From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail191.messagelabs.com (mail191.messagelabs.com [216.82.242.19]) by kanga.kvack.org (Postfix) with SMTP id A4C346B004D for ; Wed, 17 Feb 2010 22:58:18 -0500 (EST) Message-ID: <4B7CBAB4.2010003@redhat.com> Date: Wed, 17 Feb 2010 22:57:40 -0500 From: Rik van Riel MIME-Version: 1.0 Subject: Re: [PATCH 08/12] Direct compact when a high-order allocation fails References: <1265976059-7459-1-git-send-email-mel@csn.ul.ie> <1265976059-7459-9-git-send-email-mel@csn.ul.ie> In-Reply-To: <1265976059-7459-9-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: > Ordinarily when a high-order allocation fails, direct reclaim is entered to > free pages to satisfy the allocation. With this patch, it is determined if > an allocation failed due to external fragmentation instead of low memory > and if so, the calling process will compact until a suitable page is > freed. Compaction by moving pages in memory is considerably cheaper than > paging out to disk and works where there are locked pages or no swap. If > compaction fails to free a page of a suitable size, then reclaim will > still occur. > > Direct compaction returns as soon as possible. As each block is compacted, > it is checked if a suitable page has been freed and if so, it returns. > > 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