memcg: add documentation for the memory.numastat API

[akpm@linux-foundation.org: rework text, fit it into 80-cols]
Signed-off-by: Ying Han <yinghan@google.com>
Reviewed-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Acked-by: Balbir Singh <bsingharora@gmail.com>
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>
This commit is contained in:
Ying Han 2011-06-15 15:08:16 -07:00 committed by Linus Torvalds
parent d7911ef30c
commit 50c35e5ba2

View File

@ -70,6 +70,7 @@ Brief summary of control files.
(See sysctl's vm.swappiness)
memory.move_charge_at_immigrate # set/show controls of moving charges
memory.oom_control # set/show oom controls.
memory.numa_stat # show the number of memory usage per numa node
1. History
@ -464,6 +465,24 @@ 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 operates on a per-memcg basis. This is
useful for providing visibility into the numa locality information within
an memcg since the pages are allowed to be allocated from any physical
node. One of the usecases is evaluating application performance by
combining this information with the application's cpu allocation.
We export "total", "file", "anon" and "unevictable" pages per-node for
each memcg. The ouput format of memory.numa_stat is:
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.
6. Hierarchy support
The memory controller supports a deep hierarchy and hierarchical accounting.