mm: clear pages_scanned only if draining a pcp adds pages to the budd…

…y allocator again commit 2ff754f ("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 <[email protected]> Acked-by: David Rientjes <[email protected]> Acked-by: Mel Gorman <[email protected]> Acked-by: Johannes Weiner <[email protected]> Reviewed-by: Minchan Kim <[email protected]> Cc: Wu Fengguang <[email protected]> Reviewed-by: KAMEZAWA Hiroyuki <[email protected]> Cc: Rik van Riel <[email protected]> Signed-off-by: Andrew Morton <[email protected]> Signed-off-by: Linus Torvalds <[email protected]>
mna · Aug 1, 2012 · 2a13515 · 2a13515
1 parent 3d3727c
commit 2a13515
Showing 1 changed file with 6 additions and 3 deletions.
diff --git 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);
 	}