* + mm-shrinkers-make-count-and-scan-in-shrinker-debugfs-lockless.patch added to mm-unstable branch
@ 2023-03-13 19:10 Andrew Morton
0 siblings, 0 replies; 2+ messages in thread
From: Andrew Morton @ 2023-03-13 19:10 UTC (permalink / raw)
To: mm-commits, vbabka, tkhai, sultan, shy828301, shakeelb,
roman.gushchin, penguin-kernel, paulmck, muchun.song, mhocko,
hannes, david, dave, christian.koenig, zhengqi.arch, akpm
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The patch titled
Subject: mm: shrinkers: make count and scan in shrinker debugfs lockless
has been added to the -mm mm-unstable branch. Its filename is
mm-shrinkers-make-count-and-scan-in-shrinker-debugfs-lockless.patch
This patch will shortly appear at
https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/mm-shrinkers-make-count-and-scan-in-shrinker-debugfs-lockless.patch
This patch will later appear in the mm-unstable branch at
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
Before you just go and hit "reply", please:
a) Consider who else should be cc'ed
b) Prefer to cc a suitable mailing list as well
c) Ideally: find the original patch on the mailing list and do a
reply-to-all to that, adding suitable additional cc's
*** Remember to use Documentation/process/submit-checklist.rst when testing your code ***
The -mm tree is included into linux-next via the mm-everything
branch at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
and is updated there every 2-3 working days
------------------------------------------------------
From: Qi Zheng <zhengqi.arch@bytedance.com>
Subject: mm: shrinkers: make count and scan in shrinker debugfs lockless
Date: Mon, 13 Mar 2023 19:28:16 +0800
Like global and memcg slab shrink, also use SRCU to make count and scan
operations in memory shrinker debugfs lockless.
Link: https://lkml.kernel.org/r/20230313112819.38938-6-zhengqi.arch@bytedance.com
Signed-off-by: Qi Zheng <zhengqi.arch@bytedance.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Acked-by: Kirill Tkhai <tkhai@ya.ru>
Cc: Christian König <christian.koenig@amd.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Davidlohr Bueso <dave@stgolabs.net>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Muchun Song <muchun.song@linux.dev>
Cc: Paul E. McKenney <paulmck@kernel.org>
Cc: Roman Gushchin <roman.gushchin@linux.dev>
Cc: Shakeel Butt <shakeelb@google.com>
Cc: Sultan Alsawaf <sultan@kerneltoast.com>
Cc: Tetsuo Handa <penguin-kernel@i-love.sakura.ne.jp>
Cc: Yang Shi <shy828301@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---
--- a/mm/shrinker_debug.c~mm-shrinkers-make-count-and-scan-in-shrinker-debugfs-lockless
+++ a/mm/shrinker_debug.c
@@ -5,10 +5,12 @@
#include <linux/seq_file.h>
#include <linux/shrinker.h>
#include <linux/memcontrol.h>
+#include <linux/srcu.h>
/* defined in vmscan.c */
extern struct rw_semaphore shrinker_rwsem;
extern struct list_head shrinker_list;
+extern struct srcu_struct shrinker_srcu;
static DEFINE_IDA(shrinker_debugfs_ida);
static struct dentry *shrinker_debugfs_root;
@@ -49,18 +51,13 @@ static int shrinker_debugfs_count_show(s
struct mem_cgroup *memcg;
unsigned long total;
bool memcg_aware;
- int ret, nid;
+ int ret = 0, nid, srcu_idx;
count_per_node = kcalloc(nr_node_ids, sizeof(unsigned long), GFP_KERNEL);
if (!count_per_node)
return -ENOMEM;
- ret = down_read_killable(&shrinker_rwsem);
- if (ret) {
- kfree(count_per_node);
- return ret;
- }
- rcu_read_lock();
+ srcu_idx = srcu_read_lock(&shrinker_srcu);
memcg_aware = shrinker->flags & SHRINKER_MEMCG_AWARE;
@@ -91,8 +88,7 @@ static int shrinker_debugfs_count_show(s
}
} while ((memcg = mem_cgroup_iter(NULL, memcg, NULL)) != NULL);
- rcu_read_unlock();
- up_read(&shrinker_rwsem);
+ srcu_read_unlock(&shrinker_srcu, srcu_idx);
kfree(count_per_node);
return ret;
@@ -115,9 +111,8 @@ static ssize_t shrinker_debugfs_scan_wri
.gfp_mask = GFP_KERNEL,
};
struct mem_cgroup *memcg = NULL;
- int nid;
+ int nid, srcu_idx;
char kbuf[72];
- ssize_t ret;
read_len = size < (sizeof(kbuf) - 1) ? size : (sizeof(kbuf) - 1);
if (copy_from_user(kbuf, buf, read_len))
@@ -146,11 +141,7 @@ static ssize_t shrinker_debugfs_scan_wri
return -EINVAL;
}
- ret = down_read_killable(&shrinker_rwsem);
- if (ret) {
- mem_cgroup_put(memcg);
- return ret;
- }
+ srcu_idx = srcu_read_lock(&shrinker_srcu);
sc.nid = nid;
sc.memcg = memcg;
@@ -159,7 +150,7 @@ static ssize_t shrinker_debugfs_scan_wri
shrinker->scan_objects(shrinker, &sc);
- up_read(&shrinker_rwsem);
+ srcu_read_unlock(&shrinker_srcu, srcu_idx);
mem_cgroup_put(memcg);
return size;
_
Patches currently in -mm which might be from zhengqi.arch@bytedance.com are
mm-vmscan-add-a-map_nr_max-field-to-shrinker_info.patch
mm-vmscan-make-global-slab-shrink-lockless.patch
mm-vmscan-make-memcg-slab-shrink-lockless.patch
mm-shrinkers-make-count-and-scan-in-shrinker-debugfs-lockless.patch
mm-vmscan-hold-write-lock-to-reparent-shrinker-nr_deferred.patch
mm-vmscan-remove-shrinker_rwsem-from-synchronize_shrinkers.patch
mm-shrinkers-convert-shrinker_rwsem-to-mutex.patch
^ permalink raw reply [flat|nested] 2+ messages in thread
* + mm-shrinkers-make-count-and-scan-in-shrinker-debugfs-lockless.patch added to mm-unstable branch
@ 2023-03-07 22:25 Andrew Morton
0 siblings, 0 replies; 2+ messages in thread
From: Andrew Morton @ 2023-03-07 22:25 UTC (permalink / raw)
To: mm-commits, tkhai, sultan, shy828301, shakeelb, rppt,
roman.gushchin, penguin-kernel, paulmck, muchun.song, mhocko,
hannes, david, dave, zhengqi.arch, akpm
The patch titled
Subject: mm: shrinkers: make count and scan in shrinker debugfs lockless
has been added to the -mm mm-unstable branch. Its filename is
mm-shrinkers-make-count-and-scan-in-shrinker-debugfs-lockless.patch
This patch will shortly appear at
https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/mm-shrinkers-make-count-and-scan-in-shrinker-debugfs-lockless.patch
This patch will later appear in the mm-unstable branch at
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
Before you just go and hit "reply", please:
a) Consider who else should be cc'ed
b) Prefer to cc a suitable mailing list as well
c) Ideally: find the original patch on the mailing list and do a
reply-to-all to that, adding suitable additional cc's
*** Remember to use Documentation/process/submit-checklist.rst when testing your code ***
The -mm tree is included into linux-next via the mm-everything
branch at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
and is updated there every 2-3 working days
------------------------------------------------------
From: Qi Zheng <zhengqi.arch@bytedance.com>
Subject: mm: shrinkers: make count and scan in shrinker debugfs lockless
Date: Tue, 7 Mar 2023 14:56:02 +0800
Like global and memcg slab shrink, also use SRCU to make count and scan
operations in memory shrinker debugfs lockless.
Link: https://lkml.kernel.org/r/20230307065605.58209-6-zhengqi.arch@bytedance.com
Signed-off-by: Qi Zheng <zhengqi.arch@bytedance.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Davidlohr Bueso <dave@stgolabs.net>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Kirill Tkhai <tkhai@ya.ru>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Muchun Song <muchun.song@linux.dev>
Cc: Paul E. McKenney <paulmck@kernel.org>
Cc: Roman Gushchin <roman.gushchin@linux.dev>
Cc: Shakeel Butt <shakeelb@google.com>
Cc: Sultan Alsawaf <sultan@kerneltoast.com>
Cc: Tetsuo Handa <penguin-kernel@i-love.sakura.ne.jp>
Cc: Yang Shi <shy828301@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---
mm/shrinker_debug.c | 24 +++++++-----------------
1 file changed, 7 insertions(+), 17 deletions(-)
--- a/mm/shrinker_debug.c~mm-shrinkers-make-count-and-scan-in-shrinker-debugfs-lockless
+++ a/mm/shrinker_debug.c
@@ -9,6 +9,7 @@
/* defined in vmscan.c */
extern struct rw_semaphore shrinker_rwsem;
extern struct list_head shrinker_list;
+extern struct srcu_struct shrinker_srcu;
static DEFINE_IDA(shrinker_debugfs_ida);
static struct dentry *shrinker_debugfs_root;
@@ -49,18 +50,13 @@ static int shrinker_debugfs_count_show(s
struct mem_cgroup *memcg;
unsigned long total;
bool memcg_aware;
- int ret, nid;
+ int ret = 0, nid, srcu_idx;
count_per_node = kcalloc(nr_node_ids, sizeof(unsigned long), GFP_KERNEL);
if (!count_per_node)
return -ENOMEM;
- ret = down_read_killable(&shrinker_rwsem);
- if (ret) {
- kfree(count_per_node);
- return ret;
- }
- rcu_read_lock();
+ srcu_idx = srcu_read_lock(&shrinker_srcu);
memcg_aware = shrinker->flags & SHRINKER_MEMCG_AWARE;
@@ -91,8 +87,7 @@ static int shrinker_debugfs_count_show(s
}
} while ((memcg = mem_cgroup_iter(NULL, memcg, NULL)) != NULL);
- rcu_read_unlock();
- up_read(&shrinker_rwsem);
+ srcu_read_unlock(&shrinker_srcu, srcu_idx);
kfree(count_per_node);
return ret;
@@ -115,9 +110,8 @@ static ssize_t shrinker_debugfs_scan_wri
.gfp_mask = GFP_KERNEL,
};
struct mem_cgroup *memcg = NULL;
- int nid;
+ int nid, srcu_idx;
char kbuf[72];
- ssize_t ret;
read_len = size < (sizeof(kbuf) - 1) ? size : (sizeof(kbuf) - 1);
if (copy_from_user(kbuf, buf, read_len))
@@ -146,11 +140,7 @@ static ssize_t shrinker_debugfs_scan_wri
return -EINVAL;
}
- ret = down_read_killable(&shrinker_rwsem);
- if (ret) {
- mem_cgroup_put(memcg);
- return ret;
- }
+ srcu_idx = srcu_read_lock(&shrinker_srcu);
sc.nid = nid;
sc.memcg = memcg;
@@ -159,7 +149,7 @@ static ssize_t shrinker_debugfs_scan_wri
shrinker->scan_objects(shrinker, &sc);
- up_read(&shrinker_rwsem);
+ srcu_read_unlock(&shrinker_srcu, srcu_idx);
mem_cgroup_put(memcg);
return size;
_
Patches currently in -mm which might be from zhengqi.arch@bytedance.com are
mm-vmscan-add-a-map_nr_max-field-to-shrinker_info.patch
mm-vmscan-make-global-slab-shrink-lockless.patch
mm-vmscan-make-memcg-slab-shrink-lockless.patch
mm-shrinkers-make-count-and-scan-in-shrinker-debugfs-lockless.patch
mm-vmscan-hold-write-lock-to-reparent-shrinker-nr_deferred.patch
mm-vmscan-remove-shrinker_rwsem-from-synchronize_shrinkers.patch
mm-shrinkers-convert-shrinker_rwsem-to-mutex.patch
^ permalink raw reply [flat|nested] 2+ messages in thread
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2023-03-13 19:10 + mm-shrinkers-make-count-and-scan-in-shrinker-debugfs-lockless.patch added to mm-unstable branch Andrew Morton
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2023-03-07 22:25 Andrew Morton
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