mm: per-cgroup memory reclaim stats

Track the following reclaim counters for every memory cgroup: PGREFILL,
PGSCAN, PGSTEAL, PGACTIVATE, PGDEACTIVATE, PGLAZYFREE and PGLAZYFREED.

These values are exposed using the memory.stats interface of cgroup v2.

The meaning of each value is the same as for global counters, available
using /proc/vmstat.

Also, for consistency, rename mem_cgroup_count_vm_event() to
count_memcg_event_mm().

Link: http://lkml.kernel.org/r/1494530183-30808-1-git-send-email-guro@fb.com
Signed-off-by: Roman Gushchin <guro@fb.com>
Suggested-by: Johannes Weiner <hannes@cmpxchg.org>
Acked-by: Michal Hocko <mhocko@suse.com>
Acked-by: Vladimir Davydov <vdavydov.dev@gmail.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Cc: Tejun Heo <tj@kernel.org>
Cc: Li Zefan <lizefan@huawei.com>
Cc: Balbir Singh <bsingharora@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 28 insertions, 0 deletions

diff --git a/Documentation/cgroup-v2.txt b/Documentation/cgroup-v2.txt
index 558c3a739baf..5ac2fbde97e6 100644
--- a/Documentation/cgroup-v2.txt
+++ b/Documentation/cgroup-v2.txt
@@ -956,6 +956,34 @@ PAGE_SIZE multiple when read back.
 
 		Number of times a shadow node has been reclaimed
 
+	  pgrefill
+
+		Amount of scanned pages (in an active LRU list)
+
+	  pgscan
+
+		Amount of scanned pages (in an inactive LRU list)
+
+	  pgsteal
+
+		Amount of reclaimed pages
+
+	  pgactivate
+
+		Amount of pages moved to the active LRU list
+
+	  pgdeactivate
+
+		Amount of pages moved to the inactive LRU lis
+
+	  pglazyfree
+
+		Amount of pages postponed to be freed under memory pressure
+
+	  pglazyfreed
+
+		Amount of reclaimed lazyfree pages
+
   memory.swap.current
 
 	A read-only single value file which exists on non-root