From: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>

If zone->recent_scanned parameter become inbalanceing anon and file, OOM
killer can happened although swappable page exist.

So, if priority==0, We should try to reclaim all page for prevent OOM.

Signed-off-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Acked-by: Rik van Riel <riel@redhat.com>
Cc: Lee Schermerhorn <lee.schermerhorn@hp.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

 mm/vmscan.c |    6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff -puN mm/vmscan.c~vmscan-split-lru-lists-into-anon-file-sets-prevent-incorrect-oom-under-split_lru mm/vmscan.c
--- a/mm/vmscan.c~vmscan-split-lru-lists-into-anon-file-sets-prevent-incorrect-oom-under-split_lru
+++ a/mm/vmscan.c
@@ -1292,8 +1292,10 @@ static unsigned long shrink_zone(int pri
 			 * kernel will slowly sift through each list.
 			 */
 			scan = zone_page_state(zone, NR_LRU_BASE + l);
-			scan >>= priority;
-			scan = (scan * percent[file]) / 100;
+			if (priority) {
+				scan >>= priority;
+				scan = (scan * percent[file]) / 100;
+			}
 			zone->lru[l].nr_scan += scan + 1;
 			nr[l] = zone->lru[l].nr_scan;
 			if (nr[l] >= sc->swap_cluster_max)
_