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authorMuchun Song <songmuchun@bytedance.com>2022-03-22 22:41:19 +0100
committerLinus Torvalds <torvalds@linux-foundation.org>2022-03-22 23:57:03 +0100
commit5abc1e37afa0335c52608d640fd30910b2eeda21 (patch)
treee87df05c9a087219e57e40bda5a614e7812d545c /mm/memcontrol.c
parentmm: memcontrol: move memcg_online_kmem() to mem_cgroup_css_online() (diff)
downloadlinux-5abc1e37afa0335c52608d640fd30910b2eeda21.tar.xz
linux-5abc1e37afa0335c52608d640fd30910b2eeda21.zip
mm: list_lru: allocate list_lru_one only when needed
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. Link: https://lkml.kernel.org/r/20220228122126.37293-11-songmuchun@bytedance.com Signed-off-by: Muchun Song <songmuchun@bytedance.com> Cc: Alex Shi <alexs@kernel.org> Cc: Anna Schumaker <Anna.Schumaker@Netapp.com> Cc: Chao Yu <chao@kernel.org> Cc: Dave Chinner <david@fromorbit.com> Cc: Fam Zheng <fam.zheng@bytedance.com> Cc: Jaegeuk Kim <jaegeuk@kernel.org> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Kari Argillander <kari.argillander@gmail.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Michal Hocko <mhocko@kernel.org> Cc: Qi Zheng <zhengqi.arch@bytedance.com> Cc: Roman Gushchin <roman.gushchin@linux.dev> Cc: Shakeel Butt <shakeelb@google.com> Cc: Theodore Ts'o <tytso@mit.edu> Cc: Trond Myklebust <trond.myklebust@hammerspace.com> Cc: Vladimir Davydov <vdavydov.dev@gmail.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Wei Yang <richard.weiyang@gmail.com> Cc: Xiongchun Duan <duanxiongchun@bytedance.com> Cc: Yang Shi <shy828301@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'mm/memcontrol.c')
-rw-r--r--mm/memcontrol.c6
1 files changed, 5 insertions, 1 deletions
diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index f08a0dc2ac36..69c09efc599d 100644
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -3709,6 +3709,10 @@ 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;
/*
@@ -3717,7 +3721,7 @@ 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);
}