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| author | Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp> | 2010-03-11 00:22:17 +0100 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2010-03-13 00:52:36 +0100 |
| commit | 024914477e15ef8b17f271ec47f1bb8a589f0806 (patch) | |
| tree | 9a6a8b4224c94fcdd1b8c3127b301ee3537f8cc2 /Documentation/cgroups | |
| parent | memcg: avoid oom during moving charge (diff) | |
| download | linux-024914477e15ef8b17f271ec47f1bb8a589f0806.tar.xz linux-024914477e15ef8b17f271ec47f1bb8a589f0806.zip | |
memcg: move charges of anonymous swap
This patch is another core part of this move-charge-at-task-migration
feature. It enables moving charges of anonymous swaps.
To move the charge of swap, we need to exchange swap_cgroup's record.
In current implementation, swap_cgroup's record is protected by:
- page lock: if the entry is on swap cache.
- swap_lock: if the entry is not on swap cache.
This works well in usual swap-in/out activity.
But this behavior make the feature of moving swap charge check many
conditions to exchange swap_cgroup's record safely.
So I changed modification of swap_cgroup's recored(swap_cgroup_record())
to use xchg, and define a new function to cmpxchg swap_cgroup's record.
This patch also enables moving charge of non pte_present but not uncharged
swap caches, which can be exist on swap-out path, by getting the target
pages via find_get_page() as do_mincore() does.
[kosaki.motohiro@jp.fujitsu.com: fix ia64 build]
[akpm@linux-foundation.org: fix typos]
Signed-off-by: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp>
Cc: Balbir Singh <balbir@linux.vnet.ibm.com>
Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Li Zefan <lizf@cn.fujitsu.com>
Cc: Paul Menage <menage@google.com>
Cc: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp>
Signed-off-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.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.txt | 2 |
1 files changed, 2 insertions, 0 deletions
diff --git a/Documentation/cgroups/memory.txt b/Documentation/cgroups/memory.txt index e726fb0df719..1f59a1a38bd9 100644 --- a/Documentation/cgroups/memory.txt +++ b/Documentation/cgroups/memory.txt @@ -420,6 +420,8 @@ NOTE2: It is recommended to set the soft limit always below the hard limit, Users can move charges associated with a task along with task migration, that is, uncharge task's pages from the old cgroup and charge them to the new cgroup. +This feature is not supported in !CONFIG_MMU environments because of lack of +page tables. 8.1 Interface |