From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([208.118.235.92]:46319) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1TF7NA-0002FY-AO for qemu-devel@nongnu.org; Fri, 21 Sep 2012 13:50:41 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1TF7N9-0008Ut-68 for qemu-devel@nongnu.org; Fri, 21 Sep 2012 13:50:40 -0400 Received: from mx1.redhat.com ([209.132.183.28]:51762) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1TF7N8-0008Up-Tv for qemu-devel@nongnu.org; Fri, 21 Sep 2012 13:50:39 -0400 Date: Fri, 21 Sep 2012 14:50:27 -0300 From: Rafael Aquini Message-ID: <20120921175026.GD6665@optiplex.redhat.com> References: <1348224383-1499-1-git-send-email-mgorman@suse.de> <1348224383-1499-5-git-send-email-mgorman@suse.de> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1348224383-1499-5-git-send-email-mgorman@suse.de> Subject: Re: [Qemu-devel] [PATCH 4/9] mm: compaction: Abort compaction loop if lock is contended or run too long List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Mel Gorman Cc: Richard Davies , KVM , QEMU-devel , LKML , Linux-MM , Avi Kivity , Andrew Morton , Shaohua Li On Fri, Sep 21, 2012 at 11:46:18AM +0100, Mel Gorman wrote: > From: Shaohua Li > > Changelog since V2 > o Fix BUG_ON triggered due to pages left on cc.migratepages > o Make compact_zone_order() require non-NULL arg `contended' > > Changelog since V1 > o only abort the compaction if lock is contended or run too long > o Rearranged the code by Andrea Arcangeli. > > isolate_migratepages_range() might isolate no pages if for example when > zone->lru_lock is contended and running asynchronous compaction. In this > case, we should abort compaction, otherwise, compact_zone will run a > useless loop and make zone->lru_lock is even contended. > > [minchan@kernel.org: Putback pages isolated for migration if aborting] > [akpm@linux-foundation.org: compact_zone_order requires non-NULL arg contended] > Signed-off-by: Andrea Arcangeli > Signed-off-by: Shaohua Li > Signed-off-by: Mel Gorman > Acked-by: Rik van Riel > --- Acked-by: Rafael Aquini