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author | KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> | 2008-07-25 01:47:17 -0700 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2008-07-25 10:53:37 -0700 |
commit | accf163e6ab729f1fc5fffaa0310e498270bf4e7 (patch) | |
tree | 798d5c97aa10bd26018fb1175a176c9d57560a39 /include/linux/delay.h | |
parent | b76734e5e34e1889ab9fc5f3756570b1129f0f50 (diff) |
memcg: remove a redundant check
Because of remove refcnt patch, it's very rare case to that
mem_cgroup_charge_common() is called against a page which is accounted.
mem_cgroup_charge_common() is called when.
1. a page is added into file cache.
2. an anon page is _newly_ mapped.
A racy case is that a newly-swapped-in anonymous page is referred from
prural threads in do_swap_page() at the same time.
(a page is not Locked when mem_cgroup_charge() is called from do_swap_page.)
Another case is shmem. It charges its page before calling add_to_page_cache().
Then, mem_cgroup_charge_cache() is called twice. This case is handled in
mem_cgroup_cache_charge(). But this check may be too hacky...
Signed-off-by : KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Balbir Singh <balbir@in.ibm.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Pavel Emelyanov <xemul@openvz.org>
Cc: Li Zefan <lizf@cn.fujitsu.com>
Cc: Hugh Dickins <hugh@veritas.com>
Cc: YAMAMOTO Takashi <yamamoto@valinux.co.jp>
Cc: Paul Menage <menage@google.com>
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 'include/linux/delay.h')
0 files changed, 0 insertions, 0 deletions