Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755653Ab0FYLXd (ORCPT ); Fri, 25 Jun 2010 07:23:33 -0400 Received: from fgwmail6.fujitsu.co.jp ([192.51.44.36]:46717 "EHLO fgwmail6.fujitsu.co.jp" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754525Ab0FYLXc (ORCPT ); Fri, 25 Jun 2010 07:23:32 -0400 X-SecurityPolicyCheck-FJ: OK by FujitsuOutboundMailChecker v1.3.1 From: KOSAKI Motohiro To: LKML , linux-mm , Andrew Morton , Christoph Lameter , Mel Gorman , Rik van Riel , Minchan Kim , Johannes Weiner Subject: [PATCH 2/2] vmscan: don't subtraction of unsined Cc: kosaki.motohiro@jp.fujitsu.com In-Reply-To: <20100625201915.8067.A69D9226@jp.fujitsu.com> References: <20100625201915.8067.A69D9226@jp.fujitsu.com> Message-Id: <20100625202126.806A.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: Fri, 25 Jun 2010 20:23:29 +0900 (JST) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2057 Lines: 61 'slab_reclaimable' and 'nr_pages' are unsigned. so, subtraction is unsafe. Cc: Christoph Lameter Cc: Rik van Riel Signed-off-by: KOSAKI Motohiro --- mm/vmscan.c | 18 ++++++++++++------ 1 files changed, 12 insertions(+), 6 deletions(-) diff --git a/mm/vmscan.c b/mm/vmscan.c index c927948..b1a90f8 100644 --- a/mm/vmscan.c +++ b/mm/vmscan.c @@ -2612,6 +2612,8 @@ static int __zone_reclaim(struct zone *zone, gfp_t gfp_mask, unsigned int order) slab_reclaimable = zone_page_state(zone, NR_SLAB_RECLAIMABLE); if (slab_reclaimable > zone->min_slab_pages) { unsigned long lru_pages = zone_reclaimable_pages(zone); + unsigned long srec_new; + /* * shrink_slab() does not currently allow us to determine how * many pages were freed in this zone. So we take the current @@ -2622,17 +2624,21 @@ static int __zone_reclaim(struct zone *zone, gfp_t gfp_mask, unsigned int order) * Note that shrink_slab will free memory on all zones and may * take a long time. */ - while (shrink_slab(sc.nr_scanned, gfp_mask, lru_pages) && - zone_page_state(zone, NR_SLAB_RECLAIMABLE) > - slab_reclaimable - nr_pages) - ; + for (;;) { + if (!shrink_slab(sc.nr_scanned, gfp_mask, lru_pages)) + break; + srec_new = zone_page_state(zone, NR_SLAB_RECLAIMABLE); + if (srec_new + nr_pages <= slab_reclaimable) + break; + } /* * 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); + srec_new = zone_page_state(zone, NR_SLAB_RECLAIMABLE); + if (srec_new < slab_reclaimable) + sc.nr_reclaimed += slab_reclaimable - srec_new; } 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/