Commit e6ca7b89 authored Mar 05, 2012 by Naoya Horiguchi Committed by Linus Torvalds Mar 05, 2012

memcg: fix mapcount check in move charge code for anonymous page

Currently the charge on shared anonyous pages is supposed not to moved in
task migration.  To implement this, we need to check that mapcount > 1,
instread of > 2.  So this patch fixes it.

Signed-off-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Reviewed-by: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Hillf Danton <dhillf@gmail.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

parent 1c641e84

mm/memcontrol.c

+1 −1

Original line number	Diff line number	Diff line
		@@ -5075,7 +5075,7 @@ static struct page mc_handle_present_pte(struct vm_area_struct vma,
		return NULL;
		if (PageAnon(page)) {
		/* we don't move shared anon */
		if (!move_anon() \|\| page_mapcount(page) > 2)
		if (!move_anon() \|\| page_mapcount(page) > 1)
		return NULL;
		} else if (!move_file())
		/* we ignore mapcount for file pages */

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