From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail202.messagelabs.com (mail202.messagelabs.com [216.82.254.227]) by kanga.kvack.org (Postfix) with SMTP id 4FD8A6B01F2 for ; Mon, 16 Aug 2010 10:51:16 -0400 (EDT) Message-ID: <4C695046.9000703@redhat.com> Date: Mon, 16 Aug 2010 10:50:46 -0400 From: Rik van Riel MIME-Version: 1.0 Subject: Re: [PATCH 3/3] mm: page allocator: Drain per-cpu lists after direct reclaim allocation fails References: <1281951733-29466-1-git-send-email-mel@csn.ul.ie> <1281951733-29466-4-git-send-email-mel@csn.ul.ie> In-Reply-To: <1281951733-29466-4-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: linux-mm@kvack.org, Nick Piggin , Johannes Weiner , KAMEZAWA Hiroyuki , KOSAKI Motohiro List-ID: On 08/16/2010 05:42 AM, Mel Gorman wrote: > When under significant memory pressure, a process enters direct reclaim > and immediately afterwards tries to allocate a page. If it fails and no > further progress is made, it's possible the system will go OOM. However, > on systems with large amounts of memory, it's possible that a significant > number of pages are on per-cpu lists and inaccessible to the calling > process. This leads to a process entering direct reclaim more often than > it should increasing the pressure on the system and compounding the problem. > > This patch notes that if direct reclaim is making progress but > allocations are still failing that the system is already under heavy > pressure. In this case, it drains the per-cpu lists and tries the > allocation a second time before continuing. > > Signed-off-by: Mel Gorman Reviewed-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