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authorKAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>2010-05-26 14:42:37 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2010-05-27 09:12:43 -0700
commit3c11ecf448eff8f12922c498b8274ce98587eb74 (patch)
tree0a28aeef7759ead93ff58fd7db2fe61797523f7e /Documentation/cgroups
parent9490ff275606da012d5b373342a49610ad61cb81 (diff)
downloadlinux-linaro-android-3c11ecf448eff8f12922c498b8274ce98587eb74.tar.gz
memcg: oom kill disable and oom status
This adds a feature to disable oom-killer for memcg, if disabled, of course, tasks under memcg will stop. But now, we have oom-notifier for memcg. And the world around memcg is not under out-of-memory. memcg's out-of-memory just shows memcg hits limit. Then, administrator or management daemon can recover the situation by - kill some process - enlarge limit, add more swap. - migrate some tasks - remove file cache on tmps (difficult ?) Unlike oom-killer, you can take enough information before killing tasks. (by gcore, or, ps etc.) [akpm@linux-foundation.org: coding-style fixes] Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp> Cc: Balbir Singh <balbir@in.ibm.com> Cc: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp> Cc: David Rientjes <rientjes@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'Documentation/cgroups')
-rw-r--r--Documentation/cgroups/memory.txt23
1 files changed, 23 insertions, 0 deletions
diff --git a/Documentation/cgroups/memory.txt b/Documentation/cgroups/memory.txt
index eac22d3b2f7..44e7ded3344 100644
--- a/Documentation/cgroups/memory.txt
+++ b/Documentation/cgroups/memory.txt
@@ -493,6 +493,8 @@ It's applicable for root and non-root cgroup.
10. OOM Control
+memory.oom_control file is for OOM notification and other controls.
+
Memory controler implements oom notifier using cgroup notification
API (See cgroups.txt). It allows to register multiple oom notification
delivery and gets notification when oom happens.
@@ -505,6 +507,27 @@ To register a notifier, application need:
Application will be notifier through eventfd when oom happens.
OOM notification doesn't work for root cgroup.
+You can disable oom-killer by writing "1" to memory.oom_control file.
+As.
+ #echo 1 > memory.oom_control
+
+This operation is only allowed to the top cgroup of subhierarchy.
+If oom-killer is disabled, tasks under cgroup will hang/sleep
+in memcg's oom-waitq when they request accountable memory.
+
+For running them, you have to relax the memcg's oom sitaution by
+ * enlarge limit or reduce usage.
+To reduce usage,
+ * kill some tasks.
+ * move some tasks to other group with account migration.
+ * remove some files (on tmpfs?)
+
+Then, stopped tasks will work again.
+
+At reading, current status of OOM is shown.
+ oom_kill_disable 0 or 1 (if 1, oom-killer is disabled)
+ under_oom 0 or 1 (if 1, the memcg is under OOM,tasks may
+ be stopped.)
11. TODO