From 5719dad53b8b70c3caa77440fcb6387688f9656b Mon Sep 17 00:00:00 2001
From: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Date: Tue, 31 Jul 2012 16:42:53 -0700
Subject: [PATCH] --- yaml --- r: 320789 b: refs/heads/master c:
 2a13515c398bbe471bf64519ada87fd708152ced h: refs/heads/master i:   320787:
 dd4ee3c10b5c1a076d18d2ae40d87fce1632677f v: v3

---
 [refs]                | 2 +-
 trunk/mm/page_alloc.c | 9 ++++++---
 2 files changed, 7 insertions(+), 4 deletions(-)

diff --git a/[refs] b/[refs]
index d5ddc61f6ce0..a731cd19910a 100644
--- a/[refs]
+++ b/[refs]
@@ -1,2 +1,2 @@
 ---
-refs/heads/master: 3d3727cdb07ff17ddc3c551ef8d03d37b60a0372
+refs/heads/master: 2a13515c398bbe471bf64519ada87fd708152ced
diff --git a/trunk/mm/page_alloc.c b/trunk/mm/page_alloc.c
index 80ef99234b89..18747528eec3 100644
--- a/trunk/mm/page_alloc.c
+++ b/trunk/mm/page_alloc.c
@@ -1158,8 +1158,10 @@ void drain_zone_pages(struct zone *zone, struct per_cpu_pages *pcp)
 		to_drain = pcp->batch;
 	else
 		to_drain = pcp->count;
-	free_pcppages_bulk(zone, to_drain, pcp);
-	pcp->count -= to_drain;
+	if (to_drain > 0) {
+		free_pcppages_bulk(zone, to_drain, pcp);
+		pcp->count -= to_drain;
+	}
 	local_irq_restore(flags);
 }
 #endif
@@ -3915,7 +3917,8 @@ static int __zone_pcp_update(void *data)
 		pcp = &pset->pcp;
 
 		local_irq_save(flags);
-		free_pcppages_bulk(zone, pcp->count, pcp);
+		if (pcp->count > 0)
+			free_pcppages_bulk(zone, pcp->count, pcp);
 		setup_pageset(pset, batch);
 		local_irq_restore(flags);
 	}