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

[Naoya Horiguchi]

Currently 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@xxxxxxxxxxxxx>
---
 mm/memcontrol.c |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)

diff --git linux-next-20120228.orig/mm/memcontrol.c linux-next-20120228/mm/memcontrol.c
index b6d1bab..785f6d3 100644
--- linux-next-20120228.orig/mm/memcontrol.c
+++ linux-next-20120228/mm/memcontrol.c
@@ -5102,7 +5102,7 @@ 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 */
-- 
1.7.7.6

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