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| author | Kirill A. Shutemov <kirill@shutemov.name> | 2010-03-11 00:22:24 +0100 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2010-03-13 00:52:37 +0100 |
| commit | 2e72b6347c9459e6cff5634ddc815485bae6985f (patch) | |
| tree | 48ceef47f2cd0d33f2a1dd816c1a05ca2cb3e0e2 /Documentation | |
| parent | memcg: rework usage of stats by soft limit (diff) | |
| download | linux-2e72b6347c9459e6cff5634ddc815485bae6985f.tar.xz linux-2e72b6347c9459e6cff5634ddc815485bae6985f.zip | |
memcg: implement memory thresholds
It allows to register multiple memory and memsw thresholds and gets
notifications when it crosses.
To register a threshold application need:
- create an eventfd;
- open memory.usage_in_bytes or memory.memsw.usage_in_bytes;
- write string like "<event_fd> <memory.usage_in_bytes> <threshold>" to
cgroup.event_control.
Application will be notified through eventfd when memory usage crosses
threshold in any direction.
It's applicable for root and non-root cgroup.
It uses stats to track memory usage, simmilar to soft limits. It checks
if we need to send event to userspace on every 100 page in/out. I guess
it's good compromise between performance and accuracy of thresholds.
[akpm@linux-foundation.org: coding-style fixes]
[nishimura@mxp.nes.nec.co.jp: fix documentation merge issue]
Signed-off-by: Kirill A. Shutemov <kirill@shutemov.name>
Cc: Li Zefan <lizf@cn.fujitsu.com>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Balbir Singh <balbir@linux.vnet.ibm.com>
Cc: Pavel Emelyanov <xemul@openvz.org>
Cc: Dan Malek <dan@embeddedalley.com>
Cc: Vladislav Buzov <vbuzov@embeddedalley.com>
Cc: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp>
Cc: Alexander Shishkin <virtuoso@slind.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'Documentation')
| -rw-r--r-- | Documentation/cgroups/memory.txt | 19 |
1 files changed, 18 insertions, 1 deletions
diff --git a/Documentation/cgroups/memory.txt b/Documentation/cgroups/memory.txt index 1f59a1a38bd9..268ab08222dd 100644 --- a/Documentation/cgroups/memory.txt +++ b/Documentation/cgroups/memory.txt @@ -468,7 +468,24 @@ Note: More type of pages(e.g. file cache, shmem,) will be supported by other - All of moving charge operations are done under cgroup_mutex. It's not good behavior to hold the mutex too long, so we may need some trick. -9. TODO +9. Memory thresholds + +Memory controler implements memory thresholds using cgroups notification +API (see cgroups.txt). It allows to register multiple memory and memsw +thresholds and gets notifications when it crosses. + +To register a threshold application need: + - create an eventfd using eventfd(2); + - open memory.usage_in_bytes or memory.memsw.usage_in_bytes; + - write string like "<event_fd> <memory.usage_in_bytes> <threshold>" to + cgroup.event_control. + +Application will be notified through eventfd when memory usage crosses +threshold in any direction. + +It's applicable for root and non-root cgroup. + +10. TODO 1. Add support for accounting huge pages (as a separate controller) 2. Make per-cgroup scanner reclaim not-shared pages first |