This series is based on Linux v5.17-rc5. And I have replaced Roman's email
in Acked-by and Reviewed-by tags to [email protected].
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. It leads to 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
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.
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 (There are 2 numa nodes
in the system).
+-----------------------+------------------------+
| condition | memory consumption |
+-----------------------+------------------------+
| without this patchset | 24464 MB |
+-----------------------+------------------------+
| after patch 1 | 21957 MB | <--------+
+-----------------------+------------------------+ |
| after patch 10 | 6895 MB | |
+-----------------------+------------------------+ |
| after patch 12 | 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/all/[email protected]/
[2] https://lore.kernel.org/all/[email protected]/
This series not only optimizes the memory usage of list_lru but also
simplifies the code.
v5: https://lore.kernel.org/all/[email protected]/
v4: https://lore.kernel.org/all/[email protected]/
v3: https://lore.kernel.org/all/[email protected]/
v2: https://lore.kernel.org/all/[email protected]/
v1: https://lore.kernel.org/all/[email protected]/
v6:
- Collect Acked-by from Roman and replace his old email with
[email protected].
- Rework patch 1's commit log suggested by Roman.
- Reuse memory cgroup ID for kmem ID directly suggested by Mika Penttilä.
- Add a couple of words to Documentation/filesystems/porting.rst suggested
by Roman.
Thanks for your review.
v5:
- Fix sleeping from atomic context reported by kernel test robot.
- Add a figure to patch 1 suggested by Johannes.
- Squash patch 9 into patch 8 suggested by Johannes.
- Remove LRUS_CLEAR_MASK and use GFP_RECLAIM_MASK directly suggested
by Johannes.
- Collect Acked-by from Johannes.
v4:
- Remove some code cleanup patches since they are already merged.
- Collect Acked-by from Theodore.
v3:
- Fix mixing advanced and normal XArray concepts (Thanks to Matthew).
- Split one patch into per-filesystem patches.
v2:
- Update Documentation/filesystems/porting.rst suggested by Dave.
- Add a comment above alloc_inode_sb() suggested by Dave.
- Rework some patch's commit log.
- Add patch 18-21.
Muchun Song (16):
mm: list_lru: transpose the array of per-node per-memcg lru lists
mm: introduce kmem_cache_alloc_lru
fs: introduce alloc_inode_sb() to allocate filesystems specific inode
fs: allocate inode by using alloc_inode_sb()
f2fs: allocate inode by using alloc_inode_sb()
nfs42: use a specific kmem_cache to allocate nfs4_xattr_entry
mm: dcache: use kmem_cache_alloc_lru() to allocate dentry
xarray: use kmem_cache_alloc_lru to allocate xa_node
mm: memcontrol: move memcg_online_kmem() to mem_cgroup_css_online()
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
mm: memcontrol: reuse memory cgroup ID for kmem ID
mm: memcontrol: fix cannot alloc the maximum memcg ID
mm: list_lru: rename list_lru_per_memcg to list_lru_memcg
mm: memcontrol: rename memcg_cache_id to memcg_kmem_id
Documentation/filesystems/porting.rst | 6 +
block/bdev.c | 2 +-
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/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 | 8 +-
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/ntfs3/super.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 | 2 +-
fs/zonefs/super.c | 2 +-
include/linux/fs.h | 11 +
include/linux/list_lru.h | 17 +-
include/linux/memcontrol.h | 41 ++--
include/linux/slab.h | 3 +
include/linux/swap.h | 5 +-
include/linux/xarray.h | 9 +-
ipc/mqueue.c | 2 +-
lib/xarray.c | 10 +-
mm/list_lru.c | 417 ++++++++++++++++------------------
mm/memcontrol.c | 160 ++-----------
mm/shmem.c | 2 +-
mm/slab.c | 39 +++-
mm/slab.h | 25 +-
mm/slob.c | 6 +
mm/slub.c | 42 ++--
mm/workingset.c | 2 +-
net/socket.c | 2 +-
net/sunrpc/rpc_pipe.c | 2 +-
76 files changed, 476 insertions(+), 539 deletions(-)
--
2.11.0
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 list_lru_one allocation is ready, so
remove statically allocated memory code to save memory.
Signed-off-by: Muchun Song <[email protected]>
---
include/linux/list_lru.h | 7 +--
mm/list_lru.c | 121 ++++++++++++++++++++++++++---------------------
mm/memcontrol.c | 6 ++-
3 files changed, 77 insertions(+), 57 deletions(-)
diff --git a/include/linux/list_lru.h b/include/linux/list_lru.h
index ab912c49334f..c36db6dc2a65 100644
--- a/include/linux/list_lru.h
+++ b/include/linux/list_lru.h
@@ -32,14 +32,15 @@ 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 node[0];
+ struct list_lru_one node[];
};
struct list_lru_memcg {
struct rcu_head rcu;
/* array of per cgroup lists, indexed by memcg_cache_id */
- struct list_lru_per_memcg *mlru[];
+ struct list_lru_per_memcg __rcu *mlru[];
};
struct list_lru_node {
@@ -77,7 +78,7 @@ int __list_lru_init(struct list_lru *lru, bool memcg_aware,
int memcg_list_lru_alloc(struct mem_cgroup *memcg, struct list_lru *lru,
gfp_t gfp);
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, struct mem_cgroup *dst);
/**
* 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 bffa80527723..fc938d8ff48f 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)
* from relocation (see memcg_update_list_lru).
*/
mlrus = rcu_dereference_check(lru->mlrus, lockdep_is_held(&nlru->lock));
- if (mlrus && idx >= 0)
- return &mlrus->mlru[idx]->node[nid];
+ if (mlrus && idx >= 0) {
+ struct list_lru_per_memcg *mlru;
+
+ mlru = rcu_dereference_check(mlrus->mlru[idx], true);
+ return mlru ? &mlru->node[nid] : NULL;
+ }
return &nlru->lru;
}
@@ -188,7 +192,7 @@ unsigned long list_lru_count_one(struct list_lru *lru,
rcu_read_lock();
l = list_lru_from_memcg_idx(lru, nid, memcg_cache_id(memcg));
- count = READ_ONCE(l->nr_items);
+ count = l ? READ_ONCE(l->nr_items) : 0;
rcu_read_unlock();
if (unlikely(count < 0))
@@ -217,8 +221,11 @@ __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 +269,7 @@ __list_lru_walk_one(struct list_lru *lru, int nid, int memcg_idx,
BUG();
}
}
+out:
return isolated;
}
@@ -354,20 +362,25 @@ static struct list_lru_per_memcg *memcg_init_list_lru_one(gfp_t gfp)
return mlru;
}
-static int memcg_init_list_lru_range(struct list_lru_memcg *mlrus,
- int begin, int end)
+static void memcg_list_lru_free(struct list_lru *lru, int src_idx)
{
- int i;
+ struct list_lru_memcg *mlrus;
+ struct list_lru_per_memcg *mlru;
- for (i = begin; i < end; i++) {
- mlrus->mlru[i] = memcg_init_list_lru_one(GFP_KERNEL);
- if (!mlrus->mlru[i])
- goto fail;
- }
- return 0;
-fail:
- memcg_destroy_list_lru_range(mlrus, begin, i);
- return -ENOMEM;
+ spin_lock_irq(&lru->lock);
+ mlrus = rcu_dereference_protected(lru->mlrus, true);
+ mlru = rcu_dereference_protected(mlrus->mlru[src_idx], true);
+ rcu_assign_pointer(mlrus->mlru[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 int memcg_init_list_lru(struct list_lru *lru, bool memcg_aware)
@@ -381,14 +394,10 @@ static int memcg_init_list_lru(struct list_lru *lru, bool memcg_aware)
spin_lock_init(&lru->lock);
- mlrus = kvmalloc(struct_size(mlrus, mlru, size), GFP_KERNEL);
+ mlrus = kvzalloc(struct_size(mlrus, mlru, size), GFP_KERNEL);
if (!mlrus)
return -ENOMEM;
- if (memcg_init_list_lru_range(mlrus, 0, size)) {
- kvfree(mlrus);
- return -ENOMEM;
- }
RCU_INIT_POINTER(lru->mlrus, mlrus);
return 0;
@@ -422,13 +431,9 @@ 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->mlru, &old->mlru, flex_array_size(new, mlru, old_size));
+ memset(&new->mlru[old_size], 0, flex_array_size(new, mlru, new_size - old_size));
rcu_assign_pointer(lru->mlrus, new);
spin_unlock_irq(&lru->lock);
@@ -436,20 +441,6 @@ 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 *mlrus;
-
- mlrus = rcu_dereference_protected(lru->mlrus,
- 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(mlrus, old_size, new_size);
-}
-
int memcg_update_all_list_lrus(int new_size)
{
int ret = 0;
@@ -460,15 +451,10 @@ int memcg_update_all_list_lrus(int new_size)
list_for_each_entry(lru, &memcg_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, &memcg_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,
@@ -485,6 +471,8 @@ 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);
@@ -494,7 +482,7 @@ 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);
}
@@ -505,15 +493,41 @@ 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);
+
+ memcg_list_lru_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, struct mem_cgroup *dst)
{
+ struct cgroup_subsys_state *css;
struct list_lru *lru;
+ int src_idx = src->kmemcg_id;
+
+ /*
+ * 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. So we can safely free this cgroup's
+ * list lrus in memcg_list_lru_free().
+ *
+ * Changing ->kmemcg_id to the parent can prevent memcg_list_lru_alloc()
+ * from allocating list lrus for this cgroup after memcg_list_lru_free()
+ * call.
+ */
+ rcu_read_lock();
+ css_for_each_descendant_pre(css, &src->css) {
+ struct mem_cgroup *memcg;
+
+ memcg = mem_cgroup_from_css(css);
+ memcg->kmemcg_id = dst->kmemcg_id;
+ }
+ rcu_read_unlock();
mutex_lock(&list_lrus_mutex);
list_for_each_entry(lru, &memcg_list_lrus, list)
- memcg_drain_list_lru(lru, src_idx, dst_memcg);
+ memcg_drain_list_lru(lru, src_idx, dst);
mutex_unlock(&list_lrus_mutex);
}
@@ -528,7 +542,7 @@ static bool memcg_list_lru_allocated(struct mem_cgroup *memcg,
return true;
rcu_read_lock();
- allocated = !!rcu_dereference(lru->mlrus)->mlru[idx];
+ allocated = !!rcu_access_pointer(rcu_dereference(lru->mlrus)->mlru[idx]);
rcu_read_unlock();
return allocated;
@@ -576,11 +590,12 @@ int memcg_list_lru_alloc(struct mem_cgroup *memcg, struct list_lru *lru,
mlrus = rcu_dereference_protected(lru->mlrus, true);
while (i--) {
int index = table[i].memcg->kmemcg_id;
+ struct list_lru_per_memcg *mlru = table[i].mlru;
- if (mlrus->mlru[index])
- kfree(table[i].mlru);
+ if (index < 0 || rcu_dereference_protected(mlrus->mlru[index], true))
+ kfree(mlru);
else
- mlrus->mlru[index] = table[i].mlru;
+ rcu_assign_pointer(mlrus->mlru[index], mlru);
}
spin_unlock_irqrestore(&lru->lock, flags);
diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index 5bdf5184681c..c8d39d7fc2e5 100644
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -3655,6 +3655,10 @@ 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 local @kmemcg_id.
+ */
kmemcg_id = memcg->kmemcg_id;
/*
@@ -3663,7 +3667,7 @@ static void memcg_offline_kmem(struct mem_cgroup *memcg)
* The ordering is imposed by list_lru_node->lock taken by
* memcg_drain_all_list_lrus().
*/
- memcg_drain_all_list_lrus(kmemcg_id, parent);
+ memcg_drain_all_list_lrus(memcg, parent);
memcg_free_cache_id(kmemcg_id);
}
--
2.11.0
The allocated inode cache is supposed to be added to its memcg list_lru
which should be allocated as well in advance. That can be done by
kmem_cache_alloc_lru() which allocates object and list_lru. The file
systems is main user of it. So introduce alloc_inode_sb() to allocate
file system specific inodes and set up the inode reclaim context
properly. The file system is supposed to use alloc_inode_sb() to
allocate inodes. In the later patches, we will convert all users to the
new API.
Signed-off-by: Muchun Song <[email protected]>
Reviewed-by: Roman Gushchin <[email protected]>
---
Documentation/filesystems/porting.rst | 6 ++++++
fs/inode.c | 2 +-
include/linux/fs.h | 11 +++++++++++
3 files changed, 18 insertions(+), 1 deletion(-)
diff --git a/Documentation/filesystems/porting.rst b/Documentation/filesystems/porting.rst
index bf19fd6b86e7..7c1583dbeb59 100644
--- a/Documentation/filesystems/porting.rst
+++ b/Documentation/filesystems/porting.rst
@@ -45,6 +45,12 @@ typically between calling iget_locked() and unlocking the inode.
At some point that will become mandatory.
+**mandatory**
+
+The foo_inode_info should always be allocated through alloc_inode_sb() rather
+than kmem_cache_alloc() or kmalloc() related to set up the inode reclaim context
+correctly.
+
---
**mandatory**
diff --git a/fs/inode.c b/fs/inode.c
index 63324df6fa27..9d9b422504d1 100644
--- a/fs/inode.c
+++ b/fs/inode.c
@@ -259,7 +259,7 @@ 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/include/linux/fs.h b/include/linux/fs.h
index e2d892b201b0..3d56b02667f4 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -42,6 +42,7 @@
#include <linux/mount.h>
#include <linux/cred.h>
#include <linux/mnt_idmapping.h>
+#include <linux/slab.h>
#include <asm/byteorder.h>
#include <uapi/linux/fs.h>
@@ -3108,6 +3109,16 @@ extern void free_inode_nonrcu(struct inode *inode);
extern int should_remove_suid(struct dentry *);
extern int file_remove_privs(struct file *);
+/*
+ * This must be used for allocating filesystems specific inodes to set
+ * up the inode reclaim context correctly.
+ */
+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)
{
--
2.11.0
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 <[email protected]>
---
include/linux/list_lru.h | 2 +-
mm/list_lru.c | 24 ++++++++++++------------
mm/memcontrol.c | 6 +++---
3 files changed, 16 insertions(+), 16 deletions(-)
diff --git a/include/linux/list_lru.h b/include/linux/list_lru.h
index c36db6dc2a65..4b00fd8cb373 100644
--- a/include/linux/list_lru.h
+++ b/include/linux/list_lru.h
@@ -78,7 +78,7 @@ int __list_lru_init(struct list_lru *lru, bool memcg_aware,
int memcg_list_lru_alloc(struct mem_cgroup *memcg, struct list_lru *lru,
gfp_t gfp);
int memcg_update_all_list_lrus(int num_memcgs);
-void memcg_drain_all_list_lrus(struct mem_cgroup *src, struct mem_cgroup *dst);
+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 fc938d8ff48f..488dacd1f8ff 100644
--- a/mm/list_lru.c
+++ b/mm/list_lru.c
@@ -457,8 +457,8 @@ 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;
@@ -486,22 +486,22 @@ static void memcg_drain_list_lru_node(struct list_lru *lru, int nid,
spin_unlock_irq(&nlru->lock);
}
-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);
memcg_list_lru_free(lru, src_idx);
}
-void memcg_drain_all_list_lrus(struct mem_cgroup *src, struct mem_cgroup *dst)
+void memcg_reparent_list_lrus(struct mem_cgroup *memcg, struct mem_cgroup *parent)
{
struct cgroup_subsys_state *css;
struct list_lru *lru;
- int src_idx = src->kmemcg_id;
+ int src_idx = memcg->kmemcg_id;
/*
* Change kmemcg_id of this cgroup and all its descendants to the
@@ -517,17 +517,17 @@ void memcg_drain_all_list_lrus(struct mem_cgroup *src, struct mem_cgroup *dst)
* call.
*/
rcu_read_lock();
- css_for_each_descendant_pre(css, &src->css) {
- struct mem_cgroup *memcg;
+ css_for_each_descendant_pre(css, &memcg->css) {
+ struct mem_cgroup *child;
- memcg = mem_cgroup_from_css(css);
- memcg->kmemcg_id = dst->kmemcg_id;
+ child = mem_cgroup_from_css(css);
+ child->kmemcg_id = parent->kmemcg_id;
}
rcu_read_unlock();
mutex_lock(&list_lrus_mutex);
list_for_each_entry(lru, &memcg_list_lrus, list)
- memcg_drain_list_lru(lru, src_idx, dst);
+ memcg_reparent_list_lru(lru, src_idx, parent);
mutex_unlock(&list_lrus_mutex);
}
diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index c8d39d7fc2e5..87ee5b431c05 100644
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -3656,7 +3656,7 @@ 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 local @kmemcg_id.
*/
kmemcg_id = memcg->kmemcg_id;
@@ -3665,9 +3665,9 @@ static void memcg_offline_kmem(struct mem_cgroup *memcg)
* After we have finished memcg_reparent_objcgs(), 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().
+ * memcg_reparent_list_lrus().
*/
- memcg_drain_all_list_lrus(memcg, parent);
+ memcg_reparent_list_lrus(memcg, parent);
memcg_free_cache_id(kmemcg_id);
}
--
2.11.0