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* [PATCH 00/17] Optimize list lru memory consumption
@ 2021-05-11 10:46 Muchun Song
  2021-05-11 10:46 ` [PATCH 01/17] mm: list_lru: fix list_lru_count_one() return value Muchun Song
                   ` (16 more replies)
  0 siblings, 17 replies; 20+ messages in thread
From: Muchun Song @ 2021-05-11 10:46 UTC (permalink / raw)
  To: willy, akpm, hannes, mhocko, vdavydov.dev, shakeelb, guro,
	shy828301, alexs, richard.weiyang, david, trond.myklebust,
	anna.schumaker
  Cc: linux-fsdevel, linux-kernel, linux-mm, linux-nfs, zhengqi.arch,
	duanxiongchun, fam.zheng, Muchun Song

In our server, we found a suspected memory leak problem. The kmalloc-32
consumes more than 6GB of memory. Other kmem_caches consume less than 2GB
memory.

After our in-depth analysis, the memory consumption of kmalloc-32 slab
cache is the cause of list_lru_one allocation.

  crash> p memcg_nr_cache_ids
  memcg_nr_cache_ids = $2 = 24574

memcg_nr_cache_ids is very large and memory consumption of each list_lru
can be calculated with the following formula.

  num_numa_node * memcg_nr_cache_ids * 32 (kmalloc-32)

There are 4 numa nodes in our system, so each list_lru consumes ~3MB.

  crash> list super_blocks | wc -l
  952

Every mount will register 2 list lrus, one is for inode, another is for
dentry. There are 952 super_blocks. So the total memory is 952 * 2 * 3
MB (~5.6GB). But now the number of memory cgroups is less than 500. So I
guess more than 12286 memory cgroups have been created on this machine (I
do not know why there are so many cgroups, it may be a user's bug or
the user really want to do that). Because memcg_nr_cache_ids has not been
reduced to a suitable value. This can waste a lot of memory. If we want
to reduce memcg_nr_cache_ids, we have to reboot the server. This is not
what we want.

In order to reduce memcg_nr_cache_ids, I had posted a patchset [1] to do
this. But this did not fundamentally solve the problem.

We currently allocate scope for every memcg to be able to tracked on every
not on every superblock instantiated in the system, regardless of whether
that superblock is even accessible to that memcg.

These huge memcg counts come from container hosts where memcgs are confined
to just a small subset of the total number of superblocks that instantiated
at any given point in time.

For these systems with huge container counts, list_lru does not need the
capability of tracking every memcg on every superblock.

What it comes down to is that the list_lru is only needed for a given memcg
if that memcg is instatiating and freeing objects on a given list_lru.

As Dave said, "Which makes me think we should be moving more towards 'add the
memcg to the list_lru at the first insert' model rather than 'instantiate
all at memcg init time just in case'."

This patchset aims to optimize the list lru memory consumption from different
aspects.

Patch 1-6 are code simplification.
Patch 7 converts the array from per-memcg per-node to per-memcg
Patch 9-15 let list_lru allocation dynamically.
Patch 17 use xarray to optimize per memcg pointer array size.

I had done a easy test to show the optimization. I create 10k memory cgroups
and mount 10k filesystems in the systems. We use free command to show how many
memory does the systems comsumes after this operation.

        +------------------------------------------------+
        |      condition        |   memory consumption   |
        +-----------------------+------------------------+
        | without this patchset |        24464 MB        |
        +-----------------------+------------------------+
        |     after patch 7     |        21957 MB        | <--------+
        +-----------------------+------------------------+          |
        |     after patch 15    |         6895 MB        |          |
        +-----------------------+------------------------+          |
        |     after patch 17    |         4367 MB        |          |
        +-----------------------+------------------------+          |
                                                                    |
        The more the number of nodes, the more obvious the effect---+

BTW, there was a recent discussion [2] on the same issue.

[1] https://lore.kernel.org/linux-fsdevel/20210428094949.43579-1-songmuchun@bytedance.com/
[2] https://lore.kernel.org/linux-fsdevel/20210405054848.GA1077931@in.ibm.com/

Muchun Song (17):
  mm: list_lru: fix list_lru_count_one() return value
  mm: memcontrol: remove kmemcg_id reparenting
  mm: memcontrol: remove the kmem states
  mm: memcontrol: move memcg_online_kmem() to mem_cgroup_css_online()
  mm: list_lru: remove holding lru node lock
  mm: list_lru: only add the memcg aware lrus to the list
  mm: list_lru: optimize the array of per memcg lists
  mm: list_lru: remove memcg_aware from struct list_lru
  mm: introduce kmem_cache_alloc_lru
  fs: introduce alloc_inode_sb() to allocate filesystems specific inode
  mm: dcache: use kmem_cache_alloc_lru() to allocate dentry
  xarray: replace kmem_cache_alloc with kmem_cache_alloc_lru
  mm: workingset: allocate list_lru on xa_node allocation
  nfs42: use a specific kmem_cache to allocate nfs4_xattr_entry
  mm: list_lru: allocate list_lru_one only when needed
  mm: list_lru: rename memcg_drain_all_list_lrus to
    memcg_reparent_list_lrus
  mm: list_lru: replace linear array with xarray

 drivers/dax/super.c        |   2 +-
 fs/9p/vfs_inode.c          |   2 +-
 fs/adfs/super.c            |   2 +-
 fs/affs/super.c            |   2 +-
 fs/afs/super.c             |   2 +-
 fs/befs/linuxvfs.c         |   2 +-
 fs/bfs/inode.c             |   2 +-
 fs/block_dev.c             |   2 +-
 fs/btrfs/inode.c           |   2 +-
 fs/ceph/inode.c            |   2 +-
 fs/cifs/cifsfs.c           |   2 +-
 fs/coda/inode.c            |   2 +-
 fs/dcache.c                |   3 +-
 fs/ecryptfs/super.c        |   2 +-
 fs/efs/super.c             |   2 +-
 fs/erofs/super.c           |   2 +-
 fs/exfat/super.c           |   2 +-
 fs/ext2/super.c            |   2 +-
 fs/ext4/super.c            |   2 +-
 fs/f2fs/super.c            |   2 +-
 fs/fat/inode.c             |   2 +-
 fs/freevxfs/vxfs_super.c   |   2 +-
 fs/fuse/inode.c            |   2 +-
 fs/gfs2/super.c            |   2 +-
 fs/hfs/super.c             |   2 +-
 fs/hfsplus/super.c         |   2 +-
 fs/hostfs/hostfs_kern.c    |   2 +-
 fs/hpfs/super.c            |   2 +-
 fs/hugetlbfs/inode.c       |   2 +-
 fs/inode.c                 |   2 +-
 fs/isofs/inode.c           |   2 +-
 fs/jffs2/super.c           |   2 +-
 fs/jfs/super.c             |   2 +-
 fs/minix/inode.c           |   2 +-
 fs/nfs/inode.c             |   2 +-
 fs/nfs/nfs42xattr.c        |  95 +++++-----
 fs/nilfs2/super.c          |   2 +-
 fs/ntfs/inode.c            |   2 +-
 fs/ocfs2/dlmfs/dlmfs.c     |   2 +-
 fs/ocfs2/super.c           |   2 +-
 fs/openpromfs/inode.c      |   2 +-
 fs/orangefs/super.c        |   2 +-
 fs/overlayfs/super.c       |   2 +-
 fs/proc/inode.c            |   2 +-
 fs/qnx4/inode.c            |   2 +-
 fs/qnx6/inode.c            |   2 +-
 fs/reiserfs/super.c        |   2 +-
 fs/romfs/super.c           |   2 +-
 fs/squashfs/super.c        |   2 +-
 fs/sysv/inode.c            |   2 +-
 fs/ubifs/super.c           |   2 +-
 fs/udf/super.c             |   2 +-
 fs/ufs/super.c             |   2 +-
 fs/vboxsf/super.c          |   2 +-
 fs/xfs/xfs_icache.c        |   3 +-
 fs/zonefs/super.c          |   2 +-
 include/linux/fs.h         |   7 +
 include/linux/list_lru.h   |  24 +--
 include/linux/memcontrol.h |  31 ++--
 include/linux/slab.h       |   4 +
 include/linux/swap.h       |   5 +-
 include/linux/xarray.h     |   9 +-
 ipc/mqueue.c               |   2 +-
 lib/xarray.c               |  10 +-
 mm/list_lru.c              | 430 +++++++++++++++++++++------------------------
 mm/memcontrol.c            | 154 +++-------------
 mm/shmem.c                 |   2 +-
 mm/slab.c                  |  39 ++--
 mm/slab.h                  |  17 +-
 mm/slub.c                  |  42 +++--
 mm/workingset.c            |   2 +-
 net/socket.c               |   2 +-
 net/sunrpc/rpc_pipe.c      |   2 +-
 73 files changed, 460 insertions(+), 529 deletions(-)

-- 
2.11.0


^ permalink raw reply	[flat|nested] 20+ messages in thread

* [PATCH 01/17] mm: list_lru: fix list_lru_count_one() return value
  2021-05-11 10:46 [PATCH 00/17] Optimize list lru memory consumption Muchun Song
@ 2021-05-11 10:46 ` Muchun Song
  2021-05-11 10:46 ` [PATCH 02/17] mm: memcontrol: remove kmemcg_id reparenting Muchun Song
                   ` (15 subsequent siblings)
  16 siblings, 0 replies; 20+ messages in thread
From: Muchun Song @ 2021-05-11 10:46 UTC (permalink / raw)
  To: willy, akpm, hannes, mhocko, vdavydov.dev, shakeelb, guro,
	shy828301, alexs, richard.weiyang, david, trond.myklebust,
	anna.schumaker
  Cc: linux-fsdevel, linux-kernel, linux-mm, linux-nfs, zhengqi.arch,
	duanxiongchun, fam.zheng, Muchun Song

Since commit 2788cf0c401c ("memcg: reparent list_lrus and free kmemcg_id
on css offline"), the ->nr_items can be negative during memory cgroup
reparenting. In this case, list_lru_count_one() returns an unusual and
huge value. Ii can surprise users. So let it return zero when ->nr_items
is negative.

Signed-off-by: Muchun Song <songmuchun@bytedance.com>
---
 mm/list_lru.c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/mm/list_lru.c b/mm/list_lru.c
index cd58790d0fb3..4962d48d4410 100644
--- a/mm/list_lru.c
+++ b/mm/list_lru.c
@@ -176,13 +176,16 @@ unsigned long list_lru_count_one(struct list_lru *lru,
 {
 	struct list_lru_node *nlru = &lru->node[nid];
 	struct list_lru_one *l;
-	unsigned long count;
+	long count;
 
 	rcu_read_lock();
 	l = list_lru_from_memcg_idx(nlru, memcg_cache_id(memcg));
 	count = READ_ONCE(l->nr_items);
 	rcu_read_unlock();
 
+	if (unlikely(count < 0))
+		count = 0;
+
 	return count;
 }
 EXPORT_SYMBOL_GPL(list_lru_count_one);
-- 
2.11.0


^ permalink raw reply	[flat|nested] 20+ messages in thread

* [PATCH 02/17] mm: memcontrol: remove kmemcg_id reparenting
  2021-05-11 10:46 [PATCH 00/17] Optimize list lru memory consumption Muchun Song
  2021-05-11 10:46 ` [PATCH 01/17] mm: list_lru: fix list_lru_count_one() return value Muchun Song
@ 2021-05-11 10:46 ` Muchun Song
  2021-05-11 10:46 ` [PATCH 03/17] mm: memcontrol: remove the kmem states Muchun Song
                   ` (14 subsequent siblings)
  16 siblings, 0 replies; 20+ messages in thread
From: Muchun Song @ 2021-05-11 10:46 UTC (permalink / raw)
  To: willy, akpm, hannes, mhocko, vdavydov.dev, shakeelb, guro,
	shy828301, alexs, richard.weiyang, david, trond.myklebust,
	anna.schumaker
  Cc: linux-fsdevel, linux-kernel, linux-mm, linux-nfs, zhengqi.arch,
	duanxiongchun, fam.zheng, Muchun Song

Since slab objects and kmem pages are charged to object cgroup instead
of memory cgroup, memcg_reparent_objcgs() will reparent this cgroup and
all its descendants to the parent cgroup. This already makes further
list_lru_add()'s add elements to the parent's list. So we do not need
to change kmemcg_id of an offline cgroup to its parent's id. It is just
waste CPU cycles. Just remove those redundant code.

Signed-off-by: Muchun Song <songmuchun@bytedance.com>
---
 mm/memcontrol.c | 20 ++------------------
 1 file changed, 2 insertions(+), 18 deletions(-)

diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index 64ada9e650a5..21e12312509c 100644
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -3485,8 +3485,7 @@ static int memcg_online_kmem(struct mem_cgroup *memcg)
 
 static void memcg_offline_kmem(struct mem_cgroup *memcg)
 {
-	struct cgroup_subsys_state *css;
-	struct mem_cgroup *parent, *child;
+	struct mem_cgroup *parent;
 	int kmemcg_id;
 
 	if (memcg->kmem_state != KMEM_ONLINE)
@@ -3503,22 +3502,7 @@ static void memcg_offline_kmem(struct mem_cgroup *memcg)
 	kmemcg_id = memcg->kmemcg_id;
 	BUG_ON(kmemcg_id < 0);
 
-	/*
-	 * Change kmemcg_id of this cgroup and all its descendants to the
-	 * parent's id, and then move all entries from this cgroup's list_lrus
-	 * to ones of the parent. After we have finished, all list_lrus
-	 * corresponding to this cgroup are guaranteed to remain empty. The
-	 * ordering is imposed by list_lru_node->lock taken by
-	 * memcg_drain_all_list_lrus().
-	 */
-	rcu_read_lock(); /* can be called from css_free w/o cgroup_mutex */
-	css_for_each_descendant_pre(css, &memcg->css) {
-		child = mem_cgroup_from_css(css);
-		BUG_ON(child->kmemcg_id != kmemcg_id);
-		child->kmemcg_id = parent->kmemcg_id;
-	}
-	rcu_read_unlock();
-
+	/* memcg_reparent_objcgs() must be called before this. */
 	memcg_drain_all_list_lrus(kmemcg_id, parent);
 
 	memcg_free_cache_id(kmemcg_id);
-- 
2.11.0


^ permalink raw reply	[flat|nested] 20+ messages in thread

* [PATCH 03/17] mm: memcontrol: remove the kmem states
  2021-05-11 10:46 [PATCH 00/17] Optimize list lru memory consumption Muchun Song
  2021-05-11 10:46 ` [PATCH 01/17] mm: list_lru: fix list_lru_count_one() return value Muchun Song
  2021-05-11 10:46 ` [PATCH 02/17] mm: memcontrol: remove kmemcg_id reparenting Muchun Song
@ 2021-05-11 10:46 ` Muchun Song
  2021-05-11 10:46 ` [PATCH 04/17] mm: memcontrol: move memcg_online_kmem() to mem_cgroup_css_online() Muchun Song
                   ` (13 subsequent siblings)
  16 siblings, 0 replies; 20+ messages in thread
From: Muchun Song @ 2021-05-11 10:46 UTC (permalink / raw)
  To: willy, akpm, hannes, mhocko, vdavydov.dev, shakeelb, guro,
	shy828301, alexs, richard.weiyang, david, trond.myklebust,
	anna.schumaker
  Cc: linux-fsdevel, linux-kernel, linux-mm, linux-nfs, zhengqi.arch,
	duanxiongchun, fam.zheng, Muchun Song

Now the kmem states is only used to indicate whether the kmem is
offlined. But we can use ->kmemcg_id to do the same thing. So
remove the kmem states to simplify the code.

Signed-off-by: Muchun Song <songmuchun@bytedance.com>
---
 include/linux/memcontrol.h |  7 -------
 mm/memcontrol.c            | 10 ++--------
 2 files changed, 2 insertions(+), 15 deletions(-)

diff --git a/include/linux/memcontrol.h b/include/linux/memcontrol.h
index c193be760709..6350c563c7b8 100644
--- a/include/linux/memcontrol.h
+++ b/include/linux/memcontrol.h
@@ -182,12 +182,6 @@ struct mem_cgroup_thresholds {
 	struct mem_cgroup_threshold_ary *spare;
 };
 
-enum memcg_kmem_state {
-	KMEM_NONE,
-	KMEM_ALLOCATED,
-	KMEM_ONLINE,
-};
-
 #if defined(CONFIG_SMP)
 struct memcg_padding {
 	char x[0];
@@ -320,7 +314,6 @@ struct mem_cgroup {
 
 #ifdef CONFIG_MEMCG_KMEM
 	int kmemcg_id;
-	enum memcg_kmem_state kmem_state;
 	struct obj_cgroup __rcu *objcg;
 	struct list_head objcg_list; /* list of inherited objcgs */
 #endif
diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index 21e12312509c..e161a319982a 100644
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -3461,7 +3461,6 @@ static int memcg_online_kmem(struct mem_cgroup *memcg)
 		return 0;
 
 	BUG_ON(memcg->kmemcg_id >= 0);
-	BUG_ON(memcg->kmem_state);
 
 	memcg_id = memcg_alloc_cache_id();
 	if (memcg_id < 0)
@@ -3478,7 +3477,6 @@ static int memcg_online_kmem(struct mem_cgroup *memcg)
 	static_branch_enable(&memcg_kmem_enabled_key);
 
 	memcg->kmemcg_id = memcg_id;
-	memcg->kmem_state = KMEM_ONLINE;
 
 	return 0;
 }
@@ -3488,11 +3486,6 @@ static void memcg_offline_kmem(struct mem_cgroup *memcg)
 	struct mem_cgroup *parent;
 	int kmemcg_id;
 
-	if (memcg->kmem_state != KMEM_ONLINE)
-		return;
-
-	memcg->kmem_state = KMEM_ALLOCATED;
-
 	parent = parent_mem_cgroup(memcg);
 	if (!parent)
 		parent = root_mem_cgroup;
@@ -3506,12 +3499,13 @@ static void memcg_offline_kmem(struct mem_cgroup *memcg)
 	memcg_drain_all_list_lrus(kmemcg_id, parent);
 
 	memcg_free_cache_id(kmemcg_id);
+	memcg->kmemcg_id = -1;
 }
 
 static void memcg_free_kmem(struct mem_cgroup *memcg)
 {
 	/* css_alloc() failed, offlining didn't happen */
-	if (unlikely(memcg->kmem_state == KMEM_ONLINE))
+	if (unlikely(memcg->kmemcg_id != -1))
 		memcg_offline_kmem(memcg);
 }
 #else
-- 
2.11.0


^ permalink raw reply	[flat|nested] 20+ messages in thread

* [PATCH 04/17] mm: memcontrol: move memcg_online_kmem() to mem_cgroup_css_online()
  2021-05-11 10:46 [PATCH 00/17] Optimize list lru memory consumption Muchun Song
                   ` (2 preceding siblings ...)
  2021-05-11 10:46 ` [PATCH 03/17] mm: memcontrol: remove the kmem states Muchun Song
@ 2021-05-11 10:46 ` Muchun Song
  2021-05-11 10:46 ` [PATCH 05/17] mm: list_lru: remove holding lru node lock Muchun Song
                   ` (12 subsequent siblings)
  16 siblings, 0 replies; 20+ messages in thread
From: Muchun Song @ 2021-05-11 10:46 UTC (permalink / raw)
  To: willy, akpm, hannes, mhocko, vdavydov.dev, shakeelb, guro,
	shy828301, alexs, richard.weiyang, david, trond.myklebust,
	anna.schumaker
  Cc: linux-fsdevel, linux-kernel, linux-mm, linux-nfs, zhengqi.arch,
	duanxiongchun, fam.zheng, Muchun Song

Move memcg_online_kmem() to mem_cgroup_css_online() to simplify the
code. In this case, we can remove memcg_free_kmem().

Signed-off-by: Muchun Song <songmuchun@bytedance.com>
---
 mm/memcontrol.c | 41 ++++++++++++++++-------------------------
 1 file changed, 16 insertions(+), 25 deletions(-)

diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index e161a319982a..0d1c09873bad 100644
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -3460,6 +3460,9 @@ static int memcg_online_kmem(struct mem_cgroup *memcg)
 	if (cgroup_memory_nokmem)
 		return 0;
 
+	if (mem_cgroup_is_root(memcg))
+		return 0;
+
 	BUG_ON(memcg->kmemcg_id >= 0);
 
 	memcg_id = memcg_alloc_cache_id();
@@ -3486,6 +3489,9 @@ static void memcg_offline_kmem(struct mem_cgroup *memcg)
 	struct mem_cgroup *parent;
 	int kmemcg_id;
 
+	if (mem_cgroup_is_root(memcg))
+		return;
+
 	parent = parent_mem_cgroup(memcg);
 	if (!parent)
 		parent = root_mem_cgroup;
@@ -3499,14 +3505,6 @@ static void memcg_offline_kmem(struct mem_cgroup *memcg)
 	memcg_drain_all_list_lrus(kmemcg_id, parent);
 
 	memcg_free_cache_id(kmemcg_id);
-	memcg->kmemcg_id = -1;
-}
-
-static void memcg_free_kmem(struct mem_cgroup *memcg)
-{
-	/* css_alloc() failed, offlining didn't happen */
-	if (unlikely(memcg->kmemcg_id != -1))
-		memcg_offline_kmem(memcg);
 }
 #else
 static int memcg_online_kmem(struct mem_cgroup *memcg)
@@ -3516,9 +3514,6 @@ static int memcg_online_kmem(struct mem_cgroup *memcg)
 static void memcg_offline_kmem(struct mem_cgroup *memcg)
 {
 }
-static void memcg_free_kmem(struct mem_cgroup *memcg)
-{
-}
 #endif /* CONFIG_MEMCG_KMEM */
 
 static int memcg_update_kmem_max(struct mem_cgroup *memcg,
@@ -5047,7 +5042,6 @@ mem_cgroup_css_alloc(struct cgroup_subsys_state *parent_css)
 {
 	struct mem_cgroup *parent = mem_cgroup_from_css(parent_css);
 	struct mem_cgroup *memcg, *old_memcg;
-	long error = -ENOMEM;
 
 	old_memcg = set_active_memcg(parent);
 	memcg = mem_cgroup_alloc();
@@ -5077,38 +5071,36 @@ mem_cgroup_css_alloc(struct cgroup_subsys_state *parent_css)
 	}
 
 	/* The following stuff does not apply to the root */
-	error = memcg_online_kmem(memcg);
-	if (error)
-		goto fail;
-
 	if (cgroup_subsys_on_dfl(memory_cgrp_subsys) && !cgroup_memory_nosocket)
 		static_branch_inc(&memcg_sockets_enabled_key);
 
 	return &memcg->css;
-fail:
-	mem_cgroup_id_remove(memcg);
-	mem_cgroup_free(memcg);
-	return ERR_PTR(error);
 }
 
 static int mem_cgroup_css_online(struct cgroup_subsys_state *css)
 {
 	struct mem_cgroup *memcg = mem_cgroup_from_css(css);
 
+	if (memcg_online_kmem(memcg))
+		goto remove_id;
+
 	/*
 	 * A memcg must be visible for expand_shrinker_info()
 	 * by the time the maps are allocated. So, we allocate maps
 	 * here, when for_each_mem_cgroup() can't skip it.
 	 */
-	if (alloc_shrinker_info(memcg)) {
-		mem_cgroup_id_remove(memcg);
-		return -ENOMEM;
-	}
+	if (alloc_shrinker_info(memcg))
+		goto offline_kmem;
 
 	/* Online state pins memcg ID, memcg ID pins CSS */
 	refcount_set(&memcg->id.ref, 1);
 	css_get(css);
 	return 0;
+offline_kmem:
+	memcg_offline_kmem(memcg);
+remove_id:
+	mem_cgroup_id_remove(memcg);
+	return -ENOMEM;
 }
 
 static void mem_cgroup_css_offline(struct cgroup_subsys_state *css)
@@ -5166,7 +5158,6 @@ static void mem_cgroup_css_free(struct cgroup_subsys_state *css)
 	cancel_work_sync(&memcg->high_work);
 	mem_cgroup_remove_from_trees(memcg);
 	free_shrinker_info(memcg);
-	memcg_free_kmem(memcg);
 	mem_cgroup_free(memcg);
 }
 
-- 
2.11.0


^ permalink raw reply	[flat|nested] 20+ messages in thread

* [PATCH 05/17] mm: list_lru: remove holding lru node lock
  2021-05-11 10:46 [PATCH 00/17] Optimize list lru memory consumption Muchun Song
                   ` (3 preceding siblings ...)
  2021-05-11 10:46 ` [PATCH 04/17] mm: memcontrol: move memcg_online_kmem() to mem_cgroup_css_online() Muchun Song
@ 2021-05-11 10:46 ` Muchun Song
  2021-05-11 10:46 ` [PATCH 06/17] mm: list_lru: only add the memcg aware lrus to the list Muchun Song
                   ` (11 subsequent siblings)
  16 siblings, 0 replies; 20+ messages in thread
From: Muchun Song @ 2021-05-11 10:46 UTC (permalink / raw)
  To: willy, akpm, hannes, mhocko, vdavydov.dev, shakeelb, guro,
	shy828301, alexs, richard.weiyang, david, trond.myklebust,
	anna.schumaker
  Cc: linux-fsdevel, linux-kernel, linux-mm, linux-nfs, zhengqi.arch,
	duanxiongchun, fam.zheng, Muchun Song

Since commit e5bc3af7734f ("rcu: Consolidate PREEMPT and !PREEMPT
synchronize_rcu()"), the critical section of spinlock can serve
as RCU read-side critical section. So we can remove redundant
locking from memcg_update_list_lru_node().

Signed-off-by: Muchun Song <songmuchun@bytedance.com>
---
 mm/list_lru.c | 11 +----------
 1 file changed, 1 insertion(+), 10 deletions(-)

diff --git a/mm/list_lru.c b/mm/list_lru.c
index 4962d48d4410..e86d4d055d3c 100644
--- a/mm/list_lru.c
+++ b/mm/list_lru.c
@@ -403,18 +403,9 @@ static int memcg_update_list_lru_node(struct list_lru_node *nlru,
 
 	memcpy(&new->lru, &old->lru, old_size * sizeof(void *));
 
-	/*
-	 * The locking below allows readers that hold nlru->lock avoid taking
-	 * rcu_read_lock (see list_lru_from_memcg_idx).
-	 *
-	 * Since list_lru_{add,del} may be called under an IRQ-safe lock,
-	 * we have to use IRQ-safe primitives here to avoid deadlock.
-	 */
-	spin_lock_irq(&nlru->lock);
 	rcu_assign_pointer(nlru->memcg_lrus, new);
-	spin_unlock_irq(&nlru->lock);
-
 	kvfree_rcu(old, rcu);
+
 	return 0;
 }
 
-- 
2.11.0


^ permalink raw reply	[flat|nested] 20+ messages in thread

* [PATCH 06/17] mm: list_lru: only add the memcg aware lrus to the list
  2021-05-11 10:46 [PATCH 00/17] Optimize list lru memory consumption Muchun Song
                   ` (4 preceding siblings ...)
  2021-05-11 10:46 ` [PATCH 05/17] mm: list_lru: remove holding lru node lock Muchun Song
@ 2021-05-11 10:46 ` Muchun Song
  2021-05-11 10:46 ` [PATCH 07/17] mm: list_lru: optimize the array of per memcg lists Muchun Song
                   ` (10 subsequent siblings)
  16 siblings, 0 replies; 20+ messages in thread
From: Muchun Song @ 2021-05-11 10:46 UTC (permalink / raw)
  To: willy, akpm, hannes, mhocko, vdavydov.dev, shakeelb, guro,
	shy828301, alexs, richard.weiyang, david, trond.myklebust,
	anna.schumaker
  Cc: linux-fsdevel, linux-kernel, linux-mm, linux-nfs, zhengqi.arch,
	duanxiongchun, fam.zheng, Muchun Song

We need to traverse every lru in the list_lrus in some routines, but skip
the non memcg aware lru. Actually, we can only add the memcg aware lrus to
the list. This can be efficient.

Signed-off-by: Muchun Song <songmuchun@bytedance.com>
---
 mm/list_lru.c | 25 +++++++++++--------------
 1 file changed, 11 insertions(+), 14 deletions(-)

diff --git a/mm/list_lru.c b/mm/list_lru.c
index e86d4d055d3c..bed699edabe5 100644
--- a/mm/list_lru.c
+++ b/mm/list_lru.c
@@ -18,8 +18,16 @@
 static LIST_HEAD(list_lrus);
 static DEFINE_MUTEX(list_lrus_mutex);
 
+static inline bool list_lru_memcg_aware(struct list_lru *lru)
+{
+	return lru->memcg_aware;
+}
+
 static void list_lru_register(struct list_lru *lru)
 {
+	if (!list_lru_memcg_aware(lru))
+		return;
+
 	mutex_lock(&list_lrus_mutex);
 	list_add(&lru->list, &list_lrus);
 	mutex_unlock(&list_lrus_mutex);
@@ -27,6 +35,9 @@ static void list_lru_register(struct list_lru *lru)
 
 static void list_lru_unregister(struct list_lru *lru)
 {
+	if (!list_lru_memcg_aware(lru))
+		return;
+
 	mutex_lock(&list_lrus_mutex);
 	list_del(&lru->list);
 	mutex_unlock(&list_lrus_mutex);
@@ -37,11 +48,6 @@ static int lru_shrinker_id(struct list_lru *lru)
 	return lru->shrinker_id;
 }
 
-static inline bool list_lru_memcg_aware(struct list_lru *lru)
-{
-	return lru->memcg_aware;
-}
-
 static inline struct list_lru_one *
 list_lru_from_memcg_idx(struct list_lru_node *nlru, int idx)
 {
@@ -460,9 +466,6 @@ static int memcg_update_list_lru(struct list_lru *lru,
 {
 	int i;
 
-	if (!list_lru_memcg_aware(lru))
-		return 0;
-
 	for_each_node(i) {
 		if (memcg_update_list_lru_node(&lru->node[i],
 					       old_size, new_size))
@@ -485,9 +488,6 @@ static void memcg_cancel_update_list_lru(struct list_lru *lru,
 {
 	int i;
 
-	if (!list_lru_memcg_aware(lru))
-		return;
-
 	for_each_node(i)
 		memcg_cancel_update_list_lru_node(&lru->node[i],
 						  old_size, new_size);
@@ -546,9 +546,6 @@ static void memcg_drain_list_lru(struct list_lru *lru,
 {
 	int i;
 
-	if (!list_lru_memcg_aware(lru))
-		return;
-
 	for_each_node(i)
 		memcg_drain_list_lru_node(lru, i, src_idx, dst_memcg);
 }
-- 
2.11.0


^ permalink raw reply	[flat|nested] 20+ messages in thread

* [PATCH 07/17] mm: list_lru: optimize the array of per memcg lists
  2021-05-11 10:46 [PATCH 00/17] Optimize list lru memory consumption Muchun Song
                   ` (5 preceding siblings ...)
  2021-05-11 10:46 ` [PATCH 06/17] mm: list_lru: only add the memcg aware lrus to the list Muchun Song
@ 2021-05-11 10:46 ` Muchun Song
  2021-05-11 10:46 ` [PATCH 08/17] mm: list_lru: remove memcg_aware from struct list_lru Muchun Song
                   ` (9 subsequent siblings)
  16 siblings, 0 replies; 20+ messages in thread
From: Muchun Song @ 2021-05-11 10:46 UTC (permalink / raw)
  To: willy, akpm, hannes, mhocko, vdavydov.dev, shakeelb, guro,
	shy828301, alexs, richard.weiyang, david, trond.myklebust,
	anna.schumaker
  Cc: linux-fsdevel, linux-kernel, linux-mm, linux-nfs, zhengqi.arch,
	duanxiongchun, fam.zheng, Muchun Song

The list_lru use an array to store the list_lru_one pointers, which is
per memcg per node. What if we run 10k+ containers in the system? The
size of the arrays for every list lru can be 10k * number_of_node *
sizeof(void *). We can convert the array to per memcg instead of per
memcg per node. It can help us save memory especially when there are
many nodes in the system. And also simplify the code.

Signed-off-by: Muchun Song <songmuchun@bytedance.com>
---
 include/linux/list_lru.h |  17 +++--
 mm/list_lru.c            | 192 +++++++++++++++++------------------------------
 2 files changed, 80 insertions(+), 129 deletions(-)

diff --git a/include/linux/list_lru.h b/include/linux/list_lru.h
index 9dcaa3e582c9..228bef9fdd0b 100644
--- a/include/linux/list_lru.h
+++ b/include/linux/list_lru.h
@@ -31,10 +31,15 @@ struct list_lru_one {
 	long			nr_items;
 };
 
+struct list_lru_per_memcg {
+	/* array of per cgroup per node lists, indexed by node id */
+	struct list_lru_one	nodes[0];
+};
+
 struct list_lru_memcg {
-	struct rcu_head		rcu;
+	struct rcu_head			rcu;
 	/* array of per cgroup lists, indexed by memcg_cache_id */
-	struct list_lru_one	*lru[];
+	struct list_lru_per_memcg	*lrus[0];
 };
 
 struct list_lru_node {
@@ -42,11 +47,7 @@ struct list_lru_node {
 	spinlock_t		lock;
 	/* global list, used for the root cgroup in cgroup aware lrus */
 	struct list_lru_one	lru;
-#ifdef CONFIG_MEMCG_KMEM
-	/* for cgroup aware lrus points to per cgroup lists, otherwise NULL */
-	struct list_lru_memcg	__rcu *memcg_lrus;
-#endif
-	long nr_items;
+	long			nr_items;
 } ____cacheline_aligned_in_smp;
 
 struct list_lru {
@@ -55,6 +56,8 @@ struct list_lru {
 	struct list_head	list;
 	int			shrinker_id;
 	bool			memcg_aware;
+	/* for cgroup aware lrus points to per cgroup lists, otherwise NULL */
+	struct list_lru_memcg	__rcu *memcg_lrus;
 #endif
 };
 
diff --git a/mm/list_lru.c b/mm/list_lru.c
index bed699edabe5..57c55916cc1c 100644
--- a/mm/list_lru.c
+++ b/mm/list_lru.c
@@ -49,35 +49,38 @@ static int lru_shrinker_id(struct list_lru *lru)
 }
 
 static inline struct list_lru_one *
-list_lru_from_memcg_idx(struct list_lru_node *nlru, int idx)
+list_lru_from_memcg_idx(struct list_lru *lru, int nid, int idx)
 {
 	struct list_lru_memcg *memcg_lrus;
+	struct list_lru_node *nlru = &lru->node[nid];
+
 	/*
 	 * Either lock or RCU protects the array of per cgroup lists
-	 * from relocation (see memcg_update_list_lru_node).
+	 * from relocation (see memcg_update_list_lru).
 	 */
-	memcg_lrus = rcu_dereference_check(nlru->memcg_lrus,
+	memcg_lrus = rcu_dereference_check(lru->memcg_lrus,
 					   lockdep_is_held(&nlru->lock));
 	if (memcg_lrus && idx >= 0)
-		return memcg_lrus->lru[idx];
+		return &memcg_lrus->lrus[idx]->nodes[nid];
 	return &nlru->lru;
 }
 
 static inline struct list_lru_one *
-list_lru_from_kmem(struct list_lru_node *nlru, void *ptr,
+list_lru_from_kmem(struct list_lru *lru, int nid, void *ptr,
 		   struct mem_cgroup **memcg_ptr)
 {
+	struct list_lru_node *nlru = &lru->node[nid];
 	struct list_lru_one *l = &nlru->lru;
 	struct mem_cgroup *memcg = NULL;
 
-	if (!nlru->memcg_lrus)
+	if (!lru->memcg_lrus)
 		goto out;
 
 	memcg = mem_cgroup_from_obj(ptr);
 	if (!memcg)
 		goto out;
 
-	l = list_lru_from_memcg_idx(nlru, memcg_cache_id(memcg));
+	l = list_lru_from_memcg_idx(lru, nid, memcg_cache_id(memcg));
 out:
 	if (memcg_ptr)
 		*memcg_ptr = memcg;
@@ -103,18 +106,18 @@ static inline bool list_lru_memcg_aware(struct list_lru *lru)
 }
 
 static inline struct list_lru_one *
-list_lru_from_memcg_idx(struct list_lru_node *nlru, int idx)
+list_lru_from_memcg_idx(struct list_lru *lru, int nid, int idx)
 {
-	return &nlru->lru;
+	return &lru->node[nid].lru;
 }
 
 static inline struct list_lru_one *
-list_lru_from_kmem(struct list_lru_node *nlru, void *ptr,
+list_lru_from_kmem(struct list_lru *lru, int nid, void *ptr,
 		   struct mem_cgroup **memcg_ptr)
 {
 	if (memcg_ptr)
 		*memcg_ptr = NULL;
-	return &nlru->lru;
+	return &lru->node[nid].lru;
 }
 #endif /* CONFIG_MEMCG_KMEM */
 
@@ -127,7 +130,7 @@ bool list_lru_add(struct list_lru *lru, struct list_head *item)
 
 	spin_lock(&nlru->lock);
 	if (list_empty(item)) {
-		l = list_lru_from_kmem(nlru, item, &memcg);
+		l = list_lru_from_kmem(lru, nid, item, &memcg);
 		list_add_tail(item, &l->list);
 		/* Set shrinker bit if the first element was added */
 		if (!l->nr_items++)
@@ -150,7 +153,7 @@ bool list_lru_del(struct list_lru *lru, struct list_head *item)
 
 	spin_lock(&nlru->lock);
 	if (!list_empty(item)) {
-		l = list_lru_from_kmem(nlru, item, NULL);
+		l = list_lru_from_kmem(lru, nid, item, NULL);
 		list_del_init(item);
 		l->nr_items--;
 		nlru->nr_items--;
@@ -180,12 +183,11 @@ EXPORT_SYMBOL_GPL(list_lru_isolate_move);
 unsigned long list_lru_count_one(struct list_lru *lru,
 				 int nid, struct mem_cgroup *memcg)
 {
-	struct list_lru_node *nlru = &lru->node[nid];
 	struct list_lru_one *l;
 	long count;
 
 	rcu_read_lock();
-	l = list_lru_from_memcg_idx(nlru, memcg_cache_id(memcg));
+	l = list_lru_from_memcg_idx(lru, nid, memcg_cache_id(memcg));
 	count = READ_ONCE(l->nr_items);
 	rcu_read_unlock();
 
@@ -206,16 +208,16 @@ unsigned long list_lru_count_node(struct list_lru *lru, int nid)
 EXPORT_SYMBOL_GPL(list_lru_count_node);
 
 static unsigned long
-__list_lru_walk_one(struct list_lru_node *nlru, int memcg_idx,
+__list_lru_walk_one(struct list_lru *lru, int nid, int memcg_idx,
 		    list_lru_walk_cb isolate, void *cb_arg,
 		    unsigned long *nr_to_walk)
 {
-
+	struct list_lru_node *nlru = &lru->node[nid];
 	struct list_lru_one *l;
 	struct list_head *item, *n;
 	unsigned long isolated = 0;
 
-	l = list_lru_from_memcg_idx(nlru, memcg_idx);
+	l = list_lru_from_memcg_idx(lru, nid, memcg_idx);
 restart:
 	list_for_each_safe(item, n, &l->list) {
 		enum lru_status ret;
@@ -272,8 +274,8 @@ list_lru_walk_one(struct list_lru *lru, int nid, struct mem_cgroup *memcg,
 	unsigned long ret;
 
 	spin_lock(&nlru->lock);
-	ret = __list_lru_walk_one(nlru, memcg_cache_id(memcg), isolate, cb_arg,
-				  nr_to_walk);
+	ret = __list_lru_walk_one(lru, nid, memcg_cache_id(memcg), isolate,
+				  cb_arg, nr_to_walk);
 	spin_unlock(&nlru->lock);
 	return ret;
 }
@@ -288,8 +290,8 @@ list_lru_walk_one_irq(struct list_lru *lru, int nid, struct mem_cgroup *memcg,
 	unsigned long ret;
 
 	spin_lock_irq(&nlru->lock);
-	ret = __list_lru_walk_one(nlru, memcg_cache_id(memcg), isolate, cb_arg,
-				  nr_to_walk);
+	ret = __list_lru_walk_one(lru, nid, memcg_cache_id(memcg), isolate,
+				  cb_arg, nr_to_walk);
 	spin_unlock_irq(&nlru->lock);
 	return ret;
 }
@@ -308,7 +310,7 @@ unsigned long list_lru_walk_node(struct list_lru *lru, int nid,
 			struct list_lru_node *nlru = &lru->node[nid];
 
 			spin_lock(&nlru->lock);
-			isolated += __list_lru_walk_one(nlru, memcg_idx,
+			isolated += __list_lru_walk_one(lru, nid, memcg_idx,
 							isolate, cb_arg,
 							nr_to_walk);
 			spin_unlock(&nlru->lock);
@@ -328,169 +330,115 @@ static void init_one_lru(struct list_lru_one *l)
 }
 
 #ifdef CONFIG_MEMCG_KMEM
-static void __memcg_destroy_list_lru_node(struct list_lru_memcg *memcg_lrus,
-					  int begin, int end)
+static void memcg_destroy_list_lru_range(struct list_lru_memcg *memcg_lrus,
+					 int begin, int end)
 {
 	int i;
 
 	for (i = begin; i < end; i++)
-		kfree(memcg_lrus->lru[i]);
+		kfree(memcg_lrus->lrus[i]);
 }
 
-static int __memcg_init_list_lru_node(struct list_lru_memcg *memcg_lrus,
-				      int begin, int end)
+static int memcg_init_list_lru_range(struct list_lru_memcg *memcg_lrus,
+				     int begin, int end)
 {
 	int i;
 
 	for (i = begin; i < end; i++) {
-		struct list_lru_one *l;
+		int nid;
+		struct list_lru_per_memcg *lru;
 
-		l = kmalloc(sizeof(struct list_lru_one), GFP_KERNEL);
-		if (!l)
+		lru = kmalloc(sizeof(*lru) + nr_node_ids * sizeof(lru->nodes[0]),
+			      GFP_KERNEL);
+		if (!lru)
 			goto fail;
 
-		init_one_lru(l);
-		memcg_lrus->lru[i] = l;
+		for_each_node(nid)
+			init_one_lru(&lru->nodes[nid]);
+		memcg_lrus->lrus[i] = lru;
 	}
 	return 0;
 fail:
-	__memcg_destroy_list_lru_node(memcg_lrus, begin, i);
+	memcg_destroy_list_lru_range(memcg_lrus, begin, i);
 	return -ENOMEM;
 }
 
-static int memcg_init_list_lru_node(struct list_lru_node *nlru)
+static int memcg_init_list_lru(struct list_lru *lru, bool memcg_aware)
 {
 	struct list_lru_memcg *memcg_lrus;
 	int size = memcg_nr_cache_ids;
 
+	lru->memcg_aware = memcg_aware;
+	if (!memcg_aware)
+		return 0;
+
 	memcg_lrus = kvmalloc(sizeof(*memcg_lrus) +
-			      size * sizeof(void *), GFP_KERNEL);
+			      size * sizeof(memcg_lrus->lrus[0]), GFP_KERNEL);
 	if (!memcg_lrus)
 		return -ENOMEM;
 
-	if (__memcg_init_list_lru_node(memcg_lrus, 0, size)) {
+	if (memcg_init_list_lru_range(memcg_lrus, 0, size)) {
 		kvfree(memcg_lrus);
 		return -ENOMEM;
 	}
-	RCU_INIT_POINTER(nlru->memcg_lrus, memcg_lrus);
+	RCU_INIT_POINTER(lru->memcg_lrus, memcg_lrus);
 
 	return 0;
 }
 
-static void memcg_destroy_list_lru_node(struct list_lru_node *nlru)
+static void memcg_destroy_list_lru(struct list_lru *lru)
 {
 	struct list_lru_memcg *memcg_lrus;
+
+	if (!list_lru_memcg_aware(lru))
+		return;
+
 	/*
 	 * This is called when shrinker has already been unregistered,
 	 * and nobody can use it. So, there is no need to use kvfree_rcu().
 	 */
-	memcg_lrus = rcu_dereference_protected(nlru->memcg_lrus, true);
-	__memcg_destroy_list_lru_node(memcg_lrus, 0, memcg_nr_cache_ids);
+	memcg_lrus = rcu_dereference_protected(lru->memcg_lrus, true);
+	memcg_destroy_list_lru_range(memcg_lrus, 0, memcg_nr_cache_ids);
 	kvfree(memcg_lrus);
 }
 
-static int memcg_update_list_lru_node(struct list_lru_node *nlru,
-				      int old_size, int new_size)
+static int memcg_update_list_lru(struct list_lru *lru, int old_size, int new_size)
 {
 	struct list_lru_memcg *old, *new;
 
 	BUG_ON(old_size > new_size);
 
-	old = rcu_dereference_protected(nlru->memcg_lrus,
+	old = rcu_dereference_protected(lru->memcg_lrus,
 					lockdep_is_held(&list_lrus_mutex));
-	new = kvmalloc(sizeof(*new) + new_size * sizeof(void *), GFP_KERNEL);
+	new = kvmalloc(sizeof(*new) + new_size * sizeof(new->lrus[0]), GFP_KERNEL);
 	if (!new)
 		return -ENOMEM;
 
-	if (__memcg_init_list_lru_node(new, old_size, new_size)) {
+	if (memcg_init_list_lru_range(new, old_size, new_size)) {
 		kvfree(new);
 		return -ENOMEM;
 	}
 
-	memcpy(&new->lru, &old->lru, old_size * sizeof(void *));
+	memcpy(&new->lrus, &old->lrus, old_size * sizeof(new->lrus[0]));
 
-	rcu_assign_pointer(nlru->memcg_lrus, new);
+	rcu_assign_pointer(lru->memcg_lrus, new);
 	kvfree_rcu(old, rcu);
 
 	return 0;
 }
 
-static void memcg_cancel_update_list_lru_node(struct list_lru_node *nlru,
-					      int old_size, int new_size)
-{
-	struct list_lru_memcg *memcg_lrus;
-
-	memcg_lrus = rcu_dereference_protected(nlru->memcg_lrus,
-					       lockdep_is_held(&list_lrus_mutex));
-	/* do not bother shrinking the array back to the old size, because we
-	 * cannot handle allocation failures here */
-	__memcg_destroy_list_lru_node(memcg_lrus, old_size, new_size);
-}
-
-static int memcg_init_list_lru(struct list_lru *lru, bool memcg_aware)
-{
-	int i;
-
-	lru->memcg_aware = memcg_aware;
-
-	if (!memcg_aware)
-		return 0;
-
-	for_each_node(i) {
-		if (memcg_init_list_lru_node(&lru->node[i]))
-			goto fail;
-	}
-	return 0;
-fail:
-	for (i = i - 1; i >= 0; i--) {
-		if (!lru->node[i].memcg_lrus)
-			continue;
-		memcg_destroy_list_lru_node(&lru->node[i]);
-	}
-	return -ENOMEM;
-}
-
-static void memcg_destroy_list_lru(struct list_lru *lru)
-{
-	int i;
-
-	if (!list_lru_memcg_aware(lru))
-		return;
-
-	for_each_node(i)
-		memcg_destroy_list_lru_node(&lru->node[i]);
-}
-
-static int memcg_update_list_lru(struct list_lru *lru,
-				 int old_size, int new_size)
-{
-	int i;
-
-	for_each_node(i) {
-		if (memcg_update_list_lru_node(&lru->node[i],
-					       old_size, new_size))
-			goto fail;
-	}
-	return 0;
-fail:
-	for (i = i - 1; i >= 0; i--) {
-		if (!lru->node[i].memcg_lrus)
-			continue;
-
-		memcg_cancel_update_list_lru_node(&lru->node[i],
-						  old_size, new_size);
-	}
-	return -ENOMEM;
-}
-
 static void memcg_cancel_update_list_lru(struct list_lru *lru,
 					 int old_size, int new_size)
 {
-	int i;
+	struct list_lru_memcg *memcg_lrus;
 
-	for_each_node(i)
-		memcg_cancel_update_list_lru_node(&lru->node[i],
-						  old_size, new_size);
+	memcg_lrus = rcu_dereference_protected(lru->memcg_lrus,
+					       lockdep_is_held(&list_lrus_mutex));
+	/*
+	 * Do not bother shrinking the array back to the old size, because we
+	 * cannot handle allocation failures here.
+	 */
+	memcg_destroy_list_lru_range(memcg_lrus, old_size, new_size);
 }
 
 int memcg_update_all_list_lrus(int new_size)
@@ -527,8 +475,8 @@ static void memcg_drain_list_lru_node(struct list_lru *lru, int nid,
 	 */
 	spin_lock_irq(&nlru->lock);
 
-	src = list_lru_from_memcg_idx(nlru, src_idx);
-	dst = list_lru_from_memcg_idx(nlru, dst_idx);
+	src = list_lru_from_memcg_idx(lru, nid, src_idx);
+	dst = list_lru_from_memcg_idx(lru, nid, dst_idx);
 
 	list_splice_init(&src->list, &dst->list);
 
-- 
2.11.0


^ permalink raw reply	[flat|nested] 20+ messages in thread

* [PATCH 08/17] mm: list_lru: remove memcg_aware from struct list_lru
  2021-05-11 10:46 [PATCH 00/17] Optimize list lru memory consumption Muchun Song
                   ` (6 preceding siblings ...)
  2021-05-11 10:46 ` [PATCH 07/17] mm: list_lru: optimize the array of per memcg lists Muchun Song
@ 2021-05-11 10:46 ` Muchun Song
  2021-05-11 10:46 ` [PATCH 09/17] mm: introduce kmem_cache_alloc_lru Muchun Song
                   ` (8 subsequent siblings)
  16 siblings, 0 replies; 20+ messages in thread
From: Muchun Song @ 2021-05-11 10:46 UTC (permalink / raw)
  To: willy, akpm, hannes, mhocko, vdavydov.dev, shakeelb, guro,
	shy828301, alexs, richard.weiyang, david, trond.myklebust,
	anna.schumaker
  Cc: linux-fsdevel, linux-kernel, linux-mm, linux-nfs, zhengqi.arch,
	duanxiongchun, fam.zheng, Muchun Song

We can use ->memcg_lrus to indicate if the lru is memcg aware. So
->memcg_aware is redundant and remove it.

Signed-off-by: Muchun Song <songmuchun@bytedance.com>
---
 include/linux/list_lru.h | 1 -
 mm/list_lru.c            | 9 +++++----
 2 files changed, 5 insertions(+), 5 deletions(-)

diff --git a/include/linux/list_lru.h b/include/linux/list_lru.h
index 228bef9fdd0b..00a13ad6128a 100644
--- a/include/linux/list_lru.h
+++ b/include/linux/list_lru.h
@@ -55,7 +55,6 @@ struct list_lru {
 #ifdef CONFIG_MEMCG_KMEM
 	struct list_head	list;
 	int			shrinker_id;
-	bool			memcg_aware;
 	/* for cgroup aware lrus points to per cgroup lists, otherwise NULL */
 	struct list_lru_memcg	__rcu *memcg_lrus;
 #endif
diff --git a/mm/list_lru.c b/mm/list_lru.c
index 57c55916cc1c..cf17ff5a5940 100644
--- a/mm/list_lru.c
+++ b/mm/list_lru.c
@@ -20,7 +20,7 @@ static DEFINE_MUTEX(list_lrus_mutex);
 
 static inline bool list_lru_memcg_aware(struct list_lru *lru)
 {
-	return lru->memcg_aware;
+	return !!lru->memcg_lrus;
 }
 
 static void list_lru_register(struct list_lru *lru)
@@ -73,7 +73,7 @@ list_lru_from_kmem(struct list_lru *lru, int nid, void *ptr,
 	struct list_lru_one *l = &nlru->lru;
 	struct mem_cgroup *memcg = NULL;
 
-	if (!lru->memcg_lrus)
+	if (!list_lru_memcg_aware(lru))
 		goto out;
 
 	memcg = mem_cgroup_from_obj(ptr);
@@ -368,9 +368,10 @@ static int memcg_init_list_lru(struct list_lru *lru, bool memcg_aware)
 	struct list_lru_memcg *memcg_lrus;
 	int size = memcg_nr_cache_ids;
 
-	lru->memcg_aware = memcg_aware;
-	if (!memcg_aware)
+	if (!memcg_aware) {
+		lru->memcg_lrus = NULL;
 		return 0;
+	}
 
 	memcg_lrus = kvmalloc(sizeof(*memcg_lrus) +
 			      size * sizeof(memcg_lrus->lrus[0]), GFP_KERNEL);
-- 
2.11.0


^ permalink raw reply	[flat|nested] 20+ messages in thread

* [PATCH 09/17] mm: introduce kmem_cache_alloc_lru
  2021-05-11 10:46 [PATCH 00/17] Optimize list lru memory consumption Muchun Song
                   ` (7 preceding siblings ...)
  2021-05-11 10:46 ` [PATCH 08/17] mm: list_lru: remove memcg_aware from struct list_lru Muchun Song
@ 2021-05-11 10:46 ` Muchun Song
  2021-05-11 10:46 ` [PATCH 10/17] fs: introduce alloc_inode_sb() to allocate filesystems specific inode Muchun Song
                   ` (7 subsequent siblings)
  16 siblings, 0 replies; 20+ messages in thread
From: Muchun Song @ 2021-05-11 10:46 UTC (permalink / raw)
  To: willy, akpm, hannes, mhocko, vdavydov.dev, shakeelb, guro,
	shy828301, alexs, richard.weiyang, david, trond.myklebust,
	anna.schumaker
  Cc: linux-fsdevel, linux-kernel, linux-mm, linux-nfs, zhengqi.arch,
	duanxiongchun, fam.zheng, Muchun Song

We currently allocate scope for every memcg to be able to tracked on
every not on every superblock instantiated in the system, regardless
of whether that superblock is even accessible to that memcg.

These huge memcg counts come from container hosts where memcgs are
confined to just a small subset of the total number of superblocks
that instantiated at any given point in time.

For these systems with huge container counts, list_lru does not need
the capability of tracking every memcg on every superblock. What it
comes down to is that adding the memcg to the list_lru at the first
insert. So introduce kmem_cache_alloc_lru to allocate objects and its
list_lru. In the later patch, we will convert all inode and dentry
allocation from kmem_cache_alloc to kmem_cache_alloc_lru.

Signed-off-by: Muchun Song <songmuchun@bytedance.com>
---
 include/linux/list_lru.h   |   3 ++
 include/linux/memcontrol.h |  14 ++++++
 include/linux/slab.h       |   4 ++
 mm/list_lru.c              | 116 ++++++++++++++++++++++++++++++++++++++++-----
 mm/memcontrol.c            |  14 ------
 mm/slab.c                  |  39 ++++++++++-----
 mm/slab.h                  |  17 ++++++-
 mm/slub.c                  |  42 ++++++++++------
 8 files changed, 197 insertions(+), 52 deletions(-)

diff --git a/include/linux/list_lru.h b/include/linux/list_lru.h
index 00a13ad6128a..2b2fdb4de96a 100644
--- a/include/linux/list_lru.h
+++ b/include/linux/list_lru.h
@@ -55,11 +55,14 @@ struct list_lru {
 #ifdef CONFIG_MEMCG_KMEM
 	struct list_head	list;
 	int			shrinker_id;
+	/* protects ->memcg_lrus->lrus[i] */
+	spinlock_t		lock;
 	/* for cgroup aware lrus points to per cgroup lists, otherwise NULL */
 	struct list_lru_memcg	__rcu *memcg_lrus;
 #endif
 };
 
+int list_lru_memcg_alloc(struct list_lru *lru, struct mem_cgroup *memcg, gfp_t gfp);
 void list_lru_destroy(struct list_lru *lru);
 int __list_lru_init(struct list_lru *lru, bool memcg_aware,
 		    struct lock_class_key *key, struct shrinker *shrinker);
diff --git a/include/linux/memcontrol.h b/include/linux/memcontrol.h
index 6350c563c7b8..96a85cff248a 100644
--- a/include/linux/memcontrol.h
+++ b/include/linux/memcontrol.h
@@ -517,6 +517,20 @@ static inline struct mem_cgroup *page_memcg_check(struct page *page)
 	return (struct mem_cgroup *)(memcg_data & ~MEMCG_DATA_FLAGS_MASK);
 }
 
+static inline struct mem_cgroup *get_mem_cgroup_from_objcg(struct obj_cgroup *objcg)
+{
+	struct mem_cgroup *memcg;
+
+	rcu_read_lock();
+retry:
+	memcg = obj_cgroup_memcg(objcg);
+	if (unlikely(!css_tryget(&memcg->css)))
+		goto retry;
+	rcu_read_unlock();
+
+	return memcg;
+}
+
 #ifdef CONFIG_MEMCG_KMEM
 /*
  * PageMemcgKmem - check if the page has MemcgKmem flag set
diff --git a/include/linux/slab.h b/include/linux/slab.h
index 2e09a0ac5d60..88aac607e968 100644
--- a/include/linux/slab.h
+++ b/include/linux/slab.h
@@ -392,8 +392,12 @@ static __always_inline unsigned int kmalloc_index(size_t size)
 }
 #endif /* !CONFIG_SLOB */
 
+struct list_lru;
+
 void *__kmalloc(size_t size, gfp_t flags) __assume_kmalloc_alignment __malloc;
 void *kmem_cache_alloc(struct kmem_cache *, gfp_t flags) __assume_slab_alignment __malloc;
+void *kmem_cache_alloc_lru(struct kmem_cache *s, struct list_lru *lru,
+			   gfp_t gfpflags) __assume_slab_alignment __malloc;
 void kmem_cache_free(struct kmem_cache *, void *);
 
 /*
diff --git a/mm/list_lru.c b/mm/list_lru.c
index cf17ff5a5940..182cb2a2e64f 100644
--- a/mm/list_lru.c
+++ b/mm/list_lru.c
@@ -339,23 +339,30 @@ static void memcg_destroy_list_lru_range(struct list_lru_memcg *memcg_lrus,
 		kfree(memcg_lrus->lrus[i]);
 }
 
+static struct list_lru_per_memcg *list_lru_per_memcg_alloc(gfp_t gfp)
+{
+	int nid;
+	struct list_lru_per_memcg *lru;
+
+	lru = kmalloc(sizeof(*lru) + nr_node_ids * sizeof(lru->nodes[0]), gfp);
+	if (!lru)
+		return NULL;
+
+	for_each_node(nid)
+		init_one_lru(&lru->nodes[nid]);
+
+	return lru;
+}
+
 static int memcg_init_list_lru_range(struct list_lru_memcg *memcg_lrus,
 				     int begin, int end)
 {
 	int i;
 
 	for (i = begin; i < end; i++) {
-		int nid;
-		struct list_lru_per_memcg *lru;
-
-		lru = kmalloc(sizeof(*lru) + nr_node_ids * sizeof(lru->nodes[0]),
-			      GFP_KERNEL);
-		if (!lru)
+		memcg_lrus->lrus[i] = list_lru_per_memcg_alloc(GFP_KERNEL);
+		if (!memcg_lrus->lrus[i])
 			goto fail;
-
-		for_each_node(nid)
-			init_one_lru(&lru->nodes[nid]);
-		memcg_lrus->lrus[i] = lru;
 	}
 	return 0;
 fail:
@@ -373,6 +380,8 @@ static int memcg_init_list_lru(struct list_lru *lru, bool memcg_aware)
 		return 0;
 	}
 
+	spin_lock_init(&lru->lock);
+
 	memcg_lrus = kvmalloc(sizeof(*memcg_lrus) +
 			      size * sizeof(memcg_lrus->lrus[0]), GFP_KERNEL);
 	if (!memcg_lrus)
@@ -420,9 +429,11 @@ static int memcg_update_list_lru(struct list_lru *lru, int old_size, int new_siz
 		return -ENOMEM;
 	}
 
+	spin_lock_irq(&lru->lock);
 	memcpy(&new->lrus, &old->lrus, old_size * sizeof(new->lrus[0]));
-
 	rcu_assign_pointer(lru->memcg_lrus, new);
+	spin_unlock_irq(&lru->lock);
+
 	kvfree_rcu(old, rcu);
 
 	return 0;
@@ -508,6 +519,89 @@ void memcg_drain_all_list_lrus(int src_idx, struct mem_cgroup *dst_memcg)
 		memcg_drain_list_lru(lru, src_idx, dst_memcg);
 	mutex_unlock(&list_lrus_mutex);
 }
+
+static bool list_lru_per_memcg_allocated(struct list_lru *lru,
+					 struct mem_cgroup *memcg)
+{
+	struct list_lru_memcg *memcg_lrus;
+	int idx = memcg_cache_id(memcg);
+
+	if (unlikely(idx < 0))
+		return true;
+
+	rcu_read_lock();
+	memcg_lrus = rcu_dereference(lru->memcg_lrus);
+	if (memcg_lrus->lrus[idx]) {
+		rcu_read_unlock();
+		return true;
+	}
+	rcu_read_unlock();
+
+	return false;
+}
+
+int list_lru_memcg_alloc(struct list_lru *lru, struct mem_cgroup *memcg, gfp_t gfp)
+{
+	unsigned long flags;
+	struct list_lru_memcg *memcg_lrus;
+	int i;
+
+	struct list_lru_memcg {
+		struct list_lru_per_memcg *mlru;
+		struct mem_cgroup *memcg;
+	} *table;
+
+	if (!list_lru_memcg_aware(lru))
+		return 0;
+
+	if (list_lru_per_memcg_allocated(lru, memcg))
+		return 0;
+
+	/*
+	 * The allocated list_lru_per_memcg array is not accounted directly.
+	 * Moreover, it should not come from DMA buffer and is not readily
+	 * reclaimable. So those GFP bits should be masked off.
+	 */
+	gfp &= ~(__GFP_DMA | __GFP_RECLAIMABLE | __GFP_ACCOUNT | __GFP_ZERO);
+	table = kmalloc_array(memcg->css.cgroup->level, sizeof(*table), gfp);
+	if (!table)
+		return -ENOMEM;
+
+	/*
+	 * Because the list_lru can be reparented to the parent cgroup's
+	 * list_lru, we should make sure that this cgroup and all its
+	 * ancestors have allocated list_lru_per_memcg.
+	 */
+	for (i = 0; memcg; memcg = parent_mem_cgroup(memcg), i++) {
+		if (list_lru_per_memcg_allocated(lru, memcg))
+			break;
+
+		table[i].memcg = memcg;
+		table[i].mlru = list_lru_per_memcg_alloc(gfp);
+		if (!table[i].mlru) {
+			while (i--)
+				kfree(table[i].mlru);
+			kfree(table);
+			return -ENOMEM;
+		}
+	}
+
+	spin_lock_irqsave(&lru->lock, flags);
+	memcg_lrus = rcu_dereference_protected(lru->memcg_lrus, true);
+	while (i--) {
+		int idx = memcg_cache_id(table[i].memcg);
+
+		if (memcg_lrus->lrus[idx])
+			kfree(table[i].mlru);
+		else
+			memcg_lrus->lrus[idx] = table[i].mlru;
+	}
+	spin_unlock_irqrestore(&lru->lock, flags);
+
+	kfree(table);
+
+	return 0;
+}
 #else
 static int memcg_init_list_lru(struct list_lru *lru, bool memcg_aware)
 {
diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index 0d1c09873bad..6aace39fd1a4 100644
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -2724,20 +2724,6 @@ static void commit_charge(struct page *page, struct mem_cgroup *memcg)
 	page->memcg_data = (unsigned long)memcg;
 }
 
-static struct mem_cgroup *get_mem_cgroup_from_objcg(struct obj_cgroup *objcg)
-{
-	struct mem_cgroup *memcg;
-
-	rcu_read_lock();
-retry:
-	memcg = obj_cgroup_memcg(objcg);
-	if (unlikely(!css_tryget(&memcg->css)))
-		goto retry;
-	rcu_read_unlock();
-
-	return memcg;
-}
-
 #ifdef CONFIG_MEMCG_KMEM
 int memcg_alloc_page_obj_cgroups(struct page *page, struct kmem_cache *s,
 				 gfp_t gfp, bool new_page)
diff --git a/mm/slab.c b/mm/slab.c
index d0f725637663..9a001aabc77b 100644
--- a/mm/slab.c
+++ b/mm/slab.c
@@ -3219,7 +3219,7 @@ slab_alloc_node(struct kmem_cache *cachep, gfp_t flags, int nodeid, size_t orig_
 	bool init = false;
 
 	flags &= gfp_allowed_mask;
-	cachep = slab_pre_alloc_hook(cachep, &objcg, 1, flags);
+	cachep = slab_pre_alloc_hook(cachep, NULL, &objcg, 1, flags);
 	if (unlikely(!cachep))
 		return NULL;
 
@@ -3295,7 +3295,8 @@ __do_cache_alloc(struct kmem_cache *cachep, gfp_t flags)
 #endif /* CONFIG_NUMA */
 
 static __always_inline void *
-slab_alloc(struct kmem_cache *cachep, gfp_t flags, size_t orig_size, unsigned long caller)
+slab_alloc(struct kmem_cache *cachep, struct list_lru *lru, gfp_t flags,
+	   size_t orig_size, unsigned long caller)
 {
 	unsigned long save_flags;
 	void *objp;
@@ -3303,7 +3304,7 @@ slab_alloc(struct kmem_cache *cachep, gfp_t flags, size_t orig_size, unsigned lo
 	bool init = false;
 
 	flags &= gfp_allowed_mask;
-	cachep = slab_pre_alloc_hook(cachep, &objcg, 1, flags);
+	cachep = slab_pre_alloc_hook(cachep, lru, &objcg, 1, flags);
 	if (unlikely(!cachep))
 		return NULL;
 
@@ -3492,6 +3493,18 @@ void ___cache_free(struct kmem_cache *cachep, void *objp,
 	__free_one(ac, objp);
 }
 
+static __always_inline
+void *__kmem_cache_alloc_lru(struct kmem_cache *cachep, struct list_lru *lru,
+			     gfp_t flags)
+{
+	void *ret = slab_alloc(cachep, lru, flags, cachep->object_size, _RET_IP_);
+
+	trace_kmem_cache_alloc(_RET_IP_, ret,
+			       cachep->object_size, cachep->size, flags);
+
+	return ret;
+}
+
 /**
  * kmem_cache_alloc - Allocate an object
  * @cachep: The cache to allocate from.
@@ -3504,15 +3517,17 @@ void ___cache_free(struct kmem_cache *cachep, void *objp,
  */
 void *kmem_cache_alloc(struct kmem_cache *cachep, gfp_t flags)
 {
-	void *ret = slab_alloc(cachep, flags, cachep->object_size, _RET_IP_);
-
-	trace_kmem_cache_alloc(_RET_IP_, ret,
-			       cachep->object_size, cachep->size, flags);
-
-	return ret;
+	return __kmem_cache_alloc_lru(cachep, NULL, flags);
 }
 EXPORT_SYMBOL(kmem_cache_alloc);
 
+void *kmem_cache_alloc_lru(struct kmem_cache *cachep, struct list_lru *lru,
+			   gfp_t flags)
+{
+	return __kmem_cache_alloc_lru(cachep, lru, flags);
+}
+EXPORT_SYMBOL(kmem_cache_alloc_lru);
+
 static __always_inline void
 cache_alloc_debugcheck_after_bulk(struct kmem_cache *s, gfp_t flags,
 				  size_t size, void **p, unsigned long caller)
@@ -3529,7 +3544,7 @@ int kmem_cache_alloc_bulk(struct kmem_cache *s, gfp_t flags, size_t size,
 	size_t i;
 	struct obj_cgroup *objcg = NULL;
 
-	s = slab_pre_alloc_hook(s, &objcg, size, flags);
+	s = slab_pre_alloc_hook(s, NULL, &objcg, size, flags);
 	if (!s)
 		return 0;
 
@@ -3570,7 +3585,7 @@ kmem_cache_alloc_trace(struct kmem_cache *cachep, gfp_t flags, size_t size)
 {
 	void *ret;
 
-	ret = slab_alloc(cachep, flags, size, _RET_IP_);
+	ret = slab_alloc(cachep, NULL, flags, size, _RET_IP_);
 
 	ret = kasan_kmalloc(cachep, ret, size, flags);
 	trace_kmalloc(_RET_IP_, ret,
@@ -3697,7 +3712,7 @@ static __always_inline void *__do_kmalloc(size_t size, gfp_t flags,
 	cachep = kmalloc_slab(size, flags);
 	if (unlikely(ZERO_OR_NULL_PTR(cachep)))
 		return cachep;
-	ret = slab_alloc(cachep, flags, size, caller);
+	ret = slab_alloc(cachep, NULL, flags, size, caller);
 
 	ret = kasan_kmalloc(cachep, ret, size, flags);
 	trace_kmalloc(caller, ret,
diff --git a/mm/slab.h b/mm/slab.h
index a7268072f017..55e4dea357c3 100644
--- a/mm/slab.h
+++ b/mm/slab.h
@@ -46,6 +46,7 @@ struct kmem_cache {
 #include <linux/kmemleak.h>
 #include <linux/random.h>
 #include <linux/sched/mm.h>
+#include <linux/list_lru.h>
 
 /*
  * State of the slab allocator.
@@ -262,6 +263,7 @@ static inline size_t obj_full_size(struct kmem_cache *s)
  * Returns false if the allocation should fail.
  */
 static inline bool memcg_slab_pre_alloc_hook(struct kmem_cache *s,
+					     struct list_lru *lru,
 					     struct obj_cgroup **objcgp,
 					     size_t objects, gfp_t flags)
 {
@@ -277,6 +279,17 @@ static inline bool memcg_slab_pre_alloc_hook(struct kmem_cache *s,
 	if (!objcg)
 		return true;
 
+	if (lru) {
+		struct mem_cgroup *memcg = get_mem_cgroup_from_objcg(objcg);
+
+		if (list_lru_memcg_alloc(lru, memcg, flags)) {
+			css_put(&memcg->css);
+			obj_cgroup_put(objcg);
+			return false;
+		}
+		css_put(&memcg->css);
+	}
+
 	if (obj_cgroup_charge(objcg, flags, objects * obj_full_size(s))) {
 		obj_cgroup_put(objcg);
 		return false;
@@ -394,6 +407,7 @@ static inline void memcg_free_page_obj_cgroups(struct page *page)
 }
 
 static inline bool memcg_slab_pre_alloc_hook(struct kmem_cache *s,
+					     struct list_lru *lru,
 					     struct obj_cgroup **objcgp,
 					     size_t objects, gfp_t flags)
 {
@@ -492,6 +506,7 @@ static inline size_t slab_ksize(const struct kmem_cache *s)
 }
 
 static inline struct kmem_cache *slab_pre_alloc_hook(struct kmem_cache *s,
+						     struct list_lru *lru,
 						     struct obj_cgroup **objcgp,
 						     size_t size, gfp_t flags)
 {
@@ -502,7 +517,7 @@ static inline struct kmem_cache *slab_pre_alloc_hook(struct kmem_cache *s,
 	if (should_failslab(s, flags))
 		return NULL;
 
-	if (!memcg_slab_pre_alloc_hook(s, objcgp, size, flags))
+	if (!memcg_slab_pre_alloc_hook(s, lru, objcgp, size, flags))
 		return NULL;
 
 	return s;
diff --git a/mm/slub.c b/mm/slub.c
index cb62496d7122..6566b0b2b062 100644
--- a/mm/slub.c
+++ b/mm/slub.c
@@ -2832,7 +2832,7 @@ static __always_inline void maybe_wipe_obj_freeptr(struct kmem_cache *s,
  *
  * Otherwise we can simply pick the next object from the lockless free list.
  */
-static __always_inline void *slab_alloc_node(struct kmem_cache *s,
+static __always_inline void *slab_alloc_node(struct kmem_cache *s, struct list_lru *lru,
 		gfp_t gfpflags, int node, unsigned long addr, size_t orig_size)
 {
 	void *object;
@@ -2842,7 +2842,7 @@ static __always_inline void *slab_alloc_node(struct kmem_cache *s,
 	struct obj_cgroup *objcg = NULL;
 	bool init = false;
 
-	s = slab_pre_alloc_hook(s, &objcg, 1, gfpflags);
+	s = slab_pre_alloc_hook(s, lru, &objcg, 1, gfpflags);
 	if (!s)
 		return NULL;
 
@@ -2926,27 +2926,41 @@ static __always_inline void *slab_alloc_node(struct kmem_cache *s,
 	return object;
 }
 
-static __always_inline void *slab_alloc(struct kmem_cache *s,
+static __always_inline void *slab_alloc(struct kmem_cache *s, struct list_lru *lru,
 		gfp_t gfpflags, unsigned long addr, size_t orig_size)
 {
-	return slab_alloc_node(s, gfpflags, NUMA_NO_NODE, addr, orig_size);
+	return slab_alloc_node(s, lru, gfpflags, NUMA_NO_NODE, addr, orig_size);
 }
 
-void *kmem_cache_alloc(struct kmem_cache *s, gfp_t gfpflags)
+static __always_inline
+void *__kmem_cache_alloc_lru(struct kmem_cache *s, struct list_lru *lru,
+			     gfp_t gfpflags)
 {
-	void *ret = slab_alloc(s, gfpflags, _RET_IP_, s->object_size);
+	void *ret = slab_alloc(s, lru, gfpflags, _RET_IP_, s->object_size);
 
 	trace_kmem_cache_alloc(_RET_IP_, ret, s->object_size,
 				s->size, gfpflags);
 
 	return ret;
 }
+
+void *kmem_cache_alloc(struct kmem_cache *s, gfp_t gfpflags)
+{
+	return __kmem_cache_alloc_lru(s, NULL, gfpflags);
+}
 EXPORT_SYMBOL(kmem_cache_alloc);
 
+void *kmem_cache_alloc_lru(struct kmem_cache *s, struct list_lru *lru,
+			   gfp_t gfpflags)
+{
+	return __kmem_cache_alloc_lru(s, lru, gfpflags);
+}
+EXPORT_SYMBOL(kmem_cache_alloc_lru);
+
 #ifdef CONFIG_TRACING
 void *kmem_cache_alloc_trace(struct kmem_cache *s, gfp_t gfpflags, size_t size)
 {
-	void *ret = slab_alloc(s, gfpflags, _RET_IP_, size);
+	void *ret = slab_alloc(s, NULL, gfpflags, _RET_IP_, size);
 	trace_kmalloc(_RET_IP_, ret, size, s->size, gfpflags);
 	ret = kasan_kmalloc(s, ret, size, gfpflags);
 	return ret;
@@ -2957,7 +2971,7 @@ EXPORT_SYMBOL(kmem_cache_alloc_trace);
 #ifdef CONFIG_NUMA
 void *kmem_cache_alloc_node(struct kmem_cache *s, gfp_t gfpflags, int node)
 {
-	void *ret = slab_alloc_node(s, gfpflags, node, _RET_IP_, s->object_size);
+	void *ret = slab_alloc_node(s, NULL, gfpflags, node, _RET_IP_, s->object_size);
 
 	trace_kmem_cache_alloc_node(_RET_IP_, ret,
 				    s->object_size, s->size, gfpflags, node);
@@ -2971,7 +2985,7 @@ void *kmem_cache_alloc_node_trace(struct kmem_cache *s,
 				    gfp_t gfpflags,
 				    int node, size_t size)
 {
-	void *ret = slab_alloc_node(s, gfpflags, node, _RET_IP_, size);
+	void *ret = slab_alloc_node(s, NULL, gfpflags, node, _RET_IP_, size);
 
 	trace_kmalloc_node(_RET_IP_, ret,
 			   size, s->size, gfpflags, node);
@@ -3322,7 +3336,7 @@ int kmem_cache_alloc_bulk(struct kmem_cache *s, gfp_t flags, size_t size,
 	struct obj_cgroup *objcg = NULL;
 
 	/* memcg and kmem_cache debug support */
-	s = slab_pre_alloc_hook(s, &objcg, size, flags);
+	s = slab_pre_alloc_hook(s, NULL, &objcg, size, flags);
 	if (unlikely(!s))
 		return false;
 	/*
@@ -4071,7 +4085,7 @@ void *__kmalloc(size_t size, gfp_t flags)
 	if (unlikely(ZERO_OR_NULL_PTR(s)))
 		return s;
 
-	ret = slab_alloc(s, flags, _RET_IP_, size);
+	ret = slab_alloc(s, NULL, flags, _RET_IP_, size);
 
 	trace_kmalloc(_RET_IP_, ret, size, s->size, flags);
 
@@ -4119,7 +4133,7 @@ void *__kmalloc_node(size_t size, gfp_t flags, int node)
 	if (unlikely(ZERO_OR_NULL_PTR(s)))
 		return s;
 
-	ret = slab_alloc_node(s, flags, node, _RET_IP_, size);
+	ret = slab_alloc_node(s, NULL, flags, node, _RET_IP_, size);
 
 	trace_kmalloc_node(_RET_IP_, ret, size, s->size, flags, node);
 
@@ -4581,7 +4595,7 @@ void *__kmalloc_track_caller(size_t size, gfp_t gfpflags, unsigned long caller)
 	if (unlikely(ZERO_OR_NULL_PTR(s)))
 		return s;
 
-	ret = slab_alloc(s, gfpflags, caller, size);
+	ret = slab_alloc(s, NULL, gfpflags, caller, size);
 
 	/* Honor the call site pointer we received. */
 	trace_kmalloc(caller, ret, size, s->size, gfpflags);
@@ -4612,7 +4626,7 @@ void *__kmalloc_node_track_caller(size_t size, gfp_t gfpflags,
 	if (unlikely(ZERO_OR_NULL_PTR(s)))
 		return s;
 
-	ret = slab_alloc_node(s, gfpflags, node, caller, size);
+	ret = slab_alloc_node(s, NULL, gfpflags, node, caller, size);
 
 	/* Honor the call site pointer we received. */
 	trace_kmalloc_node(caller, ret, size, s->size, gfpflags, node);
-- 
2.11.0


^ permalink raw reply	[flat|nested] 20+ messages in thread

* [PATCH 10/17] fs: introduce alloc_inode_sb() to allocate filesystems specific inode
  2021-05-11 10:46 [PATCH 00/17] Optimize list lru memory consumption Muchun Song
                   ` (8 preceding siblings ...)
  2021-05-11 10:46 ` [PATCH 09/17] mm: introduce kmem_cache_alloc_lru Muchun Song
@ 2021-05-11 10:46 ` Muchun Song
  2021-05-11 23:40   ` Dave Chinner
  2021-05-11 10:46 ` [PATCH 11/17] mm: dcache: use kmem_cache_alloc_lru() to allocate dentry Muchun Song
                   ` (6 subsequent siblings)
  16 siblings, 1 reply; 20+ messages in thread
From: Muchun Song @ 2021-05-11 10:46 UTC (permalink / raw)
  To: willy, akpm, hannes, mhocko, vdavydov.dev, shakeelb, guro,
	shy828301, alexs, richard.weiyang, david, trond.myklebust,
	anna.schumaker
  Cc: linux-fsdevel, linux-kernel, linux-mm, linux-nfs, zhengqi.arch,
	duanxiongchun, fam.zheng, Muchun Song

The allocated inode cache will be added into its memcg lru list later,
but we do not allocate list_lru in the later patch. So the caller should
call kmem_cache_alloc_lru() to allocate inode and related list_lru.
Introduce alloc_inode_sb() to do that and convert all inodes allocation
to it.

Signed-off-by: Muchun Song <songmuchun@bytedance.com>
---
 drivers/dax/super.c      | 2 +-
 fs/9p/vfs_inode.c        | 2 +-
 fs/adfs/super.c          | 2 +-
 fs/affs/super.c          | 2 +-
 fs/afs/super.c           | 2 +-
 fs/befs/linuxvfs.c       | 2 +-
 fs/bfs/inode.c           | 2 +-
 fs/block_dev.c           | 2 +-
 fs/btrfs/inode.c         | 2 +-
 fs/ceph/inode.c          | 2 +-
 fs/cifs/cifsfs.c         | 2 +-
 fs/coda/inode.c          | 2 +-
 fs/ecryptfs/super.c      | 2 +-
 fs/efs/super.c           | 2 +-
 fs/erofs/super.c         | 2 +-
 fs/exfat/super.c         | 2 +-
 fs/ext2/super.c          | 2 +-
 fs/ext4/super.c          | 2 +-
 fs/f2fs/super.c          | 2 +-
 fs/fat/inode.c           | 2 +-
 fs/freevxfs/vxfs_super.c | 2 +-
 fs/fuse/inode.c          | 2 +-
 fs/gfs2/super.c          | 2 +-
 fs/hfs/super.c           | 2 +-
 fs/hfsplus/super.c       | 2 +-
 fs/hostfs/hostfs_kern.c  | 2 +-
 fs/hpfs/super.c          | 2 +-
 fs/hugetlbfs/inode.c     | 2 +-
 fs/inode.c               | 2 +-
 fs/isofs/inode.c         | 2 +-
 fs/jffs2/super.c         | 2 +-
 fs/jfs/super.c           | 2 +-
 fs/minix/inode.c         | 2 +-
 fs/nfs/inode.c           | 2 +-
 fs/nilfs2/super.c        | 2 +-
 fs/ntfs/inode.c          | 2 +-
 fs/ocfs2/dlmfs/dlmfs.c   | 2 +-
 fs/ocfs2/super.c         | 2 +-
 fs/openpromfs/inode.c    | 2 +-
 fs/orangefs/super.c      | 2 +-
 fs/overlayfs/super.c     | 2 +-
 fs/proc/inode.c          | 2 +-
 fs/qnx4/inode.c          | 2 +-
 fs/qnx6/inode.c          | 2 +-
 fs/reiserfs/super.c      | 2 +-
 fs/romfs/super.c         | 2 +-
 fs/squashfs/super.c      | 2 +-
 fs/sysv/inode.c          | 2 +-
 fs/ubifs/super.c         | 2 +-
 fs/udf/super.c           | 2 +-
 fs/ufs/super.c           | 2 +-
 fs/vboxsf/super.c        | 2 +-
 fs/xfs/xfs_icache.c      | 3 ++-
 fs/zonefs/super.c        | 2 +-
 include/linux/fs.h       | 7 +++++++
 ipc/mqueue.c             | 2 +-
 mm/shmem.c               | 2 +-
 net/socket.c             | 2 +-
 net/sunrpc/rpc_pipe.c    | 2 +-
 59 files changed, 66 insertions(+), 58 deletions(-)

diff --git a/drivers/dax/super.c b/drivers/dax/super.c
index 5fa6ae9dbc8b..30474ba337c8 100644
--- a/drivers/dax/super.c
+++ b/drivers/dax/super.c
@@ -460,7 +460,7 @@ static struct inode *dax_alloc_inode(struct super_block *sb)
 	struct dax_device *dax_dev;
 	struct inode *inode;
 
-	dax_dev = kmem_cache_alloc(dax_cache, GFP_KERNEL);
+	dax_dev = alloc_inode_sb(sb, dax_cache, GFP_KERNEL);
 	if (!dax_dev)
 		return NULL;
 
diff --git a/fs/9p/vfs_inode.c b/fs/9p/vfs_inode.c
index 795706520b5e..5311f35accf5 100644
--- a/fs/9p/vfs_inode.c
+++ b/fs/9p/vfs_inode.c
@@ -223,7 +223,7 @@ v9fs_blank_wstat(struct p9_wstat *wstat)
 struct inode *v9fs_alloc_inode(struct super_block *sb)
 {
 	struct v9fs_inode *v9inode;
-	v9inode = kmem_cache_alloc(v9fs_inode_cache, GFP_KERNEL);
+	v9inode = alloc_inode_sb(sb, v9fs_inode_cache, GFP_KERNEL);
 	if (!v9inode)
 		return NULL;
 #ifdef CONFIG_9P_FSCACHE
diff --git a/fs/adfs/super.c b/fs/adfs/super.c
index bdbd26e571ed..e8bfc38239cd 100644
--- a/fs/adfs/super.c
+++ b/fs/adfs/super.c
@@ -220,7 +220,7 @@ static struct kmem_cache *adfs_inode_cachep;
 static struct inode *adfs_alloc_inode(struct super_block *sb)
 {
 	struct adfs_inode_info *ei;
-	ei = kmem_cache_alloc(adfs_inode_cachep, GFP_KERNEL);
+	ei = alloc_inode_sb(sb, adfs_inode_cachep, GFP_KERNEL);
 	if (!ei)
 		return NULL;
 	return &ei->vfs_inode;
diff --git a/fs/affs/super.c b/fs/affs/super.c
index c6c2a513ec92..67458f63a1ab 100644
--- a/fs/affs/super.c
+++ b/fs/affs/super.c
@@ -100,7 +100,7 @@ static struct inode *affs_alloc_inode(struct super_block *sb)
 {
 	struct affs_inode_info *i;
 
-	i = kmem_cache_alloc(affs_inode_cachep, GFP_KERNEL);
+	i = alloc_inode_sb(sb, affs_inode_cachep, GFP_KERNEL);
 	if (!i)
 		return NULL;
 
diff --git a/fs/afs/super.c b/fs/afs/super.c
index e38bb1e7a4d2..0ecea5a94af9 100644
--- a/fs/afs/super.c
+++ b/fs/afs/super.c
@@ -677,7 +677,7 @@ static struct inode *afs_alloc_inode(struct super_block *sb)
 {
 	struct afs_vnode *vnode;
 
-	vnode = kmem_cache_alloc(afs_inode_cachep, GFP_KERNEL);
+	vnode = alloc_inode_sb(sb, afs_inode_cachep, GFP_KERNEL);
 	if (!vnode)
 		return NULL;
 
diff --git a/fs/befs/linuxvfs.c b/fs/befs/linuxvfs.c
index c1ba13d19024..b4b3567ac655 100644
--- a/fs/befs/linuxvfs.c
+++ b/fs/befs/linuxvfs.c
@@ -277,7 +277,7 @@ befs_alloc_inode(struct super_block *sb)
 {
 	struct befs_inode_info *bi;
 
-	bi = kmem_cache_alloc(befs_inode_cachep, GFP_KERNEL);
+	bi = alloc_inode_sb(sb, befs_inode_cachep, GFP_KERNEL);
 	if (!bi)
 		return NULL;
 	return &bi->vfs_inode;
diff --git a/fs/bfs/inode.c b/fs/bfs/inode.c
index fd691e4815c5..1926bec2c850 100644
--- a/fs/bfs/inode.c
+++ b/fs/bfs/inode.c
@@ -239,7 +239,7 @@ static struct kmem_cache *bfs_inode_cachep;
 static struct inode *bfs_alloc_inode(struct super_block *sb)
 {
 	struct bfs_inode_info *bi;
-	bi = kmem_cache_alloc(bfs_inode_cachep, GFP_KERNEL);
+	bi = alloc_inode_sb(sb, bfs_inode_cachep, GFP_KERNEL);
 	if (!bi)
 		return NULL;
 	return &bi->vfs_inode;
diff --git a/fs/block_dev.c b/fs/block_dev.c
index 9114e0a0e7b4..4fc2ddb9e5ca 100644
--- a/fs/block_dev.c
+++ b/fs/block_dev.c
@@ -796,7 +796,7 @@ static struct kmem_cache * bdev_cachep __read_mostly;
 
 static struct inode *bdev_alloc_inode(struct super_block *sb)
 {
-	struct bdev_inode *ei = kmem_cache_alloc(bdev_cachep, GFP_KERNEL);
+	struct bdev_inode *ei = alloc_inode_sb(sb, bdev_cachep, GFP_KERNEL);
 
 	if (!ei)
 		return NULL;
diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c
index 4af336008b12..2262f58c0179 100644
--- a/fs/btrfs/inode.c
+++ b/fs/btrfs/inode.c
@@ -8830,7 +8830,7 @@ struct inode *btrfs_alloc_inode(struct super_block *sb)
 	struct btrfs_inode *ei;
 	struct inode *inode;
 
-	ei = kmem_cache_alloc(btrfs_inode_cachep, GFP_KERNEL);
+	ei = alloc_inode_sb(sb, btrfs_inode_cachep, GFP_KERNEL);
 	if (!ei)
 		return NULL;
 
diff --git a/fs/ceph/inode.c b/fs/ceph/inode.c
index 689e3ffd29d7..d5e95b524293 100644
--- a/fs/ceph/inode.c
+++ b/fs/ceph/inode.c
@@ -443,7 +443,7 @@ struct inode *ceph_alloc_inode(struct super_block *sb)
 	struct ceph_inode_info *ci;
 	int i;
 
-	ci = kmem_cache_alloc(ceph_inode_cachep, GFP_NOFS);
+	ci = alloc_inode_sb(sb, ceph_inode_cachep, GFP_NOFS);
 	if (!ci)
 		return NULL;
 
diff --git a/fs/cifs/cifsfs.c b/fs/cifs/cifsfs.c
index e0c5e860a0ee..7cd5c389fbf9 100644
--- a/fs/cifs/cifsfs.c
+++ b/fs/cifs/cifsfs.c
@@ -360,7 +360,7 @@ static struct inode *
 cifs_alloc_inode(struct super_block *sb)
 {
 	struct cifsInodeInfo *cifs_inode;
-	cifs_inode = kmem_cache_alloc(cifs_inode_cachep, GFP_KERNEL);
+	cifs_inode = alloc_inode_sb(sb, cifs_inode_cachep, GFP_KERNEL);
 	if (!cifs_inode)
 		return NULL;
 	cifs_inode->cifsAttrs = 0x20;	/* default */
diff --git a/fs/coda/inode.c b/fs/coda/inode.c
index d9f1bd7153df..2185328b65c7 100644
--- a/fs/coda/inode.c
+++ b/fs/coda/inode.c
@@ -43,7 +43,7 @@ static struct kmem_cache * coda_inode_cachep;
 static struct inode *coda_alloc_inode(struct super_block *sb)
 {
 	struct coda_inode_info *ei;
-	ei = kmem_cache_alloc(coda_inode_cachep, GFP_KERNEL);
+	ei = alloc_inode_sb(sb, coda_inode_cachep, GFP_KERNEL);
 	if (!ei)
 		return NULL;
 	memset(&ei->c_fid, 0, sizeof(struct CodaFid));
diff --git a/fs/ecryptfs/super.c b/fs/ecryptfs/super.c
index 39116af0390f..0b1c878317ab 100644
--- a/fs/ecryptfs/super.c
+++ b/fs/ecryptfs/super.c
@@ -38,7 +38,7 @@ static struct inode *ecryptfs_alloc_inode(struct super_block *sb)
 	struct ecryptfs_inode_info *inode_info;
 	struct inode *inode = NULL;
 
-	inode_info = kmem_cache_alloc(ecryptfs_inode_info_cache, GFP_KERNEL);
+	inode_info = alloc_inode_sb(sb, ecryptfs_inode_info_cache, GFP_KERNEL);
 	if (unlikely(!inode_info))
 		goto out;
 	if (ecryptfs_init_crypt_stat(&inode_info->crypt_stat)) {
diff --git a/fs/efs/super.c b/fs/efs/super.c
index 62b155b9366b..b287f47c165b 100644
--- a/fs/efs/super.c
+++ b/fs/efs/super.c
@@ -69,7 +69,7 @@ static struct kmem_cache * efs_inode_cachep;
 static struct inode *efs_alloc_inode(struct super_block *sb)
 {
 	struct efs_inode_info *ei;
-	ei = kmem_cache_alloc(efs_inode_cachep, GFP_KERNEL);
+	ei = alloc_inode_sb(sb, efs_inode_cachep, GFP_KERNEL);
 	if (!ei)
 		return NULL;
 	return &ei->vfs_inode;
diff --git a/fs/erofs/super.c b/fs/erofs/super.c
index bbf3bbd908e0..03f2dd684f8d 100644
--- a/fs/erofs/super.c
+++ b/fs/erofs/super.c
@@ -83,7 +83,7 @@ static void erofs_inode_init_once(void *ptr)
 static struct inode *erofs_alloc_inode(struct super_block *sb)
 {
 	struct erofs_inode *vi =
-		kmem_cache_alloc(erofs_inode_cachep, GFP_KERNEL);
+		alloc_inode_sb(sb, erofs_inode_cachep, GFP_KERNEL);
 
 	if (!vi)
 		return NULL;
diff --git a/fs/exfat/super.c b/fs/exfat/super.c
index d38d17a77e76..c88e0f218df0 100644
--- a/fs/exfat/super.c
+++ b/fs/exfat/super.c
@@ -182,7 +182,7 @@ static struct inode *exfat_alloc_inode(struct super_block *sb)
 {
 	struct exfat_inode_info *ei;
 
-	ei = kmem_cache_alloc(exfat_inode_cachep, GFP_NOFS);
+	ei = alloc_inode_sb(sb, exfat_inode_cachep, GFP_NOFS);
 	if (!ei)
 		return NULL;
 
diff --git a/fs/ext2/super.c b/fs/ext2/super.c
index 21e09fbaa46f..7eba9d6fbdc6 100644
--- a/fs/ext2/super.c
+++ b/fs/ext2/super.c
@@ -180,7 +180,7 @@ static struct kmem_cache * ext2_inode_cachep;
 static struct inode *ext2_alloc_inode(struct super_block *sb)
 {
 	struct ext2_inode_info *ei;
-	ei = kmem_cache_alloc(ext2_inode_cachep, GFP_KERNEL);
+	ei = alloc_inode_sb(sb, ext2_inode_cachep, GFP_KERNEL);
 	if (!ei)
 		return NULL;
 	ei->i_block_alloc_info = NULL;
diff --git a/fs/ext4/super.c b/fs/ext4/super.c
index 7dc94f3e18e6..b2c486d224b4 100644
--- a/fs/ext4/super.c
+++ b/fs/ext4/super.c
@@ -1275,7 +1275,7 @@ static struct inode *ext4_alloc_inode(struct super_block *sb)
 {
 	struct ext4_inode_info *ei;
 
-	ei = kmem_cache_alloc(ext4_inode_cachep, GFP_NOFS);
+	ei = alloc_inode_sb(sb, ext4_inode_cachep, GFP_NOFS);
 	if (!ei)
 		return NULL;
 
diff --git a/fs/f2fs/super.c b/fs/f2fs/super.c
index 7d325bfaf65a..444134950ae4 100644
--- a/fs/f2fs/super.c
+++ b/fs/f2fs/super.c
@@ -1169,7 +1169,7 @@ static struct inode *f2fs_alloc_inode(struct super_block *sb)
 {
 	struct f2fs_inode_info *fi;
 
-	fi = kmem_cache_alloc(f2fs_inode_cachep, GFP_F2FS_ZERO);
+	fi = alloc_inode_sb(sb, f2fs_inode_cachep, GFP_F2FS_ZERO);
 	if (!fi)
 		return NULL;
 
diff --git a/fs/fat/inode.c b/fs/fat/inode.c
index bab9b202b496..adc8a525553a 100644
--- a/fs/fat/inode.c
+++ b/fs/fat/inode.c
@@ -744,7 +744,7 @@ static struct kmem_cache *fat_inode_cachep;
 static struct inode *fat_alloc_inode(struct super_block *sb)
 {
 	struct msdos_inode_info *ei;
-	ei = kmem_cache_alloc(fat_inode_cachep, GFP_NOFS);
+	ei = alloc_inode_sb(sb, fat_inode_cachep, GFP_NOFS);
 	if (!ei)
 		return NULL;
 
diff --git a/fs/freevxfs/vxfs_super.c b/fs/freevxfs/vxfs_super.c
index 578a5062706e..22eed5a73ac2 100644
--- a/fs/freevxfs/vxfs_super.c
+++ b/fs/freevxfs/vxfs_super.c
@@ -124,7 +124,7 @@ static struct inode *vxfs_alloc_inode(struct super_block *sb)
 {
 	struct vxfs_inode_info *vi;
 
-	vi = kmem_cache_alloc(vxfs_inode_cachep, GFP_KERNEL);
+	vi = alloc_inode_sb(sb, vxfs_inode_cachep, GFP_KERNEL);
 	if (!vi)
 		return NULL;
 	inode_init_once(&vi->vfs_inode);
diff --git a/fs/fuse/inode.c b/fs/fuse/inode.c
index 393e36b74dc4..3fe7d1484ae6 100644
--- a/fs/fuse/inode.c
+++ b/fs/fuse/inode.c
@@ -73,7 +73,7 @@ static struct inode *fuse_alloc_inode(struct super_block *sb)
 {
 	struct fuse_inode *fi;
 
-	fi = kmem_cache_alloc(fuse_inode_cachep, GFP_KERNEL);
+	fi = alloc_inode_sb(sb, fuse_inode_cachep, GFP_KERNEL);
 	if (!fi)
 		return NULL;
 
diff --git a/fs/gfs2/super.c b/fs/gfs2/super.c
index 4d4ceb0b6903..e9e8ad6f0c66 100644
--- a/fs/gfs2/super.c
+++ b/fs/gfs2/super.c
@@ -1496,7 +1496,7 @@ static struct inode *gfs2_alloc_inode(struct super_block *sb)
 {
 	struct gfs2_inode *ip;
 
-	ip = kmem_cache_alloc(gfs2_inode_cachep, GFP_KERNEL);
+	ip = alloc_inode_sb(sb, gfs2_inode_cachep, GFP_KERNEL);
 	if (!ip)
 		return NULL;
 	ip->i_flags = 0;
diff --git a/fs/hfs/super.c b/fs/hfs/super.c
index 44d07c9e3a7f..e40334c93183 100644
--- a/fs/hfs/super.c
+++ b/fs/hfs/super.c
@@ -162,7 +162,7 @@ static struct inode *hfs_alloc_inode(struct super_block *sb)
 {
 	struct hfs_inode_info *i;
 
-	i = kmem_cache_alloc(hfs_inode_cachep, GFP_KERNEL);
+	i = alloc_inode_sb(sb, hfs_inode_cachep, GFP_KERNEL);
 	return i ? &i->vfs_inode : NULL;
 }
 
diff --git a/fs/hfsplus/super.c b/fs/hfsplus/super.c
index b9e3db3f855f..8479add998b5 100644
--- a/fs/hfsplus/super.c
+++ b/fs/hfsplus/super.c
@@ -624,7 +624,7 @@ static struct inode *hfsplus_alloc_inode(struct super_block *sb)
 {
 	struct hfsplus_inode_info *i;
 
-	i = kmem_cache_alloc(hfsplus_inode_cachep, GFP_KERNEL);
+	i = alloc_inode_sb(sb, hfsplus_inode_cachep, GFP_KERNEL);
 	return i ? &i->vfs_inode : NULL;
 }
 
diff --git a/fs/hostfs/hostfs_kern.c b/fs/hostfs/hostfs_kern.c
index 7d0c3dbb2898..96dc97ae48e4 100644
--- a/fs/hostfs/hostfs_kern.c
+++ b/fs/hostfs/hostfs_kern.c
@@ -222,7 +222,7 @@ static struct inode *hostfs_alloc_inode(struct super_block *sb)
 {
 	struct hostfs_inode_info *hi;
 
-	hi = kmem_cache_alloc(hostfs_inode_cache, GFP_KERNEL_ACCOUNT);
+	hi = alloc_inode_sb(sb, hostfs_inode_cache, GFP_KERNEL_ACCOUNT);
 	if (hi == NULL)
 		return NULL;
 	hi->fd = -1;
diff --git a/fs/hpfs/super.c b/fs/hpfs/super.c
index a7dbfc892022..1cb89595b875 100644
--- a/fs/hpfs/super.c
+++ b/fs/hpfs/super.c
@@ -232,7 +232,7 @@ static struct kmem_cache * hpfs_inode_cachep;
 static struct inode *hpfs_alloc_inode(struct super_block *sb)
 {
 	struct hpfs_inode_info *ei;
-	ei = kmem_cache_alloc(hpfs_inode_cachep, GFP_NOFS);
+	ei = alloc_inode_sb(sb, hpfs_inode_cachep, GFP_NOFS);
 	if (!ei)
 		return NULL;
 	return &ei->vfs_inode;
diff --git a/fs/hugetlbfs/inode.c b/fs/hugetlbfs/inode.c
index a2a42335e8fd..1403b4bd6514 100644
--- a/fs/hugetlbfs/inode.c
+++ b/fs/hugetlbfs/inode.c
@@ -1103,7 +1103,7 @@ static struct inode *hugetlbfs_alloc_inode(struct super_block *sb)
 
 	if (unlikely(!hugetlbfs_dec_free_inodes(sbinfo)))
 		return NULL;
-	p = kmem_cache_alloc(hugetlbfs_inode_cachep, GFP_KERNEL);
+	p = alloc_inode_sb(sb, hugetlbfs_inode_cachep, GFP_KERNEL);
 	if (unlikely(!p)) {
 		hugetlbfs_inc_free_inodes(sbinfo);
 		return NULL;
diff --git a/fs/inode.c b/fs/inode.c
index af48d1b722f0..68b9167ad18b 100644
--- a/fs/inode.c
+++ b/fs/inode.c
@@ -232,7 +232,7 @@ static struct inode *alloc_inode(struct super_block *sb)
 	if (ops->alloc_inode)
 		inode = ops->alloc_inode(sb);
 	else
-		inode = kmem_cache_alloc(inode_cachep, GFP_KERNEL);
+		inode = alloc_inode_sb(sb, inode_cachep, GFP_KERNEL);
 
 	if (!inode)
 		return NULL;
diff --git a/fs/isofs/inode.c b/fs/isofs/inode.c
index 21edc423b79f..ef6c29501702 100644
--- a/fs/isofs/inode.c
+++ b/fs/isofs/inode.c
@@ -70,7 +70,7 @@ static struct kmem_cache *isofs_inode_cachep;
 static struct inode *isofs_alloc_inode(struct super_block *sb)
 {
 	struct iso_inode_info *ei;
-	ei = kmem_cache_alloc(isofs_inode_cachep, GFP_KERNEL);
+	ei = alloc_inode_sb(sb, isofs_inode_cachep, GFP_KERNEL);
 	if (!ei)
 		return NULL;
 	return &ei->vfs_inode;
diff --git a/fs/jffs2/super.c b/fs/jffs2/super.c
index 81ca58c10b72..7ea37f49f1e1 100644
--- a/fs/jffs2/super.c
+++ b/fs/jffs2/super.c
@@ -39,7 +39,7 @@ static struct inode *jffs2_alloc_inode(struct super_block *sb)
 {
 	struct jffs2_inode_info *f;
 
-	f = kmem_cache_alloc(jffs2_inode_cachep, GFP_KERNEL);
+	f = alloc_inode_sb(sb, jffs2_inode_cachep, GFP_KERNEL);
 	if (!f)
 		return NULL;
 	return &f->vfs_inode;
diff --git a/fs/jfs/super.c b/fs/jfs/super.c
index 1f0ffabbde56..65255541d44e 100644
--- a/fs/jfs/super.c
+++ b/fs/jfs/super.c
@@ -102,7 +102,7 @@ static struct inode *jfs_alloc_inode(struct super_block *sb)
 {
 	struct jfs_inode_info *jfs_inode;
 
-	jfs_inode = kmem_cache_alloc(jfs_inode_cachep, GFP_NOFS);
+	jfs_inode = alloc_inode_sb(sb, jfs_inode_cachep, GFP_NOFS);
 	if (!jfs_inode)
 		return NULL;
 #ifdef CONFIG_QUOTA
diff --git a/fs/minix/inode.c b/fs/minix/inode.c
index a532a99bbe81..f30b1daac386 100644
--- a/fs/minix/inode.c
+++ b/fs/minix/inode.c
@@ -63,7 +63,7 @@ static struct kmem_cache * minix_inode_cachep;
 static struct inode *minix_alloc_inode(struct super_block *sb)
 {
 	struct minix_inode_info *ei;
-	ei = kmem_cache_alloc(minix_inode_cachep, GFP_KERNEL);
+	ei = alloc_inode_sb(sb, minix_inode_cachep, GFP_KERNEL);
 	if (!ei)
 		return NULL;
 	return &ei->vfs_inode;
diff --git a/fs/nfs/inode.c b/fs/nfs/inode.c
index 529c4099f482..fa3d8e8b695f 100644
--- a/fs/nfs/inode.c
+++ b/fs/nfs/inode.c
@@ -2240,7 +2240,7 @@ static int nfs_update_inode(struct inode *inode, struct nfs_fattr *fattr)
 struct inode *nfs_alloc_inode(struct super_block *sb)
 {
 	struct nfs_inode *nfsi;
-	nfsi = kmem_cache_alloc(nfs_inode_cachep, GFP_KERNEL);
+	nfsi = alloc_inode_sb(sb, nfs_inode_cachep, GFP_KERNEL);
 	if (!nfsi)
 		return NULL;
 	nfsi->flags = 0UL;
diff --git a/fs/nilfs2/super.c b/fs/nilfs2/super.c
index 4abd928b0bc8..e7d7ad7a1e50 100644
--- a/fs/nilfs2/super.c
+++ b/fs/nilfs2/super.c
@@ -151,7 +151,7 @@ struct inode *nilfs_alloc_inode(struct super_block *sb)
 {
 	struct nilfs_inode_info *ii;
 
-	ii = kmem_cache_alloc(nilfs_inode_cachep, GFP_NOFS);
+	ii = alloc_inode_sb(sb, nilfs_inode_cachep, GFP_NOFS);
 	if (!ii)
 		return NULL;
 	ii->i_bh = NULL;
diff --git a/fs/ntfs/inode.c b/fs/ntfs/inode.c
index f5c058b3192c..1e053bb58ead 100644
--- a/fs/ntfs/inode.c
+++ b/fs/ntfs/inode.c
@@ -310,7 +310,7 @@ struct inode *ntfs_alloc_big_inode(struct super_block *sb)
 	ntfs_inode *ni;
 
 	ntfs_debug("Entering.");
-	ni = kmem_cache_alloc(ntfs_big_inode_cache, GFP_NOFS);
+	ni = alloc_inode_sb(sb, ntfs_big_inode_cache, GFP_NOFS);
 	if (likely(ni != NULL)) {
 		ni->state = 0;
 		return VFS_I(ni);
diff --git a/fs/ocfs2/dlmfs/dlmfs.c b/fs/ocfs2/dlmfs/dlmfs.c
index fa0a14f199eb..e360543ad7e7 100644
--- a/fs/ocfs2/dlmfs/dlmfs.c
+++ b/fs/ocfs2/dlmfs/dlmfs.c
@@ -280,7 +280,7 @@ static struct inode *dlmfs_alloc_inode(struct super_block *sb)
 {
 	struct dlmfs_inode_private *ip;
 
-	ip = kmem_cache_alloc(dlmfs_inode_cache, GFP_NOFS);
+	ip = alloc_inode_sb(sb, dlmfs_inode_cache, GFP_NOFS);
 	if (!ip)
 		return NULL;
 
diff --git a/fs/ocfs2/super.c b/fs/ocfs2/super.c
index c86bd4e60e20..cf044448130f 100644
--- a/fs/ocfs2/super.c
+++ b/fs/ocfs2/super.c
@@ -549,7 +549,7 @@ static struct inode *ocfs2_alloc_inode(struct super_block *sb)
 {
 	struct ocfs2_inode_info *oi;
 
-	oi = kmem_cache_alloc(ocfs2_inode_cachep, GFP_NOFS);
+	oi = alloc_inode_sb(sb, ocfs2_inode_cachep, GFP_NOFS);
 	if (!oi)
 		return NULL;
 
diff --git a/fs/openpromfs/inode.c b/fs/openpromfs/inode.c
index f825176ff4ed..f0b7f4d51a17 100644
--- a/fs/openpromfs/inode.c
+++ b/fs/openpromfs/inode.c
@@ -335,7 +335,7 @@ static struct inode *openprom_alloc_inode(struct super_block *sb)
 {
 	struct op_inode_info *oi;
 
-	oi = kmem_cache_alloc(op_inode_cachep, GFP_KERNEL);
+	oi = alloc_inode_sb(sb, op_inode_cachep, GFP_KERNEL);
 	if (!oi)
 		return NULL;
 
diff --git a/fs/orangefs/super.c b/fs/orangefs/super.c
index ee5efdc35cc1..5731ce285c98 100644
--- a/fs/orangefs/super.c
+++ b/fs/orangefs/super.c
@@ -106,7 +106,7 @@ static struct inode *orangefs_alloc_inode(struct super_block *sb)
 {
 	struct orangefs_inode_s *orangefs_inode;
 
-	orangefs_inode = kmem_cache_alloc(orangefs_inode_cache, GFP_KERNEL);
+	orangefs_inode = alloc_inode_sb(sb, orangefs_inode_cache, GFP_KERNEL);
 	if (!orangefs_inode)
 		return NULL;
 
diff --git a/fs/overlayfs/super.c b/fs/overlayfs/super.c
index b01d4147520d..6d8d16bf4b57 100644
--- a/fs/overlayfs/super.c
+++ b/fs/overlayfs/super.c
@@ -174,7 +174,7 @@ static struct kmem_cache *ovl_inode_cachep;
 
 static struct inode *ovl_alloc_inode(struct super_block *sb)
 {
-	struct ovl_inode *oi = kmem_cache_alloc(ovl_inode_cachep, GFP_KERNEL);
+	struct ovl_inode *oi = alloc_inode_sb(sb, ovl_inode_cachep, GFP_KERNEL);
 
 	if (!oi)
 		return NULL;
diff --git a/fs/proc/inode.c b/fs/proc/inode.c
index 599eb724ff2d..cc0a406d3a19 100644
--- a/fs/proc/inode.c
+++ b/fs/proc/inode.c
@@ -66,7 +66,7 @@ static struct inode *proc_alloc_inode(struct super_block *sb)
 {
 	struct proc_inode *ei;
 
-	ei = kmem_cache_alloc(proc_inode_cachep, GFP_KERNEL);
+	ei = alloc_inode_sb(sb, proc_inode_cachep, GFP_KERNEL);
 	if (!ei)
 		return NULL;
 	ei->pid = NULL;
diff --git a/fs/qnx4/inode.c b/fs/qnx4/inode.c
index 3fb7fc819b4f..a635bb6615e9 100644
--- a/fs/qnx4/inode.c
+++ b/fs/qnx4/inode.c
@@ -338,7 +338,7 @@ static struct kmem_cache *qnx4_inode_cachep;
 static struct inode *qnx4_alloc_inode(struct super_block *sb)
 {
 	struct qnx4_inode_info *ei;
-	ei = kmem_cache_alloc(qnx4_inode_cachep, GFP_KERNEL);
+	ei = alloc_inode_sb(sb, qnx4_inode_cachep, GFP_KERNEL);
 	if (!ei)
 		return NULL;
 	return &ei->vfs_inode;
diff --git a/fs/qnx6/inode.c b/fs/qnx6/inode.c
index 61191f7bdf62..9d8e7e9788a1 100644
--- a/fs/qnx6/inode.c
+++ b/fs/qnx6/inode.c
@@ -597,7 +597,7 @@ static struct kmem_cache *qnx6_inode_cachep;
 static struct inode *qnx6_alloc_inode(struct super_block *sb)
 {
 	struct qnx6_inode_info *ei;
-	ei = kmem_cache_alloc(qnx6_inode_cachep, GFP_KERNEL);
+	ei = alloc_inode_sb(sb, qnx6_inode_cachep, GFP_KERNEL);
 	if (!ei)
 		return NULL;
 	return &ei->vfs_inode;
diff --git a/fs/reiserfs/super.c b/fs/reiserfs/super.c
index 3ffafc73acf0..d9e8b0368ce9 100644
--- a/fs/reiserfs/super.c
+++ b/fs/reiserfs/super.c
@@ -639,7 +639,7 @@ static struct kmem_cache *reiserfs_inode_cachep;
 static struct inode *reiserfs_alloc_inode(struct super_block *sb)
 {
 	struct reiserfs_inode_info *ei;
-	ei = kmem_cache_alloc(reiserfs_inode_cachep, GFP_KERNEL);
+	ei = alloc_inode_sb(sb, reiserfs_inode_cachep, GFP_KERNEL);
 	if (!ei)
 		return NULL;
 	atomic_set(&ei->openers, 0);
diff --git a/fs/romfs/super.c b/fs/romfs/super.c
index 259f684d9236..9e6bbb4219de 100644
--- a/fs/romfs/super.c
+++ b/fs/romfs/super.c
@@ -375,7 +375,7 @@ static struct inode *romfs_alloc_inode(struct super_block *sb)
 {
 	struct romfs_inode_info *inode;
 
-	inode = kmem_cache_alloc(romfs_inode_cachep, GFP_KERNEL);
+	inode = alloc_inode_sb(sb, romfs_inode_cachep, GFP_KERNEL);
 	return inode ? &inode->vfs_inode : NULL;
 }
 
diff --git a/fs/squashfs/super.c b/fs/squashfs/super.c
index 88cc94be1076..16b785cb78c4 100644
--- a/fs/squashfs/super.c
+++ b/fs/squashfs/super.c
@@ -466,7 +466,7 @@ static void __exit exit_squashfs_fs(void)
 static struct inode *squashfs_alloc_inode(struct super_block *sb)
 {
 	struct squashfs_inode_info *ei =
-		kmem_cache_alloc(squashfs_inode_cachep, GFP_KERNEL);
+		alloc_inode_sb(sb, squashfs_inode_cachep, GFP_KERNEL);
 
 	return ei ? &ei->vfs_inode : NULL;
 }
diff --git a/fs/sysv/inode.c b/fs/sysv/inode.c
index be47263b8605..9e8d4a6fb2f3 100644
--- a/fs/sysv/inode.c
+++ b/fs/sysv/inode.c
@@ -306,7 +306,7 @@ static struct inode *sysv_alloc_inode(struct super_block *sb)
 {
 	struct sysv_inode_info *si;
 
-	si = kmem_cache_alloc(sysv_inode_cachep, GFP_KERNEL);
+	si = alloc_inode_sb(sb, sysv_inode_cachep, GFP_KERNEL);
 	if (!si)
 		return NULL;
 	return &si->vfs_inode;
diff --git a/fs/ubifs/super.c b/fs/ubifs/super.c
index 7b572e1414ba..6851040c598e 100644
--- a/fs/ubifs/super.c
+++ b/fs/ubifs/super.c
@@ -268,7 +268,7 @@ static struct inode *ubifs_alloc_inode(struct super_block *sb)
 {
 	struct ubifs_inode *ui;
 
-	ui = kmem_cache_alloc(ubifs_inode_slab, GFP_NOFS);
+	ui = alloc_inode_sb(sb, ubifs_inode_slab, GFP_NOFS);
 	if (!ui)
 		return NULL;
 
diff --git a/fs/udf/super.c b/fs/udf/super.c
index 2f83c1204e20..bdeaa5d88a9e 100644
--- a/fs/udf/super.c
+++ b/fs/udf/super.c
@@ -141,7 +141,7 @@ static struct kmem_cache *udf_inode_cachep;
 static struct inode *udf_alloc_inode(struct super_block *sb)
 {
 	struct udf_inode_info *ei;
-	ei = kmem_cache_alloc(udf_inode_cachep, GFP_KERNEL);
+	ei = alloc_inode_sb(sb, udf_inode_cachep, GFP_KERNEL);
 	if (!ei)
 		return NULL;
 
diff --git a/fs/ufs/super.c b/fs/ufs/super.c
index 74028b5a7b0a..ba83ad6e9d39 100644
--- a/fs/ufs/super.c
+++ b/fs/ufs/super.c
@@ -1443,7 +1443,7 @@ static struct inode *ufs_alloc_inode(struct super_block *sb)
 {
 	struct ufs_inode_info *ei;
 
-	ei = kmem_cache_alloc(ufs_inode_cachep, GFP_NOFS);
+	ei = alloc_inode_sb(sb, ufs_inode_cachep, GFP_NOFS);
 	if (!ei)
 		return NULL;
 
diff --git a/fs/vboxsf/super.c b/fs/vboxsf/super.c
index 4f5e59f06284..050ef855158b 100644
--- a/fs/vboxsf/super.c
+++ b/fs/vboxsf/super.c
@@ -244,7 +244,7 @@ static struct inode *vboxsf_alloc_inode(struct super_block *sb)
 {
 	struct vboxsf_inode *sf_i;
 
-	sf_i = kmem_cache_alloc(vboxsf_inode_cachep, GFP_NOFS);
+	sf_i = alloc_inode_sb(sb, vboxsf_inode_cachep, GFP_NOFS);
 	if (!sf_i)
 		return NULL;
 
diff --git a/fs/xfs/xfs_icache.c b/fs/xfs/xfs_icache.c
index 3c81daca0e9a..8c8b059e1e26 100644
--- a/fs/xfs/xfs_icache.c
+++ b/fs/xfs/xfs_icache.c
@@ -40,7 +40,8 @@ xfs_inode_alloc(
 	 * XXX: If this didn't occur in transactions, we could drop GFP_NOFAIL
 	 * and return NULL here on ENOMEM.
 	 */
-	ip = kmem_cache_alloc(xfs_inode_zone, GFP_KERNEL | __GFP_NOFAIL);
+	ip = alloc_inode_sb(mp->m_super, xfs_inode_zone,
+			    GFP_KERNEL | __GFP_NOFAIL);
 
 	if (inode_init_always(mp->m_super, VFS_I(ip))) {
 		kmem_cache_free(xfs_inode_zone, ip);
diff --git a/fs/zonefs/super.c b/fs/zonefs/super.c
index cd145d318b17..335b58251b52 100644
--- a/fs/zonefs/super.c
+++ b/fs/zonefs/super.c
@@ -1152,7 +1152,7 @@ static struct inode *zonefs_alloc_inode(struct super_block *sb)
 {
 	struct zonefs_inode_info *zi;
 
-	zi = kmem_cache_alloc(zonefs_inode_cachep, GFP_KERNEL);
+	zi = alloc_inode_sb(sb, zonefs_inode_cachep, GFP_KERNEL);
 	if (!zi)
 		return NULL;
 
diff --git a/include/linux/fs.h b/include/linux/fs.h
index c3c88fdb9b2a..d8d5d4eb68d6 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -41,6 +41,7 @@
 #include <linux/stddef.h>
 #include <linux/mount.h>
 #include <linux/cred.h>
+#include <linux/slab.h>
 
 #include <asm/byteorder.h>
 #include <uapi/linux/fs.h>
@@ -3200,6 +3201,12 @@ extern void free_inode_nonrcu(struct inode *inode);
 extern int should_remove_suid(struct dentry *);
 extern int file_remove_privs(struct file *);
 
+static inline void *
+alloc_inode_sb(struct super_block *sb, struct kmem_cache *cache, gfp_t gfp)
+{
+	return kmem_cache_alloc_lru(cache, &sb->s_inode_lru, gfp);
+}
+
 extern void __insert_inode_hash(struct inode *, unsigned long hashval);
 static inline void insert_inode_hash(struct inode *inode)
 {
diff --git a/ipc/mqueue.c b/ipc/mqueue.c
index 8031464ed4ae..815d7289bf93 100644
--- a/ipc/mqueue.c
+++ b/ipc/mqueue.c
@@ -483,7 +483,7 @@ static struct inode *mqueue_alloc_inode(struct super_block *sb)
 {
 	struct mqueue_inode_info *ei;
 
-	ei = kmem_cache_alloc(mqueue_inode_cachep, GFP_KERNEL);
+	ei = alloc_inode_sb(sb, mqueue_inode_cachep, GFP_KERNEL);
 	if (!ei)
 		return NULL;
 	return &ei->vfs_inode;
diff --git a/mm/shmem.c b/mm/shmem.c
index a08cedefbfaa..dad27ca340ef 100644
--- a/mm/shmem.c
+++ b/mm/shmem.c
@@ -3772,7 +3772,7 @@ static struct kmem_cache *shmem_inode_cachep;
 static struct inode *shmem_alloc_inode(struct super_block *sb)
 {
 	struct shmem_inode_info *info;
-	info = kmem_cache_alloc(shmem_inode_cachep, GFP_KERNEL);
+	info = alloc_inode_sb(sb, shmem_inode_cachep, GFP_KERNEL);
 	if (!info)
 		return NULL;
 	return &info->vfs_inode;
diff --git a/net/socket.c b/net/socket.c
index 27e3e7d53f8e..d59844b02a2d 100644
--- a/net/socket.c
+++ b/net/socket.c
@@ -250,7 +250,7 @@ static struct inode *sock_alloc_inode(struct super_block *sb)
 {
 	struct socket_alloc *ei;
 
-	ei = kmem_cache_alloc(sock_inode_cachep, GFP_KERNEL);
+	ei = alloc_inode_sb(sb, sock_inode_cachep, GFP_KERNEL);
 	if (!ei)
 		return NULL;
 	init_waitqueue_head(&ei->socket.wq.wait);
diff --git a/net/sunrpc/rpc_pipe.c b/net/sunrpc/rpc_pipe.c
index 09c000d490a1..30707f39694e 100644
--- a/net/sunrpc/rpc_pipe.c
+++ b/net/sunrpc/rpc_pipe.c
@@ -197,7 +197,7 @@ static struct inode *
 rpc_alloc_inode(struct super_block *sb)
 {
 	struct rpc_inode *rpci;
-	rpci = kmem_cache_alloc(rpc_inode_cachep, GFP_KERNEL);
+	rpci = alloc_inode_sb(sb, rpc_inode_cachep, GFP_KERNEL);
 	if (!rpci)
 		return NULL;
 	return &rpci->vfs_inode;
-- 
2.11.0


^ permalink raw reply	[flat|nested] 20+ messages in thread

* [PATCH 11/17] mm: dcache: use kmem_cache_alloc_lru() to allocate dentry
  2021-05-11 10:46 [PATCH 00/17] Optimize list lru memory consumption Muchun Song
                   ` (9 preceding siblings ...)
  2021-05-11 10:46 ` [PATCH 10/17] fs: introduce alloc_inode_sb() to allocate filesystems specific inode Muchun Song
@ 2021-05-11 10:46 ` Muchun Song
  2021-05-11 10:46 ` [PATCH 12/17] xarray: replace kmem_cache_alloc with kmem_cache_alloc_lru Muchun Song
                   ` (5 subsequent siblings)
  16 siblings, 0 replies; 20+ messages in thread
From: Muchun Song @ 2021-05-11 10:46 UTC (permalink / raw)
  To: willy, akpm, hannes, mhocko, vdavydov.dev, shakeelb, guro,
	shy828301, alexs, richard.weiyang, david, trond.myklebust,
	anna.schumaker
  Cc: linux-fsdevel, linux-kernel, linux-mm, linux-nfs, zhengqi.arch,
	duanxiongchun, fam.zheng, Muchun Song

The dentry will be added to its list_lru, so we should also allocate the
lru list. Replace kmem_cache_alloc() with kmem_cache_alloc_lru().

Signed-off-by: Muchun Song <songmuchun@bytedance.com>
---
 fs/dcache.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/fs/dcache.c b/fs/dcache.c
index cf871a81f4fd..36d4806d7284 100644
--- a/fs/dcache.c
+++ b/fs/dcache.c
@@ -1741,7 +1741,8 @@ static struct dentry *__d_alloc(struct super_block *sb, const struct qstr *name)
 	char *dname;
 	int err;
 
-	dentry = kmem_cache_alloc(dentry_cache, GFP_KERNEL);
+	dentry = kmem_cache_alloc_lru(dentry_cache, &sb->s_dentry_lru,
+				      GFP_KERNEL);
 	if (!dentry)
 		return NULL;
 
-- 
2.11.0


^ permalink raw reply	[flat|nested] 20+ messages in thread

* [PATCH 12/17] xarray: replace kmem_cache_alloc with kmem_cache_alloc_lru
  2021-05-11 10:46 [PATCH 00/17] Optimize list lru memory consumption Muchun Song
                   ` (10 preceding siblings ...)
  2021-05-11 10:46 ` [PATCH 11/17] mm: dcache: use kmem_cache_alloc_lru() to allocate dentry Muchun Song
@ 2021-05-11 10:46 ` Muchun Song
  2021-05-11 10:46 ` [PATCH 13/17] mm: workingset: allocate list_lru on xa_node allocation Muchun Song
                   ` (4 subsequent siblings)
  16 siblings, 0 replies; 20+ messages in thread
From: Muchun Song @ 2021-05-11 10:46 UTC (permalink / raw)
  To: willy, akpm, hannes, mhocko, vdavydov.dev, shakeelb, guro,
	shy828301, alexs, richard.weiyang, david, trond.myklebust,
	anna.schumaker
  Cc: linux-fsdevel, linux-kernel, linux-mm, linux-nfs, zhengqi.arch,
	duanxiongchun, fam.zheng, Muchun Song

The workingset will add the xa_node to the shadow_nodes list. So the
allocation of xa_node should be done by kmem_cache_alloc_lru(). The
user of the xarray can xas_set_lru() to pass the list_lru.

Signed-off-by: Muchun Song <songmuchun@bytedance.com>
---
 include/linux/xarray.h |  9 ++++++++-
 lib/xarray.c           | 10 +++++-----
 2 files changed, 13 insertions(+), 6 deletions(-)

diff --git a/include/linux/xarray.h b/include/linux/xarray.h
index a91e3d90df8a..31f3e5ef3c7b 100644
--- a/include/linux/xarray.h
+++ b/include/linux/xarray.h
@@ -1317,6 +1317,7 @@ struct xa_state {
 	struct xa_node *xa_node;
 	struct xa_node *xa_alloc;
 	xa_update_node_t xa_update;
+	struct list_lru *xa_lru;
 };
 
 /*
@@ -1336,7 +1337,8 @@ struct xa_state {
 	.xa_pad = 0,					\
 	.xa_node = XAS_RESTART,				\
 	.xa_alloc = NULL,				\
-	.xa_update = NULL				\
+	.xa_update = NULL,				\
+	.xa_lru = NULL,					\
 }
 
 /**
@@ -1613,6 +1615,11 @@ static inline void xas_set_update(struct xa_state *xas, xa_update_node_t update)
 	xas->xa_update = update;
 }
 
+static inline void xas_set_lru(struct xa_state *xas, struct list_lru *lru)
+{
+	xas->xa_lru = lru;
+}
+
 /**
  * xas_next_entry() - Advance iterator to next present entry.
  * @xas: XArray operation state.
diff --git a/lib/xarray.c b/lib/xarray.c
index f5d8f54907b4..e9b818abc823 100644
--- a/lib/xarray.c
+++ b/lib/xarray.c
@@ -302,7 +302,7 @@ bool xas_nomem(struct xa_state *xas, gfp_t gfp)
 	}
 	if (xas->xa->xa_flags & XA_FLAGS_ACCOUNT)
 		gfp |= __GFP_ACCOUNT;
-	xas->xa_alloc = kmem_cache_alloc(radix_tree_node_cachep, gfp);
+	xas->xa_alloc = kmem_cache_alloc_lru(radix_tree_node_cachep, xas->xa_lru, gfp);
 	if (!xas->xa_alloc)
 		return false;
 	xas->xa_alloc->parent = NULL;
@@ -334,10 +334,10 @@ static bool __xas_nomem(struct xa_state *xas, gfp_t gfp)
 		gfp |= __GFP_ACCOUNT;
 	if (gfpflags_allow_blocking(gfp)) {
 		xas_unlock_type(xas, lock_type);
-		xas->xa_alloc = kmem_cache_alloc(radix_tree_node_cachep, gfp);
+		xas->xa_alloc = kmem_cache_alloc_lru(radix_tree_node_cachep, xas->xa_lru, gfp);
 		xas_lock_type(xas, lock_type);
 	} else {
-		xas->xa_alloc = kmem_cache_alloc(radix_tree_node_cachep, gfp);
+		xas->xa_alloc = kmem_cache_alloc_lru(radix_tree_node_cachep, xas->xa_lru, gfp);
 	}
 	if (!xas->xa_alloc)
 		return false;
@@ -371,7 +371,7 @@ static void *xas_alloc(struct xa_state *xas, unsigned int shift)
 		if (xas->xa->xa_flags & XA_FLAGS_ACCOUNT)
 			gfp |= __GFP_ACCOUNT;
 
-		node = kmem_cache_alloc(radix_tree_node_cachep, gfp);
+		node = kmem_cache_alloc_lru(radix_tree_node_cachep, xas->xa_lru, gfp);
 		if (!node) {
 			xas_set_err(xas, -ENOMEM);
 			return NULL;
@@ -1014,7 +1014,7 @@ void xas_split_alloc(struct xa_state *xas, void *entry, unsigned int order,
 		void *sibling = NULL;
 		struct xa_node *node;
 
-		node = kmem_cache_alloc(radix_tree_node_cachep, gfp);
+		node = kmem_cache_alloc_lru(radix_tree_node_cachep, xas->xa_lru, gfp);
 		if (!node)
 			goto nomem;
 		node->array = xas->xa;
-- 
2.11.0


^ permalink raw reply	[flat|nested] 20+ messages in thread

* [PATCH 13/17] mm: workingset: allocate list_lru on xa_node allocation
  2021-05-11 10:46 [PATCH 00/17] Optimize list lru memory consumption Muchun Song
                   ` (11 preceding siblings ...)
  2021-05-11 10:46 ` [PATCH 12/17] xarray: replace kmem_cache_alloc with kmem_cache_alloc_lru Muchun Song
@ 2021-05-11 10:46 ` Muchun Song
  2021-05-11 10:46 ` [PATCH 14/17] nfs42: use a specific kmem_cache to allocate nfs4_xattr_entry Muchun Song
                   ` (3 subsequent siblings)
  16 siblings, 0 replies; 20+ messages in thread
From: Muchun Song @ 2021-05-11 10:46 UTC (permalink / raw)
  To: willy, akpm, hannes, mhocko, vdavydov.dev, shakeelb, guro,
	shy828301, alexs, richard.weiyang, david, trond.myklebust,
	anna.schumaker
  Cc: linux-fsdevel, linux-kernel, linux-mm, linux-nfs, zhengqi.arch,
	duanxiongchun, fam.zheng, Muchun Song

The workingset will add the xa_node to its list_lru, we should use
xas_set_lru() to pass which lru we want to insert.

Signed-off-by: Muchun Song <songmuchun@bytedance.com>
---
 include/linux/swap.h | 5 ++++-
 mm/workingset.c      | 2 +-
 2 files changed, 5 insertions(+), 2 deletions(-)

diff --git a/include/linux/swap.h b/include/linux/swap.h
index 144727041e78..a2418ebad13d 100644
--- a/include/linux/swap.h
+++ b/include/linux/swap.h
@@ -322,9 +322,12 @@ void workingset_activation(struct page *page);
 
 /* Only track the nodes of mappings with shadow entries */
 void workingset_update_node(struct xa_node *node);
+extern struct list_lru shadow_nodes;
 #define mapping_set_update(xas, mapping) do {				\
-	if (!dax_mapping(mapping) && !shmem_mapping(mapping))		\
+	if (!dax_mapping(mapping) && !shmem_mapping(mapping)) {		\
 		xas_set_update(xas, workingset_update_node);		\
+		xas_set_lru(xas, &shadow_nodes);			\
+	}								\
 } while (0)
 
 /* linux/mm/page_alloc.c */
diff --git a/mm/workingset.c b/mm/workingset.c
index b7cdeca5a76d..f6923865be47 100644
--- a/mm/workingset.c
+++ b/mm/workingset.c
@@ -426,7 +426,7 @@ void workingset_activation(struct page *page)
  * point where they would still be useful.
  */
 
-static struct list_lru shadow_nodes;
+struct list_lru shadow_nodes;
 
 void workingset_update_node(struct xa_node *node)
 {
-- 
2.11.0


^ permalink raw reply	[flat|nested] 20+ messages in thread

* [PATCH 14/17] nfs42: use a specific kmem_cache to allocate nfs4_xattr_entry
  2021-05-11 10:46 [PATCH 00/17] Optimize list lru memory consumption Muchun Song
                   ` (12 preceding siblings ...)
  2021-05-11 10:46 ` [PATCH 13/17] mm: workingset: allocate list_lru on xa_node allocation Muchun Song
@ 2021-05-11 10:46 ` Muchun Song
  2021-05-11 10:46 ` [PATCH 15/17] mm: list_lru: allocate list_lru_one only when needed Muchun Song
                   ` (2 subsequent siblings)
  16 siblings, 0 replies; 20+ messages in thread
From: Muchun Song @ 2021-05-11 10:46 UTC (permalink / raw)
  To: willy, akpm, hannes, mhocko, vdavydov.dev, shakeelb, guro,
	shy828301, alexs, richard.weiyang, david, trond.myklebust,
	anna.schumaker
  Cc: linux-fsdevel, linux-kernel, linux-mm, linux-nfs, zhengqi.arch,
	duanxiongchun, fam.zheng, Muchun Song

If we want to add the allocated objects to its list_lru, we should use
kmem_cache_alloc_lru() to allocate objects. So intruduce
nfs4_xattr_entry_cachep which is used to allocate nfs4_xattr_entry.

Signed-off-by: Muchun Song <songmuchun@bytedance.com>
---
 fs/nfs/nfs42xattr.c | 95 ++++++++++++++++++++++++++---------------------------
 1 file changed, 47 insertions(+), 48 deletions(-)

diff --git a/fs/nfs/nfs42xattr.c b/fs/nfs/nfs42xattr.c
index 1c4d2a05b401..5b7af9080db0 100644
--- a/fs/nfs/nfs42xattr.c
+++ b/fs/nfs/nfs42xattr.c
@@ -81,7 +81,7 @@ struct nfs4_xattr_entry {
 	struct hlist_node hnode;
 	struct list_head lru;
 	struct list_head dispose;
-	char *xattr_name;
+	const char *xattr_name;
 	void *xattr_value;
 	size_t xattr_size;
 	struct nfs4_xattr_bucket *bucket;
@@ -98,6 +98,7 @@ static struct list_lru nfs4_xattr_entry_lru;
 static struct list_lru nfs4_xattr_large_entry_lru;
 
 static struct kmem_cache *nfs4_xattr_cache_cachep;
+static struct kmem_cache *nfs4_xattr_entry_cachep;
 
 /*
  * Hashing helper functions.
@@ -177,49 +178,27 @@ nfs4_xattr_alloc_entry(const char *name, const void *value,
 {
 	struct nfs4_xattr_entry *entry;
 	void *valp;
-	char *namep;
-	size_t alloclen, slen;
-	char *buf;
-	uint32_t flags;
+	const char *namep;
+	uint32_t flags = len > PAGE_SIZE ? NFS4_XATTR_ENTRY_EXTVAL : 0;
+	gfp_t gfp = GFP_KERNEL_ACCOUNT | GFP_NOFS;
+	struct list_lru *lru;
 
 	BUILD_BUG_ON(sizeof(struct nfs4_xattr_entry) +
 	    XATTR_NAME_MAX + 1 > PAGE_SIZE);
 
-	alloclen = sizeof(struct nfs4_xattr_entry);
-	if (name != NULL) {
-		slen = strlen(name) + 1;
-		alloclen += slen;
-	} else
-		slen = 0;
-
-	if (alloclen + len <= PAGE_SIZE) {
-		alloclen += len;
-		flags = 0;
-	} else {
-		flags = NFS4_XATTR_ENTRY_EXTVAL;
-	}
-
-	buf = kmalloc(alloclen, GFP_KERNEL_ACCOUNT | GFP_NOFS);
-	if (buf == NULL)
+	lru = flags & NFS4_XATTR_ENTRY_EXTVAL ? &nfs4_xattr_large_entry_lru :
+	      &nfs4_xattr_entry_lru;
+	entry = kmem_cache_alloc_lru(nfs4_xattr_entry_cachep, lru, gfp);
+	if (!entry)
 		return NULL;
-	entry = (struct nfs4_xattr_entry *)buf;
-
-	if (name != NULL) {
-		namep = buf + sizeof(struct nfs4_xattr_entry);
-		memcpy(namep, name, slen);
-	} else {
-		namep = NULL;
-	}
-
-
-	if (flags & NFS4_XATTR_ENTRY_EXTVAL) {
-		valp = kvmalloc(len, GFP_KERNEL_ACCOUNT | GFP_NOFS);
-		if (valp == NULL) {
-			kfree(buf);
-			return NULL;
-		}
-	} else if (len != 0) {
-		valp = buf + sizeof(struct nfs4_xattr_entry) + slen;
+	namep = kstrdup_const(name, gfp);
+	if (!namep && name)
+		goto free_buf;
+
+	if (len != 0) {
+		valp = kvmalloc(len, gfp);
+		if (!valp)
+			goto free_name;
 	} else
 		valp = NULL;
 
@@ -232,23 +211,23 @@ nfs4_xattr_alloc_entry(const char *name, const void *value,
 
 	entry->flags = flags;
 	entry->xattr_value = valp;
-	kref_init(&entry->ref);
 	entry->xattr_name = namep;
 	entry->xattr_size = len;
-	entry->bucket = NULL;
-	INIT_LIST_HEAD(&entry->lru);
-	INIT_LIST_HEAD(&entry->dispose);
-	INIT_HLIST_NODE(&entry->hnode);
 
 	return entry;
+free_name:
+	kfree_const(namep);
+free_buf:
+	kmem_cache_free(nfs4_xattr_entry_cachep, entry);
+	return NULL;
 }
 
 static void
 nfs4_xattr_free_entry(struct nfs4_xattr_entry *entry)
 {
-	if (entry->flags & NFS4_XATTR_ENTRY_EXTVAL)
-		kvfree(entry->xattr_value);
-	kfree(entry);
+	kvfree(entry->xattr_value);
+	kfree_const(entry->xattr_name);
+	kmem_cache_free(nfs4_xattr_entry_cachep, entry);
 }
 
 static void
@@ -289,7 +268,7 @@ nfs4_xattr_alloc_cache(void)
 {
 	struct nfs4_xattr_cache *cache;
 
-	cache = kmem_cache_alloc(nfs4_xattr_cache_cachep,
+	cache = kmem_cache_alloc_lru(nfs4_xattr_cache_cachep, &nfs4_xattr_cache_lru,
 	    GFP_KERNEL_ACCOUNT | GFP_NOFS);
 	if (cache == NULL)
 		return NULL;
@@ -992,6 +971,17 @@ static void nfs4_xattr_cache_init_once(void *p)
 	INIT_LIST_HEAD(&cache->dispose);
 }
 
+static void nfs4_xattr_entry_init_once(void *p)
+{
+	struct nfs4_xattr_entry *entry = p;
+
+	kref_init(&entry->ref);
+	entry->bucket = NULL;
+	INIT_LIST_HEAD(&entry->lru);
+	INIT_LIST_HEAD(&entry->dispose);
+	INIT_HLIST_NODE(&entry->hnode);
+}
+
 int __init nfs4_xattr_cache_init(void)
 {
 	int ret = 0;
@@ -1003,6 +993,13 @@ int __init nfs4_xattr_cache_init(void)
 	if (nfs4_xattr_cache_cachep == NULL)
 		return -ENOMEM;
 
+	nfs4_xattr_entry_cachep = kmem_cache_create("nfs4_xattr_entry",
+			sizeof(struct nfs4_xattr_entry), 0,
+			(SLAB_RECLAIM_ACCOUNT | SLAB_MEM_SPREAD | SLAB_ACCOUNT),
+			nfs4_xattr_entry_init_once);
+	if (!nfs4_xattr_entry_cachep)
+		goto out5;
+
 	ret = list_lru_init_memcg(&nfs4_xattr_large_entry_lru,
 	    &nfs4_xattr_large_entry_shrinker);
 	if (ret)
@@ -1040,6 +1037,8 @@ int __init nfs4_xattr_cache_init(void)
 out3:
 	list_lru_destroy(&nfs4_xattr_large_entry_lru);
 out4:
+	kmem_cache_destroy(nfs4_xattr_entry_cachep);
+out5:
 	kmem_cache_destroy(nfs4_xattr_cache_cachep);
 
 	return ret;
-- 
2.11.0


^ permalink raw reply	[flat|nested] 20+ messages in thread

* [PATCH 15/17] mm: list_lru: allocate list_lru_one only when needed
  2021-05-11 10:46 [PATCH 00/17] Optimize list lru memory consumption Muchun Song
                   ` (13 preceding siblings ...)
  2021-05-11 10:46 ` [PATCH 14/17] nfs42: use a specific kmem_cache to allocate nfs4_xattr_entry Muchun Song
@ 2021-05-11 10:46 ` Muchun Song
  2021-05-11 10:46 ` [PATCH 16/17] mm: list_lru: rename memcg_drain_all_list_lrus to memcg_reparent_list_lrus Muchun Song
  2021-05-11 10:46 ` [PATCH 17/17] mm: list_lru: replace linear array with xarray Muchun Song
  16 siblings, 0 replies; 20+ messages in thread
From: Muchun Song @ 2021-05-11 10:46 UTC (permalink / raw)
  To: willy, akpm, hannes, mhocko, vdavydov.dev, shakeelb, guro,
	shy828301, alexs, richard.weiyang, david, trond.myklebust,
	anna.schumaker
  Cc: linux-fsdevel, linux-kernel, linux-mm, linux-nfs, zhengqi.arch,
	duanxiongchun, fam.zheng, Muchun Song

In our server, we found a suspected memory leak problem. The kmalloc-32
consumes more than 6GB of memory. Other kmem_caches consume less than
2GB memory.

After our in-depth analysis, the memory consumption of kmalloc-32 slab
cache is the cause of list_lru_one allocation.

  crash> p memcg_nr_cache_ids
  memcg_nr_cache_ids = $2 = 24574

memcg_nr_cache_ids is very large and memory consumption of each list_lru
can be calculated with the following formula.

  num_numa_node * memcg_nr_cache_ids * 32 (kmalloc-32)

There are 4 numa nodes in our system, so each list_lru consumes ~3MB.

  crash> list super_blocks | wc -l
  952

Every mount will register 2 list lrus, one is for inode, another is for
dentry. There are 952 super_blocks. So the total memory is 952 * 2 * 3
MB (~5.6GB). But the number of memory cgroup is less than 500. So I
guess more than 12286 containers have been deployed on this machine (I
do not know why there are so many containers, it may be a user's bug or
the user really want to do that). And memcg_nr_cache_ids has not been
reduced to a suitable value. This can waste a lot of memory.

Now the infrastructure for dynamic memory allocation is ready, so remove
statically allocated memory code to save memory.

Signed-off-by: Muchun Song <songmuchun@bytedance.com>
---
 include/linux/list_lru.h |   6 ++-
 mm/list_lru.c            | 122 +++++++++++++++++++++++++----------------------
 mm/memcontrol.c          |   6 ++-
 3 files changed, 74 insertions(+), 60 deletions(-)

diff --git a/include/linux/list_lru.h b/include/linux/list_lru.h
index 2b2fdb4de96a..7d4346b93b24 100644
--- a/include/linux/list_lru.h
+++ b/include/linux/list_lru.h
@@ -32,6 +32,7 @@ struct list_lru_one {
 };
 
 struct list_lru_per_memcg {
+	struct rcu_head		rcu;
 	/* array of per cgroup per node lists, indexed by node id */
 	struct list_lru_one	nodes[0];
 };
@@ -39,7 +40,7 @@ struct list_lru_per_memcg {
 struct list_lru_memcg {
 	struct rcu_head			rcu;
 	/* array of per cgroup lists, indexed by memcg_cache_id */
-	struct list_lru_per_memcg	*lrus[0];
+	struct list_lru_per_memcg __rcu	*lrus[0];
 };
 
 struct list_lru_node {
@@ -75,7 +76,8 @@ int __list_lru_init(struct list_lru *lru, bool memcg_aware,
 	__list_lru_init((lru), true, NULL, shrinker)
 
 int memcg_update_all_list_lrus(int num_memcgs);
-void memcg_drain_all_list_lrus(int src_idx, struct mem_cgroup *dst_memcg);
+void memcg_drain_all_list_lrus(struct mem_cgroup *src_memcg,
+			       struct mem_cgroup *dst_memcg);
 
 /**
  * list_lru_add: add an element to the lru list's tail
diff --git a/mm/list_lru.c b/mm/list_lru.c
index 182cb2a2e64f..b5ed6b797a48 100644
--- a/mm/list_lru.c
+++ b/mm/list_lru.c
@@ -60,8 +60,12 @@ list_lru_from_memcg_idx(struct list_lru *lru, int nid, int idx)
 	 */
 	memcg_lrus = rcu_dereference_check(lru->memcg_lrus,
 					   lockdep_is_held(&nlru->lock));
-	if (memcg_lrus && idx >= 0)
-		return &memcg_lrus->lrus[idx]->nodes[nid];
+	if (memcg_lrus && idx >= 0) {
+		struct list_lru_per_memcg *mlru;
+
+		mlru = rcu_dereference_check(memcg_lrus->lrus[idx], true);
+		return mlru ? &mlru->nodes[nid] : NULL;
+	}
 	return &nlru->lru;
 }
 
@@ -184,11 +188,12 @@ unsigned long list_lru_count_one(struct list_lru *lru,
 				 int nid, struct mem_cgroup *memcg)
 {
 	struct list_lru_one *l;
-	long count;
+	long count = 0;
 
 	rcu_read_lock();
 	l = list_lru_from_memcg_idx(lru, nid, memcg_cache_id(memcg));
-	count = READ_ONCE(l->nr_items);
+	if (l)
+		count = READ_ONCE(l->nr_items);
 	rcu_read_unlock();
 
 	if (unlikely(count < 0))
@@ -217,8 +222,11 @@ __list_lru_walk_one(struct list_lru *lru, int nid, int memcg_idx,
 	struct list_head *item, *n;
 	unsigned long isolated = 0;
 
-	l = list_lru_from_memcg_idx(lru, nid, memcg_idx);
 restart:
+	l = list_lru_from_memcg_idx(lru, nid, memcg_idx);
+	if (!l)
+		goto out;
+
 	list_for_each_safe(item, n, &l->list) {
 		enum lru_status ret;
 
@@ -262,6 +270,7 @@ __list_lru_walk_one(struct list_lru *lru, int nid, int memcg_idx,
 			BUG();
 		}
 	}
+out:
 	return isolated;
 }
 
@@ -354,22 +363,6 @@ static struct list_lru_per_memcg *list_lru_per_memcg_alloc(gfp_t gfp)
 	return lru;
 }
 
-static int memcg_init_list_lru_range(struct list_lru_memcg *memcg_lrus,
-				     int begin, int end)
-{
-	int i;
-
-	for (i = begin; i < end; i++) {
-		memcg_lrus->lrus[i] = list_lru_per_memcg_alloc(GFP_KERNEL);
-		if (!memcg_lrus->lrus[i])
-			goto fail;
-	}
-	return 0;
-fail:
-	memcg_destroy_list_lru_range(memcg_lrus, begin, i);
-	return -ENOMEM;
-}
-
 static int memcg_init_list_lru(struct list_lru *lru, bool memcg_aware)
 {
 	struct list_lru_memcg *memcg_lrus;
@@ -382,15 +375,11 @@ static int memcg_init_list_lru(struct list_lru *lru, bool memcg_aware)
 
 	spin_lock_init(&lru->lock);
 
-	memcg_lrus = kvmalloc(sizeof(*memcg_lrus) +
+	memcg_lrus = kvzalloc(sizeof(*memcg_lrus) +
 			      size * sizeof(memcg_lrus->lrus[0]), GFP_KERNEL);
 	if (!memcg_lrus)
 		return -ENOMEM;
 
-	if (memcg_init_list_lru_range(memcg_lrus, 0, size)) {
-		kvfree(memcg_lrus);
-		return -ENOMEM;
-	}
 	RCU_INIT_POINTER(lru->memcg_lrus, memcg_lrus);
 
 	return 0;
@@ -424,13 +413,9 @@ static int memcg_update_list_lru(struct list_lru *lru, int old_size, int new_siz
 	if (!new)
 		return -ENOMEM;
 
-	if (memcg_init_list_lru_range(new, old_size, new_size)) {
-		kvfree(new);
-		return -ENOMEM;
-	}
-
 	spin_lock_irq(&lru->lock);
 	memcpy(&new->lrus, &old->lrus, old_size * sizeof(new->lrus[0]));
+	memset(&new->lrus[old_size], 0, (new_size - old_size) * sizeof(new->lrus[0]));
 	rcu_assign_pointer(lru->memcg_lrus, new);
 	spin_unlock_irq(&lru->lock);
 
@@ -439,20 +424,6 @@ static int memcg_update_list_lru(struct list_lru *lru, int old_size, int new_siz
 	return 0;
 }
 
-static void memcg_cancel_update_list_lru(struct list_lru *lru,
-					 int old_size, int new_size)
-{
-	struct list_lru_memcg *memcg_lrus;
-
-	memcg_lrus = rcu_dereference_protected(lru->memcg_lrus,
-					       lockdep_is_held(&list_lrus_mutex));
-	/*
-	 * Do not bother shrinking the array back to the old size, because we
-	 * cannot handle allocation failures here.
-	 */
-	memcg_destroy_list_lru_range(memcg_lrus, old_size, new_size);
-}
-
 int memcg_update_all_list_lrus(int new_size)
 {
 	int ret = 0;
@@ -463,15 +434,10 @@ int memcg_update_all_list_lrus(int new_size)
 	list_for_each_entry(lru, &list_lrus, list) {
 		ret = memcg_update_list_lru(lru, old_size, new_size);
 		if (ret)
-			goto fail;
+			break;
 	}
-out:
 	mutex_unlock(&list_lrus_mutex);
 	return ret;
-fail:
-	list_for_each_entry_continue_reverse(lru, &list_lrus, list)
-		memcg_cancel_update_list_lru(lru, old_size, new_size);
-	goto out;
 }
 
 static void memcg_drain_list_lru_node(struct list_lru *lru, int nid,
@@ -488,6 +454,8 @@ static void memcg_drain_list_lru_node(struct list_lru *lru, int nid,
 	spin_lock_irq(&nlru->lock);
 
 	src = list_lru_from_memcg_idx(lru, nid, src_idx);
+	if (!src)
+		goto out;
 	dst = list_lru_from_memcg_idx(lru, nid, dst_idx);
 
 	list_splice_init(&src->list, &dst->list);
@@ -497,10 +465,32 @@ static void memcg_drain_list_lru_node(struct list_lru *lru, int nid,
 		set_shrinker_bit(dst_memcg, nid, lru_shrinker_id(lru));
 		src->nr_items = 0;
 	}
-
+out:
 	spin_unlock_irq(&nlru->lock);
 }
 
+static void list_lru_per_memcg_free(struct list_lru *lru, int src_idx)
+{
+	struct list_lru_memcg *memcg_lrus;
+	struct list_lru_per_memcg *mlru;
+
+	spin_lock_irq(&lru->lock);
+	memcg_lrus = rcu_dereference_protected(lru->memcg_lrus, true);
+	mlru = rcu_dereference_protected(memcg_lrus->lrus[src_idx], true);
+	if (mlru)
+		rcu_assign_pointer(memcg_lrus->lrus[src_idx], NULL);
+	spin_unlock_irq(&lru->lock);
+
+	/*
+	 * The __list_lru_walk_one() can walk the list of this node.
+	 * We need kvfree_rcu() here. And the walking of the list
+	 * is under lru->node[nid]->lock, which can serve as a RCU
+	 * read-side critical section.
+	 */
+	if (mlru)
+		kvfree_rcu(mlru, rcu);
+}
+
 static void memcg_drain_list_lru(struct list_lru *lru,
 				 int src_idx, struct mem_cgroup *dst_memcg)
 {
@@ -508,11 +498,28 @@ static void memcg_drain_list_lru(struct list_lru *lru,
 
 	for_each_node(i)
 		memcg_drain_list_lru_node(lru, i, src_idx, dst_memcg);
+
+	list_lru_per_memcg_free(lru, src_idx);
 }
 
-void memcg_drain_all_list_lrus(int src_idx, struct mem_cgroup *dst_memcg)
+void memcg_drain_all_list_lrus(struct mem_cgroup *src_memcg,
+			       struct mem_cgroup *dst_memcg)
 {
 	struct list_lru *lru;
+	int src_idx = src_memcg->kmemcg_id;
+
+	/*
+	 * Change kmemcg_id of this cgroup to the parent's id, and then move
+	 * all entries from this cgroup's list_lrus to ones of the parent.
+	 *
+	 * After we have finished, all list_lrus corresponding to this cgroup
+	 * are guaranteed to remain empty. So we can safely free this cgroup's
+	 * list lrus which is implemented in list_lru_per_memcg_free().
+	 * Changing ->kmemcg_id to the parent can prevent list_lru_memcg_alloc()
+	 * from allocating list lrus for this cgroup after calling
+	 * list_lru_per_memcg_free().
+	 */
+	src_memcg->kmemcg_id = dst_memcg->kmemcg_id;
 
 	mutex_lock(&list_lrus_mutex);
 	list_for_each_entry(lru, &list_lrus, list)
@@ -531,7 +538,7 @@ static bool list_lru_per_memcg_allocated(struct list_lru *lru,
 
 	rcu_read_lock();
 	memcg_lrus = rcu_dereference(lru->memcg_lrus);
-	if (memcg_lrus->lrus[idx]) {
+	if (rcu_access_pointer(memcg_lrus->lrus[idx])) {
 		rcu_read_unlock();
 		return true;
 	}
@@ -590,11 +597,12 @@ int list_lru_memcg_alloc(struct list_lru *lru, struct mem_cgroup *memcg, gfp_t g
 	memcg_lrus = rcu_dereference_protected(lru->memcg_lrus, true);
 	while (i--) {
 		int idx = memcg_cache_id(table[i].memcg);
+		struct list_lru_per_memcg *mlru = table[i].mlru;
 
-		if (memcg_lrus->lrus[idx])
-			kfree(table[i].mlru);
+		if (idx < 0 || rcu_dereference_protected(memcg_lrus->lrus[idx], true))
+			kfree(mlru);
 		else
-			memcg_lrus->lrus[idx] = table[i].mlru;
+			rcu_assign_pointer(memcg_lrus->lrus[idx], mlru);
 	}
 	spin_unlock_irqrestore(&lru->lock, flags);
 
diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index 6aace39fd1a4..879d2ff8d81f 100644
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -3484,11 +3484,15 @@ static void memcg_offline_kmem(struct mem_cgroup *memcg)
 
 	memcg_reparent_objcgs(memcg, parent);
 
+	/*
+	 * memcg_drain_all_list_lrus() can change memcg->kmemcg_id.
+	 * Cache it to @kmemcg_id.
+	 */
 	kmemcg_id = memcg->kmemcg_id;
 	BUG_ON(kmemcg_id < 0);
 
 	/* memcg_reparent_objcgs() must be called before this. */
-	memcg_drain_all_list_lrus(kmemcg_id, parent);
+	memcg_drain_all_list_lrus(memcg, parent);
 
 	memcg_free_cache_id(kmemcg_id);
 }
-- 
2.11.0


^ permalink raw reply	[flat|nested] 20+ messages in thread

* [PATCH 16/17] mm: list_lru: rename memcg_drain_all_list_lrus to memcg_reparent_list_lrus
  2021-05-11 10:46 [PATCH 00/17] Optimize list lru memory consumption Muchun Song
                   ` (14 preceding siblings ...)
  2021-05-11 10:46 ` [PATCH 15/17] mm: list_lru: allocate list_lru_one only when needed Muchun Song
@ 2021-05-11 10:46 ` Muchun Song
  2021-05-11 10:46 ` [PATCH 17/17] mm: list_lru: replace linear array with xarray Muchun Song
  16 siblings, 0 replies; 20+ messages in thread
From: Muchun Song @ 2021-05-11 10:46 UTC (permalink / raw)
  To: willy, akpm, hannes, mhocko, vdavydov.dev, shakeelb, guro,
	shy828301, alexs, richard.weiyang, david, trond.myklebust,
	anna.schumaker
  Cc: linux-fsdevel, linux-kernel, linux-mm, linux-nfs, zhengqi.arch,
	duanxiongchun, fam.zheng, Muchun Song

The purpose of the memcg_drain_all_list_lrus() is list_lrus reparenting.
It is very similar to memcg_reparent_objcgs(). Rename it to
memcg_reparent_list_lrus() so that the name can more consistent with
memcg_reparent_objcgs().

Signed-off-by: Muchun Song <songmuchun@bytedance.com>
---
 include/linux/list_lru.h |  3 +--
 mm/list_lru.c            | 19 +++++++++----------
 mm/memcontrol.c          |  4 ++--
 3 files changed, 12 insertions(+), 14 deletions(-)

diff --git a/include/linux/list_lru.h b/include/linux/list_lru.h
index 7d4346b93b24..9222d0295d30 100644
--- a/include/linux/list_lru.h
+++ b/include/linux/list_lru.h
@@ -76,8 +76,7 @@ int __list_lru_init(struct list_lru *lru, bool memcg_aware,
 	__list_lru_init((lru), true, NULL, shrinker)
 
 int memcg_update_all_list_lrus(int num_memcgs);
-void memcg_drain_all_list_lrus(struct mem_cgroup *src_memcg,
-			       struct mem_cgroup *dst_memcg);
+void memcg_reparent_list_lrus(struct mem_cgroup *memcg, struct mem_cgroup *parent);
 
 /**
  * list_lru_add: add an element to the lru list's tail
diff --git a/mm/list_lru.c b/mm/list_lru.c
index b5ed6b797a48..6d7ae24a4a70 100644
--- a/mm/list_lru.c
+++ b/mm/list_lru.c
@@ -440,8 +440,8 @@ int memcg_update_all_list_lrus(int new_size)
 	return ret;
 }
 
-static void memcg_drain_list_lru_node(struct list_lru *lru, int nid,
-				      int src_idx, struct mem_cgroup *dst_memcg)
+static void memcg_reparent_list_lru_node(struct list_lru *lru, int nid,
+					 int src_idx, struct mem_cgroup *dst_memcg)
 {
 	struct list_lru_node *nlru = &lru->node[nid];
 	int dst_idx = dst_memcg->kmemcg_id;
@@ -491,22 +491,21 @@ static void list_lru_per_memcg_free(struct list_lru *lru, int src_idx)
 		kvfree_rcu(mlru, rcu);
 }
 
-static void memcg_drain_list_lru(struct list_lru *lru,
-				 int src_idx, struct mem_cgroup *dst_memcg)
+static void memcg_reparent_list_lru(struct list_lru *lru,
+				    int src_idx, struct mem_cgroup *dst_memcg)
 {
 	int i;
 
 	for_each_node(i)
-		memcg_drain_list_lru_node(lru, i, src_idx, dst_memcg);
+		memcg_reparent_list_lru_node(lru, i, src_idx, dst_memcg);
 
 	list_lru_per_memcg_free(lru, src_idx);
 }
 
-void memcg_drain_all_list_lrus(struct mem_cgroup *src_memcg,
-			       struct mem_cgroup *dst_memcg)
+void memcg_reparent_list_lrus(struct mem_cgroup *memcg, struct mem_cgroup *parent)
 {
 	struct list_lru *lru;
-	int src_idx = src_memcg->kmemcg_id;
+	int src_idx = memcg->kmemcg_id;
 
 	/*
 	 * Change kmemcg_id of this cgroup to the parent's id, and then move
@@ -519,11 +518,11 @@ void memcg_drain_all_list_lrus(struct mem_cgroup *src_memcg,
 	 * from allocating list lrus for this cgroup after calling
 	 * list_lru_per_memcg_free().
 	 */
-	src_memcg->kmemcg_id = dst_memcg->kmemcg_id;
+	memcg->kmemcg_id = parent->kmemcg_id;
 
 	mutex_lock(&list_lrus_mutex);
 	list_for_each_entry(lru, &list_lrus, list)
-		memcg_drain_list_lru(lru, src_idx, dst_memcg);
+		memcg_reparent_list_lru(lru, src_idx, parent);
 	mutex_unlock(&list_lrus_mutex);
 }
 
diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index 879d2ff8d81f..02a65ff3b77a 100644
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -3485,14 +3485,14 @@ static void memcg_offline_kmem(struct mem_cgroup *memcg)
 	memcg_reparent_objcgs(memcg, parent);
 
 	/*
-	 * memcg_drain_all_list_lrus() can change memcg->kmemcg_id.
+	 * memcg_reparent_list_lrus() can change memcg->kmemcg_id.
 	 * Cache it to @kmemcg_id.
 	 */
 	kmemcg_id = memcg->kmemcg_id;
 	BUG_ON(kmemcg_id < 0);
 
 	/* memcg_reparent_objcgs() must be called before this. */
-	memcg_drain_all_list_lrus(memcg, parent);
+	memcg_reparent_list_lrus(memcg, parent);
 
 	memcg_free_cache_id(kmemcg_id);
 }
-- 
2.11.0


^ permalink raw reply	[flat|nested] 20+ messages in thread

* [PATCH 17/17] mm: list_lru: replace linear array with xarray
  2021-05-11 10:46 [PATCH 00/17] Optimize list lru memory consumption Muchun Song
                   ` (15 preceding siblings ...)
  2021-05-11 10:46 ` [PATCH 16/17] mm: list_lru: rename memcg_drain_all_list_lrus to memcg_reparent_list_lrus Muchun Song
@ 2021-05-11 10:46 ` Muchun Song
  16 siblings, 0 replies; 20+ messages in thread
From: Muchun Song @ 2021-05-11 10:46 UTC (permalink / raw)
  To: willy, akpm, hannes, mhocko, vdavydov.dev, shakeelb, guro,
	shy828301, alexs, richard.weiyang, david, trond.myklebust,
	anna.schumaker
  Cc: linux-fsdevel, linux-kernel, linux-mm, linux-nfs, zhengqi.arch,
	duanxiongchun, fam.zheng, Muchun Song

If we run 10k containers in the system, the size of the
list_lru_memcg->lrus can be ~96KB per list_lru. When we decrease the
number containers, the size of the array will not be shrinked. It is
not scalable. The xarray is a good choice for this case. We can save
a lot of memory when there are tens of thousands continers in the
system. If we use xarray, we also can remove the logic code of
resizing array, which can simplify the code.

Signed-off-by: Muchun Song <songmuchun@bytedance.com>
---
 include/linux/list_lru.h   |   6 +-
 include/linux/memcontrol.h |  10 ---
 mm/list_lru.c              | 159 ++++++++++++---------------------------------
 mm/memcontrol.c            |  71 ++------------------
 4 files changed, 49 insertions(+), 197 deletions(-)

diff --git a/include/linux/list_lru.h b/include/linux/list_lru.h
index 9222d0295d30..b57556698de0 100644
--- a/include/linux/list_lru.h
+++ b/include/linux/list_lru.h
@@ -11,6 +11,7 @@
 #include <linux/list.h>
 #include <linux/nodemask.h>
 #include <linux/shrinker.h>
+#include <linux/xarray.h>
 
 struct mem_cgroup;
 
@@ -56,10 +57,8 @@ struct list_lru {
 #ifdef CONFIG_MEMCG_KMEM
 	struct list_head	list;
 	int			shrinker_id;
-	/* protects ->memcg_lrus->lrus[i] */
-	spinlock_t		lock;
 	/* for cgroup aware lrus points to per cgroup lists, otherwise NULL */
-	struct list_lru_memcg	__rcu *memcg_lrus;
+	struct xarray		*xa;
 #endif
 };
 
@@ -75,7 +74,6 @@ int __list_lru_init(struct list_lru *lru, bool memcg_aware,
 #define list_lru_init_memcg(lru, shrinker)		\
 	__list_lru_init((lru), true, NULL, shrinker)
 
-int memcg_update_all_list_lrus(int num_memcgs);
 void memcg_reparent_list_lrus(struct mem_cgroup *memcg, struct mem_cgroup *parent);
 
 /**
diff --git a/include/linux/memcontrol.h b/include/linux/memcontrol.h
index 96a85cff248a..a0c77e8ec61a 100644
--- a/include/linux/memcontrol.h
+++ b/include/linux/memcontrol.h
@@ -1649,8 +1649,6 @@ void obj_cgroup_uncharge(struct obj_cgroup *objcg, size_t size);
 extern struct static_key_false memcg_kmem_enabled_key;
 
 extern int memcg_nr_cache_ids;
-void memcg_get_cache_ids(void);
-void memcg_put_cache_ids(void);
 
 /*
  * Helper macro to loop through all memcg-specific caches. Callers must still
@@ -1725,14 +1723,6 @@ static inline int memcg_cache_id(struct mem_cgroup *memcg)
 	return -1;
 }
 
-static inline void memcg_get_cache_ids(void)
-{
-}
-
-static inline void memcg_put_cache_ids(void)
-{
-}
-
 static inline struct mem_cgroup *mem_cgroup_from_obj(void *p)
 {
        return NULL;
diff --git a/mm/list_lru.c b/mm/list_lru.c
index 6d7ae24a4a70..9878b08d44e4 100644
--- a/mm/list_lru.c
+++ b/mm/list_lru.c
@@ -20,7 +20,7 @@ static DEFINE_MUTEX(list_lrus_mutex);
 
 static inline bool list_lru_memcg_aware(struct list_lru *lru)
 {
-	return !!lru->memcg_lrus;
+	return !!lru->xa;
 }
 
 static void list_lru_register(struct list_lru *lru)
@@ -51,22 +51,12 @@ static int lru_shrinker_id(struct list_lru *lru)
 static inline struct list_lru_one *
 list_lru_from_memcg_idx(struct list_lru *lru, int nid, int idx)
 {
-	struct list_lru_memcg *memcg_lrus;
-	struct list_lru_node *nlru = &lru->node[nid];
+	if (list_lru_memcg_aware(lru) && idx >= 0) {
+		struct list_lru_per_memcg *mlru = xa_load(lru->xa, idx);
 
-	/*
-	 * Either lock or RCU protects the array of per cgroup lists
-	 * from relocation (see memcg_update_list_lru).
-	 */
-	memcg_lrus = rcu_dereference_check(lru->memcg_lrus,
-					   lockdep_is_held(&nlru->lock));
-	if (memcg_lrus && idx >= 0) {
-		struct list_lru_per_memcg *mlru;
-
-		mlru = rcu_dereference_check(memcg_lrus->lrus[idx], true);
 		return mlru ? &mlru->nodes[nid] : NULL;
 	}
-	return &nlru->lru;
+	return &lru->node[nid].lru;
 }
 
 static inline struct list_lru_one *
@@ -310,16 +300,18 @@ unsigned long list_lru_walk_node(struct list_lru *lru, int nid,
 				 unsigned long *nr_to_walk)
 {
 	long isolated = 0;
-	int memcg_idx;
 
 	isolated += list_lru_walk_one(lru, nid, NULL, isolate, cb_arg,
 				      nr_to_walk);
 	if (*nr_to_walk > 0 && list_lru_memcg_aware(lru)) {
-		for_each_memcg_cache_index(memcg_idx) {
+		struct list_lru_per_memcg *mlru;
+		unsigned long index;
+
+		xa_for_each(lru->xa, index, mlru) {
 			struct list_lru_node *nlru = &lru->node[nid];
 
 			spin_lock(&nlru->lock);
-			isolated += __list_lru_walk_one(lru, nid, memcg_idx,
+			isolated += __list_lru_walk_one(lru, nid, index,
 							isolate, cb_arg,
 							nr_to_walk);
 			spin_unlock(&nlru->lock);
@@ -339,15 +331,6 @@ static void init_one_lru(struct list_lru_one *l)
 }
 
 #ifdef CONFIG_MEMCG_KMEM
-static void memcg_destroy_list_lru_range(struct list_lru_memcg *memcg_lrus,
-					 int begin, int end)
-{
-	int i;
-
-	for (i = begin; i < end; i++)
-		kfree(memcg_lrus->lrus[i]);
-}
-
 static struct list_lru_per_memcg *list_lru_per_memcg_alloc(gfp_t gfp)
 {
 	int nid;
@@ -365,79 +348,35 @@ static struct list_lru_per_memcg *list_lru_per_memcg_alloc(gfp_t gfp)
 
 static int memcg_init_list_lru(struct list_lru *lru, bool memcg_aware)
 {
-	struct list_lru_memcg *memcg_lrus;
-	int size = memcg_nr_cache_ids;
-
 	if (!memcg_aware) {
-		lru->memcg_lrus = NULL;
+		lru->xa = NULL;
 		return 0;
 	}
 
-	spin_lock_init(&lru->lock);
-
-	memcg_lrus = kvzalloc(sizeof(*memcg_lrus) +
-			      size * sizeof(memcg_lrus->lrus[0]), GFP_KERNEL);
-	if (!memcg_lrus)
+	lru->xa = kmalloc(sizeof(*lru->xa), GFP_KERNEL);
+	if (!lru->xa)
 		return -ENOMEM;
-
-	RCU_INIT_POINTER(lru->memcg_lrus, memcg_lrus);
+	xa_init_flags(lru->xa, XA_FLAGS_LOCK_IRQ);
 
 	return 0;
 }
 
 static void memcg_destroy_list_lru(struct list_lru *lru)
 {
-	struct list_lru_memcg *memcg_lrus;
+	XA_STATE(xas, lru->xa, 0);
+	struct list_lru_per_memcg *mlru;
 
 	if (!list_lru_memcg_aware(lru))
 		return;
 
-	/*
-	 * This is called when shrinker has already been unregistered,
-	 * and nobody can use it. So, there is no need to use kvfree_rcu().
-	 */
-	memcg_lrus = rcu_dereference_protected(lru->memcg_lrus, true);
-	memcg_destroy_list_lru_range(memcg_lrus, 0, memcg_nr_cache_ids);
-	kvfree(memcg_lrus);
-}
-
-static int memcg_update_list_lru(struct list_lru *lru, int old_size, int new_size)
-{
-	struct list_lru_memcg *old, *new;
-
-	BUG_ON(old_size > new_size);
-
-	old = rcu_dereference_protected(lru->memcg_lrus,
-					lockdep_is_held(&list_lrus_mutex));
-	new = kvmalloc(sizeof(*new) + new_size * sizeof(new->lrus[0]), GFP_KERNEL);
-	if (!new)
-		return -ENOMEM;
-
-	spin_lock_irq(&lru->lock);
-	memcpy(&new->lrus, &old->lrus, old_size * sizeof(new->lrus[0]));
-	memset(&new->lrus[old_size], 0, (new_size - old_size) * sizeof(new->lrus[0]));
-	rcu_assign_pointer(lru->memcg_lrus, new);
-	spin_unlock_irq(&lru->lock);
-
-	kvfree_rcu(old, rcu);
-
-	return 0;
-}
-
-int memcg_update_all_list_lrus(int new_size)
-{
-	int ret = 0;
-	struct list_lru *lru;
-	int old_size = memcg_nr_cache_ids;
-
-	mutex_lock(&list_lrus_mutex);
-	list_for_each_entry(lru, &list_lrus, list) {
-		ret = memcg_update_list_lru(lru, old_size, new_size);
-		if (ret)
-			break;
+	xas_lock_irq(&xas);
+	xas_for_each(&xas, mlru, ULONG_MAX) {
+		kfree(mlru);
+		xas_store(&xas, NULL);
 	}
-	mutex_unlock(&list_lrus_mutex);
-	return ret;
+	xas_unlock_irq(&xas);
+
+	kfree(lru->xa);
 }
 
 static void memcg_reparent_list_lru_node(struct list_lru *lru, int nid,
@@ -471,15 +410,7 @@ static void memcg_reparent_list_lru_node(struct list_lru *lru, int nid,
 
 static void list_lru_per_memcg_free(struct list_lru *lru, int src_idx)
 {
-	struct list_lru_memcg *memcg_lrus;
-	struct list_lru_per_memcg *mlru;
-
-	spin_lock_irq(&lru->lock);
-	memcg_lrus = rcu_dereference_protected(lru->memcg_lrus, true);
-	mlru = rcu_dereference_protected(memcg_lrus->lrus[src_idx], true);
-	if (mlru)
-		rcu_assign_pointer(memcg_lrus->lrus[src_idx], NULL);
-	spin_unlock_irq(&lru->lock);
+	struct list_lru_per_memcg *mlru = xa_erase_irq(lru->xa, src_idx);
 
 	/*
 	 * The __list_lru_walk_one() can walk the list of this node.
@@ -529,28 +460,18 @@ void memcg_reparent_list_lrus(struct mem_cgroup *memcg, struct mem_cgroup *paren
 static bool list_lru_per_memcg_allocated(struct list_lru *lru,
 					 struct mem_cgroup *memcg)
 {
-	struct list_lru_memcg *memcg_lrus;
 	int idx = memcg_cache_id(memcg);
 
-	if (unlikely(idx < 0))
+	if (unlikely(idx < 0) || xa_load(lru->xa, idx))
 		return true;
-
-	rcu_read_lock();
-	memcg_lrus = rcu_dereference(lru->memcg_lrus);
-	if (rcu_access_pointer(memcg_lrus->lrus[idx])) {
-		rcu_read_unlock();
-		return true;
-	}
-	rcu_read_unlock();
-
 	return false;
 }
 
 int list_lru_memcg_alloc(struct list_lru *lru, struct mem_cgroup *memcg, gfp_t gfp)
 {
+	XA_STATE(xas, lru->xa, 0);
 	unsigned long flags;
-	struct list_lru_memcg *memcg_lrus;
-	int i;
+	int i, ret = 0;
 
 	struct list_lru_memcg {
 		struct list_lru_per_memcg *mlru;
@@ -592,22 +513,31 @@ int list_lru_memcg_alloc(struct list_lru *lru, struct mem_cgroup *memcg, gfp_t g
 		}
 	}
 
-	spin_lock_irqsave(&lru->lock, flags);
-	memcg_lrus = rcu_dereference_protected(lru->memcg_lrus, true);
+	xas_lock_irqsave(&xas, flags);
 	while (i--) {
 		int idx = memcg_cache_id(table[i].memcg);
 		struct list_lru_per_memcg *mlru = table[i].mlru;
 
-		if (idx < 0 || rcu_dereference_protected(memcg_lrus->lrus[idx], true))
+		xas_set(&xas, idx);
+retry:
+		if (unlikely(ret || idx < 0 || xas_load(&xas))) {
 			kfree(mlru);
-		else
-			rcu_assign_pointer(memcg_lrus->lrus[idx], mlru);
+		} else {
+			ret = xa_err(xas_store(&xas, mlru));
+			if (ret) {
+				xas_unlock_irqrestore(&xas, flags);
+				if (xas_nomem(&xas, gfp))
+					ret = 0;
+				xas_lock_irqsave(&xas, flags);
+				goto retry;
+			}
+		}
 	}
-	spin_unlock_irqrestore(&lru->lock, flags);
+	xas_unlock_irqrestore(&xas, flags);
 
 	kfree(table);
 
-	return 0;
+	return ret;
 }
 #else
 static int memcg_init_list_lru(struct list_lru *lru, bool memcg_aware)
@@ -632,7 +562,6 @@ int __list_lru_init(struct list_lru *lru, bool memcg_aware,
 	else
 		lru->shrinker_id = -1;
 #endif
-	memcg_get_cache_ids();
 
 	lru->node = kcalloc(nr_node_ids, sizeof(*lru->node), GFP_KERNEL);
 	if (!lru->node)
@@ -655,7 +584,6 @@ int __list_lru_init(struct list_lru *lru, bool memcg_aware,
 
 	list_lru_register(lru);
 out:
-	memcg_put_cache_ids();
 	return err;
 }
 EXPORT_SYMBOL_GPL(__list_lru_init);
@@ -666,8 +594,6 @@ void list_lru_destroy(struct list_lru *lru)
 	if (!lru->node)
 		return;
 
-	memcg_get_cache_ids();
-
 	list_lru_unregister(lru);
 
 	memcg_destroy_list_lru(lru);
@@ -677,6 +603,5 @@ void list_lru_destroy(struct list_lru *lru)
 #ifdef CONFIG_MEMCG_KMEM
 	lru->shrinker_id = -1;
 #endif
-	memcg_put_cache_ids();
 }
 EXPORT_SYMBOL_GPL(list_lru_destroy);
diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index 02a65ff3b77a..b30832266bf7 100644
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -352,28 +352,9 @@ static void memcg_reparent_objcgs(struct mem_cgroup *memcg,
  * This will be used as a shrinker list's index.
  * The main reason for not using cgroup id for this:
  *  this works better in sparse environments, where we have a lot of memcgs,
- *  but only a few kmem-limited. Or also, if we have, for instance, 200
- *  memcgs, and none but the 200th is kmem-limited, we'd have to have a
- *  200 entry array for that.
- *
- * The current size of the caches array is stored in memcg_nr_cache_ids. It
- * will double each time we have to increase it.
+ *  but only a few kmem-limited.
  */
 static DEFINE_IDA(memcg_cache_ida);
-int memcg_nr_cache_ids;
-
-/* Protects memcg_nr_cache_ids */
-static DECLARE_RWSEM(memcg_cache_ids_sem);
-
-void memcg_get_cache_ids(void)
-{
-	down_read(&memcg_cache_ids_sem);
-}
-
-void memcg_put_cache_ids(void)
-{
-	up_read(&memcg_cache_ids_sem);
-}
 
 /*
  * MIN_SIZE is different than 1, because we would like to avoid going through
@@ -2832,49 +2813,6 @@ __always_inline struct obj_cgroup *get_obj_cgroup_from_current(void)
 	return objcg;
 }
 
-static int memcg_alloc_cache_id(void)
-{
-	int id, size;
-	int err;
-
-	id = ida_simple_get(&memcg_cache_ida,
-			    0, MEMCG_CACHES_MAX_SIZE, GFP_KERNEL);
-	if (id < 0)
-		return id;
-
-	if (id < memcg_nr_cache_ids)
-		return id;
-
-	/*
-	 * There's no space for the new id in memcg_caches arrays,
-	 * so we have to grow them.
-	 */
-	down_write(&memcg_cache_ids_sem);
-
-	size = 2 * (id + 1);
-	if (size < MEMCG_CACHES_MIN_SIZE)
-		size = MEMCG_CACHES_MIN_SIZE;
-	else if (size > MEMCG_CACHES_MAX_SIZE)
-		size = MEMCG_CACHES_MAX_SIZE;
-
-	err = memcg_update_all_list_lrus(size);
-	if (!err)
-		memcg_nr_cache_ids = size;
-
-	up_write(&memcg_cache_ids_sem);
-
-	if (err) {
-		ida_simple_remove(&memcg_cache_ida, id);
-		return err;
-	}
-	return id;
-}
-
-static void memcg_free_cache_id(int id)
-{
-	ida_simple_remove(&memcg_cache_ida, id);
-}
-
 /*
  * obj_cgroup_uncharge_pages: uncharge a number of kernel pages from a objcg
  * @objcg: object cgroup to uncharge
@@ -3451,13 +3389,14 @@ static int memcg_online_kmem(struct mem_cgroup *memcg)
 
 	BUG_ON(memcg->kmemcg_id >= 0);
 
-	memcg_id = memcg_alloc_cache_id();
+	memcg_id = ida_simple_get(&memcg_cache_ida, 0, MEMCG_CACHES_MAX_SIZE,
+				  GFP_KERNEL);
 	if (memcg_id < 0)
 		return memcg_id;
 
 	objcg = obj_cgroup_alloc();
 	if (!objcg) {
-		memcg_free_cache_id(memcg_id);
+		ida_simple_remove(&memcg_cache_ida, memcg_id);
 		return -ENOMEM;
 	}
 	objcg->memcg = memcg;
@@ -3494,7 +3433,7 @@ static void memcg_offline_kmem(struct mem_cgroup *memcg)
 	/* memcg_reparent_objcgs() must be called before this. */
 	memcg_reparent_list_lrus(memcg, parent);
 
-	memcg_free_cache_id(kmemcg_id);
+	ida_simple_remove(&memcg_cache_ida, kmemcg_id);
 }
 #else
 static int memcg_online_kmem(struct mem_cgroup *memcg)
-- 
2.11.0


^ permalink raw reply	[flat|nested] 20+ messages in thread

* Re: [PATCH 10/17] fs: introduce alloc_inode_sb() to allocate filesystems specific inode
  2021-05-11 10:46 ` [PATCH 10/17] fs: introduce alloc_inode_sb() to allocate filesystems specific inode Muchun Song
@ 2021-05-11 23:40   ` Dave Chinner
  2021-05-12  3:20     ` [External] " Muchun Song
  0 siblings, 1 reply; 20+ messages in thread
From: Dave Chinner @ 2021-05-11 23:40 UTC (permalink / raw)
  To: Muchun Song
  Cc: willy, akpm, hannes, mhocko, vdavydov.dev, shakeelb, guro,
	shy828301, alexs, richard.weiyang, trond.myklebust,
	anna.schumaker, linux-fsdevel, linux-kernel, linux-mm, linux-nfs,
	zhengqi.arch, duanxiongchun, fam.zheng

On Tue, May 11, 2021 at 06:46:40PM +0800, Muchun Song wrote:
> The allocated inode cache will be added into its memcg lru list later,
> but we do not allocate list_lru in the later patch. So the caller should
> call kmem_cache_alloc_lru() to allocate inode and related list_lru.
> Introduce alloc_inode_sb() to do that and convert all inodes allocation
> to it.

FWIW, this probably needs a documentation update to mention that
inodes should always be allocated through alloc_inode_sb() rather
than kmem_cache_alloc(). It's a "** mandatory **" requirement as per
Documentation/filesytems/porting.rst.

Also,

> diff --git a/include/linux/fs.h b/include/linux/fs.h
> index c3c88fdb9b2a..d8d5d4eb68d6 100644
> --- a/include/linux/fs.h
> +++ b/include/linux/fs.h
> @@ -41,6 +41,7 @@
>  #include <linux/stddef.h>
>  #include <linux/mount.h>
>  #include <linux/cred.h>
> +#include <linux/slab.h>
>  
>  #include <asm/byteorder.h>
>  #include <uapi/linux/fs.h>
> @@ -3200,6 +3201,12 @@ extern void free_inode_nonrcu(struct inode *inode);
>  extern int should_remove_suid(struct dentry *);
>  extern int file_remove_privs(struct file *);
>  
> +static inline void *
> +alloc_inode_sb(struct super_block *sb, struct kmem_cache *cache, gfp_t gfp)
> +{
> +	return kmem_cache_alloc_lru(cache, &sb->s_inode_lru, gfp);
> +}
> +

This really needs a kerneldoc comment explaining that it must be
used for allocating inodes to set up the inode reclaim context
correctly....

/me wonders if we should add a BUG_ON() check in inode_init_always()
to capture filesystems that don't call through
kmem_cache_alloc_lru() for inodes?

Cheers,

Dave.
-- 
Dave Chinner
david@fromorbit.com

^ permalink raw reply	[flat|nested] 20+ messages in thread

* Re: [External] Re: [PATCH 10/17] fs: introduce alloc_inode_sb() to allocate filesystems specific inode
  2021-05-11 23:40   ` Dave Chinner
@ 2021-05-12  3:20     ` Muchun Song
  0 siblings, 0 replies; 20+ messages in thread
From: Muchun Song @ 2021-05-12  3:20 UTC (permalink / raw)
  To: Dave Chinner
  Cc: Matthew Wilcox, Andrew Morton, Johannes Weiner, Michal Hocko,
	Vladimir Davydov, Shakeel Butt, Roman Gushchin, Yang Shi, alexs,
	Wei Yang, trond.myklebust, anna.schumaker, linux-fsdevel, LKML,
	Linux Memory Management List, linux-nfs, zhengqi.arch,
	Xiongchun duan, fam.zheng

On Wed, May 12, 2021 at 7:40 AM Dave Chinner <david@fromorbit.com> wrote:
>
> On Tue, May 11, 2021 at 06:46:40PM +0800, Muchun Song wrote:
> > The allocated inode cache will be added into its memcg lru list later,
> > but we do not allocate list_lru in the later patch. So the caller should
> > call kmem_cache_alloc_lru() to allocate inode and related list_lru.
> > Introduce alloc_inode_sb() to do that and convert all inodes allocation
> > to it.
>
> FWIW, this probably needs a documentation update to mention that
> inodes should always be allocated through alloc_inode_sb() rather
> than kmem_cache_alloc(). It's a "** mandatory **" requirement as per
> Documentation/filesytems/porting.rst.

Make sense to me. I'll fix it in the next version.

>
> Also,
>
> > diff --git a/include/linux/fs.h b/include/linux/fs.h
> > index c3c88fdb9b2a..d8d5d4eb68d6 100644
> > --- a/include/linux/fs.h
> > +++ b/include/linux/fs.h
> > @@ -41,6 +41,7 @@
> >  #include <linux/stddef.h>
> >  #include <linux/mount.h>
> >  #include <linux/cred.h>
> > +#include <linux/slab.h>
> >
> >  #include <asm/byteorder.h>
> >  #include <uapi/linux/fs.h>
> > @@ -3200,6 +3201,12 @@ extern void free_inode_nonrcu(struct inode *inode);
> >  extern int should_remove_suid(struct dentry *);
> >  extern int file_remove_privs(struct file *);
> >
> > +static inline void *
> > +alloc_inode_sb(struct super_block *sb, struct kmem_cache *cache, gfp_t gfp)
> > +{
> > +     return kmem_cache_alloc_lru(cache, &sb->s_inode_lru, gfp);
> > +}
> > +
>
> This really needs a kerneldoc comment explaining that it must be
> used for allocating inodes to set up the inode reclaim context
> correctly....

Will do.

>
> /me wonders if we should add a BUG_ON() check in inode_init_always()
> to capture filesystems that don't call through
> kmem_cache_alloc_lru() for inodes?

Good point. IMHO, I think that the BUG_ON check may be useful.
Actually, it can catch such bugs.

Any suggestions from others?

Thanks.

>
> Cheers,
>
> Dave.
> --
> Dave Chinner
> david@fromorbit.com

^ permalink raw reply	[flat|nested] 20+ messages in thread

end of thread, other threads:[~2021-05-12  3:20 UTC | newest]

Thread overview: 20+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2021-05-11 10:46 [PATCH 00/17] Optimize list lru memory consumption Muchun Song
2021-05-11 10:46 ` [PATCH 01/17] mm: list_lru: fix list_lru_count_one() return value Muchun Song
2021-05-11 10:46 ` [PATCH 02/17] mm: memcontrol: remove kmemcg_id reparenting Muchun Song
2021-05-11 10:46 ` [PATCH 03/17] mm: memcontrol: remove the kmem states Muchun Song
2021-05-11 10:46 ` [PATCH 04/17] mm: memcontrol: move memcg_online_kmem() to mem_cgroup_css_online() Muchun Song
2021-05-11 10:46 ` [PATCH 05/17] mm: list_lru: remove holding lru node lock Muchun Song
2021-05-11 10:46 ` [PATCH 06/17] mm: list_lru: only add the memcg aware lrus to the list Muchun Song
2021-05-11 10:46 ` [PATCH 07/17] mm: list_lru: optimize the array of per memcg lists Muchun Song
2021-05-11 10:46 ` [PATCH 08/17] mm: list_lru: remove memcg_aware from struct list_lru Muchun Song
2021-05-11 10:46 ` [PATCH 09/17] mm: introduce kmem_cache_alloc_lru Muchun Song
2021-05-11 10:46 ` [PATCH 10/17] fs: introduce alloc_inode_sb() to allocate filesystems specific inode Muchun Song
2021-05-11 23:40   ` Dave Chinner
2021-05-12  3:20     ` [External] " Muchun Song
2021-05-11 10:46 ` [PATCH 11/17] mm: dcache: use kmem_cache_alloc_lru() to allocate dentry Muchun Song
2021-05-11 10:46 ` [PATCH 12/17] xarray: replace kmem_cache_alloc with kmem_cache_alloc_lru Muchun Song
2021-05-11 10:46 ` [PATCH 13/17] mm: workingset: allocate list_lru on xa_node allocation Muchun Song
2021-05-11 10:46 ` [PATCH 14/17] nfs42: use a specific kmem_cache to allocate nfs4_xattr_entry Muchun Song
2021-05-11 10:46 ` [PATCH 15/17] mm: list_lru: allocate list_lru_one only when needed Muchun Song
2021-05-11 10:46 ` [PATCH 16/17] mm: list_lru: rename memcg_drain_all_list_lrus to memcg_reparent_list_lrus Muchun Song
2021-05-11 10:46 ` [PATCH 17/17] mm: list_lru: replace linear array with xarray Muchun Song

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