Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752809AbaJTPTK (ORCPT ); Mon, 20 Oct 2014 11:19:10 -0400 Received: from mx1.redhat.com ([209.132.183.28]:64541 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752141AbaJTPTE (ORCPT ); Mon, 20 Oct 2014 11:19:04 -0400 Message-ID: <544527CE.8090607@redhat.com> Date: Mon, 20 Oct 2014 11:18:38 -0400 From: Rik van Riel User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:24.0) Gecko/20100101 Thunderbird/24.7.0 MIME-Version: 1.0 To: Vlastimil Babka , Andrew Morton CC: linux-mm@kvack.org, linux-kernel@vger.kernel.org, Minchan Kim , Mel Gorman , Joonsoo Kim , Michal Nazarewicz , Naoya Horiguchi , Christoph Lameter , David Rientjes Subject: Re: [PATCH 3/5] mm, compaction: defer only on COMPACT_COMPLETE References: <1412696019-21761-1-git-send-email-vbabka@suse.cz> <1412696019-21761-4-git-send-email-vbabka@suse.cz> In-Reply-To: <1412696019-21761-4-git-send-email-vbabka@suse.cz> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 10/07/2014 11:33 AM, Vlastimil Babka wrote: > Deferred compaction is employed to avoid compacting zone where sync direct > compaction has recently failed. As such, it makes sense to only defer when > a full zone was scanned, which is when compact_zone returns with > COMPACT_COMPLETE. It's less useful to defer when compact_zone returns with > apparent success (COMPACT_PARTIAL), followed by a watermark check failure, > which can happen due to parallel allocation activity. It also does not make > much sense to defer compaction which was completely skipped (COMPACT_SKIP) for > being unsuitable in the first place. > > This patch therefore makes deferred compaction trigger only when > COMPACT_COMPLETE is returned from compact_zone(). Results of stress-highalloc > becnmark show the difference is within measurement error, so the issue is > rather cosmetic. > > Signed-off-by: Vlastimil Babka > Cc: Minchan Kim > Cc: Mel Gorman > Cc: Joonsoo Kim > Cc: Michal Nazarewicz > Cc: Naoya Horiguchi > Cc: Christoph Lameter > Cc: Rik van Riel > Cc: David Rientjes Acked-by: Rik van Riel -- 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/