From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758725Ab0JHPpW (ORCPT ); Fri, 8 Oct 2010 11:45:22 -0400 Received: from smtp110.prem.mail.ac4.yahoo.com ([76.13.13.93]:36569 "HELO smtp110.prem.mail.ac4.yahoo.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with SMTP id S1753784Ab0JHPpU (ORCPT ); Fri, 8 Oct 2010 11:45:20 -0400 X-Yahoo-SMTP: _Dag8S.swBC1p4FJKLCXbs8NQzyse1SYSgnAbY0- X-YMail-OSG: IFZjCNEVM1mcMDNbsxU6JI0Xo0rlfxDTrz7tPFPiLV4JMm0 hEtB0v6Ac3msmreC0kjJPitxmZp21etWQf47Obt1dcr.miT2ipqvmTQ4VVcK xketdkPnjGV1m4SwbIFf4Ppy3bNQv.VujNMCESlxY8QpuUUEI7kmd_nIG2fz Y4sKEUWq1xkIF_Nqdmrms5NAEuPv7h8a.4TiqZC0l5uoEBfnFYTb0pj61d4b z X-Yahoo-Newman-Property: ymail-3 Date: Fri, 8 Oct 2010 10:45:16 -0500 (CDT) From: Christoph Lameter X-X-Sender: cl@router.home To: Balbir Singh cc: KOSAKI Motohiro , Mel Gorman , Rob Mueller , linux-kernel@vger.kernel.org, Bron Gondwana , linux-mm , David Rientjes Subject: Re: [resend][PATCH] mm: increase RECLAIM_DISTANCE to 30 In-Reply-To: <20101008090427.GB5327@balbir.in.ibm.com> Message-ID: References: <20101008104852.803E.A69D9226@jp.fujitsu.com> <20101008090427.GB5327@balbir.in.ibm.com> User-Agent: Alpine 2.00 (DEB 1167 2008-08-23) MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, 8 Oct 2010, Balbir Singh wrote: > 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? 10 is the local distance. So 30 should be 3x the latency that a local access takes. > 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? Right.