Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753169Ab0BREKl (ORCPT ); Wed, 17 Feb 2010 23:10:41 -0500 Received: from mx1.redhat.com ([209.132.183.28]:55435 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751804Ab0BREKj (ORCPT ); Wed, 17 Feb 2010 23:10:39 -0500 Message-ID: <4B7CBD71.2040709@redhat.com> Date: Wed, 17 Feb 2010 23:09:21 -0500 From: Rik van Riel Organization: Red Hat, Inc User-Agent: Mozilla/5.0 (X11; U; Linux x86_64; en-US; rv:1.9.1.5) Gecko/20091209 Fedora/3.0-4.fc12 Lightning/1.0pre Thunderbird/3.0 MIME-Version: 1.0 To: Mel Gorman CC: Andrea Arcangeli , Christoph Lameter , Adam Litke , Avi Kivity , David Rientjes , KOSAKI Motohiro , linux-kernel@vger.kernel.org, linux-mm@kvack.org Subject: Re: [PATCH 09/12] Do not compact within a preferred zone after a compaction failure References: <1265976059-7459-1-git-send-email-mel@csn.ul.ie> <1265976059-7459-10-git-send-email-mel@csn.ul.ie> In-Reply-To: <1265976059-7459-10-git-send-email-mel@csn.ul.ie> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1064 Lines: 25 On 02/12/2010 07:00 AM, Mel Gorman wrote: > The fragmentation index may indicate that a failure it due to external > fragmentation, a compaction run complete and an allocation failure still > fail. There are two obvious reasons as to why > > o Page migration cannot move all pages so fragmentation remains > o A suitable page may exist but watermarks are not met > > In the event of compaction and allocation failure, this patch prevents > compaction happening for a short interval. It's only recorded on the > preferred zone but that should be enough coverage. This could have been > implemented similar to the zonelist_cache but the increased size of the > zonelist did not appear to be justified. > > Signed-off-by: Mel Gorman Acked-by: Rik van Riel -- All rights reversed. -- 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/