Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754091Ab0GHHiT (ORCPT ); Thu, 8 Jul 2010 03:38:19 -0400 Received: from fgwmail5.fujitsu.co.jp ([192.51.44.35]:41469 "EHLO fgwmail5.fujitsu.co.jp" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752094Ab0GHHiQ (ORCPT ); Thu, 8 Jul 2010 03:38:16 -0400 X-SecurityPolicyCheck-FJ: OK by FujitsuOutboundMailChecker v1.3.1 From: KOSAKI Motohiro To: LKML , linux-mm , Andrew Morton , Mel Gorman , Rik van Riel , Minchan Kim , Johannes Weiner Subject: [PATCH v2 1/2] vmscan: don't subtraction of unsined Cc: kosaki.motohiro@jp.fujitsu.com Message-Id: <20100708163401.CD34.A69D9226@jp.fujitsu.com> MIME-Version: 1.0 Content-Type: text/plain; charset="US-ASCII" Content-Transfer-Encoding: 7bit X-Mailer: Becky! ver. 2.50.07 [ja] Date: Thu, 8 Jul 2010 16:38:10 +0900 (JST) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2083 Lines: 64 'slab_reclaimable' and 'nr_pages' are unsigned. so, subtraction is unsafe. Signed-off-by: KOSAKI Motohiro Acked-by: Christoph Lameter --- mm/vmscan.c | 14 +++++++------- 1 files changed, 7 insertions(+), 7 deletions(-) diff --git a/mm/vmscan.c b/mm/vmscan.c index 9c7e57c..8715da1 100644 --- a/mm/vmscan.c +++ b/mm/vmscan.c @@ -2588,7 +2588,7 @@ static int __zone_reclaim(struct zone *zone, gfp_t gfp_mask, unsigned int order) .swappiness = vm_swappiness, .order = order, }; - unsigned long slab_reclaimable; + unsigned long n, m; disable_swap_token(); cond_resched(); @@ -2615,8 +2615,8 @@ static int __zone_reclaim(struct zone *zone, gfp_t gfp_mask, unsigned int order) } while (priority >= 0 && sc.nr_reclaimed < nr_pages); } - slab_reclaimable = zone_page_state(zone, NR_SLAB_RECLAIMABLE); - if (slab_reclaimable > zone->min_slab_pages) { + n = zone_page_state(zone, NR_SLAB_RECLAIMABLE); + if (n > zone->min_slab_pages) { /* * shrink_slab() does not currently allow us to determine how * many pages were freed in this zone. So we take the current @@ -2628,16 +2628,16 @@ static int __zone_reclaim(struct zone *zone, gfp_t gfp_mask, unsigned int order) * take a long time. */ while (shrink_slab(sc.nr_scanned, gfp_mask, order) && - zone_page_state(zone, NR_SLAB_RECLAIMABLE) > - slab_reclaimable - nr_pages) + (zone_page_state(zone, NR_SLAB_RECLAIMABLE) + nr_pages > n)) ; /* * Update nr_reclaimed by the number of slab pages we * reclaimed from this zone. */ - sc.nr_reclaimed += slab_reclaimable - - zone_page_state(zone, NR_SLAB_RECLAIMABLE); + m = zone_page_state(zone, NR_SLAB_RECLAIMABLE); + if (m < n) + sc.nr_reclaimed += n - m; } p->reclaim_state = NULL; -- 1.6.5.2 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/