From 2a13515c398bbe471bf64519ada87fd708152ced Mon Sep 17 00:00:00 2001 From: KOSAKI Motohiro Date: Tue, 31 Jul 2012 16:42:53 -0700 Subject: [PATCH] mm: clear pages_scanned only if draining a pcp adds pages to the buddy allocator again commit 2ff754fa8f ("mm: clear pages_scanned only if draining a pcp adds pages to the buddy allocator again") fixed one free_pcppages_bulk() misuse. But two another miuse still exist. This patch fixes it. Signed-off-by: KOSAKI Motohiro Acked-by: David Rientjes Acked-by: Mel Gorman Acked-by: Johannes Weiner Reviewed-by: Minchan Kim Cc: Wu Fengguang Reviewed-by: KAMEZAWA Hiroyuki Cc: Rik van Riel Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- mm/page_alloc.c | 9 ++++++--- 1 file changed, 6 insertions(+), 3 deletions(-) diff --git a/mm/page_alloc.c b/mm/page_alloc.c index 80ef99234b89eb..18747528eec3a0 100644 --- a/mm/page_alloc.c +++ b/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); }