memcg: oom: fix totalpages calculation for memory.swappiness==0

[~andy/linux] / Documentation / cgroups / memory.txt

diff --git a/Documentation/cgroups/memory.txt b/Documentation/cgroups/memory.txt
index c07f7b4fb88d162ad012e69a3d77aa90d62868ff..71c4da413444d969519ae464250774db5c05de63 100644 (file)
--- a/Documentation/cgroups/memory.txt
+++ b/Documentation/cgroups/memory.txt
@@ -466,6 +466,10 @@ Note:
 5.3 swappiness
 
 Similar to /proc/sys/vm/swappiness, but affecting a hierarchy of groups only.
+Please note that unlike the global swappiness, memcg knob set to 0
+really prevents from any swapping even if there is a swap storage
+available. This might lead to memcg OOM killer if there are no file
+pages to reclaim.
 
 Following cgroups' swappiness can't be changed.
 - root cgroup (uses /proc/sys/vm/swappiness).