Documentation: memcg: future proof hierarchical statistics documentation

The hierarchical versions of per-memcg counters in memory.stat are all
calculated the same way and are all named total_<counter>.

Documenting the pattern is easier for maintenance than listing each
counter twice.

Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Acked-by: Michal Hocko <mhocko@suse.cz>
Acked-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Acked-by: Ying Han <yinghan@google.com>
Randy Dunlap <rdunlap@xenotime.net>
Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 4 insertions, 11 deletions

diff --git a/Documentation/cgroups/memory.txt b/Documentation/cgroups/memory.txt
index 9b1067afb224..e479007f1a75 100644
--- a/Documentation/cgroups/memory.txt
+++ b/Documentation/cgroups/memory.txt
@@ -430,17 +430,10 @@ hierarchical_memory_limit - # of bytes of memory limit with regard to hierarchy
 hierarchical_memsw_limit - # of bytes of memory+swap limit with regard to
                         hierarchy under which memory cgroup is.
 
-total_cache             - sum of all children's "cache"
-total_rss               - sum of all children's "rss"
-total_mapped_file       - sum of all children's "cache"
-total_pgpgin            - sum of all children's "pgpgin"
-total_pgpgout           - sum of all children's "pgpgout"
-total_swap              - sum of all children's "swap"
-total_inactive_anon     - sum of all children's "inactive_anon"
-total_active_anon       - sum of all children's "active_anon"
-total_inactive_file     - sum of all children's "inactive_file"
-total_active_file       - sum of all children's "active_file"
-total_unevictable       - sum of all children's "unevictable"
+total_<counter>         - # hierarchical version of <counter>, which in
+                        addition to the cgroup's own value includes the
+                        sum of all hierarchical children's values of
+                        <counter>, i.e. total_cache
 
 # The following additional stats are dependent on CONFIG_DEBUG_VM.