change v2..v1:
1. add sample output.

Signed-off-by: Ying Han <redacted>
---
 Documentation/cgroups/memory.txt |   18 ++++++++++++++++++
 1 files changed, 18 insertions(+), 0 deletions(-)

diff --git a/Documentation/cgroups/memory.txt b/Documentation/cgroups/memory.txt
index 2d7e527..0b1a1ce 100644
--- a/Documentation/cgroups/memory.txt
+++ b/Documentation/cgroups/memory.txt

@@ -71,6 +71,7 @@ Brief summary of control files.
  memory.move_charge_at_immigrate # set/show controls of moving charges
  memory.oom_control		 # set/show oom controls.
  memory.async_control		 # set control for asynchronous memory reclaim
+ memory.numa_stat		 # show the number of memory usage per numa node

 1. History

@@ -477,6 +478,23 @@ value for efficient access. (Of course, when necessary, it's synchronized.)
 If you want to know more exact memory usage, you should use RSS+CACHE(+SWAP)
 value in memory.stat(see 5.2).

+5.6 numa_stat
+
+This is similar to numa_maps but per-memcg basis. This is useful to add visibility
+of numa locality information in memcg since the pages are allowed to be allocated
+at any physical node. One of the usecase is evaluating application performance by
+combining this information with the cpu allocation to the application.
+
+We export "total", "file", "anon" and "unevictable" pages per-node for each memcg.
+The format ouput of the memory.numa_stat:
+
+total=<total pages> N0=<node 0 pages> N1=<node 1 pages> ...
+file=<total file pages> N0=<node 0 pages> N1=<node 1 pages> ...
+anon=<total anon pages> N0=<node 0 pages> N1=<node 1 pages> ...
+unevictable=<total anon pages> N0=<node 0 pages> N1=<node 1 pages> ...
+
+And we have total = file + anon + unevictable.
+