | 3 +++
mm/memory-failure.c | 2 ++
mm/vmscan.c | 12 +++++++++---
5 files changed, 18 insertions(+), 3 deletions(-)
diff --git a/drivers/staging/android/ashmem.c b/drivers/staging/android/ashmem.c
index e681bdd..3240d34 100644
--- a/drivers/staging/android/ashmem.c
+++ b/drivers/staging/android/ashmem.c
@@ -692,6 +692,9 @@ static long ashmem_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
.gfp_mask = GFP_KERNEL,
.nr_to_scan = 0,
};
+
+ nodes_setall(sc.nodes_to_scan);
+
ret = ashmem_shrink(&ashmem_shrinker, &sc);
sc.nr_to_scan = ret;
ashmem_shrink(&ashmem_shrinker, &sc);
diff --git a/fs/drop_caches.c b/fs/drop_caches.c
index f23d2a7..c3f44e7 100644
--- a/fs/drop_caches.c
+++ b/fs/drop_caches.c
@@ -44,6 +44,7 @@ static void drop_slab(void)
.gfp_mask = GFP_KERNEL,
};
+ nodes_setall(shrink.nodes_to_scan);
do {
nr_objects = shrink_slab(&shrink, 1000, 1000);
} while (nr_objects > 10);
diff --git a/include/linux/shrinker.h b/include/linux/shrinker.h
index c277b4e..98be3ab 100644
--- a/include/linux/shrinker.h
+++ b/include/linux/shrinker.h
@@ -16,6 +16,9 @@ struct shrink_control {
/* How many slab objects shrinker() should scan and try to reclaim */
long nr_to_scan;
+
+ /* shrink from these nodes */
+ nodemask_t nodes_to_scan;
};
/*
diff --git a/mm/memory-failure.c b/mm/memory-failure.c
index ceb0c7f..86788ff 100644
--- a/mm/memory-failure.c
+++ b/mm/memory-failure.c
@@ -248,10 +248,12 @@ void shake_page(struct page *p, int access)
*/
if (access) {
int nr;
+ int nid = page_to_nid(p);
do {
struct shrink_control shrink = {
.gfp_mask = GFP_KERNEL,
};
+ node_set(nid, shrink.nodes_to_scan);
nr = shrink_slab(&shrink, 1000, 1000);
if (page_count(p) == 1)
diff --git a/mm/vmscan.c b/mm/vmscan.c
index fd4639c..35a6a9b 100644
--- a/mm/vmscan.c
+++ b/mm/vmscan.c
@@ -2198,15 +2198,20 @@ static unsigned long do_try_to_free_pages(struct zonelist *zonelist,
*/
if (global_reclaim(sc)) {
unsigned long lru_pages = 0;
+
+ nodes_clear(shrink->nodes_to_scan);
for_each_zone_zonelist(zone, z, zonelist,
gfp_zone(sc->gfp_mask)) {
if (!cpuset_zone_allowed_hardwall(zone, GFP_KERNEL))
continue;
lru_pages += zone_reclaimable_pages(zone);
+ node_set(zone_to_nid(zone),
+ shrink->nodes_to_scan);
}
shrink_slab(shrink, sc->nr_scanned, lru_pages);
+
if (reclaim_state) {
sc->nr_reclaimed += reclaim_state->reclaimed_slab;
reclaim_state->reclaimed_slab = 0;
@@ -2782,6 +2787,8 @@ loop_again:
shrink_zone(zone, &sc);
reclaim_state->reclaimed_slab = 0;
+ nodes_clear(shrink.nodes_to_scan);
+ node_set(zone_to_nid(zone), shrink.nodes_to_scan);
nr_slab = shrink_slab(&shrink, sc.nr_scanned, lru_pages);
sc.nr_reclaimed += reclaim_state->reclaimed_slab;
@@ -3367,10 +3374,9 @@ static int __zone_reclaim(struct zone *zone, gfp_t gfp_mask, unsigned int order)
* number of slab pages and shake the slab until it is reduced
* by the same nr_pages that we used for reclaiming unmapped
* pages.
- *
- * Note that shrink_slab will free memory on all zones and may
- * take a long time.
*/
+ nodes_clear(shrink.nodes_to_scan);
+ node_set(zone_to_nid(zone), shrink.nodes_to_scan);
for (;;) {
unsigned long lru_pages = zone_reclaimable_pages(zone);
--
1.8.1.4
^ permalink raw reply related [flat|nested] 151+ messages in thread* [PATCH v6 11/31] shrinker: add node awareness
@ 2013-05-12 18:13 ` Glauber Costa
0 siblings, 0 replies; 151+ messages in thread
From: Glauber Costa @ 2013-05-12 18:13 UTC (permalink / raw)
To: linux-mm
Cc: cgroups, Andrew Morton, Greg Thelen, kamezawa.hiroyu,
Michal Hocko, Johannes Weiner, linux-fsdevel, Dave Chinner,
Dave Chinner, Glauber Costa
From: Dave Chinner <dchinner@redhat.com>
Pass the node of the current zone being reclaimed to shrink_slab(),
allowing the shrinker control nodemask to be set appropriately for
node aware shrinkers.
[ v3: update ashmem ]
Signed-off-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Glauber Costa <glommer@openvz.org>
Acked-by: Mel Gorman <mgorman@suse.de>
---
drivers/staging/android/ashmem.c | 3 +++
fs/drop_caches.c | 1 +
include/linux/shrinker.h | 3 +++
mm/memory-failure.c | 2 ++
mm/vmscan.c | 12 +++++++++---
5 files changed, 18 insertions(+), 3 deletions(-)
diff --git a/drivers/staging/android/ashmem.c b/drivers/staging/android/ashmem.c
index e681bdd..3240d34 100644
--- a/drivers/staging/android/ashmem.c
+++ b/drivers/staging/android/ashmem.c
@@ -692,6 +692,9 @@ static long ashmem_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
.gfp_mask = GFP_KERNEL,
.nr_to_scan = 0,
};
+
+ nodes_setall(sc.nodes_to_scan);
+
ret = ashmem_shrink(&ashmem_shrinker, &sc);
sc.nr_to_scan = ret;
ashmem_shrink(&ashmem_shrinker, &sc);
diff --git a/fs/drop_caches.c b/fs/drop_caches.c
index f23d2a7..c3f44e7 100644
--- a/fs/drop_caches.c
+++ b/fs/drop_caches.c
@@ -44,6 +44,7 @@ static void drop_slab(void)
.gfp_mask = GFP_KERNEL,
};
+ nodes_setall(shrink.nodes_to_scan);
do {
nr_objects = shrink_slab(&shrink, 1000, 1000);
} while (nr_objects > 10);
diff --git a/include/linux/shrinker.h b/include/linux/shrinker.h
index c277b4e..98be3ab 100644
--- a/include/linux/shrinker.h
+++ b/include/linux/shrinker.h
@@ -16,6 +16,9 @@ struct shrink_control {
/* How many slab objects shrinker() should scan and try to reclaim */
long nr_to_scan;
+
+ /* shrink from these nodes */
+ nodemask_t nodes_to_scan;
};
/*
diff --git a/mm/memory-failure.c b/mm/memory-failure.c
index ceb0c7f..86788ff 100644
--- a/mm/memory-failure.c
+++ b/mm/memory-failure.c
@@ -248,10 +248,12 @@ void shake_page(struct page *p, int access)
*/
if (access) {
int nr;
+ int nid = page_to_nid(p);
do {
struct shrink_control shrink = {
.gfp_mask = GFP_KERNEL,
};
+ node_set(nid, shrink.nodes_to_scan);
nr = shrink_slab(&shrink, 1000, 1000);
if (page_count(p) == 1)
diff --git a/mm/vmscan.c b/mm/vmscan.c
index fd4639c..35a6a9b 100644
--- a/mm/vmscan.c
+++ b/mm/vmscan.c
@@ -2198,15 +2198,20 @@ static unsigned long do_try_to_free_pages(struct zonelist *zonelist,
*/
if (global_reclaim(sc)) {
unsigned long lru_pages = 0;
+
+ nodes_clear(shrink->nodes_to_scan);
for_each_zone_zonelist(zone, z, zonelist,
gfp_zone(sc->gfp_mask)) {
if (!cpuset_zone_allowed_hardwall(zone, GFP_KERNEL))
continue;
lru_pages += zone_reclaimable_pages(zone);
+ node_set(zone_to_nid(zone),
+ shrink->nodes_to_scan);
}
shrink_slab(shrink, sc->nr_scanned, lru_pages);
+
if (reclaim_state) {
sc->nr_reclaimed += reclaim_state->reclaimed_slab;
reclaim_state->reclaimed_slab = 0;
@@ -2782,6 +2787,8 @@ loop_again:
shrink_zone(zone, &sc);
reclaim_state->reclaimed_slab = 0;
+ nodes_clear(shrink.nodes_to_scan);
+ node_set(zone_to_nid(zone), shrink.nodes_to_scan);
nr_slab = shrink_slab(&shrink, sc.nr_scanned, lru_pages);
sc.nr_reclaimed += reclaim_state->reclaimed_slab;
@@ -3367,10 +3374,9 @@ static int __zone_reclaim(struct zone *zone, gfp_t gfp_mask, unsigned int order)
* number of slab pages and shake the slab until it is reduced
* by the same nr_pages that we used for reclaiming unmapped
* pages.
- *
- * Note that shrink_slab will free memory on all zones and may
- * take a long time.
*/
+ nodes_clear(shrink.nodes_to_scan);
+ node_set(zone_to_nid(zone), shrink.nodes_to_scan);
for (;;) {
unsigned long lru_pages = zone_reclaimable_pages(zone);
--
1.8.1.4
^ permalink raw reply related [flat|nested] 151+ messages in thread* [PATCH v6 11/31] shrinker: add node awareness
@ 2013-05-12 18:13 ` Glauber Costa
0 siblings, 0 replies; 151+ messages in thread
From: Glauber Costa @ 2013-05-12 18:13 UTC (permalink / raw)
To: linux-mm
Cc: cgroups, Andrew Morton, Greg Thelen, kamezawa.hiroyu,
Michal Hocko, Johannes Weiner, linux-fsdevel, Dave Chinner,
Dave Chinner, Glauber Costa
From: Dave Chinner <dchinner@redhat.com>
Pass the node of the current zone being reclaimed to shrink_slab(),
allowing the shrinker control nodemask to be set appropriately for
node aware shrinkers.
[ v3: update ashmem ]
Signed-off-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Glauber Costa <glommer@openvz.org>
Acked-by: Mel Gorman <mgorman@suse.de>
---
drivers/staging/android/ashmem.c | 3 +++
fs/drop_caches.c | 1 +
include/linux/shrinker.h | 3 +++
mm/memory-failure.c | 2 ++
mm/vmscan.c | 12 +++++++++---
5 files changed, 18 insertions(+), 3 deletions(-)
diff --git a/drivers/staging/android/ashmem.c b/drivers/staging/android/ashmem.c
index e681bdd..3240d34 100644
--- a/drivers/staging/android/ashmem.c
+++ b/drivers/staging/android/ashmem.c
@@ -692,6 +692,9 @@ static long ashmem_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
.gfp_mask = GFP_KERNEL,
.nr_to_scan = 0,
};
+
+ nodes_setall(sc.nodes_to_scan);
+
ret = ashmem_shrink(&ashmem_shrinker, &sc);
sc.nr_to_scan = ret;
ashmem_shrink(&ashmem_shrinker, &sc);
diff --git a/fs/drop_caches.c b/fs/drop_caches.c
index f23d2a7..c3f44e7 100644
--- a/fs/drop_caches.c
+++ b/fs/drop_caches.c
@@ -44,6 +44,7 @@ static void drop_slab(void)
.gfp_mask = GFP_KERNEL,
};
+ nodes_setall(shrink.nodes_to_scan);
do {
nr_objects = shrink_slab(&shrink, 1000, 1000);
} while (nr_objects > 10);
diff --git a/include/linux/shrinker.h b/include/linux/shrinker.h
index c277b4e..98be3ab 100644
--- a/include/linux/shrinker.h
+++ b/include/linux/shrinker.h
@@ -16,6 +16,9 @@ struct shrink_control {
/* How many slab objects shrinker() should scan and try to reclaim */
long nr_to_scan;
+
+ /* shrink from these nodes */
+ nodemask_t nodes_to_scan;
};
/*
diff --git a/mm/memory-failure.c b/mm/memory-failure.c
index ceb0c7f..86788ff 100644
--- a/mm/memory-failure.c
+++ b/mm/memory-failure.c
@@ -248,10 +248,12 @@ void shake_page(struct page *p, int access)
*/
if (access) {
int nr;
+ int nid = page_to_nid(p);
do {
struct shrink_control shrink = {
.gfp_mask = GFP_KERNEL,
};
+ node_set(nid, shrink.nodes_to_scan);
nr = shrink_slab(&shrink, 1000, 1000);
if (page_count(p) == 1)
diff --git a/mm/vmscan.c b/mm/vmscan.c
index fd4639c..35a6a9b 100644
--- a/mm/vmscan.c
+++ b/mm/vmscan.c
@@ -2198,15 +2198,20 @@ static unsigned long do_try_to_free_pages(struct zonelist *zonelist,
*/
if (global_reclaim(sc)) {
unsigned long lru_pages = 0;
+
+ nodes_clear(shrink->nodes_to_scan);
for_each_zone_zonelist(zone, z, zonelist,
gfp_zone(sc->gfp_mask)) {
if (!cpuset_zone_allowed_hardwall(zone, GFP_KERNEL))
continue;
lru_pages += zone_reclaimable_pages(zone);
+ node_set(zone_to_nid(zone),
+ shrink->nodes_to_scan);
}
shrink_slab(shrink, sc->nr_scanned, lru_pages);
+
if (reclaim_state) {
sc->nr_reclaimed += reclaim_state->reclaimed_slab;
reclaim_state->reclaimed_slab = 0;
@@ -2782,6 +2787,8 @@ loop_again:
shrink_zone(zone, &sc);
reclaim_state->reclaimed_slab = 0;
+ nodes_clear(shrink.nodes_to_scan);
+ node_set(zone_to_nid(zone), shrink.nodes_to_scan);
nr_slab = shrink_slab(&shrink, sc.nr_scanned, lru_pages);
sc.nr_reclaimed += reclaim_state->reclaimed_slab;
@@ -3367,10 +3374,9 @@ static int __zone_reclaim(struct zone *zone, gfp_t gfp_mask, unsigned int order)
* number of slab pages and shake the slab until it is reduced
* by the same nr_pages that we used for reclaiming unmapped
* pages.
- *
- * Note that shrink_slab will free memory on all zones and may
- * take a long time.
*/
+ nodes_clear(shrink.nodes_to_scan);
+ node_set(zone_to_nid(zone), shrink.nodes_to_scan);
for (;;) {
unsigned long lru_pages = zone_reclaimable_pages(zone);
--
1.8.1.4
--
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^ permalink raw reply related [flat|nested] 151+ messages in thread
* [PATCH v6 12/31] fs: convert inode and dentry shrinking to be node aware
2013-05-12 18:13 ` Glauber Costa
(?)
@ 2013-05-12 18:13 ` Glauber Costa
-1 siblings, 0 replies; 151+ messages in thread
From: Glauber Costa @ 2013-05-12 18:13 UTC (permalink / raw)
To: linux-mm
Cc: cgroups, Andrew Morton, Greg Thelen, kamezawa.hiroyu,
Michal Hocko, Johannes Weiner, linux-fsdevel, Dave Chinner,
Dave Chinner, Glauber Costa
From: Dave Chinner <dchinner@redhat.com>
Now that the shrinker is passing a nodemask in the scan control
structure, we can pass this to the the generic LRU list code to
isolate reclaim to the lists on matching nodes.
This requires a small amount of refactoring of the LRU list API,
which might be best split out into a separate patch.
Signed-off-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Glauber Costa <glommer@parallels.com>
Acked-by: Mel Gorman <mgorman@suse.de>
---
fs/dcache.c | 8 +++++---
fs/inode.c | 7 ++++---
fs/internal.h | 6 ++++--
fs/super.c | 22 +++++++++++++---------
fs/xfs/xfs_super.c | 6 ++++--
include/linux/fs.h | 4 ++--
include/linux/list_lru.h | 22 +++++++++++++++++++---
lib/list_lru.c | 15 ++++++++-------
8 files changed, 59 insertions(+), 31 deletions(-)
diff --git a/fs/dcache.c b/fs/dcache.c
index ba14661..20ab9c0 100644
--- a/fs/dcache.c
+++ b/fs/dcache.c
@@ -875,6 +875,7 @@ dentry_lru_isolate(struct list_head *item, spinlock_t *lru_lock, void *arg)
* prune_dcache_sb - shrink the dcache
* @sb: superblock
* @nr_to_scan : number of entries to try to free
+ * @nodes_to_walk: which nodes to scan for freeable entities
*
* Attempt to shrink the superblock dcache LRU by @nr_to_scan entries. This is
* done when we need more memory an called from the superblock shrinker
@@ -883,13 +884,14 @@ dentry_lru_isolate(struct list_head *item, spinlock_t *lru_lock, void *arg)
* This function may fail to free any resources if all the dentries are in
* use.
*/
-long prune_dcache_sb(struct super_block *sb, unsigned long nr_to_scan)
+long prune_dcache_sb(struct super_block *sb, unsigned long nr_to_scan,
+ nodemask_t *nodes_to_walk)
{
LIST_HEAD(dispose);
long freed;
- freed = list_lru_walk(&sb->s_dentry_lru, dentry_lru_isolate,
- &dispose, nr_to_scan);
+ freed = list_lru_walk_nodemask(&sb->s_dentry_lru, dentry_lru_isolate,
+ &dispose, nr_to_scan, nodes_to_walk);
shrink_dentry_list(&dispose);
return freed;
}
diff --git a/fs/inode.c b/fs/inode.c
index ff66f49..3cf4cb0 100644
--- a/fs/inode.c
+++ b/fs/inode.c
@@ -746,13 +746,14 @@ inode_lru_isolate(struct list_head *item, spinlock_t *lru_lock, void *arg)
* to trim from the LRU. Inodes to be freed are moved to a temporary list and
* then are freed outside inode_lock by dispose_list().
*/
-long prune_icache_sb(struct super_block *sb, unsigned long nr_to_scan)
+long prune_icache_sb(struct super_block *sb, unsigned long nr_to_scan,
+ nodemask_t *nodes_to_walk)
{
LIST_HEAD(freeable);
long freed;
- freed = list_lru_walk(&sb->s_inode_lru, inode_lru_isolate,
- &freeable, nr_to_scan);
+ freed = list_lru_walk_nodemask(&sb->s_inode_lru, inode_lru_isolate,
+ &freeable, nr_to_scan, nodes_to_walk);
dispose_list(&freeable);
return freed;
}
diff --git a/fs/internal.h b/fs/internal.h
index bb7b6e4..91900f2 100644
--- a/fs/internal.h
+++ b/fs/internal.h
@@ -110,7 +110,8 @@ extern int open_check_o_direct(struct file *f);
* inode.c
*/
extern spinlock_t inode_sb_list_lock;
-extern long prune_icache_sb(struct super_block *sb, unsigned long nr_to_scan);
+extern long prune_icache_sb(struct super_block *sb, unsigned long nr_to_scan,
+ nodemask_t *nodes_to_scan);
extern void inode_add_lru(struct inode *inode);
/*
@@ -126,7 +127,8 @@ extern int invalidate_inodes(struct super_block *, bool);
* dcache.c
*/
extern struct dentry *__d_alloc(struct super_block *, const struct qstr *);
-extern long prune_dcache_sb(struct super_block *sb, unsigned long nr_to_scan);
+extern long prune_dcache_sb(struct super_block *sb, unsigned long nr_to_scan,
+ nodemask_t *nodes_to_scan);
/*
* read_write.c
diff --git a/fs/super.c b/fs/super.c
index 66f5cde..5c7b879 100644
--- a/fs/super.c
+++ b/fs/super.c
@@ -75,10 +75,10 @@ static long super_cache_scan(struct shrinker *shrink, struct shrink_control *sc)
return -1;
if (sb->s_op && sb->s_op->nr_cached_objects)
- fs_objects = sb->s_op->nr_cached_objects(sb);
+ fs_objects = sb->s_op->nr_cached_objects(sb, &sc->nodes_to_scan);
- inodes = list_lru_count(&sb->s_inode_lru);
- dentries = list_lru_count(&sb->s_dentry_lru);
+ inodes = list_lru_count_nodemask(&sb->s_inode_lru, &sc->nodes_to_scan);
+ dentries = list_lru_count_nodemask(&sb->s_dentry_lru, &sc->nodes_to_scan);
total_objects = dentries + inodes + fs_objects + 1;
/* proportion the scan between the caches */
@@ -89,13 +89,14 @@ static long super_cache_scan(struct shrinker *shrink, struct shrink_control *sc)
* prune the dcache first as the icache is pinned by it, then
* prune the icache, followed by the filesystem specific caches
*/
- freed = prune_dcache_sb(sb, dentries);
- freed += prune_icache_sb(sb, inodes);
+ freed = prune_dcache_sb(sb, dentries, &sc->nodes_to_scan);
+ freed += prune_icache_sb(sb, inodes, &sc->nodes_to_scan);
if (fs_objects) {
fs_objects = mult_frac(sc->nr_to_scan, fs_objects,
total_objects);
- freed += sb->s_op->free_cached_objects(sb, fs_objects);
+ freed += sb->s_op->free_cached_objects(sb, fs_objects,
+ &sc->nodes_to_scan);
}
drop_super(sb);
@@ -113,10 +114,13 @@ static long super_cache_count(struct shrinker *shrink, struct shrink_control *sc
return -1;
if (sb->s_op && sb->s_op->nr_cached_objects)
- total_objects = sb->s_op->nr_cached_objects(sb);
+ total_objects = sb->s_op->nr_cached_objects(sb,
+ &sc->nodes_to_scan);
- total_objects += list_lru_count(&sb->s_dentry_lru);
- total_objects += list_lru_count(&sb->s_inode_lru);
+ total_objects += list_lru_count_nodemask(&sb->s_dentry_lru,
+ &sc->nodes_to_scan);
+ total_objects += list_lru_count_nodemask(&sb->s_inode_lru,
+ &sc->nodes_to_scan);
total_objects = vfs_pressure_ratio(total_objects);
drop_super(sb);
diff --git a/fs/xfs/xfs_super.c b/fs/xfs/xfs_super.c
index 1ff991b..7fa60214 100644
--- a/fs/xfs/xfs_super.c
+++ b/fs/xfs/xfs_super.c
@@ -1525,7 +1525,8 @@ xfs_fs_mount(
static long
xfs_fs_nr_cached_objects(
- struct super_block *sb)
+ struct super_block *sb,
+ nodemask_t *nodes_to_count)
{
return xfs_reclaim_inodes_count(XFS_M(sb));
}
@@ -1533,7 +1534,8 @@ xfs_fs_nr_cached_objects(
static long
xfs_fs_free_cached_objects(
struct super_block *sb,
- long nr_to_scan)
+ long nr_to_scan,
+ nodemask_t *nodes_to_scan)
{
return xfs_reclaim_inodes_nr(XFS_M(sb), nr_to_scan);
}
diff --git a/include/linux/fs.h b/include/linux/fs.h
index 02b3612..d548724 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -1609,8 +1609,8 @@ struct super_operations {
ssize_t (*quota_write)(struct super_block *, int, const char *, size_t, loff_t);
#endif
int (*bdev_try_to_free_page)(struct super_block*, struct page*, gfp_t);
- long (*nr_cached_objects)(struct super_block *);
- long (*free_cached_objects)(struct super_block *, long);
+ long (*nr_cached_objects)(struct super_block *, nodemask_t *);
+ long (*free_cached_objects)(struct super_block *, long, nodemask_t *);
};
/*
diff --git a/include/linux/list_lru.h b/include/linux/list_lru.h
index 668f1f1..f5e3c15 100644
--- a/include/linux/list_lru.h
+++ b/include/linux/list_lru.h
@@ -42,15 +42,31 @@ struct list_lru {
int list_lru_init(struct list_lru *lru);
int list_lru_add(struct list_lru *lru, struct list_head *item);
int list_lru_del(struct list_lru *lru, struct list_head *item);
-unsigned long list_lru_count(struct list_lru *lru);
+unsigned long
+list_lru_count_nodemask(struct list_lru *lru, nodemask_t *nodes_to_count);
+
+static inline unsigned long list_lru_count(struct list_lru *lru)
+{
+ return list_lru_count_nodemask(lru, &lru->active_nodes);
+}
+
typedef enum lru_status
(*list_lru_walk_cb)(struct list_head *item, spinlock_t *lock, void *cb_arg);
typedef void (*list_lru_dispose_cb)(struct list_head *dispose_list);
-unsigned long list_lru_walk(struct list_lru *lru, list_lru_walk_cb isolate,
- void *cb_arg, unsigned long nr_to_walk);
+unsigned long
+list_lru_walk_nodemask(struct list_lru *lru, list_lru_walk_cb isolate,
+ void *cb_arg, unsigned long nr_to_walk, nodemask_t *nodes_to_walk);
+
+static inline unsigned long
+list_lru_walk(struct list_lru *lru, list_lru_walk_cb isolate,
+ void *cb_arg, unsigned long nr_to_walk)
+{
+ return list_lru_walk_nodemask(lru, isolate, cb_arg, nr_to_walk,
+ &lru->active_nodes);
+}
unsigned long
list_lru_dispose_all(struct list_lru *lru, list_lru_dispose_cb dispose);
diff --git a/lib/list_lru.c b/lib/list_lru.c
index 6d43079..248be3b 100644
--- a/lib/list_lru.c
+++ b/lib/list_lru.c
@@ -54,12 +54,12 @@ list_lru_del(
EXPORT_SYMBOL_GPL(list_lru_del);
unsigned long
-list_lru_count(struct list_lru *lru)
+list_lru_count_nodemask(struct list_lru *lru, nodemask_t *nodes_to_count)
{
long count = 0;
int nid;
- for_each_node_mask(nid, lru->active_nodes) {
+ for_each_node_mask(nid, *nodes_to_count) {
struct list_lru_node *nlru = &lru->node[nid];
spin_lock(&nlru->lock);
@@ -70,7 +70,7 @@ list_lru_count(struct list_lru *lru)
return count;
}
-EXPORT_SYMBOL_GPL(list_lru_count);
+EXPORT_SYMBOL_GPL(list_lru_count_nodemask);
static unsigned long
list_lru_walk_node(
@@ -119,16 +119,17 @@ restart:
}
unsigned long
-list_lru_walk(
+list_lru_walk_nodemask(
struct list_lru *lru,
list_lru_walk_cb isolate,
void *cb_arg,
- unsigned long nr_to_walk)
+ unsigned long nr_to_walk,
+ nodemask_t *nodes_to_walk)
{
long isolated = 0;
int nid;
- for_each_node_mask(nid, lru->active_nodes) {
+ for_each_node_mask(nid, *nodes_to_walk) {
isolated += list_lru_walk_node(lru, nid, isolate,
cb_arg, &nr_to_walk);
if (nr_to_walk <= 0)
@@ -136,7 +137,7 @@ list_lru_walk(
}
return isolated;
}
-EXPORT_SYMBOL_GPL(list_lru_walk);
+EXPORT_SYMBOL_GPL(list_lru_walk_nodemask);
static unsigned long
list_lru_dispose_all_node(
--
1.8.1.4
^ permalink raw reply related [flat|nested] 151+ messages in thread* [PATCH v6 12/31] fs: convert inode and dentry shrinking to be node aware
@ 2013-05-12 18:13 ` Glauber Costa
0 siblings, 0 replies; 151+ messages in thread
From: Glauber Costa @ 2013-05-12 18:13 UTC (permalink / raw)
To: linux-mm
Cc: cgroups, Andrew Morton, Greg Thelen, kamezawa.hiroyu,
Michal Hocko, Johannes Weiner, linux-fsdevel, Dave Chinner,
Dave Chinner, Glauber Costa
From: Dave Chinner <dchinner@redhat.com>
Now that the shrinker is passing a nodemask in the scan control
structure, we can pass this to the the generic LRU list code to
isolate reclaim to the lists on matching nodes.
This requires a small amount of refactoring of the LRU list API,
which might be best split out into a separate patch.
Signed-off-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Glauber Costa <glommer@parallels.com>
Acked-by: Mel Gorman <mgorman@suse.de>
---
fs/dcache.c | 8 +++++---
fs/inode.c | 7 ++++---
fs/internal.h | 6 ++++--
fs/super.c | 22 +++++++++++++---------
fs/xfs/xfs_super.c | 6 ++++--
include/linux/fs.h | 4 ++--
include/linux/list_lru.h | 22 +++++++++++++++++++---
lib/list_lru.c | 15 ++++++++-------
8 files changed, 59 insertions(+), 31 deletions(-)
diff --git a/fs/dcache.c b/fs/dcache.c
index ba14661..20ab9c0 100644
--- a/fs/dcache.c
+++ b/fs/dcache.c
@@ -875,6 +875,7 @@ dentry_lru_isolate(struct list_head *item, spinlock_t *lru_lock, void *arg)
* prune_dcache_sb - shrink the dcache
* @sb: superblock
* @nr_to_scan : number of entries to try to free
+ * @nodes_to_walk: which nodes to scan for freeable entities
*
* Attempt to shrink the superblock dcache LRU by @nr_to_scan entries. This is
* done when we need more memory an called from the superblock shrinker
@@ -883,13 +884,14 @@ dentry_lru_isolate(struct list_head *item, spinlock_t *lru_lock, void *arg)
* This function may fail to free any resources if all the dentries are in
* use.
*/
-long prune_dcache_sb(struct super_block *sb, unsigned long nr_to_scan)
+long prune_dcache_sb(struct super_block *sb, unsigned long nr_to_scan,
+ nodemask_t *nodes_to_walk)
{
LIST_HEAD(dispose);
long freed;
- freed = list_lru_walk(&sb->s_dentry_lru, dentry_lru_isolate,
- &dispose, nr_to_scan);
+ freed = list_lru_walk_nodemask(&sb->s_dentry_lru, dentry_lru_isolate,
+ &dispose, nr_to_scan, nodes_to_walk);
shrink_dentry_list(&dispose);
return freed;
}
diff --git a/fs/inode.c b/fs/inode.c
index ff66f49..3cf4cb0 100644
--- a/fs/inode.c
+++ b/fs/inode.c
@@ -746,13 +746,14 @@ inode_lru_isolate(struct list_head *item, spinlock_t *lru_lock, void *arg)
* to trim from the LRU. Inodes to be freed are moved to a temporary list and
* then are freed outside inode_lock by dispose_list().
*/
-long prune_icache_sb(struct super_block *sb, unsigned long nr_to_scan)
+long prune_icache_sb(struct super_block *sb, unsigned long nr_to_scan,
+ nodemask_t *nodes_to_walk)
{
LIST_HEAD(freeable);
long freed;
- freed = list_lru_walk(&sb->s_inode_lru, inode_lru_isolate,
- &freeable, nr_to_scan);
+ freed = list_lru_walk_nodemask(&sb->s_inode_lru, inode_lru_isolate,
+ &freeable, nr_to_scan, nodes_to_walk);
dispose_list(&freeable);
return freed;
}
diff --git a/fs/internal.h b/fs/internal.h
index bb7b6e4..91900f2 100644
--- a/fs/internal.h
+++ b/fs/internal.h
@@ -110,7 +110,8 @@ extern int open_check_o_direct(struct file *f);
* inode.c
*/
extern spinlock_t inode_sb_list_lock;
-extern long prune_icache_sb(struct super_block *sb, unsigned long nr_to_scan);
+extern long prune_icache_sb(struct super_block *sb, unsigned long nr_to_scan,
+ nodemask_t *nodes_to_scan);
extern void inode_add_lru(struct inode *inode);
/*
@@ -126,7 +127,8 @@ extern int invalidate_inodes(struct super_block *, bool);
* dcache.c
*/
extern struct dentry *__d_alloc(struct super_block *, const struct qstr *);
-extern long prune_dcache_sb(struct super_block *sb, unsigned long nr_to_scan);
+extern long prune_dcache_sb(struct super_block *sb, unsigned long nr_to_scan,
+ nodemask_t *nodes_to_scan);
/*
* read_write.c
diff --git a/fs/super.c b/fs/super.c
index 66f5cde..5c7b879 100644
--- a/fs/super.c
+++ b/fs/super.c
@@ -75,10 +75,10 @@ static long super_cache_scan(struct shrinker *shrink, struct shrink_control *sc)
return -1;
if (sb->s_op && sb->s_op->nr_cached_objects)
- fs_objects = sb->s_op->nr_cached_objects(sb);
+ fs_objects = sb->s_op->nr_cached_objects(sb, &sc->nodes_to_scan);
- inodes = list_lru_count(&sb->s_inode_lru);
- dentries = list_lru_count(&sb->s_dentry_lru);
+ inodes = list_lru_count_nodemask(&sb->s_inode_lru, &sc->nodes_to_scan);
+ dentries = list_lru_count_nodemask(&sb->s_dentry_lru, &sc->nodes_to_scan);
total_objects = dentries + inodes + fs_objects + 1;
/* proportion the scan between the caches */
@@ -89,13 +89,14 @@ static long super_cache_scan(struct shrinker *shrink, struct shrink_control *sc)
* prune the dcache first as the icache is pinned by it, then
* prune the icache, followed by the filesystem specific caches
*/
- freed = prune_dcache_sb(sb, dentries);
- freed += prune_icache_sb(sb, inodes);
+ freed = prune_dcache_sb(sb, dentries, &sc->nodes_to_scan);
+ freed += prune_icache_sb(sb, inodes, &sc->nodes_to_scan);
if (fs_objects) {
fs_objects = mult_frac(sc->nr_to_scan, fs_objects,
total_objects);
- freed += sb->s_op->free_cached_objects(sb, fs_objects);
+ freed += sb->s_op->free_cached_objects(sb, fs_objects,
+ &sc->nodes_to_scan);
}
drop_super(sb);
@@ -113,10 +114,13 @@ static long super_cache_count(struct shrinker *shrink, struct shrink_control *sc
return -1;
if (sb->s_op && sb->s_op->nr_cached_objects)
- total_objects = sb->s_op->nr_cached_objects(sb);
+ total_objects = sb->s_op->nr_cached_objects(sb,
+ &sc->nodes_to_scan);
- total_objects += list_lru_count(&sb->s_dentry_lru);
- total_objects += list_lru_count(&sb->s_inode_lru);
+ total_objects += list_lru_count_nodemask(&sb->s_dentry_lru,
+ &sc->nodes_to_scan);
+ total_objects += list_lru_count_nodemask(&sb->s_inode_lru,
+ &sc->nodes_to_scan);
total_objects = vfs_pressure_ratio(total_objects);
drop_super(sb);
diff --git a/fs/xfs/xfs_super.c b/fs/xfs/xfs_super.c
index 1ff991b..7fa60214 100644
--- a/fs/xfs/xfs_super.c
+++ b/fs/xfs/xfs_super.c
@@ -1525,7 +1525,8 @@ xfs_fs_mount(
static long
xfs_fs_nr_cached_objects(
- struct super_block *sb)
+ struct super_block *sb,
+ nodemask_t *nodes_to_count)
{
return xfs_reclaim_inodes_count(XFS_M(sb));
}
@@ -1533,7 +1534,8 @@ xfs_fs_nr_cached_objects(
static long
xfs_fs_free_cached_objects(
struct super_block *sb,
- long nr_to_scan)
+ long nr_to_scan,
+ nodemask_t *nodes_to_scan)
{
return xfs_reclaim_inodes_nr(XFS_M(sb), nr_to_scan);
}
diff --git a/include/linux/fs.h b/include/linux/fs.h
index 02b3612..d548724 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -1609,8 +1609,8 @@ struct super_operations {
ssize_t (*quota_write)(struct super_block *, int, const char *, size_t, loff_t);
#endif
int (*bdev_try_to_free_page)(struct super_block*, struct page*, gfp_t);
- long (*nr_cached_objects)(struct super_block *);
- long (*free_cached_objects)(struct super_block *, long);
+ long (*nr_cached_objects)(struct super_block *, nodemask_t *);
+ long (*free_cached_objects)(struct super_block *, long, nodemask_t *);
};
/*
diff --git a/include/linux/list_lru.h b/include/linux/list_lru.h
index 668f1f1..f5e3c15 100644
--- a/include/linux/list_lru.h
+++ b/include/linux/list_lru.h
@@ -42,15 +42,31 @@ struct list_lru {
int list_lru_init(struct list_lru *lru);
int list_lru_add(struct list_lru *lru, struct list_head *item);
int list_lru_del(struct list_lru *lru, struct list_head *item);
-unsigned long list_lru_count(struct list_lru *lru);
+unsigned long
+list_lru_count_nodemask(struct list_lru *lru, nodemask_t *nodes_to_count);
+
+static inline unsigned long list_lru_count(struct list_lru *lru)
+{
+ return list_lru_count_nodemask(lru, &lru->active_nodes);
+}
+
typedef enum lru_status
(*list_lru_walk_cb)(struct list_head *item, spinlock_t *lock, void *cb_arg);
typedef void (*list_lru_dispose_cb)(struct list_head *dispose_list);
-unsigned long list_lru_walk(struct list_lru *lru, list_lru_walk_cb isolate,
- void *cb_arg, unsigned long nr_to_walk);
+unsigned long
+list_lru_walk_nodemask(struct list_lru *lru, list_lru_walk_cb isolate,
+ void *cb_arg, unsigned long nr_to_walk, nodemask_t *nodes_to_walk);
+
+static inline unsigned long
+list_lru_walk(struct list_lru *lru, list_lru_walk_cb isolate,
+ void *cb_arg, unsigned long nr_to_walk)
+{
+ return list_lru_walk_nodemask(lru, isolate, cb_arg, nr_to_walk,
+ &lru->active_nodes);
+}
unsigned long
list_lru_dispose_all(struct list_lru *lru, list_lru_dispose_cb dispose);
diff --git a/lib/list_lru.c b/lib/list_lru.c
index 6d43079..248be3b 100644
--- a/lib/list_lru.c
+++ b/lib/list_lru.c
@@ -54,12 +54,12 @@ list_lru_del(
EXPORT_SYMBOL_GPL(list_lru_del);
unsigned long
-list_lru_count(struct list_lru *lru)
+list_lru_count_nodemask(struct list_lru *lru, nodemask_t *nodes_to_count)
{
long count = 0;
int nid;
- for_each_node_mask(nid, lru->active_nodes) {
+ for_each_node_mask(nid, *nodes_to_count) {
struct list_lru_node *nlru = &lru->node[nid];
spin_lock(&nlru->lock);
@@ -70,7 +70,7 @@ list_lru_count(struct list_lru *lru)
return count;
}
-EXPORT_SYMBOL_GPL(list_lru_count);
+EXPORT_SYMBOL_GPL(list_lru_count_nodemask);
static unsigned long
list_lru_walk_node(
@@ -119,16 +119,17 @@ restart:
}
unsigned long
-list_lru_walk(
+list_lru_walk_nodemask(
struct list_lru *lru,
list_lru_walk_cb isolate,
void *cb_arg,
- unsigned long nr_to_walk)
+ unsigned long nr_to_walk,
+ nodemask_t *nodes_to_walk)
{
long isolated = 0;
int nid;
- for_each_node_mask(nid, lru->active_nodes) {
+ for_each_node_mask(nid, *nodes_to_walk) {
isolated += list_lru_walk_node(lru, nid, isolate,
cb_arg, &nr_to_walk);
if (nr_to_walk <= 0)
@@ -136,7 +137,7 @@ list_lru_walk(
}
return isolated;
}
-EXPORT_SYMBOL_GPL(list_lru_walk);
+EXPORT_SYMBOL_GPL(list_lru_walk_nodemask);
static unsigned long
list_lru_dispose_all_node(
--
1.8.1.4
^ permalink raw reply related [flat|nested] 151+ messages in thread* [PATCH v6 12/31] fs: convert inode and dentry shrinking to be node aware
@ 2013-05-12 18:13 ` Glauber Costa
0 siblings, 0 replies; 151+ messages in thread
From: Glauber Costa @ 2013-05-12 18:13 UTC (permalink / raw)
To: linux-mm
Cc: cgroups, Andrew Morton, Greg Thelen, kamezawa.hiroyu,
Michal Hocko, Johannes Weiner, linux-fsdevel, Dave Chinner,
Dave Chinner, Glauber Costa
From: Dave Chinner <dchinner@redhat.com>
Now that the shrinker is passing a nodemask in the scan control
structure, we can pass this to the the generic LRU list code to
isolate reclaim to the lists on matching nodes.
This requires a small amount of refactoring of the LRU list API,
which might be best split out into a separate patch.
Signed-off-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Glauber Costa <glommer@parallels.com>
Acked-by: Mel Gorman <mgorman@suse.de>
---
fs/dcache.c | 8 +++++---
fs/inode.c | 7 ++++---
fs/internal.h | 6 ++++--
fs/super.c | 22 +++++++++++++---------
fs/xfs/xfs_super.c | 6 ++++--
include/linux/fs.h | 4 ++--
include/linux/list_lru.h | 22 +++++++++++++++++++---
lib/list_lru.c | 15 ++++++++-------
8 files changed, 59 insertions(+), 31 deletions(-)
diff --git a/fs/dcache.c b/fs/dcache.c
index ba14661..20ab9c0 100644
--- a/fs/dcache.c
+++ b/fs/dcache.c
@@ -875,6 +875,7 @@ dentry_lru_isolate(struct list_head *item, spinlock_t *lru_lock, void *arg)
* prune_dcache_sb - shrink the dcache
* @sb: superblock
* @nr_to_scan : number of entries to try to free
+ * @nodes_to_walk: which nodes to scan for freeable entities
*
* Attempt to shrink the superblock dcache LRU by @nr_to_scan entries. This is
* done when we need more memory an called from the superblock shrinker
@@ -883,13 +884,14 @@ dentry_lru_isolate(struct list_head *item, spinlock_t *lru_lock, void *arg)
* This function may fail to free any resources if all the dentries are in
* use.
*/
-long prune_dcache_sb(struct super_block *sb, unsigned long nr_to_scan)
+long prune_dcache_sb(struct super_block *sb, unsigned long nr_to_scan,
+ nodemask_t *nodes_to_walk)
{
LIST_HEAD(dispose);
long freed;
- freed = list_lru_walk(&sb->s_dentry_lru, dentry_lru_isolate,
- &dispose, nr_to_scan);
+ freed = list_lru_walk_nodemask(&sb->s_dentry_lru, dentry_lru_isolate,
+ &dispose, nr_to_scan, nodes_to_walk);
shrink_dentry_list(&dispose);
return freed;
}
diff --git a/fs/inode.c b/fs/inode.c
index ff66f49..3cf4cb0 100644
--- a/fs/inode.c
+++ b/fs/inode.c
@@ -746,13 +746,14 @@ inode_lru_isolate(struct list_head *item, spinlock_t *lru_lock, void *arg)
* to trim from the LRU. Inodes to be freed are moved to a temporary list and
* then are freed outside inode_lock by dispose_list().
*/
-long prune_icache_sb(struct super_block *sb, unsigned long nr_to_scan)
+long prune_icache_sb(struct super_block *sb, unsigned long nr_to_scan,
+ nodemask_t *nodes_to_walk)
{
LIST_HEAD(freeable);
long freed;
- freed = list_lru_walk(&sb->s_inode_lru, inode_lru_isolate,
- &freeable, nr_to_scan);
+ freed = list_lru_walk_nodemask(&sb->s_inode_lru, inode_lru_isolate,
+ &freeable, nr_to_scan, nodes_to_walk);
dispose_list(&freeable);
return freed;
}
diff --git a/fs/internal.h b/fs/internal.h
index bb7b6e4..91900f2 100644
--- a/fs/internal.h
+++ b/fs/internal.h
@@ -110,7 +110,8 @@ extern int open_check_o_direct(struct file *f);
* inode.c
*/
extern spinlock_t inode_sb_list_lock;
-extern long prune_icache_sb(struct super_block *sb, unsigned long nr_to_scan);
+extern long prune_icache_sb(struct super_block *sb, unsigned long nr_to_scan,
+ nodemask_t *nodes_to_scan);
extern void inode_add_lru(struct inode *inode);
/*
@@ -126,7 +127,8 @@ extern int invalidate_inodes(struct super_block *, bool);
* dcache.c
*/
extern struct dentry *__d_alloc(struct super_block *, const struct qstr *);
-extern long prune_dcache_sb(struct super_block *sb, unsigned long nr_to_scan);
+extern long prune_dcache_sb(struct super_block *sb, unsigned long nr_to_scan,
+ nodemask_t *nodes_to_scan);
/*
* read_write.c
diff --git a/fs/super.c b/fs/super.c
index 66f5cde..5c7b879 100644
--- a/fs/super.c
+++ b/fs/super.c
@@ -75,10 +75,10 @@ static long super_cache_scan(struct shrinker *shrink, struct shrink_control *sc)
return -1;
if (sb->s_op && sb->s_op->nr_cached_objects)
- fs_objects = sb->s_op->nr_cached_objects(sb);
+ fs_objects = sb->s_op->nr_cached_objects(sb, &sc->nodes_to_scan);
- inodes = list_lru_count(&sb->s_inode_lru);
- dentries = list_lru_count(&sb->s_dentry_lru);
+ inodes = list_lru_count_nodemask(&sb->s_inode_lru, &sc->nodes_to_scan);
+ dentries = list_lru_count_nodemask(&sb->s_dentry_lru, &sc->nodes_to_scan);
total_objects = dentries + inodes + fs_objects + 1;
/* proportion the scan between the caches */
@@ -89,13 +89,14 @@ static long super_cache_scan(struct shrinker *shrink, struct shrink_control *sc)
* prune the dcache first as the icache is pinned by it, then
* prune the icache, followed by the filesystem specific caches
*/
- freed = prune_dcache_sb(sb, dentries);
- freed += prune_icache_sb(sb, inodes);
+ freed = prune_dcache_sb(sb, dentries, &sc->nodes_to_scan);
+ freed += prune_icache_sb(sb, inodes, &sc->nodes_to_scan);
if (fs_objects) {
fs_objects = mult_frac(sc->nr_to_scan, fs_objects,
total_objects);
- freed += sb->s_op->free_cached_objects(sb, fs_objects);
+ freed += sb->s_op->free_cached_objects(sb, fs_objects,
+ &sc->nodes_to_scan);
}
drop_super(sb);
@@ -113,10 +114,13 @@ static long super_cache_count(struct shrinker *shrink, struct shrink_control *sc
return -1;
if (sb->s_op && sb->s_op->nr_cached_objects)
- total_objects = sb->s_op->nr_cached_objects(sb);
+ total_objects = sb->s_op->nr_cached_objects(sb,
+ &sc->nodes_to_scan);
- total_objects += list_lru_count(&sb->s_dentry_lru);
- total_objects += list_lru_count(&sb->s_inode_lru);
+ total_objects += list_lru_count_nodemask(&sb->s_dentry_lru,
+ &sc->nodes_to_scan);
+ total_objects += list_lru_count_nodemask(&sb->s_inode_lru,
+ &sc->nodes_to_scan);
total_objects = vfs_pressure_ratio(total_objects);
drop_super(sb);
diff --git a/fs/xfs/xfs_super.c b/fs/xfs/xfs_super.c
index 1ff991b..7fa60214 100644
--- a/fs/xfs/xfs_super.c
+++ b/fs/xfs/xfs_super.c
@@ -1525,7 +1525,8 @@ xfs_fs_mount(
static long
xfs_fs_nr_cached_objects(
- struct super_block *sb)
+ struct super_block *sb,
+ nodemask_t *nodes_to_count)
{
return xfs_reclaim_inodes_count(XFS_M(sb));
}
@@ -1533,7 +1534,8 @@ xfs_fs_nr_cached_objects(
static long
xfs_fs_free_cached_objects(
struct super_block *sb,
- long nr_to_scan)
+ long nr_to_scan,
+ nodemask_t *nodes_to_scan)
{
return xfs_reclaim_inodes_nr(XFS_M(sb), nr_to_scan);
}
diff --git a/include/linux/fs.h b/include/linux/fs.h
index 02b3612..d548724 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -1609,8 +1609,8 @@ struct super_operations {
ssize_t (*quota_write)(struct super_block *, int, const char *, size_t, loff_t);
#endif
int (*bdev_try_to_free_page)(struct super_block*, struct page*, gfp_t);
- long (*nr_cached_objects)(struct super_block *);
- long (*free_cached_objects)(struct super_block *, long);
+ long (*nr_cached_objects)(struct super_block *, nodemask_t *);
+ long (*free_cached_objects)(struct super_block *, long, nodemask_t *);
};
/*
diff --git a/include/linux/list_lru.h b/include/linux/list_lru.h
index 668f1f1..f5e3c15 100644
--- a/include/linux/list_lru.h
+++ b/include/linux/list_lru.h
@@ -42,15 +42,31 @@ struct list_lru {
int list_lru_init(struct list_lru *lru);
int list_lru_add(struct list_lru *lru, struct list_head *item);
int list_lru_del(struct list_lru *lru, struct list_head *item);
-unsigned long list_lru_count(struct list_lru *lru);
+unsigned long
+list_lru_count_nodemask(struct list_lru *lru, nodemask_t *nodes_to_count);
+
+static inline unsigned long list_lru_count(struct list_lru *lru)
+{
+ return list_lru_count_nodemask(lru, &lru->active_nodes);
+}
+
typedef enum lru_status
(*list_lru_walk_cb)(struct list_head *item, spinlock_t *lock, void *cb_arg);
typedef void (*list_lru_dispose_cb)(struct list_head *dispose_list);
-unsigned long list_lru_walk(struct list_lru *lru, list_lru_walk_cb isolate,
- void *cb_arg, unsigned long nr_to_walk);
+unsigned long
+list_lru_walk_nodemask(struct list_lru *lru, list_lru_walk_cb isolate,
+ void *cb_arg, unsigned long nr_to_walk, nodemask_t *nodes_to_walk);
+
+static inline unsigned long
+list_lru_walk(struct list_lru *lru, list_lru_walk_cb isolate,
+ void *cb_arg, unsigned long nr_to_walk)
+{
+ return list_lru_walk_nodemask(lru, isolate, cb_arg, nr_to_walk,
+ &lru->active_nodes);
+}
unsigned long
list_lru_dispose_all(struct list_lru *lru, list_lru_dispose_cb dispose);
diff --git a/lib/list_lru.c b/lib/list_lru.c
index 6d43079..248be3b 100644
--- a/lib/list_lru.c
+++ b/lib/list_lru.c
@@ -54,12 +54,12 @@ list_lru_del(
EXPORT_SYMBOL_GPL(list_lru_del);
unsigned long
-list_lru_count(struct list_lru *lru)
+list_lru_count_nodemask(struct list_lru *lru, nodemask_t *nodes_to_count)
{
long count = 0;
int nid;
- for_each_node_mask(nid, lru->active_nodes) {
+ for_each_node_mask(nid, *nodes_to_count) {
struct list_lru_node *nlru = &lru->node[nid];
spin_lock(&nlru->lock);
@@ -70,7 +70,7 @@ list_lru_count(struct list_lru *lru)
return count;
}
-EXPORT_SYMBOL_GPL(list_lru_count);
+EXPORT_SYMBOL_GPL(list_lru_count_nodemask);
static unsigned long
list_lru_walk_node(
@@ -119,16 +119,17 @@ restart:
}
unsigned long
-list_lru_walk(
+list_lru_walk_nodemask(
struct list_lru *lru,
list_lru_walk_cb isolate,
void *cb_arg,
- unsigned long nr_to_walk)
+ unsigned long nr_to_walk,
+ nodemask_t *nodes_to_walk)
{
long isolated = 0;
int nid;
- for_each_node_mask(nid, lru->active_nodes) {
+ for_each_node_mask(nid, *nodes_to_walk) {
isolated += list_lru_walk_node(lru, nid, isolate,
cb_arg, &nr_to_walk);
if (nr_to_walk <= 0)
@@ -136,7 +137,7 @@ list_lru_walk(
}
return isolated;
}
-EXPORT_SYMBOL_GPL(list_lru_walk);
+EXPORT_SYMBOL_GPL(list_lru_walk_nodemask);
static unsigned long
list_lru_dispose_all_node(
--
1.8.1.4
--
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^ permalink raw reply related [flat|nested] 151+ messages in thread[parent not found: <1368382432-25462-13-git-send-email-glommer-GEFAQzZX7r8dnm+yROfE0A@public.gmane.org>]
* Re: [PATCH v6 12/31] fs: convert inode and dentry shrinking to be node aware
2013-05-12 18:13 ` Glauber Costa
@ 2013-05-14 9:52 ` Dave Chinner
-1 siblings, 0 replies; 151+ messages in thread
From: Dave Chinner @ 2013-05-14 9:52 UTC (permalink / raw)
To: Glauber Costa
Cc: linux-mm-Bw31MaZKKs3YtjvyW6yDsg, cgroups-u79uwXL29TY76Z2rM5mHXA,
Andrew Morton, Greg Thelen,
kamezawa.hiroyu-+CUm20s59erQFUHtdCDX3A, Michal Hocko,
Johannes Weiner, linux-fsdevel-u79uwXL29TY76Z2rM5mHXA,
Dave Chinner, Glauber Costa
On Sun, May 12, 2013 at 10:13:33PM +0400, Glauber Costa wrote:
> From: Dave Chinner <dchinner-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>
>
> Now that the shrinker is passing a nodemask in the scan control
> structure, we can pass this to the the generic LRU list code to
> isolate reclaim to the lists on matching nodes.
>
> This requires a small amount of refactoring of the LRU list API,
> which might be best split out into a separate patch.
>
> Signed-off-by: Dave Chinner <dchinner-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>
> Signed-off-by: Glauber Costa <glommer-bzQdu9zFT3WakBO8gow8eQ@public.gmane.org>
> Acked-by: Mel Gorman <mgorman-l3A5Bk7waGM@public.gmane.org>
What I see at this point is that the superblock shrinkers appear to
be way too agressive. As soon as memory pressure hits, the slab
caches are getting emptied down to almost nothing. I'm testing on a
4 node fake-numa system here, so I initially suspected what is
happening is that the amount of reclaim has just been multiplied by
4.
Peak performance is good, it's just that there is no stable steady
state - the caches are either filling at maximum rate, or being
emptied at maximum rate - and that implies that the shrinkers are
doing more work than they need to.
I think this is the point at what we need to ensure that the balance
between the dentry/inode caches and the page cache is balanced, so
I'm going to see what happens when I tweak a few numbers. e.g. see
what effect tweaking shrink.seeks has on the rate of change of the
cache sizes.....
Changing the seek count doesn't change the fact that it's
fundamentally unstable. More investigation needed. Trace points.
kswapd0-632 mm_shrink_slab_start: objects to shrink 945211
gfp_flags GFP_KERNEL pgs_scanned 32 lru_pgs 7046
cache items 600456 delta 1363 total_scan 300228
Bingo. We've got windup!
objects to shrink = shrinker->nr_in_batch
= 945211
= large amount of deferred work
cache items = max_pass
= current cache size
= 600456
total_scan = 300228
= (cache items) / 2.
delta = 1363
And this code:
/*
* We need to avoid excessive windup on filesystem shrinkers
* due to large numbers of GFP_NOFS allocations causing the
* shrinkers to return -1 all the time. This results in a large
* nr being built up so when a shrink that can do some work
* comes along it empties the entire cache due to nr >>>
* max_pass. This is bad for sustaining a working set in
* memory.
*
* Hence only allow the shrinker to scan the entire cache when
* a large delta change is calculated directly.
*/
if (delta < max_pass / 4)
total_scan = min(total_scan, max_pass / 2);
Has obviously triggered.
So, it would seem to me that we have a relatively small amount of
incremental memory pressure, but an awful lot of deferred work. When
I see this:
kswapd0-632 1210443.469309: mm_shrink_slab_start: cache items 600456 delta 1363 total_scan 300228
kswapd3-635 1210443.510311: mm_shrink_slab_start: cache items 514885 delta 1250 total_scan 101025
kswapd1-633 1210443.517440: mm_shrink_slab_start: cache items 613824 delta 1357 total_scan 97727
kswapd2-634 1210443.527026: mm_shrink_slab_start: cache items 568610 delta 1331 total_scan 259185
kswapd3-635 1210443.573165: mm_shrink_slab_start: cache items 486408 delta 1277 total_scan 243204
kswapd1-633 1210443.697012: mm_shrink_slab_start: cache items 550827 delta 1224 total_scan 82231
in the space of 230ms, I can see why the caches are getting
completely emptied. kswapds are making multiple, large scale scan
passes on the caches. Looks like our problem is an impedence
mismatch: global windup counter, per-node cache scan calculations.
So, that's the mess we really need to cleaning up before going much
further with this patchset. We need stable behaviour from the
shrinkers - I'll look into this a bit deeper tomorrow.
Cheers,
Dave.
--
Dave Chinner
david-FqsqvQoI3Ljby3iVrkZq2A@public.gmane.org
^ permalink raw reply [flat|nested] 151+ messages in thread* Re: [PATCH v6 12/31] fs: convert inode and dentry shrinking to be node aware
@ 2013-05-14 9:52 ` Dave Chinner
0 siblings, 0 replies; 151+ messages in thread
From: Dave Chinner @ 2013-05-14 9:52 UTC (permalink / raw)
To: Glauber Costa
Cc: linux-mm, cgroups, Andrew Morton, Greg Thelen, kamezawa.hiroyu,
Michal Hocko, Johannes Weiner, linux-fsdevel, Dave Chinner,
Glauber Costa
On Sun, May 12, 2013 at 10:13:33PM +0400, Glauber Costa wrote:
> From: Dave Chinner <dchinner@redhat.com>
>
> Now that the shrinker is passing a nodemask in the scan control
> structure, we can pass this to the the generic LRU list code to
> isolate reclaim to the lists on matching nodes.
>
> This requires a small amount of refactoring of the LRU list API,
> which might be best split out into a separate patch.
>
> Signed-off-by: Dave Chinner <dchinner@redhat.com>
> Signed-off-by: Glauber Costa <glommer@parallels.com>
> Acked-by: Mel Gorman <mgorman@suse.de>
What I see at this point is that the superblock shrinkers appear to
be way too agressive. As soon as memory pressure hits, the slab
caches are getting emptied down to almost nothing. I'm testing on a
4 node fake-numa system here, so I initially suspected what is
happening is that the amount of reclaim has just been multiplied by
4.
Peak performance is good, it's just that there is no stable steady
state - the caches are either filling at maximum rate, or being
emptied at maximum rate - and that implies that the shrinkers are
doing more work than they need to.
I think this is the point at what we need to ensure that the balance
between the dentry/inode caches and the page cache is balanced, so
I'm going to see what happens when I tweak a few numbers. e.g. see
what effect tweaking shrink.seeks has on the rate of change of the
cache sizes.....
Changing the seek count doesn't change the fact that it's
fundamentally unstable. More investigation needed. Trace points.
kswapd0-632 mm_shrink_slab_start: objects to shrink 945211
gfp_flags GFP_KERNEL pgs_scanned 32 lru_pgs 7046
cache items 600456 delta 1363 total_scan 300228
Bingo. We've got windup!
objects to shrink = shrinker->nr_in_batch
= 945211
= large amount of deferred work
cache items = max_pass
= current cache size
= 600456
total_scan = 300228
= (cache items) / 2.
delta = 1363
And this code:
/*
* We need to avoid excessive windup on filesystem shrinkers
* due to large numbers of GFP_NOFS allocations causing the
* shrinkers to return -1 all the time. This results in a large
* nr being built up so when a shrink that can do some work
* comes along it empties the entire cache due to nr >>>
* max_pass. This is bad for sustaining a working set in
* memory.
*
* Hence only allow the shrinker to scan the entire cache when
* a large delta change is calculated directly.
*/
if (delta < max_pass / 4)
total_scan = min(total_scan, max_pass / 2);
Has obviously triggered.
So, it would seem to me that we have a relatively small amount of
incremental memory pressure, but an awful lot of deferred work. When
I see this:
kswapd0-632 1210443.469309: mm_shrink_slab_start: cache items 600456 delta 1363 total_scan 300228
kswapd3-635 1210443.510311: mm_shrink_slab_start: cache items 514885 delta 1250 total_scan 101025
kswapd1-633 1210443.517440: mm_shrink_slab_start: cache items 613824 delta 1357 total_scan 97727
kswapd2-634 1210443.527026: mm_shrink_slab_start: cache items 568610 delta 1331 total_scan 259185
kswapd3-635 1210443.573165: mm_shrink_slab_start: cache items 486408 delta 1277 total_scan 243204
kswapd1-633 1210443.697012: mm_shrink_slab_start: cache items 550827 delta 1224 total_scan 82231
in the space of 230ms, I can see why the caches are getting
completely emptied. kswapds are making multiple, large scale scan
passes on the caches. Looks like our problem is an impedence
mismatch: global windup counter, per-node cache scan calculations.
So, that's the mess we really need to cleaning up before going much
further with this patchset. We need stable behaviour from the
shrinkers - I'll look into this a bit deeper tomorrow.
Cheers,
Dave.
--
Dave Chinner
david@fromorbit.com
--
To unsubscribe, send a message with 'unsubscribe linux-mm' in
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^ permalink raw reply [flat|nested] 151+ messages in thread* Re: [PATCH v6 12/31] fs: convert inode and dentry shrinking to be node aware
2013-05-14 9:52 ` Dave Chinner
(?)
@ 2013-05-15 15:27 ` Glauber Costa
-1 siblings, 0 replies; 151+ messages in thread
From: Glauber Costa @ 2013-05-15 15:27 UTC (permalink / raw)
To: Dave Chinner
Cc: Glauber Costa, linux-mm-Bw31MaZKKs3YtjvyW6yDsg,
cgroups-u79uwXL29TY76Z2rM5mHXA, Andrew Morton, Greg Thelen,
kamezawa.hiroyu-+CUm20s59erQFUHtdCDX3A, Michal Hocko,
Johannes Weiner, linux-fsdevel-u79uwXL29TY76Z2rM5mHXA,
Dave Chinner
On 05/14/2013 01:52 PM, Dave Chinner wrote:
> kswapd0-632 1210443.469309: mm_shrink_slab_start: cache items 600456 delta 1363 total_scan 300228
> kswapd3-635 1210443.510311: mm_shrink_slab_start: cache items 514885 delta 1250 total_scan 101025
> kswapd1-633 1210443.517440: mm_shrink_slab_start: cache items 613824 delta 1357 total_scan 97727
> kswapd2-634 1210443.527026: mm_shrink_slab_start: cache items 568610 delta 1331 total_scan 259185
> kswapd3-635 1210443.573165: mm_shrink_slab_start: cache items 486408 delta 1277 total_scan 243204
> kswapd1-633 1210443.697012: mm_shrink_slab_start: cache items 550827 delta 1224 total_scan 82231
>
> in the space of 230ms, I can see why the caches are getting
> completely emptied. kswapds are making multiple, large scale scan
> passes on the caches. Looks like our problem is an impedence
> mismatch: global windup counter, per-node cache scan calculations.
>
> So, that's the mess we really need to cleaning up before going much
> further with this patchset. We need stable behaviour from the
> shrinkers - I'll look into this a bit deeper tomorrow.
That doesn't totally make sense to me.
Both our scan and count functions will be per-node now. This means we
will always try to keep ourselves within reasonable maximums on a
per-node basis as well.
^ permalink raw reply [flat|nested] 151+ messages in thread
* Re: [PATCH v6 12/31] fs: convert inode and dentry shrinking to be node aware
@ 2013-05-15 15:27 ` Glauber Costa
0 siblings, 0 replies; 151+ messages in thread
From: Glauber Costa @ 2013-05-15 15:27 UTC (permalink / raw)
To: Dave Chinner
Cc: Glauber Costa, linux-mm-Bw31MaZKKs3YtjvyW6yDsg,
cgroups-u79uwXL29TY76Z2rM5mHXA, Andrew Morton, Greg Thelen,
kamezawa.hiroyu-+CUm20s59erQFUHtdCDX3A, Michal Hocko,
Johannes Weiner, linux-fsdevel-u79uwXL29TY76Z2rM5mHXA,
Dave Chinner
On 05/14/2013 01:52 PM, Dave Chinner wrote:
> kswapd0-632 1210443.469309: mm_shrink_slab_start: cache items 600456 delta 1363 total_scan 300228
> kswapd3-635 1210443.510311: mm_shrink_slab_start: cache items 514885 delta 1250 total_scan 101025
> kswapd1-633 1210443.517440: mm_shrink_slab_start: cache items 613824 delta 1357 total_scan 97727
> kswapd2-634 1210443.527026: mm_shrink_slab_start: cache items 568610 delta 1331 total_scan 259185
> kswapd3-635 1210443.573165: mm_shrink_slab_start: cache items 486408 delta 1277 total_scan 243204
> kswapd1-633 1210443.697012: mm_shrink_slab_start: cache items 550827 delta 1224 total_scan 82231
>
> in the space of 230ms, I can see why the caches are getting
> completely emptied. kswapds are making multiple, large scale scan
> passes on the caches. Looks like our problem is an impedence
> mismatch: global windup counter, per-node cache scan calculations.
>
> So, that's the mess we really need to cleaning up before going much
> further with this patchset. We need stable behaviour from the
> shrinkers - I'll look into this a bit deeper tomorrow.
That doesn't totally make sense to me.
Both our scan and count functions will be per-node now. This means we
will always try to keep ourselves within reasonable maximums on a
per-node basis as well.
^ permalink raw reply [flat|nested] 151+ messages in thread
* Re: [PATCH v6 12/31] fs: convert inode and dentry shrinking to be node aware
@ 2013-05-15 15:27 ` Glauber Costa
0 siblings, 0 replies; 151+ messages in thread
From: Glauber Costa @ 2013-05-15 15:27 UTC (permalink / raw)
To: Dave Chinner
Cc: Glauber Costa, linux-mm, cgroups, Andrew Morton, Greg Thelen,
kamezawa.hiroyu, Michal Hocko, Johannes Weiner, linux-fsdevel,
Dave Chinner
On 05/14/2013 01:52 PM, Dave Chinner wrote:
> kswapd0-632 1210443.469309: mm_shrink_slab_start: cache items 600456 delta 1363 total_scan 300228
> kswapd3-635 1210443.510311: mm_shrink_slab_start: cache items 514885 delta 1250 total_scan 101025
> kswapd1-633 1210443.517440: mm_shrink_slab_start: cache items 613824 delta 1357 total_scan 97727
> kswapd2-634 1210443.527026: mm_shrink_slab_start: cache items 568610 delta 1331 total_scan 259185
> kswapd3-635 1210443.573165: mm_shrink_slab_start: cache items 486408 delta 1277 total_scan 243204
> kswapd1-633 1210443.697012: mm_shrink_slab_start: cache items 550827 delta 1224 total_scan 82231
>
> in the space of 230ms, I can see why the caches are getting
> completely emptied. kswapds are making multiple, large scale scan
> passes on the caches. Looks like our problem is an impedence
> mismatch: global windup counter, per-node cache scan calculations.
>
> So, that's the mess we really need to cleaning up before going much
> further with this patchset. We need stable behaviour from the
> shrinkers - I'll look into this a bit deeper tomorrow.
That doesn't totally make sense to me.
Both our scan and count functions will be per-node now. This means we
will always try to keep ourselves within reasonable maximums on a
per-node basis as well.
--
To unsubscribe, send a message with 'unsubscribe linux-mm' in
the body to majordomo@kvack.org. For more info on Linux MM,
see: http://www.linux-mm.org/ .
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^ permalink raw reply [flat|nested] 151+ messages in thread
* Re: [PATCH v6 12/31] fs: convert inode and dentry shrinking to be node aware
2013-05-15 15:27 ` Glauber Costa
(?)
(?)
@ 2013-05-16 0:02 ` Dave Chinner
2013-05-16 8:03 ` Glauber Costa
2013-05-16 19:14 ` Glauber Costa
-1 siblings, 2 replies; 151+ messages in thread
From: Dave Chinner @ 2013-05-16 0:02 UTC (permalink / raw)
To: Glauber Costa
Cc: Glauber Costa, linux-mm, cgroups, Andrew Morton, Greg Thelen,
kamezawa.hiroyu, Michal Hocko, Johannes Weiner, linux-fsdevel,
Dave Chinner
On Wed, May 15, 2013 at 07:27:26PM +0400, Glauber Costa wrote:
> On 05/14/2013 01:52 PM, Dave Chinner wrote:
> > kswapd0-632 1210443.469309: mm_shrink_slab_start: cache items 600456 delta 1363 total_scan 300228
> > kswapd3-635 1210443.510311: mm_shrink_slab_start: cache items 514885 delta 1250 total_scan 101025
> > kswapd1-633 1210443.517440: mm_shrink_slab_start: cache items 613824 delta 1357 total_scan 97727
> > kswapd2-634 1210443.527026: mm_shrink_slab_start: cache items 568610 delta 1331 total_scan 259185
> > kswapd3-635 1210443.573165: mm_shrink_slab_start: cache items 486408 delta 1277 total_scan 243204
> > kswapd1-633 1210443.697012: mm_shrink_slab_start: cache items 550827 delta 1224 total_scan 82231
> >
> > in the space of 230ms, I can see why the caches are getting
> > completely emptied. kswapds are making multiple, large scale scan
> > passes on the caches. Looks like our problem is an impedence
> > mismatch: global windup counter, per-node cache scan calculations.
> >
> > So, that's the mess we really need to cleaning up before going much
> > further with this patchset. We need stable behaviour from the
> > shrinkers - I'll look into this a bit deeper tomorrow.
>
> That doesn't totally make sense to me.
>
> Both our scan and count functions will be per-node now. This means we
> will always try to keep ourselves within reasonable maximums on a
> per-node basis as well.
Right, but if we have a bunch of GFP_NOFS reclaims on multiple nodes
at the same time, we get:
max_pass = shr->count_objects;
nr = shr->nr_in_batch
shr->nr_in_batch = 0
/* total_scan has new delta added */
/* nothing scanned */
shr->nr_in_batch += total_scan;
And then the next node does the same, and so on.
What I cut from the above output was the shr->nr_in_batch values.
They were:
kswapd1-633 [001] 1210443.500045: objects to shrink 4077
gfp_flags GFP_KERNEL pgs_scanned 32 lru_pgs 7096 cache
items 623079 delta 1404 total_scan 5481
kswapd1-633 [001] 1210443.504315: objects to shrink 15138
gfp_flags GFP_KERNEL pgs_scanned 32 lru_pgs 7224 cache
items 620936 delta 1375 total_scan 16513
kswapd3-635 [007] 1210443.510311: objects to shrink 99775
gfp_flags GFP_KERNEL pgs_scanned 32 lru_pgs 6587 cache
items 514885 delta 1250 total_scan 101025
kswapd1-633 [001] 1210443.517440: objects to shrink 96370
gfp_flags GFP_KERNEL pgs_scanned 32 lru_pgs 7236 cache
items 613824 delta 1357 total_scan 97727
kswapd2-634 [006] 1210443.527026: objects to shrink 257854
gfp_flags GFP_KERNEL pgs_scanned 32 lru_pgs 6831 cache
items 568610 delta 1331 total_scan 259185
kswapd3-635 [007] 1210443.573165: objects to shrink 1034342
gfp_flags GFP_KERNEL pgs_scanned 32 lru_pgs 6089 cache
items 486408 delta 1277 total_scan 243204
So you can see that the number of objects being deferred is driving
the total_scan count completely in these cases.
This is over a period of 70ms - shr->nr_in_batch has gone from
roughly zero to 1034342 because of deferred work. Between these
traces are hundreds of GFP_NOFS reclaims from all 8 cpus (i.e.
direct reclaim, every 300-400us on *each* CPU), each adding ~1200 to
shr->nr_in_batch, and the only thing able to reclaim memory is
kswapd as it does GFP_KERNEL context reclaim.
IOWs, each kswapd is taking the global windup and applying it to
each per-node list, when in fact the windup is not distributed that
way. The trace leading up to this kswapd scan:
kswapd1-633 [001] 1210443.517440: objects to shrink 96370
gfp_flags GFP_KERNEL pgs_scanned 32 lru_pgs 7236 cache
items 613824 delta 1357 total_scan 97727
Shows that most of the deferred work has come from CPUs 2, 3, 4 and
a little from CPU 5. The cpu->node map shows that only CPU 5 is on
node 1 (cpus 1 and 5 are on node 1), so this means that less than a
quarter of the work that this node 1 shrinker is being asked to do
was deferred from node 1. Most of it was deferred from nodes 0, 2
and 3, and so this work the shrinker is doing is doing nothing to
relieve the memory pressure on those nodes. So direct reclaim on
those nodes continues to wind up the nr_in_batch count.
And look at where the per-node cache count and windup is getting to
at times in this process:
fs_mark-5561 [002] 1210443.555528: objects to shrink 2914436
gfp_flags GFP_NOFS|GFP_NOWARN|GFP_NORETRY|GFP_COMP|GFP_RECLAIMABLE|GFP_NOTRACK
pgs_scanned 32 lru_pgs 26591
cache items 2085764 delta 1254 total_scan 1042882
What we see here is a node with more than 2 million filesystem items cached on
it. The other nodes are around 500,000 at this point, indicating
that we definitely have a per-node reclaim imbalance....
IOWs, shr->nr_in_batch can grow much larger than any single node LRU
list, and the deffered count is only limited to (2 * max_pass).
Hence if the same node is the one that keeps stealing the global
shr->nr_in_batch calculation, it will always be a number related to
the size of the cache on that node. All the other nodes will simply
keep adding their delta counts to it.
Hence if you've got a node with less cache in it than others, and
kswapd comes along, it will see a gigantic amount of deferred work
in nr_in_batch, and then we end up removing a large amount of the
cache on that node, even though it hasn't had a significant amount
of pressure. And the node that has pressure continues to wind up
nr_in_batch until it's the one that gets hit by a kswapd run with
that wound up nr_in_batch....
Cheers,
Dave.
--
Dave Chinner
david@fromorbit.com
--
To unsubscribe, send a message with 'unsubscribe linux-mm' in
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^ permalink raw reply [flat|nested] 151+ messages in thread
* Re: [PATCH v6 12/31] fs: convert inode and dentry shrinking to be node aware
2013-05-16 0:02 ` Dave Chinner
2013-05-16 8:03 ` Glauber Costa
@ 2013-05-16 8:03 ` Glauber Costa
1 sibling, 0 replies; 151+ messages in thread
From: Glauber Costa @ 2013-05-16 8:03 UTC (permalink / raw)
To: Dave Chinner
Cc: Glauber Costa, linux-mm-Bw31MaZKKs3YtjvyW6yDsg,
cgroups-u79uwXL29TY76Z2rM5mHXA, Andrew Morton, Greg Thelen,
kamezawa.hiroyu-+CUm20s59erQFUHtdCDX3A, Michal Hocko,
Johannes Weiner, linux-fsdevel-u79uwXL29TY76Z2rM5mHXA,
Dave Chinner
On 05/16/2013 04:02 AM, Dave Chinner wrote:
> On Wed, May 15, 2013 at 07:27:26PM +0400, Glauber Costa wrote:
>> On 05/14/2013 01:52 PM, Dave Chinner wrote:
>>> kswapd0-632 1210443.469309: mm_shrink_slab_start: cache items 600456 delta 1363 total_scan 300228
>>> kswapd3-635 1210443.510311: mm_shrink_slab_start: cache items 514885 delta 1250 total_scan 101025
>>> kswapd1-633 1210443.517440: mm_shrink_slab_start: cache items 613824 delta 1357 total_scan 97727
>>> kswapd2-634 1210443.527026: mm_shrink_slab_start: cache items 568610 delta 1331 total_scan 259185
>>> kswapd3-635 1210443.573165: mm_shrink_slab_start: cache items 486408 delta 1277 total_scan 243204
>>> kswapd1-633 1210443.697012: mm_shrink_slab_start: cache items 550827 delta 1224 total_scan 82231
>>>
>>> in the space of 230ms, I can see why the caches are getting
>>> completely emptied. kswapds are making multiple, large scale scan
>>> passes on the caches. Looks like our problem is an impedence
>>> mismatch: global windup counter, per-node cache scan calculations.
>>>
>>> So, that's the mess we really need to cleaning up before going much
>>> further with this patchset. We need stable behaviour from the
>>> shrinkers - I'll look into this a bit deeper tomorrow.
>>
>> That doesn't totally make sense to me.
>>
>> Both our scan and count functions will be per-node now. This means we
>> will always try to keep ourselves within reasonable maximums on a
>> per-node basis as well.
>
> Right, but if we have a bunch of GFP_NOFS reclaims on multiple nodes
> at the same time, we get:
>
> max_pass = shr->count_objects;
> nr = shr->nr_in_batch
> shr->nr_in_batch = 0
> /* total_scan has new delta added */
> /* nothing scanned */
> shr->nr_in_batch += total_scan;
>
> And then the next node does the same, and so on.
>
> What I cut from the above output was the shr->nr_in_batch values.
> They were:
>
> kswapd1-633 [001] 1210443.500045: objects to shrink 4077
> gfp_flags GFP_KERNEL pgs_scanned 32 lru_pgs 7096 cache
> items 623079 delta 1404 total_scan 5481
> kswapd1-633 [001] 1210443.504315: objects to shrink 15138
> gfp_flags GFP_KERNEL pgs_scanned 32 lru_pgs 7224 cache
> items 620936 delta 1375 total_scan 16513
> kswapd3-635 [007] 1210443.510311: objects to shrink 99775
> gfp_flags GFP_KERNEL pgs_scanned 32 lru_pgs 6587 cache
> items 514885 delta 1250 total_scan 101025
> kswapd1-633 [001] 1210443.517440: objects to shrink 96370
> gfp_flags GFP_KERNEL pgs_scanned 32 lru_pgs 7236 cache
> items 613824 delta 1357 total_scan 97727
> kswapd2-634 [006] 1210443.527026: objects to shrink 257854
> gfp_flags GFP_KERNEL pgs_scanned 32 lru_pgs 6831 cache
> items 568610 delta 1331 total_scan 259185
> kswapd3-635 [007] 1210443.573165: objects to shrink 1034342
> gfp_flags GFP_KERNEL pgs_scanned 32 lru_pgs 6089 cache
> items 486408 delta 1277 total_scan 243204
>
> So you can see that the number of objects being deferred is driving
> the total_scan count completely in these cases.
>
> This is over a period of 70ms - shr->nr_in_batch has gone from
> roughly zero to 1034342 because of deferred work. Between these
> traces are hundreds of GFP_NOFS reclaims from all 8 cpus (i.e.
> direct reclaim, every 300-400us on *each* CPU), each adding ~1200 to
> shr->nr_in_batch, and the only thing able to reclaim memory is
> kswapd as it does GFP_KERNEL context reclaim.
>
> IOWs, each kswapd is taking the global windup and applying it to
> each per-node list, when in fact the windup is not distributed that
> way. The trace leading up to this kswapd scan:
>
> kswapd1-633 [001] 1210443.517440: objects to shrink 96370
> gfp_flags GFP_KERNEL pgs_scanned 32 lru_pgs 7236 cache
> items 613824 delta 1357 total_scan 97727
>
> Shows that most of the deferred work has come from CPUs 2, 3, 4 and
> a little from CPU 5. The cpu->node map shows that only CPU 5 is on
> node 1 (cpus 1 and 5 are on node 1), so this means that less than a
> quarter of the work that this node 1 shrinker is being asked to do
> was deferred from node 1. Most of it was deferred from nodes 0, 2
> and 3, and so this work the shrinker is doing is doing nothing to
> relieve the memory pressure on those nodes. So direct reclaim on
> those nodes continues to wind up the nr_in_batch count.
>
> And look at where the per-node cache count and windup is getting to
> at times in this process:
>
> fs_mark-5561 [002] 1210443.555528: objects to shrink 2914436
> gfp_flags GFP_NOFS|GFP_NOWARN|GFP_NORETRY|GFP_COMP|GFP_RECLAIMABLE|GFP_NOTRACK
> pgs_scanned 32 lru_pgs 26591
> cache items 2085764 delta 1254 total_scan 1042882
>
> What we see here is a node with more than 2 million filesystem items cached on
> it. The other nodes are around 500,000 at this point, indicating
> that we definitely have a per-node reclaim imbalance....
>
> IOWs, shr->nr_in_batch can grow much larger than any single node LRU
> list, and the deffered count is only limited to (2 * max_pass).
> Hence if the same node is the one that keeps stealing the global
> shr->nr_in_batch calculation, it will always be a number related to
> the size of the cache on that node. All the other nodes will simply
> keep adding their delta counts to it.
>
> Hence if you've got a node with less cache in it than others, and
> kswapd comes along, it will see a gigantic amount of deferred work
> in nr_in_batch, and then we end up removing a large amount of the
> cache on that node, even though it hasn't had a significant amount
> of pressure. And the node that has pressure continues to wind up
> nr_in_batch until it's the one that gets hit by a kswapd run with
> that wound up nr_in_batch....
>
That makes sense now, thanks. It doesn't seem, however, that any deep
black magic is required to fix this here.
Any reason why proportional scanning wouldn't work ?
If we have a very large nr_in_batch, and many nodes to scan, we can try
dividing them among present nodes in the proportion of existing objects
in the cache.
Or maybe even better, we can make deferring work node aware, so when you
defer, you don't defer to a global pool, but rather to a node copy.
^ permalink raw reply [flat|nested] 151+ messages in thread
* Re: [PATCH v6 12/31] fs: convert inode and dentry shrinking to be node aware
@ 2013-05-16 8:03 ` Glauber Costa
0 siblings, 0 replies; 151+ messages in thread
From: Glauber Costa @ 2013-05-16 8:03 UTC (permalink / raw)
To: Dave Chinner
Cc: Glauber Costa, linux-mm-Bw31MaZKKs3YtjvyW6yDsg,
cgroups-u79uwXL29TY76Z2rM5mHXA, Andrew Morton, Greg Thelen,
kamezawa.hiroyu-+CUm20s59erQFUHtdCDX3A, Michal Hocko,
Johannes Weiner, linux-fsdevel-u79uwXL29TY76Z2rM5mHXA,
Dave Chinner
On 05/16/2013 04:02 AM, Dave Chinner wrote:
> On Wed, May 15, 2013 at 07:27:26PM +0400, Glauber Costa wrote:
>> On 05/14/2013 01:52 PM, Dave Chinner wrote:
>>> kswapd0-632 1210443.469309: mm_shrink_slab_start: cache items 600456 delta 1363 total_scan 300228
>>> kswapd3-635 1210443.510311: mm_shrink_slab_start: cache items 514885 delta 1250 total_scan 101025
>>> kswapd1-633 1210443.517440: mm_shrink_slab_start: cache items 613824 delta 1357 total_scan 97727
>>> kswapd2-634 1210443.527026: mm_shrink_slab_start: cache items 568610 delta 1331 total_scan 259185
>>> kswapd3-635 1210443.573165: mm_shrink_slab_start: cache items 486408 delta 1277 total_scan 243204
>>> kswapd1-633 1210443.697012: mm_shrink_slab_start: cache items 550827 delta 1224 total_scan 82231
>>>
>>> in the space of 230ms, I can see why the caches are getting
>>> completely emptied. kswapds are making multiple, large scale scan
>>> passes on the caches. Looks like our problem is an impedence
>>> mismatch: global windup counter, per-node cache scan calculations.
>>>
>>> So, that's the mess we really need to cleaning up before going much
>>> further with this patchset. We need stable behaviour from the
>>> shrinkers - I'll look into this a bit deeper tomorrow.
>>
>> That doesn't totally make sense to me.
>>
>> Both our scan and count functions will be per-node now. This means we
>> will always try to keep ourselves within reasonable maximums on a
>> per-node basis as well.
>
> Right, but if we have a bunch of GFP_NOFS reclaims on multiple nodes
> at the same time, we get:
>
> max_pass = shr->count_objects;
> nr = shr->nr_in_batch
> shr->nr_in_batch = 0
> /* total_scan has new delta added */
> /* nothing scanned */
> shr->nr_in_batch += total_scan;
>
> And then the next node does the same, and so on.
>
> What I cut from the above output was the shr->nr_in_batch values.
> They were:
>
> kswapd1-633 [001] 1210443.500045: objects to shrink 4077
> gfp_flags GFP_KERNEL pgs_scanned 32 lru_pgs 7096 cache
> items 623079 delta 1404 total_scan 5481
> kswapd1-633 [001] 1210443.504315: objects to shrink 15138
> gfp_flags GFP_KERNEL pgs_scanned 32 lru_pgs 7224 cache
> items 620936 delta 1375 total_scan 16513
> kswapd3-635 [007] 1210443.510311: objects to shrink 99775
> gfp_flags GFP_KERNEL pgs_scanned 32 lru_pgs 6587 cache
> items 514885 delta 1250 total_scan 101025
> kswapd1-633 [001] 1210443.517440: objects to shrink 96370
> gfp_flags GFP_KERNEL pgs_scanned 32 lru_pgs 7236 cache
> items 613824 delta 1357 total_scan 97727
> kswapd2-634 [006] 1210443.527026: objects to shrink 257854
> gfp_flags GFP_KERNEL pgs_scanned 32 lru_pgs 6831 cache
> items 568610 delta 1331 total_scan 259185
> kswapd3-635 [007] 1210443.573165: objects to shrink 1034342
> gfp_flags GFP_KERNEL pgs_scanned 32 lru_pgs 6089 cache
> items 486408 delta 1277 total_scan 243204
>
> So you can see that the number of objects being deferred is driving
> the total_scan count completely in these cases.
>
> This is over a period of 70ms - shr->nr_in_batch has gone from
> roughly zero to 1034342 because of deferred work. Between these
> traces are hundreds of GFP_NOFS reclaims from all 8 cpus (i.e.
> direct reclaim, every 300-400us on *each* CPU), each adding ~1200 to
> shr->nr_in_batch, and the only thing able to reclaim memory is
> kswapd as it does GFP_KERNEL context reclaim.
>
> IOWs, each kswapd is taking the global windup and applying it to
> each per-node list, when in fact the windup is not distributed that
> way. The trace leading up to this kswapd scan:
>
> kswapd1-633 [001] 1210443.517440: objects to shrink 96370
> gfp_flags GFP_KERNEL pgs_scanned 32 lru_pgs 7236 cache
> items 613824 delta 1357 total_scan 97727
>
> Shows that most of the deferred work has come from CPUs 2, 3, 4 and
> a little from CPU 5. The cpu->node map shows that only CPU 5 is on
> node 1 (cpus 1 and 5 are on node 1), so this means that less than a
> quarter of the work that this node 1 shrinker is being asked to do
> was deferred from node 1. Most of it was deferred from nodes 0, 2
> and 3, and so this work the shrinker is doing is doing nothing to
> relieve the memory pressure on those nodes. So direct reclaim on
> those nodes continues to wind up the nr_in_batch count.
>
> And look at where the per-node cache count and windup is getting to
> at times in this process:
>
> fs_mark-5561 [002] 1210443.555528: objects to shrink 2914436
> gfp_flags GFP_NOFS|GFP_NOWARN|GFP_NORETRY|GFP_COMP|GFP_RECLAIMABLE|GFP_NOTRACK
> pgs_scanned 32 lru_pgs 26591
> cache items 2085764 delta 1254 total_scan 1042882
>
> What we see here is a node with more than 2 million filesystem items cached on
> it. The other nodes are around 500,000 at this point, indicating
> that we definitely have a per-node reclaim imbalance....
>
> IOWs, shr->nr_in_batch can grow much larger than any single node LRU
> list, and the deffered count is only limited to (2 * max_pass).
> Hence if the same node is the one that keeps stealing the global
> shr->nr_in_batch calculation, it will always be a number related to
> the size of the cache on that node. All the other nodes will simply
> keep adding their delta counts to it.
>
> Hence if you've got a node with less cache in it than others, and
> kswapd comes along, it will see a gigantic amount of deferred work
> in nr_in_batch, and then we end up removing a large amount of the
> cache on that node, even though it hasn't had a significant amount
> of pressure. And the node that has pressure continues to wind up
> nr_in_batch until it's the one that gets hit by a kswapd run with
> that wound up nr_in_batch....
>
That makes sense now, thanks. It doesn't seem, however, that any deep
black magic is required to fix this here.
Any reason why proportional scanning wouldn't work ?
If we have a very large nr_in_batch, and many nodes to scan, we can try
dividing them among present nodes in the proportion of existing objects
in the cache.
Or maybe even better, we can make deferring work node aware, so when you
defer, you don't defer to a global pool, but rather to a node copy.
^ permalink raw reply [flat|nested] 151+ messages in thread
* Re: [PATCH v6 12/31] fs: convert inode and dentry shrinking to be node aware
@ 2013-05-16 8:03 ` Glauber Costa
0 siblings, 0 replies; 151+ messages in thread
From: Glauber Costa @ 2013-05-16 8:03 UTC (permalink / raw)
To: Dave Chinner
Cc: Glauber Costa, linux-mm, cgroups, Andrew Morton, Greg Thelen,
kamezawa.hiroyu, Michal Hocko, Johannes Weiner, linux-fsdevel,
Dave Chinner
On 05/16/2013 04:02 AM, Dave Chinner wrote:
> On Wed, May 15, 2013 at 07:27:26PM +0400, Glauber Costa wrote:
>> On 05/14/2013 01:52 PM, Dave Chinner wrote:
>>> kswapd0-632 1210443.469309: mm_shrink_slab_start: cache items 600456 delta 1363 total_scan 300228
>>> kswapd3-635 1210443.510311: mm_shrink_slab_start: cache items 514885 delta 1250 total_scan 101025
>>> kswapd1-633 1210443.517440: mm_shrink_slab_start: cache items 613824 delta 1357 total_scan 97727
>>> kswapd2-634 1210443.527026: mm_shrink_slab_start: cache items 568610 delta 1331 total_scan 259185
>>> kswapd3-635 1210443.573165: mm_shrink_slab_start: cache items 486408 delta 1277 total_scan 243204
>>> kswapd1-633 1210443.697012: mm_shrink_slab_start: cache items 550827 delta 1224 total_scan 82231
>>>
>>> in the space of 230ms, I can see why the caches are getting
>>> completely emptied. kswapds are making multiple, large scale scan
>>> passes on the caches. Looks like our problem is an impedence
>>> mismatch: global windup counter, per-node cache scan calculations.
>>>
>>> So, that's the mess we really need to cleaning up before going much
>>> further with this patchset. We need stable behaviour from the
>>> shrinkers - I'll look into this a bit deeper tomorrow.
>>
>> That doesn't totally make sense to me.
>>
>> Both our scan and count functions will be per-node now. This means we
>> will always try to keep ourselves within reasonable maximums on a
>> per-node basis as well.
>
> Right, but if we have a bunch of GFP_NOFS reclaims on multiple nodes
> at the same time, we get:
>
> max_pass = shr->count_objects;
> nr = shr->nr_in_batch
> shr->nr_in_batch = 0
> /* total_scan has new delta added */
> /* nothing scanned */
> shr->nr_in_batch += total_scan;
>
> And then the next node does the same, and so on.
>
> What I cut from the above output was the shr->nr_in_batch values.
> They were:
>
> kswapd1-633 [001] 1210443.500045: objects to shrink 4077
> gfp_flags GFP_KERNEL pgs_scanned 32 lru_pgs 7096 cache
> items 623079 delta 1404 total_scan 5481
> kswapd1-633 [001] 1210443.504315: objects to shrink 15138
> gfp_flags GFP_KERNEL pgs_scanned 32 lru_pgs 7224 cache
> items 620936 delta 1375 total_scan 16513
> kswapd3-635 [007] 1210443.510311: objects to shrink 99775
> gfp_flags GFP_KERNEL pgs_scanned 32 lru_pgs 6587 cache
> items 514885 delta 1250 total_scan 101025
> kswapd1-633 [001] 1210443.517440: objects to shrink 96370
> gfp_flags GFP_KERNEL pgs_scanned 32 lru_pgs 7236 cache
> items 613824 delta 1357 total_scan 97727
> kswapd2-634 [006] 1210443.527026: objects to shrink 257854
> gfp_flags GFP_KERNEL pgs_scanned 32 lru_pgs 6831 cache
> items 568610 delta 1331 total_scan 259185
> kswapd3-635 [007] 1210443.573165: objects to shrink 1034342
> gfp_flags GFP_KERNEL pgs_scanned 32 lru_pgs 6089 cache
> items 486408 delta 1277 total_scan 243204
>
> So you can see that the number of objects being deferred is driving
> the total_scan count completely in these cases.
>
> This is over a period of 70ms - shr->nr_in_batch has gone from
> roughly zero to 1034342 because of deferred work. Between these
> traces are hundreds of GFP_NOFS reclaims from all 8 cpus (i.e.
> direct reclaim, every 300-400us on *each* CPU), each adding ~1200 to
> shr->nr_in_batch, and the only thing able to reclaim memory is
> kswapd as it does GFP_KERNEL context reclaim.
>
> IOWs, each kswapd is taking the global windup and applying it to
> each per-node list, when in fact the windup is not distributed that
> way. The trace leading up to this kswapd scan:
>
> kswapd1-633 [001] 1210443.517440: objects to shrink 96370
> gfp_flags GFP_KERNEL pgs_scanned 32 lru_pgs 7236 cache
> items 613824 delta 1357 total_scan 97727
>
> Shows that most of the deferred work has come from CPUs 2, 3, 4 and
> a little from CPU 5. The cpu->node map shows that only CPU 5 is on
> node 1 (cpus 1 and 5 are on node 1), so this means that less than a
> quarter of the work that this node 1 shrinker is being asked to do
> was deferred from node 1. Most of it was deferred from nodes 0, 2
> and 3, and so this work the shrinker is doing is doing nothing to
> relieve the memory pressure on those nodes. So direct reclaim on
> those nodes continues to wind up the nr_in_batch count.
>
> And look at where the per-node cache count and windup is getting to
> at times in this process:
>
> fs_mark-5561 [002] 1210443.555528: objects to shrink 2914436
> gfp_flags GFP_NOFS|GFP_NOWARN|GFP_NORETRY|GFP_COMP|GFP_RECLAIMABLE|GFP_NOTRACK
> pgs_scanned 32 lru_pgs 26591
> cache items 2085764 delta 1254 total_scan 1042882
>
> What we see here is a node with more than 2 million filesystem items cached on
> it. The other nodes are around 500,000 at this point, indicating
> that we definitely have a per-node reclaim imbalance....
>
> IOWs, shr->nr_in_batch can grow much larger than any single node LRU
> list, and the deffered count is only limited to (2 * max_pass).
> Hence if the same node is the one that keeps stealing the global
> shr->nr_in_batch calculation, it will always be a number related to
> the size of the cache on that node. All the other nodes will simply
> keep adding their delta counts to it.
>
> Hence if you've got a node with less cache in it than others, and
> kswapd comes along, it will see a gigantic amount of deferred work
> in nr_in_batch, and then we end up removing a large amount of the
> cache on that node, even though it hasn't had a significant amount
> of pressure. And the node that has pressure continues to wind up
> nr_in_batch until it's the one that gets hit by a kswapd run with
> that wound up nr_in_batch....
>
That makes sense now, thanks. It doesn't seem, however, that any deep
black magic is required to fix this here.
Any reason why proportional scanning wouldn't work ?
If we have a very large nr_in_batch, and many nodes to scan, we can try
dividing them among present nodes in the proportion of existing objects
in the cache.
Or maybe even better, we can make deferring work node aware, so when you
defer, you don't defer to a global pool, but rather to a node copy.
--
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^ permalink raw reply [flat|nested] 151+ messages in thread
* Re: [PATCH v6 12/31] fs: convert inode and dentry shrinking to be node aware
2013-05-16 0:02 ` Dave Chinner
@ 2013-05-16 19:14 ` Glauber Costa
2013-05-16 19:14 ` Glauber Costa
1 sibling, 0 replies; 151+ messages in thread
From: Glauber Costa @ 2013-05-16 19:14 UTC (permalink / raw)
To: Dave Chinner
Cc: Glauber Costa, linux-mm, cgroups, Andrew Morton, Greg Thelen,
kamezawa.hiroyu, Michal Hocko, Johannes Weiner, linux-fsdevel,
Dave Chinner
[-- Attachment #1: Type: text/plain, Size: 1829 bytes --]
> IOWs, shr->nr_in_batch can grow much larger than any single node LRU
> list, and the deffered count is only limited to (2 * max_pass).
> Hence if the same node is the one that keeps stealing the global
> shr->nr_in_batch calculation, it will always be a number related to
> the size of the cache on that node. All the other nodes will simply
> keep adding their delta counts to it.
>
> Hence if you've got a node with less cache in it than others, and
> kswapd comes along, it will see a gigantic amount of deferred work
> in nr_in_batch, and then we end up removing a large amount of the
> cache on that node, even though it hasn't had a significant amount
> of pressure. And the node that has pressure continues to wind up
> nr_in_batch until it's the one that gets hit by a kswapd run with
> that wound up nr_in_batch....
>
> Cheers,
>
> Dave.
>
Ok Dave,
My system in general seems to behave quite differently than this. In
special, I hardly see peaks and the caches fill up very slowly. They
later are pruned but always down to the same level, and then they grow
slowly again, in a triangular fashion. Always within a fairly reasonable
range. This might be because my disks are slower than yours.
It may also be some glitch in my setup. I spent a fair amount of time
today trying to see your behavior but I can't. I will try more tomorrow.
For the time being, what do you think about the following patch (that
obviously need a lot more work, just a PoC) ?
If we are indeed deferring work to unrelated nodes, keeping the deferred
work per-node should help. I don't want to make it a static array
because the shrinker structure tend to be embedded in structures. In
particular, the superblock already have two list_lrus with per-node
static arrays. This will make the sb gigantic. But that is not the main
thing.
[-- Attachment #2: patch.patch --]
[-- Type: text/x-patch, Size: 3334 bytes --]
diff --git a/include/linux/shrinker.h b/include/linux/shrinker.h
index 98be3ab..3edcd7f 100644
--- a/include/linux/shrinker.h
+++ b/include/linux/shrinker.h
@@ -53,7 +53,7 @@ struct shrinker {
/* These are for internal use */
struct list_head list;
- atomic_long_t nr_in_batch; /* objs pending delete */
+ atomic_long_t *nr_in_batch; /* objs pending delete, per node */
};
#define DEFAULT_SEEKS 2 /* A good number if you don't know better. */
extern void register_shrinker(struct shrinker *);
diff --git a/mm/vmscan.c b/mm/vmscan.c
index 35a6a9b..6dddc8d 100644
--- a/mm/vmscan.c
+++ b/mm/vmscan.c
@@ -159,7 +159,14 @@ static unsigned long get_lru_size(struct lruvec *lruvec, enum lru_list lru)
*/
void register_shrinker(struct shrinker *shrinker)
{
- atomic_long_set(&shrinker->nr_in_batch, 0);
+ int i = 0;
+
+ shrinker->nr_in_batch = kmalloc(sizeof(atomic_long_t) * nr_node_ids, GFP_KERNEL);
+ BUG_ON(!shrinker->nr_in_batch); /* obviously bogus */
+
+ for (i = 0; i < nr_node_ids; i++)
+ atomic_long_set(&shrinker->nr_in_batch[i], 0);
+
down_write(&shrinker_rwsem);
list_add_tail(&shrinker->list, &shrinker_list);
up_write(&shrinker_rwsem);
@@ -211,6 +218,7 @@ unsigned long shrink_slab(struct shrink_control *shrinkctl,
{
struct shrinker *shrinker;
unsigned long freed = 0;
+ unsigned long nr_active_nodes = 0;
if (nr_pages_scanned == 0)
nr_pages_scanned = SWAP_CLUSTER_MAX;
@@ -229,6 +237,7 @@ unsigned long shrink_slab(struct shrink_control *shrinkctl,
long new_nr;
long batch_size = shrinker->batch ? shrinker->batch
: SHRINK_BATCH;
+ int nid;
if (shrinker->scan_objects) {
max_pass = shrinker->count_objects(shrinker, shrinkctl);
@@ -238,12 +247,17 @@ unsigned long shrink_slab(struct shrink_control *shrinkctl,
if (max_pass <= 0)
continue;
- /*
- * copy the current shrinker scan count into a local variable
- * and zero it so that other concurrent shrinker invocations
- * don't also do this scanning work.
- */
- nr = atomic_long_xchg(&shrinker->nr_in_batch, 0);
+ nr = 0;
+ for_each_node_mask(nid, shrinkctl->nodes_to_scan) {
+ /*
+ * copy the current shrinker scan count into a local
+ * variable and zero it so that other concurrent
+ * shrinker invocations don't also do this scanning
+ * work.
+ */
+ nr += atomic_long_xchg(&shrinker->nr_in_batch[nid], 0);
+ nr_active_nodes++;
+ }
total_scan = nr;
delta = (4 * nr_pages_scanned) / shrinker->seeks;
@@ -311,17 +325,16 @@ unsigned long shrink_slab(struct shrink_control *shrinkctl,
cond_resched();
}
- /*
- * move the unused scan count back into the shrinker in a
- * manner that handles concurrent updates. If we exhausted the
- * scan, there is no need to do an update.
- */
- if (total_scan > 0)
- new_nr = atomic_long_add_return(total_scan,
- &shrinker->nr_in_batch);
- else
- new_nr = atomic_long_read(&shrinker->nr_in_batch);
+ new_nr = 0;
+ total_scan /= nr_active_nodes;
+ for_each_node_mask(nid, shrinkctl->nodes_to_scan) {
+ if (total_scan > 0)
+ new_nr += atomic_long_add_return(total_scan / nr_active_nodes,
+ &shrinker->nr_in_batch[nid]);
+ else
+ new_nr += atomic_long_read(&shrinker->nr_in_batch[nid]);
+ }
trace_mm_shrink_slab_end(shrinker, freed, nr, new_nr);
}
up_read(&shrinker_rwsem);
^ permalink raw reply related [flat|nested] 151+ messages in thread* Re: [PATCH v6 12/31] fs: convert inode and dentry shrinking to be node aware
@ 2013-05-16 19:14 ` Glauber Costa
0 siblings, 0 replies; 151+ messages in thread
From: Glauber Costa @ 2013-05-16 19:14 UTC (permalink / raw)
To: Dave Chinner
Cc: Glauber Costa, linux-mm, cgroups, Andrew Morton, Greg Thelen,
kamezawa.hiroyu, Michal Hocko, Johannes Weiner, linux-fsdevel,
Dave Chinner
[-- Attachment #1: Type: text/plain, Size: 1829 bytes --]
> IOWs, shr->nr_in_batch can grow much larger than any single node LRU
> list, and the deffered count is only limited to (2 * max_pass).
> Hence if the same node is the one that keeps stealing the global
> shr->nr_in_batch calculation, it will always be a number related to
> the size of the cache on that node. All the other nodes will simply
> keep adding their delta counts to it.
>
> Hence if you've got a node with less cache in it than others, and
> kswapd comes along, it will see a gigantic amount of deferred work
> in nr_in_batch, and then we end up removing a large amount of the
> cache on that node, even though it hasn't had a significant amount
> of pressure. And the node that has pressure continues to wind up
> nr_in_batch until it's the one that gets hit by a kswapd run with
> that wound up nr_in_batch....
>
> Cheers,
>
> Dave.
>
Ok Dave,
My system in general seems to behave quite differently than this. In
special, I hardly see peaks and the caches fill up very slowly. They
later are pruned but always down to the same level, and then they grow
slowly again, in a triangular fashion. Always within a fairly reasonable
range. This might be because my disks are slower than yours.
It may also be some glitch in my setup. I spent a fair amount of time
today trying to see your behavior but I can't. I will try more tomorrow.
For the time being, what do you think about the following patch (that
obviously need a lot more work, just a PoC) ?
If we are indeed deferring work to unrelated nodes, keeping the deferred
work per-node should help. I don't want to make it a static array
because the shrinker structure tend to be embedded in structures. In
particular, the superblock already have two list_lrus with per-node
static arrays. This will make the sb gigantic. But that is not the main
thing.
[-- Attachment #2: patch.patch --]
[-- Type: text/x-patch, Size: 3334 bytes --]
diff --git a/include/linux/shrinker.h b/include/linux/shrinker.h
index 98be3ab..3edcd7f 100644
--- a/include/linux/shrinker.h
+++ b/include/linux/shrinker.h
@@ -53,7 +53,7 @@ struct shrinker {
/* These are for internal use */
struct list_head list;
- atomic_long_t nr_in_batch; /* objs pending delete */
+ atomic_long_t *nr_in_batch; /* objs pending delete, per node */
};
#define DEFAULT_SEEKS 2 /* A good number if you don't know better. */
extern void register_shrinker(struct shrinker *);
diff --git a/mm/vmscan.c b/mm/vmscan.c
index 35a6a9b..6dddc8d 100644
--- a/mm/vmscan.c
+++ b/mm/vmscan.c
@@ -159,7 +159,14 @@ static unsigned long get_lru_size(struct lruvec *lruvec, enum lru_list lru)
*/
void register_shrinker(struct shrinker *shrinker)
{
- atomic_long_set(&shrinker->nr_in_batch, 0);
+ int i = 0;
+
+ shrinker->nr_in_batch = kmalloc(sizeof(atomic_long_t) * nr_node_ids, GFP_KERNEL);
+ BUG_ON(!shrinker->nr_in_batch); /* obviously bogus */
+
+ for (i = 0; i < nr_node_ids; i++)
+ atomic_long_set(&shrinker->nr_in_batch[i], 0);
+
down_write(&shrinker_rwsem);
list_add_tail(&shrinker->list, &shrinker_list);
up_write(&shrinker_rwsem);
@@ -211,6 +218,7 @@ unsigned long shrink_slab(struct shrink_control *shrinkctl,
{
struct shrinker *shrinker;
unsigned long freed = 0;
+ unsigned long nr_active_nodes = 0;
if (nr_pages_scanned == 0)
nr_pages_scanned = SWAP_CLUSTER_MAX;
@@ -229,6 +237,7 @@ unsigned long shrink_slab(struct shrink_control *shrinkctl,
long new_nr;
long batch_size = shrinker->batch ? shrinker->batch
: SHRINK_BATCH;
+ int nid;
if (shrinker->scan_objects) {
max_pass = shrinker->count_objects(shrinker, shrinkctl);
@@ -238,12 +247,17 @@ unsigned long shrink_slab(struct shrink_control *shrinkctl,
if (max_pass <= 0)
continue;
- /*
- * copy the current shrinker scan count into a local variable
- * and zero it so that other concurrent shrinker invocations
- * don't also do this scanning work.
- */
- nr = atomic_long_xchg(&shrinker->nr_in_batch, 0);
+ nr = 0;
+ for_each_node_mask(nid, shrinkctl->nodes_to_scan) {
+ /*
+ * copy the current shrinker scan count into a local
+ * variable and zero it so that other concurrent
+ * shrinker invocations don't also do this scanning
+ * work.
+ */
+ nr += atomic_long_xchg(&shrinker->nr_in_batch[nid], 0);
+ nr_active_nodes++;
+ }
total_scan = nr;
delta = (4 * nr_pages_scanned) / shrinker->seeks;
@@ -311,17 +325,16 @@ unsigned long shrink_slab(struct shrink_control *shrinkctl,
cond_resched();
}
- /*
- * move the unused scan count back into the shrinker in a
- * manner that handles concurrent updates. If we exhausted the
- * scan, there is no need to do an update.
- */
- if (total_scan > 0)
- new_nr = atomic_long_add_return(total_scan,
- &shrinker->nr_in_batch);
- else
- new_nr = atomic_long_read(&shrinker->nr_in_batch);
+ new_nr = 0;
+ total_scan /= nr_active_nodes;
+ for_each_node_mask(nid, shrinkctl->nodes_to_scan) {
+ if (total_scan > 0)
+ new_nr += atomic_long_add_return(total_scan / nr_active_nodes,
+ &shrinker->nr_in_batch[nid]);
+ else
+ new_nr += atomic_long_read(&shrinker->nr_in_batch[nid]);
+ }
trace_mm_shrink_slab_end(shrinker, freed, nr, new_nr);
}
up_read(&shrinker_rwsem);
^ permalink raw reply related [flat|nested] 151+ messages in thread* Re: [PATCH v6 12/31] fs: convert inode and dentry shrinking to be node aware
2013-05-16 19:14 ` Glauber Costa
(?)
@ 2013-05-17 0:51 ` Dave Chinner
2013-05-17 7:29 ` Glauber Costa
-1 siblings, 1 reply; 151+ messages in thread
From: Dave Chinner @ 2013-05-17 0:51 UTC (permalink / raw)
To: Glauber Costa
Cc: Glauber Costa, linux-mm, cgroups, Andrew Morton, Greg Thelen,
kamezawa.hiroyu, Michal Hocko, Johannes Weiner, linux-fsdevel,
Dave Chinner
On Thu, May 16, 2013 at 11:14:50PM +0400, Glauber Costa wrote:
>
> > IOWs, shr->nr_in_batch can grow much larger than any single node LRU
> > list, and the deffered count is only limited to (2 * max_pass).
> > Hence if the same node is the one that keeps stealing the global
> > shr->nr_in_batch calculation, it will always be a number related to
> > the size of the cache on that node. All the other nodes will simply
> > keep adding their delta counts to it.
> >
> > Hence if you've got a node with less cache in it than others, and
> > kswapd comes along, it will see a gigantic amount of deferred work
> > in nr_in_batch, and then we end up removing a large amount of the
> > cache on that node, even though it hasn't had a significant amount
> > of pressure. And the node that has pressure continues to wind up
> > nr_in_batch until it's the one that gets hit by a kswapd run with
> > that wound up nr_in_batch....
> >
> > Cheers,
> >
> > Dave.
> >
> Ok Dave,
>
> My system in general seems to behave quite differently than this. In
> special, I hardly see peaks and the caches fill up very slowly. They
> later are pruned but always down to the same level, and then they grow
> slowly again, in a triangular fashion. Always within a fairly reasonable
> range. This might be because my disks are slower than yours.
Yes, that is the sort of pattern I'd expect from slower disks....
> It may also be some glitch in my setup. I spent a fair amount of time
> today trying to see your behavior but I can't. I will try more tomorrow.
>
> For the time being, what do you think about the following patch (that
> obviously need a lot more work, just a PoC) ?
>
> If we are indeed deferring work to unrelated nodes, keeping the deferred
> work per-node should help. I don't want to make it a static array
> because the shrinker structure tend to be embedded in structures. In
> particular, the superblock already have two list_lrus with per-node
> static arrays. This will make the sb gigantic. But that is not the main
> thing.
I'm not concerned about the size of the superblock structure, to
tell the truth. ;)
What I'd suggest is that the shrinker needs a flags/capabilities
field that indicates we care about per-node accounting, and only use
this method for the shrinkers that can actually do numa aware
shrinking.
> diff --git a/include/linux/shrinker.h b/include/linux/shrinker.h
> index 98be3ab..3edcd7f 100644
> --- a/include/linux/shrinker.h
> +++ b/include/linux/shrinker.h
> @@ -53,7 +53,7 @@ struct shrinker {
>
> /* These are for internal use */
> struct list_head list;
> - atomic_long_t nr_in_batch; /* objs pending delete */
> + atomic_long_t *nr_in_batch; /* objs pending delete, per node */
> };
> #define DEFAULT_SEEKS 2 /* A good number if you don't know better. */
> extern void register_shrinker(struct shrinker *);
> diff --git a/mm/vmscan.c b/mm/vmscan.c
> index 35a6a9b..6dddc8d 100644
> --- a/mm/vmscan.c
> +++ b/mm/vmscan.c
> @@ -159,7 +159,14 @@ static unsigned long get_lru_size(struct lruvec *lruvec, enum lru_list lru)
> */
> void register_shrinker(struct shrinker *shrinker)
> {
> - atomic_long_set(&shrinker->nr_in_batch, 0);
> + int i = 0;
> +
> + shrinker->nr_in_batch = kmalloc(sizeof(atomic_long_t) * nr_node_ids, GFP_KERNEL);
> + BUG_ON(!shrinker->nr_in_batch); /* obviously bogus */
> +
> + for (i = 0; i < nr_node_ids; i++)
> + atomic_long_set(&shrinker->nr_in_batch[i], 0);
> +
just use kzalloc....
> down_write(&shrinker_rwsem);
> list_add_tail(&shrinker->list, &shrinker_list);
> up_write(&shrinker_rwsem);
> @@ -211,6 +218,7 @@ unsigned long shrink_slab(struct shrink_control *shrinkctl,
> {
> struct shrinker *shrinker;
> unsigned long freed = 0;
> + unsigned long nr_active_nodes = 0;
>
> if (nr_pages_scanned == 0)
> nr_pages_scanned = SWAP_CLUSTER_MAX;
> @@ -229,6 +237,7 @@ unsigned long shrink_slab(struct shrink_control *shrinkctl,
> long new_nr;
> long batch_size = shrinker->batch ? shrinker->batch
> : SHRINK_BATCH;
> + int nid;
>
> if (shrinker->scan_objects) {
> max_pass = shrinker->count_objects(shrinker, shrinkctl);
> @@ -238,12 +247,17 @@ unsigned long shrink_slab(struct shrink_control *shrinkctl,
> if (max_pass <= 0)
> continue;
>
> - /*
> - * copy the current shrinker scan count into a local variable
> - * and zero it so that other concurrent shrinker invocations
> - * don't also do this scanning work.
> - */
> - nr = atomic_long_xchg(&shrinker->nr_in_batch, 0);
> + nr = 0;
> + for_each_node_mask(nid, shrinkctl->nodes_to_scan) {
> + /*
> + * copy the current shrinker scan count into a local
> + * variable and zero it so that other concurrent
> + * shrinker invocations don't also do this scanning
> + * work.
> + */
> + nr += atomic_long_xchg(&shrinker->nr_in_batch[nid], 0);
Just a thought - let's rename "nr_in_batch" to
"deferred_scan"....
> + nr_active_nodes++;
> + }
.....
> + total_scan /= nr_active_nodes;
> + for_each_node_mask(nid, shrinkctl->nodes_to_scan) {
> + if (total_scan > 0)
> + new_nr += atomic_long_add_return(total_scan / nr_active_nodes,
> + &shrinker->nr_in_batch[nid]);
(you do the total_scan / nr_active_nodes twice here)
> + else
> + new_nr += atomic_long_read(&shrinker->nr_in_batch[nid]);
>
> + }
I don't think this solves the problem entirely - it still aggregates
multiple nodes together into the one count. It might be better, but
it will still bleed the deferred count from a single node into other
nodes that have no deferred count.
Perhaps we need to factor this code a little first - separate the
calculation from the per-shrinker loop, so we can do something like:
shrink_slab_node(shr, sc, nid)
{
nodemask_clear(sc->nodemask);
nodemask_set(sc->nodemask, nid)
for each shrinker {
deferred_count = atomic_long_xchg(&shr->deferred_scan[nid], 0);
deferred_count = __shrink_slab(shr, sc, deferred_count);
atomic_long_add(deferred_count, &shr->deferred_scan[nid]);
}
}
And the existing shrink_slab function becomes something like:
shrink_slab(shr, sc, nodemask)
{
if (shr->flags & SHRINKER_NUMA_AWARE) {
for_each_node_mask(nid, nodemask)
shrink_slab_node(shr, sc, nid)
return;
}
for each shrinker {
deferred_count = atomic_long_xchg(&shr->deferred_scan[0], 0);
deferred_count = __shrink_slab(shr, sc, deferred_count);
atomic_long_add(deferred_count, &shr->deferred_scan[0]);
}
}
This then makes the deferred count properly node aware when the
underlying shrinker needs it to be, and prevents bleed from one node
to another. I'd much prefer to see us move to an explicitly node
based iteration like this than try to hack more stuff into
shrink_slab() and confuse it further.
The only thing I don't like about this is the extra nodemask needed,
which, like the scan control, would have to sit on the stack.
Suggestions for avoiding that problem are welcome.. :)
Cheers,
Dave.
--
Dave Chinner
david@fromorbit.com
--
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^ permalink raw reply [flat|nested] 151+ messages in thread* Re: [PATCH v6 12/31] fs: convert inode and dentry shrinking to be node aware
2013-05-17 0:51 ` Dave Chinner
@ 2013-05-17 7:29 ` Glauber Costa
0 siblings, 0 replies; 151+ messages in thread
From: Glauber Costa @ 2013-05-17 7:29 UTC (permalink / raw)
To: Dave Chinner
Cc: Glauber Costa, linux-mm, cgroups, Andrew Morton, Greg Thelen,
kamezawa.hiroyu, Michal Hocko, Johannes Weiner, linux-fsdevel,
Dave Chinner
On 05/17/2013 04:51 AM, Dave Chinner wrote:
>> + total_scan /= nr_active_nodes;
>> > + for_each_node_mask(nid, shrinkctl->nodes_to_scan) {
>> > + if (total_scan > 0)
>> > + new_nr += atomic_long_add_return(total_scan / nr_active_nodes,
>> > + &shrinker->nr_in_batch[nid]);
> (you do the total_scan / nr_active_nodes twice here)
>
Thanks. Indeed. As I told you, I boot tested this, but since I haven't
seen the behavior you are seeing, I didn't give it a lot of testing.
I am a lot more interested in finding out if this approach is worth it.
So if you could give something like this a go, that would be awesome.
>> > + else
>> > + new_nr += atomic_long_read(&shrinker->nr_in_batch[nid]);
>> >
>> > + }
> I don't think this solves the problem entirely - it still aggregates
> multiple nodes together into the one count. It might be better, but
> it will still bleed the deferred count from a single node into other
> nodes that have no deferred count.
>
Yes, but only the nodes that are being scan in this moment, no?
If the shrinker is deferring because we returned -1, this means that
nobody was able to shrink anything.
> Perhaps we need to factor this code a little first - separate the
> calculation from the per-shrinker loop, so we can do something like:
>
> shrink_slab_node(shr, sc, nid)
> {
> nodemask_clear(sc->nodemask);
> nodemask_set(sc->nodemask, nid)
> for each shrinker {
> deferred_count = atomic_long_xchg(&shr->deferred_scan[nid], 0);
>
> deferred_count = __shrink_slab(shr, sc, deferred_count);
>
> atomic_long_add(deferred_count, &shr->deferred_scan[nid]);
> }
> }
>
> And the existing shrink_slab function becomes something like:
>
> shrink_slab(shr, sc, nodemask)
> {
> if (shr->flags & SHRINKER_NUMA_AWARE) {
> for_each_node_mask(nid, nodemask)
> shrink_slab_node(shr, sc, nid)
> return;
> }
I am fine with a numa aware flag.
>
> for each shrinker {
> deferred_count = atomic_long_xchg(&shr->deferred_scan[0], 0);
>
> deferred_count = __shrink_slab(shr, sc, deferred_count);
>
> atomic_long_add(deferred_count, &shr->deferred_scan[0]);
> }
> }
>
> This then makes the deferred count properly node aware when the
> underlying shrinker needs it to be, and prevents bleed from one node
> to another. I'd much prefer to see us move to an explicitly node
> based iteration like this than try to hack more stuff into
> shrink_slab() and confuse it further.
>
Except that shrink_slab_node would also defer work, right?
> The only thing I don't like about this is the extra nodemask needed,
> which, like the scan control, would have to sit on the stack.
> Suggestions for avoiding that problem are welcome.. :)
>
I will try to come up with a patch to do all this, and then we can
concretely discuss.
You are also of course welcome to do so as well =)
--
To unsubscribe, send a message with 'unsubscribe linux-mm' in
the body to majordomo@kvack.org. For more info on Linux MM,
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^ permalink raw reply [flat|nested] 151+ messages in thread* Re: [PATCH v6 12/31] fs: convert inode and dentry shrinking to be node aware
@ 2013-05-17 7:29 ` Glauber Costa
0 siblings, 0 replies; 151+ messages in thread
From: Glauber Costa @ 2013-05-17 7:29 UTC (permalink / raw)
To: Dave Chinner
Cc: Glauber Costa, linux-mm, cgroups, Andrew Morton, Greg Thelen,
kamezawa.hiroyu, Michal Hocko, Johannes Weiner, linux-fsdevel,
Dave Chinner
On 05/17/2013 04:51 AM, Dave Chinner wrote:
>> + total_scan /= nr_active_nodes;
>> > + for_each_node_mask(nid, shrinkctl->nodes_to_scan) {
>> > + if (total_scan > 0)
>> > + new_nr += atomic_long_add_return(total_scan / nr_active_nodes,
>> > + &shrinker->nr_in_batch[nid]);
> (you do the total_scan / nr_active_nodes twice here)
>
Thanks. Indeed. As I told you, I boot tested this, but since I haven't
seen the behavior you are seeing, I didn't give it a lot of testing.
I am a lot more interested in finding out if this approach is worth it.
So if you could give something like this a go, that would be awesome.
>> > + else
>> > + new_nr += atomic_long_read(&shrinker->nr_in_batch[nid]);
>> >
>> > + }
> I don't think this solves the problem entirely - it still aggregates
> multiple nodes together into the one count. It might be better, but
> it will still bleed the deferred count from a single node into other
> nodes that have no deferred count.
>
Yes, but only the nodes that are being scan in this moment, no?
If the shrinker is deferring because we returned -1, this means that
nobody was able to shrink anything.
> Perhaps we need to factor this code a little first - separate the
> calculation from the per-shrinker loop, so we can do something like:
>
> shrink_slab_node(shr, sc, nid)
> {
> nodemask_clear(sc->nodemask);
> nodemask_set(sc->nodemask, nid)
> for each shrinker {
> deferred_count = atomic_long_xchg(&shr->deferred_scan[nid], 0);
>
> deferred_count = __shrink_slab(shr, sc, deferred_count);
>
> atomic_long_add(deferred_count, &shr->deferred_scan[nid]);
> }
> }
>
> And the existing shrink_slab function becomes something like:
>
> shrink_slab(shr, sc, nodemask)
> {
> if (shr->flags & SHRINKER_NUMA_AWARE) {
> for_each_node_mask(nid, nodemask)
> shrink_slab_node(shr, sc, nid)
> return;
> }
I am fine with a numa aware flag.
>
> for each shrinker {
> deferred_count = atomic_long_xchg(&shr->deferred_scan[0], 0);
>
> deferred_count = __shrink_slab(shr, sc, deferred_count);
>
> atomic_long_add(deferred_count, &shr->deferred_scan[0]);
> }
> }
>
> This then makes the deferred count properly node aware when the
> underlying shrinker needs it to be, and prevents bleed from one node
> to another. I'd much prefer to see us move to an explicitly node
> based iteration like this than try to hack more stuff into
> shrink_slab() and confuse it further.
>
Except that shrink_slab_node would also defer work, right?
> The only thing I don't like about this is the extra nodemask needed,
> which, like the scan control, would have to sit on the stack.
> Suggestions for avoiding that problem are welcome.. :)
>
I will try to come up with a patch to do all this, and then we can
concretely discuss.
You are also of course welcome to do so as well =)
--
To unsubscribe, send a message with 'unsubscribe linux-mm' in
the body to majordomo@kvack.org. For more info on Linux MM,
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^ permalink raw reply [flat|nested] 151+ messages in thread[parent not found: <5195DC59.8000205-bzQdu9zFT3WakBO8gow8eQ@public.gmane.org>]
* Re: [PATCH v6 12/31] fs: convert inode and dentry shrinking to be node aware
2013-05-17 7:29 ` Glauber Costa
(?)
@ 2013-05-17 14:49 ` Glauber Costa
-1 siblings, 0 replies; 151+ messages in thread
From: Glauber Costa @ 2013-05-17 14:49 UTC (permalink / raw)
To: Dave Chinner
Cc: Glauber Costa, linux-mm-Bw31MaZKKs3YtjvyW6yDsg,
cgroups-u79uwXL29TY76Z2rM5mHXA, Andrew Morton, Greg Thelen,
kamezawa.hiroyu-+CUm20s59erQFUHtdCDX3A, Michal Hocko,
Johannes Weiner, linux-fsdevel-u79uwXL29TY76Z2rM5mHXA,
Dave Chinner
On 05/17/2013 11:29 AM, Glauber Costa wrote:
> Except that shrink_slab_node would also defer work, right?
>
>> > The only thing I don't like about this is the extra nodemask needed,
>> > which, like the scan control, would have to sit on the stack.
>> > Suggestions for avoiding that problem are welcome.. :)
>> >
> I will try to come up with a patch to do all this, and then we can
> concretely discuss.
> You are also of course welcome to do so as well =)
All right.
I played a bit today with variations of this patch that will keep the
deferred count per node. I will rebase the whole series ontop of it (the
changes can get quite disruptive) and post. I want to believe that
after this, all our regression problems will be gone (famous last words).
As I have told you, I wasn't seeing problems like you are, and
speculated that this was due to the disk speeds. While this is true,
the patch I came up with makes my workload actually a lot better.
While my caches weren't being emptied, they were being slightly depleted
and then slowly filled again. With my new patch, it is almost
a straight line throughout the whole find run. There is a dent here and
there eventually, but it recovers quickly. It takes some time as well
for steady state to be reached, but once it is, we have all variables
in the equation (dentries, inodes, etc) basically flat. So I guess it
works, and I am confident that it will make your workload better.
My strategy is to modify the shrinker structure like this:
struct shrinker {
int (*shrink)(struct shrinker *, struct shrink_control *sc);
long (*count_objects)(struct shrinker *, struct shrink_control *sc);
long (*scan_objects)(struct shrinker *, struct shrink_control *sc);
int seeks; /* seeks to recreate an obj */
long batch; /* reclaim batch size, 0 = default */
unsigned long flags;
/* These are for internal use */
struct list_head list;
atomic_long_t *nr_deferred; /* objs pending delete, per node */
/* nodes being currently shrunk, only makes sense for NUMA
shrinkers */
nodemask_t *nodes_shrinking;
};
We need memory allocation now for nr_deferred and nodes_shrinking, but
OTOH we use no stack, and can keep the size of this to be dynamically
adjusted depending on whether or not your shrinker is NUMA aware.
Guess that is it. Expect news soon.
^ permalink raw reply [flat|nested] 151+ messages in thread* Re: [PATCH v6 12/31] fs: convert inode and dentry shrinking to be node aware
@ 2013-05-17 14:49 ` Glauber Costa
0 siblings, 0 replies; 151+ messages in thread
From: Glauber Costa @ 2013-05-17 14:49 UTC (permalink / raw)
To: Dave Chinner
Cc: Glauber Costa, linux-mm-Bw31MaZKKs3YtjvyW6yDsg,
cgroups-u79uwXL29TY76Z2rM5mHXA, Andrew Morton, Greg Thelen,
kamezawa.hiroyu-+CUm20s59erQFUHtdCDX3A, Michal Hocko,
Johannes Weiner, linux-fsdevel-u79uwXL29TY76Z2rM5mHXA,
Dave Chinner
On 05/17/2013 11:29 AM, Glauber Costa wrote:
> Except that shrink_slab_node would also defer work, right?
>
>> > The only thing I don't like about this is the extra nodemask needed,
>> > which, like the scan control, would have to sit on the stack.
>> > Suggestions for avoiding that problem are welcome.. :)
>> >
> I will try to come up with a patch to do all this, and then we can
> concretely discuss.
> You are also of course welcome to do so as well =)
All right.
I played a bit today with variations of this patch that will keep the
deferred count per node. I will rebase the whole series ontop of it (the
changes can get quite disruptive) and post. I want to believe that
after this, all our regression problems will be gone (famous last words).
As I have told you, I wasn't seeing problems like you are, and
speculated that this was due to the disk speeds. While this is true,
the patch I came up with makes my workload actually a lot better.
While my caches weren't being emptied, they were being slightly depleted
and then slowly filled again. With my new patch, it is almost
a straight line throughout the whole find run. There is a dent here and
there eventually, but it recovers quickly. It takes some time as well
for steady state to be reached, but once it is, we have all variables
in the equation (dentries, inodes, etc) basically flat. So I guess it
works, and I am confident that it will make your workload better.
My strategy is to modify the shrinker structure like this:
struct shrinker {
int (*shrink)(struct shrinker *, struct shrink_control *sc);
long (*count_objects)(struct shrinker *, struct shrink_control *sc);
long (*scan_objects)(struct shrinker *, struct shrink_control *sc);
int seeks; /* seeks to recreate an obj */
long batch; /* reclaim batch size, 0 = default */
unsigned long flags;
/* These are for internal use */
struct list_head list;
atomic_long_t *nr_deferred; /* objs pending delete, per node */
/* nodes being currently shrunk, only makes sense for NUMA
shrinkers */
nodemask_t *nodes_shrinking;
};
We need memory allocation now for nr_deferred and nodes_shrinking, but
OTOH we use no stack, and can keep the size of this to be dynamically
adjusted depending on whether or not your shrinker is NUMA aware.
Guess that is it. Expect news soon.
^ permalink raw reply [flat|nested] 151+ messages in thread* Re: [PATCH v6 12/31] fs: convert inode and dentry shrinking to be node aware
@ 2013-05-17 14:49 ` Glauber Costa
0 siblings, 0 replies; 151+ messages in thread
From: Glauber Costa @ 2013-05-17 14:49 UTC (permalink / raw)
To: Dave Chinner
Cc: Glauber Costa, linux-mm, cgroups, Andrew Morton, Greg Thelen,
kamezawa.hiroyu, Michal Hocko, Johannes Weiner, linux-fsdevel,
Dave Chinner
On 05/17/2013 11:29 AM, Glauber Costa wrote:
> Except that shrink_slab_node would also defer work, right?
>
>> > The only thing I don't like about this is the extra nodemask needed,
>> > which, like the scan control, would have to sit on the stack.
>> > Suggestions for avoiding that problem are welcome.. :)
>> >
> I will try to come up with a patch to do all this, and then we can
> concretely discuss.
> You are also of course welcome to do so as well =)
All right.
I played a bit today with variations of this patch that will keep the
deferred count per node. I will rebase the whole series ontop of it (the
changes can get quite disruptive) and post. I want to believe that
after this, all our regression problems will be gone (famous last words).
As I have told you, I wasn't seeing problems like you are, and
speculated that this was due to the disk speeds. While this is true,
the patch I came up with makes my workload actually a lot better.
While my caches weren't being emptied, they were being slightly depleted
and then slowly filled again. With my new patch, it is almost
a straight line throughout the whole find run. There is a dent here and
there eventually, but it recovers quickly. It takes some time as well
for steady state to be reached, but once it is, we have all variables
in the equation (dentries, inodes, etc) basically flat. So I guess it
works, and I am confident that it will make your workload better.
My strategy is to modify the shrinker structure like this:
struct shrinker {
int (*shrink)(struct shrinker *, struct shrink_control *sc);
long (*count_objects)(struct shrinker *, struct shrink_control *sc);
long (*scan_objects)(struct shrinker *, struct shrink_control *sc);
int seeks; /* seeks to recreate an obj */
long batch; /* reclaim batch size, 0 = default */
unsigned long flags;
/* These are for internal use */
struct list_head list;
atomic_long_t *nr_deferred; /* objs pending delete, per node */
/* nodes being currently shrunk, only makes sense for NUMA
shrinkers */
nodemask_t *nodes_shrinking;
};
We need memory allocation now for nr_deferred and nodes_shrinking, but
OTOH we use no stack, and can keep the size of this to be dynamically
adjusted depending on whether or not your shrinker is NUMA aware.
Guess that is it. Expect news soon.
--
To unsubscribe, send a message with 'unsubscribe linux-mm' in
the body to majordomo@kvack.org. For more info on Linux MM,
see: http://www.linux-mm.org/ .
Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a>
^ permalink raw reply [flat|nested] 151+ messages in thread[parent not found: <51964381.8010406-bzQdu9zFT3WakBO8gow8eQ@public.gmane.org>]
* Re: [PATCH v6 12/31] fs: convert inode and dentry shrinking to be node aware
2013-05-17 14:49 ` Glauber Costa
(?)
@ 2013-05-17 22:54 ` Glauber Costa
-1 siblings, 0 replies; 151+ messages in thread
From: Glauber Costa @ 2013-05-17 22:54 UTC (permalink / raw)
To: Dave Chinner
Cc: Glauber Costa, linux-mm-Bw31MaZKKs3YtjvyW6yDsg,
cgroups-u79uwXL29TY76Z2rM5mHXA, Andrew Morton, Greg Thelen,
kamezawa.hiroyu-+CUm20s59erQFUHtdCDX3A, Michal Hocko,
Johannes Weiner, linux-fsdevel-u79uwXL29TY76Z2rM5mHXA,
Dave Chinner
On 05/17/2013 06:49 PM, Glauber Costa wrote:
> On 05/17/2013 11:29 AM, Glauber Costa wrote:
>> Except that shrink_slab_node would also defer work, right?
>>
>>>> The only thing I don't like about this is the extra nodemask needed,
>>>> which, like the scan control, would have to sit on the stack.
>>>> Suggestions for avoiding that problem are welcome.. :)
>>>>
>> I will try to come up with a patch to do all this, and then we can
>> concretely discuss.
>> You are also of course welcome to do so as well =)
>
>
> All right.
>
> I played a bit today with variations of this patch that will keep the
> deferred count per node. I will rebase the whole series ontop of it (the
> changes can get quite disruptive) and post. I want to believe that
> after this, all our regression problems will be gone (famous last words).
>
> As I have told you, I wasn't seeing problems like you are, and
> speculated that this was due to the disk speeds. While this is true,
> the patch I came up with makes my workload actually a lot better.
> While my caches weren't being emptied, they were being slightly depleted
> and then slowly filled again. With my new patch, it is almost
> a straight line throughout the whole find run. There is a dent here and
> there eventually, but it recovers quickly. It takes some time as well
> for steady state to be reached, but once it is, we have all variables
> in the equation (dentries, inodes, etc) basically flat. So I guess it
> works, and I am confident that it will make your workload better.
>
> My strategy is to modify the shrinker structure like this:
>
> struct shrinker {
> int (*shrink)(struct shrinker *, struct shrink_control *sc);
> long (*count_objects)(struct shrinker *, struct shrink_control *sc);
> long (*scan_objects)(struct shrinker *, struct shrink_control *sc);
>
> int seeks; /* seeks to recreate an obj */
> long batch; /* reclaim batch size, 0 = default */
> unsigned long flags;
>
> /* These are for internal use */
> struct list_head list;
> atomic_long_t *nr_deferred; /* objs pending delete, per node */
>
> /* nodes being currently shrunk, only makes sense for NUMA
> shrinkers */
> nodemask_t *nodes_shrinking;
>
> };
>
> We need memory allocation now for nr_deferred and nodes_shrinking, but
> OTOH we use no stack, and can keep the size of this to be dynamically
> adjusted depending on whether or not your shrinker is NUMA aware.
>
> Guess that is it. Expect news soon.
>
Except of course that struct shrinker is obviously shared between runs,
and this won't cut.
Right now I am inclined to really just put this in the stack. The
alternative, if it becomes a problem, can be to extend the lru apis
to allow us to go for a single node. This way we only need to use 1
extra word in the stack.
^ permalink raw reply [flat|nested] 151+ messages in thread* Re: [PATCH v6 12/31] fs: convert inode and dentry shrinking to be node aware
@ 2013-05-17 22:54 ` Glauber Costa
0 siblings, 0 replies; 151+ messages in thread
From: Glauber Costa @ 2013-05-17 22:54 UTC (permalink / raw)
To: Dave Chinner
Cc: Glauber Costa, linux-mm-Bw31MaZKKs3YtjvyW6yDsg,
cgroups-u79uwXL29TY76Z2rM5mHXA, Andrew Morton, Greg Thelen,
kamezawa.hiroyu-+CUm20s59erQFUHtdCDX3A, Michal Hocko,
Johannes Weiner, linux-fsdevel-u79uwXL29TY76Z2rM5mHXA,
Dave Chinner
On 05/17/2013 06:49 PM, Glauber Costa wrote:
> On 05/17/2013 11:29 AM, Glauber Costa wrote:
>> Except that shrink_slab_node would also defer work, right?
>>
>>>> The only thing I don't like about this is the extra nodemask needed,
>>>> which, like the scan control, would have to sit on the stack.
>>>> Suggestions for avoiding that problem are welcome.. :)
>>>>
>> I will try to come up with a patch to do all this, and then we can
>> concretely discuss.
>> You are also of course welcome to do so as well =)
>
>
> All right.
>
> I played a bit today with variations of this patch that will keep the
> deferred count per node. I will rebase the whole series ontop of it (the
> changes can get quite disruptive) and post. I want to believe that
> after this, all our regression problems will be gone (famous last words).
>
> As I have told you, I wasn't seeing problems like you are, and
> speculated that this was due to the disk speeds. While this is true,
> the patch I came up with makes my workload actually a lot better.
> While my caches weren't being emptied, they were being slightly depleted
> and then slowly filled again. With my new patch, it is almost
> a straight line throughout the whole find run. There is a dent here and
> there eventually, but it recovers quickly. It takes some time as well
> for steady state to be reached, but once it is, we have all variables
> in the equation (dentries, inodes, etc) basically flat. So I guess it
> works, and I am confident that it will make your workload better.
>
> My strategy is to modify the shrinker structure like this:
>
> struct shrinker {
> int (*shrink)(struct shrinker *, struct shrink_control *sc);
> long (*count_objects)(struct shrinker *, struct shrink_control *sc);
> long (*scan_objects)(struct shrinker *, struct shrink_control *sc);
>
> int seeks; /* seeks to recreate an obj */
> long batch; /* reclaim batch size, 0 = default */
> unsigned long flags;
>
> /* These are for internal use */
> struct list_head list;
> atomic_long_t *nr_deferred; /* objs pending delete, per node */
>
> /* nodes being currently shrunk, only makes sense for NUMA
> shrinkers */
> nodemask_t *nodes_shrinking;
>
> };
>
> We need memory allocation now for nr_deferred and nodes_shrinking, but
> OTOH we use no stack, and can keep the size of this to be dynamically
> adjusted depending on whether or not your shrinker is NUMA aware.
>
> Guess that is it. Expect news soon.
>
Except of course that struct shrinker is obviously shared between runs,
and this won't cut.
Right now I am inclined to really just put this in the stack. The
alternative, if it becomes a problem, can be to extend the lru apis
to allow us to go for a single node. This way we only need to use 1
extra word in the stack.
^ permalink raw reply [flat|nested] 151+ messages in thread* Re: [PATCH v6 12/31] fs: convert inode and dentry shrinking to be node aware
@ 2013-05-17 22:54 ` Glauber Costa
0 siblings, 0 replies; 151+ messages in thread
From: Glauber Costa @ 2013-05-17 22:54 UTC (permalink / raw)
To: Dave Chinner
Cc: Glauber Costa, linux-mm, cgroups, Andrew Morton, Greg Thelen,
kamezawa.hiroyu, Michal Hocko, Johannes Weiner, linux-fsdevel,
Dave Chinner
On 05/17/2013 06:49 PM, Glauber Costa wrote:
> On 05/17/2013 11:29 AM, Glauber Costa wrote:
>> Except that shrink_slab_node would also defer work, right?
>>
>>>> The only thing I don't like about this is the extra nodemask needed,
>>>> which, like the scan control, would have to sit on the stack.
>>>> Suggestions for avoiding that problem are welcome.. :)
>>>>
>> I will try to come up with a patch to do all this, and then we can
>> concretely discuss.
>> You are also of course welcome to do so as well =)
>
>
> All right.
>
> I played a bit today with variations of this patch that will keep the
> deferred count per node. I will rebase the whole series ontop of it (the
> changes can get quite disruptive) and post. I want to believe that
> after this, all our regression problems will be gone (famous last words).
>
> As I have told you, I wasn't seeing problems like you are, and
> speculated that this was due to the disk speeds. While this is true,
> the patch I came up with makes my workload actually a lot better.
> While my caches weren't being emptied, they were being slightly depleted
> and then slowly filled again. With my new patch, it is almost
> a straight line throughout the whole find run. There is a dent here and
> there eventually, but it recovers quickly. It takes some time as well
> for steady state to be reached, but once it is, we have all variables
> in the equation (dentries, inodes, etc) basically flat. So I guess it
> works, and I am confident that it will make your workload better.
>
> My strategy is to modify the shrinker structure like this:
>
> struct shrinker {
> int (*shrink)(struct shrinker *, struct shrink_control *sc);
> long (*count_objects)(struct shrinker *, struct shrink_control *sc);
> long (*scan_objects)(struct shrinker *, struct shrink_control *sc);
>
> int seeks; /* seeks to recreate an obj */
> long batch; /* reclaim batch size, 0 = default */
> unsigned long flags;
>
> /* These are for internal use */
> struct list_head list;
> atomic_long_t *nr_deferred; /* objs pending delete, per node */
>
> /* nodes being currently shrunk, only makes sense for NUMA
> shrinkers */
> nodemask_t *nodes_shrinking;
>
> };
>
> We need memory allocation now for nr_deferred and nodes_shrinking, but
> OTOH we use no stack, and can keep the size of this to be dynamically
> adjusted depending on whether or not your shrinker is NUMA aware.
>
> Guess that is it. Expect news soon.
>
Except of course that struct shrinker is obviously shared between runs,
and this won't cut.
Right now I am inclined to really just put this in the stack. The
alternative, if it becomes a problem, can be to extend the lru apis
to allow us to go for a single node. This way we only need to use 1
extra word in the stack.
--
To unsubscribe, send a message with 'unsubscribe linux-mm' in
the body to majordomo@kvack.org. For more info on Linux MM,
see: http://www.linux-mm.org/ .
Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a>
^ permalink raw reply [flat|nested] 151+ messages in thread
* Re: [PATCH v6 12/31] fs: convert inode and dentry shrinking to be node aware
2013-05-17 14:49 ` Glauber Costa
` (2 preceding siblings ...)
(?)
@ 2013-05-18 3:39 ` Dave Chinner
2013-05-18 7:20 ` Glauber Costa
-1 siblings, 1 reply; 151+ messages in thread
From: Dave Chinner @ 2013-05-18 3:39 UTC (permalink / raw)
To: Glauber Costa
Cc: Glauber Costa, linux-mm, cgroups, Andrew Morton, Greg Thelen,
kamezawa.hiroyu, Michal Hocko, Johannes Weiner, linux-fsdevel,
Dave Chinner
On Fri, May 17, 2013 at 06:49:37PM +0400, Glauber Costa wrote:
> On 05/17/2013 11:29 AM, Glauber Costa wrote:
> > Except that shrink_slab_node would also defer work, right?
> >
> >> > The only thing I don't like about this is the extra nodemask needed,
> >> > which, like the scan control, would have to sit on the stack.
> >> > Suggestions for avoiding that problem are welcome.. :)
> >> >
> > I will try to come up with a patch to do all this, and then we can
> > concretely discuss.
> > You are also of course welcome to do so as well =)
>
>
> All right.
>
> I played a bit today with variations of this patch that will keep the
> deferred count per node. I will rebase the whole series ontop of it (the
> changes can get quite disruptive) and post. I want to believe that
> after this, all our regression problems will be gone (famous last words).
>
> As I have told you, I wasn't seeing problems like you are, and
> speculated that this was due to the disk speeds. While this is true,
> the patch I came up with makes my workload actually a lot better.
> While my caches weren't being emptied, they were being slightly depleted
> and then slowly filled again. With my new patch, it is almost
> a straight line throughout the whole find run. There is a dent here and
> there eventually, but it recovers quickly. It takes some time as well
> for steady state to be reached, but once it is, we have all variables
> in the equation (dentries, inodes, etc) basically flat. So I guess it
> works, and I am confident that it will make your workload better.
Sounds promising. A non-numa system gives dead flat linesonthat
workload, and that's how I want a numa system to behave as well when
there is even pressure applied across all nodes.
Sorry for not doing more here - I've been flat out the last couple
of days with XFS CRC stuff. Let me know when you have a tree rebased
as far as this patch and I'll run some tests here....
Cheers,
Dave.
--
Dave Chinner
david@fromorbit.com
--
To unsubscribe, send a message with 'unsubscribe linux-mm' in
the body to majordomo@kvack.org. For more info on Linux MM,
see: http://www.linux-mm.org/ .
Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a>
^ permalink raw reply [flat|nested] 151+ messages in thread* Re: [PATCH v6 12/31] fs: convert inode and dentry shrinking to be node aware
2013-05-18 3:39 ` Dave Chinner
2013-05-18 7:20 ` Glauber Costa
@ 2013-05-18 7:20 ` Glauber Costa
0 siblings, 0 replies; 151+ messages in thread
From: Glauber Costa @ 2013-05-18 7:20 UTC (permalink / raw)
To: Dave Chinner
Cc: Glauber Costa, linux-mm-Bw31MaZKKs3YtjvyW6yDsg,
cgroups-u79uwXL29TY76Z2rM5mHXA, Andrew Morton, Greg Thelen,
kamezawa.hiroyu-+CUm20s59erQFUHtdCDX3A, Michal Hocko,
Johannes Weiner, linux-fsdevel-u79uwXL29TY76Z2rM5mHXA,
Dave Chinner
On 05/18/2013 07:39 AM, Dave Chinner wrote:
> Sorry for not doing more here
I forgive you.
^ permalink raw reply [flat|nested] 151+ messages in thread
* Re: [PATCH v6 12/31] fs: convert inode and dentry shrinking to be node aware
@ 2013-05-18 7:20 ` Glauber Costa
0 siblings, 0 replies; 151+ messages in thread
From: Glauber Costa @ 2013-05-18 7:20 UTC (permalink / raw)
To: Dave Chinner
Cc: Glauber Costa, linux-mm-Bw31MaZKKs3YtjvyW6yDsg,
cgroups-u79uwXL29TY76Z2rM5mHXA, Andrew Morton, Greg Thelen,
kamezawa.hiroyu-+CUm20s59erQFUHtdCDX3A, Michal Hocko,
Johannes Weiner, linux-fsdevel-u79uwXL29TY76Z2rM5mHXA,
Dave Chinner
On 05/18/2013 07:39 AM, Dave Chinner wrote:
> Sorry for not doing more here
I forgive you.
^ permalink raw reply [flat|nested] 151+ messages in thread
* Re: [PATCH v6 12/31] fs: convert inode and dentry shrinking to be node aware
@ 2013-05-18 7:20 ` Glauber Costa
0 siblings, 0 replies; 151+ messages in thread
From: Glauber Costa @ 2013-05-18 7:20 UTC (permalink / raw)
To: Dave Chinner
Cc: Glauber Costa, linux-mm, cgroups, Andrew Morton, Greg Thelen,
kamezawa.hiroyu, Michal Hocko, Johannes Weiner, linux-fsdevel,
Dave Chinner
On 05/18/2013 07:39 AM, Dave Chinner wrote:
> Sorry for not doing more here
I forgive you.
--
To unsubscribe, send a message with 'unsubscribe linux-mm' in
the body to majordomo@kvack.org. For more info on Linux MM,
see: http://www.linux-mm.org/ .
Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a>
^ permalink raw reply [flat|nested] 151+ messages in thread
* [PATCH v6 13/31] xfs: convert buftarg LRU to generic code
2013-05-12 18:13 ` Glauber Costa
(?)
@ 2013-05-12 18:13 ` Glauber Costa
-1 siblings, 0 replies; 151+ messages in thread
From: Glauber Costa @ 2013-05-12 18:13 UTC (permalink / raw)
To: linux-mm
Cc: cgroups, Andrew Morton, Greg Thelen, kamezawa.hiroyu,
Michal Hocko, Johannes Weiner, linux-fsdevel, Dave Chinner,
Glauber Costa, Dave Chinner
From: Dave Chinner <dchinner@redhat.com>
Convert the buftarg LRU to use the new generic LRU list and take
advantage of the functionality it supplies to make the buffer cache
shrinker node aware.
Signed-off-by: Glauber Costa <glommer@openvz.org>
Signed-off-by: Dave Chinner <dchinner@redhat.com>
---
fs/xfs/xfs_buf.c | 169 ++++++++++++++++++++++++++-----------------------------
fs/xfs/xfs_buf.h | 5 +-
2 files changed, 81 insertions(+), 93 deletions(-)
diff --git a/fs/xfs/xfs_buf.c b/fs/xfs/xfs_buf.c
index cee0e42..802b65b 100644
--- a/fs/xfs/xfs_buf.c
+++ b/fs/xfs/xfs_buf.c
@@ -85,20 +85,14 @@ xfs_buf_vmap_len(
* The LRU takes a new reference to the buffer so that it will only be freed
* once the shrinker takes the buffer off the LRU.
*/
-STATIC void
+static void
xfs_buf_lru_add(
struct xfs_buf *bp)
{
- struct xfs_buftarg *btp = bp->b_target;
-
- spin_lock(&btp->bt_lru_lock);
- if (list_empty(&bp->b_lru)) {
- atomic_inc(&bp->b_hold);
- list_add_tail(&bp->b_lru, &btp->bt_lru);
- btp->bt_lru_nr++;
+ if (list_lru_add(&bp->b_target->bt_lru, &bp->b_lru)) {
bp->b_lru_flags &= ~_XBF_LRU_DISPOSE;
+ atomic_inc(&bp->b_hold);
}
- spin_unlock(&btp->bt_lru_lock);
}
/*
@@ -107,24 +101,13 @@ xfs_buf_lru_add(
* The unlocked check is safe here because it only occurs when there are not
* b_lru_ref counts left on the inode under the pag->pag_buf_lock. it is there
* to optimise the shrinker removing the buffer from the LRU and calling
- * xfs_buf_free(). i.e. it removes an unnecessary round trip on the
- * bt_lru_lock.
+ * xfs_buf_free().
*/
-STATIC void
+static void
xfs_buf_lru_del(
struct xfs_buf *bp)
{
- struct xfs_buftarg *btp = bp->b_target;
-
- if (list_empty(&bp->b_lru))
- return;
-
- spin_lock(&btp->bt_lru_lock);
- if (!list_empty(&bp->b_lru)) {
- list_del_init(&bp->b_lru);
- btp->bt_lru_nr--;
- }
- spin_unlock(&btp->bt_lru_lock);
+ list_lru_del(&bp->b_target->bt_lru, &bp->b_lru);
}
/*
@@ -151,18 +134,10 @@ xfs_buf_stale(
bp->b_flags &= ~_XBF_DELWRI_Q;
atomic_set(&(bp)->b_lru_ref, 0);
- if (!list_empty(&bp->b_lru)) {
- struct xfs_buftarg *btp = bp->b_target;
-
- spin_lock(&btp->bt_lru_lock);
- if (!list_empty(&bp->b_lru) &&
- !(bp->b_lru_flags & _XBF_LRU_DISPOSE)) {
- list_del_init(&bp->b_lru);
- btp->bt_lru_nr--;
- atomic_dec(&bp->b_hold);
- }
- spin_unlock(&btp->bt_lru_lock);
- }
+ if (!(bp->b_lru_flags & _XBF_LRU_DISPOSE) &&
+ (list_lru_del(&bp->b_target->bt_lru, &bp->b_lru)))
+ atomic_dec(&bp->b_hold);
+
ASSERT(atomic_read(&bp->b_hold) >= 1);
}
@@ -1501,83 +1476,97 @@ xfs_buf_iomove(
* returned. These buffers will have an elevated hold count, so wait on those
* while freeing all the buffers only held by the LRU.
*/
-void
-xfs_wait_buftarg(
- struct xfs_buftarg *btp)
+static enum lru_status
+xfs_buftarg_wait_rele(
+ struct list_head *item,
+ spinlock_t *lru_lock,
+ void *arg)
+
{
- struct xfs_buf *bp;
+ struct xfs_buf *bp = container_of(item, struct xfs_buf, b_lru);
-restart:
- spin_lock(&btp->bt_lru_lock);
- while (!list_empty(&btp->bt_lru)) {
- bp = list_first_entry(&btp->bt_lru, struct xfs_buf, b_lru);
- if (atomic_read(&bp->b_hold) > 1) {
- trace_xfs_buf_wait_buftarg(bp, _RET_IP_);
- list_move_tail(&bp->b_lru, &btp->bt_lru);
- spin_unlock(&btp->bt_lru_lock);
- delay(100);
- goto restart;
- }
+ if (atomic_read(&bp->b_hold) > 1) {
+ /* need to wait */
+ trace_xfs_buf_wait_buftarg(bp, _RET_IP_);
+ spin_unlock(lru_lock);
+ delay(100);
+ } else {
/*
* clear the LRU reference count so the buffer doesn't get
* ignored in xfs_buf_rele().
*/
atomic_set(&bp->b_lru_ref, 0);
- spin_unlock(&btp->bt_lru_lock);
+ spin_unlock(lru_lock);
xfs_buf_rele(bp);
- spin_lock(&btp->bt_lru_lock);
}
- spin_unlock(&btp->bt_lru_lock);
+
+ spin_lock(lru_lock);
+ return LRU_RETRY;
}
-int
-xfs_buftarg_shrink(
+void
+xfs_wait_buftarg(
+ struct xfs_buftarg *btp)
+{
+ while (list_lru_count(&btp->bt_lru))
+ list_lru_walk(&btp->bt_lru, xfs_buftarg_wait_rele,
+ NULL, LONG_MAX);
+}
+
+static enum lru_status
+xfs_buftarg_isolate(
+ struct list_head *item,
+ spinlock_t *lru_lock,
+ void *arg)
+{
+ struct xfs_buf *bp = container_of(item, struct xfs_buf, b_lru);
+ struct list_head *dispose = arg;
+
+ /*
+ * Decrement the b_lru_ref count unless the value is already
+ * zero. If the value is already zero, we need to reclaim the
+ * buffer, otherwise it gets another trip through the LRU.
+ */
+ if (!atomic_add_unless(&bp->b_lru_ref, -1, 0))
+ return LRU_ROTATE;
+
+ bp->b_lru_flags |= _XBF_LRU_DISPOSE;
+ list_move(item, dispose);
+ return LRU_REMOVED;
+}
+
+static long
+xfs_buftarg_shrink_scan(
struct shrinker *shrink,
struct shrink_control *sc)
{
struct xfs_buftarg *btp = container_of(shrink,
struct xfs_buftarg, bt_shrinker);
- struct xfs_buf *bp;
- int nr_to_scan = sc->nr_to_scan;
LIST_HEAD(dispose);
+ long freed;
- if (!nr_to_scan)
- return btp->bt_lru_nr;
-
- spin_lock(&btp->bt_lru_lock);
- while (!list_empty(&btp->bt_lru)) {
- if (nr_to_scan-- <= 0)
- break;
-
- bp = list_first_entry(&btp->bt_lru, struct xfs_buf, b_lru);
-
- /*
- * Decrement the b_lru_ref count unless the value is already
- * zero. If the value is already zero, we need to reclaim the
- * buffer, otherwise it gets another trip through the LRU.
- */
- if (!atomic_add_unless(&bp->b_lru_ref, -1, 0)) {
- list_move_tail(&bp->b_lru, &btp->bt_lru);
- continue;
- }
-
- /*
- * remove the buffer from the LRU now to avoid needing another
- * lock round trip inside xfs_buf_rele().
- */
- list_move(&bp->b_lru, &dispose);
- btp->bt_lru_nr--;
- bp->b_lru_flags |= _XBF_LRU_DISPOSE;
- }
- spin_unlock(&btp->bt_lru_lock);
+ freed = list_lru_walk_nodemask(&btp->bt_lru, xfs_buftarg_isolate,
+ &dispose, sc->nr_to_scan,
+ &sc->nodes_to_scan);
while (!list_empty(&dispose)) {
+ struct xfs_buf *bp;
bp = list_first_entry(&dispose, struct xfs_buf, b_lru);
list_del_init(&bp->b_lru);
xfs_buf_rele(bp);
}
- return btp->bt_lru_nr;
+ return freed;
+}
+
+static long
+xfs_buftarg_shrink_count(
+ struct shrinker *shrink,
+ struct shrink_control *sc)
+{
+ struct xfs_buftarg *btp = container_of(shrink,
+ struct xfs_buftarg, bt_shrinker);
+ return list_lru_count_nodemask(&btp->bt_lru, &sc->nodes_to_scan);
}
void
@@ -1659,11 +1648,11 @@ xfs_alloc_buftarg(
if (!btp->bt_bdi)
goto error;
- INIT_LIST_HEAD(&btp->bt_lru);
- spin_lock_init(&btp->bt_lru_lock);
+ list_lru_init(&btp->bt_lru);
if (xfs_setsize_buftarg_early(btp, bdev))
goto error;
- btp->bt_shrinker.shrink = xfs_buftarg_shrink;
+ btp->bt_shrinker.count_objects = xfs_buftarg_shrink_count;
+ btp->bt_shrinker.scan_objects = xfs_buftarg_shrink_scan;
btp->bt_shrinker.seeks = DEFAULT_SEEKS;
register_shrinker(&btp->bt_shrinker);
return btp;
diff --git a/fs/xfs/xfs_buf.h b/fs/xfs/xfs_buf.h
index 433a12e..5ec7d35 100644
--- a/fs/xfs/xfs_buf.h
+++ b/fs/xfs/xfs_buf.h
@@ -25,6 +25,7 @@
#include <linux/fs.h>
#include <linux/buffer_head.h>
#include <linux/uio.h>
+#include <linux/list_lru.h>
/*
* Base types
@@ -92,9 +93,7 @@ typedef struct xfs_buftarg {
/* LRU control structures */
struct shrinker bt_shrinker;
- struct list_head bt_lru;
- spinlock_t bt_lru_lock;
- unsigned int bt_lru_nr;
+ struct list_lru bt_lru;
} xfs_buftarg_t;
struct xfs_buf;
--
1.8.1.4
^ permalink raw reply related [flat|nested] 151+ messages in thread* [PATCH v6 13/31] xfs: convert buftarg LRU to generic code
@ 2013-05-12 18:13 ` Glauber Costa
0 siblings, 0 replies; 151+ messages in thread
From: Glauber Costa @ 2013-05-12 18:13 UTC (permalink / raw)
To: linux-mm
Cc: cgroups, Andrew Morton, Greg Thelen, kamezawa.hiroyu,
Michal Hocko, Johannes Weiner, linux-fsdevel, Dave Chinner,
Glauber Costa, Dave Chinner
From: Dave Chinner <dchinner@redhat.com>
Convert the buftarg LRU to use the new generic LRU list and take
advantage of the functionality it supplies to make the buffer cache
shrinker node aware.
Signed-off-by: Glauber Costa <glommer@openvz.org>
Signed-off-by: Dave Chinner <dchinner@redhat.com>
---
fs/xfs/xfs_buf.c | 169 ++++++++++++++++++++++++++-----------------------------
fs/xfs/xfs_buf.h | 5 +-
2 files changed, 81 insertions(+), 93 deletions(-)
diff --git a/fs/xfs/xfs_buf.c b/fs/xfs/xfs_buf.c
index cee0e42..802b65b 100644
--- a/fs/xfs/xfs_buf.c
+++ b/fs/xfs/xfs_buf.c
@@ -85,20 +85,14 @@ xfs_buf_vmap_len(
* The LRU takes a new reference to the buffer so that it will only be freed
* once the shrinker takes the buffer off the LRU.
*/
-STATIC void
+static void
xfs_buf_lru_add(
struct xfs_buf *bp)
{
- struct xfs_buftarg *btp = bp->b_target;
-
- spin_lock(&btp->bt_lru_lock);
- if (list_empty(&bp->b_lru)) {
- atomic_inc(&bp->b_hold);
- list_add_tail(&bp->b_lru, &btp->bt_lru);
- btp->bt_lru_nr++;
+ if (list_lru_add(&bp->b_target->bt_lru, &bp->b_lru)) {
bp->b_lru_flags &= ~_XBF_LRU_DISPOSE;
+ atomic_inc(&bp->b_hold);
}
- spin_unlock(&btp->bt_lru_lock);
}
/*
@@ -107,24 +101,13 @@ xfs_buf_lru_add(
* The unlocked check is safe here because it only occurs when there are not
* b_lru_ref counts left on the inode under the pag->pag_buf_lock. it is there
* to optimise the shrinker removing the buffer from the LRU and calling
- * xfs_buf_free(). i.e. it removes an unnecessary round trip on the
- * bt_lru_lock.
+ * xfs_buf_free().
*/
-STATIC void
+static void
xfs_buf_lru_del(
struct xfs_buf *bp)
{
- struct xfs_buftarg *btp = bp->b_target;
-
- if (list_empty(&bp->b_lru))
- return;
-
- spin_lock(&btp->bt_lru_lock);
- if (!list_empty(&bp->b_lru)) {
- list_del_init(&bp->b_lru);
- btp->bt_lru_nr--;
- }
- spin_unlock(&btp->bt_lru_lock);
+ list_lru_del(&bp->b_target->bt_lru, &bp->b_lru);
}
/*
@@ -151,18 +134,10 @@ xfs_buf_stale(
bp->b_flags &= ~_XBF_DELWRI_Q;
atomic_set(&(bp)->b_lru_ref, 0);
- if (!list_empty(&bp->b_lru)) {
- struct xfs_buftarg *btp = bp->b_target;
-
- spin_lock(&btp->bt_lru_lock);
- if (!list_empty(&bp->b_lru) &&
- !(bp->b_lru_flags & _XBF_LRU_DISPOSE)) {
- list_del_init(&bp->b_lru);
- btp->bt_lru_nr--;
- atomic_dec(&bp->b_hold);
- }
- spin_unlock(&btp->bt_lru_lock);
- }
+ if (!(bp->b_lru_flags & _XBF_LRU_DISPOSE) &&
+ (list_lru_del(&bp->b_target->bt_lru, &bp->b_lru)))
+ atomic_dec(&bp->b_hold);
+
ASSERT(atomic_read(&bp->b_hold) >= 1);
}
@@ -1501,83 +1476,97 @@ xfs_buf_iomove(
* returned. These buffers will have an elevated hold count, so wait on those
* while freeing all the buffers only held by the LRU.
*/
-void
-xfs_wait_buftarg(
- struct xfs_buftarg *btp)
+static enum lru_status
+xfs_buftarg_wait_rele(
+ struct list_head *item,
+ spinlock_t *lru_lock,
+ void *arg)
+
{
- struct xfs_buf *bp;
+ struct xfs_buf *bp = container_of(item, struct xfs_buf, b_lru);
-restart:
- spin_lock(&btp->bt_lru_lock);
- while (!list_empty(&btp->bt_lru)) {
- bp = list_first_entry(&btp->bt_lru, struct xfs_buf, b_lru);
- if (atomic_read(&bp->b_hold) > 1) {
- trace_xfs_buf_wait_buftarg(bp, _RET_IP_);
- list_move_tail(&bp->b_lru, &btp->bt_lru);
- spin_unlock(&btp->bt_lru_lock);
- delay(100);
- goto restart;
- }
+ if (atomic_read(&bp->b_hold) > 1) {
+ /* need to wait */
+ trace_xfs_buf_wait_buftarg(bp, _RET_IP_);
+ spin_unlock(lru_lock);
+ delay(100);
+ } else {
/*
* clear the LRU reference count so the buffer doesn't get
* ignored in xfs_buf_rele().
*/
atomic_set(&bp->b_lru_ref, 0);
- spin_unlock(&btp->bt_lru_lock);
+ spin_unlock(lru_lock);
xfs_buf_rele(bp);
- spin_lock(&btp->bt_lru_lock);
}
- spin_unlock(&btp->bt_lru_lock);
+
+ spin_lock(lru_lock);
+ return LRU_RETRY;
}
-int
-xfs_buftarg_shrink(
+void
+xfs_wait_buftarg(
+ struct xfs_buftarg *btp)
+{
+ while (list_lru_count(&btp->bt_lru))
+ list_lru_walk(&btp->bt_lru, xfs_buftarg_wait_rele,
+ NULL, LONG_MAX);
+}
+
+static enum lru_status
+xfs_buftarg_isolate(
+ struct list_head *item,
+ spinlock_t *lru_lock,
+ void *arg)
+{
+ struct xfs_buf *bp = container_of(item, struct xfs_buf, b_lru);
+ struct list_head *dispose = arg;
+
+ /*
+ * Decrement the b_lru_ref count unless the value is already
+ * zero. If the value is already zero, we need to reclaim the
+ * buffer, otherwise it gets another trip through the LRU.
+ */
+ if (!atomic_add_unless(&bp->b_lru_ref, -1, 0))
+ return LRU_ROTATE;
+
+ bp->b_lru_flags |= _XBF_LRU_DISPOSE;
+ list_move(item, dispose);
+ return LRU_REMOVED;
+}
+
+static long
+xfs_buftarg_shrink_scan(
struct shrinker *shrink,
struct shrink_control *sc)
{
struct xfs_buftarg *btp = container_of(shrink,
struct xfs_buftarg, bt_shrinker);
- struct xfs_buf *bp;
- int nr_to_scan = sc->nr_to_scan;
LIST_HEAD(dispose);
+ long freed;
- if (!nr_to_scan)
- return btp->bt_lru_nr;
-
- spin_lock(&btp->bt_lru_lock);
- while (!list_empty(&btp->bt_lru)) {
- if (nr_to_scan-- <= 0)
- break;
-
- bp = list_first_entry(&btp->bt_lru, struct xfs_buf, b_lru);
-
- /*
- * Decrement the b_lru_ref count unless the value is already
- * zero. If the value is already zero, we need to reclaim the
- * buffer, otherwise it gets another trip through the LRU.
- */
- if (!atomic_add_unless(&bp->b_lru_ref, -1, 0)) {
- list_move_tail(&bp->b_lru, &btp->bt_lru);
- continue;
- }
-
- /*
- * remove the buffer from the LRU now to avoid needing another
- * lock round trip inside xfs_buf_rele().
- */
- list_move(&bp->b_lru, &dispose);
- btp->bt_lru_nr--;
- bp->b_lru_flags |= _XBF_LRU_DISPOSE;
- }
- spin_unlock(&btp->bt_lru_lock);
+ freed = list_lru_walk_nodemask(&btp->bt_lru, xfs_buftarg_isolate,
+ &dispose, sc->nr_to_scan,
+ &sc->nodes_to_scan);
while (!list_empty(&dispose)) {
+ struct xfs_buf *bp;
bp = list_first_entry(&dispose, struct xfs_buf, b_lru);
list_del_init(&bp->b_lru);
xfs_buf_rele(bp);
}
- return btp->bt_lru_nr;
+ return freed;
+}
+
+static long
+xfs_buftarg_shrink_count(
+ struct shrinker *shrink,
+ struct shrink_control *sc)
+{
+ struct xfs_buftarg *btp = container_of(shrink,
+ struct xfs_buftarg, bt_shrinker);
+ return list_lru_count_nodemask(&btp->bt_lru, &sc->nodes_to_scan);
}
void
@@ -1659,11 +1648,11 @@ xfs_alloc_buftarg(
if (!btp->bt_bdi)
goto error;
- INIT_LIST_HEAD(&btp->bt_lru);
- spin_lock_init(&btp->bt_lru_lock);
+ list_lru_init(&btp->bt_lru);
if (xfs_setsize_buftarg_early(btp, bdev))
goto error;
- btp->bt_shrinker.shrink = xfs_buftarg_shrink;
+ btp->bt_shrinker.count_objects = xfs_buftarg_shrink_count;
+ btp->bt_shrinker.scan_objects = xfs_buftarg_shrink_scan;
btp->bt_shrinker.seeks = DEFAULT_SEEKS;
register_shrinker(&btp->bt_shrinker);
return btp;
diff --git a/fs/xfs/xfs_buf.h b/fs/xfs/xfs_buf.h
index 433a12e..5ec7d35 100644
--- a/fs/xfs/xfs_buf.h
+++ b/fs/xfs/xfs_buf.h
@@ -25,6 +25,7 @@
#include <linux/fs.h>
#include <linux/buffer_head.h>
#include <linux/uio.h>
+#include <linux/list_lru.h>
/*
* Base types
@@ -92,9 +93,7 @@ typedef struct xfs_buftarg {
/* LRU control structures */
struct shrinker bt_shrinker;
- struct list_head bt_lru;
- spinlock_t bt_lru_lock;
- unsigned int bt_lru_nr;
+ struct list_lru bt_lru;
} xfs_buftarg_t;
struct xfs_buf;
--
1.8.1.4
^ permalink raw reply related [flat|nested] 151+ messages in thread* [PATCH v6 13/31] xfs: convert buftarg LRU to generic code
@ 2013-05-12 18:13 ` Glauber Costa
0 siblings, 0 replies; 151+ messages in thread
From: Glauber Costa @ 2013-05-12 18:13 UTC (permalink / raw)
To: linux-mm
Cc: cgroups, Andrew Morton, Greg Thelen, kamezawa.hiroyu,
Michal Hocko, Johannes Weiner, linux-fsdevel, Dave Chinner,
Glauber Costa, Dave Chinner
From: Dave Chinner <dchinner@redhat.com>
Convert the buftarg LRU to use the new generic LRU list and take
advantage of the functionality it supplies to make the buffer cache
shrinker node aware.
Signed-off-by: Glauber Costa <glommer@openvz.org>
Signed-off-by: Dave Chinner <dchinner@redhat.com>
---
fs/xfs/xfs_buf.c | 169 ++++++++++++++++++++++++++-----------------------------
fs/xfs/xfs_buf.h | 5 +-
2 files changed, 81 insertions(+), 93 deletions(-)
diff --git a/fs/xfs/xfs_buf.c b/fs/xfs/xfs_buf.c
index cee0e42..802b65b 100644
--- a/fs/xfs/xfs_buf.c
+++ b/fs/xfs/xfs_buf.c
@@ -85,20 +85,14 @@ xfs_buf_vmap_len(
* The LRU takes a new reference to the buffer so that it will only be freed
* once the shrinker takes the buffer off the LRU.
*/
-STATIC void
+static void
xfs_buf_lru_add(
struct xfs_buf *bp)
{
- struct xfs_buftarg *btp = bp->b_target;
-
- spin_lock(&btp->bt_lru_lock);
- if (list_empty(&bp->b_lru)) {
- atomic_inc(&bp->b_hold);
- list_add_tail(&bp->b_lru, &btp->bt_lru);
- btp->bt_lru_nr++;
+ if (list_lru_add(&bp->b_target->bt_lru, &bp->b_lru)) {
bp->b_lru_flags &= ~_XBF_LRU_DISPOSE;
+ atomic_inc(&bp->b_hold);
}
- spin_unlock(&btp->bt_lru_lock);
}
/*
@@ -107,24 +101,13 @@ xfs_buf_lru_add(
* The unlocked check is safe here because it only occurs when there are not
* b_lru_ref counts left on the inode under the pag->pag_buf_lock. it is there
* to optimise the shrinker removing the buffer from the LRU and calling
- * xfs_buf_free(). i.e. it removes an unnecessary round trip on the
- * bt_lru_lock.
+ * xfs_buf_free().
*/
-STATIC void
+static void
xfs_buf_lru_del(
struct xfs_buf *bp)
{
- struct xfs_buftarg *btp = bp->b_target;
-
- if (list_empty(&bp->b_lru))
- return;
-
- spin_lock(&btp->bt_lru_lock);
- if (!list_empty(&bp->b_lru)) {
- list_del_init(&bp->b_lru);
- btp->bt_lru_nr--;
- }
- spin_unlock(&btp->bt_lru_lock);
+ list_lru_del(&bp->b_target->bt_lru, &bp->b_lru);
}
/*
@@ -151,18 +134,10 @@ xfs_buf_stale(
bp->b_flags &= ~_XBF_DELWRI_Q;
atomic_set(&(bp)->b_lru_ref, 0);
- if (!list_empty(&bp->b_lru)) {
- struct xfs_buftarg *btp = bp->b_target;
-
- spin_lock(&btp->bt_lru_lock);
- if (!list_empty(&bp->b_lru) &&
- !(bp->b_lru_flags & _XBF_LRU_DISPOSE)) {
- list_del_init(&bp->b_lru);
- btp->bt_lru_nr--;
- atomic_dec(&bp->b_hold);
- }
- spin_unlock(&btp->bt_lru_lock);
- }
+ if (!(bp->b_lru_flags & _XBF_LRU_DISPOSE) &&
+ (list_lru_del(&bp->b_target->bt_lru, &bp->b_lru)))
+ atomic_dec(&bp->b_hold);
+
ASSERT(atomic_read(&bp->b_hold) >= 1);
}
@@ -1501,83 +1476,97 @@ xfs_buf_iomove(
* returned. These buffers will have an elevated hold count, so wait on those
* while freeing all the buffers only held by the LRU.
*/
-void
-xfs_wait_buftarg(
- struct xfs_buftarg *btp)
+static enum lru_status
+xfs_buftarg_wait_rele(
+ struct list_head *item,
+ spinlock_t *lru_lock,
+ void *arg)
+
{
- struct xfs_buf *bp;
+ struct xfs_buf *bp = container_of(item, struct xfs_buf, b_lru);
-restart:
- spin_lock(&btp->bt_lru_lock);
- while (!list_empty(&btp->bt_lru)) {
- bp = list_first_entry(&btp->bt_lru, struct xfs_buf, b_lru);
- if (atomic_read(&bp->b_hold) > 1) {
- trace_xfs_buf_wait_buftarg(bp, _RET_IP_);
- list_move_tail(&bp->b_lru, &btp->bt_lru);
- spin_unlock(&btp->bt_lru_lock);
- delay(100);
- goto restart;
- }
+ if (atomic_read(&bp->b_hold) > 1) {
+ /* need to wait */
+ trace_xfs_buf_wait_buftarg(bp, _RET_IP_);
+ spin_unlock(lru_lock);
+ delay(100);
+ } else {
/*
* clear the LRU reference count so the buffer doesn't get
* ignored in xfs_buf_rele().
*/
atomic_set(&bp->b_lru_ref, 0);
- spin_unlock(&btp->bt_lru_lock);
+ spin_unlock(lru_lock);
xfs_buf_rele(bp);
- spin_lock(&btp->bt_lru_lock);
}
- spin_unlock(&btp->bt_lru_lock);
+
+ spin_lock(lru_lock);
+ return LRU_RETRY;
}
-int
-xfs_buftarg_shrink(
+void
+xfs_wait_buftarg(
+ struct xfs_buftarg *btp)
+{
+ while (list_lru_count(&btp->bt_lru))
+ list_lru_walk(&btp->bt_lru, xfs_buftarg_wait_rele,
+ NULL, LONG_MAX);
+}
+
+static enum lru_status
+xfs_buftarg_isolate(
+ struct list_head *item,
+ spinlock_t *lru_lock,
+ void *arg)
+{
+ struct xfs_buf *bp = container_of(item, struct xfs_buf, b_lru);
+ struct list_head *dispose = arg;
+
+ /*
+ * Decrement the b_lru_ref count unless the value is already
+ * zero. If the value is already zero, we need to reclaim the
+ * buffer, otherwise it gets another trip through the LRU.
+ */
+ if (!atomic_add_unless(&bp->b_lru_ref, -1, 0))
+ return LRU_ROTATE;
+
+ bp->b_lru_flags |= _XBF_LRU_DISPOSE;
+ list_move(item, dispose);
+ return LRU_REMOVED;
+}
+
+static long
+xfs_buftarg_shrink_scan(
struct shrinker *shrink,
struct shrink_control *sc)
{
struct xfs_buftarg *btp = container_of(shrink,
struct xfs_buftarg, bt_shrinker);
- struct xfs_buf *bp;
- int nr_to_scan = sc->nr_to_scan;
LIST_HEAD(dispose);
+ long freed;
- if (!nr_to_scan)
- return btp->bt_lru_nr;
-
- spin_lock(&btp->bt_lru_lock);
- while (!list_empty(&btp->bt_lru)) {
- if (nr_to_scan-- <= 0)
- break;
-
- bp = list_first_entry(&btp->bt_lru, struct xfs_buf, b_lru);
-
- /*
- * Decrement the b_lru_ref count unless the value is already
- * zero. If the value is already zero, we need to reclaim the
- * buffer, otherwise it gets another trip through the LRU.
- */
- if (!atomic_add_unless(&bp->b_lru_ref, -1, 0)) {
- list_move_tail(&bp->b_lru, &btp->bt_lru);
- continue;
- }
-
- /*
- * remove the buffer from the LRU now to avoid needing another
- * lock round trip inside xfs_buf_rele().
- */
- list_move(&bp->b_lru, &dispose);
- btp->bt_lru_nr--;
- bp->b_lru_flags |= _XBF_LRU_DISPOSE;
- }
- spin_unlock(&btp->bt_lru_lock);
+ freed = list_lru_walk_nodemask(&btp->bt_lru, xfs_buftarg_isolate,
+ &dispose, sc->nr_to_scan,
+ &sc->nodes_to_scan);
while (!list_empty(&dispose)) {
+ struct xfs_buf *bp;
bp = list_first_entry(&dispose, struct xfs_buf, b_lru);
list_del_init(&bp->b_lru);
xfs_buf_rele(bp);
}
- return btp->bt_lru_nr;
+ return freed;
+}
+
+static long
+xfs_buftarg_shrink_count(
+ struct shrinker *shrink,
+ struct shrink_control *sc)
+{
+ struct xfs_buftarg *btp = container_of(shrink,
+ struct xfs_buftarg, bt_shrinker);
+ return list_lru_count_nodemask(&btp->bt_lru, &sc->nodes_to_scan);
}
void
@@ -1659,11 +1648,11 @@ xfs_alloc_buftarg(
if (!btp->bt_bdi)
goto error;
- INIT_LIST_HEAD(&btp->bt_lru);
- spin_lock_init(&btp->bt_lru_lock);
+ list_lru_init(&btp->bt_lru);
if (xfs_setsize_buftarg_early(btp, bdev))
goto error;
- btp->bt_shrinker.shrink = xfs_buftarg_shrink;
+ btp->bt_shrinker.count_objects = xfs_buftarg_shrink_count;
+ btp->bt_shrinker.scan_objects = xfs_buftarg_shrink_scan;
btp->bt_shrinker.seeks = DEFAULT_SEEKS;
register_shrinker(&btp->bt_shrinker);
return btp;
diff --git a/fs/xfs/xfs_buf.h b/fs/xfs/xfs_buf.h
index 433a12e..5ec7d35 100644
--- a/fs/xfs/xfs_buf.h
+++ b/fs/xfs/xfs_buf.h
@@ -25,6 +25,7 @@
#include <linux/fs.h>
#include <linux/buffer_head.h>
#include <linux/uio.h>
+#include <linux/list_lru.h>
/*
* Base types
@@ -92,9 +93,7 @@ typedef struct xfs_buftarg {
/* LRU control structures */
struct shrinker bt_shrinker;
- struct list_head bt_lru;
- spinlock_t bt_lru_lock;
- unsigned int bt_lru_nr;
+ struct list_lru bt_lru;
} xfs_buftarg_t;
struct xfs_buf;
--
1.8.1.4
--
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^ permalink raw reply related [flat|nested] 151+ messages in thread
* [PATCH v6 14/31] xfs: convert dquot cache lru to list_lru
2013-05-12 18:13 ` Glauber Costa
(?)
@ 2013-05-12 18:13 ` Glauber Costa
-1 siblings, 0 replies; 151+ messages in thread
From: Glauber Costa @ 2013-05-12 18:13 UTC (permalink / raw)
To: linux-mm
Cc: cgroups, Andrew Morton, Greg Thelen, kamezawa.hiroyu,
Michal Hocko, Johannes Weiner, linux-fsdevel, Dave Chinner,
Dave Chinner, Glauber Costa
From: Dave Chinner <dchinner@redhat.com>
Convert the XFS dquot lru to use the list_lru construct and convert
the shrinker to being node aware.
[ glommer: edited for conflicts + warning fixes ]
Signed-off-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Glauber Costa <glommer@openvz.org>
---
fs/xfs/xfs_dquot.c | 7 +-
fs/xfs/xfs_qm.c | 275 +++++++++++++++++++++++++++--------------------------
fs/xfs/xfs_qm.h | 4 +-
3 files changed, 142 insertions(+), 144 deletions(-)
diff --git a/fs/xfs/xfs_dquot.c b/fs/xfs/xfs_dquot.c
index a41f8bf..4e9178d 100644
--- a/fs/xfs/xfs_dquot.c
+++ b/fs/xfs/xfs_dquot.c
@@ -950,13 +950,8 @@ xfs_qm_dqput_final(
trace_xfs_dqput_free(dqp);
- mutex_lock(&qi->qi_lru_lock);
- if (list_empty(&dqp->q_lru)) {
- list_add_tail(&dqp->q_lru, &qi->qi_lru_list);
- qi->qi_lru_count++;
+ if (list_lru_add(&qi->qi_lru, &dqp->q_lru))
XFS_STATS_INC(xs_qm_dquot_unused);
- }
- mutex_unlock(&qi->qi_lru_lock);
/*
* If we just added a udquot to the freelist, then we want to release
diff --git a/fs/xfs/xfs_qm.c b/fs/xfs/xfs_qm.c
index 7ade175..7beae7d 100644
--- a/fs/xfs/xfs_qm.c
+++ b/fs/xfs/xfs_qm.c
@@ -50,8 +50,9 @@
*/
STATIC int xfs_qm_init_quotainos(xfs_mount_t *);
STATIC int xfs_qm_init_quotainfo(xfs_mount_t *);
-STATIC int xfs_qm_shake(struct shrinker *, struct shrink_control *);
+
+STATIC void xfs_qm_dqfree_one(struct xfs_dquot *dqp);
/*
* We use the batch lookup interface to iterate over the dquots as it
* currently is the only interface into the radix tree code that allows
@@ -196,12 +197,9 @@ xfs_qm_dqpurge(
* We move dquots to the freelist as soon as their reference count
* hits zero, so it really should be on the freelist here.
*/
- mutex_lock(&qi->qi_lru_lock);
ASSERT(!list_empty(&dqp->q_lru));
- list_del_init(&dqp->q_lru);
- qi->qi_lru_count--;
+ list_lru_del(&qi->qi_lru, &dqp->q_lru);
XFS_STATS_DEC(xs_qm_dquot_unused);
- mutex_unlock(&qi->qi_lru_lock);
xfs_qm_dqdestroy(dqp);
@@ -631,6 +629,140 @@ xfs_qm_calc_dquots_per_chunk(
return ndquots;
}
+struct xfs_qm_isolate {
+ struct list_head buffers;
+ struct list_head dispose;
+};
+
+static enum lru_status
+xfs_qm_dquot_isolate(
+ struct list_head *item,
+ spinlock_t *lru_lock,
+ void *arg)
+{
+ struct xfs_dquot *dqp = container_of(item,
+ struct xfs_dquot, q_lru);
+ struct xfs_qm_isolate *isol = arg;
+
+ if (!xfs_dqlock_nowait(dqp))
+ goto out_miss_busy;
+
+ /*
+ * This dquot has acquired a reference in the meantime remove it from
+ * the freelist and try again.
+ */
+ if (dqp->q_nrefs) {
+ xfs_dqunlock(dqp);
+ XFS_STATS_INC(xs_qm_dqwants);
+
+ trace_xfs_dqreclaim_want(dqp);
+ list_del_init(&dqp->q_lru);
+ XFS_STATS_DEC(xs_qm_dquot_unused);
+ return 0;
+ }
+
+ /*
+ * If the dquot is dirty, flush it. If it's already being flushed, just
+ * skip it so there is time for the IO to complete before we try to
+ * reclaim it again on the next LRU pass.
+ */
+ if (!xfs_dqflock_nowait(dqp)) {
+ xfs_dqunlock(dqp);
+ goto out_miss_busy;
+ }
+
+ if (XFS_DQ_IS_DIRTY(dqp)) {
+ struct xfs_buf *bp = NULL;
+ int error;
+
+ trace_xfs_dqreclaim_dirty(dqp);
+
+ /* we have to drop the LRU lock to flush the dquot */
+ spin_unlock(lru_lock);
+
+ error = xfs_qm_dqflush(dqp, &bp);
+ if (error) {
+ xfs_warn(dqp->q_mount, "%s: dquot %p flush failed",
+ __func__, dqp);
+ goto out_unlock_dirty;
+ }
+
+ xfs_buf_delwri_queue(bp, &isol->buffers);
+ xfs_buf_relse(bp);
+ goto out_unlock_dirty;
+ }
+ xfs_dqfunlock(dqp);
+
+ /*
+ * Prevent lookups now that we are past the point of no return.
+ */
+ dqp->dq_flags |= XFS_DQ_FREEING;
+ xfs_dqunlock(dqp);
+
+ ASSERT(dqp->q_nrefs == 0);
+ list_move_tail(&dqp->q_lru, &isol->dispose);
+ XFS_STATS_DEC(xs_qm_dquot_unused);
+ trace_xfs_dqreclaim_done(dqp);
+ XFS_STATS_INC(xs_qm_dqreclaims);
+ return 0;
+
+out_miss_busy:
+ trace_xfs_dqreclaim_busy(dqp);
+ XFS_STATS_INC(xs_qm_dqreclaim_misses);
+ return 2;
+
+out_unlock_dirty:
+ trace_xfs_dqreclaim_busy(dqp);
+ XFS_STATS_INC(xs_qm_dqreclaim_misses);
+ return 3;
+}
+
+static long
+xfs_qm_shrink_scan(
+ struct shrinker *shrink,
+ struct shrink_control *sc)
+{
+ struct xfs_quotainfo *qi = container_of(shrink,
+ struct xfs_quotainfo, qi_shrinker);
+ struct xfs_qm_isolate isol;
+ long freed;
+ int error;
+
+ if ((sc->gfp_mask & (__GFP_FS|__GFP_WAIT)) != (__GFP_FS|__GFP_WAIT))
+ return 0;
+
+ INIT_LIST_HEAD(&isol.buffers);
+ INIT_LIST_HEAD(&isol.dispose);
+
+ freed = list_lru_walk_nodemask(&qi->qi_lru, xfs_qm_dquot_isolate, &isol,
+ sc->nr_to_scan, &sc->nodes_to_scan);
+
+ error = xfs_buf_delwri_submit(&isol.buffers);
+ if (error)
+ xfs_warn(NULL, "%s: dquot reclaim failed", __func__);
+
+ while (!list_empty(&isol.dispose)) {
+ struct xfs_dquot *dqp;
+
+ dqp = list_first_entry(&isol.dispose, struct xfs_dquot, q_lru);
+ list_del_init(&dqp->q_lru);
+ xfs_qm_dqfree_one(dqp);
+ }
+
+ return freed;
+}
+
+static long
+xfs_qm_shrink_count(
+ struct shrinker *shrink,
+ struct shrink_control *sc)
+{
+ struct xfs_quotainfo *qi = container_of(shrink,
+ struct xfs_quotainfo, qi_shrinker);
+
+ return list_lru_count_nodemask(&qi->qi_lru, &sc->nodes_to_scan);
+}
+
/*
* This initializes all the quota information that's kept in the
* mount structure
@@ -661,9 +793,7 @@ xfs_qm_init_quotainfo(
INIT_RADIX_TREE(&qinf->qi_gquota_tree, GFP_NOFS);
mutex_init(&qinf->qi_tree_lock);
- INIT_LIST_HEAD(&qinf->qi_lru_list);
- qinf->qi_lru_count = 0;
- mutex_init(&qinf->qi_lru_lock);
+ list_lru_init(&qinf->qi_lru);
/* mutex used to serialize quotaoffs */
mutex_init(&qinf->qi_quotaofflock);
@@ -729,7 +859,8 @@ xfs_qm_init_quotainfo(
qinf->qi_rtbwarnlimit = XFS_QM_RTBWARNLIMIT;
}
- qinf->qi_shrinker.shrink = xfs_qm_shake;
+ qinf->qi_shrinker.count_objects = xfs_qm_shrink_count;
+ qinf->qi_shrinker.scan_objects = xfs_qm_shrink_scan;
qinf->qi_shrinker.seeks = DEFAULT_SEEKS;
register_shrinker(&qinf->qi_shrinker);
return 0;
@@ -1462,132 +1593,6 @@ xfs_qm_dqfree_one(
xfs_qm_dqdestroy(dqp);
}
-STATIC void
-xfs_qm_dqreclaim_one(
- struct xfs_dquot *dqp,
- struct list_head *buffer_list,
- struct list_head *dispose_list)
-{
- struct xfs_mount *mp = dqp->q_mount;
- struct xfs_quotainfo *qi = mp->m_quotainfo;
- int error;
-
- if (!xfs_dqlock_nowait(dqp))
- goto out_move_tail;
-
- /*
- * This dquot has acquired a reference in the meantime remove it from
- * the freelist and try again.
- */
- if (dqp->q_nrefs) {
- xfs_dqunlock(dqp);
-
- trace_xfs_dqreclaim_want(dqp);
- XFS_STATS_INC(xs_qm_dqwants);
-
- list_del_init(&dqp->q_lru);
- qi->qi_lru_count--;
- XFS_STATS_DEC(xs_qm_dquot_unused);
- return;
- }
-
- /*
- * Try to grab the flush lock. If this dquot is in the process of
- * getting flushed to disk, we don't want to reclaim it.
- */
- if (!xfs_dqflock_nowait(dqp))
- goto out_unlock_move_tail;
-
- if (XFS_DQ_IS_DIRTY(dqp)) {
- struct xfs_buf *bp = NULL;
-
- trace_xfs_dqreclaim_dirty(dqp);
-
- error = xfs_qm_dqflush(dqp, &bp);
- if (error) {
- xfs_warn(mp, "%s: dquot %p flush failed",
- __func__, dqp);
- goto out_unlock_move_tail;
- }
-
- xfs_buf_delwri_queue(bp, buffer_list);
- xfs_buf_relse(bp);
- /*
- * Give the dquot another try on the freelist, as the
- * flushing will take some time.
- */
- goto out_unlock_move_tail;
- }
- xfs_dqfunlock(dqp);
-
- /*
- * Prevent lookups now that we are past the point of no return.
- */
- dqp->dq_flags |= XFS_DQ_FREEING;
- xfs_dqunlock(dqp);
-
- ASSERT(dqp->q_nrefs == 0);
- list_move_tail(&dqp->q_lru, dispose_list);
- qi->qi_lru_count--;
- XFS_STATS_DEC(xs_qm_dquot_unused);
-
- trace_xfs_dqreclaim_done(dqp);
- XFS_STATS_INC(xs_qm_dqreclaims);
- return;
-
- /*
- * Move the dquot to the tail of the list so that we don't spin on it.
- */
-out_unlock_move_tail:
- xfs_dqunlock(dqp);
-out_move_tail:
- list_move_tail(&dqp->q_lru, &qi->qi_lru_list);
- trace_xfs_dqreclaim_busy(dqp);
- XFS_STATS_INC(xs_qm_dqreclaim_misses);
-}
-
-STATIC int
-xfs_qm_shake(
- struct shrinker *shrink,
- struct shrink_control *sc)
-{
- struct xfs_quotainfo *qi =
- container_of(shrink, struct xfs_quotainfo, qi_shrinker);
- int nr_to_scan = sc->nr_to_scan;
- LIST_HEAD (buffer_list);
- LIST_HEAD (dispose_list);
- struct xfs_dquot *dqp;
- int error;
-
- if ((sc->gfp_mask & (__GFP_FS|__GFP_WAIT)) != (__GFP_FS|__GFP_WAIT))
- return 0;
- if (!nr_to_scan)
- goto out;
-
- mutex_lock(&qi->qi_lru_lock);
- while (!list_empty(&qi->qi_lru_list)) {
- if (nr_to_scan-- <= 0)
- break;
- dqp = list_first_entry(&qi->qi_lru_list, struct xfs_dquot,
- q_lru);
- xfs_qm_dqreclaim_one(dqp, &buffer_list, &dispose_list);
- }
- mutex_unlock(&qi->qi_lru_lock);
-
- error = xfs_buf_delwri_submit(&buffer_list);
- if (error)
- xfs_warn(NULL, "%s: dquot reclaim failed", __func__);
-
- while (!list_empty(&dispose_list)) {
- dqp = list_first_entry(&dispose_list, struct xfs_dquot, q_lru);
- list_del_init(&dqp->q_lru);
- xfs_qm_dqfree_one(dqp);
- }
-
-out:
- return vfs_pressure_ratio(qi->qi_lru_count);
-}
-
/*
* Start a transaction and write the incore superblock changes to
* disk. flags parameter indicates which fields have changed.
diff --git a/fs/xfs/xfs_qm.h b/fs/xfs/xfs_qm.h
index 5d16a6e..8173b5e 100644
--- a/fs/xfs/xfs_qm.h
+++ b/fs/xfs/xfs_qm.h
@@ -47,9 +47,7 @@ typedef struct xfs_quotainfo {
struct mutex qi_tree_lock;
xfs_inode_t *qi_uquotaip; /* user quota inode */
xfs_inode_t *qi_gquotaip; /* group quota inode */
- struct list_head qi_lru_list;
- struct mutex qi_lru_lock;
- int qi_lru_count;
+ struct list_lru qi_lru;
int qi_dquots;
time_t qi_btimelimit; /* limit for blks timer */
time_t qi_itimelimit; /* limit for inodes timer */
--
1.8.1.4
^ permalink raw reply related [flat|nested] 151+ messages in thread* [PATCH v6 14/31] xfs: convert dquot cache lru to list_lru
@ 2013-05-12 18:13 ` Glauber Costa
0 siblings, 0 replies; 151+ messages in thread
From: Glauber Costa @ 2013-05-12 18:13 UTC (permalink / raw)
To: linux-mm
Cc: cgroups, Andrew Morton, Greg Thelen, kamezawa.hiroyu,
Michal Hocko, Johannes Weiner, linux-fsdevel, Dave Chinner,
Dave Chinner, Glauber Costa
From: Dave Chinner <dchinner@redhat.com>
Convert the XFS dquot lru to use the list_lru construct and convert
the shrinker to being node aware.
[ glommer: edited for conflicts + warning fixes ]
Signed-off-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Glauber Costa <glommer@openvz.org>
---
fs/xfs/xfs_dquot.c | 7 +-
fs/xfs/xfs_qm.c | 275 +++++++++++++++++++++++++++--------------------------
fs/xfs/xfs_qm.h | 4 +-
3 files changed, 142 insertions(+), 144 deletions(-)
diff --git a/fs/xfs/xfs_dquot.c b/fs/xfs/xfs_dquot.c
index a41f8bf..4e9178d 100644
--- a/fs/xfs/xfs_dquot.c
+++ b/fs/xfs/xfs_dquot.c
@@ -950,13 +950,8 @@ xfs_qm_dqput_final(
trace_xfs_dqput_free(dqp);
- mutex_lock(&qi->qi_lru_lock);
- if (list_empty(&dqp->q_lru)) {
- list_add_tail(&dqp->q_lru, &qi->qi_lru_list);
- qi->qi_lru_count++;
+ if (list_lru_add(&qi->qi_lru, &dqp->q_lru))
XFS_STATS_INC(xs_qm_dquot_unused);
- }
- mutex_unlock(&qi->qi_lru_lock);
/*
* If we just added a udquot to the freelist, then we want to release
diff --git a/fs/xfs/xfs_qm.c b/fs/xfs/xfs_qm.c
index 7ade175..7beae7d 100644
--- a/fs/xfs/xfs_qm.c
+++ b/fs/xfs/xfs_qm.c
@@ -50,8 +50,9 @@
*/
STATIC int xfs_qm_init_quotainos(xfs_mount_t *);
STATIC int xfs_qm_init_quotainfo(xfs_mount_t *);
-STATIC int xfs_qm_shake(struct shrinker *, struct shrink_control *);
+
+STATIC void xfs_qm_dqfree_one(struct xfs_dquot *dqp);
/*
* We use the batch lookup interface to iterate over the dquots as it
* currently is the only interface into the radix tree code that allows
@@ -196,12 +197,9 @@ xfs_qm_dqpurge(
* We move dquots to the freelist as soon as their reference count
* hits zero, so it really should be on the freelist here.
*/
- mutex_lock(&qi->qi_lru_lock);
ASSERT(!list_empty(&dqp->q_lru));
- list_del_init(&dqp->q_lru);
- qi->qi_lru_count--;
+ list_lru_del(&qi->qi_lru, &dqp->q_lru);
XFS_STATS_DEC(xs_qm_dquot_unused);
- mutex_unlock(&qi->qi_lru_lock);
xfs_qm_dqdestroy(dqp);
@@ -631,6 +629,140 @@ xfs_qm_calc_dquots_per_chunk(
return ndquots;
}
+struct xfs_qm_isolate {
+ struct list_head buffers;
+ struct list_head dispose;
+};
+
+static enum lru_status
+xfs_qm_dquot_isolate(
+ struct list_head *item,
+ spinlock_t *lru_lock,
+ void *arg)
+{
+ struct xfs_dquot *dqp = container_of(item,
+ struct xfs_dquot, q_lru);
+ struct xfs_qm_isolate *isol = arg;
+
+ if (!xfs_dqlock_nowait(dqp))
+ goto out_miss_busy;
+
+ /*
+ * This dquot has acquired a reference in the meantime remove it from
+ * the freelist and try again.
+ */
+ if (dqp->q_nrefs) {
+ xfs_dqunlock(dqp);
+ XFS_STATS_INC(xs_qm_dqwants);
+
+ trace_xfs_dqreclaim_want(dqp);
+ list_del_init(&dqp->q_lru);
+ XFS_STATS_DEC(xs_qm_dquot_unused);
+ return 0;
+ }
+
+ /*
+ * If the dquot is dirty, flush it. If it's already being flushed, just
+ * skip it so there is time for the IO to complete before we try to
+ * reclaim it again on the next LRU pass.
+ */
+ if (!xfs_dqflock_nowait(dqp)) {
+ xfs_dqunlock(dqp);
+ goto out_miss_busy;
+ }
+
+ if (XFS_DQ_IS_DIRTY(dqp)) {
+ struct xfs_buf *bp = NULL;
+ int error;
+
+ trace_xfs_dqreclaim_dirty(dqp);
+
+ /* we have to drop the LRU lock to flush the dquot */
+ spin_unlock(lru_lock);
+
+ error = xfs_qm_dqflush(dqp, &bp);
+ if (error) {
+ xfs_warn(dqp->q_mount, "%s: dquot %p flush failed",
+ __func__, dqp);
+ goto out_unlock_dirty;
+ }
+
+ xfs_buf_delwri_queue(bp, &isol->buffers);
+ xfs_buf_relse(bp);
+ goto out_unlock_dirty;
+ }
+ xfs_dqfunlock(dqp);
+
+ /*
+ * Prevent lookups now that we are past the point of no return.
+ */
+ dqp->dq_flags |= XFS_DQ_FREEING;
+ xfs_dqunlock(dqp);
+
+ ASSERT(dqp->q_nrefs == 0);
+ list_move_tail(&dqp->q_lru, &isol->dispose);
+ XFS_STATS_DEC(xs_qm_dquot_unused);
+ trace_xfs_dqreclaim_done(dqp);
+ XFS_STATS_INC(xs_qm_dqreclaims);
+ return 0;
+
+out_miss_busy:
+ trace_xfs_dqreclaim_busy(dqp);
+ XFS_STATS_INC(xs_qm_dqreclaim_misses);
+ return 2;
+
+out_unlock_dirty:
+ trace_xfs_dqreclaim_busy(dqp);
+ XFS_STATS_INC(xs_qm_dqreclaim_misses);
+ return 3;
+}
+
+static long
+xfs_qm_shrink_scan(
+ struct shrinker *shrink,
+ struct shrink_control *sc)
+{
+ struct xfs_quotainfo *qi = container_of(shrink,
+ struct xfs_quotainfo, qi_shrinker);
+ struct xfs_qm_isolate isol;
+ long freed;
+ int error;
+
+ if ((sc->gfp_mask & (__GFP_FS|__GFP_WAIT)) != (__GFP_FS|__GFP_WAIT))
+ return 0;
+
+ INIT_LIST_HEAD(&isol.buffers);
+ INIT_LIST_HEAD(&isol.dispose);
+
+ freed = list_lru_walk_nodemask(&qi->qi_lru, xfs_qm_dquot_isolate, &isol,
+ sc->nr_to_scan, &sc->nodes_to_scan);
+
+ error = xfs_buf_delwri_submit(&isol.buffers);
+ if (error)
+ xfs_warn(NULL, "%s: dquot reclaim failed", __func__);
+
+ while (!list_empty(&isol.dispose)) {
+ struct xfs_dquot *dqp;
+
+ dqp = list_first_entry(&isol.dispose, struct xfs_dquot, q_lru);
+ list_del_init(&dqp->q_lru);
+ xfs_qm_dqfree_one(dqp);
+ }
+
+ return freed;
+}
+
+static long
+xfs_qm_shrink_count(
+ struct shrinker *shrink,
+ struct shrink_control *sc)
+{
+ struct xfs_quotainfo *qi = container_of(shrink,
+ struct xfs_quotainfo, qi_shrinker);
+
+ return list_lru_count_nodemask(&qi->qi_lru, &sc->nodes_to_scan);
+}
+
/*
* This initializes all the quota information that's kept in the
* mount structure
@@ -661,9 +793,7 @@ xfs_qm_init_quotainfo(
INIT_RADIX_TREE(&qinf->qi_gquota_tree, GFP_NOFS);
mutex_init(&qinf->qi_tree_lock);
- INIT_LIST_HEAD(&qinf->qi_lru_list);
- qinf->qi_lru_count = 0;
- mutex_init(&qinf->qi_lru_lock);
+ list_lru_init(&qinf->qi_lru);
/* mutex used to serialize quotaoffs */
mutex_init(&qinf->qi_quotaofflock);
@@ -729,7 +859,8 @@ xfs_qm_init_quotainfo(
qinf->qi_rtbwarnlimit = XFS_QM_RTBWARNLIMIT;
}
- qinf->qi_shrinker.shrink = xfs_qm_shake;
+ qinf->qi_shrinker.count_objects = xfs_qm_shrink_count;
+ qinf->qi_shrinker.scan_objects = xfs_qm_shrink_scan;
qinf->qi_shrinker.seeks = DEFAULT_SEEKS;
register_shrinker(&qinf->qi_shrinker);
return 0;
@@ -1462,132 +1593,6 @@ xfs_qm_dqfree_one(
xfs_qm_dqdestroy(dqp);
}
-STATIC void
-xfs_qm_dqreclaim_one(
- struct xfs_dquot *dqp,
- struct list_head *buffer_list,
- struct list_head *dispose_list)
-{
- struct xfs_mount *mp = dqp->q_mount;
- struct xfs_quotainfo *qi = mp->m_quotainfo;
- int error;
-
- if (!xfs_dqlock_nowait(dqp))
- goto out_move_tail;
-
- /*
- * This dquot has acquired a reference in the meantime remove it from
- * the freelist and try again.
- */
- if (dqp->q_nrefs) {
- xfs_dqunlock(dqp);
-
- trace_xfs_dqreclaim_want(dqp);
- XFS_STATS_INC(xs_qm_dqwants);
-
- list_del_init(&dqp->q_lru);
- qi->qi_lru_count--;
- XFS_STATS_DEC(xs_qm_dquot_unused);
- return;
- }
-
- /*
- * Try to grab the flush lock. If this dquot is in the process of
- * getting flushed to disk, we don't want to reclaim it.
- */
- if (!xfs_dqflock_nowait(dqp))
- goto out_unlock_move_tail;
-
- if (XFS_DQ_IS_DIRTY(dqp)) {
- struct xfs_buf *bp = NULL;
-
- trace_xfs_dqreclaim_dirty(dqp);
-
- error = xfs_qm_dqflush(dqp, &bp);
- if (error) {
- xfs_warn(mp, "%s: dquot %p flush failed",
- __func__, dqp);
- goto out_unlock_move_tail;
- }
-
- xfs_buf_delwri_queue(bp, buffer_list);
- xfs_buf_relse(bp);
- /*
- * Give the dquot another try on the freelist, as the
- * flushing will take some time.
- */
- goto out_unlock_move_tail;
- }
- xfs_dqfunlock(dqp);
-
- /*
- * Prevent lookups now that we are past the point of no return.
- */
- dqp->dq_flags |= XFS_DQ_FREEING;
- xfs_dqunlock(dqp);
-
- ASSERT(dqp->q_nrefs == 0);
- list_move_tail(&dqp->q_lru, dispose_list);
- qi->qi_lru_count--;
- XFS_STATS_DEC(xs_qm_dquot_unused);
-
- trace_xfs_dqreclaim_done(dqp);
- XFS_STATS_INC(xs_qm_dqreclaims);
- return;
-
- /*
- * Move the dquot to the tail of the list so that we don't spin on it.
- */
-out_unlock_move_tail:
- xfs_dqunlock(dqp);
-out_move_tail:
- list_move_tail(&dqp->q_lru, &qi->qi_lru_list);
- trace_xfs_dqreclaim_busy(dqp);
- XFS_STATS_INC(xs_qm_dqreclaim_misses);
-}
-
-STATIC int
-xfs_qm_shake(
- struct shrinker *shrink,
- struct shrink_control *sc)
-{
- struct xfs_quotainfo *qi =
- container_of(shrink, struct xfs_quotainfo, qi_shrinker);
- int nr_to_scan = sc->nr_to_scan;
- LIST_HEAD (buffer_list);
- LIST_HEAD (dispose_list);
- struct xfs_dquot *dqp;
- int error;
-
- if ((sc->gfp_mask & (__GFP_FS|__GFP_WAIT)) != (__GFP_FS|__GFP_WAIT))
- return 0;
- if (!nr_to_scan)
- goto out;
-
- mutex_lock(&qi->qi_lru_lock);
- while (!list_empty(&qi->qi_lru_list)) {
- if (nr_to_scan-- <= 0)
- break;
- dqp = list_first_entry(&qi->qi_lru_list, struct xfs_dquot,
- q_lru);
- xfs_qm_dqreclaim_one(dqp, &buffer_list, &dispose_list);
- }
- mutex_unlock(&qi->qi_lru_lock);
-
- error = xfs_buf_delwri_submit(&buffer_list);
- if (error)
- xfs_warn(NULL, "%s: dquot reclaim failed", __func__);
-
- while (!list_empty(&dispose_list)) {
- dqp = list_first_entry(&dispose_list, struct xfs_dquot, q_lru);
- list_del_init(&dqp->q_lru);
- xfs_qm_dqfree_one(dqp);
- }
-
-out:
- return vfs_pressure_ratio(qi->qi_lru_count);
-}
-
/*
* Start a transaction and write the incore superblock changes to
* disk. flags parameter indicates which fields have changed.
diff --git a/fs/xfs/xfs_qm.h b/fs/xfs/xfs_qm.h
index 5d16a6e..8173b5e 100644
--- a/fs/xfs/xfs_qm.h
+++ b/fs/xfs/xfs_qm.h
@@ -47,9 +47,7 @@ typedef struct xfs_quotainfo {
struct mutex qi_tree_lock;
xfs_inode_t *qi_uquotaip; /* user quota inode */
xfs_inode_t *qi_gquotaip; /* group quota inode */
- struct list_head qi_lru_list;
- struct mutex qi_lru_lock;
- int qi_lru_count;
+ struct list_lru qi_lru;
int qi_dquots;
time_t qi_btimelimit; /* limit for blks timer */
time_t qi_itimelimit; /* limit for inodes timer */
--
1.8.1.4
^ permalink raw reply related [flat|nested] 151+ messages in thread* [PATCH v6 14/31] xfs: convert dquot cache lru to list_lru
@ 2013-05-12 18:13 ` Glauber Costa
0 siblings, 0 replies; 151+ messages in thread
From: Glauber Costa @ 2013-05-12 18:13 UTC (permalink / raw)
To: linux-mm
Cc: cgroups, Andrew Morton, Greg Thelen, kamezawa.hiroyu,
Michal Hocko, Johannes Weiner, linux-fsdevel, Dave Chinner,
Dave Chinner, Glauber Costa
From: Dave Chinner <dchinner@redhat.com>
Convert the XFS dquot lru to use the list_lru construct and convert
the shrinker to being node aware.
[ glommer: edited for conflicts + warning fixes ]
Signed-off-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Glauber Costa <glommer@openvz.org>
---
fs/xfs/xfs_dquot.c | 7 +-
fs/xfs/xfs_qm.c | 275 +++++++++++++++++++++++++++--------------------------
fs/xfs/xfs_qm.h | 4 +-
3 files changed, 142 insertions(+), 144 deletions(-)
diff --git a/fs/xfs/xfs_dquot.c b/fs/xfs/xfs_dquot.c
index a41f8bf..4e9178d 100644
--- a/fs/xfs/xfs_dquot.c
+++ b/fs/xfs/xfs_dquot.c
@@ -950,13 +950,8 @@ xfs_qm_dqput_final(
trace_xfs_dqput_free(dqp);
- mutex_lock(&qi->qi_lru_lock);
- if (list_empty(&dqp->q_lru)) {
- list_add_tail(&dqp->q_lru, &qi->qi_lru_list);
- qi->qi_lru_count++;
+ if (list_lru_add(&qi->qi_lru, &dqp->q_lru))
XFS_STATS_INC(xs_qm_dquot_unused);
- }
- mutex_unlock(&qi->qi_lru_lock);
/*
* If we just added a udquot to the freelist, then we want to release
diff --git a/fs/xfs/xfs_qm.c b/fs/xfs/xfs_qm.c
index 7ade175..7beae7d 100644
--- a/fs/xfs/xfs_qm.c
+++ b/fs/xfs/xfs_qm.c
@@ -50,8 +50,9 @@
*/
STATIC int xfs_qm_init_quotainos(xfs_mount_t *);
STATIC int xfs_qm_init_quotainfo(xfs_mount_t *);
-STATIC int xfs_qm_shake(struct shrinker *, struct shrink_control *);
+
+STATIC void xfs_qm_dqfree_one(struct xfs_dquot *dqp);
/*
* We use the batch lookup interface to iterate over the dquots as it
* currently is the only interface into the radix tree code that allows
@@ -196,12 +197,9 @@ xfs_qm_dqpurge(
* We move dquots to the freelist as soon as their reference count
* hits zero, so it really should be on the freelist here.
*/
- mutex_lock(&qi->qi_lru_lock);
ASSERT(!list_empty(&dqp->q_lru));
- list_del_init(&dqp->q_lru);
- qi->qi_lru_count--;
+ list_lru_del(&qi->qi_lru, &dqp->q_lru);
XFS_STATS_DEC(xs_qm_dquot_unused);
- mutex_unlock(&qi->qi_lru_lock);
xfs_qm_dqdestroy(dqp);
@@ -631,6 +629,140 @@ xfs_qm_calc_dquots_per_chunk(
return ndquots;
}
+struct xfs_qm_isolate {
+ struct list_head buffers;
+ struct list_head dispose;
+};
+
+static enum lru_status
+xfs_qm_dquot_isolate(
+ struct list_head *item,
+ spinlock_t *lru_lock,
+ void *arg)
+{
+ struct xfs_dquot *dqp = container_of(item,
+ struct xfs_dquot, q_lru);
+ struct xfs_qm_isolate *isol = arg;
+
+ if (!xfs_dqlock_nowait(dqp))
+ goto out_miss_busy;
+
+ /*
+ * This dquot has acquired a reference in the meantime remove it from
+ * the freelist and try again.
+ */
+ if (dqp->q_nrefs) {
+ xfs_dqunlock(dqp);
+ XFS_STATS_INC(xs_qm_dqwants);
+
+ trace_xfs_dqreclaim_want(dqp);
+ list_del_init(&dqp->q_lru);
+ XFS_STATS_DEC(xs_qm_dquot_unused);
+ return 0;
+ }
+
+ /*
+ * If the dquot is dirty, flush it. If it's already being flushed, just
+ * skip it so there is time for the IO to complete before we try to
+ * reclaim it again on the next LRU pass.
+ */
+ if (!xfs_dqflock_nowait(dqp)) {
+ xfs_dqunlock(dqp);
+ goto out_miss_busy;
+ }
+
+ if (XFS_DQ_IS_DIRTY(dqp)) {
+ struct xfs_buf *bp = NULL;
+ int error;
+
+ trace_xfs_dqreclaim_dirty(dqp);
+
+ /* we have to drop the LRU lock to flush the dquot */
+ spin_unlock(lru_lock);
+
+ error = xfs_qm_dqflush(dqp, &bp);
+ if (error) {
+ xfs_warn(dqp->q_mount, "%s: dquot %p flush failed",
+ __func__, dqp);
+ goto out_unlock_dirty;
+ }
+
+ xfs_buf_delwri_queue(bp, &isol->buffers);
+ xfs_buf_relse(bp);
+ goto out_unlock_dirty;
+ }
+ xfs_dqfunlock(dqp);
+
+ /*
+ * Prevent lookups now that we are past the point of no return.
+ */
+ dqp->dq_flags |= XFS_DQ_FREEING;
+ xfs_dqunlock(dqp);
+
+ ASSERT(dqp->q_nrefs == 0);
+ list_move_tail(&dqp->q_lru, &isol->dispose);
+ XFS_STATS_DEC(xs_qm_dquot_unused);
+ trace_xfs_dqreclaim_done(dqp);
+ XFS_STATS_INC(xs_qm_dqreclaims);
+ return 0;
+
+out_miss_busy:
+ trace_xfs_dqreclaim_busy(dqp);
+ XFS_STATS_INC(xs_qm_dqreclaim_misses);
+ return 2;
+
+out_unlock_dirty:
+ trace_xfs_dqreclaim_busy(dqp);
+ XFS_STATS_INC(xs_qm_dqreclaim_misses);
+ return 3;
+}
+
+static long
+xfs_qm_shrink_scan(
+ struct shrinker *shrink,
+ struct shrink_control *sc)
+{
+ struct xfs_quotainfo *qi = container_of(shrink,
+ struct xfs_quotainfo, qi_shrinker);
+ struct xfs_qm_isolate isol;
+ long freed;
+ int error;
+
+ if ((sc->gfp_mask & (__GFP_FS|__GFP_WAIT)) != (__GFP_FS|__GFP_WAIT))
+ return 0;
+
+ INIT_LIST_HEAD(&isol.buffers);
+ INIT_LIST_HEAD(&isol.dispose);
+
+ freed = list_lru_walk_nodemask(&qi->qi_lru, xfs_qm_dquot_isolate, &isol,
+ sc->nr_to_scan, &sc->nodes_to_scan);
+
+ error = xfs_buf_delwri_submit(&isol.buffers);
+ if (error)
+ xfs_warn(NULL, "%s: dquot reclaim failed", __func__);
+
+ while (!list_empty(&isol.dispose)) {
+ struct xfs_dquot *dqp;
+
+ dqp = list_first_entry(&isol.dispose, struct xfs_dquot, q_lru);
+ list_del_init(&dqp->q_lru);
+ xfs_qm_dqfree_one(dqp);
+ }
+
+ return freed;
+}
+
+static long
+xfs_qm_shrink_count(
+ struct shrinker *shrink,
+ struct shrink_control *sc)
+{
+ struct xfs_quotainfo *qi = container_of(shrink,
+ struct xfs_quotainfo, qi_shrinker);
+
+ return list_lru_count_nodemask(&qi->qi_lru, &sc->nodes_to_scan);
+}
+
/*
* This initializes all the quota information that's kept in the
* mount structure
@@ -661,9 +793,7 @@ xfs_qm_init_quotainfo(
INIT_RADIX_TREE(&qinf->qi_gquota_tree, GFP_NOFS);
mutex_init(&qinf->qi_tree_lock);
- INIT_LIST_HEAD(&qinf->qi_lru_list);
- qinf->qi_lru_count = 0;
- mutex_init(&qinf->qi_lru_lock);
+ list_lru_init(&qinf->qi_lru);
/* mutex used to serialize quotaoffs */
mutex_init(&qinf->qi_quotaofflock);
@@ -729,7 +859,8 @@ xfs_qm_init_quotainfo(
qinf->qi_rtbwarnlimit = XFS_QM_RTBWARNLIMIT;
}
- qinf->qi_shrinker.shrink = xfs_qm_shake;
+ qinf->qi_shrinker.count_objects = xfs_qm_shrink_count;
+ qinf->qi_shrinker.scan_objects = xfs_qm_shrink_scan;
qinf->qi_shrinker.seeks = DEFAULT_SEEKS;
register_shrinker(&qinf->qi_shrinker);
return 0;
@@ -1462,132 +1593,6 @@ xfs_qm_dqfree_one(
xfs_qm_dqdestroy(dqp);
}
-STATIC void
-xfs_qm_dqreclaim_one(
- struct xfs_dquot *dqp,
- struct list_head *buffer_list,
- struct list_head *dispose_list)
-{
- struct xfs_mount *mp = dqp->q_mount;
- struct xfs_quotainfo *qi = mp->m_quotainfo;
- int error;
-
- if (!xfs_dqlock_nowait(dqp))
- goto out_move_tail;
-
- /*
- * This dquot has acquired a reference in the meantime remove it from
- * the freelist and try again.
- */
- if (dqp->q_nrefs) {
- xfs_dqunlock(dqp);
-
- trace_xfs_dqreclaim_want(dqp);
- XFS_STATS_INC(xs_qm_dqwants);
-
- list_del_init(&dqp->q_lru);
- qi->qi_lru_count--;
- XFS_STATS_DEC(xs_qm_dquot_unused);
- return;
- }
-
- /*
- * Try to grab the flush lock. If this dquot is in the process of
- * getting flushed to disk, we don't want to reclaim it.
- */
- if (!xfs_dqflock_nowait(dqp))
- goto out_unlock_move_tail;
-
- if (XFS_DQ_IS_DIRTY(dqp)) {
- struct xfs_buf *bp = NULL;
-
- trace_xfs_dqreclaim_dirty(dqp);
-
- error = xfs_qm_dqflush(dqp, &bp);
- if (error) {
- xfs_warn(mp, "%s: dquot %p flush failed",
- __func__, dqp);
- goto out_unlock_move_tail;
- }
-
- xfs_buf_delwri_queue(bp, buffer_list);
- xfs_buf_relse(bp);
- /*
- * Give the dquot another try on the freelist, as the
- * flushing will take some time.
- */
- goto out_unlock_move_tail;
- }
- xfs_dqfunlock(dqp);
-
- /*
- * Prevent lookups now that we are past the point of no return.
- */
- dqp->dq_flags |= XFS_DQ_FREEING;
- xfs_dqunlock(dqp);
-
- ASSERT(dqp->q_nrefs == 0);
- list_move_tail(&dqp->q_lru, dispose_list);
- qi->qi_lru_count--;
- XFS_STATS_DEC(xs_qm_dquot_unused);
-
- trace_xfs_dqreclaim_done(dqp);
- XFS_STATS_INC(xs_qm_dqreclaims);
- return;
-
- /*
- * Move the dquot to the tail of the list so that we don't spin on it.
- */
-out_unlock_move_tail:
- xfs_dqunlock(dqp);
-out_move_tail:
- list_move_tail(&dqp->q_lru, &qi->qi_lru_list);
- trace_xfs_dqreclaim_busy(dqp);
- XFS_STATS_INC(xs_qm_dqreclaim_misses);
-}
-
-STATIC int
-xfs_qm_shake(
- struct shrinker *shrink,
- struct shrink_control *sc)
-{
- struct xfs_quotainfo *qi =
- container_of(shrink, struct xfs_quotainfo, qi_shrinker);
- int nr_to_scan = sc->nr_to_scan;
- LIST_HEAD (buffer_list);
- LIST_HEAD (dispose_list);
- struct xfs_dquot *dqp;
- int error;
-
- if ((sc->gfp_mask & (__GFP_FS|__GFP_WAIT)) != (__GFP_FS|__GFP_WAIT))
- return 0;
- if (!nr_to_scan)
- goto out;
-
- mutex_lock(&qi->qi_lru_lock);
- while (!list_empty(&qi->qi_lru_list)) {
- if (nr_to_scan-- <= 0)
- break;
- dqp = list_first_entry(&qi->qi_lru_list, struct xfs_dquot,
- q_lru);
- xfs_qm_dqreclaim_one(dqp, &buffer_list, &dispose_list);
- }
- mutex_unlock(&qi->qi_lru_lock);
-
- error = xfs_buf_delwri_submit(&buffer_list);
- if (error)
- xfs_warn(NULL, "%s: dquot reclaim failed", __func__);
-
- while (!list_empty(&dispose_list)) {
- dqp = list_first_entry(&dispose_list, struct xfs_dquot, q_lru);
- list_del_init(&dqp->q_lru);
- xfs_qm_dqfree_one(dqp);
- }
-
-out:
- return vfs_pressure_ratio(qi->qi_lru_count);
-}
-
/*
* Start a transaction and write the incore superblock changes to
* disk. flags parameter indicates which fields have changed.
diff --git a/fs/xfs/xfs_qm.h b/fs/xfs/xfs_qm.h
index 5d16a6e..8173b5e 100644
--- a/fs/xfs/xfs_qm.h
+++ b/fs/xfs/xfs_qm.h
@@ -47,9 +47,7 @@ typedef struct xfs_quotainfo {
struct mutex qi_tree_lock;
xfs_inode_t *qi_uquotaip; /* user quota inode */
xfs_inode_t *qi_gquotaip; /* group quota inode */
- struct list_head qi_lru_list;
- struct mutex qi_lru_lock;
- int qi_lru_count;
+ struct list_lru qi_lru;
int qi_dquots;
time_t qi_btimelimit; /* limit for blks timer */
time_t qi_itimelimit; /* limit for inodes timer */
--
1.8.1.4
--
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^ permalink raw reply related [flat|nested] 151+ messages in thread
* [PATCH v6 15/31] fs: convert fs shrinkers to new scan/count API
2013-05-12 18:13 ` Glauber Costa
(?)
@ 2013-05-12 18:13 ` Glauber Costa
-1 siblings, 0 replies; 151+ messages in thread
From: Glauber Costa @ 2013-05-12 18:13 UTC (permalink / raw)
To: linux-mm
Cc: cgroups, Andrew Morton, Greg Thelen, kamezawa.hiroyu,
Michal Hocko, Johannes Weiner, linux-fsdevel, Dave Chinner,
Dave Chinner, Glauber Costa, Steven Whitehouse, Artem Bityutskiy,
Adrian Hunter, Jan Kara
From: Dave Chinner <dchinner@redhat.com>
Convert the filesystem shrinkers to use the new API, and standardise
some of the behaviours of the shrinkers at the same time. For
example, nr_to_scan means the number of objects to scan, not the
number of objects to free.
I refactored the CIFS idmap shrinker a little - it really needs to
be broken up into a shrinker per tree and keep an item count with
the tree root so that we don't need to walk the tree every time the
shrinker needs to count the number of objects in the tree (i.e.
all the time under memory pressure).
[ glommer: fixes for ext4, ubifs, nfs, cifs and glock. Fixes are
needed mainly due to new code merged in the tree ]
Signed-off-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Glauber Costa <glommer@openvz.org>
Acked-by: Mel Gorman <mgorman@suse.de>
CC: Steven Whitehouse <swhiteho@redhat.com>
CC: Artem Bityutskiy <dedekind1@gmail.com>
CC: Adrian Hunter <adrian.hunter@intel.com>
CC: Jan Kara <jack@suse.cz>
---
fs/ext4/extents_status.c | 30 ++++++++++++++++------------
fs/gfs2/glock.c | 28 +++++++++++++++-----------
fs/gfs2/main.c | 3 ++-
fs/gfs2/quota.c | 12 +++++++-----
fs/gfs2/quota.h | 4 +++-
fs/mbcache.c | 51 ++++++++++++++++++++++++++++--------------------
fs/nfs/dir.c | 18 ++++++++++++++---
fs/nfs/internal.h | 4 +++-
fs/nfs/super.c | 3 ++-
fs/nfsd/nfscache.c | 31 ++++++++++++++++++++---------
fs/quota/dquot.c | 34 +++++++++++++++-----------------
fs/ubifs/shrinker.c | 20 +++++++++++--------
fs/ubifs/super.c | 3 ++-
fs/ubifs/ubifs.h | 3 ++-
14 files changed, 151 insertions(+), 93 deletions(-)
diff --git a/fs/ext4/extents_status.c b/fs/ext4/extents_status.c
index e6941e6..4bce4f0 100644
--- a/fs/ext4/extents_status.c
+++ b/fs/ext4/extents_status.c
@@ -878,20 +878,26 @@ int ext4_es_zeroout(struct inode *inode, struct ext4_extent *ex)
EXTENT_STATUS_WRITTEN);
}
-static int ext4_es_shrink(struct shrinker *shrink, struct shrink_control *sc)
+
+static long ext4_es_count(struct shrinker *shrink, struct shrink_control *sc)
+{
+ long nr;
+ struct ext4_sb_info *sbi = container_of(shrink,
+ struct ext4_sb_info, s_es_shrinker);
+
+ nr = percpu_counter_read_positive(&sbi->s_extent_cache_cnt);
+ trace_ext4_es_shrink_enter(sbi->s_sb, sc->nr_to_scan, nr);
+ return nr;
+}
+
+static long ext4_es_scan(struct shrinker *shrink, struct shrink_control *sc)
{
struct ext4_sb_info *sbi = container_of(shrink,
struct ext4_sb_info, s_es_shrinker);
struct ext4_inode_info *ei;
struct list_head *cur, *tmp, scanned;
int nr_to_scan = sc->nr_to_scan;
- int ret, nr_shrunk = 0;
-
- ret = percpu_counter_read_positive(&sbi->s_extent_cache_cnt);
- trace_ext4_es_shrink_enter(sbi->s_sb, nr_to_scan, ret);
-
- if (!nr_to_scan)
- return ret;
+ int ret = 0, nr_shrunk = 0;
INIT_LIST_HEAD(&scanned);
@@ -920,9 +926,8 @@ static int ext4_es_shrink(struct shrinker *shrink, struct shrink_control *sc)
list_splice_tail(&scanned, &sbi->s_es_lru);
spin_unlock(&sbi->s_es_lru_lock);
- ret = percpu_counter_read_positive(&sbi->s_extent_cache_cnt);
trace_ext4_es_shrink_exit(sbi->s_sb, nr_shrunk, ret);
- return ret;
+ return nr_shrunk;
}
void ext4_es_register_shrinker(struct super_block *sb)
@@ -932,7 +937,8 @@ void ext4_es_register_shrinker(struct super_block *sb)
sbi = EXT4_SB(sb);
INIT_LIST_HEAD(&sbi->s_es_lru);
spin_lock_init(&sbi->s_es_lru_lock);
- sbi->s_es_shrinker.shrink = ext4_es_shrink;
+ sbi->s_es_shrinker.scan_objects = ext4_es_scan;
+ sbi->s_es_shrinker.count_objects = ext4_es_count;
sbi->s_es_shrinker.seeks = DEFAULT_SEEKS;
register_shrinker(&sbi->s_es_shrinker);
}
@@ -973,7 +979,7 @@ static int __es_try_to_reclaim_extents(struct ext4_inode_info *ei,
struct ext4_es_tree *tree = &ei->i_es_tree;
struct rb_node *node;
struct extent_status *es;
- int nr_shrunk = 0;
+ long nr_shrunk = 0;
if (ei->i_es_lru_nr == 0)
return 0;
diff --git a/fs/gfs2/glock.c b/fs/gfs2/glock.c
index 3bd2748..4ddbccb 100644
--- a/fs/gfs2/glock.c
+++ b/fs/gfs2/glock.c
@@ -1428,21 +1428,22 @@ __acquires(&lru_lock)
* gfs2_dispose_glock_lru() above.
*/
-static void gfs2_scan_glock_lru(int nr)
+static long gfs2_scan_glock_lru(int nr)
{
struct gfs2_glock *gl;
LIST_HEAD(skipped);
LIST_HEAD(dispose);
+ long freed = 0;
spin_lock(&lru_lock);
- while(nr && !list_empty(&lru_list)) {
+ while ((nr-- >= 0) && !list_empty(&lru_list)) {
gl = list_entry(lru_list.next, struct gfs2_glock, gl_lru);
/* Test for being demotable */
if (!test_and_set_bit(GLF_LOCK, &gl->gl_flags)) {
list_move(&gl->gl_lru, &dispose);
atomic_dec(&lru_count);
- nr--;
+ freed++;
continue;
}
@@ -1452,23 +1453,28 @@ static void gfs2_scan_glock_lru(int nr)
if (!list_empty(&dispose))
gfs2_dispose_glock_lru(&dispose);
spin_unlock(&lru_lock);
+
+ return freed;
}
-static int gfs2_shrink_glock_memory(struct shrinker *shrink,
- struct shrink_control *sc)
+static long gfs2_glock_shrink_scan(struct shrinker *shrink,
+ struct shrink_control *sc)
{
- if (sc->nr_to_scan) {
- if (!(sc->gfp_mask & __GFP_FS))
- return -1;
- gfs2_scan_glock_lru(sc->nr_to_scan);
- }
+ if (!(sc->gfp_mask & __GFP_FS))
+ return -1;
+ return gfs2_scan_glock_lru(sc->nr_to_scan);
+}
+static long gfs2_glock_shrink_count(struct shrinker *shrink,
+ struct shrink_control *sc)
+{
return vfs_pressure_ratio(atomic_read(&lru_count));
}
static struct shrinker glock_shrinker = {
- .shrink = gfs2_shrink_glock_memory,
.seeks = DEFAULT_SEEKS,
+ .count_objects = gfs2_glock_shrink_count,
+ .scan_objects = gfs2_glock_shrink_scan,
};
/**
diff --git a/fs/gfs2/main.c b/fs/gfs2/main.c
index e04d0e0..a105d84 100644
--- a/fs/gfs2/main.c
+++ b/fs/gfs2/main.c
@@ -32,7 +32,8 @@
struct workqueue_struct *gfs2_control_wq;
static struct shrinker qd_shrinker = {
- .shrink = gfs2_shrink_qd_memory,
+ .count_objects = gfs2_qd_shrink_count,
+ .scan_objects = gfs2_qd_shrink_scan,
.seeks = DEFAULT_SEEKS,
};
diff --git a/fs/gfs2/quota.c b/fs/gfs2/quota.c
index 5c14206..77b82f6 100644
--- a/fs/gfs2/quota.c
+++ b/fs/gfs2/quota.c
@@ -75,14 +75,12 @@ static LIST_HEAD(qd_lru_list);
static atomic_t qd_lru_count = ATOMIC_INIT(0);
static DEFINE_SPINLOCK(qd_lru_lock);
-int gfs2_shrink_qd_memory(struct shrinker *shrink, struct shrink_control *sc)
+long gfs2_qd_shrink_scan(struct shrinker *shrink, struct shrink_control *sc)
{
struct gfs2_quota_data *qd;
struct gfs2_sbd *sdp;
int nr_to_scan = sc->nr_to_scan;
-
- if (nr_to_scan == 0)
- goto out;
+ long freed = 0;
if (!(sc->gfp_mask & __GFP_FS))
return -1;
@@ -110,10 +108,14 @@ int gfs2_shrink_qd_memory(struct shrinker *shrink, struct shrink_control *sc)
kmem_cache_free(gfs2_quotad_cachep, qd);
spin_lock(&qd_lru_lock);
nr_to_scan--;
+ freed++;
}
spin_unlock(&qd_lru_lock);
+ return freed;
+}
-out:
+long gfs2_qd_shrink_count(struct shrinker *shrink, struct shrink_control *sc)
+{
return vfs_pressure_ratio(atomic_read(&qd_lru_count));
}
diff --git a/fs/gfs2/quota.h b/fs/gfs2/quota.h
index 4f5e6e4..4f61708 100644
--- a/fs/gfs2/quota.h
+++ b/fs/gfs2/quota.h
@@ -53,7 +53,9 @@ static inline int gfs2_quota_lock_check(struct gfs2_inode *ip)
return ret;
}
-extern int gfs2_shrink_qd_memory(struct shrinker *shrink,
+extern long gfs2_qd_shrink_count(struct shrinker *shrink,
+ struct shrink_control *sc);
+extern long gfs2_qd_shrink_scan(struct shrinker *shrink,
struct shrink_control *sc);
extern const struct quotactl_ops gfs2_quotactl_ops;
diff --git a/fs/mbcache.c b/fs/mbcache.c
index 5eb0476..009a463 100644
--- a/fs/mbcache.c
+++ b/fs/mbcache.c
@@ -86,18 +86,6 @@ static LIST_HEAD(mb_cache_list);
static LIST_HEAD(mb_cache_lru_list);
static DEFINE_SPINLOCK(mb_cache_spinlock);
-/*
- * What the mbcache registers as to get shrunk dynamically.
- */
-
-static int mb_cache_shrink_fn(struct shrinker *shrink,
- struct shrink_control *sc);
-
-static struct shrinker mb_cache_shrinker = {
- .shrink = mb_cache_shrink_fn,
- .seeks = DEFAULT_SEEKS,
-};
-
static inline int
__mb_cache_entry_is_hashed(struct mb_cache_entry *ce)
{
@@ -151,7 +139,7 @@ forget:
/*
- * mb_cache_shrink_fn() memory pressure callback
+ * mb_cache_shrink_scan() memory pressure callback
*
* This function is called by the kernel memory management when memory
* gets low.
@@ -159,17 +147,18 @@ forget:
* @shrink: (ignored)
* @sc: shrink_control passed from reclaim
*
- * Returns the number of objects which are present in the cache.
+ * Returns the number of objects freed.
*/
-static int
-mb_cache_shrink_fn(struct shrinker *shrink, struct shrink_control *sc)
+static long
+mb_cache_shrink_scan(
+ struct shrinker *shrink,
+ struct shrink_control *sc)
{
LIST_HEAD(free_list);
- struct mb_cache *cache;
struct mb_cache_entry *entry, *tmp;
- int count = 0;
int nr_to_scan = sc->nr_to_scan;
gfp_t gfp_mask = sc->gfp_mask;
+ long freed = 0;
mb_debug("trying to free %d entries", nr_to_scan);
spin_lock(&mb_cache_spinlock);
@@ -179,19 +168,39 @@ mb_cache_shrink_fn(struct shrinker *shrink, struct shrink_control *sc)
struct mb_cache_entry, e_lru_list);
list_move_tail(&ce->e_lru_list, &free_list);
__mb_cache_entry_unhash(ce);
+ freed++;
+ }
+ spin_unlock(&mb_cache_spinlock);
+ list_for_each_entry_safe(entry, tmp, &free_list, e_lru_list) {
+ __mb_cache_entry_forget(entry, gfp_mask);
}
+ return freed;
+}
+
+static long
+mb_cache_shrink_count(
+ struct shrinker *shrink,
+ struct shrink_control *sc)
+{
+ struct mb_cache *cache;
+ long count = 0;
+
+ spin_lock(&mb_cache_spinlock);
list_for_each_entry(cache, &mb_cache_list, c_cache_list) {
mb_debug("cache %s (%d)", cache->c_name,
atomic_read(&cache->c_entry_count));
count += atomic_read(&cache->c_entry_count);
}
spin_unlock(&mb_cache_spinlock);
- list_for_each_entry_safe(entry, tmp, &free_list, e_lru_list) {
- __mb_cache_entry_forget(entry, gfp_mask);
- }
+
return vfs_pressure_ratio(count);
}
+static struct shrinker mb_cache_shrinker = {
+ .count_objects = mb_cache_shrink_count,
+ .scan_objects = mb_cache_shrink_scan,
+ .seeks = DEFAULT_SEEKS,
+};
/*
* mb_cache_create() create a new cache
diff --git a/fs/nfs/dir.c b/fs/nfs/dir.c
index 54d7c47..b355905 100644
--- a/fs/nfs/dir.c
+++ b/fs/nfs/dir.c
@@ -1958,17 +1958,20 @@ static void nfs_access_free_list(struct list_head *head)
}
}
-int nfs_access_cache_shrinker(struct shrinker *shrink,
- struct shrink_control *sc)
+long
+nfs_access_cache_scan(
+ struct shrinker *shrink,
+ struct shrink_control *sc)
{
LIST_HEAD(head);
struct nfs_inode *nfsi, *next;
struct nfs_access_entry *cache;
int nr_to_scan = sc->nr_to_scan;
gfp_t gfp_mask = sc->gfp_mask;
+ long freed = 0;
if ((gfp_mask & GFP_KERNEL) != GFP_KERNEL)
- return (nr_to_scan == 0) ? 0 : -1;
+ return -1;
spin_lock(&nfs_access_lru_lock);
list_for_each_entry_safe(nfsi, next, &nfs_access_lru_list, access_cache_inode_lru) {
@@ -1984,6 +1987,7 @@ int nfs_access_cache_shrinker(struct shrinker *shrink,
struct nfs_access_entry, lru);
list_move(&cache->lru, &head);
rb_erase(&cache->rb_node, &nfsi->access_cache);
+ freed++;
if (!list_empty(&nfsi->access_cache_entry_lru))
list_move_tail(&nfsi->access_cache_inode_lru,
&nfs_access_lru_list);
@@ -1998,6 +2002,14 @@ remove_lru_entry:
}
spin_unlock(&nfs_access_lru_lock);
nfs_access_free_list(&head);
+ return freed;
+}
+
+long
+nfs_access_cache_count(
+ struct shrinker *shrink,
+ struct shrink_control *sc)
+{
return vfs_pressure_ratio(atomic_long_read(&nfs_access_nr_entries));
}
diff --git a/fs/nfs/internal.h b/fs/nfs/internal.h
index 91e59a3..9651e20 100644
--- a/fs/nfs/internal.h
+++ b/fs/nfs/internal.h
@@ -269,7 +269,9 @@ extern struct nfs_client *nfs_init_client(struct nfs_client *clp,
const char *ip_addr, rpc_authflavor_t authflavour);
/* dir.c */
-extern int nfs_access_cache_shrinker(struct shrinker *shrink,
+extern long nfs_access_cache_count(struct shrinker *shrink,
+ struct shrink_control *sc);
+extern long nfs_access_cache_scan(struct shrinker *shrink,
struct shrink_control *sc);
struct dentry *nfs_lookup(struct inode *, struct dentry *, unsigned int);
int nfs_create(struct inode *, struct dentry *, umode_t, bool);
diff --git a/fs/nfs/super.c b/fs/nfs/super.c
index a366107..2fed70f 100644
--- a/fs/nfs/super.c
+++ b/fs/nfs/super.c
@@ -359,7 +359,8 @@ static void unregister_nfs4_fs(void)
#endif
static struct shrinker acl_shrinker = {
- .shrink = nfs_access_cache_shrinker,
+ .count_objects = nfs_access_cache_count,
+ .scan_objects = nfs_access_cache_scan,
.seeks = DEFAULT_SEEKS,
};
diff --git a/fs/nfsd/nfscache.c b/fs/nfsd/nfscache.c
index e76244e..5564c38 100644
--- a/fs/nfsd/nfscache.c
+++ b/fs/nfsd/nfscache.c
@@ -59,11 +59,14 @@ static unsigned int longest_chain_cachesize;
static int nfsd_cache_append(struct svc_rqst *rqstp, struct kvec *vec);
static void cache_cleaner_func(struct work_struct *unused);
-static int nfsd_reply_cache_shrink(struct shrinker *shrink,
- struct shrink_control *sc);
+static long nfsd_reply_cache_count(struct shrinker *shrink,
+ struct shrink_control *sc);
+static long nfsd_reply_cache_scan(struct shrinker *shrink,
+ struct shrink_control *sc);
static struct shrinker nfsd_reply_cache_shrinker = {
- .shrink = nfsd_reply_cache_shrink,
+ .scan_objects = nfsd_reply_cache_scan,
+ .count_objects = nfsd_reply_cache_count,
.seeks = 1,
};
@@ -232,16 +235,18 @@ nfsd_cache_entry_expired(struct svc_cacherep *rp)
* Walk the LRU list and prune off entries that are older than RC_EXPIRE.
* Also prune the oldest ones when the total exceeds the max number of entries.
*/
-static void
+static long
prune_cache_entries(void)
{
struct svc_cacherep *rp, *tmp;
+ long freed = 0;
list_for_each_entry_safe(rp, tmp, &lru_head, c_lru) {
if (!nfsd_cache_entry_expired(rp) &&
num_drc_entries <= max_drc_entries)
break;
nfsd_reply_cache_free_locked(rp);
+ freed++;
}
/*
@@ -254,6 +259,7 @@ prune_cache_entries(void)
cancel_delayed_work(&cache_cleaner);
else
mod_delayed_work(system_wq, &cache_cleaner, RC_EXPIRE);
+ return freed;
}
static void
@@ -264,20 +270,27 @@ cache_cleaner_func(struct work_struct *unused)
spin_unlock(&cache_lock);
}
-static int
-nfsd_reply_cache_shrink(struct shrinker *shrink, struct shrink_control *sc)
+static long
+nfsd_reply_cache_count(struct shrinker *shrink, struct shrink_control *sc)
{
- unsigned int num;
+ long num;
spin_lock(&cache_lock);
- if (sc->nr_to_scan)
- prune_cache_entries();
num = num_drc_entries;
spin_unlock(&cache_lock);
return num;
}
+static long
+nfsd_reply_cache_scan(struct shrinker *shrink, struct shrink_control *sc)
+{
+ long freed;
+ spin_lock(&cache_lock);
+ freed = prune_cache_entries();
+ spin_unlock(&cache_lock);
+ return freed;
+}
/*
* Walk an xdr_buf and get a CRC for at most the first RC_CSUMLEN bytes
*/
diff --git a/fs/quota/dquot.c b/fs/quota/dquot.c
index 762b09c..fd6b762 100644
--- a/fs/quota/dquot.c
+++ b/fs/quota/dquot.c
@@ -687,44 +687,42 @@ int dquot_quota_sync(struct super_block *sb, int type)
}
EXPORT_SYMBOL(dquot_quota_sync);
-/* Free unused dquots from cache */
-static void prune_dqcache(int count)
+static long
+dqcache_shrink_scan(
+ struct shrinker *shrink,
+ struct shrink_control *sc)
{
struct list_head *head;
struct dquot *dquot;
+ long freed = 0;
head = free_dquots.prev;
- while (head != &free_dquots && count) {
+ while (head != &free_dquots && sc->nr_to_scan) {
dquot = list_entry(head, struct dquot, dq_free);
remove_dquot_hash(dquot);
remove_free_dquot(dquot);
remove_inuse(dquot);
do_destroy_dquot(dquot);
- count--;
+ sc->nr_to_scan--;
+ freed++;
head = free_dquots.prev;
}
+ return freed;
}
-/*
- * This is called from kswapd when we think we need some
- * more memory
- */
-static int shrink_dqcache_memory(struct shrinker *shrink,
- struct shrink_control *sc)
-{
- int nr = sc->nr_to_scan;
+static long
+dqcache_shrink_count(
+ struct shrinker *shrink,
+ struct shrink_control *sc)
- if (nr) {
- spin_lock(&dq_list_lock);
- prune_dqcache(nr);
- spin_unlock(&dq_list_lock);
- }
+{
return vfs_pressure_ratio(
percpu_counter_read_positive(&dqstats.counter[DQST_FREE_DQUOTS]));
}
static struct shrinker dqcache_shrinker = {
- .shrink = shrink_dqcache_memory,
+ .count_objects = dqcache_shrink_count,
+ .scan_objects = dqcache_shrink_scan,
.seeks = DEFAULT_SEEKS,
};
diff --git a/fs/ubifs/shrinker.c b/fs/ubifs/shrinker.c
index 9e1d056..669d8c0 100644
--- a/fs/ubifs/shrinker.c
+++ b/fs/ubifs/shrinker.c
@@ -277,19 +277,23 @@ static int kick_a_thread(void)
return 0;
}
-int ubifs_shrinker(struct shrinker *shrink, struct shrink_control *sc)
+long ubifs_shrink_count(struct shrinker *shrink, struct shrink_control *sc)
+{
+ long clean_zn_cnt = atomic_long_read(&ubifs_clean_zn_cnt);
+
+ /*
+ * Due to the way UBIFS updates the clean znode counter it may
+ * temporarily be negative.
+ */
+ return clean_zn_cnt >= 0 ? clean_zn_cnt : 1;
+}
+
+long ubifs_shrink_scan(struct shrinker *shrink, struct shrink_control *sc)
{
int nr = sc->nr_to_scan;
int freed, contention = 0;
long clean_zn_cnt = atomic_long_read(&ubifs_clean_zn_cnt);
- if (nr == 0)
- /*
- * Due to the way UBIFS updates the clean znode counter it may
- * temporarily be negative.
- */
- return clean_zn_cnt >= 0 ? clean_zn_cnt : 1;
-
if (!clean_zn_cnt) {
/*
* No clean znodes, nothing to reap. All we can do in this case
diff --git a/fs/ubifs/super.c b/fs/ubifs/super.c
index f21acf0..ff357e0 100644
--- a/fs/ubifs/super.c
+++ b/fs/ubifs/super.c
@@ -49,7 +49,8 @@ struct kmem_cache *ubifs_inode_slab;
/* UBIFS TNC shrinker description */
static struct shrinker ubifs_shrinker_info = {
- .shrink = ubifs_shrinker,
+ .scan_objects = ubifs_shrink_scan,
+ .count_objects = ubifs_shrink_count,
.seeks = DEFAULT_SEEKS,
};
diff --git a/fs/ubifs/ubifs.h b/fs/ubifs/ubifs.h
index b2babce..bcdafcc 100644
--- a/fs/ubifs/ubifs.h
+++ b/fs/ubifs/ubifs.h
@@ -1624,7 +1624,8 @@ int ubifs_tnc_start_commit(struct ubifs_info *c, struct ubifs_zbranch *zroot);
int ubifs_tnc_end_commit(struct ubifs_info *c);
/* shrinker.c */
-int ubifs_shrinker(struct shrinker *shrink, struct shrink_control *sc);
+long ubifs_shrink_scan(struct shrinker *shrink, struct shrink_control *sc);
+long ubifs_shrink_count(struct shrinker *shrink, struct shrink_control *sc);
/* commit.c */
int ubifs_bg_thread(void *info);
--
1.8.1.4
^ permalink raw reply related [flat|nested] 151+ messages in thread* [PATCH v6 15/31] fs: convert fs shrinkers to new scan/count API
@ 2013-05-12 18:13 ` Glauber Costa
0 siblings, 0 replies; 151+ messages in thread
From: Glauber Costa @ 2013-05-12 18:13 UTC (permalink / raw)
To: linux-mm
Cc: cgroups, Andrew Morton, Greg Thelen, kamezawa.hiroyu,
Michal Hocko, Johannes Weiner, linux-fsdevel, Dave Chinner,
Dave Chinner, Glauber Costa, Steven Whitehouse, Artem Bityutskiy,
Adrian Hunter, Jan Kara
From: Dave Chinner <dchinner@redhat.com>
Convert the filesystem shrinkers to use the new API, and standardise
some of the behaviours of the shrinkers at the same time. For
example, nr_to_scan means the number of objects to scan, not the
number of objects to free.
I refactored the CIFS idmap shrinker a little - it really needs to
be broken up into a shrinker per tree and keep an item count with
the tree root so that we don't need to walk the tree every time the
shrinker needs to count the number of objects in the tree (i.e.
all the time under memory pressure).
[ glommer: fixes for ext4, ubifs, nfs, cifs and glock. Fixes are
needed mainly due to new code merged in the tree ]
Signed-off-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Glauber Costa <glommer@openvz.org>
Acked-by: Mel Gorman <mgorman@suse.de>
CC: Steven Whitehouse <swhiteho@redhat.com>
CC: Artem Bityutskiy <dedekind1@gmail.com>
CC: Adrian Hunter <adrian.hunter@intel.com>
CC: Jan Kara <jack@suse.cz>
---
fs/ext4/extents_status.c | 30 ++++++++++++++++------------
fs/gfs2/glock.c | 28 +++++++++++++++-----------
fs/gfs2/main.c | 3 ++-
fs/gfs2/quota.c | 12 +++++++-----
fs/gfs2/quota.h | 4 +++-
fs/mbcache.c | 51 ++++++++++++++++++++++++++++--------------------
fs/nfs/dir.c | 18 ++++++++++++++---
fs/nfs/internal.h | 4 +++-
fs/nfs/super.c | 3 ++-
fs/nfsd/nfscache.c | 31 ++++++++++++++++++++---------
fs/quota/dquot.c | 34 +++++++++++++++-----------------
fs/ubifs/shrinker.c | 20 +++++++++++--------
fs/ubifs/super.c | 3 ++-
fs/ubifs/ubifs.h | 3 ++-
14 files changed, 151 insertions(+), 93 deletions(-)
diff --git a/fs/ext4/extents_status.c b/fs/ext4/extents_status.c
index e6941e6..4bce4f0 100644
--- a/fs/ext4/extents_status.c
+++ b/fs/ext4/extents_status.c
@@ -878,20 +878,26 @@ int ext4_es_zeroout(struct inode *inode, struct ext4_extent *ex)
EXTENT_STATUS_WRITTEN);
}
-static int ext4_es_shrink(struct shrinker *shrink, struct shrink_control *sc)
+
+static long ext4_es_count(struct shrinker *shrink, struct shrink_control *sc)
+{
+ long nr;
+ struct ext4_sb_info *sbi = container_of(shrink,
+ struct ext4_sb_info, s_es_shrinker);
+
+ nr = percpu_counter_read_positive(&sbi->s_extent_cache_cnt);
+ trace_ext4_es_shrink_enter(sbi->s_sb, sc->nr_to_scan, nr);
+ return nr;
+}
+
+static long ext4_es_scan(struct shrinker *shrink, struct shrink_control *sc)
{
struct ext4_sb_info *sbi = container_of(shrink,
struct ext4_sb_info, s_es_shrinker);
struct ext4_inode_info *ei;
struct list_head *cur, *tmp, scanned;
int nr_to_scan = sc->nr_to_scan;
- int ret, nr_shrunk = 0;
-
- ret = percpu_counter_read_positive(&sbi->s_extent_cache_cnt);
- trace_ext4_es_shrink_enter(sbi->s_sb, nr_to_scan, ret);
-
- if (!nr_to_scan)
- return ret;
+ int ret = 0, nr_shrunk = 0;
INIT_LIST_HEAD(&scanned);
@@ -920,9 +926,8 @@ static int ext4_es_shrink(struct shrinker *shrink, struct shrink_control *sc)
list_splice_tail(&scanned, &sbi->s_es_lru);
spin_unlock(&sbi->s_es_lru_lock);
- ret = percpu_counter_read_positive(&sbi->s_extent_cache_cnt);
trace_ext4_es_shrink_exit(sbi->s_sb, nr_shrunk, ret);
- return ret;
+ return nr_shrunk;
}
void ext4_es_register_shrinker(struct super_block *sb)
@@ -932,7 +937,8 @@ void ext4_es_register_shrinker(struct super_block *sb)
sbi = EXT4_SB(sb);
INIT_LIST_HEAD(&sbi->s_es_lru);
spin_lock_init(&sbi->s_es_lru_lock);
- sbi->s_es_shrinker.shrink = ext4_es_shrink;
+ sbi->s_es_shrinker.scan_objects = ext4_es_scan;
+ sbi->s_es_shrinker.count_objects = ext4_es_count;
sbi->s_es_shrinker.seeks = DEFAULT_SEEKS;
register_shrinker(&sbi->s_es_shrinker);
}
@@ -973,7 +979,7 @@ static int __es_try_to_reclaim_extents(struct ext4_inode_info *ei,
struct ext4_es_tree *tree = &ei->i_es_tree;
struct rb_node *node;
struct extent_status *es;
- int nr_shrunk = 0;
+ long nr_shrunk = 0;
if (ei->i_es_lru_nr == 0)
return 0;
diff --git a/fs/gfs2/glock.c b/fs/gfs2/glock.c
index 3bd2748..4ddbccb 100644
--- a/fs/gfs2/glock.c
+++ b/fs/gfs2/glock.c
@@ -1428,21 +1428,22 @@ __acquires(&lru_lock)
* gfs2_dispose_glock_lru() above.
*/
-static void gfs2_scan_glock_lru(int nr)
+static long gfs2_scan_glock_lru(int nr)
{
struct gfs2_glock *gl;
LIST_HEAD(skipped);
LIST_HEAD(dispose);
+ long freed = 0;
spin_lock(&lru_lock);
- while(nr && !list_empty(&lru_list)) {
+ while ((nr-- >= 0) && !list_empty(&lru_list)) {
gl = list_entry(lru_list.next, struct gfs2_glock, gl_lru);
/* Test for being demotable */
if (!test_and_set_bit(GLF_LOCK, &gl->gl_flags)) {
list_move(&gl->gl_lru, &dispose);
atomic_dec(&lru_count);
- nr--;
+ freed++;
continue;
}
@@ -1452,23 +1453,28 @@ static void gfs2_scan_glock_lru(int nr)
if (!list_empty(&dispose))
gfs2_dispose_glock_lru(&dispose);
spin_unlock(&lru_lock);
+
+ return freed;
}
-static int gfs2_shrink_glock_memory(struct shrinker *shrink,
- struct shrink_control *sc)
+static long gfs2_glock_shrink_scan(struct shrinker *shrink,
+ struct shrink_control *sc)
{
- if (sc->nr_to_scan) {
- if (!(sc->gfp_mask & __GFP_FS))
- return -1;
- gfs2_scan_glock_lru(sc->nr_to_scan);
- }
+ if (!(sc->gfp_mask & __GFP_FS))
+ return -1;
+ return gfs2_scan_glock_lru(sc->nr_to_scan);
+}
+static long gfs2_glock_shrink_count(struct shrinker *shrink,
+ struct shrink_control *sc)
+{
return vfs_pressure_ratio(atomic_read(&lru_count));
}
static struct shrinker glock_shrinker = {
- .shrink = gfs2_shrink_glock_memory,
.seeks = DEFAULT_SEEKS,
+ .count_objects = gfs2_glock_shrink_count,
+ .scan_objects = gfs2_glock_shrink_scan,
};
/**
diff --git a/fs/gfs2/main.c b/fs/gfs2/main.c
index e04d0e0..a105d84 100644
--- a/fs/gfs2/main.c
+++ b/fs/gfs2/main.c
@@ -32,7 +32,8 @@
struct workqueue_struct *gfs2_control_wq;
static struct shrinker qd_shrinker = {
- .shrink = gfs2_shrink_qd_memory,
+ .count_objects = gfs2_qd_shrink_count,
+ .scan_objects = gfs2_qd_shrink_scan,
.seeks = DEFAULT_SEEKS,
};
diff --git a/fs/gfs2/quota.c b/fs/gfs2/quota.c
index 5c14206..77b82f6 100644
--- a/fs/gfs2/quota.c
+++ b/fs/gfs2/quota.c
@@ -75,14 +75,12 @@ static LIST_HEAD(qd_lru_list);
static atomic_t qd_lru_count = ATOMIC_INIT(0);
static DEFINE_SPINLOCK(qd_lru_lock);
-int gfs2_shrink_qd_memory(struct shrinker *shrink, struct shrink_control *sc)
+long gfs2_qd_shrink_scan(struct shrinker *shrink, struct shrink_control *sc)
{
struct gfs2_quota_data *qd;
struct gfs2_sbd *sdp;
int nr_to_scan = sc->nr_to_scan;
-
- if (nr_to_scan == 0)
- goto out;
+ long freed = 0;
if (!(sc->gfp_mask & __GFP_FS))
return -1;
@@ -110,10 +108,14 @@ int gfs2_shrink_qd_memory(struct shrinker *shrink, struct shrink_control *sc)
kmem_cache_free(gfs2_quotad_cachep, qd);
spin_lock(&qd_lru_lock);
nr_to_scan--;
+ freed++;
}
spin_unlock(&qd_lru_lock);
+ return freed;
+}
-out:
+long gfs2_qd_shrink_count(struct shrinker *shrink, struct shrink_control *sc)
+{
return vfs_pressure_ratio(atomic_read(&qd_lru_count));
}
diff --git a/fs/gfs2/quota.h b/fs/gfs2/quota.h
index 4f5e6e4..4f61708 100644
--- a/fs/gfs2/quota.h
+++ b/fs/gfs2/quota.h
@@ -53,7 +53,9 @@ static inline int gfs2_quota_lock_check(struct gfs2_inode *ip)
return ret;
}
-extern int gfs2_shrink_qd_memory(struct shrinker *shrink,
+extern long gfs2_qd_shrink_count(struct shrinker *shrink,
+ struct shrink_control *sc);
+extern long gfs2_qd_shrink_scan(struct shrinker *shrink,
struct shrink_control *sc);
extern const struct quotactl_ops gfs2_quotactl_ops;
diff --git a/fs/mbcache.c b/fs/mbcache.c
index 5eb0476..009a463 100644
--- a/fs/mbcache.c
+++ b/fs/mbcache.c
@@ -86,18 +86,6 @@ static LIST_HEAD(mb_cache_list);
static LIST_HEAD(mb_cache_lru_list);
static DEFINE_SPINLOCK(mb_cache_spinlock);
-/*
- * What the mbcache registers as to get shrunk dynamically.
- */
-
-static int mb_cache_shrink_fn(struct shrinker *shrink,
- struct shrink_control *sc);
-
-static struct shrinker mb_cache_shrinker = {
- .shrink = mb_cache_shrink_fn,
- .seeks = DEFAULT_SEEKS,
-};
-
static inline int
__mb_cache_entry_is_hashed(struct mb_cache_entry *ce)
{
@@ -151,7 +139,7 @@ forget:
/*
- * mb_cache_shrink_fn() memory pressure callback
+ * mb_cache_shrink_scan() memory pressure callback
*
* This function is called by the kernel memory management when memory
* gets low.
@@ -159,17 +147,18 @@ forget:
* @shrink: (ignored)
* @sc: shrink_control passed from reclaim
*
- * Returns the number of objects which are present in the cache.
+ * Returns the number of objects freed.
*/
-static int
-mb_cache_shrink_fn(struct shrinker *shrink, struct shrink_control *sc)
+static long
+mb_cache_shrink_scan(
+ struct shrinker *shrink,
+ struct shrink_control *sc)
{
LIST_HEAD(free_list);
- struct mb_cache *cache;
struct mb_cache_entry *entry, *tmp;
- int count = 0;
int nr_to_scan = sc->nr_to_scan;
gfp_t gfp_mask = sc->gfp_mask;
+ long freed = 0;
mb_debug("trying to free %d entries", nr_to_scan);
spin_lock(&mb_cache_spinlock);
@@ -179,19 +168,39 @@ mb_cache_shrink_fn(struct shrinker *shrink, struct shrink_control *sc)
struct mb_cache_entry, e_lru_list);
list_move_tail(&ce->e_lru_list, &free_list);
__mb_cache_entry_unhash(ce);
+ freed++;
+ }
+ spin_unlock(&mb_cache_spinlock);
+ list_for_each_entry_safe(entry, tmp, &free_list, e_lru_list) {
+ __mb_cache_entry_forget(entry, gfp_mask);
}
+ return freed;
+}
+
+static long
+mb_cache_shrink_count(
+ struct shrinker *shrink,
+ struct shrink_control *sc)
+{
+ struct mb_cache *cache;
+ long count = 0;
+
+ spin_lock(&mb_cache_spinlock);
list_for_each_entry(cache, &mb_cache_list, c_cache_list) {
mb_debug("cache %s (%d)", cache->c_name,
atomic_read(&cache->c_entry_count));
count += atomic_read(&cache->c_entry_count);
}
spin_unlock(&mb_cache_spinlock);
- list_for_each_entry_safe(entry, tmp, &free_list, e_lru_list) {
- __mb_cache_entry_forget(entry, gfp_mask);
- }
+
return vfs_pressure_ratio(count);
}
+static struct shrinker mb_cache_shrinker = {
+ .count_objects = mb_cache_shrink_count,
+ .scan_objects = mb_cache_shrink_scan,
+ .seeks = DEFAULT_SEEKS,
+};
/*
* mb_cache_create() create a new cache
diff --git a/fs/nfs/dir.c b/fs/nfs/dir.c
index 54d7c47..b355905 100644
--- a/fs/nfs/dir.c
+++ b/fs/nfs/dir.c
@@ -1958,17 +1958,20 @@ static void nfs_access_free_list(struct list_head *head)
}
}
-int nfs_access_cache_shrinker(struct shrinker *shrink,
- struct shrink_control *sc)
+long
+nfs_access_cache_scan(
+ struct shrinker *shrink,
+ struct shrink_control *sc)
{
LIST_HEAD(head);
struct nfs_inode *nfsi, *next;
struct nfs_access_entry *cache;
int nr_to_scan = sc->nr_to_scan;
gfp_t gfp_mask = sc->gfp_mask;
+ long freed = 0;
if ((gfp_mask & GFP_KERNEL) != GFP_KERNEL)
- return (nr_to_scan == 0) ? 0 : -1;
+ return -1;
spin_lock(&nfs_access_lru_lock);
list_for_each_entry_safe(nfsi, next, &nfs_access_lru_list, access_cache_inode_lru) {
@@ -1984,6 +1987,7 @@ int nfs_access_cache_shrinker(struct shrinker *shrink,
struct nfs_access_entry, lru);
list_move(&cache->lru, &head);
rb_erase(&cache->rb_node, &nfsi->access_cache);
+ freed++;
if (!list_empty(&nfsi->access_cache_entry_lru))
list_move_tail(&nfsi->access_cache_inode_lru,
&nfs_access_lru_list);
@@ -1998,6 +2002,14 @@ remove_lru_entry:
}
spin_unlock(&nfs_access_lru_lock);
nfs_access_free_list(&head);
+ return freed;
+}
+
+long
+nfs_access_cache_count(
+ struct shrinker *shrink,
+ struct shrink_control *sc)
+{
return vfs_pressure_ratio(atomic_long_read(&nfs_access_nr_entries));
}
diff --git a/fs/nfs/internal.h b/fs/nfs/internal.h
index 91e59a3..9651e20 100644
--- a/fs/nfs/internal.h
+++ b/fs/nfs/internal.h
@@ -269,7 +269,9 @@ extern struct nfs_client *nfs_init_client(struct nfs_client *clp,
const char *ip_addr, rpc_authflavor_t authflavour);
/* dir.c */
-extern int nfs_access_cache_shrinker(struct shrinker *shrink,
+extern long nfs_access_cache_count(struct shrinker *shrink,
+ struct shrink_control *sc);
+extern long nfs_access_cache_scan(struct shrinker *shrink,
struct shrink_control *sc);
struct dentry *nfs_lookup(struct inode *, struct dentry *, unsigned int);
int nfs_create(struct inode *, struct dentry *, umode_t, bool);
diff --git a/fs/nfs/super.c b/fs/nfs/super.c
index a366107..2fed70f 100644
--- a/fs/nfs/super.c
+++ b/fs/nfs/super.c
@@ -359,7 +359,8 @@ static void unregister_nfs4_fs(void)
#endif
static struct shrinker acl_shrinker = {
- .shrink = nfs_access_cache_shrinker,
+ .count_objects = nfs_access_cache_count,
+ .scan_objects = nfs_access_cache_scan,
.seeks = DEFAULT_SEEKS,
};
diff --git a/fs/nfsd/nfscache.c b/fs/nfsd/nfscache.c
index e76244e..5564c38 100644
--- a/fs/nfsd/nfscache.c
+++ b/fs/nfsd/nfscache.c
@@ -59,11 +59,14 @@ static unsigned int longest_chain_cachesize;
static int nfsd_cache_append(struct svc_rqst *rqstp, struct kvec *vec);
static void cache_cleaner_func(struct work_struct *unused);
-static int nfsd_reply_cache_shrink(struct shrinker *shrink,
- struct shrink_control *sc);
+static long nfsd_reply_cache_count(struct shrinker *shrink,
+ struct shrink_control *sc);
+static long nfsd_reply_cache_scan(struct shrinker *shrink,
+ struct shrink_control *sc);
static struct shrinker nfsd_reply_cache_shrinker = {
- .shrink = nfsd_reply_cache_shrink,
+ .scan_objects = nfsd_reply_cache_scan,
+ .count_objects = nfsd_reply_cache_count,
.seeks = 1,
};
@@ -232,16 +235,18 @@ nfsd_cache_entry_expired(struct svc_cacherep *rp)
* Walk the LRU list and prune off entries that are older than RC_EXPIRE.
* Also prune the oldest ones when the total exceeds the max number of entries.
*/
-static void
+static long
prune_cache_entries(void)
{
struct svc_cacherep *rp, *tmp;
+ long freed = 0;
list_for_each_entry_safe(rp, tmp, &lru_head, c_lru) {
if (!nfsd_cache_entry_expired(rp) &&
num_drc_entries <= max_drc_entries)
break;
nfsd_reply_cache_free_locked(rp);
+ freed++;
}
/*
@@ -254,6 +259,7 @@ prune_cache_entries(void)
cancel_delayed_work(&cache_cleaner);
else
mod_delayed_work(system_wq, &cache_cleaner, RC_EXPIRE);
+ return freed;
}
static void
@@ -264,20 +270,27 @@ cache_cleaner_func(struct work_struct *unused)
spin_unlock(&cache_lock);
}
-static int
-nfsd_reply_cache_shrink(struct shrinker *shrink, struct shrink_control *sc)
+static long
+nfsd_reply_cache_count(struct shrinker *shrink, struct shrink_control *sc)
{
- unsigned int num;
+ long num;
spin_lock(&cache_lock);
- if (sc->nr_to_scan)
- prune_cache_entries();
num = num_drc_entries;
spin_unlock(&cache_lock);
return num;
}
+static long
+nfsd_reply_cache_scan(struct shrinker *shrink, struct shrink_control *sc)
+{
+ long freed;
+ spin_lock(&cache_lock);
+ freed = prune_cache_entries();
+ spin_unlock(&cache_lock);
+ return freed;
+}
/*
* Walk an xdr_buf and get a CRC for at most the first RC_CSUMLEN bytes
*/
diff --git a/fs/quota/dquot.c b/fs/quota/dquot.c
index 762b09c..fd6b762 100644
--- a/fs/quota/dquot.c
+++ b/fs/quota/dquot.c
@@ -687,44 +687,42 @@ int dquot_quota_sync(struct super_block *sb, int type)
}
EXPORT_SYMBOL(dquot_quota_sync);
-/* Free unused dquots from cache */
-static void prune_dqcache(int count)
+static long
+dqcache_shrink_scan(
+ struct shrinker *shrink,
+ struct shrink_control *sc)
{
struct list_head *head;
struct dquot *dquot;
+ long freed = 0;
head = free_dquots.prev;
- while (head != &free_dquots && count) {
+ while (head != &free_dquots && sc->nr_to_scan) {
dquot = list_entry(head, struct dquot, dq_free);
remove_dquot_hash(dquot);
remove_free_dquot(dquot);
remove_inuse(dquot);
do_destroy_dquot(dquot);
- count--;
+ sc->nr_to_scan--;
+ freed++;
head = free_dquots.prev;
}
+ return freed;
}
-/*
- * This is called from kswapd when we think we need some
- * more memory
- */
-static int shrink_dqcache_memory(struct shrinker *shrink,
- struct shrink_control *sc)
-{
- int nr = sc->nr_to_scan;
+static long
+dqcache_shrink_count(
+ struct shrinker *shrink,
+ struct shrink_control *sc)
- if (nr) {
- spin_lock(&dq_list_lock);
- prune_dqcache(nr);
- spin_unlock(&dq_list_lock);
- }
+{
return vfs_pressure_ratio(
percpu_counter_read_positive(&dqstats.counter[DQST_FREE_DQUOTS]));
}
static struct shrinker dqcache_shrinker = {
- .shrink = shrink_dqcache_memory,
+ .count_objects = dqcache_shrink_count,
+ .scan_objects = dqcache_shrink_scan,
.seeks = DEFAULT_SEEKS,
};
diff --git a/fs/ubifs/shrinker.c b/fs/ubifs/shrinker.c
index 9e1d056..669d8c0 100644
--- a/fs/ubifs/shrinker.c
+++ b/fs/ubifs/shrinker.c
@@ -277,19 +277,23 @@ static int kick_a_thread(void)
return 0;
}
-int ubifs_shrinker(struct shrinker *shrink, struct shrink_control *sc)
+long ubifs_shrink_count(struct shrinker *shrink, struct shrink_control *sc)
+{
+ long clean_zn_cnt = atomic_long_read(&ubifs_clean_zn_cnt);
+
+ /*
+ * Due to the way UBIFS updates the clean znode counter it may
+ * temporarily be negative.
+ */
+ return clean_zn_cnt >= 0 ? clean_zn_cnt : 1;
+}
+
+long ubifs_shrink_scan(struct shrinker *shrink, struct shrink_control *sc)
{
int nr = sc->nr_to_scan;
int freed, contention = 0;
long clean_zn_cnt = atomic_long_read(&ubifs_clean_zn_cnt);
- if (nr == 0)
- /*
- * Due to the way UBIFS updates the clean znode counter it may
- * temporarily be negative.
- */
- return clean_zn_cnt >= 0 ? clean_zn_cnt : 1;
-
if (!clean_zn_cnt) {
/*
* No clean znodes, nothing to reap. All we can do in this case
diff --git a/fs/ubifs/super.c b/fs/ubifs/super.c
index f21acf0..ff357e0 100644
--- a/fs/ubifs/super.c
+++ b/fs/ubifs/super.c
@@ -49,7 +49,8 @@ struct kmem_cache *ubifs_inode_slab;
/* UBIFS TNC shrinker description */
static struct shrinker ubifs_shrinker_info = {
- .shrink = ubifs_shrinker,
+ .scan_objects = ubifs_shrink_scan,
+ .count_objects = ubifs_shrink_count,
.seeks = DEFAULT_SEEKS,
};
diff --git a/fs/ubifs/ubifs.h b/fs/ubifs/ubifs.h
index b2babce..bcdafcc 100644
--- a/fs/ubifs/ubifs.h
+++ b/fs/ubifs/ubifs.h
@@ -1624,7 +1624,8 @@ int ubifs_tnc_start_commit(struct ubifs_info *c, struct ubifs_zbranch *zroot);
int ubifs_tnc_end_commit(struct ubifs_info *c);
/* shrinker.c */
-int ubifs_shrinker(struct shrinker *shrink, struct shrink_control *sc);
+long ubifs_shrink_scan(struct shrinker *shrink, struct shrink_control *sc);
+long ubifs_shrink_count(struct shrinker *shrink, struct shrink_control *sc);
/* commit.c */
int ubifs_bg_thread(void *info);
--
1.8.1.4
^ permalink raw reply related [flat|nested] 151+ messages in thread* [PATCH v6 15/31] fs: convert fs shrinkers to new scan/count API
@ 2013-05-12 18:13 ` Glauber Costa
0 siblings, 0 replies; 151+ messages in thread
From: Glauber Costa @ 2013-05-12 18:13 UTC (permalink / raw)
To: linux-mm
Cc: cgroups, Andrew Morton, Greg Thelen, kamezawa.hiroyu,
Michal Hocko, Johannes Weiner, linux-fsdevel, Dave Chinner,
Dave Chinner, Glauber Costa, Steven Whitehouse, Artem Bityutskiy,
Adrian Hunter, Jan Kara
From: Dave Chinner <dchinner@redhat.com>
Convert the filesystem shrinkers to use the new API, and standardise
some of the behaviours of the shrinkers at the same time. For
example, nr_to_scan means the number of objects to scan, not the
number of objects to free.
I refactored the CIFS idmap shrinker a little - it really needs to
be broken up into a shrinker per tree and keep an item count with
the tree root so that we don't need to walk the tree every time the
shrinker needs to count the number of objects in the tree (i.e.
all the time under memory pressure).
[ glommer: fixes for ext4, ubifs, nfs, cifs and glock. Fixes are
needed mainly due to new code merged in the tree ]
Signed-off-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Glauber Costa <glommer@openvz.org>
Acked-by: Mel Gorman <mgorman@suse.de>
CC: Steven Whitehouse <swhiteho@redhat.com>
CC: Artem Bityutskiy <dedekind1@gmail.com>
CC: Adrian Hunter <adrian.hunter@intel.com>
CC: Jan Kara <jack@suse.cz>
---
fs/ext4/extents_status.c | 30 ++++++++++++++++------------
fs/gfs2/glock.c | 28 +++++++++++++++-----------
fs/gfs2/main.c | 3 ++-
fs/gfs2/quota.c | 12 +++++++-----
fs/gfs2/quota.h | 4 +++-
fs/mbcache.c | 51 ++++++++++++++++++++++++++++--------------------
fs/nfs/dir.c | 18 ++++++++++++++---
fs/nfs/internal.h | 4 +++-
fs/nfs/super.c | 3 ++-
fs/nfsd/nfscache.c | 31 ++++++++++++++++++++---------
fs/quota/dquot.c | 34 +++++++++++++++-----------------
fs/ubifs/shrinker.c | 20 +++++++++++--------
fs/ubifs/super.c | 3 ++-
fs/ubifs/ubifs.h | 3 ++-
14 files changed, 151 insertions(+), 93 deletions(-)
diff --git a/fs/ext4/extents_status.c b/fs/ext4/extents_status.c
index e6941e6..4bce4f0 100644
--- a/fs/ext4/extents_status.c
+++ b/fs/ext4/extents_status.c
@@ -878,20 +878,26 @@ int ext4_es_zeroout(struct inode *inode, struct ext4_extent *ex)
EXTENT_STATUS_WRITTEN);
}
-static int ext4_es_shrink(struct shrinker *shrink, struct shrink_control *sc)
+
+static long ext4_es_count(struct shrinker *shrink, struct shrink_control *sc)
+{
+ long nr;
+ struct ext4_sb_info *sbi = container_of(shrink,
+ struct ext4_sb_info, s_es_shrinker);
+
+ nr = percpu_counter_read_positive(&sbi->s_extent_cache_cnt);
+ trace_ext4_es_shrink_enter(sbi->s_sb, sc->nr_to_scan, nr);
+ return nr;
+}
+
+static long ext4_es_scan(struct shrinker *shrink, struct shrink_control *sc)
{
struct ext4_sb_info *sbi = container_of(shrink,
struct ext4_sb_info, s_es_shrinker);
struct ext4_inode_info *ei;
struct list_head *cur, *tmp, scanned;
int nr_to_scan = sc->nr_to_scan;
- int ret, nr_shrunk = 0;
-
- ret = percpu_counter_read_positive(&sbi->s_extent_cache_cnt);
- trace_ext4_es_shrink_enter(sbi->s_sb, nr_to_scan, ret);
-
- if (!nr_to_scan)
- return ret;
+ int ret = 0, nr_shrunk = 0;
INIT_LIST_HEAD(&scanned);
@@ -920,9 +926,8 @@ static int ext4_es_shrink(struct shrinker *shrink, struct shrink_control *sc)
list_splice_tail(&scanned, &sbi->s_es_lru);
spin_unlock(&sbi->s_es_lru_lock);
- ret = percpu_counter_read_positive(&sbi->s_extent_cache_cnt);
trace_ext4_es_shrink_exit(sbi->s_sb, nr_shrunk, ret);
- return ret;
+ return nr_shrunk;
}
void ext4_es_register_shrinker(struct super_block *sb)
@@ -932,7 +937,8 @@ void ext4_es_register_shrinker(struct super_block *sb)
sbi = EXT4_SB(sb);
INIT_LIST_HEAD(&sbi->s_es_lru);
spin_lock_init(&sbi->s_es_lru_lock);
- sbi->s_es_shrinker.shrink = ext4_es_shrink;
+ sbi->s_es_shrinker.scan_objects = ext4_es_scan;
+ sbi->s_es_shrinker.count_objects = ext4_es_count;
sbi->s_es_shrinker.seeks = DEFAULT_SEEKS;
register_shrinker(&sbi->s_es_shrinker);
}
@@ -973,7 +979,7 @@ static int __es_try_to_reclaim_extents(struct ext4_inode_info *ei,
struct ext4_es_tree *tree = &ei->i_es_tree;
struct rb_node *node;
struct extent_status *es;
- int nr_shrunk = 0;
+ long nr_shrunk = 0;
if (ei->i_es_lru_nr == 0)
return 0;
diff --git a/fs/gfs2/glock.c b/fs/gfs2/glock.c
index 3bd2748..4ddbccb 100644
--- a/fs/gfs2/glock.c
+++ b/fs/gfs2/glock.c
@@ -1428,21 +1428,22 @@ __acquires(&lru_lock)
* gfs2_dispose_glock_lru() above.
*/
-static void gfs2_scan_glock_lru(int nr)
+static long gfs2_scan_glock_lru(int nr)
{
struct gfs2_glock *gl;
LIST_HEAD(skipped);
LIST_HEAD(dispose);
+ long freed = 0;
spin_lock(&lru_lock);
- while(nr && !list_empty(&lru_list)) {
+ while ((nr-- >= 0) && !list_empty(&lru_list)) {
gl = list_entry(lru_list.next, struct gfs2_glock, gl_lru);
/* Test for being demotable */
if (!test_and_set_bit(GLF_LOCK, &gl->gl_flags)) {
list_move(&gl->gl_lru, &dispose);
atomic_dec(&lru_count);
- nr--;
+ freed++;
continue;
}
@@ -1452,23 +1453,28 @@ static void gfs2_scan_glock_lru(int nr)
if (!list_empty(&dispose))
gfs2_dispose_glock_lru(&dispose);
spin_unlock(&lru_lock);
+
+ return freed;
}
-static int gfs2_shrink_glock_memory(struct shrinker *shrink,
- struct shrink_control *sc)
+static long gfs2_glock_shrink_scan(struct shrinker *shrink,
+ struct shrink_control *sc)
{
- if (sc->nr_to_scan) {
- if (!(sc->gfp_mask & __GFP_FS))
- return -1;
- gfs2_scan_glock_lru(sc->nr_to_scan);
- }
+ if (!(sc->gfp_mask & __GFP_FS))
+ return -1;
+ return gfs2_scan_glock_lru(sc->nr_to_scan);
+}
+static long gfs2_glock_shrink_count(struct shrinker *shrink,
+ struct shrink_control *sc)
+{
return vfs_pressure_ratio(atomic_read(&lru_count));
}
static struct shrinker glock_shrinker = {
- .shrink = gfs2_shrink_glock_memory,
.seeks = DEFAULT_SEEKS,
+ .count_objects = gfs2_glock_shrink_count,
+ .scan_objects = gfs2_glock_shrink_scan,
};
/**
diff --git a/fs/gfs2/main.c b/fs/gfs2/main.c
index e04d0e0..a105d84 100644
--- a/fs/gfs2/main.c
+++ b/fs/gfs2/main.c
@@ -32,7 +32,8 @@
struct workqueue_struct *gfs2_control_wq;
static struct shrinker qd_shrinker = {
- .shrink = gfs2_shrink_qd_memory,
+ .count_objects = gfs2_qd_shrink_count,
+ .scan_objects = gfs2_qd_shrink_scan,
.seeks = DEFAULT_SEEKS,
};
diff --git a/fs/gfs2/quota.c b/fs/gfs2/quota.c
index 5c14206..77b82f6 100644
--- a/fs/gfs2/quota.c
+++ b/fs/gfs2/quota.c
@@ -75,14 +75,12 @@ static LIST_HEAD(qd_lru_list);
static atomic_t qd_lru_count = ATOMIC_INIT(0);
static DEFINE_SPINLOCK(qd_lru_lock);
-int gfs2_shrink_qd_memory(struct shrinker *shrink, struct shrink_control *sc)
+long gfs2_qd_shrink_scan(struct shrinker *shrink, struct shrink_control *sc)
{
struct gfs2_quota_data *qd;
struct gfs2_sbd *sdp;
int nr_to_scan = sc->nr_to_scan;
-
- if (nr_to_scan == 0)
- goto out;
+ long freed = 0;
if (!(sc->gfp_mask & __GFP_FS))
return -1;
@@ -110,10 +108,14 @@ int gfs2_shrink_qd_memory(struct shrinker *shrink, struct shrink_control *sc)
kmem_cache_free(gfs2_quotad_cachep, qd);
spin_lock(&qd_lru_lock);
nr_to_scan--;
+ freed++;
}
spin_unlock(&qd_lru_lock);
+ return freed;
+}
-out:
+long gfs2_qd_shrink_count(struct shrinker *shrink, struct shrink_control *sc)
+{
return vfs_pressure_ratio(atomic_read(&qd_lru_count));
}
diff --git a/fs/gfs2/quota.h b/fs/gfs2/quota.h
index 4f5e6e4..4f61708 100644
--- a/fs/gfs2/quota.h
+++ b/fs/gfs2/quota.h
@@ -53,7 +53,9 @@ static inline int gfs2_quota_lock_check(struct gfs2_inode *ip)
return ret;
}
-extern int gfs2_shrink_qd_memory(struct shrinker *shrink,
+extern long gfs2_qd_shrink_count(struct shrinker *shrink,
+ struct shrink_control *sc);
+extern long gfs2_qd_shrink_scan(struct shrinker *shrink,
struct shrink_control *sc);
extern const struct quotactl_ops gfs2_quotactl_ops;
diff --git a/fs/mbcache.c b/fs/mbcache.c
index 5eb0476..009a463 100644
--- a/fs/mbcache.c
+++ b/fs/mbcache.c
@@ -86,18 +86,6 @@ static LIST_HEAD(mb_cache_list);
static LIST_HEAD(mb_cache_lru_list);
static DEFINE_SPINLOCK(mb_cache_spinlock);
-/*
- * What the mbcache registers as to get shrunk dynamically.
- */
-
-static int mb_cache_shrink_fn(struct shrinker *shrink,
- struct shrink_control *sc);
-
-static struct shrinker mb_cache_shrinker = {
- .shrink = mb_cache_shrink_fn,
- .seeks = DEFAULT_SEEKS,
-};
-
static inline int
__mb_cache_entry_is_hashed(struct mb_cache_entry *ce)
{
@@ -151,7 +139,7 @@ forget:
/*
- * mb_cache_shrink_fn() memory pressure callback
+ * mb_cache_shrink_scan() memory pressure callback
*
* This function is called by the kernel memory management when memory
* gets low.
@@ -159,17 +147,18 @@ forget:
* @shrink: (ignored)
* @sc: shrink_control passed from reclaim
*
- * Returns the number of objects which are present in the cache.
+ * Returns the number of objects freed.
*/
-static int
-mb_cache_shrink_fn(struct shrinker *shrink, struct shrink_control *sc)
+static long
+mb_cache_shrink_scan(
+ struct shrinker *shrink,
+ struct shrink_control *sc)
{
LIST_HEAD(free_list);
- struct mb_cache *cache;
struct mb_cache_entry *entry, *tmp;
- int count = 0;
int nr_to_scan = sc->nr_to_scan;
gfp_t gfp_mask = sc->gfp_mask;
+ long freed = 0;
mb_debug("trying to free %d entries", nr_to_scan);
spin_lock(&mb_cache_spinlock);
@@ -179,19 +168,39 @@ mb_cache_shrink_fn(struct shrinker *shrink, struct shrink_control *sc)
struct mb_cache_entry, e_lru_list);
list_move_tail(&ce->e_lru_list, &free_list);
__mb_cache_entry_unhash(ce);
+ freed++;
+ }
+ spin_unlock(&mb_cache_spinlock);
+ list_for_each_entry_safe(entry, tmp, &free_list, e_lru_list) {
+ __mb_cache_entry_forget(entry, gfp_mask);
}
+ return freed;
+}
+
+static long
+mb_cache_shrink_count(
+ struct shrinker *shrink,
+ struct shrink_control *sc)
+{
+ struct mb_cache *cache;
+ long count = 0;
+
+ spin_lock(&mb_cache_spinlock);
list_for_each_entry(cache, &mb_cache_list, c_cache_list) {
mb_debug("cache %s (%d)", cache->c_name,
atomic_read(&cache->c_entry_count));
count += atomic_read(&cache->c_entry_count);
}
spin_unlock(&mb_cache_spinlock);
- list_for_each_entry_safe(entry, tmp, &free_list, e_lru_list) {
- __mb_cache_entry_forget(entry, gfp_mask);
- }
+
return vfs_pressure_ratio(count);
}
+static struct shrinker mb_cache_shrinker = {
+ .count_objects = mb_cache_shrink_count,
+ .scan_objects = mb_cache_shrink_scan,
+ .seeks = DEFAULT_SEEKS,
+};
/*
* mb_cache_create() create a new cache
diff --git a/fs/nfs/dir.c b/fs/nfs/dir.c
index 54d7c47..b355905 100644
--- a/fs/nfs/dir.c
+++ b/fs/nfs/dir.c
@@ -1958,17 +1958,20 @@ static void nfs_access_free_list(struct list_head *head)
}
}
-int nfs_access_cache_shrinker(struct shrinker *shrink,
- struct shrink_control *sc)
+long
+nfs_access_cache_scan(
+ struct shrinker *shrink,
+ struct shrink_control *sc)
{
LIST_HEAD(head);
struct nfs_inode *nfsi, *next;
struct nfs_access_entry *cache;
int nr_to_scan = sc->nr_to_scan;
gfp_t gfp_mask = sc->gfp_mask;
+ long freed = 0;
if ((gfp_mask & GFP_KERNEL) != GFP_KERNEL)
- return (nr_to_scan == 0) ? 0 : -1;
+ return -1;
spin_lock(&nfs_access_lru_lock);
list_for_each_entry_safe(nfsi, next, &nfs_access_lru_list, access_cache_inode_lru) {
@@ -1984,6 +1987,7 @@ int nfs_access_cache_shrinker(struct shrinker *shrink,
struct nfs_access_entry, lru);
list_move(&cache->lru, &head);
rb_erase(&cache->rb_node, &nfsi->access_cache);
+ freed++;
if (!list_empty(&nfsi->access_cache_entry_lru))
list_move_tail(&nfsi->access_cache_inode_lru,
&nfs_access_lru_list);
@@ -1998,6 +2002,14 @@ remove_lru_entry:
}
spin_unlock(&nfs_access_lru_lock);
nfs_access_free_list(&head);
+ return freed;
+}
+
+long
+nfs_access_cache_count(
+ struct shrinker *shrink,
+ struct shrink_control *sc)
+{
return vfs_pressure_ratio(atomic_long_read(&nfs_access_nr_entries));
}
diff --git a/fs/nfs/internal.h b/fs/nfs/internal.h
index 91e59a3..9651e20 100644
--- a/fs/nfs/internal.h
+++ b/fs/nfs/internal.h
@@ -269,7 +269,9 @@ extern struct nfs_client *nfs_init_client(struct nfs_client *clp,
const char *ip_addr, rpc_authflavor_t authflavour);
/* dir.c */
-extern int nfs_access_cache_shrinker(struct shrinker *shrink,
+extern long nfs_access_cache_count(struct shrinker *shrink,
+ struct shrink_control *sc);
+extern long nfs_access_cache_scan(struct shrinker *shrink,
struct shrink_control *sc);
struct dentry *nfs_lookup(struct inode *, struct dentry *, unsigned int);
int nfs_create(struct inode *, struct dentry *, umode_t, bool);
diff --git a/fs/nfs/super.c b/fs/nfs/super.c
index a366107..2fed70f 100644
--- a/fs/nfs/super.c
+++ b/fs/nfs/super.c
@@ -359,7 +359,8 @@ static void unregister_nfs4_fs(void)
#endif
static struct shrinker acl_shrinker = {
- .shrink = nfs_access_cache_shrinker,
+ .count_objects = nfs_access_cache_count,
+ .scan_objects = nfs_access_cache_scan,
.seeks = DEFAULT_SEEKS,
};
diff --git a/fs/nfsd/nfscache.c b/fs/nfsd/nfscache.c
index e76244e..5564c38 100644
--- a/fs/nfsd/nfscache.c
+++ b/fs/nfsd/nfscache.c
@@ -59,11 +59,14 @@ static unsigned int longest_chain_cachesize;
static int nfsd_cache_append(struct svc_rqst *rqstp, struct kvec *vec);
static void cache_cleaner_func(struct work_struct *unused);
-static int nfsd_reply_cache_shrink(struct shrinker *shrink,
- struct shrink_control *sc);
+static long nfsd_reply_cache_count(struct shrinker *shrink,
+ struct shrink_control *sc);
+static long nfsd_reply_cache_scan(struct shrinker *shrink,
+ struct shrink_control *sc);
static struct shrinker nfsd_reply_cache_shrinker = {
- .shrink = nfsd_reply_cache_shrink,
+ .scan_objects = nfsd_reply_cache_scan,
+ .count_objects = nfsd_reply_cache_count,
.seeks = 1,
};
@@ -232,16 +235,18 @@ nfsd_cache_entry_expired(struct svc_cacherep *rp)
* Walk the LRU list and prune off entries that are older than RC_EXPIRE.
* Also prune the oldest ones when the total exceeds the max number of entries.
*/
-static void
+static long
prune_cache_entries(void)
{
struct svc_cacherep *rp, *tmp;
+ long freed = 0;
list_for_each_entry_safe(rp, tmp, &lru_head, c_lru) {
if (!nfsd_cache_entry_expired(rp) &&
num_drc_entries <= max_drc_entries)
break;
nfsd_reply_cache_free_locked(rp);
+ freed++;
}
/*
@@ -254,6 +259,7 @@ prune_cache_entries(void)
cancel_delayed_work(&cache_cleaner);
else
mod_delayed_work(system_wq, &cache_cleaner, RC_EXPIRE);
+ return freed;
}
static void
@@ -264,20 +270,27 @@ cache_cleaner_func(struct work_struct *unused)
spin_unlock(&cache_lock);
}
-static int
-nfsd_reply_cache_shrink(struct shrinker *shrink, struct shrink_control *sc)
+static long
+nfsd_reply_cache_count(struct shrinker *shrink, struct shrink_control *sc)
{
- unsigned int num;
+ long num;
spin_lock(&cache_lock);
- if (sc->nr_to_scan)
- prune_cache_entries();
num = num_drc_entries;
spin_unlock(&cache_lock);
return num;
}
+static long
+nfsd_reply_cache_scan(struct shrinker *shrink, struct shrink_control *sc)
+{
+ long freed;
+ spin_lock(&cache_lock);
+ freed = prune_cache_entries();
+ spin_unlock(&cache_lock);
+ return freed;
+}
/*
* Walk an xdr_buf and get a CRC for at most the first RC_CSUMLEN bytes
*/
diff --git a/fs/quota/dquot.c b/fs/quota/dquot.c
index 762b09c..fd6b762 100644
--- a/fs/quota/dquot.c
+++ b/fs/quota/dquot.c
@@ -687,44 +687,42 @@ int dquot_quota_sync(struct super_block *sb, int type)
}
EXPORT_SYMBOL(dquot_quota_sync);
-/* Free unused dquots from cache */
-static void prune_dqcache(int count)
+static long
+dqcache_shrink_scan(
+ struct shrinker *shrink,
+ struct shrink_control *sc)
{
struct list_head *head;
struct dquot *dquot;
+ long freed = 0;
head = free_dquots.prev;
- while (head != &free_dquots && count) {
+ while (head != &free_dquots && sc->nr_to_scan) {
dquot = list_entry(head, struct dquot, dq_free);
remove_dquot_hash(dquot);
remove_free_dquot(dquot);
remove_inuse(dquot);
do_destroy_dquot(dquot);
- count--;
+ sc->nr_to_scan--;
+ freed++;
head = free_dquots.prev;
}
+ return freed;
}
-/*
- * This is called from kswapd when we think we need some
- * more memory
- */
-static int shrink_dqcache_memory(struct shrinker *shrink,
- struct shrink_control *sc)
-{
- int nr = sc->nr_to_scan;
+static long
+dqcache_shrink_count(
+ struct shrinker *shrink,
+ struct shrink_control *sc)
- if (nr) {
- spin_lock(&dq_list_lock);
- prune_dqcache(nr);
- spin_unlock(&dq_list_lock);
- }
+{
return vfs_pressure_ratio(
percpu_counter_read_positive(&dqstats.counter[DQST_FREE_DQUOTS]));
}
static struct shrinker dqcache_shrinker = {
- .shrink = shrink_dqcache_memory,
+ .count_objects = dqcache_shrink_count,
+ .scan_objects = dqcache_shrink_scan,
.seeks = DEFAULT_SEEKS,
};
diff --git a/fs/ubifs/shrinker.c b/fs/ubifs/shrinker.c
index 9e1d056..669d8c0 100644
--- a/fs/ubifs/shrinker.c
+++ b/fs/ubifs/shrinker.c
@@ -277,19 +277,23 @@ static int kick_a_thread(void)
return 0;
}
-int ubifs_shrinker(struct shrinker *shrink, struct shrink_control *sc)
+long ubifs_shrink_count(struct shrinker *shrink, struct shrink_control *sc)
+{
+ long clean_zn_cnt = atomic_long_read(&ubifs_clean_zn_cnt);
+
+ /*
+ * Due to the way UBIFS updates the clean znode counter it may
+ * temporarily be negative.
+ */
+ return clean_zn_cnt >= 0 ? clean_zn_cnt : 1;
+}
+
+long ubifs_shrink_scan(struct shrinker *shrink, struct shrink_control *sc)
{
int nr = sc->nr_to_scan;
int freed, contention = 0;
long clean_zn_cnt = atomic_long_read(&ubifs_clean_zn_cnt);
- if (nr == 0)
- /*
- * Due to the way UBIFS updates the clean znode counter it may
- * temporarily be negative.
- */
- return clean_zn_cnt >= 0 ? clean_zn_cnt : 1;
-
if (!clean_zn_cnt) {
/*
* No clean znodes, nothing to reap. All we can do in this case
diff --git a/fs/ubifs/super.c b/fs/ubifs/super.c
index f21acf0..ff357e0 100644
--- a/fs/ubifs/super.c
+++ b/fs/ubifs/super.c
@@ -49,7 +49,8 @@ struct kmem_cache *ubifs_inode_slab;
/* UBIFS TNC shrinker description */
static struct shrinker ubifs_shrinker_info = {
- .shrink = ubifs_shrinker,
+ .scan_objects = ubifs_shrink_scan,
+ .count_objects = ubifs_shrink_count,
.seeks = DEFAULT_SEEKS,
};
diff --git a/fs/ubifs/ubifs.h b/fs/ubifs/ubifs.h
index b2babce..bcdafcc 100644
--- a/fs/ubifs/ubifs.h
+++ b/fs/ubifs/ubifs.h
@@ -1624,7 +1624,8 @@ int ubifs_tnc_start_commit(struct ubifs_info *c, struct ubifs_zbranch *zroot);
int ubifs_tnc_end_commit(struct ubifs_info *c);
/* shrinker.c */
-int ubifs_shrinker(struct shrinker *shrink, struct shrink_control *sc);
+long ubifs_shrink_scan(struct shrinker *shrink, struct shrink_control *sc);
+long ubifs_shrink_count(struct shrinker *shrink, struct shrink_control *sc);
/* commit.c */
int ubifs_bg_thread(void *info);
--
1.8.1.4
--
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^ permalink raw reply related [flat|nested] 151+ messages in thread* Re: [PATCH v6 15/31] fs: convert fs shrinkers to new scan/count API
2013-05-12 18:13 ` Glauber Costa
(?)
(?)
@ 2013-05-13 6:12 ` Artem Bityutskiy
[not found] ` <1368425530.3208.13.camel-Bxnoe/o8FG+Ef9UqXRslZEEOCMrvLtNR@public.gmane.org>
-1 siblings, 1 reply; 151+ messages in thread
From: Artem Bityutskiy @ 2013-05-13 6:12 UTC (permalink / raw)
To: Glauber Costa
Cc: linux-mm, cgroups, Andrew Morton, Greg Thelen, kamezawa.hiroyu,
Michal Hocko, Johannes Weiner, linux-fsdevel, Dave Chinner,
Dave Chinner, Steven Whitehouse, Adrian Hunter, Jan Kara
On Sun, 2013-05-12 at 22:13 +0400, Glauber Costa wrote:
> From: Dave Chinner <dchinner@redhat.com>
>
> Convert the filesystem shrinkers to use the new API, and standardise
> some of the behaviours of the shrinkers at the same time. For
> example, nr_to_scan means the number of objects to scan, not the
> number of objects to free.
>
> I refactored the CIFS idmap shrinker a little - it really needs to
> be broken up into a shrinker per tree and keep an item count with
> the tree root so that we don't need to walk the tree every time the
> shrinker needs to count the number of objects in the tree (i.e.
> all the time under memory pressure).
UBIFS part looks OK.
--
Best Regards,
Artem Bityutskiy
--
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^ permalink raw reply [flat|nested] 151+ messages in thread* Re: [PATCH v6 15/31] fs: convert fs shrinkers to new scan/count API
2013-05-12 18:13 ` Glauber Costa
` (2 preceding siblings ...)
(?)
@ 2013-05-13 10:36 ` Jan Kara
-1 siblings, 0 replies; 151+ messages in thread
From: Jan Kara @ 2013-05-13 10:36 UTC (permalink / raw)
To: Glauber Costa
Cc: linux-mm, cgroups, Andrew Morton, Greg Thelen, kamezawa.hiroyu,
Michal Hocko, Johannes Weiner, linux-fsdevel, Dave Chinner,
Dave Chinner, Steven Whitehouse, Artem Bityutskiy, Adrian Hunter,
Jan Kara
On Sun 12-05-13 22:13:36, Glauber Costa wrote:
> From: Dave Chinner <dchinner@redhat.com>
>
> Convert the filesystem shrinkers to use the new API, and standardise
> some of the behaviours of the shrinkers at the same time. For
> example, nr_to_scan means the number of objects to scan, not the
> number of objects to free.
>
> I refactored the CIFS idmap shrinker a little - it really needs to
> be broken up into a shrinker per tree and keep an item count with
> the tree root so that we don't need to walk the tree every time the
> shrinker needs to count the number of objects in the tree (i.e.
> all the time under memory pressure).
>
> [ glommer: fixes for ext4, ubifs, nfs, cifs and glock. Fixes are
> needed mainly due to new code merged in the tree ]
> Signed-off-by: Dave Chinner <dchinner@redhat.com>
> Signed-off-by: Glauber Costa <glommer@openvz.org>
> Acked-by: Mel Gorman <mgorman@suse.de>
> CC: Steven Whitehouse <swhiteho@redhat.com>
> CC: Artem Bityutskiy <dedekind1@gmail.com>
> CC: Adrian Hunter <adrian.hunter@intel.com>
> CC: Jan Kara <jack@suse.cz>
Acked-by: Jan Kara <jack@suse.cz>
for ext4, quota, and mbcache parts...
Honza
> ---
> fs/ext4/extents_status.c | 30 ++++++++++++++++------------
> fs/gfs2/glock.c | 28 +++++++++++++++-----------
> fs/gfs2/main.c | 3 ++-
> fs/gfs2/quota.c | 12 +++++++-----
> fs/gfs2/quota.h | 4 +++-
> fs/mbcache.c | 51 ++++++++++++++++++++++++++++--------------------
> fs/nfs/dir.c | 18 ++++++++++++++---
> fs/nfs/internal.h | 4 +++-
> fs/nfs/super.c | 3 ++-
> fs/nfsd/nfscache.c | 31 ++++++++++++++++++++---------
> fs/quota/dquot.c | 34 +++++++++++++++-----------------
> fs/ubifs/shrinker.c | 20 +++++++++++--------
> fs/ubifs/super.c | 3 ++-
> fs/ubifs/ubifs.h | 3 ++-
> 14 files changed, 151 insertions(+), 93 deletions(-)
>
> diff --git a/fs/ext4/extents_status.c b/fs/ext4/extents_status.c
> index e6941e6..4bce4f0 100644
> --- a/fs/ext4/extents_status.c
> +++ b/fs/ext4/extents_status.c
> @@ -878,20 +878,26 @@ int ext4_es_zeroout(struct inode *inode, struct ext4_extent *ex)
> EXTENT_STATUS_WRITTEN);
> }
>
> -static int ext4_es_shrink(struct shrinker *shrink, struct shrink_control *sc)
> +
> +static long ext4_es_count(struct shrinker *shrink, struct shrink_control *sc)
> +{
> + long nr;
> + struct ext4_sb_info *sbi = container_of(shrink,
> + struct ext4_sb_info, s_es_shrinker);
> +
> + nr = percpu_counter_read_positive(&sbi->s_extent_cache_cnt);
> + trace_ext4_es_shrink_enter(sbi->s_sb, sc->nr_to_scan, nr);
> + return nr;
> +}
> +
> +static long ext4_es_scan(struct shrinker *shrink, struct shrink_control *sc)
> {
> struct ext4_sb_info *sbi = container_of(shrink,
> struct ext4_sb_info, s_es_shrinker);
> struct ext4_inode_info *ei;
> struct list_head *cur, *tmp, scanned;
> int nr_to_scan = sc->nr_to_scan;
> - int ret, nr_shrunk = 0;
> -
> - ret = percpu_counter_read_positive(&sbi->s_extent_cache_cnt);
> - trace_ext4_es_shrink_enter(sbi->s_sb, nr_to_scan, ret);
> -
> - if (!nr_to_scan)
> - return ret;
> + int ret = 0, nr_shrunk = 0;
>
> INIT_LIST_HEAD(&scanned);
>
> @@ -920,9 +926,8 @@ static int ext4_es_shrink(struct shrinker *shrink, struct shrink_control *sc)
> list_splice_tail(&scanned, &sbi->s_es_lru);
> spin_unlock(&sbi->s_es_lru_lock);
>
> - ret = percpu_counter_read_positive(&sbi->s_extent_cache_cnt);
> trace_ext4_es_shrink_exit(sbi->s_sb, nr_shrunk, ret);
> - return ret;
> + return nr_shrunk;
> }
>
> void ext4_es_register_shrinker(struct super_block *sb)
> @@ -932,7 +937,8 @@ void ext4_es_register_shrinker(struct super_block *sb)
> sbi = EXT4_SB(sb);
> INIT_LIST_HEAD(&sbi->s_es_lru);
> spin_lock_init(&sbi->s_es_lru_lock);
> - sbi->s_es_shrinker.shrink = ext4_es_shrink;
> + sbi->s_es_shrinker.scan_objects = ext4_es_scan;
> + sbi->s_es_shrinker.count_objects = ext4_es_count;
> sbi->s_es_shrinker.seeks = DEFAULT_SEEKS;
> register_shrinker(&sbi->s_es_shrinker);
> }
> @@ -973,7 +979,7 @@ static int __es_try_to_reclaim_extents(struct ext4_inode_info *ei,
> struct ext4_es_tree *tree = &ei->i_es_tree;
> struct rb_node *node;
> struct extent_status *es;
> - int nr_shrunk = 0;
> + long nr_shrunk = 0;
>
> if (ei->i_es_lru_nr == 0)
> return 0;
> diff --git a/fs/gfs2/glock.c b/fs/gfs2/glock.c
> index 3bd2748..4ddbccb 100644
> --- a/fs/gfs2/glock.c
> +++ b/fs/gfs2/glock.c
> @@ -1428,21 +1428,22 @@ __acquires(&lru_lock)
> * gfs2_dispose_glock_lru() above.
> */
>
> -static void gfs2_scan_glock_lru(int nr)
> +static long gfs2_scan_glock_lru(int nr)
> {
> struct gfs2_glock *gl;
> LIST_HEAD(skipped);
> LIST_HEAD(dispose);
> + long freed = 0;
>
> spin_lock(&lru_lock);
> - while(nr && !list_empty(&lru_list)) {
> + while ((nr-- >= 0) && !list_empty(&lru_list)) {
> gl = list_entry(lru_list.next, struct gfs2_glock, gl_lru);
>
> /* Test for being demotable */
> if (!test_and_set_bit(GLF_LOCK, &gl->gl_flags)) {
> list_move(&gl->gl_lru, &dispose);
> atomic_dec(&lru_count);
> - nr--;
> + freed++;
> continue;
> }
>
> @@ -1452,23 +1453,28 @@ static void gfs2_scan_glock_lru(int nr)
> if (!list_empty(&dispose))
> gfs2_dispose_glock_lru(&dispose);
> spin_unlock(&lru_lock);
> +
> + return freed;
> }
>
> -static int gfs2_shrink_glock_memory(struct shrinker *shrink,
> - struct shrink_control *sc)
> +static long gfs2_glock_shrink_scan(struct shrinker *shrink,
> + struct shrink_control *sc)
> {
> - if (sc->nr_to_scan) {
> - if (!(sc->gfp_mask & __GFP_FS))
> - return -1;
> - gfs2_scan_glock_lru(sc->nr_to_scan);
> - }
> + if (!(sc->gfp_mask & __GFP_FS))
> + return -1;
> + return gfs2_scan_glock_lru(sc->nr_to_scan);
> +}
>
> +static long gfs2_glock_shrink_count(struct shrinker *shrink,
> + struct shrink_control *sc)
> +{
> return vfs_pressure_ratio(atomic_read(&lru_count));
> }
>
> static struct shrinker glock_shrinker = {
> - .shrink = gfs2_shrink_glock_memory,
> .seeks = DEFAULT_SEEKS,
> + .count_objects = gfs2_glock_shrink_count,
> + .scan_objects = gfs2_glock_shrink_scan,
> };
>
> /**
> diff --git a/fs/gfs2/main.c b/fs/gfs2/main.c
> index e04d0e0..a105d84 100644
> --- a/fs/gfs2/main.c
> +++ b/fs/gfs2/main.c
> @@ -32,7 +32,8 @@
> struct workqueue_struct *gfs2_control_wq;
>
> static struct shrinker qd_shrinker = {
> - .shrink = gfs2_shrink_qd_memory,
> + .count_objects = gfs2_qd_shrink_count,
> + .scan_objects = gfs2_qd_shrink_scan,
> .seeks = DEFAULT_SEEKS,
> };
>
> diff --git a/fs/gfs2/quota.c b/fs/gfs2/quota.c
> index 5c14206..77b82f6 100644
> --- a/fs/gfs2/quota.c
> +++ b/fs/gfs2/quota.c
> @@ -75,14 +75,12 @@ static LIST_HEAD(qd_lru_list);
> static atomic_t qd_lru_count = ATOMIC_INIT(0);
> static DEFINE_SPINLOCK(qd_lru_lock);
>
> -int gfs2_shrink_qd_memory(struct shrinker *shrink, struct shrink_control *sc)
> +long gfs2_qd_shrink_scan(struct shrinker *shrink, struct shrink_control *sc)
> {
> struct gfs2_quota_data *qd;
> struct gfs2_sbd *sdp;
> int nr_to_scan = sc->nr_to_scan;
> -
> - if (nr_to_scan == 0)
> - goto out;
> + long freed = 0;
>
> if (!(sc->gfp_mask & __GFP_FS))
> return -1;
> @@ -110,10 +108,14 @@ int gfs2_shrink_qd_memory(struct shrinker *shrink, struct shrink_control *sc)
> kmem_cache_free(gfs2_quotad_cachep, qd);
> spin_lock(&qd_lru_lock);
> nr_to_scan--;
> + freed++;
> }
> spin_unlock(&qd_lru_lock);
> + return freed;
> +}
>
> -out:
> +long gfs2_qd_shrink_count(struct shrinker *shrink, struct shrink_control *sc)
> +{
> return vfs_pressure_ratio(atomic_read(&qd_lru_count));
> }
>
> diff --git a/fs/gfs2/quota.h b/fs/gfs2/quota.h
> index 4f5e6e4..4f61708 100644
> --- a/fs/gfs2/quota.h
> +++ b/fs/gfs2/quota.h
> @@ -53,7 +53,9 @@ static inline int gfs2_quota_lock_check(struct gfs2_inode *ip)
> return ret;
> }
>
> -extern int gfs2_shrink_qd_memory(struct shrinker *shrink,
> +extern long gfs2_qd_shrink_count(struct shrinker *shrink,
> + struct shrink_control *sc);
> +extern long gfs2_qd_shrink_scan(struct shrinker *shrink,
> struct shrink_control *sc);
> extern const struct quotactl_ops gfs2_quotactl_ops;
>
> diff --git a/fs/mbcache.c b/fs/mbcache.c
> index 5eb0476..009a463 100644
> --- a/fs/mbcache.c
> +++ b/fs/mbcache.c
> @@ -86,18 +86,6 @@ static LIST_HEAD(mb_cache_list);
> static LIST_HEAD(mb_cache_lru_list);
> static DEFINE_SPINLOCK(mb_cache_spinlock);
>
> -/*
> - * What the mbcache registers as to get shrunk dynamically.
> - */
> -
> -static int mb_cache_shrink_fn(struct shrinker *shrink,
> - struct shrink_control *sc);
> -
> -static struct shrinker mb_cache_shrinker = {
> - .shrink = mb_cache_shrink_fn,
> - .seeks = DEFAULT_SEEKS,
> -};
> -
> static inline int
> __mb_cache_entry_is_hashed(struct mb_cache_entry *ce)
> {
> @@ -151,7 +139,7 @@ forget:
>
>
> /*
> - * mb_cache_shrink_fn() memory pressure callback
> + * mb_cache_shrink_scan() memory pressure callback
> *
> * This function is called by the kernel memory management when memory
> * gets low.
> @@ -159,17 +147,18 @@ forget:
> * @shrink: (ignored)
> * @sc: shrink_control passed from reclaim
> *
> - * Returns the number of objects which are present in the cache.
> + * Returns the number of objects freed.
> */
> -static int
> -mb_cache_shrink_fn(struct shrinker *shrink, struct shrink_control *sc)
> +static long
> +mb_cache_shrink_scan(
> + struct shrinker *shrink,
> + struct shrink_control *sc)
> {
> LIST_HEAD(free_list);
> - struct mb_cache *cache;
> struct mb_cache_entry *entry, *tmp;
> - int count = 0;
> int nr_to_scan = sc->nr_to_scan;
> gfp_t gfp_mask = sc->gfp_mask;
> + long freed = 0;
>
> mb_debug("trying to free %d entries", nr_to_scan);
> spin_lock(&mb_cache_spinlock);
> @@ -179,19 +168,39 @@ mb_cache_shrink_fn(struct shrinker *shrink, struct shrink_control *sc)
> struct mb_cache_entry, e_lru_list);
> list_move_tail(&ce->e_lru_list, &free_list);
> __mb_cache_entry_unhash(ce);
> + freed++;
> + }
> + spin_unlock(&mb_cache_spinlock);
> + list_for_each_entry_safe(entry, tmp, &free_list, e_lru_list) {
> + __mb_cache_entry_forget(entry, gfp_mask);
> }
> + return freed;
> +}
> +
> +static long
> +mb_cache_shrink_count(
> + struct shrinker *shrink,
> + struct shrink_control *sc)
> +{
> + struct mb_cache *cache;
> + long count = 0;
> +
> + spin_lock(&mb_cache_spinlock);
> list_for_each_entry(cache, &mb_cache_list, c_cache_list) {
> mb_debug("cache %s (%d)", cache->c_name,
> atomic_read(&cache->c_entry_count));
> count += atomic_read(&cache->c_entry_count);
> }
> spin_unlock(&mb_cache_spinlock);
> - list_for_each_entry_safe(entry, tmp, &free_list, e_lru_list) {
> - __mb_cache_entry_forget(entry, gfp_mask);
> - }
> +
> return vfs_pressure_ratio(count);
> }
>
> +static struct shrinker mb_cache_shrinker = {
> + .count_objects = mb_cache_shrink_count,
> + .scan_objects = mb_cache_shrink_scan,
> + .seeks = DEFAULT_SEEKS,
> +};
>
> /*
> * mb_cache_create() create a new cache
> diff --git a/fs/nfs/dir.c b/fs/nfs/dir.c
> index 54d7c47..b355905 100644
> --- a/fs/nfs/dir.c
> +++ b/fs/nfs/dir.c
> @@ -1958,17 +1958,20 @@ static void nfs_access_free_list(struct list_head *head)
> }
> }
>
> -int nfs_access_cache_shrinker(struct shrinker *shrink,
> - struct shrink_control *sc)
> +long
> +nfs_access_cache_scan(
> + struct shrinker *shrink,
> + struct shrink_control *sc)
> {
> LIST_HEAD(head);
> struct nfs_inode *nfsi, *next;
> struct nfs_access_entry *cache;
> int nr_to_scan = sc->nr_to_scan;
> gfp_t gfp_mask = sc->gfp_mask;
> + long freed = 0;
>
> if ((gfp_mask & GFP_KERNEL) != GFP_KERNEL)
> - return (nr_to_scan == 0) ? 0 : -1;
> + return -1;
>
> spin_lock(&nfs_access_lru_lock);
> list_for_each_entry_safe(nfsi, next, &nfs_access_lru_list, access_cache_inode_lru) {
> @@ -1984,6 +1987,7 @@ int nfs_access_cache_shrinker(struct shrinker *shrink,
> struct nfs_access_entry, lru);
> list_move(&cache->lru, &head);
> rb_erase(&cache->rb_node, &nfsi->access_cache);
> + freed++;
> if (!list_empty(&nfsi->access_cache_entry_lru))
> list_move_tail(&nfsi->access_cache_inode_lru,
> &nfs_access_lru_list);
> @@ -1998,6 +2002,14 @@ remove_lru_entry:
> }
> spin_unlock(&nfs_access_lru_lock);
> nfs_access_free_list(&head);
> + return freed;
> +}
> +
> +long
> +nfs_access_cache_count(
> + struct shrinker *shrink,
> + struct shrink_control *sc)
> +{
> return vfs_pressure_ratio(atomic_long_read(&nfs_access_nr_entries));
> }
>
> diff --git a/fs/nfs/internal.h b/fs/nfs/internal.h
> index 91e59a3..9651e20 100644
> --- a/fs/nfs/internal.h
> +++ b/fs/nfs/internal.h
> @@ -269,7 +269,9 @@ extern struct nfs_client *nfs_init_client(struct nfs_client *clp,
> const char *ip_addr, rpc_authflavor_t authflavour);
>
> /* dir.c */
> -extern int nfs_access_cache_shrinker(struct shrinker *shrink,
> +extern long nfs_access_cache_count(struct shrinker *shrink,
> + struct shrink_control *sc);
> +extern long nfs_access_cache_scan(struct shrinker *shrink,
> struct shrink_control *sc);
> struct dentry *nfs_lookup(struct inode *, struct dentry *, unsigned int);
> int nfs_create(struct inode *, struct dentry *, umode_t, bool);
> diff --git a/fs/nfs/super.c b/fs/nfs/super.c
> index a366107..2fed70f 100644
> --- a/fs/nfs/super.c
> +++ b/fs/nfs/super.c
> @@ -359,7 +359,8 @@ static void unregister_nfs4_fs(void)
> #endif
>
> static struct shrinker acl_shrinker = {
> - .shrink = nfs_access_cache_shrinker,
> + .count_objects = nfs_access_cache_count,
> + .scan_objects = nfs_access_cache_scan,
> .seeks = DEFAULT_SEEKS,
> };
>
> diff --git a/fs/nfsd/nfscache.c b/fs/nfsd/nfscache.c
> index e76244e..5564c38 100644
> --- a/fs/nfsd/nfscache.c
> +++ b/fs/nfsd/nfscache.c
> @@ -59,11 +59,14 @@ static unsigned int longest_chain_cachesize;
>
> static int nfsd_cache_append(struct svc_rqst *rqstp, struct kvec *vec);
> static void cache_cleaner_func(struct work_struct *unused);
> -static int nfsd_reply_cache_shrink(struct shrinker *shrink,
> - struct shrink_control *sc);
> +static long nfsd_reply_cache_count(struct shrinker *shrink,
> + struct shrink_control *sc);
> +static long nfsd_reply_cache_scan(struct shrinker *shrink,
> + struct shrink_control *sc);
>
> static struct shrinker nfsd_reply_cache_shrinker = {
> - .shrink = nfsd_reply_cache_shrink,
> + .scan_objects = nfsd_reply_cache_scan,
> + .count_objects = nfsd_reply_cache_count,
> .seeks = 1,
> };
>
> @@ -232,16 +235,18 @@ nfsd_cache_entry_expired(struct svc_cacherep *rp)
> * Walk the LRU list and prune off entries that are older than RC_EXPIRE.
> * Also prune the oldest ones when the total exceeds the max number of entries.
> */
> -static void
> +static long
> prune_cache_entries(void)
> {
> struct svc_cacherep *rp, *tmp;
> + long freed = 0;
>
> list_for_each_entry_safe(rp, tmp, &lru_head, c_lru) {
> if (!nfsd_cache_entry_expired(rp) &&
> num_drc_entries <= max_drc_entries)
> break;
> nfsd_reply_cache_free_locked(rp);
> + freed++;
> }
>
> /*
> @@ -254,6 +259,7 @@ prune_cache_entries(void)
> cancel_delayed_work(&cache_cleaner);
> else
> mod_delayed_work(system_wq, &cache_cleaner, RC_EXPIRE);
> + return freed;
> }
>
> static void
> @@ -264,20 +270,27 @@ cache_cleaner_func(struct work_struct *unused)
> spin_unlock(&cache_lock);
> }
>
> -static int
> -nfsd_reply_cache_shrink(struct shrinker *shrink, struct shrink_control *sc)
> +static long
> +nfsd_reply_cache_count(struct shrinker *shrink, struct shrink_control *sc)
> {
> - unsigned int num;
> + long num;
>
> spin_lock(&cache_lock);
> - if (sc->nr_to_scan)
> - prune_cache_entries();
> num = num_drc_entries;
> spin_unlock(&cache_lock);
>
> return num;
> }
>
> +static long
> +nfsd_reply_cache_scan(struct shrinker *shrink, struct shrink_control *sc)
> +{
> + long freed;
> + spin_lock(&cache_lock);
> + freed = prune_cache_entries();
> + spin_unlock(&cache_lock);
> + return freed;
> +}
> /*
> * Walk an xdr_buf and get a CRC for at most the first RC_CSUMLEN bytes
> */
> diff --git a/fs/quota/dquot.c b/fs/quota/dquot.c
> index 762b09c..fd6b762 100644
> --- a/fs/quota/dquot.c
> +++ b/fs/quota/dquot.c
> @@ -687,44 +687,42 @@ int dquot_quota_sync(struct super_block *sb, int type)
> }
> EXPORT_SYMBOL(dquot_quota_sync);
>
> -/* Free unused dquots from cache */
> -static void prune_dqcache(int count)
> +static long
> +dqcache_shrink_scan(
> + struct shrinker *shrink,
> + struct shrink_control *sc)
> {
> struct list_head *head;
> struct dquot *dquot;
> + long freed = 0;
>
> head = free_dquots.prev;
> - while (head != &free_dquots && count) {
> + while (head != &free_dquots && sc->nr_to_scan) {
> dquot = list_entry(head, struct dquot, dq_free);
> remove_dquot_hash(dquot);
> remove_free_dquot(dquot);
> remove_inuse(dquot);
> do_destroy_dquot(dquot);
> - count--;
> + sc->nr_to_scan--;
> + freed++;
> head = free_dquots.prev;
> }
> + return freed;
> }
>
> -/*
> - * This is called from kswapd when we think we need some
> - * more memory
> - */
> -static int shrink_dqcache_memory(struct shrinker *shrink,
> - struct shrink_control *sc)
> -{
> - int nr = sc->nr_to_scan;
> +static long
> +dqcache_shrink_count(
> + struct shrinker *shrink,
> + struct shrink_control *sc)
>
> - if (nr) {
> - spin_lock(&dq_list_lock);
> - prune_dqcache(nr);
> - spin_unlock(&dq_list_lock);
> - }
> +{
> return vfs_pressure_ratio(
> percpu_counter_read_positive(&dqstats.counter[DQST_FREE_DQUOTS]));
> }
>
> static struct shrinker dqcache_shrinker = {
> - .shrink = shrink_dqcache_memory,
> + .count_objects = dqcache_shrink_count,
> + .scan_objects = dqcache_shrink_scan,
> .seeks = DEFAULT_SEEKS,
> };
>
> diff --git a/fs/ubifs/shrinker.c b/fs/ubifs/shrinker.c
> index 9e1d056..669d8c0 100644
> --- a/fs/ubifs/shrinker.c
> +++ b/fs/ubifs/shrinker.c
> @@ -277,19 +277,23 @@ static int kick_a_thread(void)
> return 0;
> }
>
> -int ubifs_shrinker(struct shrinker *shrink, struct shrink_control *sc)
> +long ubifs_shrink_count(struct shrinker *shrink, struct shrink_control *sc)
> +{
> + long clean_zn_cnt = atomic_long_read(&ubifs_clean_zn_cnt);
> +
> + /*
> + * Due to the way UBIFS updates the clean znode counter it may
> + * temporarily be negative.
> + */
> + return clean_zn_cnt >= 0 ? clean_zn_cnt : 1;
> +}
> +
> +long ubifs_shrink_scan(struct shrinker *shrink, struct shrink_control *sc)
> {
> int nr = sc->nr_to_scan;
> int freed, contention = 0;
> long clean_zn_cnt = atomic_long_read(&ubifs_clean_zn_cnt);
>
> - if (nr == 0)
> - /*
> - * Due to the way UBIFS updates the clean znode counter it may
> - * temporarily be negative.
> - */
> - return clean_zn_cnt >= 0 ? clean_zn_cnt : 1;
> -
> if (!clean_zn_cnt) {
> /*
> * No clean znodes, nothing to reap. All we can do in this case
> diff --git a/fs/ubifs/super.c b/fs/ubifs/super.c
> index f21acf0..ff357e0 100644
> --- a/fs/ubifs/super.c
> +++ b/fs/ubifs/super.c
> @@ -49,7 +49,8 @@ struct kmem_cache *ubifs_inode_slab;
>
> /* UBIFS TNC shrinker description */
> static struct shrinker ubifs_shrinker_info = {
> - .shrink = ubifs_shrinker,
> + .scan_objects = ubifs_shrink_scan,
> + .count_objects = ubifs_shrink_count,
> .seeks = DEFAULT_SEEKS,
> };
>
> diff --git a/fs/ubifs/ubifs.h b/fs/ubifs/ubifs.h
> index b2babce..bcdafcc 100644
> --- a/fs/ubifs/ubifs.h
> +++ b/fs/ubifs/ubifs.h
> @@ -1624,7 +1624,8 @@ int ubifs_tnc_start_commit(struct ubifs_info *c, struct ubifs_zbranch *zroot);
> int ubifs_tnc_end_commit(struct ubifs_info *c);
>
> /* shrinker.c */
> -int ubifs_shrinker(struct shrinker *shrink, struct shrink_control *sc);
> +long ubifs_shrink_scan(struct shrinker *shrink, struct shrink_control *sc);
> +long ubifs_shrink_count(struct shrinker *shrink, struct shrink_control *sc);
>
> /* commit.c */
> int ubifs_bg_thread(void *info);
> --
> 1.8.1.4
>
--
Jan Kara <jack@suse.cz>
SUSE Labs, CR
--
To unsubscribe, send a message with 'unsubscribe linux-mm' in
the body to majordomo@kvack.org. For more info on Linux MM,
see: http://www.linux-mm.org/ .
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^ permalink raw reply [flat|nested] 151+ messages in thread
* [PATCH v6 16/31] drivers: convert shrinkers to new count/scan API
2013-05-12 18:13 ` Glauber Costa
(?)
@ 2013-05-12 18:13 ` Glauber Costa
-1 siblings, 0 replies; 151+ messages in thread
From: Glauber Costa @ 2013-05-12 18:13 UTC (permalink / raw)
To: linux-mm
Cc: cgroups, Andrew Morton, Greg Thelen, kamezawa.hiroyu,
Michal Hocko, Johannes Weiner, linux-fsdevel, Dave Chinner,
Dave Chinner, Glauber Costa, Daniel Vetter, Kent Overstreet,
Arve Hjønnevåg, John Stultz, David Rientjes,
Jerome Glisse, Thomas Hellstrom
From: Dave Chinner <dchinner@redhat.com>
Convert the driver shrinkers to the new API. Most changes are
compile tested only because I either don't have the hardware or it's
staging stuff.
FWIW, the md and android code is pretty good, but the rest of it
makes me want to claw my eyes out. The amount of broken code I just
encountered is mind boggling. I've added comments explaining what
is broken, but I fear that some of the code would be best dealt with
by being dragged behind the bike shed, burying in mud up to it's
neck and then run over repeatedly with a blunt lawn mower.
Special mention goes to the zcache/zcache2 drivers. They can't
co-exist in the build at the same time, they are under different
menu options in menuconfig, they only show up when you've got the
right set of mm subsystem options configured and so even compile
testing is an exercise in pulling teeth. And that doesn't even take
into account the horrible, broken code...
[ glommer: fixes for i915, android lowmem, zcache, bcache ]
Signed-off-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Glauber Costa <glommer@openvz.org>
Acked-by: Mel Gorman <mgorman@suse.de>
CC: Daniel Vetter <daniel.vetter@ffwll.ch>
CC: Kent Overstreet <koverstreet@google.com>
CC: Arve Hjønnevåg <arve@android.com>
CC: John Stultz <john.stultz@linaro.org>
CC: David Rientjes <rientjes@google.com>
CC: Jerome Glisse <jglisse@redhat.com>
CC: Thomas Hellstrom <thellstrom@vmware.com>
---
drivers/gpu/drm/i915/i915_dma.c | 4 +-
drivers/gpu/drm/i915/i915_gem.c | 67 ++++++++++++++++++++++---------
drivers/gpu/drm/ttm/ttm_page_alloc.c | 48 ++++++++++++++--------
drivers/gpu/drm/ttm/ttm_page_alloc_dma.c | 55 ++++++++++++++++---------
drivers/md/bcache/btree.c | 43 ++++++++++----------
drivers/md/bcache/sysfs.c | 2 +-
drivers/md/dm-bufio.c | 65 +++++++++++++++++++-----------
drivers/staging/android/ashmem.c | 45 ++++++++++++++-------
drivers/staging/android/lowmemorykiller.c | 40 ++++++++++--------
drivers/staging/zcache/zcache-main.c | 29 ++++++++-----
10 files changed, 256 insertions(+), 142 deletions(-)
diff --git a/drivers/gpu/drm/i915/i915_dma.c b/drivers/gpu/drm/i915/i915_dma.c
index 3b315ba..cfe3373 100644
--- a/drivers/gpu/drm/i915/i915_dma.c
+++ b/drivers/gpu/drm/i915/i915_dma.c
@@ -1669,7 +1669,7 @@ int i915_driver_load(struct drm_device *dev, unsigned long flags)
return 0;
out_gem_unload:
- if (dev_priv->mm.inactive_shrinker.shrink)
+ if (dev_priv->mm.inactive_shrinker.scan_objects)
unregister_shrinker(&dev_priv->mm.inactive_shrinker);
if (dev->pdev->msi_enabled)
@@ -1705,7 +1705,7 @@ int i915_driver_unload(struct drm_device *dev)
i915_teardown_sysfs(dev);
- if (dev_priv->mm.inactive_shrinker.shrink)
+ if (dev_priv->mm.inactive_shrinker.scan_objects)
unregister_shrinker(&dev_priv->mm.inactive_shrinker);
mutex_lock(&dev->struct_mutex);
diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c
index 6165535..6b17122 100644
--- a/drivers/gpu/drm/i915/i915_gem.c
+++ b/drivers/gpu/drm/i915/i915_gem.c
@@ -53,10 +53,12 @@ static void i915_gem_object_update_fence(struct drm_i915_gem_object *obj,
struct drm_i915_fence_reg *fence,
bool enable);
-static int i915_gem_inactive_shrink(struct shrinker *shrinker,
+static long i915_gem_inactive_count(struct shrinker *shrinker,
struct shrink_control *sc);
+static long i915_gem_inactive_scan(struct shrinker *shrinker,
+ struct shrink_control *sc);
static long i915_gem_purge(struct drm_i915_private *dev_priv, long target);
-static void i915_gem_shrink_all(struct drm_i915_private *dev_priv);
+static long i915_gem_shrink_all(struct drm_i915_private *dev_priv);
static void i915_gem_object_truncate(struct drm_i915_gem_object *obj);
static inline void i915_gem_object_fence_lost(struct drm_i915_gem_object *obj)
@@ -1729,15 +1731,20 @@ i915_gem_purge(struct drm_i915_private *dev_priv, long target)
return __i915_gem_shrink(dev_priv, target, true);
}
-static void
+static long
i915_gem_shrink_all(struct drm_i915_private *dev_priv)
{
struct drm_i915_gem_object *obj, *next;
+ long freed = 0;
i915_gem_evict_everything(dev_priv->dev);
- list_for_each_entry_safe(obj, next, &dev_priv->mm.unbound_list, gtt_list)
+ list_for_each_entry_safe(obj, next, &dev_priv->mm.unbound_list, gtt_list) {
+ if (obj->pages_pin_count == 0)
+ freed += obj->base.size >> PAGE_SHIFT;
i915_gem_object_put_pages(obj);
+ }
+ return freed;
}
static int
@@ -4203,7 +4210,8 @@ i915_gem_load(struct drm_device *dev)
dev_priv->mm.interruptible = true;
- dev_priv->mm.inactive_shrinker.shrink = i915_gem_inactive_shrink;
+ dev_priv->mm.inactive_shrinker.scan_objects = i915_gem_inactive_scan;
+ dev_priv->mm.inactive_shrinker.count_objects = i915_gem_inactive_count;
dev_priv->mm.inactive_shrinker.seeks = DEFAULT_SEEKS;
register_shrinker(&dev_priv->mm.inactive_shrinker);
}
@@ -4426,8 +4434,8 @@ static bool mutex_is_locked_by(struct mutex *mutex, struct task_struct *task)
#endif
}
-static int
-i915_gem_inactive_shrink(struct shrinker *shrinker, struct shrink_control *sc)
+static long
+i915_gem_inactive_count(struct shrinker *shrinker, struct shrink_control *sc)
{
struct drm_i915_private *dev_priv =
container_of(shrinker,
@@ -4435,9 +4443,8 @@ i915_gem_inactive_shrink(struct shrinker *shrinker, struct shrink_control *sc)
mm.inactive_shrinker);
struct drm_device *dev = dev_priv->dev;
struct drm_i915_gem_object *obj;
- int nr_to_scan = sc->nr_to_scan;
bool unlock = true;
- int cnt;
+ long cnt;
if (!mutex_trylock(&dev->struct_mutex)) {
if (!mutex_is_locked_by(&dev->struct_mutex, current))
@@ -4449,15 +4456,6 @@ i915_gem_inactive_shrink(struct shrinker *shrinker, struct shrink_control *sc)
unlock = false;
}
- if (nr_to_scan) {
- nr_to_scan -= i915_gem_purge(dev_priv, nr_to_scan);
- if (nr_to_scan > 0)
- nr_to_scan -= __i915_gem_shrink(dev_priv, nr_to_scan,
- false);
- if (nr_to_scan > 0)
- i915_gem_shrink_all(dev_priv);
- }
-
cnt = 0;
list_for_each_entry(obj, &dev_priv->mm.unbound_list, gtt_list)
if (obj->pages_pin_count == 0)
@@ -4470,3 +4468,36 @@ i915_gem_inactive_shrink(struct shrinker *shrinker, struct shrink_control *sc)
mutex_unlock(&dev->struct_mutex);
return cnt;
}
+static long
+i915_gem_inactive_scan(struct shrinker *shrinker, struct shrink_control *sc)
+{
+ struct drm_i915_private *dev_priv =
+ container_of(shrinker,
+ struct drm_i915_private,
+ mm.inactive_shrinker);
+ struct drm_device *dev = dev_priv->dev;
+ int nr_to_scan = sc->nr_to_scan;
+ long freed;
+ bool unlock = true;
+
+ if (!mutex_trylock(&dev->struct_mutex)) {
+ if (!mutex_is_locked_by(&dev->struct_mutex, current))
+ return 0;
+
+ if (dev_priv->mm.shrinker_no_lock_stealing)
+ return 0;
+
+ unlock = false;
+ }
+
+ freed = i915_gem_purge(dev_priv, nr_to_scan);
+ if (freed < nr_to_scan)
+ freed += __i915_gem_shrink(dev_priv, nr_to_scan,
+ false);
+ if (freed < nr_to_scan)
+ freed += i915_gem_shrink_all(dev_priv);
+
+ if (unlock)
+ mutex_unlock(&dev->struct_mutex);
+ return freed;
+}
diff --git a/drivers/gpu/drm/ttm/ttm_page_alloc.c b/drivers/gpu/drm/ttm/ttm_page_alloc.c
index bd2a3b4..83058a2 100644
--- a/drivers/gpu/drm/ttm/ttm_page_alloc.c
+++ b/drivers/gpu/drm/ttm/ttm_page_alloc.c
@@ -377,28 +377,28 @@ out:
return nr_free;
}
-/* Get good estimation how many pages are free in pools */
-static int ttm_pool_get_num_unused_pages(void)
-{
- unsigned i;
- int total = 0;
- for (i = 0; i < NUM_POOLS; ++i)
- total += _manager->pools[i].npages;
-
- return total;
-}
-
/**
* Callback for mm to request pool to reduce number of page held.
+ *
+ * XXX: (dchinner) Deadlock warning!
+ *
+ * ttm_page_pool_free() does memory allocation using GFP_KERNEL. that means
+ * this can deadlock when called a sc->gfp_mask that is not equal to
+ * GFP_KERNEL.
+ *
+ * This code is crying out for a shrinker per pool....
*/
-static int ttm_pool_mm_shrink(struct shrinker *shrink,
- struct shrink_control *sc)
+static long
+ttm_pool_shrink_scan(
+ struct shrinker *shrink,
+ struct shrink_control *sc)
{
static atomic_t start_pool = ATOMIC_INIT(0);
unsigned i;
unsigned pool_offset = atomic_add_return(1, &start_pool);
struct ttm_page_pool *pool;
int shrink_pages = sc->nr_to_scan;
+ long freed = 0;
pool_offset = pool_offset % NUM_POOLS;
/* select start pool in round robin fashion */
@@ -408,14 +408,30 @@ static int ttm_pool_mm_shrink(struct shrinker *shrink,
break;
pool = &_manager->pools[(i + pool_offset)%NUM_POOLS];
shrink_pages = ttm_page_pool_free(pool, nr_free);
+ freed += nr_free - shrink_pages;
}
- /* return estimated number of unused pages in pool */
- return ttm_pool_get_num_unused_pages();
+ return freed;
+}
+
+
+static long
+ttm_pool_shrink_count(
+ struct shrinker *shrink,
+ struct shrink_control *sc)
+{
+ unsigned i;
+ long count = 0;
+
+ for (i = 0; i < NUM_POOLS; ++i)
+ count += _manager->pools[i].npages;
+
+ return count;
}
static void ttm_pool_mm_shrink_init(struct ttm_pool_manager *manager)
{
- manager->mm_shrink.shrink = &ttm_pool_mm_shrink;
+ manager->mm_shrink.count_objects = &ttm_pool_shrink_count;
+ manager->mm_shrink.scan_objects = &ttm_pool_shrink_scan;
manager->mm_shrink.seeks = 1;
register_shrinker(&manager->mm_shrink);
}
diff --git a/drivers/gpu/drm/ttm/ttm_page_alloc_dma.c b/drivers/gpu/drm/ttm/ttm_page_alloc_dma.c
index b8b3943..b3b4f99 100644
--- a/drivers/gpu/drm/ttm/ttm_page_alloc_dma.c
+++ b/drivers/gpu/drm/ttm/ttm_page_alloc_dma.c
@@ -918,19 +918,6 @@ int ttm_dma_populate(struct ttm_dma_tt *ttm_dma, struct device *dev)
}
EXPORT_SYMBOL_GPL(ttm_dma_populate);
-/* Get good estimation how many pages are free in pools */
-static int ttm_dma_pool_get_num_unused_pages(void)
-{
- struct device_pools *p;
- unsigned total = 0;
-
- mutex_lock(&_manager->lock);
- list_for_each_entry(p, &_manager->pools, pools)
- total += p->pool->npages_free;
- mutex_unlock(&_manager->lock);
- return total;
-}
-
/* Put all pages in pages list to correct pool to wait for reuse */
void ttm_dma_unpopulate(struct ttm_dma_tt *ttm_dma, struct device *dev)
{
@@ -1002,18 +989,31 @@ EXPORT_SYMBOL_GPL(ttm_dma_unpopulate);
/**
* Callback for mm to request pool to reduce number of page held.
+ *
+ * XXX: (dchinner) Deadlock warning!
+ *
+ * ttm_dma_page_pool_free() does GFP_KERNEL memory allocation, and so attention
+ * needs to be paid to sc->gfp_mask to determine if this can be done or not.
+ * GFP_KERNEL memory allocation in a GFP_ATOMIC reclaim context woul dbe really
+ * bad.
+ *
+ * I'm getting sadder as I hear more pathetical whimpers about needing per-pool
+ * shrinkers
*/
-static int ttm_dma_pool_mm_shrink(struct shrinker *shrink,
- struct shrink_control *sc)
+static long
+ttm_dma_pool_shrink_scan(
+ struct shrinker *shrink,
+ struct shrink_control *sc)
{
static atomic_t start_pool = ATOMIC_INIT(0);
unsigned idx = 0;
unsigned pool_offset = atomic_add_return(1, &start_pool);
unsigned shrink_pages = sc->nr_to_scan;
struct device_pools *p;
+ long freed = 0;
if (list_empty(&_manager->pools))
- return 0;
+ return -1;
mutex_lock(&_manager->lock);
pool_offset = pool_offset % _manager->npools;
@@ -1029,18 +1029,35 @@ static int ttm_dma_pool_mm_shrink(struct shrinker *shrink,
continue;
nr_free = shrink_pages;
shrink_pages = ttm_dma_page_pool_free(p->pool, nr_free);
+ freed += nr_free - shrink_pages;
+
pr_debug("%s: (%s:%d) Asked to shrink %d, have %d more to go\n",
p->pool->dev_name, p->pool->name, current->pid,
nr_free, shrink_pages);
}
mutex_unlock(&_manager->lock);
- /* return estimated number of unused pages in pool */
- return ttm_dma_pool_get_num_unused_pages();
+ return freed;
+}
+
+static long
+ttm_dma_pool_shrink_count(
+ struct shrinker *shrink,
+ struct shrink_control *sc)
+{
+ struct device_pools *p;
+ long count = 0;
+
+ mutex_lock(&_manager->lock);
+ list_for_each_entry(p, &_manager->pools, pools)
+ count += p->pool->npages_free;
+ mutex_unlock(&_manager->lock);
+ return count;
}
static void ttm_dma_pool_mm_shrink_init(struct ttm_pool_manager *manager)
{
- manager->mm_shrink.shrink = &ttm_dma_pool_mm_shrink;
+ manager->mm_shrink.count_objects = &ttm_dma_pool_shrink_count;
+ manager->mm_shrink.scan_objects = &ttm_dma_pool_shrink_scan;
manager->mm_shrink.seeks = 1;
register_shrinker(&manager->mm_shrink);
}
diff --git a/drivers/md/bcache/btree.c b/drivers/md/bcache/btree.c
index 36688d6..e305f96 100644
--- a/drivers/md/bcache/btree.c
+++ b/drivers/md/bcache/btree.c
@@ -599,24 +599,12 @@ static int mca_reap(struct btree *b, struct closure *cl, unsigned min_order)
return 0;
}
-static int bch_mca_shrink(struct shrinker *shrink, struct shrink_control *sc)
+static long bch_mca_scan(struct shrinker *shrink, struct shrink_control *sc)
{
struct cache_set *c = container_of(shrink, struct cache_set, shrink);
struct btree *b, *t;
unsigned long i, nr = sc->nr_to_scan;
-
- if (c->shrinker_disabled)
- return 0;
-
- if (c->try_harder)
- return 0;
-
- /*
- * If nr == 0, we're supposed to return the number of items we have
- * cached. Not allowed to return -1.
- */
- if (!nr)
- return mca_can_free(c) * c->btree_pages;
+ long freed = 0;
/* Return -1 if we can't do anything right now */
if (sc->gfp_mask & __GFP_WAIT)
@@ -629,14 +617,14 @@ static int bch_mca_shrink(struct shrinker *shrink, struct shrink_control *sc)
i = 0;
list_for_each_entry_safe(b, t, &c->btree_cache_freeable, list) {
- if (!nr)
+ if (freed >= nr)
break;
if (++i > 3 &&
!mca_reap(b, NULL, 0)) {
mca_data_free(b);
rw_unlock(true, b);
- --nr;
+ freed++;
}
}
@@ -647,7 +635,7 @@ static int bch_mca_shrink(struct shrinker *shrink, struct shrink_control *sc)
if (list_empty(&c->btree_cache))
goto out;
- for (i = 0; nr && i < c->bucket_cache_used; i++) {
+ for (i = 0; i < c->bucket_cache_used; i++) {
b = list_first_entry(&c->btree_cache, struct btree, list);
list_rotate_left(&c->btree_cache);
@@ -656,14 +644,26 @@ static int bch_mca_shrink(struct shrinker *shrink, struct shrink_control *sc)
mca_bucket_free(b);
mca_data_free(b);
rw_unlock(true, b);
- --nr;
+ freed++;
} else
b->accessed = 0;
}
out:
- nr = mca_can_free(c) * c->btree_pages;
mutex_unlock(&c->bucket_lock);
- return nr;
+ return freed;
+}
+
+static long bch_mca_count(struct shrinker *shrink, struct shrink_control *sc)
+{
+ struct cache_set *c = container_of(shrink, struct cache_set, shrink);
+
+ if (c->shrinker_disabled)
+ return 0;
+
+ if (c->try_harder)
+ return 0;
+
+ return mca_can_free(c) * c->btree_pages;
}
void bch_btree_cache_free(struct cache_set *c)
@@ -732,7 +732,8 @@ int bch_btree_cache_alloc(struct cache_set *c)
c->verify_data = NULL;
#endif
- c->shrink.shrink = bch_mca_shrink;
+ c->shrink.count_objects = bch_mca_count;
+ c->shrink.scan_objects = bch_mca_scan;
c->shrink.seeks = 4;
c->shrink.batch = c->btree_pages * 2;
register_shrinker(&c->shrink);
diff --git a/drivers/md/bcache/sysfs.c b/drivers/md/bcache/sysfs.c
index 4d9cca4..fa8d048 100644
--- a/drivers/md/bcache/sysfs.c
+++ b/drivers/md/bcache/sysfs.c
@@ -535,7 +535,7 @@ STORE(__bch_cache_set)
struct shrink_control sc;
sc.gfp_mask = GFP_KERNEL;
sc.nr_to_scan = strtoul_or_return(buf);
- c->shrink.shrink(&c->shrink, &sc);
+ c->shrink.scan_objects(&c->shrink, &sc);
}
sysfs_strtoul(congested_read_threshold_us,
diff --git a/drivers/md/dm-bufio.c b/drivers/md/dm-bufio.c
index d489dfd..cdafc63 100644
--- a/drivers/md/dm-bufio.c
+++ b/drivers/md/dm-bufio.c
@@ -1383,62 +1383,80 @@ static int __cleanup_old_buffer(struct dm_buffer *b, gfp_t gfp,
unsigned long max_jiffies)
{
if (jiffies - b->last_accessed < max_jiffies)
- return 1;
+ return 0;
if (!(gfp & __GFP_IO)) {
if (test_bit(B_READING, &b->state) ||
test_bit(B_WRITING, &b->state) ||
test_bit(B_DIRTY, &b->state))
- return 1;
+ return 0;
}
if (b->hold_count)
- return 1;
+ return 0;
__make_buffer_clean(b);
__unlink_buffer(b);
__free_buffer_wake(b);
- return 0;
+ return 1;
}
-static void __scan(struct dm_bufio_client *c, unsigned long nr_to_scan,
- struct shrink_control *sc)
+static long __scan(struct dm_bufio_client *c, unsigned long nr_to_scan,
+ gfp_t gfp_mask)
{
int l;
struct dm_buffer *b, *tmp;
+ long freed = 0;
for (l = 0; l < LIST_SIZE; l++) {
- list_for_each_entry_safe_reverse(b, tmp, &c->lru[l], lru_list)
- if (!__cleanup_old_buffer(b, sc->gfp_mask, 0) &&
- !--nr_to_scan)
- return;
+ list_for_each_entry_safe_reverse(b, tmp, &c->lru[l], lru_list) {
+ freed += __cleanup_old_buffer(b, gfp_mask, 0);
+ if (!--nr_to_scan)
+ break;
+ }
dm_bufio_cond_resched();
}
+ return freed;
}
-static int shrink(struct shrinker *shrinker, struct shrink_control *sc)
+static long
+dm_bufio_shrink_scan(
+ struct shrinker *shrink,
+ struct shrink_control *sc)
{
struct dm_bufio_client *c =
- container_of(shrinker, struct dm_bufio_client, shrinker);
- unsigned long r;
- unsigned long nr_to_scan = sc->nr_to_scan;
+ container_of(shrink, struct dm_bufio_client, shrinker);
+ long freed;
if (sc->gfp_mask & __GFP_IO)
dm_bufio_lock(c);
else if (!dm_bufio_trylock(c))
- return !nr_to_scan ? 0 : -1;
+ return -1;
- if (nr_to_scan)
- __scan(c, nr_to_scan, sc);
+ freed = __scan(c, sc->nr_to_scan, sc->gfp_mask);
+ dm_bufio_unlock(c);
+ return freed;
+}
- r = c->n_buffers[LIST_CLEAN] + c->n_buffers[LIST_DIRTY];
- if (r > INT_MAX)
- r = INT_MAX;
+static long
+dm_bufio_shrink_count(
+ struct shrinker *shrink,
+ struct shrink_control *sc)
+{
+ struct dm_bufio_client *c =
+ container_of(shrink, struct dm_bufio_client, shrinker);
+ long count;
+
+ if (sc->gfp_mask & __GFP_IO)
+ dm_bufio_lock(c);
+ else if (!dm_bufio_trylock(c))
+ return 0;
+ count = c->n_buffers[LIST_CLEAN] + c->n_buffers[LIST_DIRTY];
dm_bufio_unlock(c);
+ return count;
- return r;
}
/*
@@ -1540,7 +1558,8 @@ struct dm_bufio_client *dm_bufio_client_create(struct block_device *bdev, unsign
__cache_size_refresh();
mutex_unlock(&dm_bufio_clients_lock);
- c->shrinker.shrink = shrink;
+ c->shrinker.count_objects = dm_bufio_shrink_count;
+ c->shrinker.scan_objects = dm_bufio_shrink_scan;
c->shrinker.seeks = 1;
c->shrinker.batch = 0;
register_shrinker(&c->shrinker);
@@ -1627,7 +1646,7 @@ static void cleanup_old_buffers(void)
struct dm_buffer *b;
b = list_entry(c->lru[LIST_CLEAN].prev,
struct dm_buffer, lru_list);
- if (__cleanup_old_buffer(b, 0, max_age * HZ))
+ if (!__cleanup_old_buffer(b, 0, max_age * HZ))
break;
dm_bufio_cond_resched();
}
diff --git a/drivers/staging/android/ashmem.c b/drivers/staging/android/ashmem.c
index 3240d34..951d944 100644
--- a/drivers/staging/android/ashmem.c
+++ b/drivers/staging/android/ashmem.c
@@ -341,27 +341,28 @@ out:
/*
* ashmem_shrink - our cache shrinker, called from mm/vmscan.c :: shrink_slab
*
- * 'nr_to_scan' is the number of objects (pages) to prune, or 0 to query how
- * many objects (pages) we have in total.
+ * 'nr_to_scan' is the number of objects to scan for freeing.
*
* 'gfp_mask' is the mask of the allocation that got us into this mess.
*
- * Return value is the number of objects (pages) remaining, or -1 if we cannot
+ * Return value is the number of objects freed or -1 if we cannot
* proceed without risk of deadlock (due to gfp_mask).
*
* We approximate LRU via least-recently-unpinned, jettisoning unpinned partial
* chunks of ashmem regions LRU-wise one-at-a-time until we hit 'nr_to_scan'
* pages freed.
*/
-static int ashmem_shrink(struct shrinker *s, struct shrink_control *sc)
+static long
+ashmem_shrink_scan(
+ struct shrinker *shrink,
+ struct shrink_control *sc)
{
struct ashmem_range *range, *next;
+ long freed = 0;
/* We might recurse into filesystem code, so bail out if necessary */
- if (sc->nr_to_scan && !(sc->gfp_mask & __GFP_FS))
+ if (!(sc->gfp_mask & __GFP_FS))
return -1;
- if (!sc->nr_to_scan)
- return lru_count;
mutex_lock(&ashmem_mutex);
list_for_each_entry_safe(range, next, &ashmem_lru_list, lru) {
@@ -374,17 +375,34 @@ static int ashmem_shrink(struct shrinker *s, struct shrink_control *sc)
range->purged = ASHMEM_WAS_PURGED;
lru_del(range);
- sc->nr_to_scan -= range_size(range);
- if (sc->nr_to_scan <= 0)
+ freed += range_size(range);
+ if (--sc->nr_to_scan <= 0)
break;
}
mutex_unlock(&ashmem_mutex);
+ return freed;
+}
+static long
+ashmem_shrink_count(
+ struct shrinker *shrink,
+ struct shrink_control *sc)
+{
+ /*
+ * note that lru_count is count of pages on the lru, not a count of
+ * objects on the list. This means the scan function needs to return the
+ * number of pages freed, not the number of objects scanned.
+ */
return lru_count;
}
static struct shrinker ashmem_shrinker = {
- .shrink = ashmem_shrink,
+ .count_objects = ashmem_shrink_count,
+ .scan_objects = ashmem_shrink_scan,
+ /*
+ * XXX (dchinner): I wish people would comment on why they need on
+ * significant changes to the default value here
+ */
.seeks = DEFAULT_SEEKS * 4,
};
@@ -690,14 +708,11 @@ static long ashmem_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
if (capable(CAP_SYS_ADMIN)) {
struct shrink_control sc = {
.gfp_mask = GFP_KERNEL,
- .nr_to_scan = 0,
+ .nr_to_scan = LONG_MAX,
};
nodes_setall(sc.nodes_to_scan);
-
- ret = ashmem_shrink(&ashmem_shrinker, &sc);
- sc.nr_to_scan = ret;
- ashmem_shrink(&ashmem_shrinker, &sc);
+ ashmem_shrink_scan(&ashmem_shrinker, &sc);
}
break;
}
diff --git a/drivers/staging/android/lowmemorykiller.c b/drivers/staging/android/lowmemorykiller.c
index fe74494..d23bfea 100644
--- a/drivers/staging/android/lowmemorykiller.c
+++ b/drivers/staging/android/lowmemorykiller.c
@@ -66,7 +66,15 @@ static unsigned long lowmem_deathpending_timeout;
pr_info(x); \
} while (0)
-static int lowmem_shrink(struct shrinker *s, struct shrink_control *sc)
+static long lowmem_count(struct shrinker *s, struct shrink_control *sc)
+{
+ return global_page_state(NR_ACTIVE_ANON) +
+ global_page_state(NR_ACTIVE_FILE) +
+ global_page_state(NR_INACTIVE_ANON) +
+ global_page_state(NR_INACTIVE_FILE);
+}
+
+static long lowmem_scan(struct shrinker *s, struct shrink_control *sc)
{
struct task_struct *tsk;
struct task_struct *selected = NULL;
@@ -92,19 +100,17 @@ static int lowmem_shrink(struct shrinker *s, struct shrink_control *sc)
break;
}
}
- if (sc->nr_to_scan > 0)
- lowmem_print(3, "lowmem_shrink %lu, %x, ofree %d %d, ma %hd\n",
- sc->nr_to_scan, sc->gfp_mask, other_free,
- other_file, min_score_adj);
- rem = global_page_state(NR_ACTIVE_ANON) +
- global_page_state(NR_ACTIVE_FILE) +
- global_page_state(NR_INACTIVE_ANON) +
- global_page_state(NR_INACTIVE_FILE);
- if (sc->nr_to_scan <= 0 || min_score_adj == OOM_SCORE_ADJ_MAX + 1) {
- lowmem_print(5, "lowmem_shrink %lu, %x, return %d\n",
- sc->nr_to_scan, sc->gfp_mask, rem);
- return rem;
+
+ lowmem_print(3, "lowmem_scan %lu, %x, ofree %d %d, ma %hd\n",
+ sc->nr_to_scan, sc->gfp_mask, other_free,
+ other_file, min_score_adj);
+
+ if (min_score_adj == OOM_SCORE_ADJ_MAX + 1) {
+ lowmem_print(5, "lowmem_scan %lu, %x, return 0\n",
+ sc->nr_to_scan, sc->gfp_mask);
+ return 0;
}
+
selected_oom_score_adj = min_score_adj;
rcu_read_lock();
@@ -154,16 +160,18 @@ static int lowmem_shrink(struct shrinker *s, struct shrink_control *sc)
lowmem_deathpending_timeout = jiffies + HZ;
send_sig(SIGKILL, selected, 0);
set_tsk_thread_flag(selected, TIF_MEMDIE);
- rem -= selected_tasksize;
+ rem += selected_tasksize;
}
- lowmem_print(4, "lowmem_shrink %lu, %x, return %d\n",
+
+ lowmem_print(4, "lowmem_scan %lu, %x, return %d\n",
sc->nr_to_scan, sc->gfp_mask, rem);
rcu_read_unlock();
return rem;
}
static struct shrinker lowmem_shrinker = {
- .shrink = lowmem_shrink,
+ .scan_objects = lowmem_scan,
+ .count_objects = lowmem_count,
.seeks = DEFAULT_SEEKS * 16
};
diff --git a/drivers/staging/zcache/zcache-main.c b/drivers/staging/zcache/zcache-main.c
index 522cb8e..bbfcd4f 100644
--- a/drivers/staging/zcache/zcache-main.c
+++ b/drivers/staging/zcache/zcache-main.c
@@ -1140,23 +1140,19 @@ static bool zcache_freeze;
* pageframes in use. FIXME POLICY: Probably the writeback should only occur
* if the eviction doesn't free enough pages.
*/
-static int shrink_zcache_memory(struct shrinker *shrink,
- struct shrink_control *sc)
+static long scan_zcache_memory(struct shrinker *shrink,
+ struct shrink_control *sc)
{
static bool in_progress;
- int ret = -1;
- int nr = sc->nr_to_scan;
int nr_evict = 0;
int nr_writeback = 0;
struct page *page;
int file_pageframes_inuse, anon_pageframes_inuse;
-
- if (nr <= 0)
- goto skip_evict;
+ long freed = 0;
/* don't allow more than one eviction thread at a time */
if (in_progress)
- goto skip_evict;
+ return 0;
in_progress = true;
@@ -1176,6 +1172,7 @@ static int shrink_zcache_memory(struct shrinker *shrink,
if (page == NULL)
break;
zcache_free_page(page);
+ freed++;
}
zcache_last_active_anon_pageframes =
@@ -1192,13 +1189,22 @@ static int shrink_zcache_memory(struct shrinker *shrink,
#ifdef CONFIG_ZCACHE_WRITEBACK
int writeback_ret;
writeback_ret = zcache_frontswap_writeback();
- if (writeback_ret == -ENOMEM)
+ if (writeback_ret != -ENOMEM)
+ freed++;
+ else
#endif
break;
}
in_progress = false;
-skip_evict:
+ return freed;
+}
+
+static long count_zcache_memory(struct shrinker *shrink,
+ struct shrink_control *sc)
+{
+ int ret = -1;
+
/* resample: has changed, but maybe not all the way yet */
zcache_last_active_file_pageframes =
global_page_state(NR_LRU_BASE + LRU_ACTIVE_FILE);
@@ -1212,7 +1218,8 @@ skip_evict:
}
static struct shrinker zcache_shrinker = {
- .shrink = shrink_zcache_memory,
+ .scan_objects = scan_zcache_memory,
+ .count_objects = count_zcache_memory,
.seeks = DEFAULT_SEEKS,
};
--
1.8.1.4
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^ permalink raw reply related [flat|nested] 151+ messages in thread* [PATCH v6 16/31] drivers: convert shrinkers to new count/scan API
@ 2013-05-12 18:13 ` Glauber Costa
0 siblings, 0 replies; 151+ messages in thread
From: Glauber Costa @ 2013-05-12 18:13 UTC (permalink / raw)
To: linux-mm
Cc: cgroups, Andrew Morton, Greg Thelen, kamezawa.hiroyu,
Michal Hocko, Johannes Weiner, linux-fsdevel, Dave Chinner,
Dave Chinner, Glauber Costa, Daniel Vetter, Kent Overstreet,
Arve Hjønnevåg, John Stultz, David Rientjes,
Jerome Glisse, Thomas Hellstrom
From: Dave Chinner <dchinner@redhat.com>
Convert the driver shrinkers to the new API. Most changes are
compile tested only because I either don't have the hardware or it's
staging stuff.
FWIW, the md and android code is pretty good, but the rest of it
makes me want to claw my eyes out. The amount of broken code I just
encountered is mind boggling. I've added comments explaining what
is broken, but I fear that some of the code would be best dealt with
by being dragged behind the bike shed, burying in mud up to it's
neck and then run over repeatedly with a blunt lawn mower.
Special mention goes to the zcache/zcache2 drivers. They can't
co-exist in the build at the same time, they are under different
menu options in menuconfig, they only show up when you've got the
right set of mm subsystem options configured and so even compile
testing is an exercise in pulling teeth. And that doesn't even take
into account the horrible, broken code...
[ glommer: fixes for i915, android lowmem, zcache, bcache ]
Signed-off-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Glauber Costa <glommer@openvz.org>
Acked-by: Mel Gorman <mgorman@suse.de>
CC: Daniel Vetter <daniel.vetter@ffwll.ch>
CC: Kent Overstreet <koverstreet@google.com>
CC: Arve Hjønnevåg <arve@android.com>
CC: John Stultz <john.stultz@linaro.org>
CC: David Rientjes <rientjes@google.com>
CC: Jerome Glisse <jglisse@redhat.com>
CC: Thomas Hellstrom <thellstrom@vmware.com>
---
drivers/gpu/drm/i915/i915_dma.c | 4 +-
drivers/gpu/drm/i915/i915_gem.c | 67 ++++++++++++++++++++++---------
drivers/gpu/drm/ttm/ttm_page_alloc.c | 48 ++++++++++++++--------
drivers/gpu/drm/ttm/ttm_page_alloc_dma.c | 55 ++++++++++++++++---------
drivers/md/bcache/btree.c | 43 ++++++++++----------
drivers/md/bcache/sysfs.c | 2 +-
drivers/md/dm-bufio.c | 65 +++++++++++++++++++-----------
drivers/staging/android/ashmem.c | 45 ++++++++++++++-------
drivers/staging/android/lowmemorykiller.c | 40 ++++++++++--------
drivers/staging/zcache/zcache-main.c | 29 ++++++++-----
10 files changed, 256 insertions(+), 142 deletions(-)
diff --git a/drivers/gpu/drm/i915/i915_dma.c b/drivers/gpu/drm/i915/i915_dma.c
index 3b315ba..cfe3373 100644
--- a/drivers/gpu/drm/i915/i915_dma.c
+++ b/drivers/gpu/drm/i915/i915_dma.c
@@ -1669,7 +1669,7 @@ int i915_driver_load(struct drm_device *dev, unsigned long flags)
return 0;
out_gem_unload:
- if (dev_priv->mm.inactive_shrinker.shrink)
+ if (dev_priv->mm.inactive_shrinker.scan_objects)
unregister_shrinker(&dev_priv->mm.inactive_shrinker);
if (dev->pdev->msi_enabled)
@@ -1705,7 +1705,7 @@ int i915_driver_unload(struct drm_device *dev)
i915_teardown_sysfs(dev);
- if (dev_priv->mm.inactive_shrinker.shrink)
+ if (dev_priv->mm.inactive_shrinker.scan_objects)
unregister_shrinker(&dev_priv->mm.inactive_shrinker);
mutex_lock(&dev->struct_mutex);
diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c
index 6165535..6b17122 100644
--- a/drivers/gpu/drm/i915/i915_gem.c
+++ b/drivers/gpu/drm/i915/i915_gem.c
@@ -53,10 +53,12 @@ static void i915_gem_object_update_fence(struct drm_i915_gem_object *obj,
struct drm_i915_fence_reg *fence,
bool enable);
-static int i915_gem_inactive_shrink(struct shrinker *shrinker,
+static long i915_gem_inactive_count(struct shrinker *shrinker,
struct shrink_control *sc);
+static long i915_gem_inactive_scan(struct shrinker *shrinker,
+ struct shrink_control *sc);
static long i915_gem_purge(struct drm_i915_private *dev_priv, long target);
-static void i915_gem_shrink_all(struct drm_i915_private *dev_priv);
+static long i915_gem_shrink_all(struct drm_i915_private *dev_priv);
static void i915_gem_object_truncate(struct drm_i915_gem_object *obj);
static inline void i915_gem_object_fence_lost(struct drm_i915_gem_object *obj)
@@ -1729,15 +1731,20 @@ i915_gem_purge(struct drm_i915_private *dev_priv, long target)
return __i915_gem_shrink(dev_priv, target, true);
}
-static void
+static long
i915_gem_shrink_all(struct drm_i915_private *dev_priv)
{
struct drm_i915_gem_object *obj, *next;
+ long freed = 0;
i915_gem_evict_everything(dev_priv->dev);
- list_for_each_entry_safe(obj, next, &dev_priv->mm.unbound_list, gtt_list)
+ list_for_each_entry_safe(obj, next, &dev_priv->mm.unbound_list, gtt_list) {
+ if (obj->pages_pin_count == 0)
+ freed += obj->base.size >> PAGE_SHIFT;
i915_gem_object_put_pages(obj);
+ }
+ return freed;
}
static int
@@ -4203,7 +4210,8 @@ i915_gem_load(struct drm_device *dev)
dev_priv->mm.interruptible = true;
- dev_priv->mm.inactive_shrinker.shrink = i915_gem_inactive_shrink;
+ dev_priv->mm.inactive_shrinker.scan_objects = i915_gem_inactive_scan;
+ dev_priv->mm.inactive_shrinker.count_objects = i915_gem_inactive_count;
dev_priv->mm.inactive_shrinker.seeks = DEFAULT_SEEKS;
register_shrinker(&dev_priv->mm.inactive_shrinker);
}
@@ -4426,8 +4434,8 @@ static bool mutex_is_locked_by(struct mutex *mutex, struct task_struct *task)
#endif
}
-static int
-i915_gem_inactive_shrink(struct shrinker *shrinker, struct shrink_control *sc)
+static long
+i915_gem_inactive_count(struct shrinker *shrinker, struct shrink_control *sc)
{
struct drm_i915_private *dev_priv =
container_of(shrinker,
@@ -4435,9 +4443,8 @@ i915_gem_inactive_shrink(struct shrinker *shrinker, struct shrink_control *sc)
mm.inactive_shrinker);
struct drm_device *dev = dev_priv->dev;
struct drm_i915_gem_object *obj;
- int nr_to_scan = sc->nr_to_scan;
bool unlock = true;
- int cnt;
+ long cnt;
if (!mutex_trylock(&dev->struct_mutex)) {
if (!mutex_is_locked_by(&dev->struct_mutex, current))
@@ -4449,15 +4456,6 @@ i915_gem_inactive_shrink(struct shrinker *shrinker, struct shrink_control *sc)
unlock = false;
}
- if (nr_to_scan) {
- nr_to_scan -= i915_gem_purge(dev_priv, nr_to_scan);
- if (nr_to_scan > 0)
- nr_to_scan -= __i915_gem_shrink(dev_priv, nr_to_scan,
- false);
- if (nr_to_scan > 0)
- i915_gem_shrink_all(dev_priv);
- }
-
cnt = 0;
list_for_each_entry(obj, &dev_priv->mm.unbound_list, gtt_list)
if (obj->pages_pin_count == 0)
@@ -4470,3 +4468,36 @@ i915_gem_inactive_shrink(struct shrinker *shrinker, struct shrink_control *sc)
mutex_unlock(&dev->struct_mutex);
return cnt;
}
+static long
+i915_gem_inactive_scan(struct shrinker *shrinker, struct shrink_control *sc)
+{
+ struct drm_i915_private *dev_priv =
+ container_of(shrinker,
+ struct drm_i915_private,
+ mm.inactive_shrinker);
+ struct drm_device *dev = dev_priv->dev;
+ int nr_to_scan = sc->nr_to_scan;
+ long freed;
+ bool unlock = true;
+
+ if (!mutex_trylock(&dev->struct_mutex)) {
+ if (!mutex_is_locked_by(&dev->struct_mutex, current))
+ return 0;
+
+ if (dev_priv->mm.shrinker_no_lock_stealing)
+ return 0;
+
+ unlock = false;
+ }
+
+ freed = i915_gem_purge(dev_priv, nr_to_scan);
+ if (freed < nr_to_scan)
+ freed += __i915_gem_shrink(dev_priv, nr_to_scan,
+ false);
+ if (freed < nr_to_scan)
+ freed += i915_gem_shrink_all(dev_priv);
+
+ if (unlock)
+ mutex_unlock(&dev->struct_mutex);
+ return freed;
+}
diff --git a/drivers/gpu/drm/ttm/ttm_page_alloc.c b/drivers/gpu/drm/ttm/ttm_page_alloc.c
index bd2a3b4..83058a2 100644
--- a/drivers/gpu/drm/ttm/ttm_page_alloc.c
+++ b/drivers/gpu/drm/ttm/ttm_page_alloc.c
@@ -377,28 +377,28 @@ out:
return nr_free;
}
-/* Get good estimation how many pages are free in pools */
-static int ttm_pool_get_num_unused_pages(void)
-{
- unsigned i;
- int total = 0;
- for (i = 0; i < NUM_POOLS; ++i)
- total += _manager->pools[i].npages;
-
- return total;
-}
-
/**
* Callback for mm to request pool to reduce number of page held.
+ *
+ * XXX: (dchinner) Deadlock warning!
+ *
+ * ttm_page_pool_free() does memory allocation using GFP_KERNEL. that means
+ * this can deadlock when called a sc->gfp_mask that is not equal to
+ * GFP_KERNEL.
+ *
+ * This code is crying out for a shrinker per pool....
*/
-static int ttm_pool_mm_shrink(struct shrinker *shrink,
- struct shrink_control *sc)
+static long
+ttm_pool_shrink_scan(
+ struct shrinker *shrink,
+ struct shrink_control *sc)
{
static atomic_t start_pool = ATOMIC_INIT(0);
unsigned i;
unsigned pool_offset = atomic_add_return(1, &start_pool);
struct ttm_page_pool *pool;
int shrink_pages = sc->nr_to_scan;
+ long freed = 0;
pool_offset = pool_offset % NUM_POOLS;
/* select start pool in round robin fashion */
@@ -408,14 +408,30 @@ static int ttm_pool_mm_shrink(struct shrinker *shrink,
break;
pool = &_manager->pools[(i + pool_offset)%NUM_POOLS];
shrink_pages = ttm_page_pool_free(pool, nr_free);
+ freed += nr_free - shrink_pages;
}
- /* return estimated number of unused pages in pool */
- return ttm_pool_get_num_unused_pages();
+ return freed;
+}
+
+
+static long
+ttm_pool_shrink_count(
+ struct shrinker *shrink,
+ struct shrink_control *sc)
+{
+ unsigned i;
+ long count = 0;
+
+ for (i = 0; i < NUM_POOLS; ++i)
+ count += _manager->pools[i].npages;
+
+ return count;
}
static void ttm_pool_mm_shrink_init(struct ttm_pool_manager *manager)
{
- manager->mm_shrink.shrink = &ttm_pool_mm_shrink;
+ manager->mm_shrink.count_objects = &ttm_pool_shrink_count;
+ manager->mm_shrink.scan_objects = &ttm_pool_shrink_scan;
manager->mm_shrink.seeks = 1;
register_shrinker(&manager->mm_shrink);
}
diff --git a/drivers/gpu/drm/ttm/ttm_page_alloc_dma.c b/drivers/gpu/drm/ttm/ttm_page_alloc_dma.c
index b8b3943..b3b4f99 100644
--- a/drivers/gpu/drm/ttm/ttm_page_alloc_dma.c
+++ b/drivers/gpu/drm/ttm/ttm_page_alloc_dma.c
@@ -918,19 +918,6 @@ int ttm_dma_populate(struct ttm_dma_tt *ttm_dma, struct device *dev)
}
EXPORT_SYMBOL_GPL(ttm_dma_populate);
-/* Get good estimation how many pages are free in pools */
-static int ttm_dma_pool_get_num_unused_pages(void)
-{
- struct device_pools *p;
- unsigned total = 0;
-
- mutex_lock(&_manager->lock);
- list_for_each_entry(p, &_manager->pools, pools)
- total += p->pool->npages_free;
- mutex_unlock(&_manager->lock);
- return total;
-}
-
/* Put all pages in pages list to correct pool to wait for reuse */
void ttm_dma_unpopulate(struct ttm_dma_tt *ttm_dma, struct device *dev)
{
@@ -1002,18 +989,31 @@ EXPORT_SYMBOL_GPL(ttm_dma_unpopulate);
/**
* Callback for mm to request pool to reduce number of page held.
+ *
+ * XXX: (dchinner) Deadlock warning!
+ *
+ * ttm_dma_page_pool_free() does GFP_KERNEL memory allocation, and so attention
+ * needs to be paid to sc->gfp_mask to determine if this can be done or not.
+ * GFP_KERNEL memory allocation in a GFP_ATOMIC reclaim context woul dbe really
+ * bad.
+ *
+ * I'm getting sadder as I hear more pathetical whimpers about needing per-pool
+ * shrinkers
*/
-static int ttm_dma_pool_mm_shrink(struct shrinker *shrink,
- struct shrink_control *sc)
+static long
+ttm_dma_pool_shrink_scan(
+ struct shrinker *shrink,
+ struct shrink_control *sc)
{
static atomic_t start_pool = ATOMIC_INIT(0);
unsigned idx = 0;
unsigned pool_offset = atomic_add_return(1, &start_pool);
unsigned shrink_pages = sc->nr_to_scan;
struct device_pools *p;
+ long freed = 0;
if (list_empty(&_manager->pools))
- return 0;
+ return -1;
mutex_lock(&_manager->lock);
pool_offset = pool_offset % _manager->npools;
@@ -1029,18 +1029,35 @@ static int ttm_dma_pool_mm_shrink(struct shrinker *shrink,
continue;
nr_free = shrink_pages;
shrink_pages = ttm_dma_page_pool_free(p->pool, nr_free);
+ freed += nr_free - shrink_pages;
+
pr_debug("%s: (%s:%d) Asked to shrink %d, have %d more to go\n",
p->pool->dev_name, p->pool->name, current->pid,
nr_free, shrink_pages);
}
mutex_unlock(&_manager->lock);
- /* return estimated number of unused pages in pool */
- return ttm_dma_pool_get_num_unused_pages();
+ return freed;
+}
+
+static long
+ttm_dma_pool_shrink_count(
+ struct shrinker *shrink,
+ struct shrink_control *sc)
+{
+ struct device_pools *p;
+ long count = 0;
+
+ mutex_lock(&_manager->lock);
+ list_for_each_entry(p, &_manager->pools, pools)
+ count += p->pool->npages_free;
+ mutex_unlock(&_manager->lock);
+ return count;
}
static void ttm_dma_pool_mm_shrink_init(struct ttm_pool_manager *manager)
{
- manager->mm_shrink.shrink = &ttm_dma_pool_mm_shrink;
+ manager->mm_shrink.count_objects = &ttm_dma_pool_shrink_count;
+ manager->mm_shrink.scan_objects = &ttm_dma_pool_shrink_scan;
manager->mm_shrink.seeks = 1;
register_shrinker(&manager->mm_shrink);
}
diff --git a/drivers/md/bcache/btree.c b/drivers/md/bcache/btree.c
index 36688d6..e305f96 100644
--- a/drivers/md/bcache/btree.c
+++ b/drivers/md/bcache/btree.c
@@ -599,24 +599,12 @@ static int mca_reap(struct btree *b, struct closure *cl, unsigned min_order)
return 0;
}
-static int bch_mca_shrink(struct shrinker *shrink, struct shrink_control *sc)
+static long bch_mca_scan(struct shrinker *shrink, struct shrink_control *sc)
{
struct cache_set *c = container_of(shrink, struct cache_set, shrink);
struct btree *b, *t;
unsigned long i, nr = sc->nr_to_scan;
-
- if (c->shrinker_disabled)
- return 0;
-
- if (c->try_harder)
- return 0;
-
- /*
- * If nr == 0, we're supposed to return the number of items we have
- * cached. Not allowed to return -1.
- */
- if (!nr)
- return mca_can_free(c) * c->btree_pages;
+ long freed = 0;
/* Return -1 if we can't do anything right now */
if (sc->gfp_mask & __GFP_WAIT)
@@ -629,14 +617,14 @@ static int bch_mca_shrink(struct shrinker *shrink, struct shrink_control *sc)
i = 0;
list_for_each_entry_safe(b, t, &c->btree_cache_freeable, list) {
- if (!nr)
+ if (freed >= nr)
break;
if (++i > 3 &&
!mca_reap(b, NULL, 0)) {
mca_data_free(b);
rw_unlock(true, b);
- --nr;
+ freed++;
}
}
@@ -647,7 +635,7 @@ static int bch_mca_shrink(struct shrinker *shrink, struct shrink_control *sc)
if (list_empty(&c->btree_cache))
goto out;
- for (i = 0; nr && i < c->bucket_cache_used; i++) {
+ for (i = 0; i < c->bucket_cache_used; i++) {
b = list_first_entry(&c->btree_cache, struct btree, list);
list_rotate_left(&c->btree_cache);
@@ -656,14 +644,26 @@ static int bch_mca_shrink(struct shrinker *shrink, struct shrink_control *sc)
mca_bucket_free(b);
mca_data_free(b);
rw_unlock(true, b);
- --nr;
+ freed++;
} else
b->accessed = 0;
}
out:
- nr = mca_can_free(c) * c->btree_pages;
mutex_unlock(&c->bucket_lock);
- return nr;
+ return freed;
+}
+
+static long bch_mca_count(struct shrinker *shrink, struct shrink_control *sc)
+{
+ struct cache_set *c = container_of(shrink, struct cache_set, shrink);
+
+ if (c->shrinker_disabled)
+ return 0;
+
+ if (c->try_harder)
+ return 0;
+
+ return mca_can_free(c) * c->btree_pages;
}
void bch_btree_cache_free(struct cache_set *c)
@@ -732,7 +732,8 @@ int bch_btree_cache_alloc(struct cache_set *c)
c->verify_data = NULL;
#endif
- c->shrink.shrink = bch_mca_shrink;
+ c->shrink.count_objects = bch_mca_count;
+ c->shrink.scan_objects = bch_mca_scan;
c->shrink.seeks = 4;
c->shrink.batch = c->btree_pages * 2;
register_shrinker(&c->shrink);
diff --git a/drivers/md/bcache/sysfs.c b/drivers/md/bcache/sysfs.c
index 4d9cca4..fa8d048 100644
--- a/drivers/md/bcache/sysfs.c
+++ b/drivers/md/bcache/sysfs.c
@@ -535,7 +535,7 @@ STORE(__bch_cache_set)
struct shrink_control sc;
sc.gfp_mask = GFP_KERNEL;
sc.nr_to_scan = strtoul_or_return(buf);
- c->shrink.shrink(&c->shrink, &sc);
+ c->shrink.scan_objects(&c->shrink, &sc);
}
sysfs_strtoul(congested_read_threshold_us,
diff --git a/drivers/md/dm-bufio.c b/drivers/md/dm-bufio.c
index d489dfd..cdafc63 100644
--- a/drivers/md/dm-bufio.c
+++ b/drivers/md/dm-bufio.c
@@ -1383,62 +1383,80 @@ static int __cleanup_old_buffer(struct dm_buffer *b, gfp_t gfp,
unsigned long max_jiffies)
{
if (jiffies - b->last_accessed < max_jiffies)
- return 1;
+ return 0;
if (!(gfp & __GFP_IO)) {
if (test_bit(B_READING, &b->state) ||
test_bit(B_WRITING, &b->state) ||
test_bit(B_DIRTY, &b->state))
- return 1;
+ return 0;
}
if (b->hold_count)
- return 1;
+ return 0;
__make_buffer_clean(b);
__unlink_buffer(b);
__free_buffer_wake(b);
- return 0;
+ return 1;
}
-static void __scan(struct dm_bufio_client *c, unsigned long nr_to_scan,
- struct shrink_control *sc)
+static long __scan(struct dm_bufio_client *c, unsigned long nr_to_scan,
+ gfp_t gfp_mask)
{
int l;
struct dm_buffer *b, *tmp;
+ long freed = 0;
for (l = 0; l < LIST_SIZE; l++) {
- list_for_each_entry_safe_reverse(b, tmp, &c->lru[l], lru_list)
- if (!__cleanup_old_buffer(b, sc->gfp_mask, 0) &&
- !--nr_to_scan)
- return;
+ list_for_each_entry_safe_reverse(b, tmp, &c->lru[l], lru_list) {
+ freed += __cleanup_old_buffer(b, gfp_mask, 0);
+ if (!--nr_to_scan)
+ break;
+ }
dm_bufio_cond_resched();
}
+ return freed;
}
-static int shrink(struct shrinker *shrinker, struct shrink_control *sc)
+static long
+dm_bufio_shrink_scan(
+ struct shrinker *shrink,
+ struct shrink_control *sc)
{
struct dm_bufio_client *c =
- container_of(shrinker, struct dm_bufio_client, shrinker);
- unsigned long r;
- unsigned long nr_to_scan = sc->nr_to_scan;
+ container_of(shrink, struct dm_bufio_client, shrinker);
+ long freed;
if (sc->gfp_mask & __GFP_IO)
dm_bufio_lock(c);
else if (!dm_bufio_trylock(c))
- return !nr_to_scan ? 0 : -1;
+ return -1;
- if (nr_to_scan)
- __scan(c, nr_to_scan, sc);
+ freed = __scan(c, sc->nr_to_scan, sc->gfp_mask);
+ dm_bufio_unlock(c);
+ return freed;
+}
- r = c->n_buffers[LIST_CLEAN] + c->n_buffers[LIST_DIRTY];
- if (r > INT_MAX)
- r = INT_MAX;
+static long
+dm_bufio_shrink_count(
+ struct shrinker *shrink,
+ struct shrink_control *sc)
+{
+ struct dm_bufio_client *c =
+ container_of(shrink, struct dm_bufio_client, shrinker);
+ long count;
+
+ if (sc->gfp_mask & __GFP_IO)
+ dm_bufio_lock(c);
+ else if (!dm_bufio_trylock(c))
+ return 0;
+ count = c->n_buffers[LIST_CLEAN] + c->n_buffers[LIST_DIRTY];
dm_bufio_unlock(c);
+ return count;
- return r;
}
/*
@@ -1540,7 +1558,8 @@ struct dm_bufio_client *dm_bufio_client_create(struct block_device *bdev, unsign
__cache_size_refresh();
mutex_unlock(&dm_bufio_clients_lock);
- c->shrinker.shrink = shrink;
+ c->shrinker.count_objects = dm_bufio_shrink_count;
+ c->shrinker.scan_objects = dm_bufio_shrink_scan;
c->shrinker.seeks = 1;
c->shrinker.batch = 0;
register_shrinker(&c->shrinker);
@@ -1627,7 +1646,7 @@ static void cleanup_old_buffers(void)
struct dm_buffer *b;
b = list_entry(c->lru[LIST_CLEAN].prev,
struct dm_buffer, lru_list);
- if (__cleanup_old_buffer(b, 0, max_age * HZ))
+ if (!__cleanup_old_buffer(b, 0, max_age * HZ))
break;
dm_bufio_cond_resched();
}
diff --git a/drivers/staging/android/ashmem.c b/drivers/staging/android/ashmem.c
index 3240d34..951d944 100644
--- a/drivers/staging/android/ashmem.c
+++ b/drivers/staging/android/ashmem.c
@@ -341,27 +341,28 @@ out:
/*
* ashmem_shrink - our cache shrinker, called from mm/vmscan.c :: shrink_slab
*
- * 'nr_to_scan' is the number of objects (pages) to prune, or 0 to query how
- * many objects (pages) we have in total.
+ * 'nr_to_scan' is the number of objects to scan for freeing.
*
* 'gfp_mask' is the mask of the allocation that got us into this mess.
*
- * Return value is the number of objects (pages) remaining, or -1 if we cannot
+ * Return value is the number of objects freed or -1 if we cannot
* proceed without risk of deadlock (due to gfp_mask).
*
* We approximate LRU via least-recently-unpinned, jettisoning unpinned partial
* chunks of ashmem regions LRU-wise one-at-a-time until we hit 'nr_to_scan'
* pages freed.
*/
-static int ashmem_shrink(struct shrinker *s, struct shrink_control *sc)
+static long
+ashmem_shrink_scan(
+ struct shrinker *shrink,
+ struct shrink_control *sc)
{
struct ashmem_range *range, *next;
+ long freed = 0;
/* We might recurse into filesystem code, so bail out if necessary */
- if (sc->nr_to_scan && !(sc->gfp_mask & __GFP_FS))
+ if (!(sc->gfp_mask & __GFP_FS))
return -1;
- if (!sc->nr_to_scan)
- return lru_count;
mutex_lock(&ashmem_mutex);
list_for_each_entry_safe(range, next, &ashmem_lru_list, lru) {
@@ -374,17 +375,34 @@ static int ashmem_shrink(struct shrinker *s, struct shrink_control *sc)
range->purged = ASHMEM_WAS_PURGED;
lru_del(range);
- sc->nr_to_scan -= range_size(range);
- if (sc->nr_to_scan <= 0)
+ freed += range_size(range);
+ if (--sc->nr_to_scan <= 0)
break;
}
mutex_unlock(&ashmem_mutex);
+ return freed;
+}
+static long
+ashmem_shrink_count(
+ struct shrinker *shrink,
+ struct shrink_control *sc)
+{
+ /*
+ * note that lru_count is count of pages on the lru, not a count of
+ * objects on the list. This means the scan function needs to return the
+ * number of pages freed, not the number of objects scanned.
+ */
return lru_count;
}
static struct shrinker ashmem_shrinker = {
- .shrink = ashmem_shrink,
+ .count_objects = ashmem_shrink_count,
+ .scan_objects = ashmem_shrink_scan,
+ /*
+ * XXX (dchinner): I wish people would comment on why they need on
+ * significant changes to the default value here
+ */
.seeks = DEFAULT_SEEKS * 4,
};
@@ -690,14 +708,11 @@ static long ashmem_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
if (capable(CAP_SYS_ADMIN)) {
struct shrink_control sc = {
.gfp_mask = GFP_KERNEL,
- .nr_to_scan = 0,
+ .nr_to_scan = LONG_MAX,
};
nodes_setall(sc.nodes_to_scan);
-
- ret = ashmem_shrink(&ashmem_shrinker, &sc);
- sc.nr_to_scan = ret;
- ashmem_shrink(&ashmem_shrinker, &sc);
+ ashmem_shrink_scan(&ashmem_shrinker, &sc);
}
break;
}
diff --git a/drivers/staging/android/lowmemorykiller.c b/drivers/staging/android/lowmemorykiller.c
index fe74494..d23bfea 100644
--- a/drivers/staging/android/lowmemorykiller.c
+++ b/drivers/staging/android/lowmemorykiller.c
@@ -66,7 +66,15 @@ static unsigned long lowmem_deathpending_timeout;
pr_info(x); \
} while (0)
-static int lowmem_shrink(struct shrinker *s, struct shrink_control *sc)
+static long lowmem_count(struct shrinker *s, struct shrink_control *sc)
+{
+ return global_page_state(NR_ACTIVE_ANON) +
+ global_page_state(NR_ACTIVE_FILE) +
+ global_page_state(NR_INACTIVE_ANON) +
+ global_page_state(NR_INACTIVE_FILE);
+}
+
+static long lowmem_scan(struct shrinker *s, struct shrink_control *sc)
{
struct task_struct *tsk;
struct task_struct *selected = NULL;
@@ -92,19 +100,17 @@ static int lowmem_shrink(struct shrinker *s, struct shrink_control *sc)
break;
}
}
- if (sc->nr_to_scan > 0)
- lowmem_print(3, "lowmem_shrink %lu, %x, ofree %d %d, ma %hd\n",
- sc->nr_to_scan, sc->gfp_mask, other_free,
- other_file, min_score_adj);
- rem = global_page_state(NR_ACTIVE_ANON) +
- global_page_state(NR_ACTIVE_FILE) +
- global_page_state(NR_INACTIVE_ANON) +
- global_page_state(NR_INACTIVE_FILE);
- if (sc->nr_to_scan <= 0 || min_score_adj == OOM_SCORE_ADJ_MAX + 1) {
- lowmem_print(5, "lowmem_shrink %lu, %x, return %d\n",
- sc->nr_to_scan, sc->gfp_mask, rem);
- return rem;
+
+ lowmem_print(3, "lowmem_scan %lu, %x, ofree %d %d, ma %hd\n",
+ sc->nr_to_scan, sc->gfp_mask, other_free,
+ other_file, min_score_adj);
+
+ if (min_score_adj == OOM_SCORE_ADJ_MAX + 1) {
+ lowmem_print(5, "lowmem_scan %lu, %x, return 0\n",
+ sc->nr_to_scan, sc->gfp_mask);
+ return 0;
}
+
selected_oom_score_adj = min_score_adj;
rcu_read_lock();
@@ -154,16 +160,18 @@ static int lowmem_shrink(struct shrinker *s, struct shrink_control *sc)
lowmem_deathpending_timeout = jiffies + HZ;
send_sig(SIGKILL, selected, 0);
set_tsk_thread_flag(selected, TIF_MEMDIE);
- rem -= selected_tasksize;
+ rem += selected_tasksize;
}
- lowmem_print(4, "lowmem_shrink %lu, %x, return %d\n",
+
+ lowmem_print(4, "lowmem_scan %lu, %x, return %d\n",
sc->nr_to_scan, sc->gfp_mask, rem);
rcu_read_unlock();
return rem;
}
static struct shrinker lowmem_shrinker = {
- .shrink = lowmem_shrink,
+ .scan_objects = lowmem_scan,
+ .count_objects = lowmem_count,
.seeks = DEFAULT_SEEKS * 16
};
diff --git a/drivers/staging/zcache/zcache-main.c b/drivers/staging/zcache/zcache-main.c
index 522cb8e..bbfcd4f 100644
--- a/drivers/staging/zcache/zcache-main.c
+++ b/drivers/staging/zcache/zcache-main.c
@@ -1140,23 +1140,19 @@ static bool zcache_freeze;
* pageframes in use. FIXME POLICY: Probably the writeback should only occur
* if the eviction doesn't free enough pages.
*/
-static int shrink_zcache_memory(struct shrinker *shrink,
- struct shrink_control *sc)
+static long scan_zcache_memory(struct shrinker *shrink,
+ struct shrink_control *sc)
{
static bool in_progress;
- int ret = -1;
- int nr = sc->nr_to_scan;
int nr_evict = 0;
int nr_writeback = 0;
struct page *page;
int file_pageframes_inuse, anon_pageframes_inuse;
-
- if (nr <= 0)
- goto skip_evict;
+ long freed = 0;
/* don't allow more than one eviction thread at a time */
if (in_progress)
- goto skip_evict;
+ return 0;
in_progress = true;
@@ -1176,6 +1172,7 @@ static int shrink_zcache_memory(struct shrinker *shrink,
if (page == NULL)
break;
zcache_free_page(page);
+ freed++;
}
zcache_last_active_anon_pageframes =
@@ -1192,13 +1189,22 @@ static int shrink_zcache_memory(struct shrinker *shrink,
#ifdef CONFIG_ZCACHE_WRITEBACK
int writeback_ret;
writeback_ret = zcache_frontswap_writeback();
- if (writeback_ret == -ENOMEM)
+ if (writeback_ret != -ENOMEM)
+ freed++;
+ else
#endif
break;
}
in_progress = false;
-skip_evict:
+ return freed;
+}
+
+static long count_zcache_memory(struct shrinker *shrink,
+ struct shrink_control *sc)
+{
+ int ret = -1;
+
/* resample: has changed, but maybe not all the way yet */
zcache_last_active_file_pageframes =
global_page_state(NR_LRU_BASE + LRU_ACTIVE_FILE);
@@ -1212,7 +1218,8 @@ skip_evict:
}
static struct shrinker zcache_shrinker = {
- .shrink = shrink_zcache_memory,
+ .scan_objects = scan_zcache_memory,
+ .count_objects = count_zcache_memory,
.seeks = DEFAULT_SEEKS,
};
--
1.8.1.4
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^ permalink raw reply related [flat|nested] 151+ messages in thread* [PATCH v6 16/31] drivers: convert shrinkers to new count/scan API
@ 2013-05-12 18:13 ` Glauber Costa
0 siblings, 0 replies; 151+ messages in thread
From: Glauber Costa @ 2013-05-12 18:13 UTC (permalink / raw)
To: linux-mm
Cc: cgroups, Andrew Morton, Greg Thelen, kamezawa.hiroyu,
Michal Hocko, Johannes Weiner, linux-fsdevel, Dave Chinner,
Dave Chinner, Glauber Costa, Daniel Vetter, Kent Overstreet,
Arve Hjønnevåg, John Stultz, David Rientjes,
Jerome Glisse, Thomas Hellstrom
From: Dave Chinner <dchinner@redhat.com>
Convert the driver shrinkers to the new API. Most changes are
compile tested only because I either don't have the hardware or it's
staging stuff.
FWIW, the md and android code is pretty good, but the rest of it
makes me want to claw my eyes out. The amount of broken code I just
encountered is mind boggling. I've added comments explaining what
is broken, but I fear that some of the code would be best dealt with
by being dragged behind the bike shed, burying in mud up to it's
neck and then run over repeatedly with a blunt lawn mower.
Special mention goes to the zcache/zcache2 drivers. They can't
co-exist in the build at the same time, they are under different
menu options in menuconfig, they only show up when you've got the
right set of mm subsystem options configured and so even compile
testing is an exercise in pulling teeth. And that doesn't even take
into account the horrible, broken code...
[ glommer: fixes for i915, android lowmem, zcache, bcache ]
Signed-off-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Glauber Costa <glommer@openvz.org>
Acked-by: Mel Gorman <mgorman@suse.de>
CC: Daniel Vetter <daniel.vetter@ffwll.ch>
CC: Kent Overstreet <koverstreet@google.com>
CC: Arve HjA,nnevAJPYg <arve@android.com>
CC: John Stultz <john.stultz@linaro.org>
CC: David Rientjes <rientjes@google.com>
CC: Jerome Glisse <jglisse@redhat.com>
CC: Thomas Hellstrom <thellstrom@vmware.com>
---
drivers/gpu/drm/i915/i915_dma.c | 4 +-
drivers/gpu/drm/i915/i915_gem.c | 67 ++++++++++++++++++++++---------
drivers/gpu/drm/ttm/ttm_page_alloc.c | 48 ++++++++++++++--------
drivers/gpu/drm/ttm/ttm_page_alloc_dma.c | 55 ++++++++++++++++---------
drivers/md/bcache/btree.c | 43 ++++++++++----------
drivers/md/bcache/sysfs.c | 2 +-
drivers/md/dm-bufio.c | 65 +++++++++++++++++++-----------
drivers/staging/android/ashmem.c | 45 ++++++++++++++-------
drivers/staging/android/lowmemorykiller.c | 40 ++++++++++--------
drivers/staging/zcache/zcache-main.c | 29 ++++++++-----
10 files changed, 256 insertions(+), 142 deletions(-)
diff --git a/drivers/gpu/drm/i915/i915_dma.c b/drivers/gpu/drm/i915/i915_dma.c
index 3b315ba..cfe3373 100644
--- a/drivers/gpu/drm/i915/i915_dma.c
+++ b/drivers/gpu/drm/i915/i915_dma.c
@@ -1669,7 +1669,7 @@ int i915_driver_load(struct drm_device *dev, unsigned long flags)
return 0;
out_gem_unload:
- if (dev_priv->mm.inactive_shrinker.shrink)
+ if (dev_priv->mm.inactive_shrinker.scan_objects)
unregister_shrinker(&dev_priv->mm.inactive_shrinker);
if (dev->pdev->msi_enabled)
@@ -1705,7 +1705,7 @@ int i915_driver_unload(struct drm_device *dev)
i915_teardown_sysfs(dev);
- if (dev_priv->mm.inactive_shrinker.shrink)
+ if (dev_priv->mm.inactive_shrinker.scan_objects)
unregister_shrinker(&dev_priv->mm.inactive_shrinker);
mutex_lock(&dev->struct_mutex);
diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c
index 6165535..6b17122 100644
--- a/drivers/gpu/drm/i915/i915_gem.c
+++ b/drivers/gpu/drm/i915/i915_gem.c
@@ -53,10 +53,12 @@ static void i915_gem_object_update_fence(struct drm_i915_gem_object *obj,
struct drm_i915_fence_reg *fence,
bool enable);
-static int i915_gem_inactive_shrink(struct shrinker *shrinker,
+static long i915_gem_inactive_count(struct shrinker *shrinker,
struct shrink_control *sc);
+static long i915_gem_inactive_scan(struct shrinker *shrinker,
+ struct shrink_control *sc);
static long i915_gem_purge(struct drm_i915_private *dev_priv, long target);
-static void i915_gem_shrink_all(struct drm_i915_private *dev_priv);
+static long i915_gem_shrink_all(struct drm_i915_private *dev_priv);
static void i915_gem_object_truncate(struct drm_i915_gem_object *obj);
static inline void i915_gem_object_fence_lost(struct drm_i915_gem_object *obj)
@@ -1729,15 +1731,20 @@ i915_gem_purge(struct drm_i915_private *dev_priv, long target)
return __i915_gem_shrink(dev_priv, target, true);
}
-static void
+static long
i915_gem_shrink_all(struct drm_i915_private *dev_priv)
{
struct drm_i915_gem_object *obj, *next;
+ long freed = 0;
i915_gem_evict_everything(dev_priv->dev);
- list_for_each_entry_safe(obj, next, &dev_priv->mm.unbound_list, gtt_list)
+ list_for_each_entry_safe(obj, next, &dev_priv->mm.unbound_list, gtt_list) {
+ if (obj->pages_pin_count == 0)
+ freed += obj->base.size >> PAGE_SHIFT;
i915_gem_object_put_pages(obj);
+ }
+ return freed;
}
static int
@@ -4203,7 +4210,8 @@ i915_gem_load(struct drm_device *dev)
dev_priv->mm.interruptible = true;
- dev_priv->mm.inactive_shrinker.shrink = i915_gem_inactive_shrink;
+ dev_priv->mm.inactive_shrinker.scan_objects = i915_gem_inactive_scan;
+ dev_priv->mm.inactive_shrinker.count_objects = i915_gem_inactive_count;
dev_priv->mm.inactive_shrinker.seeks = DEFAULT_SEEKS;
register_shrinker(&dev_priv->mm.inactive_shrinker);
}
@@ -4426,8 +4434,8 @@ static bool mutex_is_locked_by(struct mutex *mutex, struct task_struct *task)
#endif
}
-static int
-i915_gem_inactive_shrink(struct shrinker *shrinker, struct shrink_control *sc)
+static long
+i915_gem_inactive_count(struct shrinker *shrinker, struct shrink_control *sc)
{
struct drm_i915_private *dev_priv =
container_of(shrinker,
@@ -4435,9 +4443,8 @@ i915_gem_inactive_shrink(struct shrinker *shrinker, struct shrink_control *sc)
mm.inactive_shrinker);
struct drm_device *dev = dev_priv->dev;
struct drm_i915_gem_object *obj;
- int nr_to_scan = sc->nr_to_scan;
bool unlock = true;
- int cnt;
+ long cnt;
if (!mutex_trylock(&dev->struct_mutex)) {
if (!mutex_is_locked_by(&dev->struct_mutex, current))
@@ -4449,15 +4456,6 @@ i915_gem_inactive_shrink(struct shrinker *shrinker, struct shrink_control *sc)
unlock = false;
}
- if (nr_to_scan) {
- nr_to_scan -= i915_gem_purge(dev_priv, nr_to_scan);
- if (nr_to_scan > 0)
- nr_to_scan -= __i915_gem_shrink(dev_priv, nr_to_scan,
- false);
- if (nr_to_scan > 0)
- i915_gem_shrink_all(dev_priv);
- }
-
cnt = 0;
list_for_each_entry(obj, &dev_priv->mm.unbound_list, gtt_list)
if (obj->pages_pin_count == 0)
@@ -4470,3 +4468,36 @@ i915_gem_inactive_shrink(struct shrinker *shrinker, struct shrink_control *sc)
mutex_unlock(&dev->struct_mutex);
return cnt;
}
+static long
+i915_gem_inactive_scan(struct shrinker *shrinker, struct shrink_control *sc)
+{
+ struct drm_i915_private *dev_priv =
+ container_of(shrinker,
+ struct drm_i915_private,
+ mm.inactive_shrinker);
+ struct drm_device *dev = dev_priv->dev;
+ int nr_to_scan = sc->nr_to_scan;
+ long freed;
+ bool unlock = true;
+
+ if (!mutex_trylock(&dev->struct_mutex)) {
+ if (!mutex_is_locked_by(&dev->struct_mutex, current))
+ return 0;
+
+ if (dev_priv->mm.shrinker_no_lock_stealing)
+ return 0;
+
+ unlock = false;
+ }
+
+ freed = i915_gem_purge(dev_priv, nr_to_scan);
+ if (freed < nr_to_scan)
+ freed += __i915_gem_shrink(dev_priv, nr_to_scan,
+ false);
+ if (freed < nr_to_scan)
+ freed += i915_gem_shrink_all(dev_priv);
+
+ if (unlock)
+ mutex_unlock(&dev->struct_mutex);
+ return freed;
+}
diff --git a/drivers/gpu/drm/ttm/ttm_page_alloc.c b/drivers/gpu/drm/ttm/ttm_page_alloc.c
index bd2a3b4..83058a2 100644
--- a/drivers/gpu/drm/ttm/ttm_page_alloc.c
+++ b/drivers/gpu/drm/ttm/ttm_page_alloc.c
@@ -377,28 +377,28 @@ out:
return nr_free;
}
-/* Get good estimation how many pages are free in pools */
-static int ttm_pool_get_num_unused_pages(void)
-{
- unsigned i;
- int total = 0;
- for (i = 0; i < NUM_POOLS; ++i)
- total += _manager->pools[i].npages;
-
- return total;
-}
-
/**
* Callback for mm to request pool to reduce number of page held.
+ *
+ * XXX: (dchinner) Deadlock warning!
+ *
+ * ttm_page_pool_free() does memory allocation using GFP_KERNEL. that means
+ * this can deadlock when called a sc->gfp_mask that is not equal to
+ * GFP_KERNEL.
+ *
+ * This code is crying out for a shrinker per pool....
*/
-static int ttm_pool_mm_shrink(struct shrinker *shrink,
- struct shrink_control *sc)
+static long
+ttm_pool_shrink_scan(
+ struct shrinker *shrink,
+ struct shrink_control *sc)
{
static atomic_t start_pool = ATOMIC_INIT(0);
unsigned i;
unsigned pool_offset = atomic_add_return(1, &start_pool);
struct ttm_page_pool *pool;
int shrink_pages = sc->nr_to_scan;
+ long freed = 0;
pool_offset = pool_offset % NUM_POOLS;
/* select start pool in round robin fashion */
@@ -408,14 +408,30 @@ static int ttm_pool_mm_shrink(struct shrinker *shrink,
break;
pool = &_manager->pools[(i + pool_offset)%NUM_POOLS];
shrink_pages = ttm_page_pool_free(pool, nr_free);
+ freed += nr_free - shrink_pages;
}
- /* return estimated number of unused pages in pool */
- return ttm_pool_get_num_unused_pages();
+ return freed;
+}
+
+
+static long
+ttm_pool_shrink_count(
+ struct shrinker *shrink,
+ struct shrink_control *sc)
+{
+ unsigned i;
+ long count = 0;
+
+ for (i = 0; i < NUM_POOLS; ++i)
+ count += _manager->pools[i].npages;
+
+ return count;
}
static void ttm_pool_mm_shrink_init(struct ttm_pool_manager *manager)
{
- manager->mm_shrink.shrink = &ttm_pool_mm_shrink;
+ manager->mm_shrink.count_objects = &ttm_pool_shrink_count;
+ manager->mm_shrink.scan_objects = &ttm_pool_shrink_scan;
manager->mm_shrink.seeks = 1;
register_shrinker(&manager->mm_shrink);
}
diff --git a/drivers/gpu/drm/ttm/ttm_page_alloc_dma.c b/drivers/gpu/drm/ttm/ttm_page_alloc_dma.c
index b8b3943..b3b4f99 100644
--- a/drivers/gpu/drm/ttm/ttm_page_alloc_dma.c
+++ b/drivers/gpu/drm/ttm/ttm_page_alloc_dma.c
@@ -918,19 +918,6 @@ int ttm_dma_populate(struct ttm_dma_tt *ttm_dma, struct device *dev)
}
EXPORT_SYMBOL_GPL(ttm_dma_populate);
-/* Get good estimation how many pages are free in pools */
-static int ttm_dma_pool_get_num_unused_pages(void)
-{
- struct device_pools *p;
- unsigned total = 0;
-
- mutex_lock(&_manager->lock);
- list_for_each_entry(p, &_manager->pools, pools)
- total += p->pool->npages_free;
- mutex_unlock(&_manager->lock);
- return total;
-}
-
/* Put all pages in pages list to correct pool to wait for reuse */
void ttm_dma_unpopulate(struct ttm_dma_tt *ttm_dma, struct device *dev)
{
@@ -1002,18 +989,31 @@ EXPORT_SYMBOL_GPL(ttm_dma_unpopulate);
/**
* Callback for mm to request pool to reduce number of page held.
+ *
+ * XXX: (dchinner) Deadlock warning!
+ *
+ * ttm_dma_page_pool_free() does GFP_KERNEL memory allocation, and so attention
+ * needs to be paid to sc->gfp_mask to determine if this can be done or not.
+ * GFP_KERNEL memory allocation in a GFP_ATOMIC reclaim context woul dbe really
+ * bad.
+ *
+ * I'm getting sadder as I hear more pathetical whimpers about needing per-pool
+ * shrinkers
*/
-static int ttm_dma_pool_mm_shrink(struct shrinker *shrink,
- struct shrink_control *sc)
+static long
+ttm_dma_pool_shrink_scan(
+ struct shrinker *shrink,
+ struct shrink_control *sc)
{
static atomic_t start_pool = ATOMIC_INIT(0);
unsigned idx = 0;
unsigned pool_offset = atomic_add_return(1, &start_pool);
unsigned shrink_pages = sc->nr_to_scan;
struct device_pools *p;
+ long freed = 0;
if (list_empty(&_manager->pools))
- return 0;
+ return -1;
mutex_lock(&_manager->lock);
pool_offset = pool_offset % _manager->npools;
@@ -1029,18 +1029,35 @@ static int ttm_dma_pool_mm_shrink(struct shrinker *shrink,
continue;
nr_free = shrink_pages;
shrink_pages = ttm_dma_page_pool_free(p->pool, nr_free);
+ freed += nr_free - shrink_pages;
+
pr_debug("%s: (%s:%d) Asked to shrink %d, have %d more to go\n",
p->pool->dev_name, p->pool->name, current->pid,
nr_free, shrink_pages);
}
mutex_unlock(&_manager->lock);
- /* return estimated number of unused pages in pool */
- return ttm_dma_pool_get_num_unused_pages();
+ return freed;
+}
+
+static long
+ttm_dma_pool_shrink_count(
+ struct shrinker *shrink,
+ struct shrink_control *sc)
+{
+ struct device_pools *p;
+ long count = 0;
+
+ mutex_lock(&_manager->lock);
+ list_for_each_entry(p, &_manager->pools, pools)
+ count += p->pool->npages_free;
+ mutex_unlock(&_manager->lock);
+ return count;
}
static void ttm_dma_pool_mm_shrink_init(struct ttm_pool_manager *manager)
{
- manager->mm_shrink.shrink = &ttm_dma_pool_mm_shrink;
+ manager->mm_shrink.count_objects = &ttm_dma_pool_shrink_count;
+ manager->mm_shrink.scan_objects = &ttm_dma_pool_shrink_scan;
manager->mm_shrink.seeks = 1;
register_shrinker(&manager->mm_shrink);
}
diff --git a/drivers/md/bcache/btree.c b/drivers/md/bcache/btree.c
index 36688d6..e305f96 100644
--- a/drivers/md/bcache/btree.c
+++ b/drivers/md/bcache/btree.c
@@ -599,24 +599,12 @@ static int mca_reap(struct btree *b, struct closure *cl, unsigned min_order)
return 0;
}
-static int bch_mca_shrink(struct shrinker *shrink, struct shrink_control *sc)
+static long bch_mca_scan(struct shrinker *shrink, struct shrink_control *sc)
{
struct cache_set *c = container_of(shrink, struct cache_set, shrink);
struct btree *b, *t;
unsigned long i, nr = sc->nr_to_scan;
-
- if (c->shrinker_disabled)
- return 0;
-
- if (c->try_harder)
- return 0;
-
- /*
- * If nr == 0, we're supposed to return the number of items we have
- * cached. Not allowed to return -1.
- */
- if (!nr)
- return mca_can_free(c) * c->btree_pages;
+ long freed = 0;
/* Return -1 if we can't do anything right now */
if (sc->gfp_mask & __GFP_WAIT)
@@ -629,14 +617,14 @@ static int bch_mca_shrink(struct shrinker *shrink, struct shrink_control *sc)
i = 0;
list_for_each_entry_safe(b, t, &c->btree_cache_freeable, list) {
- if (!nr)
+ if (freed >= nr)
break;
if (++i > 3 &&
!mca_reap(b, NULL, 0)) {
mca_data_free(b);
rw_unlock(true, b);
- --nr;
+ freed++;
}
}
@@ -647,7 +635,7 @@ static int bch_mca_shrink(struct shrinker *shrink, struct shrink_control *sc)
if (list_empty(&c->btree_cache))
goto out;
- for (i = 0; nr && i < c->bucket_cache_used; i++) {
+ for (i = 0; i < c->bucket_cache_used; i++) {
b = list_first_entry(&c->btree_cache, struct btree, list);
list_rotate_left(&c->btree_cache);
@@ -656,14 +644,26 @@ static int bch_mca_shrink(struct shrinker *shrink, struct shrink_control *sc)
mca_bucket_free(b);
mca_data_free(b);
rw_unlock(true, b);
- --nr;
+ freed++;
} else
b->accessed = 0;
}
out:
- nr = mca_can_free(c) * c->btree_pages;
mutex_unlock(&c->bucket_lock);
- return nr;
+ return freed;
+}
+
+static long bch_mca_count(struct shrinker *shrink, struct shrink_control *sc)
+{
+ struct cache_set *c = container_of(shrink, struct cache_set, shrink);
+
+ if (c->shrinker_disabled)
+ return 0;
+
+ if (c->try_harder)
+ return 0;
+
+ return mca_can_free(c) * c->btree_pages;
}
void bch_btree_cache_free(struct cache_set *c)
@@ -732,7 +732,8 @@ int bch_btree_cache_alloc(struct cache_set *c)
c->verify_data = NULL;
#endif
- c->shrink.shrink = bch_mca_shrink;
+ c->shrink.count_objects = bch_mca_count;
+ c->shrink.scan_objects = bch_mca_scan;
c->shrink.seeks = 4;
c->shrink.batch = c->btree_pages * 2;
register_shrinker(&c->shrink);
diff --git a/drivers/md/bcache/sysfs.c b/drivers/md/bcache/sysfs.c
index 4d9cca4..fa8d048 100644
--- a/drivers/md/bcache/sysfs.c
+++ b/drivers/md/bcache/sysfs.c
@@ -535,7 +535,7 @@ STORE(__bch_cache_set)
struct shrink_control sc;
sc.gfp_mask = GFP_KERNEL;
sc.nr_to_scan = strtoul_or_return(buf);
- c->shrink.shrink(&c->shrink, &sc);
+ c->shrink.scan_objects(&c->shrink, &sc);
}
sysfs_strtoul(congested_read_threshold_us,
diff --git a/drivers/md/dm-bufio.c b/drivers/md/dm-bufio.c
index d489dfd..cdafc63 100644
--- a/drivers/md/dm-bufio.c
+++ b/drivers/md/dm-bufio.c
@@ -1383,62 +1383,80 @@ static int __cleanup_old_buffer(struct dm_buffer *b, gfp_t gfp,
unsigned long max_jiffies)
{
if (jiffies - b->last_accessed < max_jiffies)
- return 1;
+ return 0;
if (!(gfp & __GFP_IO)) {
if (test_bit(B_READING, &b->state) ||
test_bit(B_WRITING, &b->state) ||
test_bit(B_DIRTY, &b->state))
- return 1;
+ return 0;
}
if (b->hold_count)
- return 1;
+ return 0;
__make_buffer_clean(b);
__unlink_buffer(b);
__free_buffer_wake(b);
- return 0;
+ return 1;
}
-static void __scan(struct dm_bufio_client *c, unsigned long nr_to_scan,
- struct shrink_control *sc)
+static long __scan(struct dm_bufio_client *c, unsigned long nr_to_scan,
+ gfp_t gfp_mask)
{
int l;
struct dm_buffer *b, *tmp;
+ long freed = 0;
for (l = 0; l < LIST_SIZE; l++) {
- list_for_each_entry_safe_reverse(b, tmp, &c->lru[l], lru_list)
- if (!__cleanup_old_buffer(b, sc->gfp_mask, 0) &&
- !--nr_to_scan)
- return;
+ list_for_each_entry_safe_reverse(b, tmp, &c->lru[l], lru_list) {
+ freed += __cleanup_old_buffer(b, gfp_mask, 0);
+ if (!--nr_to_scan)
+ break;
+ }
dm_bufio_cond_resched();
}
+ return freed;
}
-static int shrink(struct shrinker *shrinker, struct shrink_control *sc)
+static long
+dm_bufio_shrink_scan(
+ struct shrinker *shrink,
+ struct shrink_control *sc)
{
struct dm_bufio_client *c =
- container_of(shrinker, struct dm_bufio_client, shrinker);
- unsigned long r;
- unsigned long nr_to_scan = sc->nr_to_scan;
+ container_of(shrink, struct dm_bufio_client, shrinker);
+ long freed;
if (sc->gfp_mask & __GFP_IO)
dm_bufio_lock(c);
else if (!dm_bufio_trylock(c))
- return !nr_to_scan ? 0 : -1;
+ return -1;
- if (nr_to_scan)
- __scan(c, nr_to_scan, sc);
+ freed = __scan(c, sc->nr_to_scan, sc->gfp_mask);
+ dm_bufio_unlock(c);
+ return freed;
+}
- r = c->n_buffers[LIST_CLEAN] + c->n_buffers[LIST_DIRTY];
- if (r > INT_MAX)
- r = INT_MAX;
+static long
+dm_bufio_shrink_count(
+ struct shrinker *shrink,
+ struct shrink_control *sc)
+{
+ struct dm_bufio_client *c =
+ container_of(shrink, struct dm_bufio_client, shrinker);
+ long count;
+
+ if (sc->gfp_mask & __GFP_IO)
+ dm_bufio_lock(c);
+ else if (!dm_bufio_trylock(c))
+ return 0;
+ count = c->n_buffers[LIST_CLEAN] + c->n_buffers[LIST_DIRTY];
dm_bufio_unlock(c);
+ return count;
- return r;
}
/*
@@ -1540,7 +1558,8 @@ struct dm_bufio_client *dm_bufio_client_create(struct block_device *bdev, unsign
__cache_size_refresh();
mutex_unlock(&dm_bufio_clients_lock);
- c->shrinker.shrink = shrink;
+ c->shrinker.count_objects = dm_bufio_shrink_count;
+ c->shrinker.scan_objects = dm_bufio_shrink_scan;
c->shrinker.seeks = 1;
c->shrinker.batch = 0;
register_shrinker(&c->shrinker);
@@ -1627,7 +1646,7 @@ static void cleanup_old_buffers(void)
struct dm_buffer *b;
b = list_entry(c->lru[LIST_CLEAN].prev,
struct dm_buffer, lru_list);
- if (__cleanup_old_buffer(b, 0, max_age * HZ))
+ if (!__cleanup_old_buffer(b, 0, max_age * HZ))
break;
dm_bufio_cond_resched();
}
diff --git a/drivers/staging/android/ashmem.c b/drivers/staging/android/ashmem.c
index 3240d34..951d944 100644
--- a/drivers/staging/android/ashmem.c
+++ b/drivers/staging/android/ashmem.c
@@ -341,27 +341,28 @@ out:
/*
* ashmem_shrink - our cache shrinker, called from mm/vmscan.c :: shrink_slab
*
- * 'nr_to_scan' is the number of objects (pages) to prune, or 0 to query how
- * many objects (pages) we have in total.
+ * 'nr_to_scan' is the number of objects to scan for freeing.
*
* 'gfp_mask' is the mask of the allocation that got us into this mess.
*
- * Return value is the number of objects (pages) remaining, or -1 if we cannot
+ * Return value is the number of objects freed or -1 if we cannot
* proceed without risk of deadlock (due to gfp_mask).
*
* We approximate LRU via least-recently-unpinned, jettisoning unpinned partial
* chunks of ashmem regions LRU-wise one-at-a-time until we hit 'nr_to_scan'
* pages freed.
*/
-static int ashmem_shrink(struct shrinker *s, struct shrink_control *sc)
+static long
+ashmem_shrink_scan(
+ struct shrinker *shrink,
+ struct shrink_control *sc)
{
struct ashmem_range *range, *next;
+ long freed = 0;
/* We might recurse into filesystem code, so bail out if necessary */
- if (sc->nr_to_scan && !(sc->gfp_mask & __GFP_FS))
+ if (!(sc->gfp_mask & __GFP_FS))
return -1;
- if (!sc->nr_to_scan)
- return lru_count;
mutex_lock(&ashmem_mutex);
list_for_each_entry_safe(range, next, &ashmem_lru_list, lru) {
@@ -374,17 +375,34 @@ static int ashmem_shrink(struct shrinker *s, struct shrink_control *sc)
range->purged = ASHMEM_WAS_PURGED;
lru_del(range);
- sc->nr_to_scan -= range_size(range);
- if (sc->nr_to_scan <= 0)
+ freed += range_size(range);
+ if (--sc->nr_to_scan <= 0)
break;
}
mutex_unlock(&ashmem_mutex);
+ return freed;
+}
+static long
+ashmem_shrink_count(
+ struct shrinker *shrink,
+ struct shrink_control *sc)
+{
+ /*
+ * note that lru_count is count of pages on the lru, not a count of
+ * objects on the list. This means the scan function needs to return the
+ * number of pages freed, not the number of objects scanned.
+ */
return lru_count;
}
static struct shrinker ashmem_shrinker = {
- .shrink = ashmem_shrink,
+ .count_objects = ashmem_shrink_count,
+ .scan_objects = ashmem_shrink_scan,
+ /*
+ * XXX (dchinner): I wish people would comment on why they need on
+ * significant changes to the default value here
+ */
.seeks = DEFAULT_SEEKS * 4,
};
@@ -690,14 +708,11 @@ static long ashmem_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
if (capable(CAP_SYS_ADMIN)) {
struct shrink_control sc = {
.gfp_mask = GFP_KERNEL,
- .nr_to_scan = 0,
+ .nr_to_scan = LONG_MAX,
};
nodes_setall(sc.nodes_to_scan);
-
- ret = ashmem_shrink(&ashmem_shrinker, &sc);
- sc.nr_to_scan = ret;
- ashmem_shrink(&ashmem_shrinker, &sc);
+ ashmem_shrink_scan(&ashmem_shrinker, &sc);
}
break;
}
diff --git a/drivers/staging/android/lowmemorykiller.c b/drivers/staging/android/lowmemorykiller.c
index fe74494..d23bfea 100644
--- a/drivers/staging/android/lowmemorykiller.c
+++ b/drivers/staging/android/lowmemorykiller.c
@@ -66,7 +66,15 @@ static unsigned long lowmem_deathpending_timeout;
pr_info(x); \
} while (0)
-static int lowmem_shrink(struct shrinker *s, struct shrink_control *sc)
+static long lowmem_count(struct shrinker *s, struct shrink_control *sc)
+{
+ return global_page_state(NR_ACTIVE_ANON) +
+ global_page_state(NR_ACTIVE_FILE) +
+ global_page_state(NR_INACTIVE_ANON) +
+ global_page_state(NR_INACTIVE_FILE);
+}
+
+static long lowmem_scan(struct shrinker *s, struct shrink_control *sc)
{
struct task_struct *tsk;
struct task_struct *selected = NULL;
@@ -92,19 +100,17 @@ static int lowmem_shrink(struct shrinker *s, struct shrink_control *sc)
break;
}
}
- if (sc->nr_to_scan > 0)
- lowmem_print(3, "lowmem_shrink %lu, %x, ofree %d %d, ma %hd\n",
- sc->nr_to_scan, sc->gfp_mask, other_free,
- other_file, min_score_adj);
- rem = global_page_state(NR_ACTIVE_ANON) +
- global_page_state(NR_ACTIVE_FILE) +
- global_page_state(NR_INACTIVE_ANON) +
- global_page_state(NR_INACTIVE_FILE);
- if (sc->nr_to_scan <= 0 || min_score_adj == OOM_SCORE_ADJ_MAX + 1) {
- lowmem_print(5, "lowmem_shrink %lu, %x, return %d\n",
- sc->nr_to_scan, sc->gfp_mask, rem);
- return rem;
+
+ lowmem_print(3, "lowmem_scan %lu, %x, ofree %d %d, ma %hd\n",
+ sc->nr_to_scan, sc->gfp_mask, other_free,
+ other_file, min_score_adj);
+
+ if (min_score_adj == OOM_SCORE_ADJ_MAX + 1) {
+ lowmem_print(5, "lowmem_scan %lu, %x, return 0\n",
+ sc->nr_to_scan, sc->gfp_mask);
+ return 0;
}
+
selected_oom_score_adj = min_score_adj;
rcu_read_lock();
@@ -154,16 +160,18 @@ static int lowmem_shrink(struct shrinker *s, struct shrink_control *sc)
lowmem_deathpending_timeout = jiffies + HZ;
send_sig(SIGKILL, selected, 0);
set_tsk_thread_flag(selected, TIF_MEMDIE);
- rem -= selected_tasksize;
+ rem += selected_tasksize;
}
- lowmem_print(4, "lowmem_shrink %lu, %x, return %d\n",
+
+ lowmem_print(4, "lowmem_scan %lu, %x, return %d\n",
sc->nr_to_scan, sc->gfp_mask, rem);
rcu_read_unlock();
return rem;
}
static struct shrinker lowmem_shrinker = {
- .shrink = lowmem_shrink,
+ .scan_objects = lowmem_scan,
+ .count_objects = lowmem_count,
.seeks = DEFAULT_SEEKS * 16
};
diff --git a/drivers/staging/zcache/zcache-main.c b/drivers/staging/zcache/zcache-main.c
index 522cb8e..bbfcd4f 100644
--- a/drivers/staging/zcache/zcache-main.c
+++ b/drivers/staging/zcache/zcache-main.c
@@ -1140,23 +1140,19 @@ static bool zcache_freeze;
* pageframes in use. FIXME POLICY: Probably the writeback should only occur
* if the eviction doesn't free enough pages.
*/
-static int shrink_zcache_memory(struct shrinker *shrink,
- struct shrink_control *sc)
+static long scan_zcache_memory(struct shrinker *shrink,
+ struct shrink_control *sc)
{
static bool in_progress;
- int ret = -1;
- int nr = sc->nr_to_scan;
int nr_evict = 0;
int nr_writeback = 0;
struct page *page;
int file_pageframes_inuse, anon_pageframes_inuse;
-
- if (nr <= 0)
- goto skip_evict;
+ long freed = 0;
/* don't allow more than one eviction thread at a time */
if (in_progress)
- goto skip_evict;
+ return 0;
in_progress = true;
@@ -1176,6 +1172,7 @@ static int shrink_zcache_memory(struct shrinker *shrink,
if (page == NULL)
break;
zcache_free_page(page);
+ freed++;
}
zcache_last_active_anon_pageframes =
@@ -1192,13 +1189,22 @@ static int shrink_zcache_memory(struct shrinker *shrink,
#ifdef CONFIG_ZCACHE_WRITEBACK
int writeback_ret;
writeback_ret = zcache_frontswap_writeback();
- if (writeback_ret == -ENOMEM)
+ if (writeback_ret != -ENOMEM)
+ freed++;
+ else
#endif
break;
}
in_progress = false;
-skip_evict:
+ return freed;
+}
+
+static long count_zcache_memory(struct shrinker *shrink,
+ struct shrink_control *sc)
+{
+ int ret = -1;
+
/* resample: has changed, but maybe not all the way yet */
zcache_last_active_file_pageframes =
global_page_state(NR_LRU_BASE + LRU_ACTIVE_FILE);
@@ -1212,7 +1218,8 @@ skip_evict:
}
static struct shrinker zcache_shrinker = {
- .shrink = shrink_zcache_memory,
+ .scan_objects = scan_zcache_memory,
+ .count_objects = count_zcache_memory,
.seeks = DEFAULT_SEEKS,
};
--
1.8.1.4
--
To unsubscribe, send a message with 'unsubscribe linux-mm' in
the body to majordomo@kvack.org. For more info on Linux MM,
see: http://www.linux-mm.org/ .
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^ permalink raw reply related [flat|nested] 151+ messages in thread
* [PATCH v6 17/31] i915: bail out earlier when shrinker cannot acquire mutex
2013-05-12 18:13 ` Glauber Costa
(?)
@ 2013-05-12 18:13 ` Glauber Costa
-1 siblings, 0 replies; 151+ messages in thread
From: Glauber Costa @ 2013-05-12 18:13 UTC (permalink / raw)
To: linux-mm
Cc: cgroups, Andrew Morton, Greg Thelen, kamezawa.hiroyu,
Michal Hocko, Johannes Weiner, linux-fsdevel, Dave Chinner,
Glauber Costa, Dave Chinner, Mel Gorman, Daniel Vetter,
Kent Overstreet
The main shrinker driver will keep trying for a while to free objects if
the returned value from the shrink scan procedure is 0. That means "no
objects now", but a retry could very well succeed.
A negative value has a different meaning. It means it is impossible to
shrink, and we would better bail out soon. We find this behavior more
appropriate for the case where the lock cannot be taken. Specially given
the hammer behavior of the i915: if another thread is already shrinking,
we are likely not to be able to shrink anything anyway when we finally
acquire the mutex.
Signed-off-by: Glauber Costa <glommer@openvz.org>
CC: Dave Chinner <dchinner@redhat.com>
CC: Mel Gorman <mgorman@suse.de>
CC: Daniel Vetter <daniel.vetter@ffwll.ch>
CC: Kent Overstreet <koverstreet@google.com>
---
drivers/gpu/drm/i915/i915_gem.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c
index 6b17122..52b3ac1 100644
--- a/drivers/gpu/drm/i915/i915_gem.c
+++ b/drivers/gpu/drm/i915/i915_gem.c
@@ -4448,10 +4448,10 @@ i915_gem_inactive_count(struct shrinker *shrinker, struct shrink_control *sc)
if (!mutex_trylock(&dev->struct_mutex)) {
if (!mutex_is_locked_by(&dev->struct_mutex, current))
- return 0;
+ return -1;
if (dev_priv->mm.shrinker_no_lock_stealing)
- return 0;
+ return -1;
unlock = false;
}
--
1.8.1.4
^ permalink raw reply related [flat|nested] 151+ messages in thread* [PATCH v6 17/31] i915: bail out earlier when shrinker cannot acquire mutex
@ 2013-05-12 18:13 ` Glauber Costa
0 siblings, 0 replies; 151+ messages in thread
From: Glauber Costa @ 2013-05-12 18:13 UTC (permalink / raw)
To: linux-mm
Cc: cgroups, Andrew Morton, Greg Thelen, kamezawa.hiroyu,
Michal Hocko, Johannes Weiner, linux-fsdevel, Dave Chinner,
Glauber Costa, Dave Chinner, Mel Gorman, Daniel Vetter,
Kent Overstreet
The main shrinker driver will keep trying for a while to free objects if
the returned value from the shrink scan procedure is 0. That means "no
objects now", but a retry could very well succeed.
A negative value has a different meaning. It means it is impossible to
shrink, and we would better bail out soon. We find this behavior more
appropriate for the case where the lock cannot be taken. Specially given
the hammer behavior of the i915: if another thread is already shrinking,
we are likely not to be able to shrink anything anyway when we finally
acquire the mutex.
Signed-off-by: Glauber Costa <glommer@openvz.org>
CC: Dave Chinner <dchinner@redhat.com>
CC: Mel Gorman <mgorman@suse.de>
CC: Daniel Vetter <daniel.vetter@ffwll.ch>
CC: Kent Overstreet <koverstreet@google.com>
---
drivers/gpu/drm/i915/i915_gem.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c
index 6b17122..52b3ac1 100644
--- a/drivers/gpu/drm/i915/i915_gem.c
+++ b/drivers/gpu/drm/i915/i915_gem.c
@@ -4448,10 +4448,10 @@ i915_gem_inactive_count(struct shrinker *shrinker, struct shrink_control *sc)
if (!mutex_trylock(&dev->struct_mutex)) {
if (!mutex_is_locked_by(&dev->struct_mutex, current))
- return 0;
+ return -1;
if (dev_priv->mm.shrinker_no_lock_stealing)
- return 0;
+ return -1;
unlock = false;
}
--
1.8.1.4
^ permalink raw reply related [flat|nested] 151+ messages in thread* [PATCH v6 17/31] i915: bail out earlier when shrinker cannot acquire mutex
@ 2013-05-12 18:13 ` Glauber Costa
0 siblings, 0 replies; 151+ messages in thread
From: Glauber Costa @ 2013-05-12 18:13 UTC (permalink / raw)
To: linux-mm
Cc: cgroups, Andrew Morton, Greg Thelen, kamezawa.hiroyu,
Michal Hocko, Johannes Weiner, linux-fsdevel, Dave Chinner,
Glauber Costa, Dave Chinner, Mel Gorman, Daniel Vetter,
Kent Overstreet
The main shrinker driver will keep trying for a while to free objects if
the returned value from the shrink scan procedure is 0. That means "no
objects now", but a retry could very well succeed.
A negative value has a different meaning. It means it is impossible to
shrink, and we would better bail out soon. We find this behavior more
appropriate for the case where the lock cannot be taken. Specially given
the hammer behavior of the i915: if another thread is already shrinking,
we are likely not to be able to shrink anything anyway when we finally
acquire the mutex.
Signed-off-by: Glauber Costa <glommer@openvz.org>
CC: Dave Chinner <dchinner@redhat.com>
CC: Mel Gorman <mgorman@suse.de>
CC: Daniel Vetter <daniel.vetter@ffwll.ch>
CC: Kent Overstreet <koverstreet@google.com>
---
drivers/gpu/drm/i915/i915_gem.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c
index 6b17122..52b3ac1 100644
--- a/drivers/gpu/drm/i915/i915_gem.c
+++ b/drivers/gpu/drm/i915/i915_gem.c
@@ -4448,10 +4448,10 @@ i915_gem_inactive_count(struct shrinker *shrinker, struct shrink_control *sc)
if (!mutex_trylock(&dev->struct_mutex)) {
if (!mutex_is_locked_by(&dev->struct_mutex, current))
- return 0;
+ return -1;
if (dev_priv->mm.shrinker_no_lock_stealing)
- return 0;
+ return -1;
unlock = false;
}
--
1.8.1.4
--
To unsubscribe, send a message with 'unsubscribe linux-mm' in
the body to majordomo@kvack.org. For more info on Linux MM,
see: http://www.linux-mm.org/ .
Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a>
^ permalink raw reply related [flat|nested] 151+ messages in thread
* [PATCH v6 18/31] shrinker: convert remaining shrinkers to count/scan API
2013-05-12 18:13 ` Glauber Costa
(?)
@ 2013-05-12 18:13 ` Glauber Costa
-1 siblings, 0 replies; 151+ messages in thread
From: Glauber Costa @ 2013-05-12 18:13 UTC (permalink / raw)
To: linux-mm
Cc: cgroups, Andrew Morton, Greg Thelen, kamezawa.hiroyu,
Michal Hocko, Johannes Weiner, linux-fsdevel, Dave Chinner,
Dave Chinner, Glauber Costa, Marcelo Tosatti, Gleb Natapov,
Chuck Lever, J. Bruce Fields, Trond Myklebust
From: Dave Chinner <dchinner@redhat.com>
Convert the remaining couple of random shrinkers in the tree to the
new API.
Signed-off-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Glauber Costa <glommer@openvz.org>
CC: Marcelo Tosatti <mtosatti@redhat.com>
CC: Gleb Natapov <gleb@redhat.com>
CC: Chuck Lever <chuck.lever@oracle.com>
CC: J. Bruce Fields <bfields@redhat.com>
CC: Trond Myklebust <Trond.Myklebust@netapp.com>
---
arch/x86/kvm/mmu.c | 28 +++++++++++++++++++++-------
net/sunrpc/auth.c | 45 +++++++++++++++++++++++++++++++--------------
2 files changed, 52 insertions(+), 21 deletions(-)
diff --git a/arch/x86/kvm/mmu.c b/arch/x86/kvm/mmu.c
index 004cc87..19b4edf 100644
--- a/arch/x86/kvm/mmu.c
+++ b/arch/x86/kvm/mmu.c
@@ -4212,13 +4212,14 @@ restart:
spin_unlock(&kvm->mmu_lock);
}
-static int mmu_shrink(struct shrinker *shrink, struct shrink_control *sc)
+static long
+mmu_shrink_scan(
+ struct shrinker *shrink,
+ struct shrink_control *sc)
{
struct kvm *kvm;
int nr_to_scan = sc->nr_to_scan;
-
- if (nr_to_scan == 0)
- goto out;
+ long freed = 0;
raw_spin_lock(&kvm_lock);
@@ -4246,24 +4247,37 @@ static int mmu_shrink(struct shrinker *shrink, struct shrink_control *sc)
idx = srcu_read_lock(&kvm->srcu);
spin_lock(&kvm->mmu_lock);
- prepare_zap_oldest_mmu_page(kvm, &invalid_list);
+ freed += prepare_zap_oldest_mmu_page(kvm, &invalid_list);
kvm_mmu_commit_zap_page(kvm, &invalid_list);
spin_unlock(&kvm->mmu_lock);
srcu_read_unlock(&kvm->srcu, idx);
+ /*
+ * unfair on small ones
+ * per-vm shrinkers cry out
+ * sadness comes quickly
+ */
list_move_tail(&kvm->vm_list, &vm_list);
break;
}
raw_spin_unlock(&kvm_lock);
+ return freed;
-out:
+}
+
+static long
+mmu_shrink_count(
+ struct shrinker *shrink,
+ struct shrink_control *sc)
+{
return percpu_counter_read_positive(&kvm_total_used_mmu_pages);
}
static struct shrinker mmu_shrinker = {
- .shrink = mmu_shrink,
+ .count_objects = mmu_shrink_count,
+ .scan_objects = mmu_shrink_scan,
.seeks = DEFAULT_SEEKS * 10,
};
diff --git a/net/sunrpc/auth.c b/net/sunrpc/auth.c
index ed2fdd2..9ce0976 100644
--- a/net/sunrpc/auth.c
+++ b/net/sunrpc/auth.c
@@ -413,12 +413,13 @@ EXPORT_SYMBOL_GPL(rpcauth_destroy_credcache);
/*
* Remove stale credentials. Avoid sleeping inside the loop.
*/
-static int
+static long
rpcauth_prune_expired(struct list_head *free, int nr_to_scan)
{
spinlock_t *cache_lock;
struct rpc_cred *cred, *next;
unsigned long expired = jiffies - RPC_AUTH_EXPIRY_MORATORIUM;
+ long freed = 0;
list_for_each_entry_safe(cred, next, &cred_unused, cr_lru) {
@@ -430,10 +431,11 @@ rpcauth_prune_expired(struct list_head *free, int nr_to_scan)
*/
if (time_in_range(cred->cr_expire, expired, jiffies) &&
test_bit(RPCAUTH_CRED_HASHED, &cred->cr_flags) != 0)
- return 0;
+ break;
list_del_init(&cred->cr_lru);
number_cred_unused--;
+ freed++;
if (atomic_read(&cred->cr_count) != 0)
continue;
@@ -446,29 +448,43 @@ rpcauth_prune_expired(struct list_head *free, int nr_to_scan)
}
spin_unlock(cache_lock);
}
- return (number_cred_unused / 100) * sysctl_vfs_cache_pressure;
+ return freed;
}
/*
* Run memory cache shrinker.
*/
-static int
-rpcauth_cache_shrinker(struct shrinker *shrink, struct shrink_control *sc)
+static long
+rpcauth_cache_shrink_scan(
+ struct shrinker *shrink,
+ struct shrink_control *sc)
+
{
LIST_HEAD(free);
- int res;
- int nr_to_scan = sc->nr_to_scan;
- gfp_t gfp_mask = sc->gfp_mask;
+ long freed;
+
+ if ((sc->gfp_mask & GFP_KERNEL) != GFP_KERNEL)
+ return -1;
- if ((gfp_mask & GFP_KERNEL) != GFP_KERNEL)
- return (nr_to_scan == 0) ? 0 : -1;
+ /* nothing left, don't come back */
if (list_empty(&cred_unused))
- return 0;
+ return -1;
+
spin_lock(&rpc_credcache_lock);
- res = rpcauth_prune_expired(&free, nr_to_scan);
+ freed = rpcauth_prune_expired(&free, sc->nr_to_scan);
spin_unlock(&rpc_credcache_lock);
rpcauth_destroy_credlist(&free);
- return res;
+
+ return freed;
+}
+
+static long
+rpcauth_cache_shrink_count(
+ struct shrinker *shrink,
+ struct shrink_control *sc)
+
+{
+ return (number_cred_unused / 100) * sysctl_vfs_cache_pressure;
}
/*
@@ -784,7 +800,8 @@ rpcauth_uptodatecred(struct rpc_task *task)
}
static struct shrinker rpc_cred_shrinker = {
- .shrink = rpcauth_cache_shrinker,
+ .count_objects = rpcauth_cache_shrink_count,
+ .scan_objects = rpcauth_cache_shrink_scan,
.seeks = DEFAULT_SEEKS,
};
--
1.8.1.4
^ permalink raw reply related [flat|nested] 151+ messages in thread* [PATCH v6 18/31] shrinker: convert remaining shrinkers to count/scan API
@ 2013-05-12 18:13 ` Glauber Costa
0 siblings, 0 replies; 151+ messages in thread
From: Glauber Costa @ 2013-05-12 18:13 UTC (permalink / raw)
To: linux-mm
Cc: cgroups, Andrew Morton, Greg Thelen, kamezawa.hiroyu,
Michal Hocko, Johannes Weiner, linux-fsdevel, Dave Chinner,
Dave Chinner, Glauber Costa, Marcelo Tosatti, Gleb Natapov,
Chuck Lever, J. Bruce Fields, Trond Myklebust
From: Dave Chinner <dchinner@redhat.com>
Convert the remaining couple of random shrinkers in the tree to the
new API.
Signed-off-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Glauber Costa <glommer@openvz.org>
CC: Marcelo Tosatti <mtosatti@redhat.com>
CC: Gleb Natapov <gleb@redhat.com>
CC: Chuck Lever <chuck.lever@oracle.com>
CC: J. Bruce Fields <bfields@redhat.com>
CC: Trond Myklebust <Trond.Myklebust@netapp.com>
---
arch/x86/kvm/mmu.c | 28 +++++++++++++++++++++-------
net/sunrpc/auth.c | 45 +++++++++++++++++++++++++++++++--------------
2 files changed, 52 insertions(+), 21 deletions(-)
diff --git a/arch/x86/kvm/mmu.c b/arch/x86/kvm/mmu.c
index 004cc87..19b4edf 100644
--- a/arch/x86/kvm/mmu.c
+++ b/arch/x86/kvm/mmu.c
@@ -4212,13 +4212,14 @@ restart:
spin_unlock(&kvm->mmu_lock);
}
-static int mmu_shrink(struct shrinker *shrink, struct shrink_control *sc)
+static long
+mmu_shrink_scan(
+ struct shrinker *shrink,
+ struct shrink_control *sc)
{
struct kvm *kvm;
int nr_to_scan = sc->nr_to_scan;
-
- if (nr_to_scan == 0)
- goto out;
+ long freed = 0;
raw_spin_lock(&kvm_lock);
@@ -4246,24 +4247,37 @@ static int mmu_shrink(struct shrinker *shrink, struct shrink_control *sc)
idx = srcu_read_lock(&kvm->srcu);
spin_lock(&kvm->mmu_lock);
- prepare_zap_oldest_mmu_page(kvm, &invalid_list);
+ freed += prepare_zap_oldest_mmu_page(kvm, &invalid_list);
kvm_mmu_commit_zap_page(kvm, &invalid_list);
spin_unlock(&kvm->mmu_lock);
srcu_read_unlock(&kvm->srcu, idx);
+ /*
+ * unfair on small ones
+ * per-vm shrinkers cry out
+ * sadness comes quickly
+ */
list_move_tail(&kvm->vm_list, &vm_list);
break;
}
raw_spin_unlock(&kvm_lock);
+ return freed;
-out:
+}
+
+static long
+mmu_shrink_count(
+ struct shrinker *shrink,
+ struct shrink_control *sc)
+{
return percpu_counter_read_positive(&kvm_total_used_mmu_pages);
}
static struct shrinker mmu_shrinker = {
- .shrink = mmu_shrink,
+ .count_objects = mmu_shrink_count,
+ .scan_objects = mmu_shrink_scan,
.seeks = DEFAULT_SEEKS * 10,
};
diff --git a/net/sunrpc/auth.c b/net/sunrpc/auth.c
index ed2fdd2..9ce0976 100644
--- a/net/sunrpc/auth.c
+++ b/net/sunrpc/auth.c
@@ -413,12 +413,13 @@ EXPORT_SYMBOL_GPL(rpcauth_destroy_credcache);
/*
* Remove stale credentials. Avoid sleeping inside the loop.
*/
-static int
+static long
rpcauth_prune_expired(struct list_head *free, int nr_to_scan)
{
spinlock_t *cache_lock;
struct rpc_cred *cred, *next;
unsigned long expired = jiffies - RPC_AUTH_EXPIRY_MORATORIUM;
+ long freed = 0;
list_for_each_entry_safe(cred, next, &cred_unused, cr_lru) {
@@ -430,10 +431,11 @@ rpcauth_prune_expired(struct list_head *free, int nr_to_scan)
*/
if (time_in_range(cred->cr_expire, expired, jiffies) &&
test_bit(RPCAUTH_CRED_HASHED, &cred->cr_flags) != 0)
- return 0;
+ break;
list_del_init(&cred->cr_lru);
number_cred_unused--;
+ freed++;
if (atomic_read(&cred->cr_count) != 0)
continue;
@@ -446,29 +448,43 @@ rpcauth_prune_expired(struct list_head *free, int nr_to_scan)
}
spin_unlock(cache_lock);
}
- return (number_cred_unused / 100) * sysctl_vfs_cache_pressure;
+ return freed;
}
/*
* Run memory cache shrinker.
*/
-static int
-rpcauth_cache_shrinker(struct shrinker *shrink, struct shrink_control *sc)
+static long
+rpcauth_cache_shrink_scan(
+ struct shrinker *shrink,
+ struct shrink_control *sc)
+
{
LIST_HEAD(free);
- int res;
- int nr_to_scan = sc->nr_to_scan;
- gfp_t gfp_mask = sc->gfp_mask;
+ long freed;
+
+ if ((sc->gfp_mask & GFP_KERNEL) != GFP_KERNEL)
+ return -1;
- if ((gfp_mask & GFP_KERNEL) != GFP_KERNEL)
- return (nr_to_scan == 0) ? 0 : -1;
+ /* nothing left, don't come back */
if (list_empty(&cred_unused))
- return 0;
+ return -1;
+
spin_lock(&rpc_credcache_lock);
- res = rpcauth_prune_expired(&free, nr_to_scan);
+ freed = rpcauth_prune_expired(&free, sc->nr_to_scan);
spin_unlock(&rpc_credcache_lock);
rpcauth_destroy_credlist(&free);
- return res;
+
+ return freed;
+}
+
+static long
+rpcauth_cache_shrink_count(
+ struct shrinker *shrink,
+ struct shrink_control *sc)
+
+{
+ return (number_cred_unused / 100) * sysctl_vfs_cache_pressure;
}
/*
@@ -784,7 +800,8 @@ rpcauth_uptodatecred(struct rpc_task *task)
}
static struct shrinker rpc_cred_shrinker = {
- .shrink = rpcauth_cache_shrinker,
+ .count_objects = rpcauth_cache_shrink_count,
+ .scan_objects = rpcauth_cache_shrink_scan,
.seeks = DEFAULT_SEEKS,
};
--
1.8.1.4
^ permalink raw reply related [flat|nested] 151+ messages in thread* [PATCH v6 18/31] shrinker: convert remaining shrinkers to count/scan API
@ 2013-05-12 18:13 ` Glauber Costa
0 siblings, 0 replies; 151+ messages in thread
From: Glauber Costa @ 2013-05-12 18:13 UTC (permalink / raw)
To: linux-mm
Cc: cgroups, Andrew Morton, Greg Thelen, kamezawa.hiroyu,
Michal Hocko, Johannes Weiner, linux-fsdevel, Dave Chinner,
Dave Chinner, Glauber Costa, Marcelo Tosatti, Gleb Natapov,
Chuck Lever, J. Bruce Fields, Trond Myklebust
From: Dave Chinner <dchinner@redhat.com>
Convert the remaining couple of random shrinkers in the tree to the
new API.
Signed-off-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Glauber Costa <glommer@openvz.org>
CC: Marcelo Tosatti <mtosatti@redhat.com>
CC: Gleb Natapov <gleb@redhat.com>
CC: Chuck Lever <chuck.lever@oracle.com>
CC: J. Bruce Fields <bfields@redhat.com>
CC: Trond Myklebust <Trond.Myklebust@netapp.com>
---
arch/x86/kvm/mmu.c | 28 +++++++++++++++++++++-------
net/sunrpc/auth.c | 45 +++++++++++++++++++++++++++++++--------------
2 files changed, 52 insertions(+), 21 deletions(-)
diff --git a/arch/x86/kvm/mmu.c b/arch/x86/kvm/mmu.c
index 004cc87..19b4edf 100644
--- a/arch/x86/kvm/mmu.c
+++ b/arch/x86/kvm/mmu.c
@@ -4212,13 +4212,14 @@ restart:
spin_unlock(&kvm->mmu_lock);
}
-static int mmu_shrink(struct shrinker *shrink, struct shrink_control *sc)
+static long
+mmu_shrink_scan(
+ struct shrinker *shrink,
+ struct shrink_control *sc)
{
struct kvm *kvm;
int nr_to_scan = sc->nr_to_scan;
-
- if (nr_to_scan == 0)
- goto out;
+ long freed = 0;
raw_spin_lock(&kvm_lock);
@@ -4246,24 +4247,37 @@ static int mmu_shrink(struct shrinker *shrink, struct shrink_control *sc)
idx = srcu_read_lock(&kvm->srcu);
spin_lock(&kvm->mmu_lock);
- prepare_zap_oldest_mmu_page(kvm, &invalid_list);
+ freed += prepare_zap_oldest_mmu_page(kvm, &invalid_list);
kvm_mmu_commit_zap_page(kvm, &invalid_list);
spin_unlock(&kvm->mmu_lock);
srcu_read_unlock(&kvm->srcu, idx);
+ /*
+ * unfair on small ones
+ * per-vm shrinkers cry out
+ * sadness comes quickly
+ */
list_move_tail(&kvm->vm_list, &vm_list);
break;
}
raw_spin_unlock(&kvm_lock);
+ return freed;
-out:
+}
+
+static long
+mmu_shrink_count(
+ struct shrinker *shrink,
+ struct shrink_control *sc)
+{
return percpu_counter_read_positive(&kvm_total_used_mmu_pages);
}
static struct shrinker mmu_shrinker = {
- .shrink = mmu_shrink,
+ .count_objects = mmu_shrink_count,
+ .scan_objects = mmu_shrink_scan,
.seeks = DEFAULT_SEEKS * 10,
};
diff --git a/net/sunrpc/auth.c b/net/sunrpc/auth.c
index ed2fdd2..9ce0976 100644
--- a/net/sunrpc/auth.c
+++ b/net/sunrpc/auth.c
@@ -413,12 +413,13 @@ EXPORT_SYMBOL_GPL(rpcauth_destroy_credcache);
/*
* Remove stale credentials. Avoid sleeping inside the loop.
*/
-static int
+static long
rpcauth_prune_expired(struct list_head *free, int nr_to_scan)
{
spinlock_t *cache_lock;
struct rpc_cred *cred, *next;
unsigned long expired = jiffies - RPC_AUTH_EXPIRY_MORATORIUM;
+ long freed = 0;
list_for_each_entry_safe(cred, next, &cred_unused, cr_lru) {
@@ -430,10 +431,11 @@ rpcauth_prune_expired(struct list_head *free, int nr_to_scan)
*/
if (time_in_range(cred->cr_expire, expired, jiffies) &&
test_bit(RPCAUTH_CRED_HASHED, &cred->cr_flags) != 0)
- return 0;
+ break;
list_del_init(&cred->cr_lru);
number_cred_unused--;
+ freed++;
if (atomic_read(&cred->cr_count) != 0)
continue;
@@ -446,29 +448,43 @@ rpcauth_prune_expired(struct list_head *free, int nr_to_scan)
}
spin_unlock(cache_lock);
}
- return (number_cred_unused / 100) * sysctl_vfs_cache_pressure;
+ return freed;
}
/*
* Run memory cache shrinker.
*/
-static int
-rpcauth_cache_shrinker(struct shrinker *shrink, struct shrink_control *sc)
+static long
+rpcauth_cache_shrink_scan(
+ struct shrinker *shrink,
+ struct shrink_control *sc)
+
{
LIST_HEAD(free);
- int res;
- int nr_to_scan = sc->nr_to_scan;
- gfp_t gfp_mask = sc->gfp_mask;
+ long freed;
+
+ if ((sc->gfp_mask & GFP_KERNEL) != GFP_KERNEL)
+ return -1;
- if ((gfp_mask & GFP_KERNEL) != GFP_KERNEL)
- return (nr_to_scan == 0) ? 0 : -1;
+ /* nothing left, don't come back */
if (list_empty(&cred_unused))
- return 0;
+ return -1;
+
spin_lock(&rpc_credcache_lock);
- res = rpcauth_prune_expired(&free, nr_to_scan);
+ freed = rpcauth_prune_expired(&free, sc->nr_to_scan);
spin_unlock(&rpc_credcache_lock);
rpcauth_destroy_credlist(&free);
- return res;
+
+ return freed;
+}
+
+static long
+rpcauth_cache_shrink_count(
+ struct shrinker *shrink,
+ struct shrink_control *sc)
+
+{
+ return (number_cred_unused / 100) * sysctl_vfs_cache_pressure;
}
/*
@@ -784,7 +800,8 @@ rpcauth_uptodatecred(struct rpc_task *task)
}
static struct shrinker rpc_cred_shrinker = {
- .shrink = rpcauth_cache_shrinker,
+ .count_objects = rpcauth_cache_shrink_count,
+ .scan_objects = rpcauth_cache_shrink_scan,
.seeks = DEFAULT_SEEKS,
};
--
1.8.1.4
--
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^ permalink raw reply related [flat|nested] 151+ messages in thread
* [PATCH v6 19/31] hugepage: convert huge zero page shrinker to new shrinker API
2013-05-12 18:13 ` Glauber Costa
(?)
@ 2013-05-12 18:13 ` Glauber Costa
-1 siblings, 0 replies; 151+ messages in thread
From: Glauber Costa @ 2013-05-12 18:13 UTC (permalink / raw)
To: linux-mm
Cc: cgroups, Andrew Morton, Greg Thelen, kamezawa.hiroyu,
Michal Hocko, Johannes Weiner, linux-fsdevel, Dave Chinner,
Glauber Costa, Dave Chinner
It consists of:
* returning long instead of int
* separating count from scan
* returning the number of freed entities in scan
Signed-off-by: Glauber Costa <glommer@openvz.org>
Reviewed-by: Greg Thelen <gthelen@google.com>
Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
CC: Dave Chinner <dchinner@redhat.com>
---
mm/huge_memory.c | 17 +++++++++++------
1 file changed, 11 insertions(+), 6 deletions(-)
diff --git a/mm/huge_memory.c b/mm/huge_memory.c
index c5f2fa1..3a0eda8 100644
--- a/mm/huge_memory.c
+++ b/mm/huge_memory.c
@@ -211,24 +211,29 @@ static void put_huge_zero_page(void)
BUG_ON(atomic_dec_and_test(&huge_zero_refcount));
}
-static int shrink_huge_zero_page(struct shrinker *shrink,
- struct shrink_control *sc)
+static long shrink_huge_zero_page_count(struct shrinker *shrink,
+ struct shrink_control *sc)
{
- if (!sc->nr_to_scan)
- /* we can free zero page only if last reference remains */
- return atomic_read(&huge_zero_refcount) == 1 ? HPAGE_PMD_NR : 0;
+ /* we can free zero page only if last reference remains */
+ return atomic_read(&huge_zero_refcount) == 1 ? HPAGE_PMD_NR : 0;
+}
+static long shrink_huge_zero_page_scan(struct shrinker *shrink,
+ struct shrink_control *sc)
+{
if (atomic_cmpxchg(&huge_zero_refcount, 1, 0) == 1) {
struct page *zero_page = xchg(&huge_zero_page, NULL);
BUG_ON(zero_page == NULL);
__free_page(zero_page);
+ return HPAGE_PMD_NR;
}
return 0;
}
static struct shrinker huge_zero_page_shrinker = {
- .shrink = shrink_huge_zero_page,
+ .count_objects = shrink_huge_zero_page_count,
+ .scan_objects = shrink_huge_zero_page_scan,
.seeks = DEFAULT_SEEKS,
};
--
1.8.1.4
^ permalink raw reply related [flat|nested] 151+ messages in thread* [PATCH v6 19/31] hugepage: convert huge zero page shrinker to new shrinker API
@ 2013-05-12 18:13 ` Glauber Costa
0 siblings, 0 replies; 151+ messages in thread
From: Glauber Costa @ 2013-05-12 18:13 UTC (permalink / raw)
To: linux-mm
Cc: cgroups, Andrew Morton, Greg Thelen, kamezawa.hiroyu,
Michal Hocko, Johannes Weiner, linux-fsdevel, Dave Chinner,
Glauber Costa, Dave Chinner
It consists of:
* returning long instead of int
* separating count from scan
* returning the number of freed entities in scan
Signed-off-by: Glauber Costa <glommer@openvz.org>
Reviewed-by: Greg Thelen <gthelen@google.com>
Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
CC: Dave Chinner <dchinner@redhat.com>
---
mm/huge_memory.c | 17 +++++++++++------
1 file changed, 11 insertions(+), 6 deletions(-)
diff --git a/mm/huge_memory.c b/mm/huge_memory.c
index c5f2fa1..3a0eda8 100644
--- a/mm/huge_memory.c
+++ b/mm/huge_memory.c
@@ -211,24 +211,29 @@ static void put_huge_zero_page(void)
BUG_ON(atomic_dec_and_test(&huge_zero_refcount));
}
-static int shrink_huge_zero_page(struct shrinker *shrink,
- struct shrink_control *sc)
+static long shrink_huge_zero_page_count(struct shrinker *shrink,
+ struct shrink_control *sc)
{
- if (!sc->nr_to_scan)
- /* we can free zero page only if last reference remains */
- return atomic_read(&huge_zero_refcount) == 1 ? HPAGE_PMD_NR : 0;
+ /* we can free zero page only if last reference remains */
+ return atomic_read(&huge_zero_refcount) == 1 ? HPAGE_PMD_NR : 0;
+}
+static long shrink_huge_zero_page_scan(struct shrinker *shrink,
+ struct shrink_control *sc)
+{
if (atomic_cmpxchg(&huge_zero_refcount, 1, 0) == 1) {
struct page *zero_page = xchg(&huge_zero_page, NULL);
BUG_ON(zero_page == NULL);
__free_page(zero_page);
+ return HPAGE_PMD_NR;
}
return 0;
}
static struct shrinker huge_zero_page_shrinker = {
- .shrink = shrink_huge_zero_page,
+ .count_objects = shrink_huge_zero_page_count,
+ .scan_objects = shrink_huge_zero_page_scan,
.seeks = DEFAULT_SEEKS,
};
--
1.8.1.4
^ permalink raw reply related [flat|nested] 151+ messages in thread* [PATCH v6 19/31] hugepage: convert huge zero page shrinker to new shrinker API
@ 2013-05-12 18:13 ` Glauber Costa
0 siblings, 0 replies; 151+ messages in thread
From: Glauber Costa @ 2013-05-12 18:13 UTC (permalink / raw)
To: linux-mm
Cc: cgroups, Andrew Morton, Greg Thelen, kamezawa.hiroyu,
Michal Hocko, Johannes Weiner, linux-fsdevel, Dave Chinner,
Glauber Costa, Dave Chinner
It consists of:
* returning long instead of int
* separating count from scan
* returning the number of freed entities in scan
Signed-off-by: Glauber Costa <glommer@openvz.org>
Reviewed-by: Greg Thelen <gthelen@google.com>
Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
CC: Dave Chinner <dchinner@redhat.com>
---
mm/huge_memory.c | 17 +++++++++++------
1 file changed, 11 insertions(+), 6 deletions(-)
diff --git a/mm/huge_memory.c b/mm/huge_memory.c
index c5f2fa1..3a0eda8 100644
--- a/mm/huge_memory.c
+++ b/mm/huge_memory.c
@@ -211,24 +211,29 @@ static void put_huge_zero_page(void)
BUG_ON(atomic_dec_and_test(&huge_zero_refcount));
}
-static int shrink_huge_zero_page(struct shrinker *shrink,
- struct shrink_control *sc)
+static long shrink_huge_zero_page_count(struct shrinker *shrink,
+ struct shrink_control *sc)
{
- if (!sc->nr_to_scan)
- /* we can free zero page only if last reference remains */
- return atomic_read(&huge_zero_refcount) == 1 ? HPAGE_PMD_NR : 0;
+ /* we can free zero page only if last reference remains */
+ return atomic_read(&huge_zero_refcount) == 1 ? HPAGE_PMD_NR : 0;
+}
+static long shrink_huge_zero_page_scan(struct shrinker *shrink,
+ struct shrink_control *sc)
+{
if (atomic_cmpxchg(&huge_zero_refcount, 1, 0) == 1) {
struct page *zero_page = xchg(&huge_zero_page, NULL);
BUG_ON(zero_page == NULL);
__free_page(zero_page);
+ return HPAGE_PMD_NR;
}
return 0;
}
static struct shrinker huge_zero_page_shrinker = {
- .shrink = shrink_huge_zero_page,
+ .count_objects = shrink_huge_zero_page_count,
+ .scan_objects = shrink_huge_zero_page_scan,
.seeks = DEFAULT_SEEKS,
};
--
1.8.1.4
--
To unsubscribe, send a message with 'unsubscribe linux-mm' in
the body to majordomo@kvack.org. For more info on Linux MM,
see: http://www.linux-mm.org/ .
Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a>
^ permalink raw reply related [flat|nested] 151+ messages in thread
* [PATCH v6 20/31] shrinker: Kill old ->shrink API.
2013-05-12 18:13 ` Glauber Costa
(?)
@ 2013-05-12 18:13 ` Glauber Costa
-1 siblings, 0 replies; 151+ messages in thread
From: Glauber Costa @ 2013-05-12 18:13 UTC (permalink / raw)
To: linux-mm
Cc: cgroups, Andrew Morton, Greg Thelen, kamezawa.hiroyu,
Michal Hocko, Johannes Weiner, linux-fsdevel, Dave Chinner,
Dave Chinner, Glauber Costa
From: Dave Chinner <dchinner@redhat.com>
There are no more users of this API, so kill it dead, dead, dead and
quietly bury the corpse in a shallow, unmarked grave in a dark
forest deep in the hills...
[ glommer: added flowers to the grave ]
Signed-off-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Glauber Costa <glommer@openvz.org>
Reviewed-by: Greg Thelen <gthelen@google.com>
Acked-by: Mel Gorman <mgorman@suse.de>
---
include/linux/shrinker.h | 15 +++++----------
include/trace/events/vmscan.h | 4 ++--
mm/vmscan.c | 38 ++++++++------------------------------
3 files changed, 15 insertions(+), 42 deletions(-)
diff --git a/include/linux/shrinker.h b/include/linux/shrinker.h
index 98be3ab..00a3e57 100644
--- a/include/linux/shrinker.h
+++ b/include/linux/shrinker.h
@@ -7,14 +7,15 @@
*
* The 'gfpmask' refers to the allocation we are currently trying to
* fulfil.
- *
- * Note that 'shrink' will be passed nr_to_scan == 0 when the VM is
- * querying the cache size, so a fastpath for that case is appropriate.
*/
struct shrink_control {
gfp_t gfp_mask;
- /* How many slab objects shrinker() should scan and try to reclaim */
+ /*
+ * How many objects scan_objects should scan and try to reclaim.
+ * This is reset before every call, so it is safe for callees
+ * to modify.
+ */
long nr_to_scan;
/* shrink from these nodes */
@@ -24,11 +25,6 @@ struct shrink_control {
/*
* A callback you can register to apply pressure to ageable caches.
*
- * @shrink() should look through the least-recently-used 'nr_to_scan' entries
- * and attempt to free them up. It should return the number of objects which
- * remain in the cache. If it returns -1, it means it cannot do any scanning at
- * this time (eg. there is a risk of deadlock).
- *
* @count_objects should return the number of freeable items in the cache. If
* there are no objects to free or the number of freeable items cannot be
* determined, it should return 0. No deadlock checks should be done during the
@@ -44,7 +40,6 @@ struct shrink_control {
* @scan_objects will be made from the current reclaim context.
*/
struct shrinker {
- int (*shrink)(struct shrinker *, struct shrink_control *sc);
long (*count_objects)(struct shrinker *, struct shrink_control *sc);
long (*scan_objects)(struct shrinker *, struct shrink_control *sc);
diff --git a/include/trace/events/vmscan.h b/include/trace/events/vmscan.h
index 63cfccc..132a985 100644
--- a/include/trace/events/vmscan.h
+++ b/include/trace/events/vmscan.h
@@ -202,7 +202,7 @@ TRACE_EVENT(mm_shrink_slab_start,
TP_fast_assign(
__entry->shr = shr;
- __entry->shrink = shr->shrink;
+ __entry->shrink = shr->scan_objects;
__entry->nr_objects_to_shrink = nr_objects_to_shrink;
__entry->gfp_flags = sc->gfp_mask;
__entry->pgs_scanned = pgs_scanned;
@@ -241,7 +241,7 @@ TRACE_EVENT(mm_shrink_slab_end,
TP_fast_assign(
__entry->shr = shr;
- __entry->shrink = shr->shrink;
+ __entry->shrink = shr->scan_objects;
__entry->unused_scan = unused_scan_cnt;
__entry->new_scan = new_scan_cnt;
__entry->retval = shrinker_retval;
diff --git a/mm/vmscan.c b/mm/vmscan.c
index 35a6a9b..64f66f6 100644
--- a/mm/vmscan.c
+++ b/mm/vmscan.c
@@ -177,14 +177,6 @@ void unregister_shrinker(struct shrinker *shrinker)
}
EXPORT_SYMBOL(unregister_shrinker);
-static inline int do_shrinker_shrink(struct shrinker *shrinker,
- struct shrink_control *sc,
- unsigned long nr_to_scan)
-{
- sc->nr_to_scan = nr_to_scan;
- return (*shrinker->shrink)(shrinker, sc);
-}
-
#define SHRINK_BATCH 128
/*
* Call the shrink functions to age shrinkable caches
@@ -230,11 +222,8 @@ unsigned long shrink_slab(struct shrink_control *shrinkctl,
long batch_size = shrinker->batch ? shrinker->batch
: SHRINK_BATCH;
- if (shrinker->scan_objects) {
- max_pass = shrinker->count_objects(shrinker, shrinkctl);
- WARN_ON(max_pass < 0);
- } else
- max_pass = do_shrinker_shrink(shrinker, shrinkctl, 0);
+ max_pass = shrinker->count_objects(shrinker, shrinkctl);
+ WARN_ON(max_pass < 0);
if (max_pass <= 0)
continue;
@@ -253,7 +242,7 @@ unsigned long shrink_slab(struct shrink_control *shrinkctl,
if (total_scan < 0) {
printk(KERN_ERR
"shrink_slab: %pF negative objects to delete nr=%ld\n",
- shrinker->shrink, total_scan);
+ shrinker->scan_objects, total_scan);
total_scan = max_pass;
}
@@ -287,23 +276,12 @@ unsigned long shrink_slab(struct shrink_control *shrinkctl,
while (total_scan >= batch_size) {
long ret;
- if (shrinker->scan_objects) {
- shrinkctl->nr_to_scan = batch_size;
- ret = shrinker->scan_objects(shrinker, shrinkctl);
+ shrinkctl->nr_to_scan = batch_size;
+ ret = shrinker->scan_objects(shrinker, shrinkctl);
- if (ret == -1)
- break;
- freed += ret;
- } else {
- int nr_before;
- nr_before = do_shrinker_shrink(shrinker, shrinkctl, 0);
- ret = do_shrinker_shrink(shrinker, shrinkctl,
- batch_size);
- if (ret == -1)
- break;
- if (ret < nr_before)
- freed += nr_before - ret;
- }
+ if (ret == -1)
+ break;
+ freed += ret;
count_vm_events(SLABS_SCANNED, batch_size);
total_scan -= batch_size;
--
1.8.1.4
^ permalink raw reply related [flat|nested] 151+ messages in thread* [PATCH v6 20/31] shrinker: Kill old ->shrink API.
@ 2013-05-12 18:13 ` Glauber Costa
0 siblings, 0 replies; 151+ messages in thread
From: Glauber Costa @ 2013-05-12 18:13 UTC (permalink / raw)
To: linux-mm
Cc: cgroups, Andrew Morton, Greg Thelen, kamezawa.hiroyu,
Michal Hocko, Johannes Weiner, linux-fsdevel, Dave Chinner,
Dave Chinner, Glauber Costa
From: Dave Chinner <dchinner@redhat.com>
There are no more users of this API, so kill it dead, dead, dead and
quietly bury the corpse in a shallow, unmarked grave in a dark
forest deep in the hills...
[ glommer: added flowers to the grave ]
Signed-off-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Glauber Costa <glommer@openvz.org>
Reviewed-by: Greg Thelen <gthelen@google.com>
Acked-by: Mel Gorman <mgorman@suse.de>
---
include/linux/shrinker.h | 15 +++++----------
include/trace/events/vmscan.h | 4 ++--
mm/vmscan.c | 38 ++++++++------------------------------
3 files changed, 15 insertions(+), 42 deletions(-)
diff --git a/include/linux/shrinker.h b/include/linux/shrinker.h
index 98be3ab..00a3e57 100644
--- a/include/linux/shrinker.h
+++ b/include/linux/shrinker.h
@@ -7,14 +7,15 @@
*
* The 'gfpmask' refers to the allocation we are currently trying to
* fulfil.
- *
- * Note that 'shrink' will be passed nr_to_scan == 0 when the VM is
- * querying the cache size, so a fastpath for that case is appropriate.
*/
struct shrink_control {
gfp_t gfp_mask;
- /* How many slab objects shrinker() should scan and try to reclaim */
+ /*
+ * How many objects scan_objects should scan and try to reclaim.
+ * This is reset before every call, so it is safe for callees
+ * to modify.
+ */
long nr_to_scan;
/* shrink from these nodes */
@@ -24,11 +25,6 @@ struct shrink_control {
/*
* A callback you can register to apply pressure to ageable caches.
*
- * @shrink() should look through the least-recently-used 'nr_to_scan' entries
- * and attempt to free them up. It should return the number of objects which
- * remain in the cache. If it returns -1, it means it cannot do any scanning at
- * this time (eg. there is a risk of deadlock).
- *
* @count_objects should return the number of freeable items in the cache. If
* there are no objects to free or the number of freeable items cannot be
* determined, it should return 0. No deadlock checks should be done during the
@@ -44,7 +40,6 @@ struct shrink_control {
* @scan_objects will be made from the current reclaim context.
*/
struct shrinker {
- int (*shrink)(struct shrinker *, struct shrink_control *sc);
long (*count_objects)(struct shrinker *, struct shrink_control *sc);
long (*scan_objects)(struct shrinker *, struct shrink_control *sc);
diff --git a/include/trace/events/vmscan.h b/include/trace/events/vmscan.h
index 63cfccc..132a985 100644
--- a/include/trace/events/vmscan.h
+++ b/include/trace/events/vmscan.h
@@ -202,7 +202,7 @@ TRACE_EVENT(mm_shrink_slab_start,
TP_fast_assign(
__entry->shr = shr;
- __entry->shrink = shr->shrink;
+ __entry->shrink = shr->scan_objects;
__entry->nr_objects_to_shrink = nr_objects_to_shrink;
__entry->gfp_flags = sc->gfp_mask;
__entry->pgs_scanned = pgs_scanned;
@@ -241,7 +241,7 @@ TRACE_EVENT(mm_shrink_slab_end,
TP_fast_assign(
__entry->shr = shr;
- __entry->shrink = shr->shrink;
+ __entry->shrink = shr->scan_objects;
__entry->unused_scan = unused_scan_cnt;
__entry->new_scan = new_scan_cnt;
__entry->retval = shrinker_retval;
diff --git a/mm/vmscan.c b/mm/vmscan.c
index 35a6a9b..64f66f6 100644
--- a/mm/vmscan.c
+++ b/mm/vmscan.c
@@ -177,14 +177,6 @@ void unregister_shrinker(struct shrinker *shrinker)
}
EXPORT_SYMBOL(unregister_shrinker);
-static inline int do_shrinker_shrink(struct shrinker *shrinker,
- struct shrink_control *sc,
- unsigned long nr_to_scan)
-{
- sc->nr_to_scan = nr_to_scan;
- return (*shrinker->shrink)(shrinker, sc);
-}
-
#define SHRINK_BATCH 128
/*
* Call the shrink functions to age shrinkable caches
@@ -230,11 +222,8 @@ unsigned long shrink_slab(struct shrink_control *shrinkctl,
long batch_size = shrinker->batch ? shrinker->batch
: SHRINK_BATCH;
- if (shrinker->scan_objects) {
- max_pass = shrinker->count_objects(shrinker, shrinkctl);
- WARN_ON(max_pass < 0);
- } else
- max_pass = do_shrinker_shrink(shrinker, shrinkctl, 0);
+ max_pass = shrinker->count_objects(shrinker, shrinkctl);
+ WARN_ON(max_pass < 0);
if (max_pass <= 0)
continue;
@@ -253,7 +242,7 @@ unsigned long shrink_slab(struct shrink_control *shrinkctl,
if (total_scan < 0) {
printk(KERN_ERR
"shrink_slab: %pF negative objects to delete nr=%ld\n",
- shrinker->shrink, total_scan);
+ shrinker->scan_objects, total_scan);
total_scan = max_pass;
}
@@ -287,23 +276,12 @@ unsigned long shrink_slab(struct shrink_control *shrinkctl,
while (total_scan >= batch_size) {
long ret;
- if (shrinker->scan_objects) {
- shrinkctl->nr_to_scan = batch_size;
- ret = shrinker->scan_objects(shrinker, shrinkctl);
+ shrinkctl->nr_to_scan = batch_size;
+ ret = shrinker->scan_objects(shrinker, shrinkctl);
- if (ret == -1)
- break;
- freed += ret;
- } else {
- int nr_before;
- nr_before = do_shrinker_shrink(shrinker, shrinkctl, 0);
- ret = do_shrinker_shrink(shrinker, shrinkctl,
- batch_size);
- if (ret == -1)
- break;
- if (ret < nr_before)
- freed += nr_before - ret;
- }
+ if (ret == -1)
+ break;
+ freed += ret;
count_vm_events(SLABS_SCANNED, batch_size);
total_scan -= batch_size;
--
1.8.1.4
^ permalink raw reply related [flat|nested] 151+ messages in thread* [PATCH v6 20/31] shrinker: Kill old ->shrink API.
@ 2013-05-12 18:13 ` Glauber Costa
0 siblings, 0 replies; 151+ messages in thread
From: Glauber Costa @ 2013-05-12 18:13 UTC (permalink / raw)
To: linux-mm
Cc: cgroups, Andrew Morton, Greg Thelen, kamezawa.hiroyu,
Michal Hocko, Johannes Weiner, linux-fsdevel, Dave Chinner,
Dave Chinner, Glauber Costa
From: Dave Chinner <dchinner@redhat.com>
There are no more users of this API, so kill it dead, dead, dead and
quietly bury the corpse in a shallow, unmarked grave in a dark
forest deep in the hills...
[ glommer: added flowers to the grave ]
Signed-off-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Glauber Costa <glommer@openvz.org>
Reviewed-by: Greg Thelen <gthelen@google.com>
Acked-by: Mel Gorman <mgorman@suse.de>
---
include/linux/shrinker.h | 15 +++++----------
include/trace/events/vmscan.h | 4 ++--
mm/vmscan.c | 38 ++++++++------------------------------
3 files changed, 15 insertions(+), 42 deletions(-)
diff --git a/include/linux/shrinker.h b/include/linux/shrinker.h
index 98be3ab..00a3e57 100644
--- a/include/linux/shrinker.h
+++ b/include/linux/shrinker.h
@@ -7,14 +7,15 @@
*
* The 'gfpmask' refers to the allocation we are currently trying to
* fulfil.
- *
- * Note that 'shrink' will be passed nr_to_scan == 0 when the VM is
- * querying the cache size, so a fastpath for that case is appropriate.
*/
struct shrink_control {
gfp_t gfp_mask;
- /* How many slab objects shrinker() should scan and try to reclaim */
+ /*
+ * How many objects scan_objects should scan and try to reclaim.
+ * This is reset before every call, so it is safe for callees
+ * to modify.
+ */
long nr_to_scan;
/* shrink from these nodes */
@@ -24,11 +25,6 @@ struct shrink_control {
/*
* A callback you can register to apply pressure to ageable caches.
*
- * @shrink() should look through the least-recently-used 'nr_to_scan' entries
- * and attempt to free them up. It should return the number of objects which
- * remain in the cache. If it returns -1, it means it cannot do any scanning at
- * this time (eg. there is a risk of deadlock).
- *
* @count_objects should return the number of freeable items in the cache. If
* there are no objects to free or the number of freeable items cannot be
* determined, it should return 0. No deadlock checks should be done during the
@@ -44,7 +40,6 @@ struct shrink_control {
* @scan_objects will be made from the current reclaim context.
*/
struct shrinker {
- int (*shrink)(struct shrinker *, struct shrink_control *sc);
long (*count_objects)(struct shrinker *, struct shrink_control *sc);
long (*scan_objects)(struct shrinker *, struct shrink_control *sc);
diff --git a/include/trace/events/vmscan.h b/include/trace/events/vmscan.h
index 63cfccc..132a985 100644
--- a/include/trace/events/vmscan.h
+++ b/include/trace/events/vmscan.h
@@ -202,7 +202,7 @@ TRACE_EVENT(mm_shrink_slab_start,
TP_fast_assign(
__entry->shr = shr;
- __entry->shrink = shr->shrink;
+ __entry->shrink = shr->scan_objects;
__entry->nr_objects_to_shrink = nr_objects_to_shrink;
__entry->gfp_flags = sc->gfp_mask;
__entry->pgs_scanned = pgs_scanned;
@@ -241,7 +241,7 @@ TRACE_EVENT(mm_shrink_slab_end,
TP_fast_assign(
__entry->shr = shr;
- __entry->shrink = shr->shrink;
+ __entry->shrink = shr->scan_objects;
__entry->unused_scan = unused_scan_cnt;
__entry->new_scan = new_scan_cnt;
__entry->retval = shrinker_retval;
diff --git a/mm/vmscan.c b/mm/vmscan.c
index 35a6a9b..64f66f6 100644
--- a/mm/vmscan.c
+++ b/mm/vmscan.c
@@ -177,14 +177,6 @@ void unregister_shrinker(struct shrinker *shrinker)
}
EXPORT_SYMBOL(unregister_shrinker);
-static inline int do_shrinker_shrink(struct shrinker *shrinker,
- struct shrink_control *sc,
- unsigned long nr_to_scan)
-{
- sc->nr_to_scan = nr_to_scan;
- return (*shrinker->shrink)(shrinker, sc);
-}
-
#define SHRINK_BATCH 128
/*
* Call the shrink functions to age shrinkable caches
@@ -230,11 +222,8 @@ unsigned long shrink_slab(struct shrink_control *shrinkctl,
long batch_size = shrinker->batch ? shrinker->batch
: SHRINK_BATCH;
- if (shrinker->scan_objects) {
- max_pass = shrinker->count_objects(shrinker, shrinkctl);
- WARN_ON(max_pass < 0);
- } else
- max_pass = do_shrinker_shrink(shrinker, shrinkctl, 0);
+ max_pass = shrinker->count_objects(shrinker, shrinkctl);
+ WARN_ON(max_pass < 0);
if (max_pass <= 0)
continue;
@@ -253,7 +242,7 @@ unsigned long shrink_slab(struct shrink_control *shrinkctl,
if (total_scan < 0) {
printk(KERN_ERR
"shrink_slab: %pF negative objects to delete nr=%ld\n",
- shrinker->shrink, total_scan);
+ shrinker->scan_objects, total_scan);
total_scan = max_pass;
}
@@ -287,23 +276,12 @@ unsigned long shrink_slab(struct shrink_control *shrinkctl,
while (total_scan >= batch_size) {
long ret;
- if (shrinker->scan_objects) {
- shrinkctl->nr_to_scan = batch_size;
- ret = shrinker->scan_objects(shrinker, shrinkctl);
+ shrinkctl->nr_to_scan = batch_size;
+ ret = shrinker->scan_objects(shrinker, shrinkctl);
- if (ret == -1)
- break;
- freed += ret;
- } else {
- int nr_before;
- nr_before = do_shrinker_shrink(shrinker, shrinkctl, 0);
- ret = do_shrinker_shrink(shrinker, shrinkctl,
- batch_size);
- if (ret == -1)
- break;
- if (ret < nr_before)
- freed += nr_before - ret;
- }
+ if (ret == -1)
+ break;
+ freed += ret;
count_vm_events(SLABS_SCANNED, batch_size);
total_scan -= batch_size;
--
1.8.1.4
--
To unsubscribe, send a message with 'unsubscribe linux-mm' in
the body to majordomo@kvack.org. For more info on Linux MM,
see: http://www.linux-mm.org/ .
Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a>
^ permalink raw reply related [flat|nested] 151+ messages in thread
* [PATCH v6 21/31] vmscan: also shrink slab in memcg pressure
2013-05-12 18:13 ` Glauber Costa
(?)
@ 2013-05-12 18:13 ` Glauber Costa
-1 siblings, 0 replies; 151+ messages in thread
From: Glauber Costa @ 2013-05-12 18:13 UTC (permalink / raw)
To: linux-mm
Cc: cgroups, Andrew Morton, Greg Thelen, kamezawa.hiroyu,
Michal Hocko, Johannes Weiner, linux-fsdevel, Dave Chinner,
Glauber Costa, Dave Chinner, Mel Gorman, Rik van Riel,
Hugh Dickins
Without the surrounding infrastructure, this patch is a bit of a hammer:
it will basically shrink objects from all memcgs under memcg pressure.
At least, however, we will keep the scan limited to the shrinkers marked
as per-memcg.
Future patches will implement the in-shrinker logic to filter objects
based on its memcg association.
Signed-off-by: Glauber Costa <glommer@openvz.org>
Cc: Dave Chinner <dchinner@redhat.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Rik van Riel <riel@redhat.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Michal Hocko <mhocko@suse.cz>
Cc: Hugh Dickins <hughd@google.com>
Cc: Kamezawa Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
---
include/linux/memcontrol.h | 17 +++++++++++++++++
include/linux/shrinker.h | 4 ++++
mm/memcontrol.c | 16 +++++++++++++++-
mm/vmscan.c | 46 +++++++++++++++++++++++++++++++++++++++++++---
4 files changed, 79 insertions(+), 4 deletions(-)
diff --git a/include/linux/memcontrol.h b/include/linux/memcontrol.h
index 7b4d9d7..489c6d7 100644
--- a/include/linux/memcontrol.h
+++ b/include/linux/memcontrol.h
@@ -200,6 +200,9 @@ void mem_cgroup_split_huge_fixup(struct page *head);
bool mem_cgroup_bad_page_check(struct page *page);
void mem_cgroup_print_bad_page(struct page *page);
#endif
+
+unsigned long
+memcg_zone_reclaimable_pages(struct mem_cgroup *memcg, struct zone *zone);
#else /* CONFIG_MEMCG */
struct mem_cgroup;
@@ -378,6 +381,12 @@ static inline void mem_cgroup_replace_page_cache(struct page *oldpage,
struct page *newpage)
{
}
+
+static inline unsigned long
+memcg_zone_reclaimable_pages(struct mem_cgroup *memcg, struct zone *zone)
+{
+ return 0;
+}
#endif /* CONFIG_MEMCG */
#if !defined(CONFIG_MEMCG) || !defined(CONFIG_DEBUG_VM)
@@ -430,6 +439,8 @@ static inline bool memcg_kmem_enabled(void)
return static_key_false(&memcg_kmem_enabled_key);
}
+bool memcg_kmem_is_active(struct mem_cgroup *memcg);
+
/*
* In general, we'll do everything in our power to not incur in any overhead
* for non-memcg users for the kmem functions. Not even a function call, if we
@@ -563,6 +574,12 @@ memcg_kmem_get_cache(struct kmem_cache *cachep, gfp_t gfp)
return __memcg_kmem_get_cache(cachep, gfp);
}
#else
+
+static inline bool memcg_kmem_is_active(struct mem_cgroup *memcg)
+{
+ return false;
+}
+
#define for_each_memcg_cache_index(_idx) \
for (; NULL; )
diff --git a/include/linux/shrinker.h b/include/linux/shrinker.h
index 00a3e57..3b08869 100644
--- a/include/linux/shrinker.h
+++ b/include/linux/shrinker.h
@@ -20,6 +20,9 @@ struct shrink_control {
/* shrink from these nodes */
nodemask_t nodes_to_scan;
+
+ /* reclaim from this memcg only (if not NULL) */
+ struct mem_cgroup *target_mem_cgroup;
};
/*
@@ -45,6 +48,7 @@ struct shrinker {
int seeks; /* seeks to recreate an obj */
long batch; /* reclaim batch size, 0 = default */
+ bool memcg_shrinker; /* memcg-aware shrinker */
/* These are for internal use */
struct list_head list;
diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index e34da3c..980bd2d 100644
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -465,7 +465,7 @@ static inline void memcg_kmem_set_active(struct mem_cgroup *memcg)
set_bit(KMEM_ACCOUNTED_ACTIVE, &memcg->kmem_account_flags);
}
-static bool memcg_kmem_is_active(struct mem_cgroup *memcg)
+bool memcg_kmem_is_active(struct mem_cgroup *memcg)
{
return test_bit(KMEM_ACCOUNTED_ACTIVE, &memcg->kmem_account_flags);
}
@@ -1044,6 +1044,20 @@ mem_cgroup_zone_nr_lru_pages(struct mem_cgroup *memcg, int nid, int zid,
return ret;
}
+unsigned long
+memcg_zone_reclaimable_pages(struct mem_cgroup *memcg, struct zone *zone)
+{
+ int nid = zone_to_nid(zone);
+ int zid = zone_idx(zone);
+ unsigned long val;
+
+ val = mem_cgroup_zone_nr_lru_pages(memcg, nid, zid, LRU_ALL_FILE);
+ if (do_swap_account)
+ val += mem_cgroup_zone_nr_lru_pages(memcg, nid, zid,
+ LRU_ALL_ANON);
+ return val;
+}
+
static unsigned long
mem_cgroup_node_nr_lru_pages(struct mem_cgroup *memcg,
int nid, unsigned int lru_mask)
diff --git a/mm/vmscan.c b/mm/vmscan.c
index 64f66f6..eb5e67c 100644
--- a/mm/vmscan.c
+++ b/mm/vmscan.c
@@ -139,11 +139,42 @@ static bool global_reclaim(struct scan_control *sc)
{
return !sc->target_mem_cgroup;
}
+
+/*
+ * kmem reclaim should usually not be triggered when we are doing targetted
+ * reclaim. It is only valid when global reclaim is triggered, or when the
+ * underlying memcg has kmem objects.
+ */
+static bool has_kmem_reclaim(struct scan_control *sc)
+{
+ return !sc->target_mem_cgroup ||
+ memcg_kmem_is_active(sc->target_mem_cgroup);
+}
+
+static unsigned long
+zone_nr_reclaimable_pages(struct scan_control *sc, struct zone *zone)
+{
+ if (global_reclaim(sc))
+ return zone_reclaimable_pages(zone);
+ return memcg_zone_reclaimable_pages(sc->target_mem_cgroup, zone);
+}
+
#else
static bool global_reclaim(struct scan_control *sc)
{
return true;
}
+
+static bool has_kmem_reclaim(struct scan_control *sc)
+{
+ return true;
+}
+
+static unsigned long
+zone_nr_reclaimable_pages(struct scan_control *sc, struct zone *zone)
+{
+ return zone_reclaimable_pages(zone);
+}
#endif
static unsigned long get_lru_size(struct lruvec *lruvec, enum lru_list lru)
@@ -222,6 +253,14 @@ unsigned long shrink_slab(struct shrink_control *shrinkctl,
long batch_size = shrinker->batch ? shrinker->batch
: SHRINK_BATCH;
+ /*
+ * If we don't have a target mem cgroup, we scan them all.
+ * Otherwise we will limit our scan to shrinkers marked as
+ * memcg aware
+ */
+ if (shrinkctl->target_mem_cgroup && !shrinker->memcg_shrinker)
+ continue;
+
max_pass = shrinker->count_objects(shrinker, shrinkctl);
WARN_ON(max_pass < 0);
if (max_pass <= 0)
@@ -2172,9 +2211,9 @@ static unsigned long do_try_to_free_pages(struct zonelist *zonelist,
/*
* Don't shrink slabs when reclaiming memory from
- * over limit cgroups
+ * over limit cgroups, unless we know they have kmem objects
*/
- if (global_reclaim(sc)) {
+ if (has_kmem_reclaim(sc)) {
unsigned long lru_pages = 0;
nodes_clear(shrink->nodes_to_scan);
@@ -2183,7 +2222,7 @@ static unsigned long do_try_to_free_pages(struct zonelist *zonelist,
if (!cpuset_zone_allowed_hardwall(zone, GFP_KERNEL))
continue;
- lru_pages += zone_reclaimable_pages(zone);
+ lru_pages += zone_nr_reclaimable_pages(sc, zone);
node_set(zone_to_nid(zone),
shrink->nodes_to_scan);
}
@@ -2452,6 +2491,7 @@ unsigned long try_to_free_mem_cgroup_pages(struct mem_cgroup *memcg,
};
struct shrink_control shrink = {
.gfp_mask = sc.gfp_mask,
+ .target_mem_cgroup = memcg,
};
/*
--
1.8.1.4
^ permalink raw reply related [flat|nested] 151+ messages in thread* [PATCH v6 21/31] vmscan: also shrink slab in memcg pressure
@ 2013-05-12 18:13 ` Glauber Costa
0 siblings, 0 replies; 151+ messages in thread
From: Glauber Costa @ 2013-05-12 18:13 UTC (permalink / raw)
To: linux-mm
Cc: cgroups, Andrew Morton, Greg Thelen, kamezawa.hiroyu,
Michal Hocko, Johannes Weiner, linux-fsdevel, Dave Chinner,
Glauber Costa, Dave Chinner, Mel Gorman, Rik van Riel,
Hugh Dickins
Without the surrounding infrastructure, this patch is a bit of a hammer:
it will basically shrink objects from all memcgs under memcg pressure.
At least, however, we will keep the scan limited to the shrinkers marked
as per-memcg.
Future patches will implement the in-shrinker logic to filter objects
based on its memcg association.
Signed-off-by: Glauber Costa <glommer@openvz.org>
Cc: Dave Chinner <dchinner@redhat.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Rik van Riel <riel@redhat.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Michal Hocko <mhocko@suse.cz>
Cc: Hugh Dickins <hughd@google.com>
Cc: Kamezawa Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
---
include/linux/memcontrol.h | 17 +++++++++++++++++
include/linux/shrinker.h | 4 ++++
mm/memcontrol.c | 16 +++++++++++++++-
mm/vmscan.c | 46 +++++++++++++++++++++++++++++++++++++++++++---
4 files changed, 79 insertions(+), 4 deletions(-)
diff --git a/include/linux/memcontrol.h b/include/linux/memcontrol.h
index 7b4d9d7..489c6d7 100644
--- a/include/linux/memcontrol.h
+++ b/include/linux/memcontrol.h
@@ -200,6 +200,9 @@ void mem_cgroup_split_huge_fixup(struct page *head);
bool mem_cgroup_bad_page_check(struct page *page);
void mem_cgroup_print_bad_page(struct page *page);
#endif
+
+unsigned long
+memcg_zone_reclaimable_pages(struct mem_cgroup *memcg, struct zone *zone);
#else /* CONFIG_MEMCG */
struct mem_cgroup;
@@ -378,6 +381,12 @@ static inline void mem_cgroup_replace_page_cache(struct page *oldpage,
struct page *newpage)
{
}
+
+static inline unsigned long
+memcg_zone_reclaimable_pages(struct mem_cgroup *memcg, struct zone *zone)
+{
+ return 0;
+}
#endif /* CONFIG_MEMCG */
#if !defined(CONFIG_MEMCG) || !defined(CONFIG_DEBUG_VM)
@@ -430,6 +439,8 @@ static inline bool memcg_kmem_enabled(void)
return static_key_false(&memcg_kmem_enabled_key);
}
+bool memcg_kmem_is_active(struct mem_cgroup *memcg);
+
/*
* In general, we'll do everything in our power to not incur in any overhead
* for non-memcg users for the kmem functions. Not even a function call, if we
@@ -563,6 +574,12 @@ memcg_kmem_get_cache(struct kmem_cache *cachep, gfp_t gfp)
return __memcg_kmem_get_cache(cachep, gfp);
}
#else
+
+static inline bool memcg_kmem_is_active(struct mem_cgroup *memcg)
+{
+ return false;
+}
+
#define for_each_memcg_cache_index(_idx) \
for (; NULL; )
diff --git a/include/linux/shrinker.h b/include/linux/shrinker.h
index 00a3e57..3b08869 100644
--- a/include/linux/shrinker.h
+++ b/include/linux/shrinker.h
@@ -20,6 +20,9 @@ struct shrink_control {
/* shrink from these nodes */
nodemask_t nodes_to_scan;
+
+ /* reclaim from this memcg only (if not NULL) */
+ struct mem_cgroup *target_mem_cgroup;
};
/*
@@ -45,6 +48,7 @@ struct shrinker {
int seeks; /* seeks to recreate an obj */
long batch; /* reclaim batch size, 0 = default */
+ bool memcg_shrinker; /* memcg-aware shrinker */
/* These are for internal use */
struct list_head list;
diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index e34da3c..980bd2d 100644
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -465,7 +465,7 @@ static inline void memcg_kmem_set_active(struct mem_cgroup *memcg)
set_bit(KMEM_ACCOUNTED_ACTIVE, &memcg->kmem_account_flags);
}
-static bool memcg_kmem_is_active(struct mem_cgroup *memcg)
+bool memcg_kmem_is_active(struct mem_cgroup *memcg)
{
return test_bit(KMEM_ACCOUNTED_ACTIVE, &memcg->kmem_account_flags);
}
@@ -1044,6 +1044,20 @@ mem_cgroup_zone_nr_lru_pages(struct mem_cgroup *memcg, int nid, int zid,
return ret;
}
+unsigned long
+memcg_zone_reclaimable_pages(struct mem_cgroup *memcg, struct zone *zone)
+{
+ int nid = zone_to_nid(zone);
+ int zid = zone_idx(zone);
+ unsigned long val;
+
+ val = mem_cgroup_zone_nr_lru_pages(memcg, nid, zid, LRU_ALL_FILE);
+ if (do_swap_account)
+ val += mem_cgroup_zone_nr_lru_pages(memcg, nid, zid,
+ LRU_ALL_ANON);
+ return val;
+}
+
static unsigned long
mem_cgroup_node_nr_lru_pages(struct mem_cgroup *memcg,
int nid, unsigned int lru_mask)
diff --git a/mm/vmscan.c b/mm/vmscan.c
index 64f66f6..eb5e67c 100644
--- a/mm/vmscan.c
+++ b/mm/vmscan.c
@@ -139,11 +139,42 @@ static bool global_reclaim(struct scan_control *sc)
{
return !sc->target_mem_cgroup;
}
+
+/*
+ * kmem reclaim should usually not be triggered when we are doing targetted
+ * reclaim. It is only valid when global reclaim is triggered, or when the
+ * underlying memcg has kmem objects.
+ */
+static bool has_kmem_reclaim(struct scan_control *sc)
+{
+ return !sc->target_mem_cgroup ||
+ memcg_kmem_is_active(sc->target_mem_cgroup);
+}
+
+static unsigned long
+zone_nr_reclaimable_pages(struct scan_control *sc, struct zone *zone)
+{
+ if (global_reclaim(sc))
+ return zone_reclaimable_pages(zone);
+ return memcg_zone_reclaimable_pages(sc->target_mem_cgroup, zone);
+}
+
#else
static bool global_reclaim(struct scan_control *sc)
{
return true;
}
+
+static bool has_kmem_reclaim(struct scan_control *sc)
+{
+ return true;
+}
+
+static unsigned long
+zone_nr_reclaimable_pages(struct scan_control *sc, struct zone *zone)
+{
+ return zone_reclaimable_pages(zone);
+}
#endif
static unsigned long get_lru_size(struct lruvec *lruvec, enum lru_list lru)
@@ -222,6 +253,14 @@ unsigned long shrink_slab(struct shrink_control *shrinkctl,
long batch_size = shrinker->batch ? shrinker->batch
: SHRINK_BATCH;
+ /*
+ * If we don't have a target mem cgroup, we scan them all.
+ * Otherwise we will limit our scan to shrinkers marked as
+ * memcg aware
+ */
+ if (shrinkctl->target_mem_cgroup && !shrinker->memcg_shrinker)
+ continue;
+
max_pass = shrinker->count_objects(shrinker, shrinkctl);
WARN_ON(max_pass < 0);
if (max_pass <= 0)
@@ -2172,9 +2211,9 @@ static unsigned long do_try_to_free_pages(struct zonelist *zonelist,
/*
* Don't shrink slabs when reclaiming memory from
- * over limit cgroups
+ * over limit cgroups, unless we know they have kmem objects
*/
- if (global_reclaim(sc)) {
+ if (has_kmem_reclaim(sc)) {
unsigned long lru_pages = 0;
nodes_clear(shrink->nodes_to_scan);
@@ -2183,7 +2222,7 @@ static unsigned long do_try_to_free_pages(struct zonelist *zonelist,
if (!cpuset_zone_allowed_hardwall(zone, GFP_KERNEL))
continue;
- lru_pages += zone_reclaimable_pages(zone);
+ lru_pages += zone_nr_reclaimable_pages(sc, zone);
node_set(zone_to_nid(zone),
shrink->nodes_to_scan);
}
@@ -2452,6 +2491,7 @@ unsigned long try_to_free_mem_cgroup_pages(struct mem_cgroup *memcg,
};
struct shrink_control shrink = {
.gfp_mask = sc.gfp_mask,
+ .target_mem_cgroup = memcg,
};
/*
--
1.8.1.4
^ permalink raw reply related [flat|nested] 151+ messages in thread* [PATCH v6 21/31] vmscan: also shrink slab in memcg pressure
@ 2013-05-12 18:13 ` Glauber Costa
0 siblings, 0 replies; 151+ messages in thread
From: Glauber Costa @ 2013-05-12 18:13 UTC (permalink / raw)
To: linux-mm
Cc: cgroups, Andrew Morton, Greg Thelen, kamezawa.hiroyu,
Michal Hocko, Johannes Weiner, linux-fsdevel, Dave Chinner,
Glauber Costa, Dave Chinner, Mel Gorman, Rik van Riel,
Hugh Dickins
Without the surrounding infrastructure, this patch is a bit of a hammer:
it will basically shrink objects from all memcgs under memcg pressure.
At least, however, we will keep the scan limited to the shrinkers marked
as per-memcg.
Future patches will implement the in-shrinker logic to filter objects
based on its memcg association.
Signed-off-by: Glauber Costa <glommer@openvz.org>
Cc: Dave Chinner <dchinner@redhat.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Rik van Riel <riel@redhat.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Michal Hocko <mhocko@suse.cz>
Cc: Hugh Dickins <hughd@google.com>
Cc: Kamezawa Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
---
include/linux/memcontrol.h | 17 +++++++++++++++++
include/linux/shrinker.h | 4 ++++
mm/memcontrol.c | 16 +++++++++++++++-
mm/vmscan.c | 46 +++++++++++++++++++++++++++++++++++++++++++---
4 files changed, 79 insertions(+), 4 deletions(-)
diff --git a/include/linux/memcontrol.h b/include/linux/memcontrol.h
index 7b4d9d7..489c6d7 100644
--- a/include/linux/memcontrol.h
+++ b/include/linux/memcontrol.h
@@ -200,6 +200,9 @@ void mem_cgroup_split_huge_fixup(struct page *head);
bool mem_cgroup_bad_page_check(struct page *page);
void mem_cgroup_print_bad_page(struct page *page);
#endif
+
+unsigned long
+memcg_zone_reclaimable_pages(struct mem_cgroup *memcg, struct zone *zone);
#else /* CONFIG_MEMCG */
struct mem_cgroup;
@@ -378,6 +381,12 @@ static inline void mem_cgroup_replace_page_cache(struct page *oldpage,
struct page *newpage)
{
}
+
+static inline unsigned long
+memcg_zone_reclaimable_pages(struct mem_cgroup *memcg, struct zone *zone)
+{
+ return 0;
+}
#endif /* CONFIG_MEMCG */
#if !defined(CONFIG_MEMCG) || !defined(CONFIG_DEBUG_VM)
@@ -430,6 +439,8 @@ static inline bool memcg_kmem_enabled(void)
return static_key_false(&memcg_kmem_enabled_key);
}
+bool memcg_kmem_is_active(struct mem_cgroup *memcg);
+
/*
* In general, we'll do everything in our power to not incur in any overhead
* for non-memcg users for the kmem functions. Not even a function call, if we
@@ -563,6 +574,12 @@ memcg_kmem_get_cache(struct kmem_cache *cachep, gfp_t gfp)
return __memcg_kmem_get_cache(cachep, gfp);
}
#else
+
+static inline bool memcg_kmem_is_active(struct mem_cgroup *memcg)
+{
+ return false;
+}
+
#define for_each_memcg_cache_index(_idx) \
for (; NULL; )
diff --git a/include/linux/shrinker.h b/include/linux/shrinker.h
index 00a3e57..3b08869 100644
--- a/include/linux/shrinker.h
+++ b/include/linux/shrinker.h
@@ -20,6 +20,9 @@ struct shrink_control {
/* shrink from these nodes */
nodemask_t nodes_to_scan;
+
+ /* reclaim from this memcg only (if not NULL) */
+ struct mem_cgroup *target_mem_cgroup;
};
/*
@@ -45,6 +48,7 @@ struct shrinker {
int seeks; /* seeks to recreate an obj */
long batch; /* reclaim batch size, 0 = default */
+ bool memcg_shrinker; /* memcg-aware shrinker */
/* These are for internal use */
struct list_head list;
diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index e34da3c..980bd2d 100644
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -465,7 +465,7 @@ static inline void memcg_kmem_set_active(struct mem_cgroup *memcg)
set_bit(KMEM_ACCOUNTED_ACTIVE, &memcg->kmem_account_flags);
}
-static bool memcg_kmem_is_active(struct mem_cgroup *memcg)
+bool memcg_kmem_is_active(struct mem_cgroup *memcg)
{
return test_bit(KMEM_ACCOUNTED_ACTIVE, &memcg->kmem_account_flags);
}
@@ -1044,6 +1044,20 @@ mem_cgroup_zone_nr_lru_pages(struct mem_cgroup *memcg, int nid, int zid,
return ret;
}
+unsigned long
+memcg_zone_reclaimable_pages(struct mem_cgroup *memcg, struct zone *zone)
+{
+ int nid = zone_to_nid(zone);
+ int zid = zone_idx(zone);
+ unsigned long val;
+
+ val = mem_cgroup_zone_nr_lru_pages(memcg, nid, zid, LRU_ALL_FILE);
+ if (do_swap_account)
+ val += mem_cgroup_zone_nr_lru_pages(memcg, nid, zid,
+ LRU_ALL_ANON);
+ return val;
+}
+
static unsigned long
mem_cgroup_node_nr_lru_pages(struct mem_cgroup *memcg,
int nid, unsigned int lru_mask)
diff --git a/mm/vmscan.c b/mm/vmscan.c
index 64f66f6..eb5e67c 100644
--- a/mm/vmscan.c
+++ b/mm/vmscan.c
@@ -139,11 +139,42 @@ static bool global_reclaim(struct scan_control *sc)
{
return !sc->target_mem_cgroup;
}
+
+/*
+ * kmem reclaim should usually not be triggered when we are doing targetted
+ * reclaim. It is only valid when global reclaim is triggered, or when the
+ * underlying memcg has kmem objects.
+ */
+static bool has_kmem_reclaim(struct scan_control *sc)
+{
+ return !sc->target_mem_cgroup ||
+ memcg_kmem_is_active(sc->target_mem_cgroup);
+}
+
+static unsigned long
+zone_nr_reclaimable_pages(struct scan_control *sc, struct zone *zone)
+{
+ if (global_reclaim(sc))
+ return zone_reclaimable_pages(zone);
+ return memcg_zone_reclaimable_pages(sc->target_mem_cgroup, zone);
+}
+
#else
static bool global_reclaim(struct scan_control *sc)
{
return true;
}
+
+static bool has_kmem_reclaim(struct scan_control *sc)
+{
+ return true;
+}
+
+static unsigned long
+zone_nr_reclaimable_pages(struct scan_control *sc, struct zone *zone)
+{
+ return zone_reclaimable_pages(zone);
+}
#endif
static unsigned long get_lru_size(struct lruvec *lruvec, enum lru_list lru)
@@ -222,6 +253,14 @@ unsigned long shrink_slab(struct shrink_control *shrinkctl,
long batch_size = shrinker->batch ? shrinker->batch
: SHRINK_BATCH;
+ /*
+ * If we don't have a target mem cgroup, we scan them all.
+ * Otherwise we will limit our scan to shrinkers marked as
+ * memcg aware
+ */
+ if (shrinkctl->target_mem_cgroup && !shrinker->memcg_shrinker)
+ continue;
+
max_pass = shrinker->count_objects(shrinker, shrinkctl);
WARN_ON(max_pass < 0);
if (max_pass <= 0)
@@ -2172,9 +2211,9 @@ static unsigned long do_try_to_free_pages(struct zonelist *zonelist,
/*
* Don't shrink slabs when reclaiming memory from
- * over limit cgroups
+ * over limit cgroups, unless we know they have kmem objects
*/
- if (global_reclaim(sc)) {
+ if (has_kmem_reclaim(sc)) {
unsigned long lru_pages = 0;
nodes_clear(shrink->nodes_to_scan);
@@ -2183,7 +2222,7 @@ static unsigned long do_try_to_free_pages(struct zonelist *zonelist,
if (!cpuset_zone_allowed_hardwall(zone, GFP_KERNEL))
continue;
- lru_pages += zone_reclaimable_pages(zone);
+ lru_pages += zone_nr_reclaimable_pages(sc, zone);
node_set(zone_to_nid(zone),
shrink->nodes_to_scan);
}
@@ -2452,6 +2491,7 @@ unsigned long try_to_free_mem_cgroup_pages(struct mem_cgroup *memcg,
};
struct shrink_control shrink = {
.gfp_mask = sc.gfp_mask,
+ .target_mem_cgroup = memcg,
};
/*
--
1.8.1.4
--
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^ permalink raw reply related [flat|nested] 151+ messages in thread
* [PATCH v6 22/31] memcg,list_lru: duplicate LRUs upon kmemcg creation
2013-05-12 18:13 ` Glauber Costa
(?)
@ 2013-05-12 18:13 ` Glauber Costa
-1 siblings, 0 replies; 151+ messages in thread
From: Glauber Costa @ 2013-05-12 18:13 UTC (permalink / raw)
To: linux-mm
Cc: cgroups, Andrew Morton, Greg Thelen, kamezawa.hiroyu,
Michal Hocko, Johannes Weiner, linux-fsdevel, Dave Chinner,
Glauber Costa, Dave Chinner, Mel Gorman, Rik van Riel,
Hugh Dickins
When a new memcg is created, we need to open up room for its descriptors
in all of the list_lrus that are marked per-memcg. The process is quite
similar to the one we are using for the kmem caches: we initialize the
new structures in an array indexed by kmemcg_id, and grow the array if
needed. Key data like the size of the array will be shared between the
kmem cache code and the list_lru code (they basically describe the same
thing)
Signed-off-by: Glauber Costa <glommer@openvz.org>
Cc: Dave Chinner <dchinner@redhat.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Rik van Riel <riel@redhat.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Michal Hocko <mhocko@suse.cz>
Cc: Hugh Dickins <hughd@google.com>
Cc: Kamezawa Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
---
include/linux/list_lru.h | 48 +++++++++++++-
include/linux/memcontrol.h | 12 ++++
lib/list_lru.c | 102 +++++++++++++++++++++++++++---
mm/memcontrol.c | 151 +++++++++++++++++++++++++++++++++++++++++++--
mm/slab_common.c | 1 -
5 files changed, 297 insertions(+), 17 deletions(-)
diff --git a/include/linux/list_lru.h b/include/linux/list_lru.h
index f5e3c15..cd67f5c 100644
--- a/include/linux/list_lru.h
+++ b/include/linux/list_lru.h
@@ -24,6 +24,23 @@ struct list_lru_node {
long nr_items;
} ____cacheline_aligned_in_smp;
+/*
+ * This is supposed to be M x N matrix, where M is kmem-limited memcg, and N is
+ * the number of nodes. Both dimensions are likely to be very small, but are
+ * potentially very big. Therefore we will allocate or grow them dynamically.
+ *
+ * The size of M will increase as new memcgs appear and can be 0 if no memcgs
+ * are being used. This is done in mm/memcontrol.c in a way quite similar than
+ * the way we use for the slab cache management.
+ *
+ * The size o N can't be determined at compile time, but won't increase once we
+ * determine it. It is nr_node_ids, the firmware-provided maximum number of
+ * nodes in a system.
+ */
+struct list_lru_array {
+ struct list_lru_node node[1];
+};
+
struct list_lru {
/*
* Because we use a fixed-size array, this struct can be very big if
@@ -37,9 +54,38 @@ struct list_lru {
*/
struct list_lru_node node[MAX_NUMNODES];
nodemask_t active_nodes;
+#ifdef CONFIG_MEMCG_KMEM
+ /* All memcg-aware LRUs will be chained in the lrus list */
+ struct list_head lrus;
+ /* M x N matrix as described above */
+ struct list_lru_array **memcg_lrus;
+#endif
};
-int list_lru_init(struct list_lru *lru);
+struct mem_cgroup;
+#ifdef CONFIG_MEMCG_KMEM
+struct list_lru_array *lru_alloc_array(void);
+int memcg_update_all_lrus(unsigned long num);
+void list_lru_destroy(struct list_lru *lru);
+void list_lru_destroy_memcg(struct mem_cgroup *memcg);
+int __memcg_init_lru(struct list_lru *lru);
+#else
+static inline void list_lru_destroy(struct list_lru *lru)
+{
+}
+#endif
+
+int __list_lru_init(struct list_lru *lru, bool memcg_enabled);
+static inline int list_lru_init(struct list_lru *lru)
+{
+ return __list_lru_init(lru, false);
+}
+
+static inline int list_lru_init_memcg(struct list_lru *lru)
+{
+ return __list_lru_init(lru, true);
+}
+
int list_lru_add(struct list_lru *lru, struct list_head *item);
int list_lru_del(struct list_lru *lru, struct list_head *item);
unsigned long
diff --git a/include/linux/memcontrol.h b/include/linux/memcontrol.h
index 489c6d7..3442eb9 100644
--- a/include/linux/memcontrol.h
+++ b/include/linux/memcontrol.h
@@ -23,6 +23,7 @@
#include <linux/vm_event_item.h>
#include <linux/hardirq.h>
#include <linux/jump_label.h>
+#include <linux/list_lru.h>
struct mem_cgroup;
struct page_cgroup;
@@ -470,6 +471,12 @@ void memcg_update_array_size(int num_groups);
struct kmem_cache *
__memcg_kmem_get_cache(struct kmem_cache *cachep, gfp_t gfp);
+int memcg_new_lru(struct list_lru *lru);
+int memcg_init_lru(struct list_lru *lru);
+
+int memcg_kmem_update_lru_size(struct list_lru *lru, int num_groups,
+ bool new_lru);
+
void mem_cgroup_destroy_cache(struct kmem_cache *cachep);
void kmem_cache_destroy_memcg_children(struct kmem_cache *s);
@@ -633,6 +640,11 @@ memcg_kmem_get_cache(struct kmem_cache *cachep, gfp_t gfp)
static inline void kmem_cache_destroy_memcg_children(struct kmem_cache *s)
{
}
+
+static inline int memcg_init_lru(struct list_lru *lru)
+{
+ return 0;
+}
#endif /* CONFIG_MEMCG_KMEM */
#endif /* _LINUX_MEMCONTROL_H */
diff --git a/lib/list_lru.c b/lib/list_lru.c
index 248be3b..5740a32 100644
--- a/lib/list_lru.c
+++ b/lib/list_lru.c
@@ -2,12 +2,17 @@
* Copyright (c) 2010-2012 Red Hat, Inc. All rights reserved.
* Author: David Chinner
*
+ * Memcg Awareness
+ * Copyright (C) 2013 Parallels Inc.
+ * Author: Glauber Costa
+ *
* Generic LRU infrastructure
*/
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/mm.h>
#include <linux/list_lru.h>
+#include <linux/memcontrol.h>
int
list_lru_add(
@@ -186,18 +191,97 @@ list_lru_dispose_all(
return total;
}
-int
-list_lru_init(
- struct list_lru *lru)
+/*
+ * This protects the list of all LRU in the system. One only needs
+ * to take when registering an LRU, or when duplicating the list of lrus.
+ * Transversing an LRU can and should be done outside the lock
+ */
+static DEFINE_MUTEX(all_memcg_lrus_mutex);
+static LIST_HEAD(all_memcg_lrus);
+
+static void list_lru_init_one(struct list_lru_node *lru)
{
+ spin_lock_init(&lru->lock);
+ INIT_LIST_HEAD(&lru->list);
+ lru->nr_items = 0;
+}
+
+struct list_lru_array *lru_alloc_array(void)
+{
+ struct list_lru_array *lru_array;
int i;
- nodes_clear(lru->active_nodes);
- for (i = 0; i < MAX_NUMNODES; i++) {
- spin_lock_init(&lru->node[i].lock);
- INIT_LIST_HEAD(&lru->node[i].list);
- lru->node[i].nr_items = 0;
+ lru_array = kzalloc(nr_node_ids * sizeof(struct list_lru_node),
+ GFP_KERNEL);
+ if (!lru_array)
+ return NULL;
+
+ for (i = 0; i < nr_node_ids; i++)
+ list_lru_init_one(&lru_array->node[i]);
+
+ return lru_array;
+}
+
+#ifdef CONFIG_MEMCG_KMEM
+int __memcg_init_lru(struct list_lru *lru)
+{
+ int ret;
+
+ INIT_LIST_HEAD(&lru->lrus);
+ mutex_lock(&all_memcg_lrus_mutex);
+ list_add(&lru->lrus, &all_memcg_lrus);
+ ret = memcg_new_lru(lru);
+ mutex_unlock(&all_memcg_lrus_mutex);
+ return ret;
+}
+
+int memcg_update_all_lrus(unsigned long num)
+{
+ int ret = 0;
+ struct list_lru *lru;
+
+ mutex_lock(&all_memcg_lrus_mutex);
+ list_for_each_entry(lru, &all_memcg_lrus, lrus) {
+ ret = memcg_kmem_update_lru_size(lru, num, false);
+ if (ret)
+ goto out;
+ }
+out:
+ mutex_unlock(&all_memcg_lrus_mutex);
+ return ret;
+}
+
+void list_lru_destroy(struct list_lru *lru)
+{
+ mutex_lock(&all_memcg_lrus_mutex);
+ list_del(&lru->lrus);
+ mutex_unlock(&all_memcg_lrus_mutex);
+}
+
+void list_lru_destroy_memcg(struct mem_cgroup *memcg)
+{
+ struct list_lru *lru;
+ mutex_lock(&all_memcg_lrus_mutex);
+ list_for_each_entry(lru, &all_memcg_lrus, lrus) {
+ kfree(lru->memcg_lrus[memcg_cache_id(memcg)]);
+ lru->memcg_lrus[memcg_cache_id(memcg)] = NULL;
+ /* everybody must beaware that this memcg is no longer valid */
+ wmb();
}
+ mutex_unlock(&all_memcg_lrus_mutex);
+}
+#endif
+
+int __list_lru_init(struct list_lru *lru, bool memcg_enabled)
+{
+ int i;
+
+ nodes_clear(lru->active_nodes);
+ for (i = 0; i < MAX_NUMNODES; i++)
+ list_lru_init_one(&lru->node[i]);
+
+ if (memcg_enabled)
+ return memcg_init_lru(lru);
return 0;
}
-EXPORT_SYMBOL_GPL(list_lru_init);
+EXPORT_SYMBOL_GPL(__list_lru_init);
diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index 980bd2d..d6f4b5e 100644
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -3163,16 +3163,30 @@ int memcg_update_cache_sizes(struct mem_cgroup *memcg)
memcg_kmem_set_activated(memcg);
ret = memcg_update_all_caches(num+1);
- if (ret) {
- ida_simple_remove(&kmem_limited_groups, num);
- memcg_kmem_clear_activated(memcg);
- return ret;
- }
+ if (ret)
+ goto out;
+
+ /*
+ * We should make sure that the array size is not updated until we are
+ * done; otherwise we have no easy way to know whether or not we should
+ * grow the array.
+ */
+ ret = memcg_update_all_lrus(num + 1);
+ if (ret)
+ goto out;
memcg->kmemcg_id = num;
+
+ memcg_update_array_size(num + 1);
+
INIT_LIST_HEAD(&memcg->memcg_slab_caches);
mutex_init(&memcg->slab_caches_mutex);
+
return 0;
+out:
+ ida_simple_remove(&kmem_limited_groups, num);
+ memcg_kmem_clear_activated(memcg);
+ return ret;
}
static size_t memcg_caches_array_size(int num_groups)
@@ -3256,6 +3270,129 @@ int memcg_update_cache_size(struct kmem_cache *s, int num_groups)
return 0;
}
+/*
+ * memcg_kmem_update_lru_size - fill in kmemcg info into a list_lru
+ *
+ * @lru: the lru we are operating with
+ * @num_groups: how many kmem-limited cgroups we have
+ * @new_lru: true if this is a new_lru being created, false if this
+ * was triggered from the memcg side
+ *
+ * Returns 0 on success, and an error code otherwise.
+ *
+ * This function can be called either when a new kmem-limited memcg appears,
+ * or when a new list_lru is created. The work is roughly the same in two cases,
+ * but in the later we never have to expand the array size.
+ *
+ * This is always protected by the all_lrus_mutex from the list_lru side. But
+ * a race can still exists if a new memcg becomes kmem limited at the same time
+ * that we are registering a new memcg. Creation is protected by the
+ * memcg_mutex, so the creation of a new lru have to be protected by that as
+ * well.
+ *
+ * The lock ordering is that the memcg_mutex needs to be acquired before the
+ * lru-side mutex.
+ */
+int memcg_kmem_update_lru_size(struct list_lru *lru, int num_groups,
+ bool new_lru)
+{
+ struct list_lru_array **new_lru_array;
+ struct list_lru_array *lru_array;
+
+ lru_array = lru_alloc_array();
+ if (!lru_array)
+ return -ENOMEM;
+
+ /*
+ * When a new LRU is created, we still need to update all data for that
+ * LRU. The procedure for late LRUs and new memcgs are quite similar, we
+ * only need to make sure we get into the loop even if num_groups <
+ * memcg_limited_groups_array_size.
+ */
+ if ((num_groups > memcg_limited_groups_array_size) || new_lru) {
+ int i;
+ struct list_lru_array **old_array;
+ size_t size = memcg_caches_array_size(num_groups);
+ int num_memcgs = memcg_limited_groups_array_size;
+
+ new_lru_array = kzalloc(size * sizeof(void *), GFP_KERNEL);
+ if (!new_lru_array) {
+ kfree(lru_array);
+ return -ENOMEM;
+ }
+
+ for (i = 0; lru->memcg_lrus && (i < num_memcgs); i++) {
+ if (lru->memcg_lrus && lru->memcg_lrus[i])
+ continue;
+ new_lru_array[i] = lru->memcg_lrus[i];
+ }
+
+ old_array = lru->memcg_lrus;
+ lru->memcg_lrus = new_lru_array;
+ /*
+ * We don't need a barrier here because we are just copying
+ * information over. Anybody operating in memcg_lrus will
+ * either follow the new array or the old one and they contain
+ * exactly the same information. The new space in the end is
+ * always empty anyway.
+ */
+ if (lru->memcg_lrus)
+ kfree(old_array);
+ }
+
+ if (lru->memcg_lrus) {
+ lru->memcg_lrus[num_groups - 1] = lru_array;
+ /*
+ * Here we do need the barrier, because of the state transition
+ * implied by the assignment of the array. All users should be
+ * able to see it
+ */
+ wmb();
+ }
+ return 0;
+}
+
+/*
+ * This is called with the LRU-mutex being held.
+ */
+int memcg_new_lru(struct list_lru *lru)
+{
+ struct mem_cgroup *iter;
+
+ if (!memcg_kmem_enabled())
+ return 0;
+
+ for_each_mem_cgroup(iter) {
+ int ret;
+ int memcg_id = memcg_cache_id(iter);
+ if (memcg_id < 0)
+ continue;
+
+ ret = memcg_kmem_update_lru_size(lru, memcg_id + 1, true);
+ if (ret) {
+ mem_cgroup_iter_break(root_mem_cgroup, iter);
+ return ret;
+ }
+ }
+ return 0;
+}
+
+/*
+ * We need to call back and forth from memcg to LRU because of the lock
+ * ordering. This complicates the flow a little bit, but since the memcg mutex
+ * is held through the whole duration of memcg creation, we need to hold it
+ * before we hold the LRU-side mutex in the case of a new list creation as
+ * well.
+ */
+int memcg_init_lru(struct list_lru *lru)
+{
+ int ret;
+ mutex_lock(&memcg_create_mutex);
+ ret = __memcg_init_lru(lru);
+ mutex_unlock(&memcg_create_mutex);
+ return ret;
+}
+
int memcg_register_cache(struct mem_cgroup *memcg, struct kmem_cache *s,
struct kmem_cache *root_cache)
{
@@ -6065,8 +6202,10 @@ static void kmem_cgroup_destroy(struct mem_cgroup *memcg)
* possible that the charges went down to 0 between mark_dead and the
* res_counter read, so in that case, we don't need the put
*/
- if (memcg_kmem_test_and_clear_dead(memcg))
+ if (memcg_kmem_test_and_clear_dead(memcg)) {
+ list_lru_destroy_memcg(memcg);
mem_cgroup_put(memcg);
+ }
}
#else
static int memcg_init_kmem(struct mem_cgroup *memcg, struct cgroup_subsys *ss)
diff --git a/mm/slab_common.c b/mm/slab_common.c
index ff3218a..b729c53 100644
--- a/mm/slab_common.c
+++ b/mm/slab_common.c
@@ -102,7 +102,6 @@ int memcg_update_all_caches(int num_memcgs)
goto out;
}
- memcg_update_array_size(num_memcgs);
out:
mutex_unlock(&slab_mutex);
return ret;
--
1.8.1.4
^ permalink raw reply related [flat|nested] 151+ messages in thread* [PATCH v6 22/31] memcg,list_lru: duplicate LRUs upon kmemcg creation
@ 2013-05-12 18:13 ` Glauber Costa
0 siblings, 0 replies; 151+ messages in thread
From: Glauber Costa @ 2013-05-12 18:13 UTC (permalink / raw)
To: linux-mm
Cc: cgroups, Andrew Morton, Greg Thelen, kamezawa.hiroyu,
Michal Hocko, Johannes Weiner, linux-fsdevel, Dave Chinner,
Glauber Costa, Dave Chinner, Mel Gorman, Rik van Riel,
Hugh Dickins
When a new memcg is created, we need to open up room for its descriptors
in all of the list_lrus that are marked per-memcg. The process is quite
similar to the one we are using for the kmem caches: we initialize the
new structures in an array indexed by kmemcg_id, and grow the array if
needed. Key data like the size of the array will be shared between the
kmem cache code and the list_lru code (they basically describe the same
thing)
Signed-off-by: Glauber Costa <glommer@openvz.org>
Cc: Dave Chinner <dchinner@redhat.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Rik van Riel <riel@redhat.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Michal Hocko <mhocko@suse.cz>
Cc: Hugh Dickins <hughd@google.com>
Cc: Kamezawa Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
---
include/linux/list_lru.h | 48 +++++++++++++-
include/linux/memcontrol.h | 12 ++++
lib/list_lru.c | 102 +++++++++++++++++++++++++++---
mm/memcontrol.c | 151 +++++++++++++++++++++++++++++++++++++++++++--
mm/slab_common.c | 1 -
5 files changed, 297 insertions(+), 17 deletions(-)
diff --git a/include/linux/list_lru.h b/include/linux/list_lru.h
index f5e3c15..cd67f5c 100644
--- a/include/linux/list_lru.h
+++ b/include/linux/list_lru.h
@@ -24,6 +24,23 @@ struct list_lru_node {
long nr_items;
} ____cacheline_aligned_in_smp;
+/*
+ * This is supposed to be M x N matrix, where M is kmem-limited memcg, and N is
+ * the number of nodes. Both dimensions are likely to be very small, but are
+ * potentially very big. Therefore we will allocate or grow them dynamically.
+ *
+ * The size of M will increase as new memcgs appear and can be 0 if no memcgs
+ * are being used. This is done in mm/memcontrol.c in a way quite similar than
+ * the way we use for the slab cache management.
+ *
+ * The size o N can't be determined at compile time, but won't increase once we
+ * determine it. It is nr_node_ids, the firmware-provided maximum number of
+ * nodes in a system.
+ */
+struct list_lru_array {
+ struct list_lru_node node[1];
+};
+
struct list_lru {
/*
* Because we use a fixed-size array, this struct can be very big if
@@ -37,9 +54,38 @@ struct list_lru {
*/
struct list_lru_node node[MAX_NUMNODES];
nodemask_t active_nodes;
+#ifdef CONFIG_MEMCG_KMEM
+ /* All memcg-aware LRUs will be chained in the lrus list */
+ struct list_head lrus;
+ /* M x N matrix as described above */
+ struct list_lru_array **memcg_lrus;
+#endif
};
-int list_lru_init(struct list_lru *lru);
+struct mem_cgroup;
+#ifdef CONFIG_MEMCG_KMEM
+struct list_lru_array *lru_alloc_array(void);
+int memcg_update_all_lrus(unsigned long num);
+void list_lru_destroy(struct list_lru *lru);
+void list_lru_destroy_memcg(struct mem_cgroup *memcg);
+int __memcg_init_lru(struct list_lru *lru);
+#else
+static inline void list_lru_destroy(struct list_lru *lru)
+{
+}
+#endif
+
+int __list_lru_init(struct list_lru *lru, bool memcg_enabled);
+static inline int list_lru_init(struct list_lru *lru)
+{
+ return __list_lru_init(lru, false);
+}
+
+static inline int list_lru_init_memcg(struct list_lru *lru)
+{
+ return __list_lru_init(lru, true);
+}
+
int list_lru_add(struct list_lru *lru, struct list_head *item);
int list_lru_del(struct list_lru *lru, struct list_head *item);
unsigned long
diff --git a/include/linux/memcontrol.h b/include/linux/memcontrol.h
index 489c6d7..3442eb9 100644
--- a/include/linux/memcontrol.h
+++ b/include/linux/memcontrol.h
@@ -23,6 +23,7 @@
#include <linux/vm_event_item.h>
#include <linux/hardirq.h>
#include <linux/jump_label.h>
+#include <linux/list_lru.h>
struct mem_cgroup;
struct page_cgroup;
@@ -470,6 +471,12 @@ void memcg_update_array_size(int num_groups);
struct kmem_cache *
__memcg_kmem_get_cache(struct kmem_cache *cachep, gfp_t gfp);
+int memcg_new_lru(struct list_lru *lru);
+int memcg_init_lru(struct list_lru *lru);
+
+int memcg_kmem_update_lru_size(struct list_lru *lru, int num_groups,
+ bool new_lru);
+
void mem_cgroup_destroy_cache(struct kmem_cache *cachep);
void kmem_cache_destroy_memcg_children(struct kmem_cache *s);
@@ -633,6 +640,11 @@ memcg_kmem_get_cache(struct kmem_cache *cachep, gfp_t gfp)
static inline void kmem_cache_destroy_memcg_children(struct kmem_cache *s)
{
}
+
+static inline int memcg_init_lru(struct list_lru *lru)
+{
+ return 0;
+}
#endif /* CONFIG_MEMCG_KMEM */
#endif /* _LINUX_MEMCONTROL_H */
diff --git a/lib/list_lru.c b/lib/list_lru.c
index 248be3b..5740a32 100644
--- a/lib/list_lru.c
+++ b/lib/list_lru.c
@@ -2,12 +2,17 @@
* Copyright (c) 2010-2012 Red Hat, Inc. All rights reserved.
* Author: David Chinner
*
+ * Memcg Awareness
+ * Copyright (C) 2013 Parallels Inc.
+ * Author: Glauber Costa
+ *
* Generic LRU infrastructure
*/
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/mm.h>
#include <linux/list_lru.h>
+#include <linux/memcontrol.h>
int
list_lru_add(
@@ -186,18 +191,97 @@ list_lru_dispose_all(
return total;
}
-int
-list_lru_init(
- struct list_lru *lru)
+/*
+ * This protects the list of all LRU in the system. One only needs
+ * to take when registering an LRU, or when duplicating the list of lrus.
+ * Transversing an LRU can and should be done outside the lock
+ */
+static DEFINE_MUTEX(all_memcg_lrus_mutex);
+static LIST_HEAD(all_memcg_lrus);
+
+static void list_lru_init_one(struct list_lru_node *lru)
{
+ spin_lock_init(&lru->lock);
+ INIT_LIST_HEAD(&lru->list);
+ lru->nr_items = 0;
+}
+
+struct list_lru_array *lru_alloc_array(void)
+{
+ struct list_lru_array *lru_array;
int i;
- nodes_clear(lru->active_nodes);
- for (i = 0; i < MAX_NUMNODES; i++) {
- spin_lock_init(&lru->node[i].lock);
- INIT_LIST_HEAD(&lru->node[i].list);
- lru->node[i].nr_items = 0;
+ lru_array = kzalloc(nr_node_ids * sizeof(struct list_lru_node),
+ GFP_KERNEL);
+ if (!lru_array)
+ return NULL;
+
+ for (i = 0; i < nr_node_ids; i++)
+ list_lru_init_one(&lru_array->node[i]);
+
+ return lru_array;
+}
+
+#ifdef CONFIG_MEMCG_KMEM
+int __memcg_init_lru(struct list_lru *lru)
+{
+ int ret;
+
+ INIT_LIST_HEAD(&lru->lrus);
+ mutex_lock(&all_memcg_lrus_mutex);
+ list_add(&lru->lrus, &all_memcg_lrus);
+ ret = memcg_new_lru(lru);
+ mutex_unlock(&all_memcg_lrus_mutex);
+ return ret;
+}
+
+int memcg_update_all_lrus(unsigned long num)
+{
+ int ret = 0;
+ struct list_lru *lru;
+
+ mutex_lock(&all_memcg_lrus_mutex);
+ list_for_each_entry(lru, &all_memcg_lrus, lrus) {
+ ret = memcg_kmem_update_lru_size(lru, num, false);
+ if (ret)
+ goto out;
+ }
+out:
+ mutex_unlock(&all_memcg_lrus_mutex);
+ return ret;
+}
+
+void list_lru_destroy(struct list_lru *lru)
+{
+ mutex_lock(&all_memcg_lrus_mutex);
+ list_del(&lru->lrus);
+ mutex_unlock(&all_memcg_lrus_mutex);
+}
+
+void list_lru_destroy_memcg(struct mem_cgroup *memcg)
+{
+ struct list_lru *lru;
+ mutex_lock(&all_memcg_lrus_mutex);
+ list_for_each_entry(lru, &all_memcg_lrus, lrus) {
+ kfree(lru->memcg_lrus[memcg_cache_id(memcg)]);
+ lru->memcg_lrus[memcg_cache_id(memcg)] = NULL;
+ /* everybody must beaware that this memcg is no longer valid */
+ wmb();
}
+ mutex_unlock(&all_memcg_lrus_mutex);
+}
+#endif
+
+int __list_lru_init(struct list_lru *lru, bool memcg_enabled)
+{
+ int i;
+
+ nodes_clear(lru->active_nodes);
+ for (i = 0; i < MAX_NUMNODES; i++)
+ list_lru_init_one(&lru->node[i]);
+
+ if (memcg_enabled)
+ return memcg_init_lru(lru);
return 0;
}
-EXPORT_SYMBOL_GPL(list_lru_init);
+EXPORT_SYMBOL_GPL(__list_lru_init);
diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index 980bd2d..d6f4b5e 100644
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -3163,16 +3163,30 @@ int memcg_update_cache_sizes(struct mem_cgroup *memcg)
memcg_kmem_set_activated(memcg);
ret = memcg_update_all_caches(num+1);
- if (ret) {
- ida_simple_remove(&kmem_limited_groups, num);
- memcg_kmem_clear_activated(memcg);
- return ret;
- }
+ if (ret)
+ goto out;
+
+ /*
+ * We should make sure that the array size is not updated until we are
+ * done; otherwise we have no easy way to know whether or not we should
+ * grow the array.
+ */
+ ret = memcg_update_all_lrus(num + 1);
+ if (ret)
+ goto out;
memcg->kmemcg_id = num;
+
+ memcg_update_array_size(num + 1);
+
INIT_LIST_HEAD(&memcg->memcg_slab_caches);
mutex_init(&memcg->slab_caches_mutex);
+
return 0;
+out:
+ ida_simple_remove(&kmem_limited_groups, num);
+ memcg_kmem_clear_activated(memcg);
+ return ret;
}
static size_t memcg_caches_array_size(int num_groups)
@@ -3256,6 +3270,129 @@ int memcg_update_cache_size(struct kmem_cache *s, int num_groups)
return 0;
}
+/*
+ * memcg_kmem_update_lru_size - fill in kmemcg info into a list_lru
+ *
+ * @lru: the lru we are operating with
+ * @num_groups: how many kmem-limited cgroups we have
+ * @new_lru: true if this is a new_lru being created, false if this
+ * was triggered from the memcg side
+ *
+ * Returns 0 on success, and an error code otherwise.
+ *
+ * This function can be called either when a new kmem-limited memcg appears,
+ * or when a new list_lru is created. The work is roughly the same in two cases,
+ * but in the later we never have to expand the array size.
+ *
+ * This is always protected by the all_lrus_mutex from the list_lru side. But
+ * a race can still exists if a new memcg becomes kmem limited at the same time
+ * that we are registering a new memcg. Creation is protected by the
+ * memcg_mutex, so the creation of a new lru have to be protected by that as
+ * well.
+ *
+ * The lock ordering is that the memcg_mutex needs to be acquired before the
+ * lru-side mutex.
+ */
+int memcg_kmem_update_lru_size(struct list_lru *lru, int num_groups,
+ bool new_lru)
+{
+ struct list_lru_array **new_lru_array;
+ struct list_lru_array *lru_array;
+
+ lru_array = lru_alloc_array();
+ if (!lru_array)
+ return -ENOMEM;
+
+ /*
+ * When a new LRU is created, we still need to update all data for that
+ * LRU. The procedure for late LRUs and new memcgs are quite similar, we
+ * only need to make sure we get into the loop even if num_groups <
+ * memcg_limited_groups_array_size.
+ */
+ if ((num_groups > memcg_limited_groups_array_size) || new_lru) {
+ int i;
+ struct list_lru_array **old_array;
+ size_t size = memcg_caches_array_size(num_groups);
+ int num_memcgs = memcg_limited_groups_array_size;
+
+ new_lru_array = kzalloc(size * sizeof(void *), GFP_KERNEL);
+ if (!new_lru_array) {
+ kfree(lru_array);
+ return -ENOMEM;
+ }
+
+ for (i = 0; lru->memcg_lrus && (i < num_memcgs); i++) {
+ if (lru->memcg_lrus && lru->memcg_lrus[i])
+ continue;
+ new_lru_array[i] = lru->memcg_lrus[i];
+ }
+
+ old_array = lru->memcg_lrus;
+ lru->memcg_lrus = new_lru_array;
+ /*
+ * We don't need a barrier here because we are just copying
+ * information over. Anybody operating in memcg_lrus will
+ * either follow the new array or the old one and they contain
+ * exactly the same information. The new space in the end is
+ * always empty anyway.
+ */
+ if (lru->memcg_lrus)
+ kfree(old_array);
+ }
+
+ if (lru->memcg_lrus) {
+ lru->memcg_lrus[num_groups - 1] = lru_array;
+ /*
+ * Here we do need the barrier, because of the state transition
+ * implied by the assignment of the array. All users should be
+ * able to see it
+ */
+ wmb();
+ }
+ return 0;
+}
+
+/*
+ * This is called with the LRU-mutex being held.
+ */
+int memcg_new_lru(struct list_lru *lru)
+{
+ struct mem_cgroup *iter;
+
+ if (!memcg_kmem_enabled())
+ return 0;
+
+ for_each_mem_cgroup(iter) {
+ int ret;
+ int memcg_id = memcg_cache_id(iter);
+ if (memcg_id < 0)
+ continue;
+
+ ret = memcg_kmem_update_lru_size(lru, memcg_id + 1, true);
+ if (ret) {
+ mem_cgroup_iter_break(root_mem_cgroup, iter);
+ return ret;
+ }
+ }
+ return 0;
+}
+
+/*
+ * We need to call back and forth from memcg to LRU because of the lock
+ * ordering. This complicates the flow a little bit, but since the memcg mutex
+ * is held through the whole duration of memcg creation, we need to hold it
+ * before we hold the LRU-side mutex in the case of a new list creation as
+ * well.
+ */
+int memcg_init_lru(struct list_lru *lru)
+{
+ int ret;
+ mutex_lock(&memcg_create_mutex);
+ ret = __memcg_init_lru(lru);
+ mutex_unlock(&memcg_create_mutex);
+ return ret;
+}
+
int memcg_register_cache(struct mem_cgroup *memcg, struct kmem_cache *s,
struct kmem_cache *root_cache)
{
@@ -6065,8 +6202,10 @@ static void kmem_cgroup_destroy(struct mem_cgroup *memcg)
* possible that the charges went down to 0 between mark_dead and the
* res_counter read, so in that case, we don't need the put
*/
- if (memcg_kmem_test_and_clear_dead(memcg))
+ if (memcg_kmem_test_and_clear_dead(memcg)) {
+ list_lru_destroy_memcg(memcg);
mem_cgroup_put(memcg);
+ }
}
#else
static int memcg_init_kmem(struct mem_cgroup *memcg, struct cgroup_subsys *ss)
diff --git a/mm/slab_common.c b/mm/slab_common.c
index ff3218a..b729c53 100644
--- a/mm/slab_common.c
+++ b/mm/slab_common.c
@@ -102,7 +102,6 @@ int memcg_update_all_caches(int num_memcgs)
goto out;
}
- memcg_update_array_size(num_memcgs);
out:
mutex_unlock(&slab_mutex);
return ret;
--
1.8.1.4
^ permalink raw reply related [flat|nested] 151+ messages in thread* [PATCH v6 22/31] memcg,list_lru: duplicate LRUs upon kmemcg creation
@ 2013-05-12 18:13 ` Glauber Costa
0 siblings, 0 replies; 151+ messages in thread
From: Glauber Costa @ 2013-05-12 18:13 UTC (permalink / raw)
To: linux-mm
Cc: cgroups, Andrew Morton, Greg Thelen, kamezawa.hiroyu,
Michal Hocko, Johannes Weiner, linux-fsdevel, Dave Chinner,
Glauber Costa, Dave Chinner, Mel Gorman, Rik van Riel,
Hugh Dickins
When a new memcg is created, we need to open up room for its descriptors
in all of the list_lrus that are marked per-memcg. The process is quite
similar to the one we are using for the kmem caches: we initialize the
new structures in an array indexed by kmemcg_id, and grow the array if
needed. Key data like the size of the array will be shared between the
kmem cache code and the list_lru code (they basically describe the same
thing)
Signed-off-by: Glauber Costa <glommer@openvz.org>
Cc: Dave Chinner <dchinner@redhat.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Rik van Riel <riel@redhat.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Michal Hocko <mhocko@suse.cz>
Cc: Hugh Dickins <hughd@google.com>
Cc: Kamezawa Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
---
include/linux/list_lru.h | 48 +++++++++++++-
include/linux/memcontrol.h | 12 ++++
lib/list_lru.c | 102 +++++++++++++++++++++++++++---
mm/memcontrol.c | 151 +++++++++++++++++++++++++++++++++++++++++++--
mm/slab_common.c | 1 -
5 files changed, 297 insertions(+), 17 deletions(-)
diff --git a/include/linux/list_lru.h b/include/linux/list_lru.h
index f5e3c15..cd67f5c 100644
--- a/include/linux/list_lru.h
+++ b/include/linux/list_lru.h
@@ -24,6 +24,23 @@ struct list_lru_node {
long nr_items;
} ____cacheline_aligned_in_smp;
+/*
+ * This is supposed to be M x N matrix, where M is kmem-limited memcg, and N is
+ * the number of nodes. Both dimensions are likely to be very small, but are
+ * potentially very big. Therefore we will allocate or grow them dynamically.
+ *
+ * The size of M will increase as new memcgs appear and can be 0 if no memcgs
+ * are being used. This is done in mm/memcontrol.c in a way quite similar than
+ * the way we use for the slab cache management.
+ *
+ * The size o N can't be determined at compile time, but won't increase once we
+ * determine it. It is nr_node_ids, the firmware-provided maximum number of
+ * nodes in a system.
+ */
+struct list_lru_array {
+ struct list_lru_node node[1];
+};
+
struct list_lru {
/*
* Because we use a fixed-size array, this struct can be very big if
@@ -37,9 +54,38 @@ struct list_lru {
*/
struct list_lru_node node[MAX_NUMNODES];
nodemask_t active_nodes;
+#ifdef CONFIG_MEMCG_KMEM
+ /* All memcg-aware LRUs will be chained in the lrus list */
+ struct list_head lrus;
+ /* M x N matrix as described above */
+ struct list_lru_array **memcg_lrus;
+#endif
};
-int list_lru_init(struct list_lru *lru);
+struct mem_cgroup;
+#ifdef CONFIG_MEMCG_KMEM
+struct list_lru_array *lru_alloc_array(void);
+int memcg_update_all_lrus(unsigned long num);
+void list_lru_destroy(struct list_lru *lru);
+void list_lru_destroy_memcg(struct mem_cgroup *memcg);
+int __memcg_init_lru(struct list_lru *lru);
+#else
+static inline void list_lru_destroy(struct list_lru *lru)
+{
+}
+#endif
+
+int __list_lru_init(struct list_lru *lru, bool memcg_enabled);
+static inline int list_lru_init(struct list_lru *lru)
+{
+ return __list_lru_init(lru, false);
+}
+
+static inline int list_lru_init_memcg(struct list_lru *lru)
+{
+ return __list_lru_init(lru, true);
+}
+
int list_lru_add(struct list_lru *lru, struct list_head *item);
int list_lru_del(struct list_lru *lru, struct list_head *item);
unsigned long
diff --git a/include/linux/memcontrol.h b/include/linux/memcontrol.h
index 489c6d7..3442eb9 100644
--- a/include/linux/memcontrol.h
+++ b/include/linux/memcontrol.h
@@ -23,6 +23,7 @@
#include <linux/vm_event_item.h>
#include <linux/hardirq.h>
#include <linux/jump_label.h>
+#include <linux/list_lru.h>
struct mem_cgroup;
struct page_cgroup;
@@ -470,6 +471,12 @@ void memcg_update_array_size(int num_groups);
struct kmem_cache *
__memcg_kmem_get_cache(struct kmem_cache *cachep, gfp_t gfp);
+int memcg_new_lru(struct list_lru *lru);
+int memcg_init_lru(struct list_lru *lru);
+
+int memcg_kmem_update_lru_size(struct list_lru *lru, int num_groups,
+ bool new_lru);
+
void mem_cgroup_destroy_cache(struct kmem_cache *cachep);
void kmem_cache_destroy_memcg_children(struct kmem_cache *s);
@@ -633,6 +640,11 @@ memcg_kmem_get_cache(struct kmem_cache *cachep, gfp_t gfp)
static inline void kmem_cache_destroy_memcg_children(struct kmem_cache *s)
{
}
+
+static inline int memcg_init_lru(struct list_lru *lru)
+{
+ return 0;
+}
#endif /* CONFIG_MEMCG_KMEM */
#endif /* _LINUX_MEMCONTROL_H */
diff --git a/lib/list_lru.c b/lib/list_lru.c
index 248be3b..5740a32 100644
--- a/lib/list_lru.c
+++ b/lib/list_lru.c
@@ -2,12 +2,17 @@
* Copyright (c) 2010-2012 Red Hat, Inc. All rights reserved.
* Author: David Chinner
*
+ * Memcg Awareness
+ * Copyright (C) 2013 Parallels Inc.
+ * Author: Glauber Costa
+ *
* Generic LRU infrastructure
*/
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/mm.h>
#include <linux/list_lru.h>
+#include <linux/memcontrol.h>
int
list_lru_add(
@@ -186,18 +191,97 @@ list_lru_dispose_all(
return total;
}
-int
-list_lru_init(
- struct list_lru *lru)
+/*
+ * This protects the list of all LRU in the system. One only needs
+ * to take when registering an LRU, or when duplicating the list of lrus.
+ * Transversing an LRU can and should be done outside the lock
+ */
+static DEFINE_MUTEX(all_memcg_lrus_mutex);
+static LIST_HEAD(all_memcg_lrus);
+
+static void list_lru_init_one(struct list_lru_node *lru)
{
+ spin_lock_init(&lru->lock);
+ INIT_LIST_HEAD(&lru->list);
+ lru->nr_items = 0;
+}
+
+struct list_lru_array *lru_alloc_array(void)
+{
+ struct list_lru_array *lru_array;
int i;
- nodes_clear(lru->active_nodes);
- for (i = 0; i < MAX_NUMNODES; i++) {
- spin_lock_init(&lru->node[i].lock);
- INIT_LIST_HEAD(&lru->node[i].list);
- lru->node[i].nr_items = 0;
+ lru_array = kzalloc(nr_node_ids * sizeof(struct list_lru_node),
+ GFP_KERNEL);
+ if (!lru_array)
+ return NULL;
+
+ for (i = 0; i < nr_node_ids; i++)
+ list_lru_init_one(&lru_array->node[i]);
+
+ return lru_array;
+}
+
+#ifdef CONFIG_MEMCG_KMEM
+int __memcg_init_lru(struct list_lru *lru)
+{
+ int ret;
+
+ INIT_LIST_HEAD(&lru->lrus);
+ mutex_lock(&all_memcg_lrus_mutex);
+ list_add(&lru->lrus, &all_memcg_lrus);
+ ret = memcg_new_lru(lru);
+ mutex_unlock(&all_memcg_lrus_mutex);
+ return ret;
+}
+
+int memcg_update_all_lrus(unsigned long num)
+{
+ int ret = 0;
+ struct list_lru *lru;
+
+ mutex_lock(&all_memcg_lrus_mutex);
+ list_for_each_entry(lru, &all_memcg_lrus, lrus) {
+ ret = memcg_kmem_update_lru_size(lru, num, false);
+ if (ret)
+ goto out;
+ }
+out:
+ mutex_unlock(&all_memcg_lrus_mutex);
+ return ret;
+}
+
+void list_lru_destroy(struct list_lru *lru)
+{
+ mutex_lock(&all_memcg_lrus_mutex);
+ list_del(&lru->lrus);
+ mutex_unlock(&all_memcg_lrus_mutex);
+}
+
+void list_lru_destroy_memcg(struct mem_cgroup *memcg)
+{
+ struct list_lru *lru;
+ mutex_lock(&all_memcg_lrus_mutex);
+ list_for_each_entry(lru, &all_memcg_lrus, lrus) {
+ kfree(lru->memcg_lrus[memcg_cache_id(memcg)]);
+ lru->memcg_lrus[memcg_cache_id(memcg)] = NULL;
+ /* everybody must beaware that this memcg is no longer valid */
+ wmb();
}
+ mutex_unlock(&all_memcg_lrus_mutex);
+}
+#endif
+
+int __list_lru_init(struct list_lru *lru, bool memcg_enabled)
+{
+ int i;
+
+ nodes_clear(lru->active_nodes);
+ for (i = 0; i < MAX_NUMNODES; i++)
+ list_lru_init_one(&lru->node[i]);
+
+ if (memcg_enabled)
+ return memcg_init_lru(lru);
return 0;
}
-EXPORT_SYMBOL_GPL(list_lru_init);
+EXPORT_SYMBOL_GPL(__list_lru_init);
diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index 980bd2d..d6f4b5e 100644
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -3163,16 +3163,30 @@ int memcg_update_cache_sizes(struct mem_cgroup *memcg)
memcg_kmem_set_activated(memcg);
ret = memcg_update_all_caches(num+1);
- if (ret) {
- ida_simple_remove(&kmem_limited_groups, num);
- memcg_kmem_clear_activated(memcg);
- return ret;
- }
+ if (ret)
+ goto out;
+
+ /*
+ * We should make sure that the array size is not updated until we are
+ * done; otherwise we have no easy way to know whether or not we should
+ * grow the array.
+ */
+ ret = memcg_update_all_lrus(num + 1);
+ if (ret)
+ goto out;
memcg->kmemcg_id = num;
+
+ memcg_update_array_size(num + 1);
+
INIT_LIST_HEAD(&memcg->memcg_slab_caches);
mutex_init(&memcg->slab_caches_mutex);
+
return 0;
+out:
+ ida_simple_remove(&kmem_limited_groups, num);
+ memcg_kmem_clear_activated(memcg);
+ return ret;
}
static size_t memcg_caches_array_size(int num_groups)
@@ -3256,6 +3270,129 @@ int memcg_update_cache_size(struct kmem_cache *s, int num_groups)
return 0;
}
+/*
+ * memcg_kmem_update_lru_size - fill in kmemcg info into a list_lru
+ *
+ * @lru: the lru we are operating with
+ * @num_groups: how many kmem-limited cgroups we have
+ * @new_lru: true if this is a new_lru being created, false if this
+ * was triggered from the memcg side
+ *
+ * Returns 0 on success, and an error code otherwise.
+ *
+ * This function can be called either when a new kmem-limited memcg appears,
+ * or when a new list_lru is created. The work is roughly the same in two cases,
+ * but in the later we never have to expand the array size.
+ *
+ * This is always protected by the all_lrus_mutex from the list_lru side. But
+ * a race can still exists if a new memcg becomes kmem limited at the same time
+ * that we are registering a new memcg. Creation is protected by the
+ * memcg_mutex, so the creation of a new lru have to be protected by that as
+ * well.
+ *
+ * The lock ordering is that the memcg_mutex needs to be acquired before the
+ * lru-side mutex.
+ */
+int memcg_kmem_update_lru_size(struct list_lru *lru, int num_groups,
+ bool new_lru)
+{
+ struct list_lru_array **new_lru_array;
+ struct list_lru_array *lru_array;
+
+ lru_array = lru_alloc_array();
+ if (!lru_array)
+ return -ENOMEM;
+
+ /*
+ * When a new LRU is created, we still need to update all data for that
+ * LRU. The procedure for late LRUs and new memcgs are quite similar, we
+ * only need to make sure we get into the loop even if num_groups <
+ * memcg_limited_groups_array_size.
+ */
+ if ((num_groups > memcg_limited_groups_array_size) || new_lru) {
+ int i;
+ struct list_lru_array **old_array;
+ size_t size = memcg_caches_array_size(num_groups);
+ int num_memcgs = memcg_limited_groups_array_size;
+
+ new_lru_array = kzalloc(size * sizeof(void *), GFP_KERNEL);
+ if (!new_lru_array) {
+ kfree(lru_array);
+ return -ENOMEM;
+ }
+
+ for (i = 0; lru->memcg_lrus && (i < num_memcgs); i++) {
+ if (lru->memcg_lrus && lru->memcg_lrus[i])
+ continue;
+ new_lru_array[i] = lru->memcg_lrus[i];
+ }
+
+ old_array = lru->memcg_lrus;
+ lru->memcg_lrus = new_lru_array;
+ /*
+ * We don't need a barrier here because we are just copying
+ * information over. Anybody operating in memcg_lrus will
+ * either follow the new array or the old one and they contain
+ * exactly the same information. The new space in the end is
+ * always empty anyway.
+ */
+ if (lru->memcg_lrus)
+ kfree(old_array);
+ }
+
+ if (lru->memcg_lrus) {
+ lru->memcg_lrus[num_groups - 1] = lru_array;
+ /*
+ * Here we do need the barrier, because of the state transition
+ * implied by the assignment of the array. All users should be
+ * able to see it
+ */
+ wmb();
+ }
+ return 0;
+}
+
+/*
+ * This is called with the LRU-mutex being held.
+ */
+int memcg_new_lru(struct list_lru *lru)
+{
+ struct mem_cgroup *iter;
+
+ if (!memcg_kmem_enabled())
+ return 0;
+
+ for_each_mem_cgroup(iter) {
+ int ret;
+ int memcg_id = memcg_cache_id(iter);
+ if (memcg_id < 0)
+ continue;
+
+ ret = memcg_kmem_update_lru_size(lru, memcg_id + 1, true);
+ if (ret) {
+ mem_cgroup_iter_break(root_mem_cgroup, iter);
+ return ret;
+ }
+ }
+ return 0;
+}
+
+/*
+ * We need to call back and forth from memcg to LRU because of the lock
+ * ordering. This complicates the flow a little bit, but since the memcg mutex
+ * is held through the whole duration of memcg creation, we need to hold it
+ * before we hold the LRU-side mutex in the case of a new list creation as
+ * well.
+ */
+int memcg_init_lru(struct list_lru *lru)
+{
+ int ret;
+ mutex_lock(&memcg_create_mutex);
+ ret = __memcg_init_lru(lru);
+ mutex_unlock(&memcg_create_mutex);
+ return ret;
+}
+
int memcg_register_cache(struct mem_cgroup *memcg, struct kmem_cache *s,
struct kmem_cache *root_cache)
{
@@ -6065,8 +6202,10 @@ static void kmem_cgroup_destroy(struct mem_cgroup *memcg)
* possible that the charges went down to 0 between mark_dead and the
* res_counter read, so in that case, we don't need the put
*/
- if (memcg_kmem_test_and_clear_dead(memcg))
+ if (memcg_kmem_test_and_clear_dead(memcg)) {
+ list_lru_destroy_memcg(memcg);
mem_cgroup_put(memcg);
+ }
}
#else
static int memcg_init_kmem(struct mem_cgroup *memcg, struct cgroup_subsys *ss)
diff --git a/mm/slab_common.c b/mm/slab_common.c
index ff3218a..b729c53 100644
--- a/mm/slab_common.c
+++ b/mm/slab_common.c
@@ -102,7 +102,6 @@ int memcg_update_all_caches(int num_memcgs)
goto out;
}
- memcg_update_array_size(num_memcgs);
out:
mutex_unlock(&slab_mutex);
return ret;
--
1.8.1.4
--
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^ permalink raw reply related [flat|nested] 151+ messages in thread
* [PATCH v6 23/31] lru: add an element to a memcg list
2013-05-12 18:13 ` Glauber Costa
@ 2013-05-12 18:13 ` Glauber Costa
-1 siblings, 0 replies; 151+ messages in thread
From: Glauber Costa @ 2013-05-12 18:13 UTC (permalink / raw)
To: linux-mm
Cc: cgroups, Andrew Morton, Greg Thelen, kamezawa.hiroyu,
Michal Hocko, Johannes Weiner, linux-fsdevel, Dave Chinner,
Glauber Costa, Dave Chinner, Mel Gorman, Rik van Riel,
Hugh Dickins
With the infrastructure we now have, we can add an element to a memcg
LRU list instead of the global list. The memcg lists are still
per-node.
Technically, we will never trigger per-node shrinking in the memcg is
short of memory. Therefore an alternative to this would be to add the
element to *both* a single-node memcg array and a per-node global array.
There are two main reasons for this design choice:
1) adding an extra list_head to each of the objects would waste 16-bytes
per object, always remembering that we are talking about 1 dentry + 1
inode in the common case. This means a close to 10 % increase in the
dentry size, and a lower yet significant increase in the inode size. In
terms of total memory, this design pays 32-byte per-superblock-per-node
(size of struct list_lru_node), which means that in any scenario where
we have more than 10 dentries + inodes, we would already be paying more
memory in the two-list-heads approach than we will here with 1 node x 10
superblocks. The turning point of course depends on the workload, but I
hope the figures above would convince you that the memory footprint is
in my side in any workload that matters.
2) The main drawback of this, namely, that we loose global LRU order, is
not really seen by me as a disadvantage: if we are using memcg to
isolate the workloads, global pressure should try to balance the amount
reclaimed from all memcgs the same way the shrinkers will already
naturally balance the amount reclaimed from each superblock. (This
patchset needs some love in this regard, btw).
To help us easily tracking down which nodes have and which nodes doesn't
have elements in the list, we will count on an auxiliary node bitmap in
the global level.
[ v2: move memcg_kmem_lru_of_page to list_lru.c and then unpublish the
auxiliary functions it uses ]
Signed-off-by: Glauber Costa <glommer@openvz.org>
Cc: Dave Chinner <dchinner@redhat.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Rik van Riel <riel@redhat.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Michal Hocko <mhocko@suse.cz>
Cc: Hugh Dickins <hughd@google.com>
Cc: Kamezawa Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
---
include/linux/list_lru.h | 11 +++++
include/linux/memcontrol.h | 8 ++++
lib/list_lru.c | 104 +++++++++++++++++++++++++++++++++++++++++----
mm/memcontrol.c | 24 ++++++++++-
4 files changed, 137 insertions(+), 10 deletions(-)
diff --git a/include/linux/list_lru.h b/include/linux/list_lru.h
index cd67f5c..f6756fb 100644
--- a/include/linux/list_lru.h
+++ b/include/linux/list_lru.h
@@ -53,12 +53,23 @@ struct list_lru {
* structure, we may very well fail.
*/
struct list_lru_node node[MAX_NUMNODES];
+ atomic_long_t node_totals[MAX_NUMNODES];
nodemask_t active_nodes;
#ifdef CONFIG_MEMCG_KMEM
/* All memcg-aware LRUs will be chained in the lrus list */
struct list_head lrus;
/* M x N matrix as described above */
struct list_lru_array **memcg_lrus;
+ /*
+ * The memcg_lrus is RCU protected, so we need to keep the previous
+ * array around when we update it. But we can only do that after
+ * synchronize_rcu(). A typical system has many LRUs, which means
+ * that if we call synchronize_rcu after each LRU update, this
+ * will become very expensive. We add this pointer here, and then
+ * after all LRUs are update, we call synchronize_rcu() once, and
+ * free all the old_arrays.
+ */
+ void *old_array;
#endif
};
diff --git a/include/linux/memcontrol.h b/include/linux/memcontrol.h
index 3442eb9..50f199f 100644
--- a/include/linux/memcontrol.h
+++ b/include/linux/memcontrol.h
@@ -24,6 +24,7 @@
#include <linux/hardirq.h>
#include <linux/jump_label.h>
#include <linux/list_lru.h>
+#include <linux/mm.h>
struct mem_cgroup;
struct page_cgroup;
@@ -474,6 +475,8 @@ __memcg_kmem_get_cache(struct kmem_cache *cachep, gfp_t gfp);
int memcg_new_lru(struct list_lru *lru);
int memcg_init_lru(struct list_lru *lru);
+struct mem_cgroup *mem_cgroup_from_kmem_page(struct page *page);
+
int memcg_kmem_update_lru_size(struct list_lru *lru, int num_groups,
bool new_lru);
@@ -645,6 +648,11 @@ static inline int memcg_init_lru(struct list_lru *lru)
{
return 0;
}
+
+static inline struct mem_cgroup *mem_cgroup_from_kmem_page(struct page *page)
+{
+ return NULL;
+}
#endif /* CONFIG_MEMCG_KMEM */
#endif /* _LINUX_MEMCONTROL_H */
diff --git a/lib/list_lru.c b/lib/list_lru.c
index 5740a32..a5753b2 100644
--- a/lib/list_lru.c
+++ b/lib/list_lru.c
@@ -14,19 +14,85 @@
#include <linux/list_lru.h>
#include <linux/memcontrol.h>
+/*
+ * lru_node_of_index - returns the node-lru of a specific lru
+ * @lru: the global lru we are operating at
+ * @index: if positive, the memcg id. If negative, means global lru.
+ * @nid: node id of the corresponding node we want to manipulate
+ */
+struct list_lru_node *
+lru_node_of_index(struct list_lru *lru, int index, int nid)
+{
+#ifdef CONFIG_MEMCG_KMEM
+ struct list_lru_node *nlru;
+
+ if (index < 0)
+ return &lru->node[nid];
+
+ if (!lru->memcg_lrus)
+ return NULL;
+
+ /*
+ * because we will only ever free the memcg_lrus after synchronize_rcu,
+ * we are safe with the rcu lock here: even if we are operating in the
+ * stale version of the array, the data is still valid and we are not
+ * risking anything.
+ *
+ * The read barrier is needed to make sure that we see the pointer
+ * assigment for the specific memcg
+ */
+ rcu_read_lock();
+ rmb();
+ /* The array exist, but the particular memcg does not */
+ if (!lru->memcg_lrus[index]) {
+ nlru = NULL;
+ goto out;
+ }
+ nlru = &lru->memcg_lrus[index]->node[nid];
+out:
+ rcu_read_unlock();
+ return nlru;
+#else
+ BUG_ON(index >= 0); /* nobody should be passing index < 0 with !KMEM */
+ return &lru->node[nid];
+#endif
+}
+
+struct list_lru_node *
+memcg_kmem_lru_of_page(struct list_lru *lru, struct page *page)
+{
+ struct mem_cgroup *memcg = mem_cgroup_from_kmem_page(page);
+ int nid = page_to_nid(page);
+ int memcg_id;
+
+ if (!memcg || !memcg_kmem_is_active(memcg))
+ return &lru->node[nid];
+
+ memcg_id = memcg_cache_id(memcg);
+ return lru_node_of_index(lru, memcg_id, nid);
+}
+
int
list_lru_add(
struct list_lru *lru,
struct list_head *item)
{
- int nid = page_to_nid(virt_to_page(item));
- struct list_lru_node *nlru = &lru->node[nid];
+ struct page *page = virt_to_page(item);
+ struct list_lru_node *nlru;
+ int nid = page_to_nid(page);
+
+ nlru = memcg_kmem_lru_of_page(lru, page);
spin_lock(&nlru->lock);
BUG_ON(nlru->nr_items < 0);
if (list_empty(item)) {
list_add_tail(item, &nlru->list);
- if (nlru->nr_items++ == 0)
+ nlru->nr_items++;
+ /*
+ * We only consider a node active or inactive based on the
+ * total figure for all involved children.
+ */
+ if (atomic_long_add_return(1, &lru->node_totals[nid]) == 1)
node_set(nid, lru->active_nodes);
spin_unlock(&nlru->lock);
return 1;
@@ -41,14 +107,20 @@ list_lru_del(
struct list_lru *lru,
struct list_head *item)
{
- int nid = page_to_nid(virt_to_page(item));
- struct list_lru_node *nlru = &lru->node[nid];
+ struct page *page = virt_to_page(item);
+ struct list_lru_node *nlru;
+ int nid = page_to_nid(page);
+
+ nlru = memcg_kmem_lru_of_page(lru, page);
spin_lock(&nlru->lock);
if (!list_empty(item)) {
list_del_init(item);
- if (--nlru->nr_items == 0)
+ nlru->nr_items--;
+
+ if (atomic_long_dec_and_test(&lru->node_totals[nid]))
node_clear(nid, lru->active_nodes);
+
BUG_ON(nlru->nr_items < 0);
spin_unlock(&nlru->lock);
return 1;
@@ -97,9 +169,10 @@ restart:
ret = isolate(item, &nlru->lock, cb_arg);
switch (ret) {
case LRU_REMOVED:
- if (--nlru->nr_items == 0)
- node_clear(nid, lru->active_nodes);
+ nlru->nr_items--;
BUG_ON(nlru->nr_items < 0);
+ if (atomic_long_dec_and_test(&lru->node_totals[nid]))
+ node_clear(nid, lru->active_nodes);
isolated++;
break;
case LRU_ROTATE:
@@ -247,6 +320,17 @@ int memcg_update_all_lrus(unsigned long num)
goto out;
}
out:
+ /*
+ * Even if we were to use call_rcu, we still have to keep the old array
+ * pointer somewhere. It is easier for us to just synchronize rcu here
+ * since we are in a fine context. Now we guarantee that there are no
+ * more users of old_array, and proceed freeing it for all LRUs
+ */
+ synchronize_rcu();
+ list_for_each_entry(lru, &all_memcg_lrus, lrus) {
+ kfree(lru->old_array);
+ lru->old_array = NULL;
+ }
mutex_unlock(&all_memcg_lrus_mutex);
return ret;
}
@@ -277,8 +361,10 @@ int __list_lru_init(struct list_lru *lru, bool memcg_enabled)
int i;
nodes_clear(lru->active_nodes);
- for (i = 0; i < MAX_NUMNODES; i++)
+ for (i = 0; i < MAX_NUMNODES; i++) {
list_lru_init_one(&lru->node[i]);
+ atomic_long_set(&lru->node_totals[i], 0);
+ }
if (memcg_enabled)
return memcg_init_lru(lru);
diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index d6f4b5e..4bf6738 100644
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -3335,9 +3335,15 @@ int memcg_kmem_update_lru_size(struct list_lru *lru, int num_groups,
* either follow the new array or the old one and they contain
* exactly the same information. The new space in the end is
* always empty anyway.
+ *
+ * We do have to make sure that no more users of the old
+ * memcg_lrus array exist before we free, and this is achieved
+ * by rcu. Since it would be too slow to synchronize RCU for
+ * every LRU, we store the pointer and let the LRU code free
+ * all of them when all LRUs are updated.
*/
if (lru->memcg_lrus)
- kfree(old_array);
+ lru->old_array = old_array;
}
if (lru->memcg_lrus) {
@@ -3481,6 +3487,22 @@ static inline void memcg_resume_kmem_account(void)
current->memcg_kmem_skip_account--;
}
+struct mem_cgroup *mem_cgroup_from_kmem_page(struct page *page)
+{
+ struct page_cgroup *pc;
+ struct mem_cgroup *memcg = NULL;
+
+ pc = lookup_page_cgroup(page);
+ if (!PageCgroupUsed(pc))
+ return NULL;
+
+ lock_page_cgroup(pc);
+ if (PageCgroupUsed(pc))
+ memcg = pc->mem_cgroup;
+ unlock_page_cgroup(pc);
+ return memcg;
+}
+
static void kmem_cache_destroy_work_func(struct work_struct *w)
{
struct kmem_cache *cachep;
--
1.8.1.4
--
To unsubscribe, send a message with 'unsubscribe linux-mm' in
the body to majordomo@kvack.org. For more info on Linux MM,
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^ permalink raw reply related [flat|nested] 151+ messages in thread* [PATCH v6 23/31] lru: add an element to a memcg list
@ 2013-05-12 18:13 ` Glauber Costa
0 siblings, 0 replies; 151+ messages in thread
From: Glauber Costa @ 2013-05-12 18:13 UTC (permalink / raw)
To: linux-mm
Cc: cgroups, Andrew Morton, Greg Thelen, kamezawa.hiroyu,
Michal Hocko, Johannes Weiner, linux-fsdevel, Dave Chinner,
Glauber Costa, Dave Chinner, Mel Gorman, Rik van Riel,
Hugh Dickins
With the infrastructure we now have, we can add an element to a memcg
LRU list instead of the global list. The memcg lists are still
per-node.
Technically, we will never trigger per-node shrinking in the memcg is
short of memory. Therefore an alternative to this would be to add the
element to *both* a single-node memcg array and a per-node global array.
There are two main reasons for this design choice:
1) adding an extra list_head to each of the objects would waste 16-bytes
per object, always remembering that we are talking about 1 dentry + 1
inode in the common case. This means a close to 10 % increase in the
dentry size, and a lower yet significant increase in the inode size. In
terms of total memory, this design pays 32-byte per-superblock-per-node
(size of struct list_lru_node), which means that in any scenario where
we have more than 10 dentries + inodes, we would already be paying more
memory in the two-list-heads approach than we will here with 1 node x 10
superblocks. The turning point of course depends on the workload, but I
hope the figures above would convince you that the memory footprint is
in my side in any workload that matters.
2) The main drawback of this, namely, that we loose global LRU order, is
not really seen by me as a disadvantage: if we are using memcg to
isolate the workloads, global pressure should try to balance the amount
reclaimed from all memcgs the same way the shrinkers will already
naturally balance the amount reclaimed from each superblock. (This
patchset needs some love in this regard, btw).
To help us easily tracking down which nodes have and which nodes doesn't
have elements in the list, we will count on an auxiliary node bitmap in
the global level.
[ v2: move memcg_kmem_lru_of_page to list_lru.c and then unpublish the
auxiliary functions it uses ]
Signed-off-by: Glauber Costa <glommer@openvz.org>
Cc: Dave Chinner <dchinner@redhat.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Rik van Riel <riel@redhat.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Michal Hocko <mhocko@suse.cz>
Cc: Hugh Dickins <hughd@google.com>
Cc: Kamezawa Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
---
include/linux/list_lru.h | 11 +++++
include/linux/memcontrol.h | 8 ++++
lib/list_lru.c | 104 +++++++++++++++++++++++++++++++++++++++++----
mm/memcontrol.c | 24 ++++++++++-
4 files changed, 137 insertions(+), 10 deletions(-)
diff --git a/include/linux/list_lru.h b/include/linux/list_lru.h
index cd67f5c..f6756fb 100644
--- a/include/linux/list_lru.h
+++ b/include/linux/list_lru.h
@@ -53,12 +53,23 @@ struct list_lru {
* structure, we may very well fail.
*/
struct list_lru_node node[MAX_NUMNODES];
+ atomic_long_t node_totals[MAX_NUMNODES];
nodemask_t active_nodes;
#ifdef CONFIG_MEMCG_KMEM
/* All memcg-aware LRUs will be chained in the lrus list */
struct list_head lrus;
/* M x N matrix as described above */
struct list_lru_array **memcg_lrus;
+ /*
+ * The memcg_lrus is RCU protected, so we need to keep the previous
+ * array around when we update it. But we can only do that after
+ * synchronize_rcu(). A typical system has many LRUs, which means
+ * that if we call synchronize_rcu after each LRU update, this
+ * will become very expensive. We add this pointer here, and then
+ * after all LRUs are update, we call synchronize_rcu() once, and
+ * free all the old_arrays.
+ */
+ void *old_array;
#endif
};
diff --git a/include/linux/memcontrol.h b/include/linux/memcontrol.h
index 3442eb9..50f199f 100644
--- a/include/linux/memcontrol.h
+++ b/include/linux/memcontrol.h
@@ -24,6 +24,7 @@
#include <linux/hardirq.h>
#include <linux/jump_label.h>
#include <linux/list_lru.h>
+#include <linux/mm.h>
struct mem_cgroup;
struct page_cgroup;
@@ -474,6 +475,8 @@ __memcg_kmem_get_cache(struct kmem_cache *cachep, gfp_t gfp);
int memcg_new_lru(struct list_lru *lru);
int memcg_init_lru(struct list_lru *lru);
+struct mem_cgroup *mem_cgroup_from_kmem_page(struct page *page);
+
int memcg_kmem_update_lru_size(struct list_lru *lru, int num_groups,
bool new_lru);
@@ -645,6 +648,11 @@ static inline int memcg_init_lru(struct list_lru *lru)
{
return 0;
}
+
+static inline struct mem_cgroup *mem_cgroup_from_kmem_page(struct page *page)
+{
+ return NULL;
+}
#endif /* CONFIG_MEMCG_KMEM */
#endif /* _LINUX_MEMCONTROL_H */
diff --git a/lib/list_lru.c b/lib/list_lru.c
index 5740a32..a5753b2 100644
--- a/lib/list_lru.c
+++ b/lib/list_lru.c
@@ -14,19 +14,85 @@
#include <linux/list_lru.h>
#include <linux/memcontrol.h>
+/*
+ * lru_node_of_index - returns the node-lru of a specific lru
+ * @lru: the global lru we are operating at
+ * @index: if positive, the memcg id. If negative, means global lru.
+ * @nid: node id of the corresponding node we want to manipulate
+ */
+struct list_lru_node *
+lru_node_of_index(struct list_lru *lru, int index, int nid)
+{
+#ifdef CONFIG_MEMCG_KMEM
+ struct list_lru_node *nlru;
+
+ if (index < 0)
+ return &lru->node[nid];
+
+ if (!lru->memcg_lrus)
+ return NULL;
+
+ /*
+ * because we will only ever free the memcg_lrus after synchronize_rcu,
+ * we are safe with the rcu lock here: even if we are operating in the
+ * stale version of the array, the data is still valid and we are not
+ * risking anything.
+ *
+ * The read barrier is needed to make sure that we see the pointer
+ * assigment for the specific memcg
+ */
+ rcu_read_lock();
+ rmb();
+ /* The array exist, but the particular memcg does not */
+ if (!lru->memcg_lrus[index]) {
+ nlru = NULL;
+ goto out;
+ }
+ nlru = &lru->memcg_lrus[index]->node[nid];
+out:
+ rcu_read_unlock();
+ return nlru;
+#else
+ BUG_ON(index >= 0); /* nobody should be passing index < 0 with !KMEM */
+ return &lru->node[nid];
+#endif
+}
+
+struct list_lru_node *
+memcg_kmem_lru_of_page(struct list_lru *lru, struct page *page)
+{
+ struct mem_cgroup *memcg = mem_cgroup_from_kmem_page(page);
+ int nid = page_to_nid(page);
+ int memcg_id;
+
+ if (!memcg || !memcg_kmem_is_active(memcg))
+ return &lru->node[nid];
+
+ memcg_id = memcg_cache_id(memcg);
+ return lru_node_of_index(lru, memcg_id, nid);
+}
+
int
list_lru_add(
struct list_lru *lru,
struct list_head *item)
{
- int nid = page_to_nid(virt_to_page(item));
- struct list_lru_node *nlru = &lru->node[nid];
+ struct page *page = virt_to_page(item);
+ struct list_lru_node *nlru;
+ int nid = page_to_nid(page);
+
+ nlru = memcg_kmem_lru_of_page(lru, page);
spin_lock(&nlru->lock);
BUG_ON(nlru->nr_items < 0);
if (list_empty(item)) {
list_add_tail(item, &nlru->list);
- if (nlru->nr_items++ == 0)
+ nlru->nr_items++;
+ /*
+ * We only consider a node active or inactive based on the
+ * total figure for all involved children.
+ */
+ if (atomic_long_add_return(1, &lru->node_totals[nid]) == 1)
node_set(nid, lru->active_nodes);
spin_unlock(&nlru->lock);
return 1;
@@ -41,14 +107,20 @@ list_lru_del(
struct list_lru *lru,
struct list_head *item)
{
- int nid = page_to_nid(virt_to_page(item));
- struct list_lru_node *nlru = &lru->node[nid];
+ struct page *page = virt_to_page(item);
+ struct list_lru_node *nlru;
+ int nid = page_to_nid(page);
+
+ nlru = memcg_kmem_lru_of_page(lru, page);
spin_lock(&nlru->lock);
if (!list_empty(item)) {
list_del_init(item);
- if (--nlru->nr_items == 0)
+ nlru->nr_items--;
+
+ if (atomic_long_dec_and_test(&lru->node_totals[nid]))
node_clear(nid, lru->active_nodes);
+
BUG_ON(nlru->nr_items < 0);
spin_unlock(&nlru->lock);
return 1;
@@ -97,9 +169,10 @@ restart:
ret = isolate(item, &nlru->lock, cb_arg);
switch (ret) {
case LRU_REMOVED:
- if (--nlru->nr_items == 0)
- node_clear(nid, lru->active_nodes);
+ nlru->nr_items--;
BUG_ON(nlru->nr_items < 0);
+ if (atomic_long_dec_and_test(&lru->node_totals[nid]))
+ node_clear(nid, lru->active_nodes);
isolated++;
break;
case LRU_ROTATE:
@@ -247,6 +320,17 @@ int memcg_update_all_lrus(unsigned long num)
goto out;
}
out:
+ /*
+ * Even if we were to use call_rcu, we still have to keep the old array
+ * pointer somewhere. It is easier for us to just synchronize rcu here
+ * since we are in a fine context. Now we guarantee that there are no
+ * more users of old_array, and proceed freeing it for all LRUs
+ */
+ synchronize_rcu();
+ list_for_each_entry(lru, &all_memcg_lrus, lrus) {
+ kfree(lru->old_array);
+ lru->old_array = NULL;
+ }
mutex_unlock(&all_memcg_lrus_mutex);
return ret;
}
@@ -277,8 +361,10 @@ int __list_lru_init(struct list_lru *lru, bool memcg_enabled)
int i;
nodes_clear(lru->active_nodes);
- for (i = 0; i < MAX_NUMNODES; i++)
+ for (i = 0; i < MAX_NUMNODES; i++) {
list_lru_init_one(&lru->node[i]);
+ atomic_long_set(&lru->node_totals[i], 0);
+ }
if (memcg_enabled)
return memcg_init_lru(lru);
diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index d6f4b5e..4bf6738 100644
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -3335,9 +3335,15 @@ int memcg_kmem_update_lru_size(struct list_lru *lru, int num_groups,
* either follow the new array or the old one and they contain
* exactly the same information. The new space in the end is
* always empty anyway.
+ *
+ * We do have to make sure that no more users of the old
+ * memcg_lrus array exist before we free, and this is achieved
+ * by rcu. Since it would be too slow to synchronize RCU for
+ * every LRU, we store the pointer and let the LRU code free
+ * all of them when all LRUs are updated.
*/
if (lru->memcg_lrus)
- kfree(old_array);
+ lru->old_array = old_array;
}
if (lru->memcg_lrus) {
@@ -3481,6 +3487,22 @@ static inline void memcg_resume_kmem_account(void)
current->memcg_kmem_skip_account--;
}
+struct mem_cgroup *mem_cgroup_from_kmem_page(struct page *page)
+{
+ struct page_cgroup *pc;
+ struct mem_cgroup *memcg = NULL;
+
+ pc = lookup_page_cgroup(page);
+ if (!PageCgroupUsed(pc))
+ return NULL;
+
+ lock_page_cgroup(pc);
+ if (PageCgroupUsed(pc))
+ memcg = pc->mem_cgroup;
+ unlock_page_cgroup(pc);
+ return memcg;
+}
+
static void kmem_cache_destroy_work_func(struct work_struct *w)
{
struct kmem_cache *cachep;
--
1.8.1.4
--
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^ permalink raw reply related [flat|nested] 151+ messages in thread
* [PATCH v6 24/31] list_lru: per-memcg walks
2013-05-12 18:13 ` Glauber Costa
(?)
@ 2013-05-12 18:13 ` Glauber Costa
-1 siblings, 0 replies; 151+ messages in thread
From: Glauber Costa @ 2013-05-12 18:13 UTC (permalink / raw)
To: linux-mm
Cc: cgroups, Andrew Morton, Greg Thelen, kamezawa.hiroyu,
Michal Hocko, Johannes Weiner, linux-fsdevel, Dave Chinner,
Glauber Costa, Dave Chinner, Mel Gorman, Rik van Riel,
Hugh Dickins
This patch extend the list_lru interfaces to allow for a memcg
parameter. Because most of its users won't need it, instead of
modifying the function signatures we create a new set of _memcg()
functions and write the old API ontop of that.
Signed-off-by: Glauber Costa <glommer@openvz.org>
Cc: Dave Chinner <dchinner@redhat.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Rik van Riel <riel@redhat.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Michal Hocko <mhocko@suse.cz>
Cc: Hugh Dickins <hughd@google.com>
Cc: Kamezawa Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
---
include/linux/list_lru.h | 26 ++++++++---
include/linux/memcontrol.h | 2 +
lib/list_lru.c | 110 ++++++++++++++++++++++++++++++++++-----------
3 files changed, 107 insertions(+), 31 deletions(-)
diff --git a/include/linux/list_lru.h b/include/linux/list_lru.h
index f6756fb..9e6bbb1 100644
--- a/include/linux/list_lru.h
+++ b/include/linux/list_lru.h
@@ -99,23 +99,37 @@ static inline int list_lru_init_memcg(struct list_lru *lru)
int list_lru_add(struct list_lru *lru, struct list_head *item);
int list_lru_del(struct list_lru *lru, struct list_head *item);
-unsigned long
-list_lru_count_nodemask(struct list_lru *lru, nodemask_t *nodes_to_count);
+
+unsigned long list_lru_count_nodemask_memcg(struct list_lru *lru,
+ nodemask_t *nodes_to_count, struct mem_cgroup *memcg);
+
+static inline unsigned long
+list_lru_count_nodemask(struct list_lru *lru, nodemask_t *nodes_to_count)
+{
+ return list_lru_count_nodemask_memcg(lru, nodes_to_count, NULL);
+}
static inline unsigned long list_lru_count(struct list_lru *lru)
{
return list_lru_count_nodemask(lru, &lru->active_nodes);
}
-
typedef enum lru_status
(*list_lru_walk_cb)(struct list_head *item, spinlock_t *lock, void *cb_arg);
typedef void (*list_lru_dispose_cb)(struct list_head *dispose_list);
-unsigned long
-list_lru_walk_nodemask(struct list_lru *lru, list_lru_walk_cb isolate,
- void *cb_arg, unsigned long nr_to_walk, nodemask_t *nodes_to_walk);
+unsigned long list_lru_walk_nodemask_memcg(struct list_lru *lru,
+ list_lru_walk_cb isolate, void *cb_arg, unsigned long nr_to_walk,
+ nodemask_t *nodes_to_walk, struct mem_cgroup *memcg);
+
+static inline unsigned long list_lru_walk_nodemask(struct list_lru *lru,
+ list_lru_walk_cb isolate, void *cb_arg, unsigned long nr_to_walk,
+ nodemask_t *nodes_to_walk)
+{
+ return list_lru_walk_nodemask_memcg(lru, isolate, cb_arg, nr_to_walk,
+ &lru->active_nodes, NULL);
+}
static inline unsigned long
list_lru_walk(struct list_lru *lru, list_lru_walk_cb isolate,
diff --git a/include/linux/memcontrol.h b/include/linux/memcontrol.h
index 50f199f..3eeece8 100644
--- a/include/linux/memcontrol.h
+++ b/include/linux/memcontrol.h
@@ -593,6 +593,8 @@ static inline bool memcg_kmem_is_active(struct mem_cgroup *memcg)
#define for_each_memcg_cache_index(_idx) \
for (; NULL; )
+#define memcg_limited_groups_array_size 0
+
static inline bool memcg_kmem_enabled(void)
{
return false;
diff --git a/lib/list_lru.c b/lib/list_lru.c
index a5753b2..f3a37f5 100644
--- a/lib/list_lru.c
+++ b/lib/list_lru.c
@@ -72,6 +72,23 @@ memcg_kmem_lru_of_page(struct list_lru *lru, struct page *page)
return lru_node_of_index(lru, memcg_id, nid);
}
+/*
+ * This helper will loop through all node-data in the LRU, either global or
+ * per-memcg. If memcg is either not present or not used,
+ * memcg_limited_groups_array_size will be 0. _idx starts at -1, and it will
+ * still be allowed to execute once.
+ *
+ * We convention that for _idx = -1, the global node info should be used.
+ * After that, we will go through each of the memcgs, starting at 0.
+ *
+ * We don't need any kind of locking for the loop because
+ * memcg_limited_groups_array_size can only grow, gaining new fields at the
+ * end. The old ones are just copied, and any interesting manipulation happen
+ * in the node list itself, and we already lock the list.
+ */
+#define for_each_memcg_lru_index(_idx) \
+ for ((_idx) = -1; ((_idx) < memcg_limited_groups_array_size); (_idx)++)
+
int
list_lru_add(
struct list_lru *lru,
@@ -131,13 +148,29 @@ list_lru_del(
EXPORT_SYMBOL_GPL(list_lru_del);
unsigned long
-list_lru_count_nodemask(struct list_lru *lru, nodemask_t *nodes_to_count)
+list_lru_count_nodemask_memcg(
+ struct list_lru *lru,
+ nodemask_t *nodes_to_count,
+ struct mem_cgroup *memcg)
{
long count = 0;
int nid;
+ nodemask_t nodes;
+ int memcg_id = -1;
+
+ if (memcg && memcg_kmem_is_active(memcg))
+ memcg_id = memcg_cache_id(memcg);
+ /*
+ * Conservative code can call this setting nodes with node_setall.
+ * This will generate an out of bound access for memcg.
+ */
+ nodes_and(nodes, *nodes_to_count, node_online_map);
- for_each_node_mask(nid, *nodes_to_count) {
- struct list_lru_node *nlru = &lru->node[nid];
+ for_each_node_mask(nid, nodes) {
+ struct list_lru_node *nlru;
+ nlru = lru_node_of_index(lru, memcg_id, nid);
+ if (!nlru)
+ continue;
spin_lock(&nlru->lock);
BUG_ON(nlru->nr_items < 0);
@@ -147,17 +180,17 @@ list_lru_count_nodemask(struct list_lru *lru, nodemask_t *nodes_to_count)
return count;
}
-EXPORT_SYMBOL_GPL(list_lru_count_nodemask);
+EXPORT_SYMBOL_GPL(list_lru_count_nodemask_memcg);
static unsigned long
list_lru_walk_node(
struct list_lru *lru,
+ struct list_lru_node *nlru,
int nid,
list_lru_walk_cb isolate,
void *cb_arg,
unsigned long *nr_to_walk)
{
- struct list_lru_node *nlru = &lru->node[nid];
struct list_head *item, *n;
unsigned long isolated = 0;
@@ -197,25 +230,41 @@ restart:
}
unsigned long
-list_lru_walk_nodemask(
- struct list_lru *lru,
- list_lru_walk_cb isolate,
- void *cb_arg,
- unsigned long nr_to_walk,
- nodemask_t *nodes_to_walk)
+list_lru_walk_nodemask_memcg(
+ struct list_lru *lru,
+ list_lru_walk_cb isolate,
+ void *cb_arg,
+ unsigned long nr_to_walk,
+ nodemask_t *nodes_to_walk,
+ struct mem_cgroup *memcg)
{
long isolated = 0;
int nid;
+ nodemask_t nodes;
+ int memcg_id = -1;
+ struct list_lru_node *nlru;
- for_each_node_mask(nid, *nodes_to_walk) {
- isolated += list_lru_walk_node(lru, nid, isolate,
+ if (memcg && memcg_kmem_is_active(memcg))
+ memcg_id = memcg_cache_id(memcg);
+ /*
+ * Conservative code can call this setting nodes with node_setall.
+ * This will generate an out of bound access for memcg.
+ */
+ nodes_and(nodes, *nodes_to_walk, node_online_map);
+
+ for_each_node_mask(nid, nodes) {
+ nlru = lru_node_of_index(lru, memcg_id, nid);
+ if (!nlru)
+ continue;
+
+ isolated += list_lru_walk_node(lru, nlru, nid, isolate,
cb_arg, &nr_to_walk);
if (nr_to_walk <= 0)
break;
}
return isolated;
}
-EXPORT_SYMBOL_GPL(list_lru_walk_nodemask);
+EXPORT_SYMBOL_GPL(list_lru_walk_nodemask_memcg);
static unsigned long
list_lru_dispose_all_node(
@@ -223,23 +272,34 @@ list_lru_dispose_all_node(
int nid,
list_lru_dispose_cb dispose)
{
- struct list_lru_node *nlru = &lru->node[nid];
+ struct list_lru_node *nlru;
LIST_HEAD(dispose_list);
unsigned long disposed = 0;
+ int idx;
- spin_lock(&nlru->lock);
- while (!list_empty(&nlru->list)) {
- list_splice_init(&nlru->list, &dispose_list);
- disposed += nlru->nr_items;
- nlru->nr_items = 0;
- node_clear(nid, lru->active_nodes);
- spin_unlock(&nlru->lock);
-
- dispose(&dispose_list);
+ for_each_memcg_lru_index(idx) {
+ nlru = lru_node_of_index(lru, idx, nid);
+ if (!nlru)
+ continue;
spin_lock(&nlru->lock);
+ while (!list_empty(&nlru->list)) {
+ list_splice_init(&nlru->list, &dispose_list);
+
+ if (atomic_long_sub_and_test(nlru->nr_items,
+ &lru->node_totals[nid]))
+ node_clear(nid, lru->active_nodes);
+ disposed += nlru->nr_items;
+ nlru->nr_items = 0;
+ spin_unlock(&nlru->lock);
+
+ dispose(&dispose_list);
+
+ spin_lock(&nlru->lock);
+ }
+ spin_unlock(&nlru->lock);
}
- spin_unlock(&nlru->lock);
+
return disposed;
}
--
1.8.1.4
^ permalink raw reply related [flat|nested] 151+ messages in thread* [PATCH v6 24/31] list_lru: per-memcg walks
@ 2013-05-12 18:13 ` Glauber Costa
0 siblings, 0 replies; 151+ messages in thread
From: Glauber Costa @ 2013-05-12 18:13 UTC (permalink / raw)
To: linux-mm
Cc: cgroups, Andrew Morton, Greg Thelen, kamezawa.hiroyu,
Michal Hocko, Johannes Weiner, linux-fsdevel, Dave Chinner,
Glauber Costa, Dave Chinner, Mel Gorman, Rik van Riel,
Hugh Dickins
This patch extend the list_lru interfaces to allow for a memcg
parameter. Because most of its users won't need it, instead of
modifying the function signatures we create a new set of _memcg()
functions and write the old API ontop of that.
Signed-off-by: Glauber Costa <glommer@openvz.org>
Cc: Dave Chinner <dchinner@redhat.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Rik van Riel <riel@redhat.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Michal Hocko <mhocko@suse.cz>
Cc: Hugh Dickins <hughd@google.com>
Cc: Kamezawa Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
---
include/linux/list_lru.h | 26 ++++++++---
include/linux/memcontrol.h | 2 +
lib/list_lru.c | 110 ++++++++++++++++++++++++++++++++++-----------
3 files changed, 107 insertions(+), 31 deletions(-)
diff --git a/include/linux/list_lru.h b/include/linux/list_lru.h
index f6756fb..9e6bbb1 100644
--- a/include/linux/list_lru.h
+++ b/include/linux/list_lru.h
@@ -99,23 +99,37 @@ static inline int list_lru_init_memcg(struct list_lru *lru)
int list_lru_add(struct list_lru *lru, struct list_head *item);
int list_lru_del(struct list_lru *lru, struct list_head *item);
-unsigned long
-list_lru_count_nodemask(struct list_lru *lru, nodemask_t *nodes_to_count);
+
+unsigned long list_lru_count_nodemask_memcg(struct list_lru *lru,
+ nodemask_t *nodes_to_count, struct mem_cgroup *memcg);
+
+static inline unsigned long
+list_lru_count_nodemask(struct list_lru *lru, nodemask_t *nodes_to_count)
+{
+ return list_lru_count_nodemask_memcg(lru, nodes_to_count, NULL);
+}
static inline unsigned long list_lru_count(struct list_lru *lru)
{
return list_lru_count_nodemask(lru, &lru->active_nodes);
}
-
typedef enum lru_status
(*list_lru_walk_cb)(struct list_head *item, spinlock_t *lock, void *cb_arg);
typedef void (*list_lru_dispose_cb)(struct list_head *dispose_list);
-unsigned long
-list_lru_walk_nodemask(struct list_lru *lru, list_lru_walk_cb isolate,
- void *cb_arg, unsigned long nr_to_walk, nodemask_t *nodes_to_walk);
+unsigned long list_lru_walk_nodemask_memcg(struct list_lru *lru,
+ list_lru_walk_cb isolate, void *cb_arg, unsigned long nr_to_walk,
+ nodemask_t *nodes_to_walk, struct mem_cgroup *memcg);
+
+static inline unsigned long list_lru_walk_nodemask(struct list_lru *lru,
+ list_lru_walk_cb isolate, void *cb_arg, unsigned long nr_to_walk,
+ nodemask_t *nodes_to_walk)
+{
+ return list_lru_walk_nodemask_memcg(lru, isolate, cb_arg, nr_to_walk,
+ &lru->active_nodes, NULL);
+}
static inline unsigned long
list_lru_walk(struct list_lru *lru, list_lru_walk_cb isolate,
diff --git a/include/linux/memcontrol.h b/include/linux/memcontrol.h
index 50f199f..3eeece8 100644
--- a/include/linux/memcontrol.h
+++ b/include/linux/memcontrol.h
@@ -593,6 +593,8 @@ static inline bool memcg_kmem_is_active(struct mem_cgroup *memcg)
#define for_each_memcg_cache_index(_idx) \
for (; NULL; )
+#define memcg_limited_groups_array_size 0
+
static inline bool memcg_kmem_enabled(void)
{
return false;
diff --git a/lib/list_lru.c b/lib/list_lru.c
index a5753b2..f3a37f5 100644
--- a/lib/list_lru.c
+++ b/lib/list_lru.c
@@ -72,6 +72,23 @@ memcg_kmem_lru_of_page(struct list_lru *lru, struct page *page)
return lru_node_of_index(lru, memcg_id, nid);
}
+/*
+ * This helper will loop through all node-data in the LRU, either global or
+ * per-memcg. If memcg is either not present or not used,
+ * memcg_limited_groups_array_size will be 0. _idx starts at -1, and it will
+ * still be allowed to execute once.
+ *
+ * We convention that for _idx = -1, the global node info should be used.
+ * After that, we will go through each of the memcgs, starting at 0.
+ *
+ * We don't need any kind of locking for the loop because
+ * memcg_limited_groups_array_size can only grow, gaining new fields at the
+ * end. The old ones are just copied, and any interesting manipulation happen
+ * in the node list itself, and we already lock the list.
+ */
+#define for_each_memcg_lru_index(_idx) \
+ for ((_idx) = -1; ((_idx) < memcg_limited_groups_array_size); (_idx)++)
+
int
list_lru_add(
struct list_lru *lru,
@@ -131,13 +148,29 @@ list_lru_del(
EXPORT_SYMBOL_GPL(list_lru_del);
unsigned long
-list_lru_count_nodemask(struct list_lru *lru, nodemask_t *nodes_to_count)
+list_lru_count_nodemask_memcg(
+ struct list_lru *lru,
+ nodemask_t *nodes_to_count,
+ struct mem_cgroup *memcg)
{
long count = 0;
int nid;
+ nodemask_t nodes;
+ int memcg_id = -1;
+
+ if (memcg && memcg_kmem_is_active(memcg))
+ memcg_id = memcg_cache_id(memcg);
+ /*
+ * Conservative code can call this setting nodes with node_setall.
+ * This will generate an out of bound access for memcg.
+ */
+ nodes_and(nodes, *nodes_to_count, node_online_map);
- for_each_node_mask(nid, *nodes_to_count) {
- struct list_lru_node *nlru = &lru->node[nid];
+ for_each_node_mask(nid, nodes) {
+ struct list_lru_node *nlru;
+ nlru = lru_node_of_index(lru, memcg_id, nid);
+ if (!nlru)
+ continue;
spin_lock(&nlru->lock);
BUG_ON(nlru->nr_items < 0);
@@ -147,17 +180,17 @@ list_lru_count_nodemask(struct list_lru *lru, nodemask_t *nodes_to_count)
return count;
}
-EXPORT_SYMBOL_GPL(list_lru_count_nodemask);
+EXPORT_SYMBOL_GPL(list_lru_count_nodemask_memcg);
static unsigned long
list_lru_walk_node(
struct list_lru *lru,
+ struct list_lru_node *nlru,
int nid,
list_lru_walk_cb isolate,
void *cb_arg,
unsigned long *nr_to_walk)
{
- struct list_lru_node *nlru = &lru->node[nid];
struct list_head *item, *n;
unsigned long isolated = 0;
@@ -197,25 +230,41 @@ restart:
}
unsigned long
-list_lru_walk_nodemask(
- struct list_lru *lru,
- list_lru_walk_cb isolate,
- void *cb_arg,
- unsigned long nr_to_walk,
- nodemask_t *nodes_to_walk)
+list_lru_walk_nodemask_memcg(
+ struct list_lru *lru,
+ list_lru_walk_cb isolate,
+ void *cb_arg,
+ unsigned long nr_to_walk,
+ nodemask_t *nodes_to_walk,
+ struct mem_cgroup *memcg)
{
long isolated = 0;
int nid;
+ nodemask_t nodes;
+ int memcg_id = -1;
+ struct list_lru_node *nlru;
- for_each_node_mask(nid, *nodes_to_walk) {
- isolated += list_lru_walk_node(lru, nid, isolate,
+ if (memcg && memcg_kmem_is_active(memcg))
+ memcg_id = memcg_cache_id(memcg);
+ /*
+ * Conservative code can call this setting nodes with node_setall.
+ * This will generate an out of bound access for memcg.
+ */
+ nodes_and(nodes, *nodes_to_walk, node_online_map);
+
+ for_each_node_mask(nid, nodes) {
+ nlru = lru_node_of_index(lru, memcg_id, nid);
+ if (!nlru)
+ continue;
+
+ isolated += list_lru_walk_node(lru, nlru, nid, isolate,
cb_arg, &nr_to_walk);
if (nr_to_walk <= 0)
break;
}
return isolated;
}
-EXPORT_SYMBOL_GPL(list_lru_walk_nodemask);
+EXPORT_SYMBOL_GPL(list_lru_walk_nodemask_memcg);
static unsigned long
list_lru_dispose_all_node(
@@ -223,23 +272,34 @@ list_lru_dispose_all_node(
int nid,
list_lru_dispose_cb dispose)
{
- struct list_lru_node *nlru = &lru->node[nid];
+ struct list_lru_node *nlru;
LIST_HEAD(dispose_list);
unsigned long disposed = 0;
+ int idx;
- spin_lock(&nlru->lock);
- while (!list_empty(&nlru->list)) {
- list_splice_init(&nlru->list, &dispose_list);
- disposed += nlru->nr_items;
- nlru->nr_items = 0;
- node_clear(nid, lru->active_nodes);
- spin_unlock(&nlru->lock);
-
- dispose(&dispose_list);
+ for_each_memcg_lru_index(idx) {
+ nlru = lru_node_of_index(lru, idx, nid);
+ if (!nlru)
+ continue;
spin_lock(&nlru->lock);
+ while (!list_empty(&nlru->list)) {
+ list_splice_init(&nlru->list, &dispose_list);
+
+ if (atomic_long_sub_and_test(nlru->nr_items,
+ &lru->node_totals[nid]))
+ node_clear(nid, lru->active_nodes);
+ disposed += nlru->nr_items;
+ nlru->nr_items = 0;
+ spin_unlock(&nlru->lock);
+
+ dispose(&dispose_list);
+
+ spin_lock(&nlru->lock);
+ }
+ spin_unlock(&nlru->lock);
}
- spin_unlock(&nlru->lock);
+
return disposed;
}
--
1.8.1.4
^ permalink raw reply related [flat|nested] 151+ messages in thread* [PATCH v6 24/31] list_lru: per-memcg walks
@ 2013-05-12 18:13 ` Glauber Costa
0 siblings, 0 replies; 151+ messages in thread
From: Glauber Costa @ 2013-05-12 18:13 UTC (permalink / raw)
To: linux-mm
Cc: cgroups, Andrew Morton, Greg Thelen, kamezawa.hiroyu,
Michal Hocko, Johannes Weiner, linux-fsdevel, Dave Chinner,
Glauber Costa, Dave Chinner, Mel Gorman, Rik van Riel,
Hugh Dickins
This patch extend the list_lru interfaces to allow for a memcg
parameter. Because most of its users won't need it, instead of
modifying the function signatures we create a new set of _memcg()
functions and write the old API ontop of that.
Signed-off-by: Glauber Costa <glommer@openvz.org>
Cc: Dave Chinner <dchinner@redhat.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Rik van Riel <riel@redhat.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Michal Hocko <mhocko@suse.cz>
Cc: Hugh Dickins <hughd@google.com>
Cc: Kamezawa Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
---
include/linux/list_lru.h | 26 ++++++++---
include/linux/memcontrol.h | 2 +
lib/list_lru.c | 110 ++++++++++++++++++++++++++++++++++-----------
3 files changed, 107 insertions(+), 31 deletions(-)
diff --git a/include/linux/list_lru.h b/include/linux/list_lru.h
index f6756fb..9e6bbb1 100644
--- a/include/linux/list_lru.h
+++ b/include/linux/list_lru.h
@@ -99,23 +99,37 @@ static inline int list_lru_init_memcg(struct list_lru *lru)
int list_lru_add(struct list_lru *lru, struct list_head *item);
int list_lru_del(struct list_lru *lru, struct list_head *item);
-unsigned long
-list_lru_count_nodemask(struct list_lru *lru, nodemask_t *nodes_to_count);
+
+unsigned long list_lru_count_nodemask_memcg(struct list_lru *lru,
+ nodemask_t *nodes_to_count, struct mem_cgroup *memcg);
+
+static inline unsigned long
+list_lru_count_nodemask(struct list_lru *lru, nodemask_t *nodes_to_count)
+{
+ return list_lru_count_nodemask_memcg(lru, nodes_to_count, NULL);
+}
static inline unsigned long list_lru_count(struct list_lru *lru)
{
return list_lru_count_nodemask(lru, &lru->active_nodes);
}
-
typedef enum lru_status
(*list_lru_walk_cb)(struct list_head *item, spinlock_t *lock, void *cb_arg);
typedef void (*list_lru_dispose_cb)(struct list_head *dispose_list);
-unsigned long
-list_lru_walk_nodemask(struct list_lru *lru, list_lru_walk_cb isolate,
- void *cb_arg, unsigned long nr_to_walk, nodemask_t *nodes_to_walk);
+unsigned long list_lru_walk_nodemask_memcg(struct list_lru *lru,
+ list_lru_walk_cb isolate, void *cb_arg, unsigned long nr_to_walk,
+ nodemask_t *nodes_to_walk, struct mem_cgroup *memcg);
+
+static inline unsigned long list_lru_walk_nodemask(struct list_lru *lru,
+ list_lru_walk_cb isolate, void *cb_arg, unsigned long nr_to_walk,
+ nodemask_t *nodes_to_walk)
+{
+ return list_lru_walk_nodemask_memcg(lru, isolate, cb_arg, nr_to_walk,
+ &lru->active_nodes, NULL);
+}
static inline unsigned long
list_lru_walk(struct list_lru *lru, list_lru_walk_cb isolate,
diff --git a/include/linux/memcontrol.h b/include/linux/memcontrol.h
index 50f199f..3eeece8 100644
--- a/include/linux/memcontrol.h
+++ b/include/linux/memcontrol.h
@@ -593,6 +593,8 @@ static inline bool memcg_kmem_is_active(struct mem_cgroup *memcg)
#define for_each_memcg_cache_index(_idx) \
for (; NULL; )
+#define memcg_limited_groups_array_size 0
+
static inline bool memcg_kmem_enabled(void)
{
return false;
diff --git a/lib/list_lru.c b/lib/list_lru.c
index a5753b2..f3a37f5 100644
--- a/lib/list_lru.c
+++ b/lib/list_lru.c
@@ -72,6 +72,23 @@ memcg_kmem_lru_of_page(struct list_lru *lru, struct page *page)
return lru_node_of_index(lru, memcg_id, nid);
}
+/*
+ * This helper will loop through all node-data in the LRU, either global or
+ * per-memcg. If memcg is either not present or not used,
+ * memcg_limited_groups_array_size will be 0. _idx starts at -1, and it will
+ * still be allowed to execute once.
+ *
+ * We convention that for _idx = -1, the global node info should be used.
+ * After that, we will go through each of the memcgs, starting at 0.
+ *
+ * We don't need any kind of locking for the loop because
+ * memcg_limited_groups_array_size can only grow, gaining new fields at the
+ * end. The old ones are just copied, and any interesting manipulation happen
+ * in the node list itself, and we already lock the list.
+ */
+#define for_each_memcg_lru_index(_idx) \
+ for ((_idx) = -1; ((_idx) < memcg_limited_groups_array_size); (_idx)++)
+
int
list_lru_add(
struct list_lru *lru,
@@ -131,13 +148,29 @@ list_lru_del(
EXPORT_SYMBOL_GPL(list_lru_del);
unsigned long
-list_lru_count_nodemask(struct list_lru *lru, nodemask_t *nodes_to_count)
+list_lru_count_nodemask_memcg(
+ struct list_lru *lru,
+ nodemask_t *nodes_to_count,
+ struct mem_cgroup *memcg)
{
long count = 0;
int nid;
+ nodemask_t nodes;
+ int memcg_id = -1;
+
+ if (memcg && memcg_kmem_is_active(memcg))
+ memcg_id = memcg_cache_id(memcg);
+ /*
+ * Conservative code can call this setting nodes with node_setall.
+ * This will generate an out of bound access for memcg.
+ */
+ nodes_and(nodes, *nodes_to_count, node_online_map);
- for_each_node_mask(nid, *nodes_to_count) {
- struct list_lru_node *nlru = &lru->node[nid];
+ for_each_node_mask(nid, nodes) {
+ struct list_lru_node *nlru;
+ nlru = lru_node_of_index(lru, memcg_id, nid);
+ if (!nlru)
+ continue;
spin_lock(&nlru->lock);
BUG_ON(nlru->nr_items < 0);
@@ -147,17 +180,17 @@ list_lru_count_nodemask(struct list_lru *lru, nodemask_t *nodes_to_count)
return count;
}
-EXPORT_SYMBOL_GPL(list_lru_count_nodemask);
+EXPORT_SYMBOL_GPL(list_lru_count_nodemask_memcg);
static unsigned long
list_lru_walk_node(
struct list_lru *lru,
+ struct list_lru_node *nlru,
int nid,
list_lru_walk_cb isolate,
void *cb_arg,
unsigned long *nr_to_walk)
{
- struct list_lru_node *nlru = &lru->node[nid];
struct list_head *item, *n;
unsigned long isolated = 0;
@@ -197,25 +230,41 @@ restart:
}
unsigned long
-list_lru_walk_nodemask(
- struct list_lru *lru,
- list_lru_walk_cb isolate,
- void *cb_arg,
- unsigned long nr_to_walk,
- nodemask_t *nodes_to_walk)
+list_lru_walk_nodemask_memcg(
+ struct list_lru *lru,
+ list_lru_walk_cb isolate,
+ void *cb_arg,
+ unsigned long nr_to_walk,
+ nodemask_t *nodes_to_walk,
+ struct mem_cgroup *memcg)
{
long isolated = 0;
int nid;
+ nodemask_t nodes;
+ int memcg_id = -1;
+ struct list_lru_node *nlru;
- for_each_node_mask(nid, *nodes_to_walk) {
- isolated += list_lru_walk_node(lru, nid, isolate,
+ if (memcg && memcg_kmem_is_active(memcg))
+ memcg_id = memcg_cache_id(memcg);
+ /*
+ * Conservative code can call this setting nodes with node_setall.
+ * This will generate an out of bound access for memcg.
+ */
+ nodes_and(nodes, *nodes_to_walk, node_online_map);
+
+ for_each_node_mask(nid, nodes) {
+ nlru = lru_node_of_index(lru, memcg_id, nid);
+ if (!nlru)
+ continue;
+
+ isolated += list_lru_walk_node(lru, nlru, nid, isolate,
cb_arg, &nr_to_walk);
if (nr_to_walk <= 0)
break;
}
return isolated;
}
-EXPORT_SYMBOL_GPL(list_lru_walk_nodemask);
+EXPORT_SYMBOL_GPL(list_lru_walk_nodemask_memcg);
static unsigned long
list_lru_dispose_all_node(
@@ -223,23 +272,34 @@ list_lru_dispose_all_node(
int nid,
list_lru_dispose_cb dispose)
{
- struct list_lru_node *nlru = &lru->node[nid];
+ struct list_lru_node *nlru;
LIST_HEAD(dispose_list);
unsigned long disposed = 0;
+ int idx;
- spin_lock(&nlru->lock);
- while (!list_empty(&nlru->list)) {
- list_splice_init(&nlru->list, &dispose_list);
- disposed += nlru->nr_items;
- nlru->nr_items = 0;
- node_clear(nid, lru->active_nodes);
- spin_unlock(&nlru->lock);
-
- dispose(&dispose_list);
+ for_each_memcg_lru_index(idx) {
+ nlru = lru_node_of_index(lru, idx, nid);
+ if (!nlru)
+ continue;
spin_lock(&nlru->lock);
+ while (!list_empty(&nlru->list)) {
+ list_splice_init(&nlru->list, &dispose_list);
+
+ if (atomic_long_sub_and_test(nlru->nr_items,
+ &lru->node_totals[nid]))
+ node_clear(nid, lru->active_nodes);
+ disposed += nlru->nr_items;
+ nlru->nr_items = 0;
+ spin_unlock(&nlru->lock);
+
+ dispose(&dispose_list);
+
+ spin_lock(&nlru->lock);
+ }
+ spin_unlock(&nlru->lock);
}
- spin_unlock(&nlru->lock);
+
return disposed;
}
--
1.8.1.4
--
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^ permalink raw reply related [flat|nested] 151+ messages in thread
* [PATCH v6 25/31] memcg: per-memcg kmem shrinking
2013-05-12 18:13 ` Glauber Costa
(?)
@ 2013-05-12 18:13 ` Glauber Costa
-1 siblings, 0 replies; 151+ messages in thread
From: Glauber Costa @ 2013-05-12 18:13 UTC (permalink / raw)
To: linux-mm
Cc: cgroups, Andrew Morton, Greg Thelen, kamezawa.hiroyu,
Michal Hocko, Johannes Weiner, linux-fsdevel, Dave Chinner,
Glauber Costa, Dave Chinner, Mel Gorman, Rik van Riel,
Hugh Dickins
If the kernel limit is smaller than the user limit, we will have
situations in which our allocations fail but freeing user pages will buy
us nothing. In those, we would like to call a specialized memcg
reclaimer that only frees kernel memory and leave the user memory alone.
Those are also expected to fail when we account memcg->kmem, instead of
when we account memcg->res. Based on that, this patch implements a
memcg-specific reclaimer, that only shrinks kernel objects, withouth
touching user pages.
There might be situations in which there are plenty of objects to
shrink, but we can't do it because the __GFP_FS flag is not set.
Although they can happen with user pages, they are a lot more common
with fs-metadata: this is the case with almost all inode allocation.
Those allocations are, however, capable of waiting. So we can just span
a worker, let it finish its job and proceed with the allocation. As slow
as it is, at this point we are already past any hopes anyway.
[ v2: moved congestion_wait call to vmscan.c ]
Signed-off-by: Glauber Costa <glommer@openvz.org>
Cc: Dave Chinner <dchinner@redhat.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Rik van Riel <riel@redhat.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Michal Hocko <mhocko@suse.cz>
Cc: Hugh Dickins <hughd@google.com>
Cc: Kamezawa Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
---
include/linux/swap.h | 2 +
mm/memcontrol.c | 180 ++++++++++++++++++++++++++++++++++++++++-----------
mm/vmscan.c | 44 ++++++++++++-
3 files changed, 187 insertions(+), 39 deletions(-)
diff --git a/include/linux/swap.h b/include/linux/swap.h
index ca031f7..5a0ef45 100644
--- a/include/linux/swap.h
+++ b/include/linux/swap.h
@@ -268,6 +268,8 @@ extern unsigned long try_to_free_pages(struct zonelist *zonelist, int order,
extern int __isolate_lru_page(struct page *page, isolate_mode_t mode);
extern unsigned long try_to_free_mem_cgroup_pages(struct mem_cgroup *mem,
gfp_t gfp_mask, bool noswap);
+extern unsigned long try_to_free_mem_cgroup_kmem(struct mem_cgroup *mem,
+ gfp_t gfp_mask);
extern unsigned long mem_cgroup_shrink_node_zone(struct mem_cgroup *mem,
gfp_t gfp_mask, bool noswap,
struct zone *zone,
diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index 4bf6738..c563550 100644
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -382,7 +382,8 @@ struct mem_cgroup {
atomic_t numainfo_events;
atomic_t numainfo_updating;
#endif
-
+ /* when kmem shrinkers can sleep but can't proceed due to context */
+ struct work_struct kmemcg_shrink_work;
/*
* Per cgroup active and inactive list, similar to the
* per zone LRU lists.
@@ -448,11 +449,14 @@ static inline void memcg_dangling_free(struct mem_cgroup *memcg) {}
static inline void memcg_dangling_add(struct mem_cgroup *memcg) {}
#endif
+static DEFINE_MUTEX(set_limit_mutex);
+
/* internal only representation about the status of kmem accounting. */
enum {
KMEM_ACCOUNTED_ACTIVE = 0, /* accounted by this cgroup itself */
KMEM_ACCOUNTED_ACTIVATED, /* static key enabled. */
KMEM_ACCOUNTED_DEAD, /* dead memcg with pending kmem charges */
+ KMEM_MAY_SHRINK, /* kmem limit < mem limit, shrink kmem only */
};
/* We account when limit is on, but only after call sites are patched */
@@ -491,6 +495,31 @@ static bool memcg_kmem_test_and_clear_dead(struct mem_cgroup *memcg)
return test_and_clear_bit(KMEM_ACCOUNTED_DEAD,
&memcg->kmem_account_flags);
}
+
+/*
+ * If the kernel limit is smaller than the user limit, we will have situations
+ * in which our allocations fail but freeing user pages will buy us nothing.
+ * In those, we would like to call a specialized memcg reclaimer that only
+ * frees kernel memory and leave the user memory alone.
+ *
+ * This test exists so we can differentiate between those. Everytime one of the
+ * limits is updated, we need to run it. The set_limit_mutex must be held, so
+ * they don't change again.
+ */
+static void memcg_update_shrink_status(struct mem_cgroup *memcg)
+{
+ mutex_lock(&set_limit_mutex);
+ if (res_counter_read_u64(&memcg->kmem, RES_LIMIT) <
+ res_counter_read_u64(&memcg->res, RES_LIMIT))
+ set_bit(KMEM_MAY_SHRINK, &memcg->kmem_account_flags);
+ else
+ clear_bit(KMEM_MAY_SHRINK, &memcg->kmem_account_flags);
+ mutex_unlock(&set_limit_mutex);
+}
+#else
+static void memcg_update_shrink_status(struct mem_cgroup *memcg)
+{
+}
#endif
/* Stuffs for move charges at task migration. */
@@ -3013,8 +3042,6 @@ static void __mem_cgroup_commit_charge(struct mem_cgroup *memcg,
memcg_check_events(memcg, page);
}
-static DEFINE_MUTEX(set_limit_mutex);
-
#ifdef CONFIG_MEMCG_KMEM
static inline bool memcg_can_account_kmem(struct mem_cgroup *memcg)
{
@@ -3056,16 +3083,91 @@ static int mem_cgroup_slabinfo_read(struct cgroup *cont, struct cftype *cft,
}
#endif
+/*
+ * During the creation a new cache, we need to disable our accounting mechanism
+ * altogether. This is true even if we are not creating, but rather just
+ * enqueing new caches to be created.
+ *
+ * This is because that process will trigger allocations; some visible, like
+ * explicit kmallocs to auxiliary data structures, name strings and internal
+ * cache structures; some well concealed, like INIT_WORK() that can allocate
+ * objects during debug.
+ *
+ * If any allocation happens during memcg_kmem_get_cache, we will recurse back
+ * to it. This may not be a bounded recursion: since the first cache creation
+ * failed to complete (waiting on the allocation), we'll just try to create the
+ * cache again, failing at the same point.
+ *
+ * memcg_kmem_get_cache is prepared to abort after seeing a positive count of
+ * memcg_kmem_skip_account. So we enclose anything that might allocate memory
+ * inside the following two functions.
+ */
+static inline void memcg_stop_kmem_account(void)
+{
+ VM_BUG_ON(!current->mm);
+ current->memcg_kmem_skip_account++;
+}
+
+static inline void memcg_resume_kmem_account(void)
+{
+ VM_BUG_ON(!current->mm);
+ current->memcg_kmem_skip_account--;
+}
+
+static int memcg_try_charge_kmem(struct mem_cgroup *memcg, gfp_t gfp, u64 size)
+{
+ int retries = MEM_CGROUP_RECLAIM_RETRIES;
+ struct res_counter *fail_res;
+ int ret;
+
+ do {
+ ret = res_counter_charge(&memcg->kmem, size, &fail_res);
+ if (!ret)
+ return ret;
+
+ if (!(gfp & __GFP_WAIT))
+ return ret;
+
+ /*
+ * We will try to shrink kernel memory present in caches. We
+ * are sure that we can wait, so we will. The duration of our
+ * wait is determined by congestion, the same way as vmscan.c
+ *
+ * If we are in FS context, though, then although we can wait,
+ * we cannot call the shrinkers. Most fs shrinkers (which
+ * comprises most of our kmem data) will not run without
+ * __GFP_FS since they can deadlock. The solution is to
+ * synchronously run that in a different context.
+ */
+ if (!(gfp & __GFP_FS)) {
+ /*
+ * we are already short on memory, every queue
+ * allocation is likely to fail
+ */
+ memcg_stop_kmem_account();
+ schedule_work(&memcg->kmemcg_shrink_work);
+ flush_work(&memcg->kmemcg_shrink_work);
+ memcg_resume_kmem_account();
+ } else
+ try_to_free_mem_cgroup_kmem(memcg, gfp);
+ } while (retries--);
+
+ return ret;
+}
+
static int memcg_charge_kmem(struct mem_cgroup *memcg, gfp_t gfp, u64 size)
{
struct res_counter *fail_res;
struct mem_cgroup *_memcg;
int ret = 0;
bool may_oom;
+ bool kmem_first = test_bit(KMEM_MAY_SHRINK, &memcg->kmem_account_flags);
- ret = res_counter_charge(&memcg->kmem, size, &fail_res);
- if (ret)
- return ret;
+ if (kmem_first) {
+ ret = memcg_try_charge_kmem(memcg, gfp, size);
+ if (ret)
+ return ret;
+ }
/*
* Conditions under which we can wait for the oom_killer. Those are
@@ -3098,12 +3200,41 @@ static int memcg_charge_kmem(struct mem_cgroup *memcg, gfp_t gfp, u64 size)
res_counter_charge_nofail(&memcg->memsw, size,
&fail_res);
ret = 0;
- } else if (ret)
+ if (kmem_first)
+ res_counter_charge_nofail(&memcg->kmem, size, &fail_res);
+ } else if (ret && kmem_first)
res_counter_uncharge(&memcg->kmem, size);
+ if (!ret && !kmem_first) {
+ ret = res_counter_charge(&memcg->kmem, size, &fail_res);
+ if (!ret)
+ return ret;
+
+ res_counter_uncharge(&memcg->res, size);
+ if (do_swap_account)
+ res_counter_uncharge(&memcg->memsw, size);
+ }
+
return ret;
}
+/*
+ * There might be situations in which there are plenty of objects to shrink,
+ * but we can't do it because the __GFP_FS flag is not set. This is the case
+ * with almost all inode allocation. They do are, however, capable of waiting.
+ * So we can just span a worker, let it finish its job and proceed with the
+ * allocation. As slow as it is, at this point we are already past any hopes
+ * anyway.
+ */
+static void kmemcg_shrink_work_fn(struct work_struct *w)
+{
+ struct mem_cgroup *memcg;
+
+ memcg = container_of(w, struct mem_cgroup, kmemcg_shrink_work);
+ try_to_free_mem_cgroup_kmem(memcg, GFP_KERNEL);
+}
+
+
static void memcg_uncharge_kmem(struct mem_cgroup *memcg, u64 size)
{
res_counter_uncharge(&memcg->res, size);
@@ -3180,6 +3311,7 @@ int memcg_update_cache_sizes(struct mem_cgroup *memcg)
memcg_update_array_size(num + 1);
INIT_LIST_HEAD(&memcg->memcg_slab_caches);
+ INIT_WORK(&memcg->kmemcg_shrink_work, kmemcg_shrink_work_fn);
mutex_init(&memcg->slab_caches_mutex);
return 0;
@@ -3456,37 +3588,6 @@ out:
kfree(s->memcg_params);
}
-/*
- * During the creation a new cache, we need to disable our accounting mechanism
- * altogether. This is true even if we are not creating, but rather just
- * enqueing new caches to be created.
- *
- * This is because that process will trigger allocations; some visible, like
- * explicit kmallocs to auxiliary data structures, name strings and internal
- * cache structures; some well concealed, like INIT_WORK() that can allocate
- * objects during debug.
- *
- * If any allocation happens during memcg_kmem_get_cache, we will recurse back
- * to it. This may not be a bounded recursion: since the first cache creation
- * failed to complete (waiting on the allocation), we'll just try to create the
- * cache again, failing at the same point.
- *
- * memcg_kmem_get_cache is prepared to abort after seeing a positive count of
- * memcg_kmem_skip_account. So we enclose anything that might allocate memory
- * inside the following two functions.
- */
-static inline void memcg_stop_kmem_account(void)
-{
- VM_BUG_ON(!current->mm);
- current->memcg_kmem_skip_account++;
-}
-
-static inline void memcg_resume_kmem_account(void)
-{
- VM_BUG_ON(!current->mm);
- current->memcg_kmem_skip_account--;
-}
-
struct mem_cgroup *mem_cgroup_from_kmem_page(struct page *page)
{
struct page_cgroup *pc;
@@ -5571,6 +5672,9 @@ static int mem_cgroup_write(struct cgroup *cont, struct cftype *cft,
ret = memcg_update_kmem_limit(cont, val);
else
return -EINVAL;
+
+ if (!ret)
+ memcg_update_shrink_status(memcg);
break;
case RES_SOFT_LIMIT:
ret = res_counter_memparse_write_strategy(buffer, &val);
diff --git a/mm/vmscan.c b/mm/vmscan.c
index eb5e67c..731e798 100644
--- a/mm/vmscan.c
+++ b/mm/vmscan.c
@@ -2513,7 +2513,49 @@ unsigned long try_to_free_mem_cgroup_pages(struct mem_cgroup *memcg,
return nr_reclaimed;
}
-#endif
+
+#ifdef CONFIG_MEMCG_KMEM
+/*
+ * This function is called when we are under kmem-specific pressure. It will
+ * only trigger in environments with kmem.limit_in_bytes < limit_in_bytes, IOW,
+ * with a lower kmem allowance than the memory allowance.
+ *
+ * In this situation, freeing user pages from the cgroup won't do us any good.
+ * What we really need is to call the memcg-aware shrinkers, in the hope of
+ * freeing pages holding kmem objects. It may also be that we won't be able to
+ * free any pages, but will get rid of old objects opening up space for new
+ * ones.
+ */
+unsigned long try_to_free_mem_cgroup_kmem(struct mem_cgroup *memcg,
+ gfp_t gfp_mask)
+{
+ long freed;
+
+ struct shrink_control shrink = {
+ .gfp_mask = gfp_mask,
+ .target_mem_cgroup = memcg,
+ };
+
+ if (!(gfp_mask & __GFP_WAIT))
+ return 0;
+
+ /*
+ * memcg pressure is always global */
+ nodes_setall(shrink.nodes_to_scan);
+
+ /*
+ * We haven't scanned any user LRU, so we basically come up with
+ * crafted values of nr_scanned and LRU page (1 and 0 respectively).
+ * This should be enough to tell shrink_slab that the freeing
+ * responsibility is all on himself.
+ */
+ freed = shrink_slab(&shrink, 1, 0);
+ if (!freed)
+ congestion_wait(BLK_RW_ASYNC, HZ/10);
+ return freed;
+}
+#endif /* CONFIG_MEMCG_KMEM */
+#endif /* CONFIG_MEMCG */
static void age_active_anon(struct zone *zone, struct scan_control *sc)
{
--
1.8.1.4
^ permalink raw reply related [flat|nested] 151+ messages in thread* [PATCH v6 25/31] memcg: per-memcg kmem shrinking
@ 2013-05-12 18:13 ` Glauber Costa
0 siblings, 0 replies; 151+ messages in thread
From: Glauber Costa @ 2013-05-12 18:13 UTC (permalink / raw)
To: linux-mm
Cc: cgroups, Andrew Morton, Greg Thelen, kamezawa.hiroyu,
Michal Hocko, Johannes Weiner, linux-fsdevel, Dave Chinner,
Glauber Costa, Dave Chinner, Mel Gorman, Rik van Riel,
Hugh Dickins
If the kernel limit is smaller than the user limit, we will have
situations in which our allocations fail but freeing user pages will buy
us nothing. In those, we would like to call a specialized memcg
reclaimer that only frees kernel memory and leave the user memory alone.
Those are also expected to fail when we account memcg->kmem, instead of
when we account memcg->res. Based on that, this patch implements a
memcg-specific reclaimer, that only shrinks kernel objects, withouth
touching user pages.
There might be situations in which there are plenty of objects to
shrink, but we can't do it because the __GFP_FS flag is not set.
Although they can happen with user pages, they are a lot more common
with fs-metadata: this is the case with almost all inode allocation.
Those allocations are, however, capable of waiting. So we can just span
a worker, let it finish its job and proceed with the allocation. As slow
as it is, at this point we are already past any hopes anyway.
[ v2: moved congestion_wait call to vmscan.c ]
Signed-off-by: Glauber Costa <glommer@openvz.org>
Cc: Dave Chinner <dchinner@redhat.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Rik van Riel <riel@redhat.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Michal Hocko <mhocko@suse.cz>
Cc: Hugh Dickins <hughd@google.com>
Cc: Kamezawa Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
---
include/linux/swap.h | 2 +
mm/memcontrol.c | 180 ++++++++++++++++++++++++++++++++++++++++-----------
mm/vmscan.c | 44 ++++++++++++-
3 files changed, 187 insertions(+), 39 deletions(-)
diff --git a/include/linux/swap.h b/include/linux/swap.h
index ca031f7..5a0ef45 100644
--- a/include/linux/swap.h
+++ b/include/linux/swap.h
@@ -268,6 +268,8 @@ extern unsigned long try_to_free_pages(struct zonelist *zonelist, int order,
extern int __isolate_lru_page(struct page *page, isolate_mode_t mode);
extern unsigned long try_to_free_mem_cgroup_pages(struct mem_cgroup *mem,
gfp_t gfp_mask, bool noswap);
+extern unsigned long try_to_free_mem_cgroup_kmem(struct mem_cgroup *mem,
+ gfp_t gfp_mask);
extern unsigned long mem_cgroup_shrink_node_zone(struct mem_cgroup *mem,
gfp_t gfp_mask, bool noswap,
struct zone *zone,
diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index 4bf6738..c563550 100644
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -382,7 +382,8 @@ struct mem_cgroup {
atomic_t numainfo_events;
atomic_t numainfo_updating;
#endif
-
+ /* when kmem shrinkers can sleep but can't proceed due to context */
+ struct work_struct kmemcg_shrink_work;
/*
* Per cgroup active and inactive list, similar to the
* per zone LRU lists.
@@ -448,11 +449,14 @@ static inline void memcg_dangling_free(struct mem_cgroup *memcg) {}
static inline void memcg_dangling_add(struct mem_cgroup *memcg) {}
#endif
+static DEFINE_MUTEX(set_limit_mutex);
+
/* internal only representation about the status of kmem accounting. */
enum {
KMEM_ACCOUNTED_ACTIVE = 0, /* accounted by this cgroup itself */
KMEM_ACCOUNTED_ACTIVATED, /* static key enabled. */
KMEM_ACCOUNTED_DEAD, /* dead memcg with pending kmem charges */
+ KMEM_MAY_SHRINK, /* kmem limit < mem limit, shrink kmem only */
};
/* We account when limit is on, but only after call sites are patched */
@@ -491,6 +495,31 @@ static bool memcg_kmem_test_and_clear_dead(struct mem_cgroup *memcg)
return test_and_clear_bit(KMEM_ACCOUNTED_DEAD,
&memcg->kmem_account_flags);
}
+
+/*
+ * If the kernel limit is smaller than the user limit, we will have situations
+ * in which our allocations fail but freeing user pages will buy us nothing.
+ * In those, we would like to call a specialized memcg reclaimer that only
+ * frees kernel memory and leave the user memory alone.
+ *
+ * This test exists so we can differentiate between those. Everytime one of the
+ * limits is updated, we need to run it. The set_limit_mutex must be held, so
+ * they don't change again.
+ */
+static void memcg_update_shrink_status(struct mem_cgroup *memcg)
+{
+ mutex_lock(&set_limit_mutex);
+ if (res_counter_read_u64(&memcg->kmem, RES_LIMIT) <
+ res_counter_read_u64(&memcg->res, RES_LIMIT))
+ set_bit(KMEM_MAY_SHRINK, &memcg->kmem_account_flags);
+ else
+ clear_bit(KMEM_MAY_SHRINK, &memcg->kmem_account_flags);
+ mutex_unlock(&set_limit_mutex);
+}
+#else
+static void memcg_update_shrink_status(struct mem_cgroup *memcg)
+{
+}
#endif
/* Stuffs for move charges at task migration. */
@@ -3013,8 +3042,6 @@ static void __mem_cgroup_commit_charge(struct mem_cgroup *memcg,
memcg_check_events(memcg, page);
}
-static DEFINE_MUTEX(set_limit_mutex);
-
#ifdef CONFIG_MEMCG_KMEM
static inline bool memcg_can_account_kmem(struct mem_cgroup *memcg)
{
@@ -3056,16 +3083,91 @@ static int mem_cgroup_slabinfo_read(struct cgroup *cont, struct cftype *cft,
}
#endif
+/*
+ * During the creation a new cache, we need to disable our accounting mechanism
+ * altogether. This is true even if we are not creating, but rather just
+ * enqueing new caches to be created.
+ *
+ * This is because that process will trigger allocations; some visible, like
+ * explicit kmallocs to auxiliary data structures, name strings and internal
+ * cache structures; some well concealed, like INIT_WORK() that can allocate
+ * objects during debug.
+ *
+ * If any allocation happens during memcg_kmem_get_cache, we will recurse back
+ * to it. This may not be a bounded recursion: since the first cache creation
+ * failed to complete (waiting on the allocation), we'll just try to create the
+ * cache again, failing at the same point.
+ *
+ * memcg_kmem_get_cache is prepared to abort after seeing a positive count of
+ * memcg_kmem_skip_account. So we enclose anything that might allocate memory
+ * inside the following two functions.
+ */
+static inline void memcg_stop_kmem_account(void)
+{
+ VM_BUG_ON(!current->mm);
+ current->memcg_kmem_skip_account++;
+}
+
+static inline void memcg_resume_kmem_account(void)
+{
+ VM_BUG_ON(!current->mm);
+ current->memcg_kmem_skip_account--;
+}
+
+static int memcg_try_charge_kmem(struct mem_cgroup *memcg, gfp_t gfp, u64 size)
+{
+ int retries = MEM_CGROUP_RECLAIM_RETRIES;
+ struct res_counter *fail_res;
+ int ret;
+
+ do {
+ ret = res_counter_charge(&memcg->kmem, size, &fail_res);
+ if (!ret)
+ return ret;
+
+ if (!(gfp & __GFP_WAIT))
+ return ret;
+
+ /*
+ * We will try to shrink kernel memory present in caches. We
+ * are sure that we can wait, so we will. The duration of our
+ * wait is determined by congestion, the same way as vmscan.c
+ *
+ * If we are in FS context, though, then although we can wait,
+ * we cannot call the shrinkers. Most fs shrinkers (which
+ * comprises most of our kmem data) will not run without
+ * __GFP_FS since they can deadlock. The solution is to
+ * synchronously run that in a different context.
+ */
+ if (!(gfp & __GFP_FS)) {
+ /*
+ * we are already short on memory, every queue
+ * allocation is likely to fail
+ */
+ memcg_stop_kmem_account();
+ schedule_work(&memcg->kmemcg_shrink_work);
+ flush_work(&memcg->kmemcg_shrink_work);
+ memcg_resume_kmem_account();
+ } else
+ try_to_free_mem_cgroup_kmem(memcg, gfp);
+ } while (retries--);
+
+ return ret;
+}
+
static int memcg_charge_kmem(struct mem_cgroup *memcg, gfp_t gfp, u64 size)
{
struct res_counter *fail_res;
struct mem_cgroup *_memcg;
int ret = 0;
bool may_oom;
+ bool kmem_first = test_bit(KMEM_MAY_SHRINK, &memcg->kmem_account_flags);
- ret = res_counter_charge(&memcg->kmem, size, &fail_res);
- if (ret)
- return ret;
+ if (kmem_first) {
+ ret = memcg_try_charge_kmem(memcg, gfp, size);
+ if (ret)
+ return ret;
+ }
/*
* Conditions under which we can wait for the oom_killer. Those are
@@ -3098,12 +3200,41 @@ static int memcg_charge_kmem(struct mem_cgroup *memcg, gfp_t gfp, u64 size)
res_counter_charge_nofail(&memcg->memsw, size,
&fail_res);
ret = 0;
- } else if (ret)
+ if (kmem_first)
+ res_counter_charge_nofail(&memcg->kmem, size, &fail_res);
+ } else if (ret && kmem_first)
res_counter_uncharge(&memcg->kmem, size);
+ if (!ret && !kmem_first) {
+ ret = res_counter_charge(&memcg->kmem, size, &fail_res);
+ if (!ret)
+ return ret;
+
+ res_counter_uncharge(&memcg->res, size);
+ if (do_swap_account)
+ res_counter_uncharge(&memcg->memsw, size);
+ }
+
return ret;
}
+/*
+ * There might be situations in which there are plenty of objects to shrink,
+ * but we can't do it because the __GFP_FS flag is not set. This is the case
+ * with almost all inode allocation. They do are, however, capable of waiting.
+ * So we can just span a worker, let it finish its job and proceed with the
+ * allocation. As slow as it is, at this point we are already past any hopes
+ * anyway.
+ */
+static void kmemcg_shrink_work_fn(struct work_struct *w)
+{
+ struct mem_cgroup *memcg;
+
+ memcg = container_of(w, struct mem_cgroup, kmemcg_shrink_work);
+ try_to_free_mem_cgroup_kmem(memcg, GFP_KERNEL);
+}
+
+
static void memcg_uncharge_kmem(struct mem_cgroup *memcg, u64 size)
{
res_counter_uncharge(&memcg->res, size);
@@ -3180,6 +3311,7 @@ int memcg_update_cache_sizes(struct mem_cgroup *memcg)
memcg_update_array_size(num + 1);
INIT_LIST_HEAD(&memcg->memcg_slab_caches);
+ INIT_WORK(&memcg->kmemcg_shrink_work, kmemcg_shrink_work_fn);
mutex_init(&memcg->slab_caches_mutex);
return 0;
@@ -3456,37 +3588,6 @@ out:
kfree(s->memcg_params);
}
-/*
- * During the creation a new cache, we need to disable our accounting mechanism
- * altogether. This is true even if we are not creating, but rather just
- * enqueing new caches to be created.
- *
- * This is because that process will trigger allocations; some visible, like
- * explicit kmallocs to auxiliary data structures, name strings and internal
- * cache structures; some well concealed, like INIT_WORK() that can allocate
- * objects during debug.
- *
- * If any allocation happens during memcg_kmem_get_cache, we will recurse back
- * to it. This may not be a bounded recursion: since the first cache creation
- * failed to complete (waiting on the allocation), we'll just try to create the
- * cache again, failing at the same point.
- *
- * memcg_kmem_get_cache is prepared to abort after seeing a positive count of
- * memcg_kmem_skip_account. So we enclose anything that might allocate memory
- * inside the following two functions.
- */
-static inline void memcg_stop_kmem_account(void)
-{
- VM_BUG_ON(!current->mm);
- current->memcg_kmem_skip_account++;
-}
-
-static inline void memcg_resume_kmem_account(void)
-{
- VM_BUG_ON(!current->mm);
- current->memcg_kmem_skip_account--;
-}
-
struct mem_cgroup *mem_cgroup_from_kmem_page(struct page *page)
{
struct page_cgroup *pc;
@@ -5571,6 +5672,9 @@ static int mem_cgroup_write(struct cgroup *cont, struct cftype *cft,
ret = memcg_update_kmem_limit(cont, val);
else
return -EINVAL;
+
+ if (!ret)
+ memcg_update_shrink_status(memcg);
break;
case RES_SOFT_LIMIT:
ret = res_counter_memparse_write_strategy(buffer, &val);
diff --git a/mm/vmscan.c b/mm/vmscan.c
index eb5e67c..731e798 100644
--- a/mm/vmscan.c
+++ b/mm/vmscan.c
@@ -2513,7 +2513,49 @@ unsigned long try_to_free_mem_cgroup_pages(struct mem_cgroup *memcg,
return nr_reclaimed;
}
-#endif
+
+#ifdef CONFIG_MEMCG_KMEM
+/*
+ * This function is called when we are under kmem-specific pressure. It will
+ * only trigger in environments with kmem.limit_in_bytes < limit_in_bytes, IOW,
+ * with a lower kmem allowance than the memory allowance.
+ *
+ * In this situation, freeing user pages from the cgroup won't do us any good.
+ * What we really need is to call the memcg-aware shrinkers, in the hope of
+ * freeing pages holding kmem objects. It may also be that we won't be able to
+ * free any pages, but will get rid of old objects opening up space for new
+ * ones.
+ */
+unsigned long try_to_free_mem_cgroup_kmem(struct mem_cgroup *memcg,
+ gfp_t gfp_mask)
+{
+ long freed;
+
+ struct shrink_control shrink = {
+ .gfp_mask = gfp_mask,
+ .target_mem_cgroup = memcg,
+ };
+
+ if (!(gfp_mask & __GFP_WAIT))
+ return 0;
+
+ /*
+ * memcg pressure is always global */
+ nodes_setall(shrink.nodes_to_scan);
+
+ /*
+ * We haven't scanned any user LRU, so we basically come up with
+ * crafted values of nr_scanned and LRU page (1 and 0 respectively).
+ * This should be enough to tell shrink_slab that the freeing
+ * responsibility is all on himself.
+ */
+ freed = shrink_slab(&shrink, 1, 0);
+ if (!freed)
+ congestion_wait(BLK_RW_ASYNC, HZ/10);
+ return freed;
+}
+#endif /* CONFIG_MEMCG_KMEM */
+#endif /* CONFIG_MEMCG */
static void age_active_anon(struct zone *zone, struct scan_control *sc)
{
--
1.8.1.4
^ permalink raw reply related [flat|nested] 151+ messages in thread* [PATCH v6 25/31] memcg: per-memcg kmem shrinking
@ 2013-05-12 18:13 ` Glauber Costa
0 siblings, 0 replies; 151+ messages in thread
From: Glauber Costa @ 2013-05-12 18:13 UTC (permalink / raw)
To: linux-mm
Cc: cgroups, Andrew Morton, Greg Thelen, kamezawa.hiroyu,
Michal Hocko, Johannes Weiner, linux-fsdevel, Dave Chinner,
Glauber Costa, Dave Chinner, Mel Gorman, Rik van Riel,
Hugh Dickins
If the kernel limit is smaller than the user limit, we will have
situations in which our allocations fail but freeing user pages will buy
us nothing. In those, we would like to call a specialized memcg
reclaimer that only frees kernel memory and leave the user memory alone.
Those are also expected to fail when we account memcg->kmem, instead of
when we account memcg->res. Based on that, this patch implements a
memcg-specific reclaimer, that only shrinks kernel objects, withouth
touching user pages.
There might be situations in which there are plenty of objects to
shrink, but we can't do it because the __GFP_FS flag is not set.
Although they can happen with user pages, they are a lot more common
with fs-metadata: this is the case with almost all inode allocation.
Those allocations are, however, capable of waiting. So we can just span
a worker, let it finish its job and proceed with the allocation. As slow
as it is, at this point we are already past any hopes anyway.
[ v2: moved congestion_wait call to vmscan.c ]
Signed-off-by: Glauber Costa <glommer@openvz.org>
Cc: Dave Chinner <dchinner@redhat.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Rik van Riel <riel@redhat.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Michal Hocko <mhocko@suse.cz>
Cc: Hugh Dickins <hughd@google.com>
Cc: Kamezawa Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
---
include/linux/swap.h | 2 +
mm/memcontrol.c | 180 ++++++++++++++++++++++++++++++++++++++++-----------
mm/vmscan.c | 44 ++++++++++++-
3 files changed, 187 insertions(+), 39 deletions(-)
diff --git a/include/linux/swap.h b/include/linux/swap.h
index ca031f7..5a0ef45 100644
--- a/include/linux/swap.h
+++ b/include/linux/swap.h
@@ -268,6 +268,8 @@ extern unsigned long try_to_free_pages(struct zonelist *zonelist, int order,
extern int __isolate_lru_page(struct page *page, isolate_mode_t mode);
extern unsigned long try_to_free_mem_cgroup_pages(struct mem_cgroup *mem,
gfp_t gfp_mask, bool noswap);
+extern unsigned long try_to_free_mem_cgroup_kmem(struct mem_cgroup *mem,
+ gfp_t gfp_mask);
extern unsigned long mem_cgroup_shrink_node_zone(struct mem_cgroup *mem,
gfp_t gfp_mask, bool noswap,
struct zone *zone,
diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index 4bf6738..c563550 100644
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -382,7 +382,8 @@ struct mem_cgroup {
atomic_t numainfo_events;
atomic_t numainfo_updating;
#endif
-
+ /* when kmem shrinkers can sleep but can't proceed due to context */
+ struct work_struct kmemcg_shrink_work;
/*
* Per cgroup active and inactive list, similar to the
* per zone LRU lists.
@@ -448,11 +449,14 @@ static inline void memcg_dangling_free(struct mem_cgroup *memcg) {}
static inline void memcg_dangling_add(struct mem_cgroup *memcg) {}
#endif
+static DEFINE_MUTEX(set_limit_mutex);
+
/* internal only representation about the status of kmem accounting. */
enum {
KMEM_ACCOUNTED_ACTIVE = 0, /* accounted by this cgroup itself */
KMEM_ACCOUNTED_ACTIVATED, /* static key enabled. */
KMEM_ACCOUNTED_DEAD, /* dead memcg with pending kmem charges */
+ KMEM_MAY_SHRINK, /* kmem limit < mem limit, shrink kmem only */
};
/* We account when limit is on, but only after call sites are patched */
@@ -491,6 +495,31 @@ static bool memcg_kmem_test_and_clear_dead(struct mem_cgroup *memcg)
return test_and_clear_bit(KMEM_ACCOUNTED_DEAD,
&memcg->kmem_account_flags);
}
+
+/*
+ * If the kernel limit is smaller than the user limit, we will have situations
+ * in which our allocations fail but freeing user pages will buy us nothing.
+ * In those, we would like to call a specialized memcg reclaimer that only
+ * frees kernel memory and leave the user memory alone.
+ *
+ * This test exists so we can differentiate between those. Everytime one of the
+ * limits is updated, we need to run it. The set_limit_mutex must be held, so
+ * they don't change again.
+ */
+static void memcg_update_shrink_status(struct mem_cgroup *memcg)
+{
+ mutex_lock(&set_limit_mutex);
+ if (res_counter_read_u64(&memcg->kmem, RES_LIMIT) <
+ res_counter_read_u64(&memcg->res, RES_LIMIT))
+ set_bit(KMEM_MAY_SHRINK, &memcg->kmem_account_flags);
+ else
+ clear_bit(KMEM_MAY_SHRINK, &memcg->kmem_account_flags);
+ mutex_unlock(&set_limit_mutex);
+}
+#else
+static void memcg_update_shrink_status(struct mem_cgroup *memcg)
+{
+}
#endif
/* Stuffs for move charges at task migration. */
@@ -3013,8 +3042,6 @@ static void __mem_cgroup_commit_charge(struct mem_cgroup *memcg,
memcg_check_events(memcg, page);
}
-static DEFINE_MUTEX(set_limit_mutex);
-
#ifdef CONFIG_MEMCG_KMEM
static inline bool memcg_can_account_kmem(struct mem_cgroup *memcg)
{
@@ -3056,16 +3083,91 @@ static int mem_cgroup_slabinfo_read(struct cgroup *cont, struct cftype *cft,
}
#endif
+/*
+ * During the creation a new cache, we need to disable our accounting mechanism
+ * altogether. This is true even if we are not creating, but rather just
+ * enqueing new caches to be created.
+ *
+ * This is because that process will trigger allocations; some visible, like
+ * explicit kmallocs to auxiliary data structures, name strings and internal
+ * cache structures; some well concealed, like INIT_WORK() that can allocate
+ * objects during debug.
+ *
+ * If any allocation happens during memcg_kmem_get_cache, we will recurse back
+ * to it. This may not be a bounded recursion: since the first cache creation
+ * failed to complete (waiting on the allocation), we'll just try to create the
+ * cache again, failing at the same point.
+ *
+ * memcg_kmem_get_cache is prepared to abort after seeing a positive count of
+ * memcg_kmem_skip_account. So we enclose anything that might allocate memory
+ * inside the following two functions.
+ */
+static inline void memcg_stop_kmem_account(void)
+{
+ VM_BUG_ON(!current->mm);
+ current->memcg_kmem_skip_account++;
+}
+
+static inline void memcg_resume_kmem_account(void)
+{
+ VM_BUG_ON(!current->mm);
+ current->memcg_kmem_skip_account--;
+}
+
+static int memcg_try_charge_kmem(struct mem_cgroup *memcg, gfp_t gfp, u64 size)
+{
+ int retries = MEM_CGROUP_RECLAIM_RETRIES;
+ struct res_counter *fail_res;
+ int ret;
+
+ do {
+ ret = res_counter_charge(&memcg->kmem, size, &fail_res);
+ if (!ret)
+ return ret;
+
+ if (!(gfp & __GFP_WAIT))
+ return ret;
+
+ /*
+ * We will try to shrink kernel memory present in caches. We
+ * are sure that we can wait, so we will. The duration of our
+ * wait is determined by congestion, the same way as vmscan.c
+ *
+ * If we are in FS context, though, then although we can wait,
+ * we cannot call the shrinkers. Most fs shrinkers (which
+ * comprises most of our kmem data) will not run without
+ * __GFP_FS since they can deadlock. The solution is to
+ * synchronously run that in a different context.
+ */
+ if (!(gfp & __GFP_FS)) {
+ /*
+ * we are already short on memory, every queue
+ * allocation is likely to fail
+ */
+ memcg_stop_kmem_account();
+ schedule_work(&memcg->kmemcg_shrink_work);
+ flush_work(&memcg->kmemcg_shrink_work);
+ memcg_resume_kmem_account();
+ } else
+ try_to_free_mem_cgroup_kmem(memcg, gfp);
+ } while (retries--);
+
+ return ret;
+}
+
static int memcg_charge_kmem(struct mem_cgroup *memcg, gfp_t gfp, u64 size)
{
struct res_counter *fail_res;
struct mem_cgroup *_memcg;
int ret = 0;
bool may_oom;
+ bool kmem_first = test_bit(KMEM_MAY_SHRINK, &memcg->kmem_account_flags);
- ret = res_counter_charge(&memcg->kmem, size, &fail_res);
- if (ret)
- return ret;
+ if (kmem_first) {
+ ret = memcg_try_charge_kmem(memcg, gfp, size);
+ if (ret)
+ return ret;
+ }
/*
* Conditions under which we can wait for the oom_killer. Those are
@@ -3098,12 +3200,41 @@ static int memcg_charge_kmem(struct mem_cgroup *memcg, gfp_t gfp, u64 size)
res_counter_charge_nofail(&memcg->memsw, size,
&fail_res);
ret = 0;
- } else if (ret)
+ if (kmem_first)
+ res_counter_charge_nofail(&memcg->kmem, size, &fail_res);
+ } else if (ret && kmem_first)
res_counter_uncharge(&memcg->kmem, size);
+ if (!ret && !kmem_first) {
+ ret = res_counter_charge(&memcg->kmem, size, &fail_res);
+ if (!ret)
+ return ret;
+
+ res_counter_uncharge(&memcg->res, size);
+ if (do_swap_account)
+ res_counter_uncharge(&memcg->memsw, size);
+ }
+
return ret;
}
+/*
+ * There might be situations in which there are plenty of objects to shrink,
+ * but we can't do it because the __GFP_FS flag is not set. This is the case
+ * with almost all inode allocation. They do are, however, capable of waiting.
+ * So we can just span a worker, let it finish its job and proceed with the
+ * allocation. As slow as it is, at this point we are already past any hopes
+ * anyway.
+ */
+static void kmemcg_shrink_work_fn(struct work_struct *w)
+{
+ struct mem_cgroup *memcg;
+
+ memcg = container_of(w, struct mem_cgroup, kmemcg_shrink_work);
+ try_to_free_mem_cgroup_kmem(memcg, GFP_KERNEL);
+}
+
+
static void memcg_uncharge_kmem(struct mem_cgroup *memcg, u64 size)
{
res_counter_uncharge(&memcg->res, size);
@@ -3180,6 +3311,7 @@ int memcg_update_cache_sizes(struct mem_cgroup *memcg)
memcg_update_array_size(num + 1);
INIT_LIST_HEAD(&memcg->memcg_slab_caches);
+ INIT_WORK(&memcg->kmemcg_shrink_work, kmemcg_shrink_work_fn);
mutex_init(&memcg->slab_caches_mutex);
return 0;
@@ -3456,37 +3588,6 @@ out:
kfree(s->memcg_params);
}
-/*
- * During the creation a new cache, we need to disable our accounting mechanism
- * altogether. This is true even if we are not creating, but rather just
- * enqueing new caches to be created.
- *
- * This is because that process will trigger allocations; some visible, like
- * explicit kmallocs to auxiliary data structures, name strings and internal
- * cache structures; some well concealed, like INIT_WORK() that can allocate
- * objects during debug.
- *
- * If any allocation happens during memcg_kmem_get_cache, we will recurse back
- * to it. This may not be a bounded recursion: since the first cache creation
- * failed to complete (waiting on the allocation), we'll just try to create the
- * cache again, failing at the same point.
- *
- * memcg_kmem_get_cache is prepared to abort after seeing a positive count of
- * memcg_kmem_skip_account. So we enclose anything that might allocate memory
- * inside the following two functions.
- */
-static inline void memcg_stop_kmem_account(void)
-{
- VM_BUG_ON(!current->mm);
- current->memcg_kmem_skip_account++;
-}
-
-static inline void memcg_resume_kmem_account(void)
-{
- VM_BUG_ON(!current->mm);
- current->memcg_kmem_skip_account--;
-}
-
struct mem_cgroup *mem_cgroup_from_kmem_page(struct page *page)
{
struct page_cgroup *pc;
@@ -5571,6 +5672,9 @@ static int mem_cgroup_write(struct cgroup *cont, struct cftype *cft,
ret = memcg_update_kmem_limit(cont, val);
else
return -EINVAL;
+
+ if (!ret)
+ memcg_update_shrink_status(memcg);
break;
case RES_SOFT_LIMIT:
ret = res_counter_memparse_write_strategy(buffer, &val);
diff --git a/mm/vmscan.c b/mm/vmscan.c
index eb5e67c..731e798 100644
--- a/mm/vmscan.c
+++ b/mm/vmscan.c
@@ -2513,7 +2513,49 @@ unsigned long try_to_free_mem_cgroup_pages(struct mem_cgroup *memcg,
return nr_reclaimed;
}
-#endif
+
+#ifdef CONFIG_MEMCG_KMEM
+/*
+ * This function is called when we are under kmem-specific pressure. It will
+ * only trigger in environments with kmem.limit_in_bytes < limit_in_bytes, IOW,
+ * with a lower kmem allowance than the memory allowance.
+ *
+ * In this situation, freeing user pages from the cgroup won't do us any good.
+ * What we really need is to call the memcg-aware shrinkers, in the hope of
+ * freeing pages holding kmem objects. It may also be that we won't be able to
+ * free any pages, but will get rid of old objects opening up space for new
+ * ones.
+ */
+unsigned long try_to_free_mem_cgroup_kmem(struct mem_cgroup *memcg,
+ gfp_t gfp_mask)
+{
+ long freed;
+
+ struct shrink_control shrink = {
+ .gfp_mask = gfp_mask,
+ .target_mem_cgroup = memcg,
+ };
+
+ if (!(gfp_mask & __GFP_WAIT))
+ return 0;
+
+ /*
+ * memcg pressure is always global */
+ nodes_setall(shrink.nodes_to_scan);
+
+ /*
+ * We haven't scanned any user LRU, so we basically come up with
+ * crafted values of nr_scanned and LRU page (1 and 0 respectively).
+ * This should be enough to tell shrink_slab that the freeing
+ * responsibility is all on himself.
+ */
+ freed = shrink_slab(&shrink, 1, 0);
+ if (!freed)
+ congestion_wait(BLK_RW_ASYNC, HZ/10);
+ return freed;
+}
+#endif /* CONFIG_MEMCG_KMEM */
+#endif /* CONFIG_MEMCG */
static void age_active_anon(struct zone *zone, struct scan_control *sc)
{
--
1.8.1.4
--
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^ permalink raw reply related [flat|nested] 151+ messages in thread
* [PATCH v6 26/31] memcg: scan cache objects hierarchically
2013-05-12 18:13 ` Glauber Costa
(?)
@ 2013-05-12 18:13 ` Glauber Costa
-1 siblings, 0 replies; 151+ messages in thread
From: Glauber Costa @ 2013-05-12 18:13 UTC (permalink / raw)
To: linux-mm
Cc: cgroups, Andrew Morton, Greg Thelen, kamezawa.hiroyu,
Michal Hocko, Johannes Weiner, linux-fsdevel, Dave Chinner,
Glauber Costa, Dave Chinner, Mel Gorman, Rik van Riel,
Hugh Dickins
When reaching shrink_slab, we should descent in children memcg searching
for objects that could be shrunk. This is true even if the memcg does
not have kmem limits on, since the kmem res_counter will also be billed
against the user res_counter of the parent.
It is possible that we will free objects and not free any pages, that
will just harm the child groups without helping the parent group at all.
But at this point, we basically are prepared to pay the price.
Signed-off-by: Glauber Costa <glommer@openvz.org>
Cc: Dave Chinner <dchinner@redhat.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Rik van Riel <riel@redhat.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Michal Hocko <mhocko@suse.cz>
Cc: Hugh Dickins <hughd@google.com>
Cc: Kamezawa Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
---
include/linux/memcontrol.h | 6 ++
mm/memcontrol.c | 13 +++
mm/vmscan.c | 206 ++++++++++++++++++++++++++-------------------
3 files changed, 139 insertions(+), 86 deletions(-)
diff --git a/include/linux/memcontrol.h b/include/linux/memcontrol.h
index 3eeece8..c8b1412 100644
--- a/include/linux/memcontrol.h
+++ b/include/linux/memcontrol.h
@@ -441,6 +441,7 @@ static inline bool memcg_kmem_enabled(void)
return static_key_false(&memcg_kmem_enabled_key);
}
+bool memcg_kmem_should_reclaim(struct mem_cgroup *memcg);
bool memcg_kmem_is_active(struct mem_cgroup *memcg);
/*
@@ -585,6 +586,11 @@ memcg_kmem_get_cache(struct kmem_cache *cachep, gfp_t gfp)
}
#else
+static inline bool memcg_kmem_should_reclaim(struct mem_cgroup *memcg)
+{
+ return false;
+}
+
static inline bool memcg_kmem_is_active(struct mem_cgroup *memcg)
{
return false;
diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index c563550..b8980d1 100644
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -3043,6 +3043,19 @@ static void __mem_cgroup_commit_charge(struct mem_cgroup *memcg,
}
#ifdef CONFIG_MEMCG_KMEM
+bool memcg_kmem_should_reclaim(struct mem_cgroup *memcg)
+{
+ struct mem_cgroup *iter;
+
+ for_each_mem_cgroup_tree(iter, memcg) {
+ if (memcg_kmem_is_active(iter)) {
+ mem_cgroup_iter_break(memcg, iter);
+ return true;
+ }
+ }
+ return false;
+}
+
static inline bool memcg_can_account_kmem(struct mem_cgroup *memcg)
{
return !mem_cgroup_disabled() && !mem_cgroup_is_root(memcg) &&
diff --git a/mm/vmscan.c b/mm/vmscan.c
index 731e798..9c45e5c 100644
--- a/mm/vmscan.c
+++ b/mm/vmscan.c
@@ -148,7 +148,7 @@ static bool global_reclaim(struct scan_control *sc)
static bool has_kmem_reclaim(struct scan_control *sc)
{
return !sc->target_mem_cgroup ||
- memcg_kmem_is_active(sc->target_mem_cgroup);
+ memcg_kmem_should_reclaim(sc->target_mem_cgroup);
}
static unsigned long
@@ -209,6 +209,101 @@ void unregister_shrinker(struct shrinker *shrinker)
EXPORT_SYMBOL(unregister_shrinker);
#define SHRINK_BATCH 128
+unsigned long
+shrink_slab_one(struct shrinker *shrinker, struct shrink_control *shrinkctl,
+ unsigned long nr_pages_scanned, unsigned long lru_pages)
+{
+ unsigned long freed = 0;
+ unsigned long long delta;
+ long total_scan;
+ long max_pass;
+ long nr;
+ long new_nr;
+ long batch_size = shrinker->batch ? shrinker->batch
+ : SHRINK_BATCH;
+
+ max_pass = shrinker->count_objects(shrinker, shrinkctl);
+ WARN_ON(max_pass < 0);
+ if (max_pass <= 0)
+ return 0;
+
+ /*
+ * copy the current shrinker scan count into a local variable
+ * and zero it so that other concurrent shrinker invocations
+ * don't also do this scanning work.
+ */
+ nr = atomic_long_xchg(&shrinker->nr_in_batch, 0);
+
+ total_scan = nr;
+ delta = (4 * nr_pages_scanned) / shrinker->seeks;
+ delta *= max_pass;
+ do_div(delta, lru_pages + 1);
+ total_scan += delta;
+ if (total_scan < 0) {
+ printk(KERN_ERR
+ "shrink_slab: %pF negative objects to delete nr=%ld\n",
+ shrinker->scan_objects, total_scan);
+ total_scan = max_pass;
+ }
+
+ /*
+ * We need to avoid excessive windup on filesystem shrinkers
+ * due to large numbers of GFP_NOFS allocations causing the
+ * shrinkers to return -1 all the time. This results in a large
+ * nr being built up so when a shrink that can do some work
+ * comes along it empties the entire cache due to nr >>>
+ * max_pass. This is bad for sustaining a working set in
+ * memory.
+ *
+ * Hence only allow the shrinker to scan the entire cache when
+ * a large delta change is calculated directly.
+ */
+ if (delta < max_pass / 4)
+ total_scan = min(total_scan, max_pass / 2);
+
+ /*
+ * Avoid risking looping forever due to too large nr value:
+ * never try to free more than twice the estimate number of
+ * freeable entries.
+ */
+ if (total_scan > max_pass * 2)
+ total_scan = max_pass * 2;
+
+ trace_mm_shrink_slab_start(shrinker, shrinkctl, nr,
+ nr_pages_scanned, lru_pages,
+ max_pass, delta, total_scan);
+
+ while (total_scan >= batch_size) {
+ long ret;
+
+ shrinkctl->nr_to_scan = batch_size;
+ ret = shrinker->scan_objects(shrinker, shrinkctl);
+ if (ret == -1)
+ break;
+ freed += ret;
+
+ count_vm_events(SLABS_SCANNED, batch_size);
+ total_scan -= batch_size;
+
+ cond_resched();
+ }
+
+ /*
+ * move the unused scan count back into the shrinker in a
+ * manner that handles concurrent updates. If we exhausted the
+ * scan, there is no need to do an update.
+ */
+ if (total_scan > 0)
+ new_nr = atomic_long_add_return(total_scan,
+ &shrinker->nr_in_batch);
+ else
+ new_nr = atomic_long_read(&shrinker->nr_in_batch);
+
+ trace_mm_shrink_slab_end(shrinker, freed, nr, new_nr);
+
+ return freed;
+}
+
/*
* Call the shrink functions to age shrinkable caches
*
@@ -234,6 +329,7 @@ unsigned long shrink_slab(struct shrink_control *shrinkctl,
{
struct shrinker *shrinker;
unsigned long freed = 0;
+ struct mem_cgroup *root = shrinkctl->target_mem_cgroup;
if (nr_pages_scanned == 0)
nr_pages_scanned = SWAP_CLUSTER_MAX;
@@ -245,101 +341,39 @@ unsigned long shrink_slab(struct shrink_control *shrinkctl,
}
list_for_each_entry(shrinker, &shrinker_list, list) {
- unsigned long long delta;
- long total_scan;
- long max_pass;
- long nr;
- long new_nr;
- long batch_size = shrinker->batch ? shrinker->batch
- : SHRINK_BATCH;
+ struct mem_cgroup *memcg;
/*
* If we don't have a target mem cgroup, we scan them all.
* Otherwise we will limit our scan to shrinkers marked as
* memcg aware
*/
- if (shrinkctl->target_mem_cgroup && !shrinker->memcg_shrinker)
- continue;
-
- max_pass = shrinker->count_objects(shrinker, shrinkctl);
- WARN_ON(max_pass < 0);
- if (max_pass <= 0)
+ if (root && !shrinker->memcg_shrinker)
continue;
- /*
- * copy the current shrinker scan count into a local variable
- * and zero it so that other concurrent shrinker invocations
- * don't also do this scanning work.
- */
- nr = atomic_long_xchg(&shrinker->nr_in_batch, 0);
-
- total_scan = nr;
- delta = (4 * nr_pages_scanned) / shrinker->seeks;
- delta *= max_pass;
- do_div(delta, lru_pages + 1);
- total_scan += delta;
- if (total_scan < 0) {
- printk(KERN_ERR
- "shrink_slab: %pF negative objects to delete nr=%ld\n",
- shrinker->scan_objects, total_scan);
- total_scan = max_pass;
- }
-
- /*
- * We need to avoid excessive windup on filesystem shrinkers
- * due to large numbers of GFP_NOFS allocations causing the
- * shrinkers to return -1 all the time. This results in a large
- * nr being built up so when a shrink that can do some work
- * comes along it empties the entire cache due to nr >>>
- * max_pass. This is bad for sustaining a working set in
- * memory.
- *
- * Hence only allow the shrinker to scan the entire cache when
- * a large delta change is calculated directly.
- */
- if (delta < max_pass / 4)
- total_scan = min(total_scan, max_pass / 2);
-
- /*
- * Avoid risking looping forever due to too large nr value:
- * never try to free more than twice the estimate number of
- * freeable entries.
- */
- if (total_scan > max_pass * 2)
- total_scan = max_pass * 2;
-
- trace_mm_shrink_slab_start(shrinker, shrinkctl, nr,
- nr_pages_scanned, lru_pages,
- max_pass, delta, total_scan);
-
- while (total_scan >= batch_size) {
- long ret;
-
- shrinkctl->nr_to_scan = batch_size;
- ret = shrinker->scan_objects(shrinker, shrinkctl);
-
- if (ret == -1)
- break;
- freed += ret;
-
- count_vm_events(SLABS_SCANNED, batch_size);
- total_scan -= batch_size;
-
- cond_resched();
- }
+ memcg = mem_cgroup_iter(root, NULL, NULL);
+ do {
+ /*
+ * In a hierarchical chain, it might be that not all
+ * memcgs are kmem active. kmemcg design mandates that
+ * when one memcg is active, its children will be
+ * active as well. But it is perfectly possible that
+ * its parent is not.
+ *
+ * We also need to make sure we scan at least once, for
+ * the global case. So if we don't have a target memcg
+ * (saved in root), we proceed normally and expect to
+ * break in the next round.
+ */
- /*
- * move the unused scan count back into the shrinker in a
- * manner that handles concurrent updates. If we exhausted the
- * scan, there is no need to do an update.
- */
- if (total_scan > 0)
- new_nr = atomic_long_add_return(total_scan,
- &shrinker->nr_in_batch);
- else
- new_nr = atomic_long_read(&shrinker->nr_in_batch);
+ if (!root || memcg_kmem_is_active(memcg))
+ freed += shrink_slab_one(shrinker, shrinkctl,
+ nr_pages_scanned, lru_pages);
+ memcg = mem_cgroup_iter(root, memcg, NULL);
+ } while (memcg);
- trace_mm_shrink_slab_end(shrinker, freed, nr, new_nr);
+ /* restore original state */
+ shrinkctl->target_mem_cgroup = root;
}
up_read(&shrinker_rwsem);
out:
--
1.8.1.4
^ permalink raw reply related [flat|nested] 151+ messages in thread* [PATCH v6 26/31] memcg: scan cache objects hierarchically
@ 2013-05-12 18:13 ` Glauber Costa
0 siblings, 0 replies; 151+ messages in thread
From: Glauber Costa @ 2013-05-12 18:13 UTC (permalink / raw)
To: linux-mm
Cc: cgroups, Andrew Morton, Greg Thelen, kamezawa.hiroyu,
Michal Hocko, Johannes Weiner, linux-fsdevel, Dave Chinner,
Glauber Costa, Dave Chinner, Mel Gorman, Rik van Riel,
Hugh Dickins
When reaching shrink_slab, we should descent in children memcg searching
for objects that could be shrunk. This is true even if the memcg does
not have kmem limits on, since the kmem res_counter will also be billed
against the user res_counter of the parent.
It is possible that we will free objects and not free any pages, that
will just harm the child groups without helping the parent group at all.
But at this point, we basically are prepared to pay the price.
Signed-off-by: Glauber Costa <glommer@openvz.org>
Cc: Dave Chinner <dchinner@redhat.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Rik van Riel <riel@redhat.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Michal Hocko <mhocko@suse.cz>
Cc: Hugh Dickins <hughd@google.com>
Cc: Kamezawa Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
---
include/linux/memcontrol.h | 6 ++
mm/memcontrol.c | 13 +++
mm/vmscan.c | 206 ++++++++++++++++++++++++++-------------------
3 files changed, 139 insertions(+), 86 deletions(-)
diff --git a/include/linux/memcontrol.h b/include/linux/memcontrol.h
index 3eeece8..c8b1412 100644
--- a/include/linux/memcontrol.h
+++ b/include/linux/memcontrol.h
@@ -441,6 +441,7 @@ static inline bool memcg_kmem_enabled(void)
return static_key_false(&memcg_kmem_enabled_key);
}
+bool memcg_kmem_should_reclaim(struct mem_cgroup *memcg);
bool memcg_kmem_is_active(struct mem_cgroup *memcg);
/*
@@ -585,6 +586,11 @@ memcg_kmem_get_cache(struct kmem_cache *cachep, gfp_t gfp)
}
#else
+static inline bool memcg_kmem_should_reclaim(struct mem_cgroup *memcg)
+{
+ return false;
+}
+
static inline bool memcg_kmem_is_active(struct mem_cgroup *memcg)
{
return false;
diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index c563550..b8980d1 100644
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -3043,6 +3043,19 @@ static void __mem_cgroup_commit_charge(struct mem_cgroup *memcg,
}
#ifdef CONFIG_MEMCG_KMEM
+bool memcg_kmem_should_reclaim(struct mem_cgroup *memcg)
+{
+ struct mem_cgroup *iter;
+
+ for_each_mem_cgroup_tree(iter, memcg) {
+ if (memcg_kmem_is_active(iter)) {
+ mem_cgroup_iter_break(memcg, iter);
+ return true;
+ }
+ }
+ return false;
+}
+
static inline bool memcg_can_account_kmem(struct mem_cgroup *memcg)
{
return !mem_cgroup_disabled() && !mem_cgroup_is_root(memcg) &&
diff --git a/mm/vmscan.c b/mm/vmscan.c
index 731e798..9c45e5c 100644
--- a/mm/vmscan.c
+++ b/mm/vmscan.c
@@ -148,7 +148,7 @@ static bool global_reclaim(struct scan_control *sc)
static bool has_kmem_reclaim(struct scan_control *sc)
{
return !sc->target_mem_cgroup ||
- memcg_kmem_is_active(sc->target_mem_cgroup);
+ memcg_kmem_should_reclaim(sc->target_mem_cgroup);
}
static unsigned long
@@ -209,6 +209,101 @@ void unregister_shrinker(struct shrinker *shrinker)
EXPORT_SYMBOL(unregister_shrinker);
#define SHRINK_BATCH 128
+unsigned long
+shrink_slab_one(struct shrinker *shrinker, struct shrink_control *shrinkctl,
+ unsigned long nr_pages_scanned, unsigned long lru_pages)
+{
+ unsigned long freed = 0;
+ unsigned long long delta;
+ long total_scan;
+ long max_pass;
+ long nr;
+ long new_nr;
+ long batch_size = shrinker->batch ? shrinker->batch
+ : SHRINK_BATCH;
+
+ max_pass = shrinker->count_objects(shrinker, shrinkctl);
+ WARN_ON(max_pass < 0);
+ if (max_pass <= 0)
+ return 0;
+
+ /*
+ * copy the current shrinker scan count into a local variable
+ * and zero it so that other concurrent shrinker invocations
+ * don't also do this scanning work.
+ */
+ nr = atomic_long_xchg(&shrinker->nr_in_batch, 0);
+
+ total_scan = nr;
+ delta = (4 * nr_pages_scanned) / shrinker->seeks;
+ delta *= max_pass;
+ do_div(delta, lru_pages + 1);
+ total_scan += delta;
+ if (total_scan < 0) {
+ printk(KERN_ERR
+ "shrink_slab: %pF negative objects to delete nr=%ld\n",
+ shrinker->scan_objects, total_scan);
+ total_scan = max_pass;
+ }
+
+ /*
+ * We need to avoid excessive windup on filesystem shrinkers
+ * due to large numbers of GFP_NOFS allocations causing the
+ * shrinkers to return -1 all the time. This results in a large
+ * nr being built up so when a shrink that can do some work
+ * comes along it empties the entire cache due to nr >>>
+ * max_pass. This is bad for sustaining a working set in
+ * memory.
+ *
+ * Hence only allow the shrinker to scan the entire cache when
+ * a large delta change is calculated directly.
+ */
+ if (delta < max_pass / 4)
+ total_scan = min(total_scan, max_pass / 2);
+
+ /*
+ * Avoid risking looping forever due to too large nr value:
+ * never try to free more than twice the estimate number of
+ * freeable entries.
+ */
+ if (total_scan > max_pass * 2)
+ total_scan = max_pass * 2;
+
+ trace_mm_shrink_slab_start(shrinker, shrinkctl, nr,
+ nr_pages_scanned, lru_pages,
+ max_pass, delta, total_scan);
+
+ while (total_scan >= batch_size) {
+ long ret;
+
+ shrinkctl->nr_to_scan = batch_size;
+ ret = shrinker->scan_objects(shrinker, shrinkctl);
+ if (ret == -1)
+ break;
+ freed += ret;
+
+ count_vm_events(SLABS_SCANNED, batch_size);
+ total_scan -= batch_size;
+
+ cond_resched();
+ }
+
+ /*
+ * move the unused scan count back into the shrinker in a
+ * manner that handles concurrent updates. If we exhausted the
+ * scan, there is no need to do an update.
+ */
+ if (total_scan > 0)
+ new_nr = atomic_long_add_return(total_scan,
+ &shrinker->nr_in_batch);
+ else
+ new_nr = atomic_long_read(&shrinker->nr_in_batch);
+
+ trace_mm_shrink_slab_end(shrinker, freed, nr, new_nr);
+
+ return freed;
+}
+
/*
* Call the shrink functions to age shrinkable caches
*
@@ -234,6 +329,7 @@ unsigned long shrink_slab(struct shrink_control *shrinkctl,
{
struct shrinker *shrinker;
unsigned long freed = 0;
+ struct mem_cgroup *root = shrinkctl->target_mem_cgroup;
if (nr_pages_scanned == 0)
nr_pages_scanned = SWAP_CLUSTER_MAX;
@@ -245,101 +341,39 @@ unsigned long shrink_slab(struct shrink_control *shrinkctl,
}
list_for_each_entry(shrinker, &shrinker_list, list) {
- unsigned long long delta;
- long total_scan;
- long max_pass;
- long nr;
- long new_nr;
- long batch_size = shrinker->batch ? shrinker->batch
- : SHRINK_BATCH;
+ struct mem_cgroup *memcg;
/*
* If we don't have a target mem cgroup, we scan them all.
* Otherwise we will limit our scan to shrinkers marked as
* memcg aware
*/
- if (shrinkctl->target_mem_cgroup && !shrinker->memcg_shrinker)
- continue;
-
- max_pass = shrinker->count_objects(shrinker, shrinkctl);
- WARN_ON(max_pass < 0);
- if (max_pass <= 0)
+ if (root && !shrinker->memcg_shrinker)
continue;
- /*
- * copy the current shrinker scan count into a local variable
- * and zero it so that other concurrent shrinker invocations
- * don't also do this scanning work.
- */
- nr = atomic_long_xchg(&shrinker->nr_in_batch, 0);
-
- total_scan = nr;
- delta = (4 * nr_pages_scanned) / shrinker->seeks;
- delta *= max_pass;
- do_div(delta, lru_pages + 1);
- total_scan += delta;
- if (total_scan < 0) {
- printk(KERN_ERR
- "shrink_slab: %pF negative objects to delete nr=%ld\n",
- shrinker->scan_objects, total_scan);
- total_scan = max_pass;
- }
-
- /*
- * We need to avoid excessive windup on filesystem shrinkers
- * due to large numbers of GFP_NOFS allocations causing the
- * shrinkers to return -1 all the time. This results in a large
- * nr being built up so when a shrink that can do some work
- * comes along it empties the entire cache due to nr >>>
- * max_pass. This is bad for sustaining a working set in
- * memory.
- *
- * Hence only allow the shrinker to scan the entire cache when
- * a large delta change is calculated directly.
- */
- if (delta < max_pass / 4)
- total_scan = min(total_scan, max_pass / 2);
-
- /*
- * Avoid risking looping forever due to too large nr value:
- * never try to free more than twice the estimate number of
- * freeable entries.
- */
- if (total_scan > max_pass * 2)
- total_scan = max_pass * 2;
-
- trace_mm_shrink_slab_start(shrinker, shrinkctl, nr,
- nr_pages_scanned, lru_pages,
- max_pass, delta, total_scan);
-
- while (total_scan >= batch_size) {
- long ret;
-
- shrinkctl->nr_to_scan = batch_size;
- ret = shrinker->scan_objects(shrinker, shrinkctl);
-
- if (ret == -1)
- break;
- freed += ret;
-
- count_vm_events(SLABS_SCANNED, batch_size);
- total_scan -= batch_size;
-
- cond_resched();
- }
+ memcg = mem_cgroup_iter(root, NULL, NULL);
+ do {
+ /*
+ * In a hierarchical chain, it might be that not all
+ * memcgs are kmem active. kmemcg design mandates that
+ * when one memcg is active, its children will be
+ * active as well. But it is perfectly possible that
+ * its parent is not.
+ *
+ * We also need to make sure we scan at least once, for
+ * the global case. So if we don't have a target memcg
+ * (saved in root), we proceed normally and expect to
+ * break in the next round.
+ */
- /*
- * move the unused scan count back into the shrinker in a
- * manner that handles concurrent updates. If we exhausted the
- * scan, there is no need to do an update.
- */
- if (total_scan > 0)
- new_nr = atomic_long_add_return(total_scan,
- &shrinker->nr_in_batch);
- else
- new_nr = atomic_long_read(&shrinker->nr_in_batch);
+ if (!root || memcg_kmem_is_active(memcg))
+ freed += shrink_slab_one(shrinker, shrinkctl,
+ nr_pages_scanned, lru_pages);
+ memcg = mem_cgroup_iter(root, memcg, NULL);
+ } while (memcg);
- trace_mm_shrink_slab_end(shrinker, freed, nr, new_nr);
+ /* restore original state */
+ shrinkctl->target_mem_cgroup = root;
}
up_read(&shrinker_rwsem);
out:
--
1.8.1.4
^ permalink raw reply related [flat|nested] 151+ messages in thread* [PATCH v6 26/31] memcg: scan cache objects hierarchically
@ 2013-05-12 18:13 ` Glauber Costa
0 siblings, 0 replies; 151+ messages in thread
From: Glauber Costa @ 2013-05-12 18:13 UTC (permalink / raw)
To: linux-mm
Cc: cgroups, Andrew Morton, Greg Thelen, kamezawa.hiroyu,
Michal Hocko, Johannes Weiner, linux-fsdevel, Dave Chinner,
Glauber Costa, Dave Chinner, Mel Gorman, Rik van Riel,
Hugh Dickins
When reaching shrink_slab, we should descent in children memcg searching
for objects that could be shrunk. This is true even if the memcg does
not have kmem limits on, since the kmem res_counter will also be billed
against the user res_counter of the parent.
It is possible that we will free objects and not free any pages, that
will just harm the child groups without helping the parent group at all.
But at this point, we basically are prepared to pay the price.
Signed-off-by: Glauber Costa <glommer@openvz.org>
Cc: Dave Chinner <dchinner@redhat.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Rik van Riel <riel@redhat.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Michal Hocko <mhocko@suse.cz>
Cc: Hugh Dickins <hughd@google.com>
Cc: Kamezawa Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
---
include/linux/memcontrol.h | 6 ++
mm/memcontrol.c | 13 +++
mm/vmscan.c | 206 ++++++++++++++++++++++++++-------------------
3 files changed, 139 insertions(+), 86 deletions(-)
diff --git a/include/linux/memcontrol.h b/include/linux/memcontrol.h
index 3eeece8..c8b1412 100644
--- a/include/linux/memcontrol.h
+++ b/include/linux/memcontrol.h
@@ -441,6 +441,7 @@ static inline bool memcg_kmem_enabled(void)
return static_key_false(&memcg_kmem_enabled_key);
}
+bool memcg_kmem_should_reclaim(struct mem_cgroup *memcg);
bool memcg_kmem_is_active(struct mem_cgroup *memcg);
/*
@@ -585,6 +586,11 @@ memcg_kmem_get_cache(struct kmem_cache *cachep, gfp_t gfp)
}
#else
+static inline bool memcg_kmem_should_reclaim(struct mem_cgroup *memcg)
+{
+ return false;
+}
+
static inline bool memcg_kmem_is_active(struct mem_cgroup *memcg)
{
return false;
diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index c563550..b8980d1 100644
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -3043,6 +3043,19 @@ static void __mem_cgroup_commit_charge(struct mem_cgroup *memcg,
}
#ifdef CONFIG_MEMCG_KMEM
+bool memcg_kmem_should_reclaim(struct mem_cgroup *memcg)
+{
+ struct mem_cgroup *iter;
+
+ for_each_mem_cgroup_tree(iter, memcg) {
+ if (memcg_kmem_is_active(iter)) {
+ mem_cgroup_iter_break(memcg, iter);
+ return true;
+ }
+ }
+ return false;
+}
+
static inline bool memcg_can_account_kmem(struct mem_cgroup *memcg)
{
return !mem_cgroup_disabled() && !mem_cgroup_is_root(memcg) &&
diff --git a/mm/vmscan.c b/mm/vmscan.c
index 731e798..9c45e5c 100644
--- a/mm/vmscan.c
+++ b/mm/vmscan.c
@@ -148,7 +148,7 @@ static bool global_reclaim(struct scan_control *sc)
static bool has_kmem_reclaim(struct scan_control *sc)
{
return !sc->target_mem_cgroup ||
- memcg_kmem_is_active(sc->target_mem_cgroup);
+ memcg_kmem_should_reclaim(sc->target_mem_cgroup);
}
static unsigned long
@@ -209,6 +209,101 @@ void unregister_shrinker(struct shrinker *shrinker)
EXPORT_SYMBOL(unregister_shrinker);
#define SHRINK_BATCH 128
+unsigned long
+shrink_slab_one(struct shrinker *shrinker, struct shrink_control *shrinkctl,
+ unsigned long nr_pages_scanned, unsigned long lru_pages)
+{
+ unsigned long freed = 0;
+ unsigned long long delta;
+ long total_scan;
+ long max_pass;
+ long nr;
+ long new_nr;
+ long batch_size = shrinker->batch ? shrinker->batch
+ : SHRINK_BATCH;
+
+ max_pass = shrinker->count_objects(shrinker, shrinkctl);
+ WARN_ON(max_pass < 0);
+ if (max_pass <= 0)
+ return 0;
+
+ /*
+ * copy the current shrinker scan count into a local variable
+ * and zero it so that other concurrent shrinker invocations
+ * don't also do this scanning work.
+ */
+ nr = atomic_long_xchg(&shrinker->nr_in_batch, 0);
+
+ total_scan = nr;
+ delta = (4 * nr_pages_scanned) / shrinker->seeks;
+ delta *= max_pass;
+ do_div(delta, lru_pages + 1);
+ total_scan += delta;
+ if (total_scan < 0) {
+ printk(KERN_ERR
+ "shrink_slab: %pF negative objects to delete nr=%ld\n",
+ shrinker->scan_objects, total_scan);
+ total_scan = max_pass;
+ }
+
+ /*
+ * We need to avoid excessive windup on filesystem shrinkers
+ * due to large numbers of GFP_NOFS allocations causing the
+ * shrinkers to return -1 all the time. This results in a large
+ * nr being built up so when a shrink that can do some work
+ * comes along it empties the entire cache due to nr >>>
+ * max_pass. This is bad for sustaining a working set in
+ * memory.
+ *
+ * Hence only allow the shrinker to scan the entire cache when
+ * a large delta change is calculated directly.
+ */
+ if (delta < max_pass / 4)
+ total_scan = min(total_scan, max_pass / 2);
+
+ /*
+ * Avoid risking looping forever due to too large nr value:
+ * never try to free more than twice the estimate number of
+ * freeable entries.
+ */
+ if (total_scan > max_pass * 2)
+ total_scan = max_pass * 2;
+
+ trace_mm_shrink_slab_start(shrinker, shrinkctl, nr,
+ nr_pages_scanned, lru_pages,
+ max_pass, delta, total_scan);
+
+ while (total_scan >= batch_size) {
+ long ret;
+
+ shrinkctl->nr_to_scan = batch_size;
+ ret = shrinker->scan_objects(shrinker, shrinkctl);
+ if (ret == -1)
+ break;
+ freed += ret;
+
+ count_vm_events(SLABS_SCANNED, batch_size);
+ total_scan -= batch_size;
+
+ cond_resched();
+ }
+
+ /*
+ * move the unused scan count back into the shrinker in a
+ * manner that handles concurrent updates. If we exhausted the
+ * scan, there is no need to do an update.
+ */
+ if (total_scan > 0)
+ new_nr = atomic_long_add_return(total_scan,
+ &shrinker->nr_in_batch);
+ else
+ new_nr = atomic_long_read(&shrinker->nr_in_batch);
+
+ trace_mm_shrink_slab_end(shrinker, freed, nr, new_nr);
+
+ return freed;
+}
+
/*
* Call the shrink functions to age shrinkable caches
*
@@ -234,6 +329,7 @@ unsigned long shrink_slab(struct shrink_control *shrinkctl,
{
struct shrinker *shrinker;
unsigned long freed = 0;
+ struct mem_cgroup *root = shrinkctl->target_mem_cgroup;
if (nr_pages_scanned == 0)
nr_pages_scanned = SWAP_CLUSTER_MAX;
@@ -245,101 +341,39 @@ unsigned long shrink_slab(struct shrink_control *shrinkctl,
}
list_for_each_entry(shrinker, &shrinker_list, list) {
- unsigned long long delta;
- long total_scan;
- long max_pass;
- long nr;
- long new_nr;
- long batch_size = shrinker->batch ? shrinker->batch
- : SHRINK_BATCH;
+ struct mem_cgroup *memcg;
/*
* If we don't have a target mem cgroup, we scan them all.
* Otherwise we will limit our scan to shrinkers marked as
* memcg aware
*/
- if (shrinkctl->target_mem_cgroup && !shrinker->memcg_shrinker)
- continue;
-
- max_pass = shrinker->count_objects(shrinker, shrinkctl);
- WARN_ON(max_pass < 0);
- if (max_pass <= 0)
+ if (root && !shrinker->memcg_shrinker)
continue;
- /*
- * copy the current shrinker scan count into a local variable
- * and zero it so that other concurrent shrinker invocations
- * don't also do this scanning work.
- */
- nr = atomic_long_xchg(&shrinker->nr_in_batch, 0);
-
- total_scan = nr;
- delta = (4 * nr_pages_scanned) / shrinker->seeks;
- delta *= max_pass;
- do_div(delta, lru_pages + 1);
- total_scan += delta;
- if (total_scan < 0) {
- printk(KERN_ERR
- "shrink_slab: %pF negative objects to delete nr=%ld\n",
- shrinker->scan_objects, total_scan);
- total_scan = max_pass;
- }
-
- /*
- * We need to avoid excessive windup on filesystem shrinkers
- * due to large numbers of GFP_NOFS allocations causing the
- * shrinkers to return -1 all the time. This results in a large
- * nr being built up so when a shrink that can do some work
- * comes along it empties the entire cache due to nr >>>
- * max_pass. This is bad for sustaining a working set in
- * memory.
- *
- * Hence only allow the shrinker to scan the entire cache when
- * a large delta change is calculated directly.
- */
- if (delta < max_pass / 4)
- total_scan = min(total_scan, max_pass / 2);
-
- /*
- * Avoid risking looping forever due to too large nr value:
- * never try to free more than twice the estimate number of
- * freeable entries.
- */
- if (total_scan > max_pass * 2)
- total_scan = max_pass * 2;
-
- trace_mm_shrink_slab_start(shrinker, shrinkctl, nr,
- nr_pages_scanned, lru_pages,
- max_pass, delta, total_scan);
-
- while (total_scan >= batch_size) {
- long ret;
-
- shrinkctl->nr_to_scan = batch_size;
- ret = shrinker->scan_objects(shrinker, shrinkctl);
-
- if (ret == -1)
- break;
- freed += ret;
-
- count_vm_events(SLABS_SCANNED, batch_size);
- total_scan -= batch_size;
-
- cond_resched();
- }
+ memcg = mem_cgroup_iter(root, NULL, NULL);
+ do {
+ /*
+ * In a hierarchical chain, it might be that not all
+ * memcgs are kmem active. kmemcg design mandates that
+ * when one memcg is active, its children will be
+ * active as well. But it is perfectly possible that
+ * its parent is not.
+ *
+ * We also need to make sure we scan at least once, for
+ * the global case. So if we don't have a target memcg
+ * (saved in root), we proceed normally and expect to
+ * break in the next round.
+ */
- /*
- * move the unused scan count back into the shrinker in a
- * manner that handles concurrent updates. If we exhausted the
- * scan, there is no need to do an update.
- */
- if (total_scan > 0)
- new_nr = atomic_long_add_return(total_scan,
- &shrinker->nr_in_batch);
- else
- new_nr = atomic_long_read(&shrinker->nr_in_batch);
+ if (!root || memcg_kmem_is_active(memcg))
+ freed += shrink_slab_one(shrinker, shrinkctl,
+ nr_pages_scanned, lru_pages);
+ memcg = mem_cgroup_iter(root, memcg, NULL);
+ } while (memcg);
- trace_mm_shrink_slab_end(shrinker, freed, nr, new_nr);
+ /* restore original state */
+ shrinkctl->target_mem_cgroup = root;
}
up_read(&shrinker_rwsem);
out:
--
1.8.1.4
--
To unsubscribe, send a message with 'unsubscribe linux-mm' in
the body to majordomo@kvack.org. For more info on Linux MM,
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^ permalink raw reply related [flat|nested] 151+ messages in thread
* [PATCH v6 27/31] vmscan: take at least one pass with shrinkers
2013-05-12 18:13 ` Glauber Costa
@ 2013-05-12 18:13 ` Glauber Costa
-1 siblings, 0 replies; 151+ messages in thread
From: Glauber Costa @ 2013-05-12 18:13 UTC (permalink / raw)
To: linux-mm
Cc: cgroups, Andrew Morton, Greg Thelen, kamezawa.hiroyu,
Michal Hocko, Johannes Weiner, linux-fsdevel, Dave Chinner,
Glauber Costa, Carlos Maiolino, Theodore Ts'o, Al Viro
In very low free kernel memory situations, it may be the case that we
have less objects to free than our initial batch size. If this is the
case, it is better to shrink those, and open space for the new workload
then to keep them and fail the new allocations.
In particular, we are concerned with the direct reclaim case for memcg.
Although this same technique can be applied to other situations just as well,
we will start conservative and apply it for that case, which is the one
that matters the most.
[ v6: only do it per memcg ]
[ v5: differentiate no-scan case, don't do this for kswapd ]
Signed-off-by: Glauber Costa <glommer@openvz.org>
CC: Dave Chinner <david@fromorbit.com>
CC: Carlos Maiolino <cmaiolino@redhat.com>
CC: "Theodore Ts'o" <tytso@mit.edu>
CC: Al Viro <viro@zeniv.linux.org.uk>
---
mm/vmscan.c | 23 ++++++++++++++++++-----
1 file changed, 18 insertions(+), 5 deletions(-)
diff --git a/mm/vmscan.c b/mm/vmscan.c
index 9c45e5c..6bac41e 100644
--- a/mm/vmscan.c
+++ b/mm/vmscan.c
@@ -273,20 +273,33 @@ shrink_slab_one(struct shrinker *shrinker, struct shrink_control *shrinkctl,
nr_pages_scanned, lru_pages,
max_pass, delta, total_scan);
- while (total_scan >= batch_size) {
+ do {
long ret;
+ unsigned long nr_to_scan = min(batch_size, total_scan);
+ struct mem_cgroup *memcg = shrinkctl->target_mem_cgroup;
+
+ /*
+ * Differentiate between "few objects" and "no objects"
+ * as returned by the count step.
+ */
+ if (!total_scan)
+ break;
+
+ if ((total_scan < batch_size) &&
+ !(memcg && memcg_kmem_is_active(memcg)))
+ break;
- shrinkctl->nr_to_scan = batch_size;
+ shrinkctl->nr_to_scan = nr_to_scan;
ret = shrinker->scan_objects(shrinker, shrinkctl);
if (ret == -1)
break;
freed += ret;
- count_vm_events(SLABS_SCANNED, batch_size);
- total_scan -= batch_size;
+ count_vm_events(SLABS_SCANNED, nr_to_scan);
+ total_scan -= nr_to_scan;
cond_resched();
- }
+ } while (total_scan >= batch_size);
/*
* move the unused scan count back into the shrinker in a
--
1.8.1.4
--
To unsubscribe, send a message with 'unsubscribe linux-mm' in
the body to majordomo@kvack.org. For more info on Linux MM,
see: http://www.linux-mm.org/ .
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^ permalink raw reply related [flat|nested] 151+ messages in thread* [PATCH v6 27/31] vmscan: take at least one pass with shrinkers
@ 2013-05-12 18:13 ` Glauber Costa
0 siblings, 0 replies; 151+ messages in thread
From: Glauber Costa @ 2013-05-12 18:13 UTC (permalink / raw)
To: linux-mm
Cc: cgroups, Andrew Morton, Greg Thelen, kamezawa.hiroyu,
Michal Hocko, Johannes Weiner, linux-fsdevel, Dave Chinner,
Glauber Costa, Carlos Maiolino, Theodore Ts'o, Al Viro
In very low free kernel memory situations, it may be the case that we
have less objects to free than our initial batch size. If this is the
case, it is better to shrink those, and open space for the new workload
then to keep them and fail the new allocations.
In particular, we are concerned with the direct reclaim case for memcg.
Although this same technique can be applied to other situations just as well,
we will start conservative and apply it for that case, which is the one
that matters the most.
[ v6: only do it per memcg ]
[ v5: differentiate no-scan case, don't do this for kswapd ]
Signed-off-by: Glauber Costa <glommer@openvz.org>
CC: Dave Chinner <david@fromorbit.com>
CC: Carlos Maiolino <cmaiolino@redhat.com>
CC: "Theodore Ts'o" <tytso@mit.edu>
CC: Al Viro <viro@zeniv.linux.org.uk>
---
mm/vmscan.c | 23 ++++++++++++++++++-----
1 file changed, 18 insertions(+), 5 deletions(-)
diff --git a/mm/vmscan.c b/mm/vmscan.c
index 9c45e5c..6bac41e 100644
--- a/mm/vmscan.c
+++ b/mm/vmscan.c
@@ -273,20 +273,33 @@ shrink_slab_one(struct shrinker *shrinker, struct shrink_control *shrinkctl,
nr_pages_scanned, lru_pages,
max_pass, delta, total_scan);
- while (total_scan >= batch_size) {
+ do {
long ret;
+ unsigned long nr_to_scan = min(batch_size, total_scan);
+ struct mem_cgroup *memcg = shrinkctl->target_mem_cgroup;
+
+ /*
+ * Differentiate between "few objects" and "no objects"
+ * as returned by the count step.
+ */
+ if (!total_scan)
+ break;
+
+ if ((total_scan < batch_size) &&
+ !(memcg && memcg_kmem_is_active(memcg)))
+ break;
- shrinkctl->nr_to_scan = batch_size;
+ shrinkctl->nr_to_scan = nr_to_scan;
ret = shrinker->scan_objects(shrinker, shrinkctl);
if (ret == -1)
break;
freed += ret;
- count_vm_events(SLABS_SCANNED, batch_size);
- total_scan -= batch_size;
+ count_vm_events(SLABS_SCANNED, nr_to_scan);
+ total_scan -= nr_to_scan;
cond_resched();
- }
+ } while (total_scan >= batch_size);
/*
* move the unused scan count back into the shrinker in a
--
1.8.1.4
--
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the body to majordomo@kvack.org. For more info on Linux MM,
see: http://www.linux-mm.org/ .
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^ permalink raw reply related [flat|nested] 151+ messages in thread
* [PATCH v6 28/31] super: targeted memcg reclaim
2013-05-12 18:13 ` Glauber Costa
(?)
@ 2013-05-12 18:13 ` Glauber Costa
-1 siblings, 0 replies; 151+ messages in thread
From: Glauber Costa @ 2013-05-12 18:13 UTC (permalink / raw)
To: linux-mm
Cc: cgroups, Andrew Morton, Greg Thelen, kamezawa.hiroyu,
Michal Hocko, Johannes Weiner, linux-fsdevel, Dave Chinner,
Glauber Costa, Dave Chinner, Mel Gorman, Rik van Riel,
Hugh Dickins
We now have all our dentries and inodes placed in memcg-specific LRU
lists. All we have to do is restrict the reclaim to the said lists in
case of memcg pressure.
That can't be done so easily for the fs_objects part of the equation,
since this is heavily fs-specific. What we do is pass on the context,
and let the filesystems decide if they ever chose or want to. At this
time, we just don't shrink them in memcg pressure (none is supported),
leaving that for global pressure only.
Marking the superblock shrinker and its LRUs as memcg-aware will
guarantee that the shrinkers will get invoked during targetted reclaim.
Signed-off-by: Glauber Costa <glommer@openvz.org>
Cc: Dave Chinner <dchinner@redhat.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Rik van Riel <riel@redhat.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Michal Hocko <mhocko@suse.cz>
Cc: Hugh Dickins <hughd@google.com>
Cc: Kamezawa Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
---
fs/dcache.c | 6 +++---
fs/inode.c | 6 +++---
fs/internal.h | 5 +++--
fs/super.c | 39 +++++++++++++++++++++++++++------------
4 files changed, 36 insertions(+), 20 deletions(-)
diff --git a/fs/dcache.c b/fs/dcache.c
index 20ab9c0..5eda937 100644
--- a/fs/dcache.c
+++ b/fs/dcache.c
@@ -885,13 +885,13 @@ dentry_lru_isolate(struct list_head *item, spinlock_t *lru_lock, void *arg)
* use.
*/
long prune_dcache_sb(struct super_block *sb, unsigned long nr_to_scan,
- nodemask_t *nodes_to_walk)
+ nodemask_t *nodes_to_walk, struct mem_cgroup *memcg)
{
LIST_HEAD(dispose);
long freed;
- freed = list_lru_walk_nodemask(&sb->s_dentry_lru, dentry_lru_isolate,
- &dispose, nr_to_scan, nodes_to_walk);
+ freed = list_lru_walk_nodemask_memcg(&sb->s_dentry_lru,
+ dentry_lru_isolate, &dispose, nr_to_scan, nodes_to_walk, memcg);
shrink_dentry_list(&dispose);
return freed;
}
diff --git a/fs/inode.c b/fs/inode.c
index 3cf4cb0..6565d88 100644
--- a/fs/inode.c
+++ b/fs/inode.c
@@ -747,13 +747,13 @@ inode_lru_isolate(struct list_head *item, spinlock_t *lru_lock, void *arg)
* then are freed outside inode_lock by dispose_list().
*/
long prune_icache_sb(struct super_block *sb, unsigned long nr_to_scan,
- nodemask_t *nodes_to_walk)
+ nodemask_t *nodes_to_walk, struct mem_cgroup *memcg)
{
LIST_HEAD(freeable);
long freed;
- freed = list_lru_walk_nodemask(&sb->s_inode_lru, inode_lru_isolate,
- &freeable, nr_to_scan, nodes_to_walk);
+ freed = list_lru_walk_nodemask_memcg(&sb->s_inode_lru,
+ inode_lru_isolate, &freeable, nr_to_scan, nodes_to_walk, memcg);
dispose_list(&freeable);
return freed;
}
diff --git a/fs/internal.h b/fs/internal.h
index 91900f2..068c7f7 100644
--- a/fs/internal.h
+++ b/fs/internal.h
@@ -16,6 +16,7 @@ struct file_system_type;
struct linux_binprm;
struct path;
struct mount;
+struct mem_cgroup;
/*
* block_dev.c
@@ -111,7 +112,7 @@ extern int open_check_o_direct(struct file *f);
*/
extern spinlock_t inode_sb_list_lock;
extern long prune_icache_sb(struct super_block *sb, unsigned long nr_to_scan,
- nodemask_t *nodes_to_scan);
+ nodemask_t *nodes_to_scan, struct mem_cgroup *memcg);
extern void inode_add_lru(struct inode *inode);
/*
@@ -128,7 +129,7 @@ extern int invalidate_inodes(struct super_block *, bool);
*/
extern struct dentry *__d_alloc(struct super_block *, const struct qstr *);
extern long prune_dcache_sb(struct super_block *sb, unsigned long nr_to_scan,
- nodemask_t *nodes_to_scan);
+ nodemask_t *nodes_to_scan, struct mem_cgroup *memcg);
/*
* read_write.c
diff --git a/fs/super.c b/fs/super.c
index 5c7b879..e92ebcb 100644
--- a/fs/super.c
+++ b/fs/super.c
@@ -34,6 +34,7 @@
#include <linux/cleancache.h>
#include <linux/fsnotify.h>
#include <linux/lockdep.h>
+#include <linux/memcontrol.h>
#include "internal.h"
@@ -56,6 +57,7 @@ static char *sb_writers_name[SB_FREEZE_LEVELS] = {
static long super_cache_scan(struct shrinker *shrink, struct shrink_control *sc)
{
struct super_block *sb;
+ struct mem_cgroup *memcg = sc->target_mem_cgroup;
long fs_objects = 0;
long total_objects;
long freed = 0;
@@ -74,11 +76,13 @@ static long super_cache_scan(struct shrinker *shrink, struct shrink_control *sc)
if (!grab_super_passive(sb))
return -1;
- if (sb->s_op && sb->s_op->nr_cached_objects)
+ if (sb->s_op && sb->s_op->nr_cached_objects && !memcg)
fs_objects = sb->s_op->nr_cached_objects(sb, &sc->nodes_to_scan);
- inodes = list_lru_count_nodemask(&sb->s_inode_lru, &sc->nodes_to_scan);
- dentries = list_lru_count_nodemask(&sb->s_dentry_lru, &sc->nodes_to_scan);
+ inodes = list_lru_count_nodemask_memcg(&sb->s_inode_lru,
+ &sc->nodes_to_scan, memcg);
+ dentries = list_lru_count_nodemask_memcg(&sb->s_dentry_lru,
+ &sc->nodes_to_scan, memcg);
total_objects = dentries + inodes + fs_objects + 1;
/* proportion the scan between the caches */
@@ -89,8 +93,8 @@ static long super_cache_scan(struct shrinker *shrink, struct shrink_control *sc)
* prune the dcache first as the icache is pinned by it, then
* prune the icache, followed by the filesystem specific caches
*/
- freed = prune_dcache_sb(sb, dentries, &sc->nodes_to_scan);
- freed += prune_icache_sb(sb, inodes, &sc->nodes_to_scan);
+ freed = prune_dcache_sb(sb, dentries, &sc->nodes_to_scan, memcg);
+ freed += prune_icache_sb(sb, inodes, &sc->nodes_to_scan, memcg);
if (fs_objects) {
fs_objects = mult_frac(sc->nr_to_scan, fs_objects,
@@ -107,20 +111,26 @@ static long super_cache_count(struct shrinker *shrink, struct shrink_control *sc
{
struct super_block *sb;
long total_objects = 0;
+ struct mem_cgroup *memcg = sc->target_mem_cgroup;
sb = container_of(shrink, struct super_block, s_shrink);
if (!grab_super_passive(sb))
return -1;
- if (sb->s_op && sb->s_op->nr_cached_objects)
+ /*
+ * Ideally we would pass memcg to nr_cached_objects, and
+ * let the underlying filesystem decide. Most likely the
+ * path will be if (!memcg) return;, but even then.
+ */
+ if (sb->s_op && sb->s_op->nr_cached_objects && !memcg)
total_objects = sb->s_op->nr_cached_objects(sb,
&sc->nodes_to_scan);
- total_objects += list_lru_count_nodemask(&sb->s_dentry_lru,
- &sc->nodes_to_scan);
- total_objects += list_lru_count_nodemask(&sb->s_inode_lru,
- &sc->nodes_to_scan);
+ total_objects += list_lru_count_nodemask_memcg(&sb->s_dentry_lru,
+ &sc->nodes_to_scan, memcg);
+ total_objects += list_lru_count_nodemask_memcg(&sb->s_inode_lru,
+ &sc->nodes_to_scan, memcg);
total_objects = vfs_pressure_ratio(total_objects);
drop_super(sb);
@@ -199,8 +209,10 @@ static struct super_block *alloc_super(struct file_system_type *type, int flags)
INIT_HLIST_NODE(&s->s_instances);
INIT_HLIST_BL_HEAD(&s->s_anon);
INIT_LIST_HEAD(&s->s_inodes);
- list_lru_init(&s->s_dentry_lru);
- list_lru_init(&s->s_inode_lru);
+
+ list_lru_init_memcg(&s->s_dentry_lru);
+ list_lru_init_memcg(&s->s_inode_lru);
+
INIT_LIST_HEAD(&s->s_mounts);
init_rwsem(&s->s_umount);
lockdep_set_class(&s->s_umount, &type->s_umount_key);
@@ -236,6 +248,7 @@ static struct super_block *alloc_super(struct file_system_type *type, int flags)
s->s_shrink.scan_objects = super_cache_scan;
s->s_shrink.count_objects = super_cache_count;
s->s_shrink.batch = 1024;
+ s->s_shrink.memcg_shrinker = true;
}
out:
return s;
@@ -318,6 +331,8 @@ void deactivate_locked_super(struct super_block *s)
/* caches are now gone, we can safely kill the shrinker now */
unregister_shrinker(&s->s_shrink);
+ list_lru_destroy(&s->s_dentry_lru);
+ list_lru_destroy(&s->s_inode_lru);
put_filesystem(fs);
put_super(s);
} else {
--
1.8.1.4
^ permalink raw reply related [flat|nested] 151+ messages in thread* [PATCH v6 28/31] super: targeted memcg reclaim
@ 2013-05-12 18:13 ` Glauber Costa
0 siblings, 0 replies; 151+ messages in thread
From: Glauber Costa @ 2013-05-12 18:13 UTC (permalink / raw)
To: linux-mm
Cc: cgroups, Andrew Morton, Greg Thelen, kamezawa.hiroyu,
Michal Hocko, Johannes Weiner, linux-fsdevel, Dave Chinner,
Glauber Costa, Dave Chinner, Mel Gorman, Rik van Riel,
Hugh Dickins
We now have all our dentries and inodes placed in memcg-specific LRU
lists. All we have to do is restrict the reclaim to the said lists in
case of memcg pressure.
That can't be done so easily for the fs_objects part of the equation,
since this is heavily fs-specific. What we do is pass on the context,
and let the filesystems decide if they ever chose or want to. At this
time, we just don't shrink them in memcg pressure (none is supported),
leaving that for global pressure only.
Marking the superblock shrinker and its LRUs as memcg-aware will
guarantee that the shrinkers will get invoked during targetted reclaim.
Signed-off-by: Glauber Costa <glommer@openvz.org>
Cc: Dave Chinner <dchinner@redhat.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Rik van Riel <riel@redhat.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Michal Hocko <mhocko@suse.cz>
Cc: Hugh Dickins <hughd@google.com>
Cc: Kamezawa Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
---
fs/dcache.c | 6 +++---
fs/inode.c | 6 +++---
fs/internal.h | 5 +++--
fs/super.c | 39 +++++++++++++++++++++++++++------------
4 files changed, 36 insertions(+), 20 deletions(-)
diff --git a/fs/dcache.c b/fs/dcache.c
index 20ab9c0..5eda937 100644
--- a/fs/dcache.c
+++ b/fs/dcache.c
@@ -885,13 +885,13 @@ dentry_lru_isolate(struct list_head *item, spinlock_t *lru_lock, void *arg)
* use.
*/
long prune_dcache_sb(struct super_block *sb, unsigned long nr_to_scan,
- nodemask_t *nodes_to_walk)
+ nodemask_t *nodes_to_walk, struct mem_cgroup *memcg)
{
LIST_HEAD(dispose);
long freed;
- freed = list_lru_walk_nodemask(&sb->s_dentry_lru, dentry_lru_isolate,
- &dispose, nr_to_scan, nodes_to_walk);
+ freed = list_lru_walk_nodemask_memcg(&sb->s_dentry_lru,
+ dentry_lru_isolate, &dispose, nr_to_scan, nodes_to_walk, memcg);
shrink_dentry_list(&dispose);
return freed;
}
diff --git a/fs/inode.c b/fs/inode.c
index 3cf4cb0..6565d88 100644
--- a/fs/inode.c
+++ b/fs/inode.c
@@ -747,13 +747,13 @@ inode_lru_isolate(struct list_head *item, spinlock_t *lru_lock, void *arg)
* then are freed outside inode_lock by dispose_list().
*/
long prune_icache_sb(struct super_block *sb, unsigned long nr_to_scan,
- nodemask_t *nodes_to_walk)
+ nodemask_t *nodes_to_walk, struct mem_cgroup *memcg)
{
LIST_HEAD(freeable);
long freed;
- freed = list_lru_walk_nodemask(&sb->s_inode_lru, inode_lru_isolate,
- &freeable, nr_to_scan, nodes_to_walk);
+ freed = list_lru_walk_nodemask_memcg(&sb->s_inode_lru,
+ inode_lru_isolate, &freeable, nr_to_scan, nodes_to_walk, memcg);
dispose_list(&freeable);
return freed;
}
diff --git a/fs/internal.h b/fs/internal.h
index 91900f2..068c7f7 100644
--- a/fs/internal.h
+++ b/fs/internal.h
@@ -16,6 +16,7 @@ struct file_system_type;
struct linux_binprm;
struct path;
struct mount;
+struct mem_cgroup;
/*
* block_dev.c
@@ -111,7 +112,7 @@ extern int open_check_o_direct(struct file *f);
*/
extern spinlock_t inode_sb_list_lock;
extern long prune_icache_sb(struct super_block *sb, unsigned long nr_to_scan,
- nodemask_t *nodes_to_scan);
+ nodemask_t *nodes_to_scan, struct mem_cgroup *memcg);
extern void inode_add_lru(struct inode *inode);
/*
@@ -128,7 +129,7 @@ extern int invalidate_inodes(struct super_block *, bool);
*/
extern struct dentry *__d_alloc(struct super_block *, const struct qstr *);
extern long prune_dcache_sb(struct super_block *sb, unsigned long nr_to_scan,
- nodemask_t *nodes_to_scan);
+ nodemask_t *nodes_to_scan, struct mem_cgroup *memcg);
/*
* read_write.c
diff --git a/fs/super.c b/fs/super.c
index 5c7b879..e92ebcb 100644
--- a/fs/super.c
+++ b/fs/super.c
@@ -34,6 +34,7 @@
#include <linux/cleancache.h>
#include <linux/fsnotify.h>
#include <linux/lockdep.h>
+#include <linux/memcontrol.h>
#include "internal.h"
@@ -56,6 +57,7 @@ static char *sb_writers_name[SB_FREEZE_LEVELS] = {
static long super_cache_scan(struct shrinker *shrink, struct shrink_control *sc)
{
struct super_block *sb;
+ struct mem_cgroup *memcg = sc->target_mem_cgroup;
long fs_objects = 0;
long total_objects;
long freed = 0;
@@ -74,11 +76,13 @@ static long super_cache_scan(struct shrinker *shrink, struct shrink_control *sc)
if (!grab_super_passive(sb))
return -1;
- if (sb->s_op && sb->s_op->nr_cached_objects)
+ if (sb->s_op && sb->s_op->nr_cached_objects && !memcg)
fs_objects = sb->s_op->nr_cached_objects(sb, &sc->nodes_to_scan);
- inodes = list_lru_count_nodemask(&sb->s_inode_lru, &sc->nodes_to_scan);
- dentries = list_lru_count_nodemask(&sb->s_dentry_lru, &sc->nodes_to_scan);
+ inodes = list_lru_count_nodemask_memcg(&sb->s_inode_lru,
+ &sc->nodes_to_scan, memcg);
+ dentries = list_lru_count_nodemask_memcg(&sb->s_dentry_lru,
+ &sc->nodes_to_scan, memcg);
total_objects = dentries + inodes + fs_objects + 1;
/* proportion the scan between the caches */
@@ -89,8 +93,8 @@ static long super_cache_scan(struct shrinker *shrink, struct shrink_control *sc)
* prune the dcache first as the icache is pinned by it, then
* prune the icache, followed by the filesystem specific caches
*/
- freed = prune_dcache_sb(sb, dentries, &sc->nodes_to_scan);
- freed += prune_icache_sb(sb, inodes, &sc->nodes_to_scan);
+ freed = prune_dcache_sb(sb, dentries, &sc->nodes_to_scan, memcg);
+ freed += prune_icache_sb(sb, inodes, &sc->nodes_to_scan, memcg);
if (fs_objects) {
fs_objects = mult_frac(sc->nr_to_scan, fs_objects,
@@ -107,20 +111,26 @@ static long super_cache_count(struct shrinker *shrink, struct shrink_control *sc
{
struct super_block *sb;
long total_objects = 0;
+ struct mem_cgroup *memcg = sc->target_mem_cgroup;
sb = container_of(shrink, struct super_block, s_shrink);
if (!grab_super_passive(sb))
return -1;
- if (sb->s_op && sb->s_op->nr_cached_objects)
+ /*
+ * Ideally we would pass memcg to nr_cached_objects, and
+ * let the underlying filesystem decide. Most likely the
+ * path will be if (!memcg) return;, but even then.
+ */
+ if (sb->s_op && sb->s_op->nr_cached_objects && !memcg)
total_objects = sb->s_op->nr_cached_objects(sb,
&sc->nodes_to_scan);
- total_objects += list_lru_count_nodemask(&sb->s_dentry_lru,
- &sc->nodes_to_scan);
- total_objects += list_lru_count_nodemask(&sb->s_inode_lru,
- &sc->nodes_to_scan);
+ total_objects += list_lru_count_nodemask_memcg(&sb->s_dentry_lru,
+ &sc->nodes_to_scan, memcg);
+ total_objects += list_lru_count_nodemask_memcg(&sb->s_inode_lru,
+ &sc->nodes_to_scan, memcg);
total_objects = vfs_pressure_ratio(total_objects);
drop_super(sb);
@@ -199,8 +209,10 @@ static struct super_block *alloc_super(struct file_system_type *type, int flags)
INIT_HLIST_NODE(&s->s_instances);
INIT_HLIST_BL_HEAD(&s->s_anon);
INIT_LIST_HEAD(&s->s_inodes);
- list_lru_init(&s->s_dentry_lru);
- list_lru_init(&s->s_inode_lru);
+
+ list_lru_init_memcg(&s->s_dentry_lru);
+ list_lru_init_memcg(&s->s_inode_lru);
+
INIT_LIST_HEAD(&s->s_mounts);
init_rwsem(&s->s_umount);
lockdep_set_class(&s->s_umount, &type->s_umount_key);
@@ -236,6 +248,7 @@ static struct super_block *alloc_super(struct file_system_type *type, int flags)
s->s_shrink.scan_objects = super_cache_scan;
s->s_shrink.count_objects = super_cache_count;
s->s_shrink.batch = 1024;
+ s->s_shrink.memcg_shrinker = true;
}
out:
return s;
@@ -318,6 +331,8 @@ void deactivate_locked_super(struct super_block *s)
/* caches are now gone, we can safely kill the shrinker now */
unregister_shrinker(&s->s_shrink);
+ list_lru_destroy(&s->s_dentry_lru);
+ list_lru_destroy(&s->s_inode_lru);
put_filesystem(fs);
put_super(s);
} else {
--
1.8.1.4
^ permalink raw reply related [flat|nested] 151+ messages in thread* [PATCH v6 28/31] super: targeted memcg reclaim
@ 2013-05-12 18:13 ` Glauber Costa
0 siblings, 0 replies; 151+ messages in thread
From: Glauber Costa @ 2013-05-12 18:13 UTC (permalink / raw)
To: linux-mm
Cc: cgroups, Andrew Morton, Greg Thelen, kamezawa.hiroyu,
Michal Hocko, Johannes Weiner, linux-fsdevel, Dave Chinner,
Glauber Costa, Dave Chinner, Mel Gorman, Rik van Riel,
Hugh Dickins
We now have all our dentries and inodes placed in memcg-specific LRU
lists. All we have to do is restrict the reclaim to the said lists in
case of memcg pressure.
That can't be done so easily for the fs_objects part of the equation,
since this is heavily fs-specific. What we do is pass on the context,
and let the filesystems decide if they ever chose or want to. At this
time, we just don't shrink them in memcg pressure (none is supported),
leaving that for global pressure only.
Marking the superblock shrinker and its LRUs as memcg-aware will
guarantee that the shrinkers will get invoked during targetted reclaim.
Signed-off-by: Glauber Costa <glommer@openvz.org>
Cc: Dave Chinner <dchinner@redhat.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Rik van Riel <riel@redhat.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Michal Hocko <mhocko@suse.cz>
Cc: Hugh Dickins <hughd@google.com>
Cc: Kamezawa Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
---
fs/dcache.c | 6 +++---
fs/inode.c | 6 +++---
fs/internal.h | 5 +++--
fs/super.c | 39 +++++++++++++++++++++++++++------------
4 files changed, 36 insertions(+), 20 deletions(-)
diff --git a/fs/dcache.c b/fs/dcache.c
index 20ab9c0..5eda937 100644
--- a/fs/dcache.c
+++ b/fs/dcache.c
@@ -885,13 +885,13 @@ dentry_lru_isolate(struct list_head *item, spinlock_t *lru_lock, void *arg)
* use.
*/
long prune_dcache_sb(struct super_block *sb, unsigned long nr_to_scan,
- nodemask_t *nodes_to_walk)
+ nodemask_t *nodes_to_walk, struct mem_cgroup *memcg)
{
LIST_HEAD(dispose);
long freed;
- freed = list_lru_walk_nodemask(&sb->s_dentry_lru, dentry_lru_isolate,
- &dispose, nr_to_scan, nodes_to_walk);
+ freed = list_lru_walk_nodemask_memcg(&sb->s_dentry_lru,
+ dentry_lru_isolate, &dispose, nr_to_scan, nodes_to_walk, memcg);
shrink_dentry_list(&dispose);
return freed;
}
diff --git a/fs/inode.c b/fs/inode.c
index 3cf4cb0..6565d88 100644
--- a/fs/inode.c
+++ b/fs/inode.c
@@ -747,13 +747,13 @@ inode_lru_isolate(struct list_head *item, spinlock_t *lru_lock, void *arg)
* then are freed outside inode_lock by dispose_list().
*/
long prune_icache_sb(struct super_block *sb, unsigned long nr_to_scan,
- nodemask_t *nodes_to_walk)
+ nodemask_t *nodes_to_walk, struct mem_cgroup *memcg)
{
LIST_HEAD(freeable);
long freed;
- freed = list_lru_walk_nodemask(&sb->s_inode_lru, inode_lru_isolate,
- &freeable, nr_to_scan, nodes_to_walk);
+ freed = list_lru_walk_nodemask_memcg(&sb->s_inode_lru,
+ inode_lru_isolate, &freeable, nr_to_scan, nodes_to_walk, memcg);
dispose_list(&freeable);
return freed;
}
diff --git a/fs/internal.h b/fs/internal.h
index 91900f2..068c7f7 100644
--- a/fs/internal.h
+++ b/fs/internal.h
@@ -16,6 +16,7 @@ struct file_system_type;
struct linux_binprm;
struct path;
struct mount;
+struct mem_cgroup;
/*
* block_dev.c
@@ -111,7 +112,7 @@ extern int open_check_o_direct(struct file *f);
*/
extern spinlock_t inode_sb_list_lock;
extern long prune_icache_sb(struct super_block *sb, unsigned long nr_to_scan,
- nodemask_t *nodes_to_scan);
+ nodemask_t *nodes_to_scan, struct mem_cgroup *memcg);
extern void inode_add_lru(struct inode *inode);
/*
@@ -128,7 +129,7 @@ extern int invalidate_inodes(struct super_block *, bool);
*/
extern struct dentry *__d_alloc(struct super_block *, const struct qstr *);
extern long prune_dcache_sb(struct super_block *sb, unsigned long nr_to_scan,
- nodemask_t *nodes_to_scan);
+ nodemask_t *nodes_to_scan, struct mem_cgroup *memcg);
/*
* read_write.c
diff --git a/fs/super.c b/fs/super.c
index 5c7b879..e92ebcb 100644
--- a/fs/super.c
+++ b/fs/super.c
@@ -34,6 +34,7 @@
#include <linux/cleancache.h>
#include <linux/fsnotify.h>
#include <linux/lockdep.h>
+#include <linux/memcontrol.h>
#include "internal.h"
@@ -56,6 +57,7 @@ static char *sb_writers_name[SB_FREEZE_LEVELS] = {
static long super_cache_scan(struct shrinker *shrink, struct shrink_control *sc)
{
struct super_block *sb;
+ struct mem_cgroup *memcg = sc->target_mem_cgroup;
long fs_objects = 0;
long total_objects;
long freed = 0;
@@ -74,11 +76,13 @@ static long super_cache_scan(struct shrinker *shrink, struct shrink_control *sc)
if (!grab_super_passive(sb))
return -1;
- if (sb->s_op && sb->s_op->nr_cached_objects)
+ if (sb->s_op && sb->s_op->nr_cached_objects && !memcg)
fs_objects = sb->s_op->nr_cached_objects(sb, &sc->nodes_to_scan);
- inodes = list_lru_count_nodemask(&sb->s_inode_lru, &sc->nodes_to_scan);
- dentries = list_lru_count_nodemask(&sb->s_dentry_lru, &sc->nodes_to_scan);
+ inodes = list_lru_count_nodemask_memcg(&sb->s_inode_lru,
+ &sc->nodes_to_scan, memcg);
+ dentries = list_lru_count_nodemask_memcg(&sb->s_dentry_lru,
+ &sc->nodes_to_scan, memcg);
total_objects = dentries + inodes + fs_objects + 1;
/* proportion the scan between the caches */
@@ -89,8 +93,8 @@ static long super_cache_scan(struct shrinker *shrink, struct shrink_control *sc)
* prune the dcache first as the icache is pinned by it, then
* prune the icache, followed by the filesystem specific caches
*/
- freed = prune_dcache_sb(sb, dentries, &sc->nodes_to_scan);
- freed += prune_icache_sb(sb, inodes, &sc->nodes_to_scan);
+ freed = prune_dcache_sb(sb, dentries, &sc->nodes_to_scan, memcg);
+ freed += prune_icache_sb(sb, inodes, &sc->nodes_to_scan, memcg);
if (fs_objects) {
fs_objects = mult_frac(sc->nr_to_scan, fs_objects,
@@ -107,20 +111,26 @@ static long super_cache_count(struct shrinker *shrink, struct shrink_control *sc
{
struct super_block *sb;
long total_objects = 0;
+ struct mem_cgroup *memcg = sc->target_mem_cgroup;
sb = container_of(shrink, struct super_block, s_shrink);
if (!grab_super_passive(sb))
return -1;
- if (sb->s_op && sb->s_op->nr_cached_objects)
+ /*
+ * Ideally we would pass memcg to nr_cached_objects, and
+ * let the underlying filesystem decide. Most likely the
+ * path will be if (!memcg) return;, but even then.
+ */
+ if (sb->s_op && sb->s_op->nr_cached_objects && !memcg)
total_objects = sb->s_op->nr_cached_objects(sb,
&sc->nodes_to_scan);
- total_objects += list_lru_count_nodemask(&sb->s_dentry_lru,
- &sc->nodes_to_scan);
- total_objects += list_lru_count_nodemask(&sb->s_inode_lru,
- &sc->nodes_to_scan);
+ total_objects += list_lru_count_nodemask_memcg(&sb->s_dentry_lru,
+ &sc->nodes_to_scan, memcg);
+ total_objects += list_lru_count_nodemask_memcg(&sb->s_inode_lru,
+ &sc->nodes_to_scan, memcg);
total_objects = vfs_pressure_ratio(total_objects);
drop_super(sb);
@@ -199,8 +209,10 @@ static struct super_block *alloc_super(struct file_system_type *type, int flags)
INIT_HLIST_NODE(&s->s_instances);
INIT_HLIST_BL_HEAD(&s->s_anon);
INIT_LIST_HEAD(&s->s_inodes);
- list_lru_init(&s->s_dentry_lru);
- list_lru_init(&s->s_inode_lru);
+
+ list_lru_init_memcg(&s->s_dentry_lru);
+ list_lru_init_memcg(&s->s_inode_lru);
+
INIT_LIST_HEAD(&s->s_mounts);
init_rwsem(&s->s_umount);
lockdep_set_class(&s->s_umount, &type->s_umount_key);
@@ -236,6 +248,7 @@ static struct super_block *alloc_super(struct file_system_type *type, int flags)
s->s_shrink.scan_objects = super_cache_scan;
s->s_shrink.count_objects = super_cache_count;
s->s_shrink.batch = 1024;
+ s->s_shrink.memcg_shrinker = true;
}
out:
return s;
@@ -318,6 +331,8 @@ void deactivate_locked_super(struct super_block *s)
/* caches are now gone, we can safely kill the shrinker now */
unregister_shrinker(&s->s_shrink);
+ list_lru_destroy(&s->s_dentry_lru);
+ list_lru_destroy(&s->s_inode_lru);
put_filesystem(fs);
put_super(s);
} else {
--
1.8.1.4
--
To unsubscribe, send a message with 'unsubscribe linux-mm' in
the body to majordomo@kvack.org. For more info on Linux MM,
see: http://www.linux-mm.org/ .
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^ permalink raw reply related [flat|nested] 151+ messages in thread
* [PATCH v6 29/31] memcg: move initialization to memcg creation
2013-05-12 18:13 ` Glauber Costa
(?)
@ 2013-05-12 18:13 ` Glauber Costa
-1 siblings, 0 replies; 151+ messages in thread
From: Glauber Costa @ 2013-05-12 18:13 UTC (permalink / raw)
To: linux-mm
Cc: cgroups, Andrew Morton, Greg Thelen, kamezawa.hiroyu,
Michal Hocko, Johannes Weiner, linux-fsdevel, Dave Chinner,
Glauber Costa, Dave Chinner, Mel Gorman, Rik van Riel,
Hugh Dickins
Those structures are only used for memcgs that are effectively using
kmemcg. However, in a later patch I intend to use scan that list
inconditionally (list empty meaning no kmem caches present), which
simplifies the code a lot.
So move the initialization to early kmem creation.
Signed-off-by: Glauber Costa <glommer@openvz.org>
Cc: Dave Chinner <dchinner@redhat.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Rik van Riel <riel@redhat.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Michal Hocko <mhocko@suse.cz>
Cc: Hugh Dickins <hughd@google.com>
Cc: Kamezawa Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
---
mm/memcontrol.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index b8980d1..6f6a330 100644
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -3323,9 +3323,7 @@ int memcg_update_cache_sizes(struct mem_cgroup *memcg)
memcg_update_array_size(num + 1);
- INIT_LIST_HEAD(&memcg->memcg_slab_caches);
INIT_WORK(&memcg->kmemcg_shrink_work, kmemcg_shrink_work_fn);
- mutex_init(&memcg->slab_caches_mutex);
return 0;
out:
@@ -6318,6 +6316,8 @@ static int memcg_init_kmem(struct mem_cgroup *memcg, struct cgroup_subsys *ss)
{
int ret;
+ INIT_LIST_HEAD(&memcg->memcg_slab_caches);
+ mutex_init(&memcg->slab_caches_mutex);
memcg->kmemcg_id = -1;
ret = memcg_propagate_kmem(memcg);
if (ret)
--
1.8.1.4
^ permalink raw reply related [flat|nested] 151+ messages in thread* [PATCH v6 29/31] memcg: move initialization to memcg creation
@ 2013-05-12 18:13 ` Glauber Costa
0 siblings, 0 replies; 151+ messages in thread
From: Glauber Costa @ 2013-05-12 18:13 UTC (permalink / raw)
To: linux-mm
Cc: cgroups, Andrew Morton, Greg Thelen, kamezawa.hiroyu,
Michal Hocko, Johannes Weiner, linux-fsdevel, Dave Chinner,
Glauber Costa, Dave Chinner, Mel Gorman, Rik van Riel,
Hugh Dickins
Those structures are only used for memcgs that are effectively using
kmemcg. However, in a later patch I intend to use scan that list
inconditionally (list empty meaning no kmem caches present), which
simplifies the code a lot.
So move the initialization to early kmem creation.
Signed-off-by: Glauber Costa <glommer@openvz.org>
Cc: Dave Chinner <dchinner@redhat.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Rik van Riel <riel@redhat.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Michal Hocko <mhocko@suse.cz>
Cc: Hugh Dickins <hughd@google.com>
Cc: Kamezawa Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
---
mm/memcontrol.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index b8980d1..6f6a330 100644
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -3323,9 +3323,7 @@ int memcg_update_cache_sizes(struct mem_cgroup *memcg)
memcg_update_array_size(num + 1);
- INIT_LIST_HEAD(&memcg->memcg_slab_caches);
INIT_WORK(&memcg->kmemcg_shrink_work, kmemcg_shrink_work_fn);
- mutex_init(&memcg->slab_caches_mutex);
return 0;
out:
@@ -6318,6 +6316,8 @@ static int memcg_init_kmem(struct mem_cgroup *memcg, struct cgroup_subsys *ss)
{
int ret;
+ INIT_LIST_HEAD(&memcg->memcg_slab_caches);
+ mutex_init(&memcg->slab_caches_mutex);
memcg->kmemcg_id = -1;
ret = memcg_propagate_kmem(memcg);
if (ret)
--
1.8.1.4
^ permalink raw reply related [flat|nested] 151+ messages in thread* [PATCH v6 29/31] memcg: move initialization to memcg creation
@ 2013-05-12 18:13 ` Glauber Costa
0 siblings, 0 replies; 151+ messages in thread
From: Glauber Costa @ 2013-05-12 18:13 UTC (permalink / raw)
To: linux-mm
Cc: cgroups, Andrew Morton, Greg Thelen, kamezawa.hiroyu,
Michal Hocko, Johannes Weiner, linux-fsdevel, Dave Chinner,
Glauber Costa, Dave Chinner, Mel Gorman, Rik van Riel,
Hugh Dickins
Those structures are only used for memcgs that are effectively using
kmemcg. However, in a later patch I intend to use scan that list
inconditionally (list empty meaning no kmem caches present), which
simplifies the code a lot.
So move the initialization to early kmem creation.
Signed-off-by: Glauber Costa <glommer@openvz.org>
Cc: Dave Chinner <dchinner@redhat.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Rik van Riel <riel@redhat.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Michal Hocko <mhocko@suse.cz>
Cc: Hugh Dickins <hughd@google.com>
Cc: Kamezawa Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
---
mm/memcontrol.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index b8980d1..6f6a330 100644
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -3323,9 +3323,7 @@ int memcg_update_cache_sizes(struct mem_cgroup *memcg)
memcg_update_array_size(num + 1);
- INIT_LIST_HEAD(&memcg->memcg_slab_caches);
INIT_WORK(&memcg->kmemcg_shrink_work, kmemcg_shrink_work_fn);
- mutex_init(&memcg->slab_caches_mutex);
return 0;
out:
@@ -6318,6 +6316,8 @@ static int memcg_init_kmem(struct mem_cgroup *memcg, struct cgroup_subsys *ss)
{
int ret;
+ INIT_LIST_HEAD(&memcg->memcg_slab_caches);
+ mutex_init(&memcg->slab_caches_mutex);
memcg->kmemcg_id = -1;
ret = memcg_propagate_kmem(memcg);
if (ret)
--
1.8.1.4
--
To unsubscribe, send a message with 'unsubscribe linux-mm' in
the body to majordomo@kvack.org. For more info on Linux MM,
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^ permalink raw reply related [flat|nested] 151+ messages in thread
* [PATCH v6 30/31] vmpressure: in-kernel notifications
2013-05-12 18:13 ` Glauber Costa
(?)
@ 2013-05-12 18:13 ` Glauber Costa
-1 siblings, 0 replies; 151+ messages in thread
From: Glauber Costa @ 2013-05-12 18:13 UTC (permalink / raw)
To: linux-mm
Cc: cgroups, Andrew Morton, Greg Thelen, kamezawa.hiroyu,
Michal Hocko, Johannes Weiner, linux-fsdevel, Dave Chinner,
Glauber Costa, John Stultz, Joonsoo Kim
From: Glauber Costa <glommer@parallels.com>
During the past weeks, it became clear to us that the shrinker interface
we have right now works very well for some particular types of users,
but not that well for others. The later are usually people interested in
one-shot notifications, that were forced to adapt themselves to the
count+scan behavior of shrinkers. To do so, they had no choice than to
greatly abuse the shrinker interface producing little monsters all over.
During LSF/MM, one of the proposals that popped out during our session
was to reuse Anton Voronstsov's vmpressure for this. They are designed
for userspace consumption, but also provide a well-stablished,
cgroup-aware entry point for notifications.
This patch extends that to also support in-kernel users. Events that
should be generated for in-kernel consumption will be marked as such,
and for those, we will call a registered function instead of triggering
an eventfd notification.
Please note that due to my lack of understanding of each shrinker user,
I will stay away from converting the actual users, you are all welcome
to do so.
Signed-off-by: Glauber Costa <glommer@openvz.org>
Acked-by: Anton Vorontsov <anton@enomsg.org>
Acked-by: Pekka Enberg <penberg@kernel.org>
Reviewed-by: Greg Thelen <gthelen@google.com>
Cc: Dave Chinner <david@fromorbit.com>
Cc: John Stultz <john.stultz@linaro.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Joonsoo Kim <js1304@gmail.com>
Cc: Michal Hocko <mhocko@suse.cz>
Cc: Kamezawa Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
---
include/linux/vmpressure.h | 6 ++++++
mm/vmpressure.c | 52 +++++++++++++++++++++++++++++++++++++++++++---
2 files changed, 55 insertions(+), 3 deletions(-)
diff --git a/include/linux/vmpressure.h b/include/linux/vmpressure.h
index 76be077..3131e72 100644
--- a/include/linux/vmpressure.h
+++ b/include/linux/vmpressure.h
@@ -19,6 +19,9 @@ struct vmpressure {
/* Have to grab the lock on events traversal or modifications. */
struct mutex events_lock;
+ /* False if only kernel users want to be notified, true otherwise. */
+ bool notify_userspace;
+
struct work_struct work;
};
@@ -36,6 +39,9 @@ extern struct vmpressure *css_to_vmpressure(struct cgroup_subsys_state *css);
extern int vmpressure_register_event(struct cgroup *cg, struct cftype *cft,
struct eventfd_ctx *eventfd,
const char *args);
+
+extern int vmpressure_register_kernel_event(struct cgroup *cg,
+ void (*fn)(void));
extern void vmpressure_unregister_event(struct cgroup *cg, struct cftype *cft,
struct eventfd_ctx *eventfd);
#else
diff --git a/mm/vmpressure.c b/mm/vmpressure.c
index 736a601..e16256e 100644
--- a/mm/vmpressure.c
+++ b/mm/vmpressure.c
@@ -135,8 +135,12 @@ static enum vmpressure_levels vmpressure_calc_level(unsigned long scanned,
}
struct vmpressure_event {
- struct eventfd_ctx *efd;
+ union {
+ struct eventfd_ctx *efd;
+ void (*fn)(void);
+ };
enum vmpressure_levels level;
+ bool kernel_event;
struct list_head node;
};
@@ -152,12 +156,15 @@ static bool vmpressure_event(struct vmpressure *vmpr,
mutex_lock(&vmpr->events_lock);
list_for_each_entry(ev, &vmpr->events, node) {
- if (level >= ev->level) {
+ if (ev->kernel_event) {
+ ev->fn();
+ } else if (vmpr->notify_userspace && level >= ev->level) {
eventfd_signal(ev->efd, 1);
signalled = true;
}
}
+ vmpr->notify_userspace = false;
mutex_unlock(&vmpr->events_lock);
return signalled;
@@ -227,7 +234,7 @@ void vmpressure(gfp_t gfp, struct mem_cgroup *memcg,
* we account it too.
*/
if (!(gfp & (__GFP_HIGHMEM | __GFP_MOVABLE | __GFP_IO | __GFP_FS)))
- return;
+ goto schedule;
/*
* If we got here with no pages scanned, then that is an indicator
@@ -244,8 +251,15 @@ void vmpressure(gfp_t gfp, struct mem_cgroup *memcg,
vmpr->scanned += scanned;
vmpr->reclaimed += reclaimed;
scanned = vmpr->scanned;
+ /*
+ * If we didn't reach this point, only kernel events will be triggered.
+ * It is the job of the worker thread to clean this up once the
+ * notifications are all delivered.
+ */
+ vmpr->notify_userspace = true;
mutex_unlock(&vmpr->sr_lock);
+schedule:
if (scanned < vmpressure_win || work_pending(&vmpr->work))
return;
schedule_work(&vmpr->work);
@@ -328,6 +342,38 @@ int vmpressure_register_event(struct cgroup *cg, struct cftype *cft,
}
/**
+ * vmpressure_register_kernel_event() - Register kernel-side notification
+ * @cg: cgroup that is interested in vmpressure notifications
+ * @fn: function to be called when pressure happens
+ *
+ * This function register in-kernel users interested in receiving notifications
+ * about pressure conditions. Pressure notifications will be triggered at the
+ * same time as userspace notifications (with no particular ordering relative
+ * to it).
+ *
+ * Pressure notifications are a alternative method to shrinkers and will serve
+ * well users that are interested in a one-shot notification, with a
+ * well-defined cgroup aware interface.
+ */
+int vmpressure_register_kernel_event(struct cgroup *cg, void (*fn)(void))
+{
+ struct vmpressure *vmpr = cg_to_vmpressure(cg);
+ struct vmpressure_event *ev;
+
+ ev = kzalloc(sizeof(*ev), GFP_KERNEL);
+ if (!ev)
+ return -ENOMEM;
+
+ ev->kernel_event = true;
+ ev->fn = fn;
+
+ mutex_lock(&vmpr->events_lock);
+ list_add(&ev->node, &vmpr->events);
+ mutex_unlock(&vmpr->events_lock);
+ return 0;
+}
+
+/**
* vmpressure_unregister_event() - Unbind eventfd from vmpressure
* @cg: cgroup handle
* @cft: cgroup control files handle
--
1.8.1.4
^ permalink raw reply related [flat|nested] 151+ messages in thread* [PATCH v6 30/31] vmpressure: in-kernel notifications
@ 2013-05-12 18:13 ` Glauber Costa
0 siblings, 0 replies; 151+ messages in thread
From: Glauber Costa @ 2013-05-12 18:13 UTC (permalink / raw)
To: linux-mm
Cc: cgroups, Andrew Morton, Greg Thelen, kamezawa.hiroyu,
Michal Hocko, Johannes Weiner, linux-fsdevel, Dave Chinner,
Glauber Costa, John Stultz, Joonsoo Kim
From: Glauber Costa <glommer@parallels.com>
During the past weeks, it became clear to us that the shrinker interface
we have right now works very well for some particular types of users,
but not that well for others. The later are usually people interested in
one-shot notifications, that were forced to adapt themselves to the
count+scan behavior of shrinkers. To do so, they had no choice than to
greatly abuse the shrinker interface producing little monsters all over.
During LSF/MM, one of the proposals that popped out during our session
was to reuse Anton Voronstsov's vmpressure for this. They are designed
for userspace consumption, but also provide a well-stablished,
cgroup-aware entry point for notifications.
This patch extends that to also support in-kernel users. Events that
should be generated for in-kernel consumption will be marked as such,
and for those, we will call a registered function instead of triggering
an eventfd notification.
Please note that due to my lack of understanding of each shrinker user,
I will stay away from converting the actual users, you are all welcome
to do so.
Signed-off-by: Glauber Costa <glommer@openvz.org>
Acked-by: Anton Vorontsov <anton@enomsg.org>
Acked-by: Pekka Enberg <penberg@kernel.org>
Reviewed-by: Greg Thelen <gthelen@google.com>
Cc: Dave Chinner <david@fromorbit.com>
Cc: John Stultz <john.stultz@linaro.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Joonsoo Kim <js1304@gmail.com>
Cc: Michal Hocko <mhocko@suse.cz>
Cc: Kamezawa Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
---
include/linux/vmpressure.h | 6 ++++++
mm/vmpressure.c | 52 +++++++++++++++++++++++++++++++++++++++++++---
2 files changed, 55 insertions(+), 3 deletions(-)
diff --git a/include/linux/vmpressure.h b/include/linux/vmpressure.h
index 76be077..3131e72 100644
--- a/include/linux/vmpressure.h
+++ b/include/linux/vmpressure.h
@@ -19,6 +19,9 @@ struct vmpressure {
/* Have to grab the lock on events traversal or modifications. */
struct mutex events_lock;
+ /* False if only kernel users want to be notified, true otherwise. */
+ bool notify_userspace;
+
struct work_struct work;
};
@@ -36,6 +39,9 @@ extern struct vmpressure *css_to_vmpressure(struct cgroup_subsys_state *css);
extern int vmpressure_register_event(struct cgroup *cg, struct cftype *cft,
struct eventfd_ctx *eventfd,
const char *args);
+
+extern int vmpressure_register_kernel_event(struct cgroup *cg,
+ void (*fn)(void));
extern void vmpressure_unregister_event(struct cgroup *cg, struct cftype *cft,
struct eventfd_ctx *eventfd);
#else
diff --git a/mm/vmpressure.c b/mm/vmpressure.c
index 736a601..e16256e 100644
--- a/mm/vmpressure.c
+++ b/mm/vmpressure.c
@@ -135,8 +135,12 @@ static enum vmpressure_levels vmpressure_calc_level(unsigned long scanned,
}
struct vmpressure_event {
- struct eventfd_ctx *efd;
+ union {
+ struct eventfd_ctx *efd;
+ void (*fn)(void);
+ };
enum vmpressure_levels level;
+ bool kernel_event;
struct list_head node;
};
@@ -152,12 +156,15 @@ static bool vmpressure_event(struct vmpressure *vmpr,
mutex_lock(&vmpr->events_lock);
list_for_each_entry(ev, &vmpr->events, node) {
- if (level >= ev->level) {
+ if (ev->kernel_event) {
+ ev->fn();
+ } else if (vmpr->notify_userspace && level >= ev->level) {
eventfd_signal(ev->efd, 1);
signalled = true;
}
}
+ vmpr->notify_userspace = false;
mutex_unlock(&vmpr->events_lock);
return signalled;
@@ -227,7 +234,7 @@ void vmpressure(gfp_t gfp, struct mem_cgroup *memcg,
* we account it too.
*/
if (!(gfp & (__GFP_HIGHMEM | __GFP_MOVABLE | __GFP_IO | __GFP_FS)))
- return;
+ goto schedule;
/*
* If we got here with no pages scanned, then that is an indicator
@@ -244,8 +251,15 @@ void vmpressure(gfp_t gfp, struct mem_cgroup *memcg,
vmpr->scanned += scanned;
vmpr->reclaimed += reclaimed;
scanned = vmpr->scanned;
+ /*
+ * If we didn't reach this point, only kernel events will be triggered.
+ * It is the job of the worker thread to clean this up once the
+ * notifications are all delivered.
+ */
+ vmpr->notify_userspace = true;
mutex_unlock(&vmpr->sr_lock);
+schedule:
if (scanned < vmpressure_win || work_pending(&vmpr->work))
return;
schedule_work(&vmpr->work);
@@ -328,6 +342,38 @@ int vmpressure_register_event(struct cgroup *cg, struct cftype *cft,
}
/**
+ * vmpressure_register_kernel_event() - Register kernel-side notification
+ * @cg: cgroup that is interested in vmpressure notifications
+ * @fn: function to be called when pressure happens
+ *
+ * This function register in-kernel users interested in receiving notifications
+ * about pressure conditions. Pressure notifications will be triggered at the
+ * same time as userspace notifications (with no particular ordering relative
+ * to it).
+ *
+ * Pressure notifications are a alternative method to shrinkers and will serve
+ * well users that are interested in a one-shot notification, with a
+ * well-defined cgroup aware interface.
+ */
+int vmpressure_register_kernel_event(struct cgroup *cg, void (*fn)(void))
+{
+ struct vmpressure *vmpr = cg_to_vmpressure(cg);
+ struct vmpressure_event *ev;
+
+ ev = kzalloc(sizeof(*ev), GFP_KERNEL);
+ if (!ev)
+ return -ENOMEM;
+
+ ev->kernel_event = true;
+ ev->fn = fn;
+
+ mutex_lock(&vmpr->events_lock);
+ list_add(&ev->node, &vmpr->events);
+ mutex_unlock(&vmpr->events_lock);
+ return 0;
+}
+
+/**
* vmpressure_unregister_event() - Unbind eventfd from vmpressure
* @cg: cgroup handle
* @cft: cgroup control files handle
--
1.8.1.4
^ permalink raw reply related [flat|nested] 151+ messages in thread* [PATCH v6 30/31] vmpressure: in-kernel notifications
@ 2013-05-12 18:13 ` Glauber Costa
0 siblings, 0 replies; 151+ messages in thread
From: Glauber Costa @ 2013-05-12 18:13 UTC (permalink / raw)
To: linux-mm
Cc: cgroups, Andrew Morton, Greg Thelen, kamezawa.hiroyu,
Michal Hocko, Johannes Weiner, linux-fsdevel, Dave Chinner,
Glauber Costa, John Stultz, Joonsoo Kim
From: Glauber Costa <glommer@parallels.com>
During the past weeks, it became clear to us that the shrinker interface
we have right now works very well for some particular types of users,
but not that well for others. The later are usually people interested in
one-shot notifications, that were forced to adapt themselves to the
count+scan behavior of shrinkers. To do so, they had no choice than to
greatly abuse the shrinker interface producing little monsters all over.
During LSF/MM, one of the proposals that popped out during our session
was to reuse Anton Voronstsov's vmpressure for this. They are designed
for userspace consumption, but also provide a well-stablished,
cgroup-aware entry point for notifications.
This patch extends that to also support in-kernel users. Events that
should be generated for in-kernel consumption will be marked as such,
and for those, we will call a registered function instead of triggering
an eventfd notification.
Please note that due to my lack of understanding of each shrinker user,
I will stay away from converting the actual users, you are all welcome
to do so.
Signed-off-by: Glauber Costa <glommer@openvz.org>
Acked-by: Anton Vorontsov <anton@enomsg.org>
Acked-by: Pekka Enberg <penberg@kernel.org>
Reviewed-by: Greg Thelen <gthelen@google.com>
Cc: Dave Chinner <david@fromorbit.com>
Cc: John Stultz <john.stultz@linaro.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Joonsoo Kim <js1304@gmail.com>
Cc: Michal Hocko <mhocko@suse.cz>
Cc: Kamezawa Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
---
include/linux/vmpressure.h | 6 ++++++
mm/vmpressure.c | 52 +++++++++++++++++++++++++++++++++++++++++++---
2 files changed, 55 insertions(+), 3 deletions(-)
diff --git a/include/linux/vmpressure.h b/include/linux/vmpressure.h
index 76be077..3131e72 100644
--- a/include/linux/vmpressure.h
+++ b/include/linux/vmpressure.h
@@ -19,6 +19,9 @@ struct vmpressure {
/* Have to grab the lock on events traversal or modifications. */
struct mutex events_lock;
+ /* False if only kernel users want to be notified, true otherwise. */
+ bool notify_userspace;
+
struct work_struct work;
};
@@ -36,6 +39,9 @@ extern struct vmpressure *css_to_vmpressure(struct cgroup_subsys_state *css);
extern int vmpressure_register_event(struct cgroup *cg, struct cftype *cft,
struct eventfd_ctx *eventfd,
const char *args);
+
+extern int vmpressure_register_kernel_event(struct cgroup *cg,
+ void (*fn)(void));
extern void vmpressure_unregister_event(struct cgroup *cg, struct cftype *cft,
struct eventfd_ctx *eventfd);
#else
diff --git a/mm/vmpressure.c b/mm/vmpressure.c
index 736a601..e16256e 100644
--- a/mm/vmpressure.c
+++ b/mm/vmpressure.c
@@ -135,8 +135,12 @@ static enum vmpressure_levels vmpressure_calc_level(unsigned long scanned,
}
struct vmpressure_event {
- struct eventfd_ctx *efd;
+ union {
+ struct eventfd_ctx *efd;
+ void (*fn)(void);
+ };
enum vmpressure_levels level;
+ bool kernel_event;
struct list_head node;
};
@@ -152,12 +156,15 @@ static bool vmpressure_event(struct vmpressure *vmpr,
mutex_lock(&vmpr->events_lock);
list_for_each_entry(ev, &vmpr->events, node) {
- if (level >= ev->level) {
+ if (ev->kernel_event) {
+ ev->fn();
+ } else if (vmpr->notify_userspace && level >= ev->level) {
eventfd_signal(ev->efd, 1);
signalled = true;
}
}
+ vmpr->notify_userspace = false;
mutex_unlock(&vmpr->events_lock);
return signalled;
@@ -227,7 +234,7 @@ void vmpressure(gfp_t gfp, struct mem_cgroup *memcg,
* we account it too.
*/
if (!(gfp & (__GFP_HIGHMEM | __GFP_MOVABLE | __GFP_IO | __GFP_FS)))
- return;
+ goto schedule;
/*
* If we got here with no pages scanned, then that is an indicator
@@ -244,8 +251,15 @@ void vmpressure(gfp_t gfp, struct mem_cgroup *memcg,
vmpr->scanned += scanned;
vmpr->reclaimed += reclaimed;
scanned = vmpr->scanned;
+ /*
+ * If we didn't reach this point, only kernel events will be triggered.
+ * It is the job of the worker thread to clean this up once the
+ * notifications are all delivered.
+ */
+ vmpr->notify_userspace = true;
mutex_unlock(&vmpr->sr_lock);
+schedule:
if (scanned < vmpressure_win || work_pending(&vmpr->work))
return;
schedule_work(&vmpr->work);
@@ -328,6 +342,38 @@ int vmpressure_register_event(struct cgroup *cg, struct cftype *cft,
}
/**
+ * vmpressure_register_kernel_event() - Register kernel-side notification
+ * @cg: cgroup that is interested in vmpressure notifications
+ * @fn: function to be called when pressure happens
+ *
+ * This function register in-kernel users interested in receiving notifications
+ * about pressure conditions. Pressure notifications will be triggered at the
+ * same time as userspace notifications (with no particular ordering relative
+ * to it).
+ *
+ * Pressure notifications are a alternative method to shrinkers and will serve
+ * well users that are interested in a one-shot notification, with a
+ * well-defined cgroup aware interface.
+ */
+int vmpressure_register_kernel_event(struct cgroup *cg, void (*fn)(void))
+{
+ struct vmpressure *vmpr = cg_to_vmpressure(cg);
+ struct vmpressure_event *ev;
+
+ ev = kzalloc(sizeof(*ev), GFP_KERNEL);
+ if (!ev)
+ return -ENOMEM;
+
+ ev->kernel_event = true;
+ ev->fn = fn;
+
+ mutex_lock(&vmpr->events_lock);
+ list_add(&ev->node, &vmpr->events);
+ mutex_unlock(&vmpr->events_lock);
+ return 0;
+}
+
+/**
* vmpressure_unregister_event() - Unbind eventfd from vmpressure
* @cg: cgroup handle
* @cft: cgroup control files handle
--
1.8.1.4
--
To unsubscribe, send a message with 'unsubscribe linux-mm' in
the body to majordomo@kvack.org. For more info on Linux MM,
see: http://www.linux-mm.org/ .
Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a>
^ permalink raw reply related [flat|nested] 151+ messages in thread
* [PATCH v6 31/31] memcg: reap dead memcgs upon global memory pressure.
2013-05-12 18:13 ` Glauber Costa
(?)
@ 2013-05-12 18:13 ` Glauber Costa
-1 siblings, 0 replies; 151+ messages in thread
From: Glauber Costa @ 2013-05-12 18:13 UTC (permalink / raw)
To: linux-mm
Cc: cgroups, Andrew Morton, Greg Thelen, kamezawa.hiroyu,
Michal Hocko, Johannes Weiner, linux-fsdevel, Dave Chinner,
Glauber Costa, Dave Chinner, Mel Gorman, Rik van Riel,
Hugh Dickins
When we delete kmem-enabled memcgs, they can still be zombieing
around for a while. The reason is that the objects may still be alive,
and we won't be able to delete them at destruction time.
The only entry point for that, though, are the shrinkers. The
shrinker interface, however, is not exactly tailored to our needs. It
could be a little bit better by using the API Dave Chinner proposed, but
it is still not ideal since we aren't really a count-and-scan event, but
more a one-off flush-all-you-can event that would have to abuse that
somehow.
Signed-off-by: Glauber Costa <glommer@openvz.org>
Cc: Dave Chinner <dchinner@redhat.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Rik van Riel <riel@redhat.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Michal Hocko <mhocko@suse.cz>
Cc: Hugh Dickins <hughd@google.com>
Cc: Kamezawa Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
---
mm/memcontrol.c | 52 ++++++++++++++++++++++++++++++++++++++++++++++------
1 file changed, 46 insertions(+), 6 deletions(-)
diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index 6f6a330..7006f03 100644
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -400,7 +400,6 @@ static size_t memcg_size(void)
nr_node_ids * sizeof(struct mem_cgroup_per_node);
}
-#ifdef CONFIG_MEMCG_DEBUG_ASYNC_DESTROY
static LIST_HEAD(dangling_memcgs);
static DEFINE_MUTEX(dangling_memcgs_mutex);
@@ -409,11 +408,14 @@ static inline void memcg_dangling_free(struct mem_cgroup *memcg)
mutex_lock(&dangling_memcgs_mutex);
list_del(&memcg->dead);
mutex_unlock(&dangling_memcgs_mutex);
+#ifdef CONFIG_MEMCG_DEBUG_ASYNC_DESTROY
free_pages((unsigned long)memcg->memcg_name, 0);
+#endif
}
static inline void memcg_dangling_add(struct mem_cgroup *memcg)
{
+#ifdef CONFIG_MEMCG_DEBUG_ASYNC_DESTROY
/*
* cgroup.c will do page-sized allocations most of the time,
* so we'll just follow the pattern. Also, __get_free_pages
@@ -439,15 +441,12 @@ static inline void memcg_dangling_add(struct mem_cgroup *memcg)
}
add_list:
+#endif
INIT_LIST_HEAD(&memcg->dead);
mutex_lock(&dangling_memcgs_mutex);
list_add(&memcg->dead, &dangling_memcgs);
mutex_unlock(&dangling_memcgs_mutex);
}
-#else
-static inline void memcg_dangling_free(struct mem_cgroup *memcg) {}
-static inline void memcg_dangling_add(struct mem_cgroup *memcg) {}
-#endif
static DEFINE_MUTEX(set_limit_mutex);
@@ -6312,6 +6311,41 @@ static int mem_cgroup_oom_control_write(struct cgroup *cgrp,
}
#ifdef CONFIG_MEMCG_KMEM
+static void memcg_vmpressure_shrink_dead(void)
+{
+ struct memcg_cache_params *params, *tmp;
+ struct kmem_cache *cachep;
+ struct mem_cgroup *memcg;
+
+ mutex_lock(&dangling_memcgs_mutex);
+ list_for_each_entry(memcg, &dangling_memcgs, dead) {
+ mutex_lock(&memcg->slab_caches_mutex);
+ /* The element may go away as an indirect result of shrink */
+ list_for_each_entry_safe(params, tmp,
+ &memcg->memcg_slab_caches, list) {
+ cachep = memcg_params_to_cache(params);
+ /*
+ * the cpu_hotplug lock is taken in kmem_cache_create
+ * outside the slab_caches_mutex manipulation. It will
+ * be taken by kmem_cache_shrink to flush the cache.
+ * So we need to drop the lock. It is all right because
+ * the lock only protects elements moving in and out the
+ * list.
+ */
+ mutex_unlock(&memcg->slab_caches_mutex);
+ kmem_cache_shrink(cachep);
+ mutex_lock(&memcg->slab_caches_mutex);
+ }
+ mutex_unlock(&memcg->slab_caches_mutex);
+ }
+ mutex_unlock(&dangling_memcgs_mutex);
+}
+
+static void memcg_register_kmem_events(struct cgroup *cont)
+{
+ vmpressure_register_kernel_event(cont, memcg_vmpressure_shrink_dead);
+}
+
static int memcg_init_kmem(struct mem_cgroup *memcg, struct cgroup_subsys *ss)
{
int ret;
@@ -6347,6 +6381,10 @@ static void kmem_cgroup_destroy(struct mem_cgroup *memcg)
}
}
#else
+static inline void memcg_register_kmem_events(struct cgroup *cont)
+{
+}
+
static int memcg_init_kmem(struct mem_cgroup *memcg, struct cgroup_subsys *ss)
{
return 0;
@@ -6732,8 +6770,10 @@ mem_cgroup_css_online(struct cgroup *cont)
struct mem_cgroup *memcg, *parent;
int error = 0;
- if (!cont->parent)
+ if (!cont->parent) {
+ memcg_register_kmem_events(cont);
return 0;
+ }
mutex_lock(&memcg_create_mutex);
memcg = mem_cgroup_from_cont(cont);
--
1.8.1.4
^ permalink raw reply related [flat|nested] 151+ messages in thread* [PATCH v6 31/31] memcg: reap dead memcgs upon global memory pressure.
@ 2013-05-12 18:13 ` Glauber Costa
0 siblings, 0 replies; 151+ messages in thread
From: Glauber Costa @ 2013-05-12 18:13 UTC (permalink / raw)
To: linux-mm
Cc: cgroups, Andrew Morton, Greg Thelen, kamezawa.hiroyu,
Michal Hocko, Johannes Weiner, linux-fsdevel, Dave Chinner,
Glauber Costa, Dave Chinner, Mel Gorman, Rik van Riel,
Hugh Dickins
When we delete kmem-enabled memcgs, they can still be zombieing
around for a while. The reason is that the objects may still be alive,
and we won't be able to delete them at destruction time.
The only entry point for that, though, are the shrinkers. The
shrinker interface, however, is not exactly tailored to our needs. It
could be a little bit better by using the API Dave Chinner proposed, but
it is still not ideal since we aren't really a count-and-scan event, but
more a one-off flush-all-you-can event that would have to abuse that
somehow.
Signed-off-by: Glauber Costa <glommer@openvz.org>
Cc: Dave Chinner <dchinner@redhat.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Rik van Riel <riel@redhat.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Michal Hocko <mhocko@suse.cz>
Cc: Hugh Dickins <hughd@google.com>
Cc: Kamezawa Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
---
mm/memcontrol.c | 52 ++++++++++++++++++++++++++++++++++++++++++++++------
1 file changed, 46 insertions(+), 6 deletions(-)
diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index 6f6a330..7006f03 100644
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -400,7 +400,6 @@ static size_t memcg_size(void)
nr_node_ids * sizeof(struct mem_cgroup_per_node);
}
-#ifdef CONFIG_MEMCG_DEBUG_ASYNC_DESTROY
static LIST_HEAD(dangling_memcgs);
static DEFINE_MUTEX(dangling_memcgs_mutex);
@@ -409,11 +408,14 @@ static inline void memcg_dangling_free(struct mem_cgroup *memcg)
mutex_lock(&dangling_memcgs_mutex);
list_del(&memcg->dead);
mutex_unlock(&dangling_memcgs_mutex);
+#ifdef CONFIG_MEMCG_DEBUG_ASYNC_DESTROY
free_pages((unsigned long)memcg->memcg_name, 0);
+#endif
}
static inline void memcg_dangling_add(struct mem_cgroup *memcg)
{
+#ifdef CONFIG_MEMCG_DEBUG_ASYNC_DESTROY
/*
* cgroup.c will do page-sized allocations most of the time,
* so we'll just follow the pattern. Also, __get_free_pages
@@ -439,15 +441,12 @@ static inline void memcg_dangling_add(struct mem_cgroup *memcg)
}
add_list:
+#endif
INIT_LIST_HEAD(&memcg->dead);
mutex_lock(&dangling_memcgs_mutex);
list_add(&memcg->dead, &dangling_memcgs);
mutex_unlock(&dangling_memcgs_mutex);
}
-#else
-static inline void memcg_dangling_free(struct mem_cgroup *memcg) {}
-static inline void memcg_dangling_add(struct mem_cgroup *memcg) {}
-#endif
static DEFINE_MUTEX(set_limit_mutex);
@@ -6312,6 +6311,41 @@ static int mem_cgroup_oom_control_write(struct cgroup *cgrp,
}
#ifdef CONFIG_MEMCG_KMEM
+static void memcg_vmpressure_shrink_dead(void)
+{
+ struct memcg_cache_params *params, *tmp;
+ struct kmem_cache *cachep;
+ struct mem_cgroup *memcg;
+
+ mutex_lock(&dangling_memcgs_mutex);
+ list_for_each_entry(memcg, &dangling_memcgs, dead) {
+ mutex_lock(&memcg->slab_caches_mutex);
+ /* The element may go away as an indirect result of shrink */
+ list_for_each_entry_safe(params, tmp,
+ &memcg->memcg_slab_caches, list) {
+ cachep = memcg_params_to_cache(params);
+ /*
+ * the cpu_hotplug lock is taken in kmem_cache_create
+ * outside the slab_caches_mutex manipulation. It will
+ * be taken by kmem_cache_shrink to flush the cache.
+ * So we need to drop the lock. It is all right because
+ * the lock only protects elements moving in and out the
+ * list.
+ */
+ mutex_unlock(&memcg->slab_caches_mutex);
+ kmem_cache_shrink(cachep);
+ mutex_lock(&memcg->slab_caches_mutex);
+ }
+ mutex_unlock(&memcg->slab_caches_mutex);
+ }
+ mutex_unlock(&dangling_memcgs_mutex);
+}
+
+static void memcg_register_kmem_events(struct cgroup *cont)
+{
+ vmpressure_register_kernel_event(cont, memcg_vmpressure_shrink_dead);
+}
+
static int memcg_init_kmem(struct mem_cgroup *memcg, struct cgroup_subsys *ss)
{
int ret;
@@ -6347,6 +6381,10 @@ static void kmem_cgroup_destroy(struct mem_cgroup *memcg)
}
}
#else
+static inline void memcg_register_kmem_events(struct cgroup *cont)
+{
+}
+
static int memcg_init_kmem(struct mem_cgroup *memcg, struct cgroup_subsys *ss)
{
return 0;
@@ -6732,8 +6770,10 @@ mem_cgroup_css_online(struct cgroup *cont)
struct mem_cgroup *memcg, *parent;
int error = 0;
- if (!cont->parent)
+ if (!cont->parent) {
+ memcg_register_kmem_events(cont);
return 0;
+ }
mutex_lock(&memcg_create_mutex);
memcg = mem_cgroup_from_cont(cont);
--
1.8.1.4
^ permalink raw reply related [flat|nested] 151+ messages in thread* [PATCH v6 31/31] memcg: reap dead memcgs upon global memory pressure.
@ 2013-05-12 18:13 ` Glauber Costa
0 siblings, 0 replies; 151+ messages in thread
From: Glauber Costa @ 2013-05-12 18:13 UTC (permalink / raw)
To: linux-mm
Cc: cgroups, Andrew Morton, Greg Thelen, kamezawa.hiroyu,
Michal Hocko, Johannes Weiner, linux-fsdevel, Dave Chinner,
Glauber Costa, Dave Chinner, Mel Gorman, Rik van Riel,
Hugh Dickins
When we delete kmem-enabled memcgs, they can still be zombieing
around for a while. The reason is that the objects may still be alive,
and we won't be able to delete them at destruction time.
The only entry point for that, though, are the shrinkers. The
shrinker interface, however, is not exactly tailored to our needs. It
could be a little bit better by using the API Dave Chinner proposed, but
it is still not ideal since we aren't really a count-and-scan event, but
more a one-off flush-all-you-can event that would have to abuse that
somehow.
Signed-off-by: Glauber Costa <glommer@openvz.org>
Cc: Dave Chinner <dchinner@redhat.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Rik van Riel <riel@redhat.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Michal Hocko <mhocko@suse.cz>
Cc: Hugh Dickins <hughd@google.com>
Cc: Kamezawa Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
---
mm/memcontrol.c | 52 ++++++++++++++++++++++++++++++++++++++++++++++------
1 file changed, 46 insertions(+), 6 deletions(-)
diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index 6f6a330..7006f03 100644
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -400,7 +400,6 @@ static size_t memcg_size(void)
nr_node_ids * sizeof(struct mem_cgroup_per_node);
}
-#ifdef CONFIG_MEMCG_DEBUG_ASYNC_DESTROY
static LIST_HEAD(dangling_memcgs);
static DEFINE_MUTEX(dangling_memcgs_mutex);
@@ -409,11 +408,14 @@ static inline void memcg_dangling_free(struct mem_cgroup *memcg)
mutex_lock(&dangling_memcgs_mutex);
list_del(&memcg->dead);
mutex_unlock(&dangling_memcgs_mutex);
+#ifdef CONFIG_MEMCG_DEBUG_ASYNC_DESTROY
free_pages((unsigned long)memcg->memcg_name, 0);
+#endif
}
static inline void memcg_dangling_add(struct mem_cgroup *memcg)
{
+#ifdef CONFIG_MEMCG_DEBUG_ASYNC_DESTROY
/*
* cgroup.c will do page-sized allocations most of the time,
* so we'll just follow the pattern. Also, __get_free_pages
@@ -439,15 +441,12 @@ static inline void memcg_dangling_add(struct mem_cgroup *memcg)
}
add_list:
+#endif
INIT_LIST_HEAD(&memcg->dead);
mutex_lock(&dangling_memcgs_mutex);
list_add(&memcg->dead, &dangling_memcgs);
mutex_unlock(&dangling_memcgs_mutex);
}
-#else
-static inline void memcg_dangling_free(struct mem_cgroup *memcg) {}
-static inline void memcg_dangling_add(struct mem_cgroup *memcg) {}
-#endif
static DEFINE_MUTEX(set_limit_mutex);
@@ -6312,6 +6311,41 @@ static int mem_cgroup_oom_control_write(struct cgroup *cgrp,
}
#ifdef CONFIG_MEMCG_KMEM
+static void memcg_vmpressure_shrink_dead(void)
+{
+ struct memcg_cache_params *params, *tmp;
+ struct kmem_cache *cachep;
+ struct mem_cgroup *memcg;
+
+ mutex_lock(&dangling_memcgs_mutex);
+ list_for_each_entry(memcg, &dangling_memcgs, dead) {
+ mutex_lock(&memcg->slab_caches_mutex);
+ /* The element may go away as an indirect result of shrink */
+ list_for_each_entry_safe(params, tmp,
+ &memcg->memcg_slab_caches, list) {
+ cachep = memcg_params_to_cache(params);
+ /*
+ * the cpu_hotplug lock is taken in kmem_cache_create
+ * outside the slab_caches_mutex manipulation. It will
+ * be taken by kmem_cache_shrink to flush the cache.
+ * So we need to drop the lock. It is all right because
+ * the lock only protects elements moving in and out the
+ * list.
+ */
+ mutex_unlock(&memcg->slab_caches_mutex);
+ kmem_cache_shrink(cachep);
+ mutex_lock(&memcg->slab_caches_mutex);
+ }
+ mutex_unlock(&memcg->slab_caches_mutex);
+ }
+ mutex_unlock(&dangling_memcgs_mutex);
+}
+
+static void memcg_register_kmem_events(struct cgroup *cont)
+{
+ vmpressure_register_kernel_event(cont, memcg_vmpressure_shrink_dead);
+}
+
static int memcg_init_kmem(struct mem_cgroup *memcg, struct cgroup_subsys *ss)
{
int ret;
@@ -6347,6 +6381,10 @@ static void kmem_cgroup_destroy(struct mem_cgroup *memcg)
}
}
#else
+static inline void memcg_register_kmem_events(struct cgroup *cont)
+{
+}
+
static int memcg_init_kmem(struct mem_cgroup *memcg, struct cgroup_subsys *ss)
{
return 0;
@@ -6732,8 +6770,10 @@ mem_cgroup_css_online(struct cgroup *cont)
struct mem_cgroup *memcg, *parent;
int error = 0;
- if (!cont->parent)
+ if (!cont->parent) {
+ memcg_register_kmem_events(cont);
return 0;
+ }
mutex_lock(&memcg_create_mutex);
memcg = mem_cgroup_from_cont(cont);
--
1.8.1.4
--
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^ permalink raw reply related [flat|nested] 151+ messages in thread
* Re: [PATCH v6 00/31] kmemcg shrinkers
2013-05-12 18:13 ` Glauber Costa
` (32 preceding siblings ...)
(?)
@ 2013-05-13 7:14 ` Dave Chinner
2013-05-13 7:21 ` Dave Chinner
2013-05-13 8:00 ` Glauber Costa
-1 siblings, 2 replies; 151+ messages in thread
From: Dave Chinner @ 2013-05-13 7:14 UTC (permalink / raw)
To: Glauber Costa
Cc: linux-mm, cgroups, Andrew Morton, Greg Thelen, kamezawa.hiroyu,
Michal Hocko, Johannes Weiner, linux-fsdevel
On Sun, May 12, 2013 at 10:13:21PM +0400, Glauber Costa wrote:
> Initial notes:
> ==============
>
> Mel, Dave, this is the last round of fixes I have for the series. The fixes are
> few, and I was mostly interested in getting this out based on an up2date tree
> so Dave can verify it. This should apply fine ontop of Friday's linux-next.
> Alternatively, please grab from branch "kmemcg-lru-shrinker" at:
>
> git://git.kernel.org/pub/scm/linux/kernel/git/glommer/memcg.git
>
> Main changes from *v5:
> * Rebased to linux-next, and fix the conflicts with the dcache.
> * Make sure LRU_RETRY only retry once
> * Prevent the bcache shrinker to scan the caches when disabled (by returning
> 0 in the count function)
> * Fix i915 return code when mutex cannot be acquired.
> * Only scan less-than-batch objects in memcg scenarios
Ok, this is behaving a *lot* better than v5 in terms of initial
balance and sustained behaviour under pure inode/dentry press
workloads. The previous version was all over the place, not to
mention unstable and prone to unrealted lockups in the block layer.
However, I'm not sure that the LRUness of reclaim is working
correctly at this point. When I switch from a write only workload to
a read-only workload (i.e. fsmark finishes and find starts), I see
this:
OBJS ACTIVE USE OBJ SIZE SLABS OBJ/SLAB CACHE SIZE NAME
1923037 1807201 93% 1.12K 68729 28 2199328K xfs_inode
1914624 490812 25% 0.22K 53184 36 425472K xfs_ili
Note the xfs_ili slab capacity - there's half a million objects
still in the cache, and they are only present on *dirty* inodes.
Now, the read-only workload is iterating through a cold-cache lookup
workload of 50 million inodes - at roughly 150,000/s. It's a
touch-once workload, so shoul dbe turning the cache over completely
every 10 seconds. However, in the time it's taken for me to explain
this:
OBJS ACTIVE USE OBJ SIZE SLABS OBJ/SLAB CACHE SIZE NAME
1954493 1764661 90% 1.12K 69831 28 2234592K xfs_inode
1643868 281962 17% 0.22K 45663 36 365304K xfs_ili
Only 200k xfs_ili's have been freed. So the rate of reclaim of them
is roughly 5k/s. Given the read-only nature of this workload, they
should be gone from the cache in a few seconds. Another indication
of problems here is the level of internal fragmentation of the
xfs_ili slab. They should cycle out of the cache in LRU manner, just
like inodes - the modify workload is a "touch once" workload as
well, so there should be no internal fragmentation of the slab
cache.
The stats I have of cache residency during the read-only part of the
workload looks really bad. No steady state is reached, while on 3.9
a perfect steady state is reached within seconds and maintained
until the workload changes. Part way through the read-only workload,
this happened:
[ 562.673080] sh (5007): dropped kernel caches: 3
[ 629.617303] lowmemorykiller: send sigkill to 3953 (winbindd), adj 0, size 195
[ 629.625499] lowmemorykiller: send sigkill to 3439 (pmcd), adj 0, size 158
And when the read-only workload finishes it's walk, I then start
another "touch once" workload that removes all the files. that
triggered:
[ 1002.183604] lowmemorykiller: send sigkill to 5827 (winbindd), adj 0, size 246
[ 1002.187822] lowmemorykiller: send sigkill to 3904 (winbindd), adj 0, size 134
Yeah, that stupid broken low memory killer is now kicking in,
killing random processes - last run it killed two of the rm
processes doing work, this time it killed winbindd and the PCP
collection daemon that I use for remote stats monitoring.
So, yeah, there's still some broken stuff in this patchset that
needs fixing. The script that I'm running to trigger these problems
is pretty basic - it's the same workload I've been using for the
past 3 years for measuring metadata performance of filesystems:
$ cat ./fsmark-50-test-xfs.sh
#!/bin/bash
sudo umount /mnt/scratch > /dev/null 2>&1
sudo mkfs.xfs -f $@ -l size=131072b,sunit=8 /dev/vdc
sudo mount -o nobarrier,logbsize=256k /dev/vdc /mnt/scratch
sudo chmod 777 /mnt/scratch
cd /home/dave/src/fs_mark-3.3/
time ./fs_mark -D 10000 -S0 -n 100000 -s 0 -L 63 \
-d /mnt/scratch/0 -d /mnt/scratch/1 \
-d /mnt/scratch/2 -d /mnt/scratch/3 \
-d /mnt/scratch/4 -d /mnt/scratch/5 \
-d /mnt/scratch/6 -d /mnt/scratch/7 \
| tee >(stats --trim-outliers | tail -1 1>&2)
sync
sleep 30
sync
echo walking files
sudo sh -c 'echo 3 > /proc/sys/vm/drop_caches'
time (
for d in /mnt/scratch/[0-9]* ; do
for i in $d/*; do
(
echo $i
find $i -ctime 1 > /dev/null
) > /dev/null 2>&1
done &
done
wait
)
echo removing files
for f in /mnt/scratch/* ; do time rm -rf $f & done
wait
$
It's running on an 8p, 4GB RAM, 4-node fake numa virtual machine
with a 100TB sparse image file being used for the test filesystem.
I'll spend some time over the next few days trying to work out what
is causing these issues....
Cheers,
Dave.
--
Dave Chinner
david@fromorbit.com
--
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^ permalink raw reply [flat|nested] 151+ messages in thread* Re: [PATCH v6 00/31] kmemcg shrinkers
2013-05-13 7:14 ` [PATCH v6 00/31] kmemcg shrinkers Dave Chinner
@ 2013-05-13 7:21 ` Dave Chinner
2013-05-13 8:00 ` Glauber Costa
1 sibling, 0 replies; 151+ messages in thread
From: Dave Chinner @ 2013-05-13 7:21 UTC (permalink / raw)
To: Glauber Costa
Cc: linux-mm, cgroups, Andrew Morton, Greg Thelen, kamezawa.hiroyu,
Michal Hocko, Johannes Weiner, linux-fsdevel
On Mon, May 13, 2013 at 05:14:00PM +1000, Dave Chinner wrote:
> On Sun, May 12, 2013 at 10:13:21PM +0400, Glauber Costa wrote:
> > Initial notes: ==============
> >
> > Mel, Dave, this is the last round of fixes I have for the
> > series. The fixes are few, and I was mostly interested in
> > getting this out based on an up2date tree so Dave can verify it.
> > This should apply fine ontop of Friday's linux-next.
> > Alternatively, please grab from branch "kmemcg-lru-shrinker" at:
> >
> > git://git.kernel.org/pub/scm/linux/kernel/git/glommer/memcg.git
> >
> > Main changes from *v5: * Rebased to linux-next, and fix the
> > conflicts with the dcache. * Make sure LRU_RETRY only retry
> > once * Prevent the bcache shrinker to scan the caches when
> > disabled (by returning 0 in the count function) * Fix i915
> > return code when mutex cannot be acquired. * Only scan
> > less-than-batch objects in memcg scenarios
>
> Ok, this is behaving a *lot* better than v5 in terms of initial
> balance and sustained behaviour under pure inode/dentry press
> workloads. The previous version was all over the place, not to
> mention unstable and prone to unrealted lockups in the block
> layer.
>
> However, I'm not sure that the LRUness of reclaim is working
> correctly at this point. When I switch from a write only workload
> to a read-only workload (i.e. fsmark finishes and find starts), I
> see this:
....
> So, yeah, there's still some broken stuff in this patchset that
> needs fixing. The script that I'm running to trigger these
> problems is pretty basic - it's the same workload I've been using
> for the past 3 years for measuring metadata performance of
> filesystems:
And unmounting an XFS filesystem after running this workload is
hanging from time to time due to a reference counting problem on a
buffer....
Cheers,
Dave.
--
Dave Chinner
david@fromorbit.com
--
To unsubscribe, send a message with 'unsubscribe linux-mm' in
the body to majordomo@kvack.org. For more info on Linux MM,
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^ permalink raw reply [flat|nested] 151+ messages in thread
* Re: [PATCH v6 00/31] kmemcg shrinkers
2013-05-13 7:14 ` [PATCH v6 00/31] kmemcg shrinkers Dave Chinner
2013-05-13 7:21 ` Dave Chinner
@ 2013-05-13 8:00 ` Glauber Costa
1 sibling, 0 replies; 151+ messages in thread
From: Glauber Costa @ 2013-05-13 8:00 UTC (permalink / raw)
To: Dave Chinner
Cc: Glauber Costa, linux-mm-Bw31MaZKKs3YtjvyW6yDsg,
cgroups-u79uwXL29TY76Z2rM5mHXA, Andrew Morton, Greg Thelen,
kamezawa.hiroyu-+CUm20s59erQFUHtdCDX3A, Michal Hocko,
Johannes Weiner, linux-fsdevel-u79uwXL29TY76Z2rM5mHXA
On 05/13/2013 11:14 AM, Dave Chinner wrote:
> On Sun, May 12, 2013 at 10:13:21PM +0400, Glauber Costa wrote:
>> Initial notes:
>> ==============
>>
>> Mel, Dave, this is the last round of fixes I have for the series. The fixes are
>> few, and I was mostly interested in getting this out based on an up2date tree
>> so Dave can verify it. This should apply fine ontop of Friday's linux-next.
>> Alternatively, please grab from branch "kmemcg-lru-shrinker" at:
>>
>> git://git.kernel.org/pub/scm/linux/kernel/git/glommer/memcg.git
>>
>> Main changes from *v5:
>> * Rebased to linux-next, and fix the conflicts with the dcache.
>> * Make sure LRU_RETRY only retry once
>> * Prevent the bcache shrinker to scan the caches when disabled (by returning
>> 0 in the count function)
>> * Fix i915 return code when mutex cannot be acquired.
>> * Only scan less-than-batch objects in memcg scenarios
>
> Ok, this is behaving a *lot* better than v5 in terms of initial
> balance and sustained behaviour under pure inode/dentry press
> workloads. The previous version was all over the place, not to
> mention unstable and prone to unrealted lockups in the block layer.
>
Good to hear. About the problems you are seeing, if possible, I think
it would beneficial to do what Mel did, and run a test workload without
the upper half of the patches, IOW, excluding memcg. It should at least
give us an indication about whether or not the problem lies in the way
we are handling the LRU list, or in any memcg adaptation problem.
> However, I'm not sure that the LRUness of reclaim is working
> correctly at this point. When I switch from a write only workload to
> a read-only workload (i.e. fsmark finishes and find starts), I see
> this:
>
> OBJS ACTIVE USE OBJ SIZE SLABS OBJ/SLAB CACHE SIZE NAME
> 1923037 1807201 93% 1.12K 68729 28 2199328K xfs_inode
> 1914624 490812 25% 0.22K 53184 36 425472K xfs_ili
>
> Note the xfs_ili slab capacity - there's half a million objects
> still in the cache, and they are only present on *dirty* inodes.
May a xfs-ignorant kernel hacker ask you what exactly xfs_ili is ?
> Now, the read-only workload is iterating through a cold-cache lookup
> workload of 50 million inodes - at roughly 150,000/s. It's a
> touch-once workload, so shoul dbe turning the cache over completely
> every 10 seconds. However, in the time it's taken for me to explain
> this:
>
> OBJS ACTIVE USE OBJ SIZE SLABS OBJ/SLAB CACHE SIZE NAME
> 1954493 1764661 90% 1.12K 69831 28 2234592K xfs_inode
> 1643868 281962 17% 0.22K 45663 36 365304K xfs_ili
>
> Only 200k xfs_ili's have been freed. So the rate of reclaim of them
> is roughly 5k/s. Given the read-only nature of this workload, they
> should be gone from the cache in a few seconds. Another indication
> of problems here is the level of internal fragmentation of the
> xfs_ili slab. They should cycle out of the cache in LRU manner, just
> like inodes - the modify workload is a "touch once" workload as
> well, so there should be no internal fragmentation of the slab
> cache.
>
Initial testing I have done indicates - although it does not undoubtly
prove - that the problem may be with dentries, not inodes. This is from
attempted bisecting at the postmark benchmark, but as you said yourself,
that kind of workload is not that bad any more, so this is unconclusive.
In particular, the behavior of lru_walk mimics very well
the inode behavior, but for dentries, we have the following situation:
Before the patchset:
====================
relock:
while (!list_empty(&sb->s_dentry_lru)) {
dentry = list_entry(sb->s_dentry_lru.prev,
struct dentry, d_lru);
if (!spin_trylock(&dentry->d_lock)) {
spin_unlock(&dcache_lru_lock);
cpu_relax(); <== doesn't modify count
goto relock;
}
if (dentry->d_flags & DCACHE_REFERENCED) {
dentry->d_flags &= ~DCACHE_REFERENCED;
list_move(&dentry->d_lru, &referenced);
spin_unlock(&dentry->d_lock); <== doesn't modify count
} else {
list_move_tail(&dentry->d_lru, &tmp);
dentry->d_flags |= DCACHE_SHRINK_LIST;
spin_unlock(&dentry->d_lock);
if (!--count)
break;
}
The code we have in list_lru.c will decrement nr_to_walk in every
situation except for LRU_RETRY.
There is also another problem I have just spotted while looking at this:
Differently from the experimental patch I sent Mel, the actual version
of LRU_RETRY does not actually flip the flag, meaning the behavior is
not what I envisioned.
You are seeing problems in the inode behavior, but since the dentry
cache may pin them, I believe it is possible that the change in behavior
in the dentry cache may drive the change in behavior in the inode cache,
by keeping inodes that should be freed, pinned. (So far, just a theory)
Comments welcome.
> The stats I have of cache residency during the read-only part of the
> workload looks really bad. No steady state is reached, while on 3.9
> a perfect steady state is reached within seconds and maintained
> until the workload changes. Part way through the read-only workload,
> this happened:
>
> [ 562.673080] sh (5007): dropped kernel caches: 3
> [ 629.617303] lowmemorykiller: send sigkill to 3953 (winbindd), adj 0, size 195
> [ 629.625499] lowmemorykiller: send sigkill to 3439 (pmcd), adj 0, size 158
>
> And when the read-only workload finishes it's walk, I then start
> another "touch once" workload that removes all the files. that
> triggered:
>
> [ 1002.183604] lowmemorykiller: send sigkill to 5827 (winbindd), adj 0, size 246
> [ 1002.187822] lowmemorykiller: send sigkill to 3904 (winbindd), adj 0, size 134
>
> Yeah, that stupid broken low memory killer is now kicking in,
> killing random processes - last run it killed two of the rm
> processes doing work, this time it killed winbindd and the PCP
> collection daemon that I use for remote stats monitoring.
>
> So, yeah, there's still some broken stuff in this patchset that
> needs fixing. The script that I'm running to trigger these problems
> is pretty basic - it's the same workload I've been using for the
> past 3 years for measuring metadata performance of filesystems:
>
I will try to run them myself, and I appreciate your diligence as well.
^ permalink raw reply [flat|nested] 151+ messages in thread* Re: [PATCH v6 00/31] kmemcg shrinkers
@ 2013-05-13 8:00 ` Glauber Costa
0 siblings, 0 replies; 151+ messages in thread
From: Glauber Costa @ 2013-05-13 8:00 UTC (permalink / raw)
To: Dave Chinner
Cc: Glauber Costa, linux-mm-Bw31MaZKKs3YtjvyW6yDsg,
cgroups-u79uwXL29TY76Z2rM5mHXA, Andrew Morton, Greg Thelen,
kamezawa.hiroyu-+CUm20s59erQFUHtdCDX3A, Michal Hocko,
Johannes Weiner, linux-fsdevel-u79uwXL29TY76Z2rM5mHXA
On 05/13/2013 11:14 AM, Dave Chinner wrote:
> On Sun, May 12, 2013 at 10:13:21PM +0400, Glauber Costa wrote:
>> Initial notes:
>> ==============
>>
>> Mel, Dave, this is the last round of fixes I have for the series. The fixes are
>> few, and I was mostly interested in getting this out based on an up2date tree
>> so Dave can verify it. This should apply fine ontop of Friday's linux-next.
>> Alternatively, please grab from branch "kmemcg-lru-shrinker" at:
>>
>> git://git.kernel.org/pub/scm/linux/kernel/git/glommer/memcg.git
>>
>> Main changes from *v5:
>> * Rebased to linux-next, and fix the conflicts with the dcache.
>> * Make sure LRU_RETRY only retry once
>> * Prevent the bcache shrinker to scan the caches when disabled (by returning
>> 0 in the count function)
>> * Fix i915 return code when mutex cannot be acquired.
>> * Only scan less-than-batch objects in memcg scenarios
>
> Ok, this is behaving a *lot* better than v5 in terms of initial
> balance and sustained behaviour under pure inode/dentry press
> workloads. The previous version was all over the place, not to
> mention unstable and prone to unrealted lockups in the block layer.
>
Good to hear. About the problems you are seeing, if possible, I think
it would beneficial to do what Mel did, and run a test workload without
the upper half of the patches, IOW, excluding memcg. It should at least
give us an indication about whether or not the problem lies in the way
we are handling the LRU list, or in any memcg adaptation problem.
> However, I'm not sure that the LRUness of reclaim is working
> correctly at this point. When I switch from a write only workload to
> a read-only workload (i.e. fsmark finishes and find starts), I see
> this:
>
> OBJS ACTIVE USE OBJ SIZE SLABS OBJ/SLAB CACHE SIZE NAME
> 1923037 1807201 93% 1.12K 68729 28 2199328K xfs_inode
> 1914624 490812 25% 0.22K 53184 36 425472K xfs_ili
>
> Note the xfs_ili slab capacity - there's half a million objects
> still in the cache, and they are only present on *dirty* inodes.
May a xfs-ignorant kernel hacker ask you what exactly xfs_ili is ?
> Now, the read-only workload is iterating through a cold-cache lookup
> workload of 50 million inodes - at roughly 150,000/s. It's a
> touch-once workload, so shoul dbe turning the cache over completely
> every 10 seconds. However, in the time it's taken for me to explain
> this:
>
> OBJS ACTIVE USE OBJ SIZE SLABS OBJ/SLAB CACHE SIZE NAME
> 1954493 1764661 90% 1.12K 69831 28 2234592K xfs_inode
> 1643868 281962 17% 0.22K 45663 36 365304K xfs_ili
>
> Only 200k xfs_ili's have been freed. So the rate of reclaim of them
> is roughly 5k/s. Given the read-only nature of this workload, they
> should be gone from the cache in a few seconds. Another indication
> of problems here is the level of internal fragmentation of the
> xfs_ili slab. They should cycle out of the cache in LRU manner, just
> like inodes - the modify workload is a "touch once" workload as
> well, so there should be no internal fragmentation of the slab
> cache.
>
Initial testing I have done indicates - although it does not undoubtly
prove - that the problem may be with dentries, not inodes. This is from
attempted bisecting at the postmark benchmark, but as you said yourself,
that kind of workload is not that bad any more, so this is unconclusive.
In particular, the behavior of lru_walk mimics very well
the inode behavior, but for dentries, we have the following situation:
Before the patchset:
====================
relock:
while (!list_empty(&sb->s_dentry_lru)) {
dentry = list_entry(sb->s_dentry_lru.prev,
struct dentry, d_lru);
if (!spin_trylock(&dentry->d_lock)) {
spin_unlock(&dcache_lru_lock);
cpu_relax(); <== doesn't modify count
goto relock;
}
if (dentry->d_flags & DCACHE_REFERENCED) {
dentry->d_flags &= ~DCACHE_REFERENCED;
list_move(&dentry->d_lru, &referenced);
spin_unlock(&dentry->d_lock); <== doesn't modify count
} else {
list_move_tail(&dentry->d_lru, &tmp);
dentry->d_flags |= DCACHE_SHRINK_LIST;
spin_unlock(&dentry->d_lock);
if (!--count)
break;
}
The code we have in list_lru.c will decrement nr_to_walk in every
situation except for LRU_RETRY.
There is also another problem I have just spotted while looking at this:
Differently from the experimental patch I sent Mel, the actual version
of LRU_RETRY does not actually flip the flag, meaning the behavior is
not what I envisioned.
You are seeing problems in the inode behavior, but since the dentry
cache may pin them, I believe it is possible that the change in behavior
in the dentry cache may drive the change in behavior in the inode cache,
by keeping inodes that should be freed, pinned. (So far, just a theory)
Comments welcome.
> The stats I have of cache residency during the read-only part of the
> workload looks really bad. No steady state is reached, while on 3.9
> a perfect steady state is reached within seconds and maintained
> until the workload changes. Part way through the read-only workload,
> this happened:
>
> [ 562.673080] sh (5007): dropped kernel caches: 3
> [ 629.617303] lowmemorykiller: send sigkill to 3953 (winbindd), adj 0, size 195
> [ 629.625499] lowmemorykiller: send sigkill to 3439 (pmcd), adj 0, size 158
>
> And when the read-only workload finishes it's walk, I then start
> another "touch once" workload that removes all the files. that
> triggered:
>
> [ 1002.183604] lowmemorykiller: send sigkill to 5827 (winbindd), adj 0, size 246
> [ 1002.187822] lowmemorykiller: send sigkill to 3904 (winbindd), adj 0, size 134
>
> Yeah, that stupid broken low memory killer is now kicking in,
> killing random processes - last run it killed two of the rm
> processes doing work, this time it killed winbindd and the PCP
> collection daemon that I use for remote stats monitoring.
>
> So, yeah, there's still some broken stuff in this patchset that
> needs fixing. The script that I'm running to trigger these problems
> is pretty basic - it's the same workload I've been using for the
> past 3 years for measuring metadata performance of filesystems:
>
I will try to run them myself, and I appreciate your diligence as well.
^ permalink raw reply [flat|nested] 151+ messages in thread* Re: [PATCH v6 00/31] kmemcg shrinkers
@ 2013-05-13 8:00 ` Glauber Costa
0 siblings, 0 replies; 151+ messages in thread
From: Glauber Costa @ 2013-05-13 8:00 UTC (permalink / raw)
To: Dave Chinner
Cc: Glauber Costa, linux-mm, cgroups, Andrew Morton, Greg Thelen,
kamezawa.hiroyu, Michal Hocko, Johannes Weiner, linux-fsdevel
On 05/13/2013 11:14 AM, Dave Chinner wrote:
> On Sun, May 12, 2013 at 10:13:21PM +0400, Glauber Costa wrote:
>> Initial notes:
>> ==============
>>
>> Mel, Dave, this is the last round of fixes I have for the series. The fixes are
>> few, and I was mostly interested in getting this out based on an up2date tree
>> so Dave can verify it. This should apply fine ontop of Friday's linux-next.
>> Alternatively, please grab from branch "kmemcg-lru-shrinker" at:
>>
>> git://git.kernel.org/pub/scm/linux/kernel/git/glommer/memcg.git
>>
>> Main changes from *v5:
>> * Rebased to linux-next, and fix the conflicts with the dcache.
>> * Make sure LRU_RETRY only retry once
>> * Prevent the bcache shrinker to scan the caches when disabled (by returning
>> 0 in the count function)
>> * Fix i915 return code when mutex cannot be acquired.
>> * Only scan less-than-batch objects in memcg scenarios
>
> Ok, this is behaving a *lot* better than v5 in terms of initial
> balance and sustained behaviour under pure inode/dentry press
> workloads. The previous version was all over the place, not to
> mention unstable and prone to unrealted lockups in the block layer.
>
Good to hear. About the problems you are seeing, if possible, I think
it would beneficial to do what Mel did, and run a test workload without
the upper half of the patches, IOW, excluding memcg. It should at least
give us an indication about whether or not the problem lies in the way
we are handling the LRU list, or in any memcg adaptation problem.
> However, I'm not sure that the LRUness of reclaim is working
> correctly at this point. When I switch from a write only workload to
> a read-only workload (i.e. fsmark finishes and find starts), I see
> this:
>
> OBJS ACTIVE USE OBJ SIZE SLABS OBJ/SLAB CACHE SIZE NAME
> 1923037 1807201 93% 1.12K 68729 28 2199328K xfs_inode
> 1914624 490812 25% 0.22K 53184 36 425472K xfs_ili
>
> Note the xfs_ili slab capacity - there's half a million objects
> still in the cache, and they are only present on *dirty* inodes.
May a xfs-ignorant kernel hacker ask you what exactly xfs_ili is ?
> Now, the read-only workload is iterating through a cold-cache lookup
> workload of 50 million inodes - at roughly 150,000/s. It's a
> touch-once workload, so shoul dbe turning the cache over completely
> every 10 seconds. However, in the time it's taken for me to explain
> this:
>
> OBJS ACTIVE USE OBJ SIZE SLABS OBJ/SLAB CACHE SIZE NAME
> 1954493 1764661 90% 1.12K 69831 28 2234592K xfs_inode
> 1643868 281962 17% 0.22K 45663 36 365304K xfs_ili
>
> Only 200k xfs_ili's have been freed. So the rate of reclaim of them
> is roughly 5k/s. Given the read-only nature of this workload, they
> should be gone from the cache in a few seconds. Another indication
> of problems here is the level of internal fragmentation of the
> xfs_ili slab. They should cycle out of the cache in LRU manner, just
> like inodes - the modify workload is a "touch once" workload as
> well, so there should be no internal fragmentation of the slab
> cache.
>
Initial testing I have done indicates - although it does not undoubtly
prove - that the problem may be with dentries, not inodes. This is from
attempted bisecting at the postmark benchmark, but as you said yourself,
that kind of workload is not that bad any more, so this is unconclusive.
In particular, the behavior of lru_walk mimics very well
the inode behavior, but for dentries, we have the following situation:
Before the patchset:
====================
relock:
while (!list_empty(&sb->s_dentry_lru)) {
dentry = list_entry(sb->s_dentry_lru.prev,
struct dentry, d_lru);
if (!spin_trylock(&dentry->d_lock)) {
spin_unlock(&dcache_lru_lock);
cpu_relax(); <== doesn't modify count
goto relock;
}
if (dentry->d_flags & DCACHE_REFERENCED) {
dentry->d_flags &= ~DCACHE_REFERENCED;
list_move(&dentry->d_lru, &referenced);
spin_unlock(&dentry->d_lock); <== doesn't modify count
} else {
list_move_tail(&dentry->d_lru, &tmp);
dentry->d_flags |= DCACHE_SHRINK_LIST;
spin_unlock(&dentry->d_lock);
if (!--count)
break;
}
The code we have in list_lru.c will decrement nr_to_walk in every
situation except for LRU_RETRY.
There is also another problem I have just spotted while looking at this:
Differently from the experimental patch I sent Mel, the actual version
of LRU_RETRY does not actually flip the flag, meaning the behavior is
not what I envisioned.
You are seeing problems in the inode behavior, but since the dentry
cache may pin them, I believe it is possible that the change in behavior
in the dentry cache may drive the change in behavior in the inode cache,
by keeping inodes that should be freed, pinned. (So far, just a theory)
Comments welcome.
> The stats I have of cache residency during the read-only part of the
> workload looks really bad. No steady state is reached, while on 3.9
> a perfect steady state is reached within seconds and maintained
> until the workload changes. Part way through the read-only workload,
> this happened:
>
> [ 562.673080] sh (5007): dropped kernel caches: 3
> [ 629.617303] lowmemorykiller: send sigkill to 3953 (winbindd), adj 0, size 195
> [ 629.625499] lowmemorykiller: send sigkill to 3439 (pmcd), adj 0, size 158
>
> And when the read-only workload finishes it's walk, I then start
> another "touch once" workload that removes all the files. that
> triggered:
>
> [ 1002.183604] lowmemorykiller: send sigkill to 5827 (winbindd), adj 0, size 246
> [ 1002.187822] lowmemorykiller: send sigkill to 3904 (winbindd), adj 0, size 134
>
> Yeah, that stupid broken low memory killer is now kicking in,
> killing random processes - last run it killed two of the rm
> processes doing work, this time it killed winbindd and the PCP
> collection daemon that I use for remote stats monitoring.
>
> So, yeah, there's still some broken stuff in this patchset that
> needs fixing. The script that I'm running to trigger these problems
> is pretty basic - it's the same workload I've been using for the
> past 3 years for measuring metadata performance of filesystems:
>
I will try to run them myself, and I appreciate your diligence as well.
--
To unsubscribe, send a message with 'unsubscribe linux-mm' in
the body to majordomo@kvack.org. For more info on Linux MM,
see: http://www.linux-mm.org/ .
Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a>
^ permalink raw reply [flat|nested] 151+ messages in thread[parent not found: <51909D84.7040800-bzQdu9zFT3WakBO8gow8eQ@public.gmane.org>]
* Re: [PATCH v6 00/31] kmemcg shrinkers
2013-05-13 8:00 ` Glauber Costa
@ 2013-05-14 1:48 ` Dave Chinner
-1 siblings, 0 replies; 151+ messages in thread
From: Dave Chinner @ 2013-05-14 1:48 UTC (permalink / raw)
To: Glauber Costa
Cc: Glauber Costa, linux-mm-Bw31MaZKKs3YtjvyW6yDsg,
cgroups-u79uwXL29TY76Z2rM5mHXA, Andrew Morton, Greg Thelen,
kamezawa.hiroyu-+CUm20s59erQFUHtdCDX3A, Michal Hocko,
Johannes Weiner, linux-fsdevel-u79uwXL29TY76Z2rM5mHXA
On Mon, May 13, 2013 at 12:00:04PM +0400, Glauber Costa wrote:
> On 05/13/2013 11:14 AM, Dave Chinner wrote:
> > On Sun, May 12, 2013 at 10:13:21PM +0400, Glauber Costa wrote:
> >> Initial notes:
> >> ==============
> >>
> >> Mel, Dave, this is the last round of fixes I have for the series. The fixes are
> >> few, and I was mostly interested in getting this out based on an up2date tree
> >> so Dave can verify it. This should apply fine ontop of Friday's linux-next.
> >> Alternatively, please grab from branch "kmemcg-lru-shrinker" at:
> >>
> >> git://git.kernel.org/pub/scm/linux/kernel/git/glommer/memcg.git
> >>
> >> Main changes from *v5:
> >> * Rebased to linux-next, and fix the conflicts with the dcache.
> >> * Make sure LRU_RETRY only retry once
> >> * Prevent the bcache shrinker to scan the caches when disabled (by returning
> >> 0 in the count function)
> >> * Fix i915 return code when mutex cannot be acquired.
> >> * Only scan less-than-batch objects in memcg scenarios
> >
> > Ok, this is behaving a *lot* better than v5 in terms of initial
> > balance and sustained behaviour under pure inode/dentry press
> > workloads. The previous version was all over the place, not to
> > mention unstable and prone to unrealted lockups in the block layer.
> >
>
> Good to hear. About the problems you are seeing, if possible, I think
> it would beneficial to do what Mel did, and run a test workload without
> the upper half of the patches, IOW, excluding memcg. It should at least
> give us an indication about whether or not the problem lies in the way
> we are handling the LRU list, or in any memcg adaptation problem.
>
> > However, I'm not sure that the LRUness of reclaim is working
> > correctly at this point. When I switch from a write only workload to
> > a read-only workload (i.e. fsmark finishes and find starts), I see
> > this:
> >
> > OBJS ACTIVE USE OBJ SIZE SLABS OBJ/SLAB CACHE SIZE NAME
> > 1923037 1807201 93% 1.12K 68729 28 2199328K xfs_inode
> > 1914624 490812 25% 0.22K 53184 36 425472K xfs_ili
> >
> > Note the xfs_ili slab capacity - there's half a million objects
> > still in the cache, and they are only present on *dirty* inodes.
>
> May a xfs-ignorant kernel hacker ask you what exactly xfs_ili is ?
struct xfs_inode_log_item.
It's the structure used to track the inode through the journalling
subsystem, and it's only allocated when the inode is first modified.
The embedded xfs_log_item is the abstraction used throughout the
core transaction and journalling subsystems - every dirty metadata
object in XFS has a xfs_log_item attached to it in some way.
> > Now, the read-only workload is iterating through a cold-cache lookup
> > workload of 50 million inodes - at roughly 150,000/s. It's a
> > touch-once workload, so shoul dbe turning the cache over completely
> > every 10 seconds. However, in the time it's taken for me to explain
> > this:
> >
> > OBJS ACTIVE USE OBJ SIZE SLABS OBJ/SLAB CACHE SIZE NAME
> > 1954493 1764661 90% 1.12K 69831 28 2234592K xfs_inode
> > 1643868 281962 17% 0.22K 45663 36 365304K xfs_ili
> >
> > Only 200k xfs_ili's have been freed. So the rate of reclaim of them
> > is roughly 5k/s. Given the read-only nature of this workload, they
> > should be gone from the cache in a few seconds. Another indication
> > of problems here is the level of internal fragmentation of the
> > xfs_ili slab. They should cycle out of the cache in LRU manner, just
> > like inodes - the modify workload is a "touch once" workload as
> > well, so there should be no internal fragmentation of the slab
> > cache.
> >
>
> Initial testing I have done indicates - although it does not undoubtly
> prove - that the problem may be with dentries, not inodes
That tallies with the stats I'm seeing showing a significant
difference in the balance of allocated vs "free" dentries. On a 3.9 kernel,
the is little difference between them - dentries move quickly to the
LRU and are considered free, while this patchset starts the same
they quickly diverge, with the free count dropping well away from
the allocated count.
....
> You are seeing problems in the inode behavior, but since the dentry
> cache may pin them, I believe it is possible that the change in behavior
> in the dentry cache may drive the change in behavior in the inode cache,
> by keeping inodes that should be freed, pinned. (So far, just a theory)
Yup, that's the theory I'm working to given the inode used vs free
count differences reflect the differences in the dentry behaviour...
Cheers,
Dave.
--
Dave Chinner
david-FqsqvQoI3Ljby3iVrkZq2A@public.gmane.org
^ permalink raw reply [flat|nested] 151+ messages in thread
* Re: [PATCH v6 00/31] kmemcg shrinkers
@ 2013-05-14 1:48 ` Dave Chinner
0 siblings, 0 replies; 151+ messages in thread
From: Dave Chinner @ 2013-05-14 1:48 UTC (permalink / raw)
To: Glauber Costa
Cc: Glauber Costa, linux-mm, cgroups, Andrew Morton, Greg Thelen,
kamezawa.hiroyu, Michal Hocko, Johannes Weiner, linux-fsdevel
On Mon, May 13, 2013 at 12:00:04PM +0400, Glauber Costa wrote:
> On 05/13/2013 11:14 AM, Dave Chinner wrote:
> > On Sun, May 12, 2013 at 10:13:21PM +0400, Glauber Costa wrote:
> >> Initial notes:
> >> ==============
> >>
> >> Mel, Dave, this is the last round of fixes I have for the series. The fixes are
> >> few, and I was mostly interested in getting this out based on an up2date tree
> >> so Dave can verify it. This should apply fine ontop of Friday's linux-next.
> >> Alternatively, please grab from branch "kmemcg-lru-shrinker" at:
> >>
> >> git://git.kernel.org/pub/scm/linux/kernel/git/glommer/memcg.git
> >>
> >> Main changes from *v5:
> >> * Rebased to linux-next, and fix the conflicts with the dcache.
> >> * Make sure LRU_RETRY only retry once
> >> * Prevent the bcache shrinker to scan the caches when disabled (by returning
> >> 0 in the count function)
> >> * Fix i915 return code when mutex cannot be acquired.
> >> * Only scan less-than-batch objects in memcg scenarios
> >
> > Ok, this is behaving a *lot* better than v5 in terms of initial
> > balance and sustained behaviour under pure inode/dentry press
> > workloads. The previous version was all over the place, not to
> > mention unstable and prone to unrealted lockups in the block layer.
> >
>
> Good to hear. About the problems you are seeing, if possible, I think
> it would beneficial to do what Mel did, and run a test workload without
> the upper half of the patches, IOW, excluding memcg. It should at least
> give us an indication about whether or not the problem lies in the way
> we are handling the LRU list, or in any memcg adaptation problem.
>
> > However, I'm not sure that the LRUness of reclaim is working
> > correctly at this point. When I switch from a write only workload to
> > a read-only workload (i.e. fsmark finishes and find starts), I see
> > this:
> >
> > OBJS ACTIVE USE OBJ SIZE SLABS OBJ/SLAB CACHE SIZE NAME
> > 1923037 1807201 93% 1.12K 68729 28 2199328K xfs_inode
> > 1914624 490812 25% 0.22K 53184 36 425472K xfs_ili
> >
> > Note the xfs_ili slab capacity - there's half a million objects
> > still in the cache, and they are only present on *dirty* inodes.
>
> May a xfs-ignorant kernel hacker ask you what exactly xfs_ili is ?
struct xfs_inode_log_item.
It's the structure used to track the inode through the journalling
subsystem, and it's only allocated when the inode is first modified.
The embedded xfs_log_item is the abstraction used throughout the
core transaction and journalling subsystems - every dirty metadata
object in XFS has a xfs_log_item attached to it in some way.
> > Now, the read-only workload is iterating through a cold-cache lookup
> > workload of 50 million inodes - at roughly 150,000/s. It's a
> > touch-once workload, so shoul dbe turning the cache over completely
> > every 10 seconds. However, in the time it's taken for me to explain
> > this:
> >
> > OBJS ACTIVE USE OBJ SIZE SLABS OBJ/SLAB CACHE SIZE NAME
> > 1954493 1764661 90% 1.12K 69831 28 2234592K xfs_inode
> > 1643868 281962 17% 0.22K 45663 36 365304K xfs_ili
> >
> > Only 200k xfs_ili's have been freed. So the rate of reclaim of them
> > is roughly 5k/s. Given the read-only nature of this workload, they
> > should be gone from the cache in a few seconds. Another indication
> > of problems here is the level of internal fragmentation of the
> > xfs_ili slab. They should cycle out of the cache in LRU manner, just
> > like inodes - the modify workload is a "touch once" workload as
> > well, so there should be no internal fragmentation of the slab
> > cache.
> >
>
> Initial testing I have done indicates - although it does not undoubtly
> prove - that the problem may be with dentries, not inodes
That tallies with the stats I'm seeing showing a significant
difference in the balance of allocated vs "free" dentries. On a 3.9 kernel,
the is little difference between them - dentries move quickly to the
LRU and are considered free, while this patchset starts the same
they quickly diverge, with the free count dropping well away from
the allocated count.
....
> You are seeing problems in the inode behavior, but since the dentry
> cache may pin them, I believe it is possible that the change in behavior
> in the dentry cache may drive the change in behavior in the inode cache,
> by keeping inodes that should be freed, pinned. (So far, just a theory)
Yup, that's the theory I'm working to given the inode used vs free
count differences reflect the differences in the dentry behaviour...
Cheers,
Dave.
--
Dave Chinner
david@fromorbit.com
--
To unsubscribe, send a message with 'unsubscribe linux-mm' in
the body to majordomo@kvack.org. For more info on Linux MM,
see: http://www.linux-mm.org/ .
Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a>
^ permalink raw reply [flat|nested] 151+ messages in thread
* Re: [PATCH v6 00/31] kmemcg shrinkers
2013-05-14 1:48 ` Dave Chinner
(?)
@ 2013-05-14 5:22 ` Dave Chinner
2013-05-14 5:45 ` Dave Chinner
2013-05-14 7:38 ` Glauber Costa
-1 siblings, 2 replies; 151+ messages in thread
From: Dave Chinner @ 2013-05-14 5:22 UTC (permalink / raw)
To: Glauber Costa
Cc: Glauber Costa, linux-mm, cgroups, Andrew Morton, Greg Thelen,
kamezawa.hiroyu, Michal Hocko, Johannes Weiner, linux-fsdevel
On Tue, May 14, 2013 at 11:48:05AM +1000, Dave Chinner wrote:
> On Mon, May 13, 2013 at 12:00:04PM +0400, Glauber Costa wrote:
> > On 05/13/2013 11:14 AM, Dave Chinner wrote:
> > > Now, the read-only workload is iterating through a cold-cache lookup
> > > workload of 50 million inodes - at roughly 150,000/s. It's a
> > > touch-once workload, so shoul dbe turning the cache over completely
> > > every 10 seconds. However, in the time it's taken for me to explain
> > > this:
> > >
> > > OBJS ACTIVE USE OBJ SIZE SLABS OBJ/SLAB CACHE SIZE NAME
> > > 1954493 1764661 90% 1.12K 69831 28 2234592K xfs_inode
> > > 1643868 281962 17% 0.22K 45663 36 365304K xfs_ili
> > >
> > > Only 200k xfs_ili's have been freed. So the rate of reclaim of them
> > > is roughly 5k/s. Given the read-only nature of this workload, they
> > > should be gone from the cache in a few seconds. Another indication
> > > of problems here is the level of internal fragmentation of the
> > > xfs_ili slab. They should cycle out of the cache in LRU manner, just
> > > like inodes - the modify workload is a "touch once" workload as
> > > well, so there should be no internal fragmentation of the slab
> > > cache.
> > >
> >
> > Initial testing I have done indicates - although it does not undoubtly
> > prove - that the problem may be with dentries, not inodes
>
> That tallies with the stats I'm seeing showing a significant
> difference in the balance of allocated vs "free" dentries. On a 3.9 kernel,
> the is little difference between them - dentries move quickly to the
> LRU and are considered free, while this patchset starts the same
> they quickly diverge, with the free count dropping well away from
> the allocated count.
So, there's something early on going wrong in the patch set. This
is from a tree at this patch in the series:
803d32a inode: convert inode lru list to generic lru list code.
Which is before the dentry cache is converted to the new LRU list
code. So there's something wrong either in the underlying linux-next
OBJS ACTIVE USE OBJ SIZE SLABS OBJ/SLAB CACHE SIZE NAME
1894912 1610470 84% 0.06K 29608 64 118432K kmalloc-64
1894738 1660467 87% 1.12K 67696 28 2166272K xfs_inode
1892232 1633839 86% 0.22K 52562 36 420496K xfs_ili
1887962 1614100 85% 0.21K 51026 37 408208K dentry
562744 562191 99% 0.55K 20098 28 321568K radix_tree_node
And:
$ cat /proc/sys/fs/dentry-state
1702143 96055 45 0 0 0
$
Which reflects this:
struct dentry_stat_t {
int nr_dentry;
int nr_unused;
int age_limit; /* age in seconds */
int want_pages; /* pages requested by system */
int dummy[2];
};
Which basicaly says we have 1.7 million allocated dentrys, but only
100k dentries on the LRU lists. So there's something wrong either
in the underlying linux-next tree, or the initial 3 dentry cache
patches are now buggy.
<revert back to linux-next tree base>
<groan>
test-4 login: [ 71.106361] XFS (vdc): Mounting Filesystem
[ 71.130097] XFS (vdc): Ending clean mount
[ 91.980679] fs_mark (4394) used greatest stack depth: 3048 bytes left
[ 92.286173] fs_mark (4396) used greatest stack depth: 3032 bytes left
[ 92.340949] fs_mark (4397) used greatest stack depth: 3024 bytes left
[ 120.162200] lowmemorykiller: send sigkill to 2948 (rsyslogd), adj 0, size 209
[ 122.518167] fs_mark (4434) used greatest stack depth: 2952 bytes left
[ 127.213331] lowmemorykiller: send sigkill to 3421 (pmcd), adj 0, size 202
[ 165.402109] lowmemorykiller: send sigkill to 3302 (cron), adj 0, size 94
[ 165.435809] lowmemorykiller: send sigkill to 1 (init), adj 0, size 87
[ 169.003846] fs_mark (4484) used greatest stack depth: 2720 bytes left
[ 189.093392] lowmemorykiller: send sigkill to 1 (init), adj 0, size 86
[ 195.153252] lowmemorykiller: send sigkill to 1 (init), adj 0, size 80
[ 209.016457] lowmemorykiller: send sigkill to 1 (init), adj 0, size 86
[ 219.431805] lowmemorykiller: send sigkill to 1 (init), adj 0, size 86
So, the lowmemory killer is fucked up in the linux-next tree, not by
this patchset. Before it killed pmcd, it looked like the dentry
counters were running as per 3.9.0. Reboot, try again:
[ 79.304611] lowmemorykiller: send sigkill to 4593 (fs_mark), adj 0, size 2121
[ 131.334226] lowmemorykiller: send sigkill to 4647 (find), adj 0, size 7658
[ 131.762285] lowmemorykiller: send sigkill to 4645 (find), adj 0, size 7658
[ 131.858137] lowmemorykiller: send sigkill to 4653 (find), adj 0, size 7658
[ 131.982366] lowmemorykiller: send sigkill to 4655 (find), adj 0, size 7658
[ 132.455610] lowmemorykiller: send sigkill to 4657 (find), adj 0, size 7658
[ 132.983835] lowmemorykiller: send sigkill to 4659 (find), adj 0, size 7658
[ 133.136868] lowmemorykiller: send sigkill to 4661 (find), adj 0, size 7658
[ 133.762004] lowmemorykiller: send sigkill to 4665 (find), adj 0, size 7658
[ 139.666345] lowmemorykiller: send sigkill to 4685 (rm), adj 0, size 8195
[ 142.964679] lowmemorykiller: send sigkill to 4691 (rm), adj 0, size 8195
[ 154.573456] lowmemorykiller: send sigkill to 4686 (rm), adj 0, size 8293
Right, I'm turning that crap off.
Ok, that's more like what I expect:
$ cat /proc/sys/fs/dentry-state
937104 929728 45 0 0 0
$ cat /proc/sys/fs/dentry-state
1124254 1116881 45 0 0 0
$ cat /proc/sys/fs/dentry-state
1256143 1248768 45 0 0 0
$ cat /proc/sys/fs/dentry-state
761321 753937 45 0 0 0
$ cat /proc/sys/fs/dentry-state
177308 169925 45 0 0 0
$ cat /proc/sys/fs/dentry-state
614756 607371 45 0 0 0
$ cat /proc/sys/fs/dentry-state
848316 840932 45 0 0 0
unused tracks allocated very closely.
So it's patch 4 that is broken:
dcache: remove dentries from LRU before putting on dispose list
I've found the problem. dentry_kill() returns the current dentry if
it cannot lock the dentry->d_inode or the dentry->d_parent, and when
that happens try_prune_one_dentry() silently fails to prune the
dentry. But, at this point, we've already removed the dentry from
both the LRU and the shrink list, and so it gets dropped on the
floor.
patch 4 needs some work:
- fix the above leak shrink list leak
- fix the scope of the sb locking inside shrink_dcache_sb()
- remove the readditional of dentry_lru_prune().
The reworked patch below does this.
Cheers,
Dave.
--
Dave Chinner
david@fromorbit.com
dcache: remove dentries from LRU before putting on dispose list
From: Dave Chinner <dchinner@redhat.com>
One of the big problems with modifying the way the dcache shrinker
and LRU implementation works is that the LRU is abused in several
ways. One of these is shrink_dentry_list().
Basically, we can move a dentry off the LRU onto a different list
without doing any accounting changes, and then use dentry_lru_prune()
to remove it from what-ever list it is now on to do the LRU
accounting at that point.
This makes it -really hard- to change the LRU implementation. The
use of the per-sb LRU lock serialises movement of the dentries
between the different lists and the removal of them, and this is the
only reason that it works. If we want to break up the dentry LRU
lock and lists into, say, per-node lists, we remove the only
serialisation that allows this lru list/dispose list abuse to work.
To make this work effectively, the dispose list has to be isolated
from the LRU list - dentries have to be removed from the LRU
*before* being placed on the dispose list. This means that the LRU
accounting and isolation is completed before disposal is started,
and that means we can change the LRU implementation freely in
future.
This means that dentries *must* be marked with DCACHE_SHRINK_LIST
when they are placed on the dispose list so that we don't think that
parent dentries found in try_prune_one_dentry() are on the LRU when
the are actually on the dispose list. This would result in
accounting the dentry to the LRU a second time. Hence
dentry_lru_del() has to handle the DCACHE_SHRINK_LIST case
differently because the dentry isn't on the LRU list.
[ v2: don't decrement nr unused twice, spotted by Sha Zhengju ]
[ v7: (dchinner)
- shrink list leaks dentries when inode/parent can't be locked in
dentry_kill().
- fix the scope of the sb locking inside shrink_dcache_sb()
- remove the readdition of dentry_lru_prune(). ]
Signed-off-by: Dave Chinner <dchinner@redhat.com>
---
fs/dcache.c | 90 ++++++++++++++++++++++++++++++++++++++++++++---------------
1 file changed, 68 insertions(+), 22 deletions(-)
diff --git a/fs/dcache.c b/fs/dcache.c
index 795c15d..edaf462 100644
--- a/fs/dcache.c
+++ b/fs/dcache.c
@@ -315,7 +315,7 @@ static void dentry_unlink_inode(struct dentry * dentry)
}
/*
- * dentry_lru_(add|del|prune|move_tail) must be called with d_lock held.
+ * dentry_lru_(add|del|move_list) must be called with d_lock held.
*/
static void dentry_lru_add(struct dentry *dentry)
{
@@ -341,7 +341,8 @@ static void __dentry_lru_del(struct dentry *dentry)
*/
static void dentry_lru_del(struct dentry *dentry)
{
- if (!list_empty(&dentry->d_lru)) {
+ if (!list_empty(&dentry->d_lru) &&
+ !(dentry->d_flags & DCACHE_SHRINK_LIST)) {
spin_lock(&dentry->d_sb->s_dentry_lru_lock);
__dentry_lru_del(dentry);
spin_unlock(&dentry->d_sb->s_dentry_lru_lock);
@@ -350,13 +351,15 @@ static void dentry_lru_del(struct dentry *dentry)
static void dentry_lru_move_list(struct dentry *dentry, struct list_head *list)
{
+ BUG_ON(dentry->d_flags & DCACHE_SHRINK_LIST);
+
spin_lock(&dentry->d_sb->s_dentry_lru_lock);
if (list_empty(&dentry->d_lru)) {
list_add_tail(&dentry->d_lru, list);
- dentry->d_sb->s_nr_dentry_unused++;
- this_cpu_inc(nr_dentry_unused);
} else {
list_move_tail(&dentry->d_lru, list);
+ dentry->d_sb->s_nr_dentry_unused--;
+ this_cpu_dec(nr_dentry_unused);
}
spin_unlock(&dentry->d_sb->s_dentry_lru_lock);
}
@@ -454,7 +457,8 @@ EXPORT_SYMBOL(d_drop);
* If ref is non-zero, then decrement the refcount too.
* Returns dentry requiring refcount drop, or NULL if we're done.
*/
-static inline struct dentry *dentry_kill(struct dentry *dentry, int ref)
+static inline struct dentry *
+dentry_kill(struct dentry *dentry, int ref, int unlock_on_failure)
__releases(dentry->d_lock)
{
struct inode *inode;
@@ -463,8 +467,10 @@ static inline struct dentry *dentry_kill(struct dentry *dentry, int ref)
inode = dentry->d_inode;
if (inode && !spin_trylock(&inode->i_lock)) {
relock:
- spin_unlock(&dentry->d_lock);
- cpu_relax();
+ if (unlock_on_failure) {
+ spin_unlock(&dentry->d_lock);
+ cpu_relax();
+ }
return dentry; /* try again with same dentry */
}
if (IS_ROOT(dentry))
@@ -551,7 +557,7 @@ repeat:
return;
kill_it:
- dentry = dentry_kill(dentry, 1);
+ dentry = dentry_kill(dentry, 1, 1);
if (dentry)
goto repeat;
}
@@ -750,12 +756,12 @@ EXPORT_SYMBOL(d_prune_aliases);
*
* This may fail if locks cannot be acquired no problem, just try again.
*/
-static void try_prune_one_dentry(struct dentry *dentry)
+static struct dentry * try_prune_one_dentry(struct dentry *dentry)
__releases(dentry->d_lock)
{
struct dentry *parent;
- parent = dentry_kill(dentry, 0);
+ parent = dentry_kill(dentry, 0, 0);
/*
* If dentry_kill returns NULL, we have nothing more to do.
* if it returns the same dentry, trylocks failed. In either
@@ -767,9 +773,9 @@ static void try_prune_one_dentry(struct dentry *dentry)
* fragmentation.
*/
if (!parent)
- return;
+ return NULL;
if (parent == dentry)
- return;
+ return dentry;
/* Prune ancestors. */
dentry = parent;
@@ -778,9 +784,9 @@ static void try_prune_one_dentry(struct dentry *dentry)
if (dentry->d_count > 1) {
dentry->d_count--;
spin_unlock(&dentry->d_lock);
- return;
+ return NULL;
}
- dentry = dentry_kill(dentry, 1);
+ dentry = dentry_kill(dentry, 1, 1);
}
}
@@ -800,21 +806,31 @@ static void shrink_dentry_list(struct list_head *list)
}
/*
+ * The dispose list is isolated and dentries are not accounted
+ * to the LRU here, so we can simply remove it from the list
+ * here regardless of whether it is referenced or not.
+ */
+ list_del_init(&dentry->d_lru);
+ dentry->d_flags &= ~DCACHE_SHRINK_LIST;
+
+ /*
* We found an inuse dentry which was not removed from
- * the LRU because of laziness during lookup. Do not free
- * it - just keep it off the LRU list.
+ * the LRU because of laziness during lookup. Do not free it.
*/
if (dentry->d_count) {
- dentry_lru_del(dentry);
spin_unlock(&dentry->d_lock);
continue;
}
-
rcu_read_unlock();
- try_prune_one_dentry(dentry);
+ dentry = try_prune_one_dentry(dentry);
rcu_read_lock();
+ if (dentry) {
+ dentry->d_flags |= DCACHE_SHRINK_LIST;
+ list_add(&dentry->d_lru, list);
+ spin_unlock(&dentry->d_lock);
+ }
}
rcu_read_unlock();
}
@@ -855,8 +871,10 @@ relock:
list_move(&dentry->d_lru, &referenced);
spin_unlock(&dentry->d_lock);
} else {
- list_move_tail(&dentry->d_lru, &tmp);
+ list_move(&dentry->d_lru, &tmp);
dentry->d_flags |= DCACHE_SHRINK_LIST;
+ this_cpu_dec(nr_dentry_unused);
+ sb->s_nr_dentry_unused--;
spin_unlock(&dentry->d_lock);
if (!--count)
break;
@@ -870,6 +888,27 @@ relock:
shrink_dentry_list(&tmp);
}
+/*
+ * Mark all the dentries as on being the dispose list so we don't think they are
+ * still on the LRU if we try to kill them from ascending the parent chain in
+ * try_prune_one_dentry() rather than directly from the dispose list.
+ */
+static void
+shrink_dcache_list(
+ struct list_head *dispose)
+{
+ struct dentry *dentry;
+
+ rcu_read_lock();
+ list_for_each_entry_rcu(dentry, dispose, d_lru) {
+ spin_lock(&dentry->d_lock);
+ dentry->d_flags |= DCACHE_SHRINK_LIST;
+ spin_unlock(&dentry->d_lock);
+ }
+ rcu_read_unlock();
+ shrink_dentry_list(dispose);
+}
+
/**
* shrink_dcache_sb - shrink dcache for a superblock
* @sb: superblock
@@ -883,9 +922,16 @@ void shrink_dcache_sb(struct super_block *sb)
spin_lock(&sb->s_dentry_lru_lock);
while (!list_empty(&sb->s_dentry_lru)) {
- list_splice_init(&sb->s_dentry_lru, &tmp);
+ /*
+ * account for removal here so we don't need to handle it later
+ * even though the dentry is no longer on the lru list.
+ */
spin_unlock(&sb->s_dentry_lru_lock);
- shrink_dentry_list(&tmp);
+ list_splice_init(&sb->s_dentry_lru, &tmp);
+ this_cpu_sub(nr_dentry_unused, sb->s_nr_dentry_unused);
+ sb->s_nr_dentry_unused = 0;
+
+ shrink_dcache_list(&tmp);
spin_lock(&sb->s_dentry_lru_lock);
}
spin_unlock(&sb->s_dentry_lru_lock);
--
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^ permalink raw reply related [flat|nested] 151+ messages in thread* Re: [PATCH v6 00/31] kmemcg shrinkers
2013-05-14 5:22 ` Dave Chinner
@ 2013-05-14 5:45 ` Dave Chinner
2013-05-14 7:38 ` Glauber Costa
1 sibling, 0 replies; 151+ messages in thread
From: Dave Chinner @ 2013-05-14 5:45 UTC (permalink / raw)
To: Glauber Costa
Cc: Glauber Costa, linux-mm, cgroups, Andrew Morton, Greg Thelen,
kamezawa.hiroyu, Michal Hocko, Johannes Weiner, linux-fsdevel
On Tue, May 14, 2013 at 03:22:44PM +1000, Dave Chinner wrote:
> On Tue, May 14, 2013 at 11:48:05AM +1000, Dave Chinner wrote:
...
> patch 4 needs some work:
>
> - fix the above leak shrink list leak
> - fix the scope of the sb locking inside shrink_dcache_sb()
> - remove the readditional of dentry_lru_prune().
>
> The reworked patch below does this.
And has a compile warning in it. And seeing as other patches need to
be rebased as a result of this change, I'll post the new patches as
responses to the patches that need to be modified....
Cheers,
Dave.
--
Dave Chinner
david@fromorbit.com
--
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^ permalink raw reply [flat|nested] 151+ messages in thread
* Re: [PATCH v6 00/31] kmemcg shrinkers
2013-05-14 5:22 ` Dave Chinner
@ 2013-05-14 7:38 ` Glauber Costa
2013-05-14 7:38 ` Glauber Costa
1 sibling, 0 replies; 151+ messages in thread
From: Glauber Costa @ 2013-05-14 7:38 UTC (permalink / raw)
To: Dave Chinner
Cc: Glauber Costa, linux-mm, cgroups, Andrew Morton, Greg Thelen,
kamezawa.hiroyu, Michal Hocko, Johannes Weiner, linux-fsdevel
On 05/14/2013 09:22 AM, Dave Chinner wrote:
> I've found the problem. dentry_kill() returns the current dentry if
> it cannot lock the dentry->d_inode or the dentry->d_parent, and when
> that happens try_prune_one_dentry() silently fails to prune the
> dentry. But, at this point, we've already removed the dentry from
> both the LRU and the shrink list, and so it gets dropped on the
> floor.
>
Great. I had already an idea that it had something to do with a dentry
being removed from the LRU and not being put back, but I was looking at
the wrong circumstance. oz, oz oi oi oi!
> patch 4 needs some work:
>
> - fix the above leak shrink list leak
> - fix the scope of the sb locking inside shrink_dcache_sb()
> - remove the readditional of dentry_lru_prune().
I readded this just because there are more work that needs to be done
upon prune that is always the same. This is specially true in later
patches, IIRC. I don't think dentry_lru_prune() has anything to do
directly with the problem we are seeing now, and this is just a question
of duplicated code vs not. But I am ultimately fine either way.
--
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^ permalink raw reply [flat|nested] 151+ messages in thread
* Re: [PATCH v6 00/31] kmemcg shrinkers
@ 2013-05-14 7:38 ` Glauber Costa
0 siblings, 0 replies; 151+ messages in thread
From: Glauber Costa @ 2013-05-14 7:38 UTC (permalink / raw)
To: Dave Chinner
Cc: Glauber Costa, linux-mm, cgroups, Andrew Morton, Greg Thelen,
kamezawa.hiroyu, Michal Hocko, Johannes Weiner, linux-fsdevel
On 05/14/2013 09:22 AM, Dave Chinner wrote:
> I've found the problem. dentry_kill() returns the current dentry if
> it cannot lock the dentry->d_inode or the dentry->d_parent, and when
> that happens try_prune_one_dentry() silently fails to prune the
> dentry. But, at this point, we've already removed the dentry from
> both the LRU and the shrink list, and so it gets dropped on the
> floor.
>
Great. I had already an idea that it had something to do with a dentry
being removed from the LRU and not being put back, but I was looking at
the wrong circumstance. oz, oz oi oi oi!
> patch 4 needs some work:
>
> - fix the above leak shrink list leak
> - fix the scope of the sb locking inside shrink_dcache_sb()
> - remove the readditional of dentry_lru_prune().
I readded this just because there are more work that needs to be done
upon prune that is always the same. This is specially true in later
patches, IIRC. I don't think dentry_lru_prune() has anything to do
directly with the problem we are seeing now, and this is just a question
of duplicated code vs not. But I am ultimately fine either way.
--
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the body to majordomo@kvack.org. For more info on Linux MM,
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^ permalink raw reply [flat|nested] 151+ messages in thread