From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758193Ab0JHQ7j (ORCPT ); Fri, 8 Oct 2010 12:59:39 -0400 Received: from e8.ny.us.ibm.com ([32.97.182.138]:33976 "EHLO e8.ny.us.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754080Ab0JHQ7i (ORCPT ); Fri, 8 Oct 2010 12:59:38 -0400 Date: Fri, 8 Oct 2010 22:29:30 +0530 From: Balbir Singh To: Christoph Lameter 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 Message-ID: <20101008165930.GH5327@balbir.in.ibm.com> Reply-To: balbir@linux.vnet.ibm.com References: <20101008104852.803E.A69D9226@jp.fujitsu.com> <20101008090427.GB5327@balbir.in.ibm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org * Christoph Lameter [2010-10-08 10:45:16]: > 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. > Does this patch then imply that we should do zone_reclaim only for 3x nodes and not 2x nodes as we did earlier. > > 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. > -- Three Cheers, Balbir