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memcg: move charge swapin under lock

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While page-cache's charge/uncharge is done under page_lock(), swap-cache
isn't.  (anonymous page is charged when it's newly allocated.)

This patch moves do_swap_page()'s charge() call under lock.  I don't see
any bad problem *now* but this fix will be good for future for avoiding
unnecessary racy state.

Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Reviewed-by: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp>
Acked-by: Balbir Singh <balbir@linux.vnet.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
KAMEZAWA Hiroyuki 2008-10-18 20:28:08 -07:00 committed by Linus Torvalds
parent 47c59803be
commit 073e587ec2
1 changed files with 7 additions and 6 deletions
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13
mm/memory.c
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@ -2326,16 +2326,17 @@ static int do_swap_page(struct mm_struct *mm, struct vm_area_struct *vma,
count_vm_event(PGMAJFAULT);
}
if (mem_cgroup_charge(page, mm, GFP_KERNEL)) {
delayacct_clear_flag(DELAYACCT_PF_SWAPIN);
ret = VM_FAULT_OOM;
goto out;
}
mark_page_accessed(page);
lock_page(page);
delayacct_clear_flag(DELAYACCT_PF_SWAPIN);
if (mem_cgroup_charge(page, mm, GFP_KERNEL)) {
ret = VM_FAULT_OOM;
unlock_page(page);
goto out;
}
/*
* Back out if somebody else already faulted in this pte.
*/