From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail203.messagelabs.com (mail203.messagelabs.com [216.82.254.243]) by kanga.kvack.org (Postfix) with SMTP id F244B6B005A for ; Thu, 14 May 2009 16:23:03 -0400 (EDT) Message-ID: <4A0C7DB6.6010601@redhat.com> Date: Thu, 14 May 2009 16:23:18 -0400 From: Rik van Riel MIME-Version: 1.0 Subject: Re: [PATCH 4/4] zone_reclaim_mode is always 0 by default References: <20090513120155.5879.A69D9226@jp.fujitsu.com> <20090513120729.5885.A69D9226@jp.fujitsu.com> <20090513152256.GM7601@sgi.com> In-Reply-To: Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org To: Christoph Lameter Cc: Robin Holt , KOSAKI Motohiro , LKML , linux-mm , Andrew Morton List-ID: Christoph Lameter wrote: > Not having zone reclaim on a NUMA system often means that per node > allocations will fall back. Optimized node local allocations become very > difficult for the page allocator. If the latency penalties are not > significant then this may not matter. The larger the system, the larger > the NUMA latencies become. > > One possibility would be to disable zone reclaim for low node numbers. > Eanble it only if more than 4 nodes exist? I suspect that patches 1/4 through 3/4 will cause the system to behave better already, by only reclaiming the easiest to reclaim pages from zone reclaim and falling back after that - or am overlooking something? -- 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