memcg: move charges of anonymous swap
commit024914477e15ef8b17f271ec47f1bb8a589f0806
authorDaisuke Nishimura <nishimura@mxp.nes.nec.co.jp>
Wed, 10 Mar 2010 23:22:17 +0000 (10 15:22 -0800)
committerLinus Torvalds <torvalds@linux-foundation.org>
Fri, 12 Mar 2010 23:52:36 +0000 (12 15:52 -0800)
tree9a6a8b4224c94fcdd1b8c3127b301ee3537f8cc2
parent8033b97c9b5ef063e3f4bf2efe1cd0a22093aaff
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>
Documentation/cgroups/memory.txt
include/linux/page_cgroup.h
include/linux/swap.h
mm/memcontrol.c
mm/page_cgroup.c
mm/swapfile.c