From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751492Ab0DSEbX (ORCPT ); Mon, 19 Apr 2010 00:31:23 -0400 Received: from casper.infradead.org ([85.118.1.10]:53434 "EHLO casper.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750742Ab0DSEbV (ORCPT ); Mon, 19 Apr 2010 00:31:21 -0400 Date: Sun, 18 Apr 2010 21:32:38 -0700 From: Arjan van de Ven To: Dave Chinner Cc: Andrew Morton , Mel Gorman , KOSAKI Motohiro , Chris Mason , linux-kernel@vger.kernel.org, linux-mm@kvack.org, linux-fsdevel@vger.kernel.org Subject: Re: [PATCH] mm: disallow direct reclaim page writeback Message-ID: <20100418213238.2e62eac7@infradead.org> In-Reply-To: <20100419010805.GD2520@dastard> References: <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> <20100419003556.GC2520@dastard> <20100418174944.7b9716ad@infradead.org> <20100419010805.GD2520@dastard> Organization: Intel X-Mailer: Claws Mail 3.7.5 (GTK+ 2.16.6; i586-redhat-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit X-SRS-Rewrite: SMTP reverse-path rewritten from by casper.infradead.org See http://www.infradead.org/rpr.html Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, 19 Apr 2010 11:08:05 +1000 Dave Chinner wrote: > > Maybe we need to do the background dirty writes a bit more > > aggressive... or play with heuristics where we get an adaptive > > timeout (say, if the file got closed by the last opener, then do a > > shorter timeout) > > Realistically, I'm concerned about preventing the worst case > behaviour from occurring - making the background writes more > agressive without preventing writeback in LRU order simply means it > will be harder to test the VM corner case that triggers these > writeout patterns... while I appreciate that the worst case should not be uber horrific... I care a LOT about getting the normal case right... and am willing to sacrifice the worst case for that.. (obviously not to infinity, it needs to be bounded) -- Arjan van de Ven Intel Open Source Technology Centre For development, discussion and tips for power savings, visit http://www.lesswatts.org