From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail138.messagelabs.com (mail138.messagelabs.com [216.82.249.35]) by kanga.kvack.org (Postfix) with SMTP id 7E5916B004D for ; Wed, 17 Feb 2010 23:09:53 -0500 (EST) Message-ID: <4B7CBD71.2040709@redhat.com> Date: Wed, 17 Feb 2010 23:09:21 -0500 From: Rik van Riel MIME-Version: 1.0 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: owner-linux-mm@kvack.org 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 List-ID: 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, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org