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 B47FD6B009B for ; Mon, 11 Oct 2010 21:55:55 -0400 (EDT) Received: from m3.gw.fujitsu.co.jp ([10.0.50.73]) by fgwmail6.fujitsu.co.jp (Fujitsu Gateway) with ESMTP id o9C1trR0027772 for (envelope-from kosaki.motohiro@jp.fujitsu.com); Tue, 12 Oct 2010 10:55:53 +0900 Received: from smail (m3 [127.0.0.1]) by outgoing.m3.gw.fujitsu.co.jp (Postfix) with ESMTP id ED55E45DE4E for ; Tue, 12 Oct 2010 10:55:52 +0900 (JST) Received: from s3.gw.fujitsu.co.jp (s3.gw.fujitsu.co.jp [10.0.50.93]) by m3.gw.fujitsu.co.jp (Postfix) with ESMTP id C29D445DE4F for ; Tue, 12 Oct 2010 10:55:52 +0900 (JST) Received: from s3.gw.fujitsu.co.jp (localhost.localdomain [127.0.0.1]) by s3.gw.fujitsu.co.jp (Postfix) with ESMTP id AABA91DB8041 for ; Tue, 12 Oct 2010 10:55:52 +0900 (JST) Received: from m107.s.css.fujitsu.com (m107.s.css.fujitsu.com [10.249.87.107]) by s3.gw.fujitsu.co.jp (Postfix) with ESMTP id 611561DB803B for ; Tue, 12 Oct 2010 10:55:52 +0900 (JST) From: KOSAKI Motohiro Subject: Re: [resend][PATCH] mm: increase RECLAIM_DISTANCE to 30 In-Reply-To: <20101008090427.GB5327@balbir.in.ibm.com> References: <20101008104852.803E.A69D9226@jp.fujitsu.com> <20101008090427.GB5327@balbir.in.ibm.com> Message-Id: <20101012104701.AD2B.A69D9226@jp.fujitsu.com> MIME-Version: 1.0 Content-Type: text/plain; charset="US-ASCII" Content-Transfer-Encoding: 7bit Date: Tue, 12 Oct 2010 10:55:51 +0900 (JST) Sender: owner-linux-mm@kvack.org To: balbir@linux.vnet.ibm.com Cc: kosaki.motohiro@jp.fujitsu.com, Christoph Lameter , Mel Gorman , Rob Mueller , linux-kernel@vger.kernel.org, Bron Gondwana , linux-mm , David Rientjes List-ID: Hi > > -#define RECLAIM_DISTANCE 20 > > +#define RECLAIM_DISTANCE 30 > > #endif > > #ifndef PENALTY_FOR_NODE_WITH_CPUS > > #define PENALTY_FOR_NODE_WITH_CPUS (1) > > I am not sure if this makes sense, since RECLAIM_DISTANCE is supposed > to be a hardware parameter. Could you please help clarify what the > access latency of a node with RECLAIM_DISTANCE 20 to that of a node > with RECLAIM_DISTANCE 30 is? Has the hardware definition of reclaim > distance changed? Recently, Intel/AMD implemented QPI/Hypertransport on their cpus. Then, commodity server's average node distance dramatically changed and our threshold became typical case unfit. So, my intention is, commodity server continue to don't use zone_reclaim_mode. because their workload haven't been changed. 30 itself don't have strong meaning. > I suspect the side effect is the zone_reclaim_mode is not set to 1 on > bootup for the 2-4 socket machines you mention, which results in > better VM behaviour? It depend on workload. If you are using file/web/emal server (i.e. most common case), it's better. but HPC workload don't works so fine. -- 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