memcg: document cgroup dirty/writeback memory statistics
Signed-off-by: Sha Zhengju <handai.szj@taobao.com>
Cc: Fengguang Wu <fengguang.wu@intel.com>
Cc: Greg Thelen <gthelen@google.com>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Michal Hocko <mhocko@suse.cz>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/Documentation/cgroups/memory.txt b/Documentation/cgroups/memory.txt
index 2a33306..8af4ad1 100644
--- a/Documentation/cgroups/memory.txt
+++ b/Documentation/cgroups/memory.txt
@@ -490,6 +490,8 @@
pgpgout - # of uncharging events to the memory cgroup. The uncharging
event happens each time a page is unaccounted from the cgroup.
swap - # of bytes of swap usage
+writeback - # of bytes of file/anon cache that are queued for syncing to
+ disk.
inactive_anon - # of bytes of anonymous and swap cache memory on inactive
LRU list.
active_anon - # of bytes of anonymous and swap cache memory on active