Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753938Ab0DRVaw (ORCPT ); Sun, 18 Apr 2010 17:30:52 -0400 Received: from cantor.suse.de ([195.135.220.2]:38604 "EHLO mx1.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752121Ab0DRVau (ORCPT ); Sun, 18 Apr 2010 17:30:50 -0400 Subject: Re: [PATCH] mm: disallow direct reclaim page writeback From: James Bottomley To: 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 In-Reply-To: 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> Content-Type: text/plain; charset="UTF-8" Date: Sun, 18 Apr 2010 16:30:36 -0500 Message-ID: <1271626236.27350.70.camel@mulgrave.site> Mime-Version: 1.0 X-Mailer: Evolution 2.28.2 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1232 Lines: 30 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 ... James -- 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/