Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753554Ab0DRXd4 (ORCPT ); Sun, 18 Apr 2010 19:33:56 -0400 Received: from mexforward.lss.emc.com ([128.222.32.20]:59258 "EHLO mexforward.lss.emc.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752731Ab0DRXdz (ORCPT ); Sun, 18 Apr 2010 19:33:55 -0400 Date: Sun, 18 Apr 2010 19:34:09 -0400 To: "James Bottomley" Subject: Re: [PATCH] mm: disallow direct reclaim page writeback From: "Sorin Faibish" Cc: "Andrew Morton" , "Mel Gorman" , "Dave Chinner" , "KOSAKI Motohiro" , "Chris Mason" , linux-kernel@vger.kernel.org, linux-mm@kvack.org, linux-fsdevel@vger.kernel.org Content-Type: text/plain; format=flowed; delsp=yes; charset=iso-8859-15 MIME-Version: 1.0 References: <20100413202021.GZ13327@think> <20100414014041.GD2493@dastard> <20100414155233.D153.A69D9226@jp.fujitsu.com> <20100414072830.GK2493@dastard> <20100414085132.GJ25756@csn.ul.ie> <20100415013436.GO2493@dastard> <20100415102837.GB10966@csn.ul.ie> <20100416041412.GY2493@dastard> <20100416151403.GM19264@csn.ul.ie> <20100417203239.dda79e88.akpm@linux-foundation.org> <1271626236.27350.70.camel@mulgrave.site> Content-Transfer-Encoding: 8bit Message-ID: In-Reply-To: <1271626236.27350.70.camel@mulgrave.site> User-Agent: Opera Mail/9.63 (Win32) X-EMM-EM: Active Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2050 Lines: 63 On Sun, 18 Apr 2010 17:30:36 -0400, James Bottomley wrote: > On Sun, 2010-04-18 at 15:10 -0400, Sorin Faibish wrote: >> On Sat, 17 Apr 2010 20:32:39 -0400, Andrew Morton >> wrote: >> >> > >> > There are two issues here: stack utilisation and poor IO patterns in >> > direct reclaim. They are different. >> > >> > The poor IO patterns thing is a regression. Some time several years >> > ago (around 2.6.16, perhaps), page reclaim started to do a LOT more >> > dirty-page writeback than it used to. AFAIK nobody attempted to work >> > out why, nor attempted to try to fix it. > >> I for one am looking very seriously at this problem together with Bruce. >> We plan to have a discussion on this topic at the next LSF meeting >> in Boston. > > As luck would have it, the Memory Management summit is co-located with > the Storage and Filesystem workshop ... how about just planning to lock > all the protagonists in a room if it's not solved by August. The less > extreme might even like to propose topics for the plenary sessions ... Let's work together to get this done. This is a very good idea. I will try to bring some facts about the current state by instrumenting the kernel to sample with higher time granularity the dirty pages dynamics. This will allow us expose better the problem or lack of. :) /Sorin > > James > > > -- > To unsubscribe from this list: send the line "unsubscribe linux-fsdevel" > in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html > > -- Best Regards Sorin Faibish Corporate Distinguished Engineer Network Storage Group EMC? where information lives Phone: 508-435-1000 x 48545 Cellphone: 617-510-0422 Email : sfaibish@emc.com -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/