From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756309Ab0IUOOT (ORCPT ); Tue, 21 Sep 2010 10:14:19 -0400 Received: from smtp110.prem.mail.ac4.yahoo.com ([76.13.13.93]:45553 "HELO smtp110.prem.mail.ac4.yahoo.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with SMTP id S1753521Ab0IUOOQ (ORCPT ); Tue, 21 Sep 2010 10:14:16 -0400 X-Yahoo-SMTP: _Dag8S.swBC1p4FJKLCXbs8NQzyse1SYSgnAbY0- X-YMail-OSG: FfQNcV0VM1lrhVD6UZ.Yqthmz.Et1vaH1nvCdO.1tdL.LYr cLmPlre8Ci8EPD_.z4FF7.yDq1o.eSpb7v7K.JwbDbbWJQSiJ3SCnC_BvFgh Vo.F.N2sRL9LOy5lG84jyMGdiImN8Dsch4yQ5bpXTCbCvAPklw3w430oDr5H h0vDkiQZd_PACWOB6wmVtxeHJFbJvx22.pJAyfnnVbZi2A8aL1eiPfuOmM7n 3chpZ70xCdNf6iYSHHGQF.crjRn1g X-Yahoo-Newman-Property: ymail-3 Date: Tue, 21 Sep 2010 09:14:13 -0500 (CDT) From: Christoph Lameter X-X-Sender: cl@router.home To: Mel Gorman cc: Rob Mueller , KOSAKI Motohiro , linux-kernel@vger.kernel.org, Bron Gondwana , linux-mm Subject: Re: Default zone_reclaim_mode = 1 on NUMA kernel is bad forfile/email/web servers In-Reply-To: <20100921090407.GA11439@csn.ul.ie> Message-ID: References: <1284349152.15254.1394658481@webmail.messagingengine.com> <20100916184240.3BC9.A69D9226@jp.fujitsu.com> <20100920093440.GD1998@csn.ul.ie> <52C8765522A740A4A5C027E8FDFFDFE3@jem> <20100921090407.GA11439@csn.ul.ie> 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 Tue, 21 Sep 2010, Mel Gorman wrote: > > However there's still another question, why is this problem happening at > > all for us? I know almost nothing about NUMA, but from other posts, it > > sounds like the problem is the memory allocations are all happening on > > one node? > > Yes. This could be a screwy hardware issue as pointed out before. Certain controllers restrict the memory that I/O can be done to also (32 bit controller only able to do I/O to lower 2G?, controller on a PCI bus that is local only to a particular node) which would make balancing the file cache difficult. From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail143.messagelabs.com (mail143.messagelabs.com [216.82.254.35]) by kanga.kvack.org (Postfix) with SMTP id 319796B004A for ; Tue, 21 Sep 2010 10:14:17 -0400 (EDT) Date: Tue, 21 Sep 2010 09:14:13 -0500 (CDT) From: Christoph Lameter Subject: Re: Default zone_reclaim_mode = 1 on NUMA kernel is bad forfile/email/web servers In-Reply-To: <20100921090407.GA11439@csn.ul.ie> Message-ID: References: <1284349152.15254.1394658481@webmail.messagingengine.com> <20100916184240.3BC9.A69D9226@jp.fujitsu.com> <20100920093440.GD1998@csn.ul.ie> <52C8765522A740A4A5C027E8FDFFDFE3@jem> <20100921090407.GA11439@csn.ul.ie> MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: owner-linux-mm@kvack.org To: Mel Gorman Cc: Rob Mueller , KOSAKI Motohiro , linux-kernel@vger.kernel.org, Bron Gondwana , linux-mm List-ID: On Tue, 21 Sep 2010, Mel Gorman wrote: > > However there's still another question, why is this problem happening at > > all for us? I know almost nothing about NUMA, but from other posts, it > > sounds like the problem is the memory allocations are all happening on > > one node? > > Yes. This could be a screwy hardware issue as pointed out before. Certain controllers restrict the memory that I/O can be done to also (32 bit controller only able to do I/O to lower 2G?, controller on a PCI bus that is local only to a particular node) which would make balancing the file cache difficult. -- 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