Files
kernel_arpi/include/linux
KAMEZAWA Hiroyuki 8725d54162 memcg: fix race in file_mapped accounting
Presently, memcg's FILE_MAPPED accounting has following race with
move_account (happens at rmdir()).

    increment page->mapcount (rmap.c)
    mem_cgroup_update_file_mapped()           move_account()
					      lock_page_cgroup()
					      check page_mapped() if
					      page_mapped(page)>1 {
						FILE_MAPPED -1 from old memcg
						FILE_MAPPED +1 to old memcg
					      }
					      .....
					      overwrite pc->mem_cgroup
					      unlock_page_cgroup()
    lock_page_cgroup()
    FILE_MAPPED + 1 to pc->mem_cgroup
    unlock_page_cgroup()

Then,
	old memcg (-1 file mapped)
	new memcg (+2 file mapped)

This happens because move_account see page_mapped() which is not guarded
by lock_page_cgroup().  This patch adds FILE_MAPPED flag to page_cgroup
and move account information based on it.  Now, all checks are synchronous
with lock_page_cgroup().

Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Reviewed-by: Balbir Singh <balbir@in.ibm.com>
Reviewed-by: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp>
Cc: Andrea Righi <arighi@develer.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-04-07 08:38:05 -07:00
..
2010-03-12 15:53:10 -08:00
2010-03-01 15:11:32 -05:00
2010-03-12 15:52:32 -08:00
2010-02-05 07:35:05 -08:00
2009-12-23 13:33:54 +01:00
2010-02-09 11:13:56 +01:00
2010-03-07 22:17:09 +01:00
2010-03-02 12:23:42 +01:00
2010-03-02 12:23:49 +01:00
2010-01-19 01:52:36 -08:00
2010-02-18 14:08:38 -08:00
2010-02-17 16:35:17 -08:00
2010-02-02 07:32:29 -08:00
2010-01-11 16:28:01 -08:00
2010-03-12 15:52:40 -08:00
2010-03-12 15:52:36 -08:00
2010-03-12 15:52:40 -08:00
2010-03-12 15:53:10 -08:00
2010-04-06 10:55:33 -04:00
2009-12-26 20:40:34 -08:00
2010-02-03 17:39:50 +11:00
2010-03-12 15:53:10 -08:00
2010-02-09 11:13:56 +01:00
2010-02-19 03:35:12 -05:00
2010-03-12 15:52:38 -08:00
2010-03-12 15:52:28 -08:00
2010-04-07 08:38:04 -07:00
2010-02-10 23:49:08 +09:00
2010-02-03 20:32:28 -08:00
2010-02-19 15:52:40 -05:00
2010-02-14 07:13:47 -07:00
2010-02-23 23:14:47 -08:00
2010-02-04 10:23:02 -08:00
2010-03-12 15:53:11 -08:00
2010-03-05 00:20:31 +01:00
2010-02-10 17:47:17 -08:00
2010-03-12 15:52:44 -08:00
2010-03-02 14:28:49 -05:00
2010-03-12 15:53:10 -08:00
2010-03-12 15:52:43 -08:00
2010-01-21 23:55:25 -08:00
2010-02-16 13:38:56 +09:00
2010-03-12 15:52:44 -08:00
2010-01-14 22:38:09 -05:00
2010-03-12 15:52:36 -08:00
2010-02-18 15:43:09 -08:00
2010-01-05 09:17:33 +09:00