From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753276AbZBJFYu (ORCPT ); Tue, 10 Feb 2009 00:24:50 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751109AbZBJFYm (ORCPT ); Tue, 10 Feb 2009 00:24:42 -0500 Received: from smtp1.linux-foundation.org ([140.211.169.13]:53450 "EHLO smtp1.linux-foundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750841AbZBJFYl (ORCPT ); Tue, 10 Feb 2009 00:24:41 -0500 Date: Mon, 9 Feb 2009 21:23:56 -0800 (PST) From: Linus Torvalds X-X-Sender: torvalds@localhost.localdomain To: Mathieu Desnoyers cc: KOSAKI Motohiro , Jens Axboe , akpm@linux-foundation.org, Peter Zijlstra , Ingo Molnar , thomas.pi@arcor.dea, Yuriy Lalym , ltt-dev@lists.casi.polymtl.ca, linux-kernel@vger.kernel.org, linux-mm@kvack.org Subject: Re: [PATCH] mm fix page writeback accounting to fix oom condition under heavy I/O In-Reply-To: <20090210033652.GA28435@Krystal> Message-ID: References: <20090120122855.GF30821@kernel.dk> <20090120232748.GA10605@Krystal> <20090123220009.34DF.KOSAKI.MOTOHIRO@jp.fujitsu.com> <20090210033652.GA28435@Krystal> User-Agent: Alpine 2.00 (LFD 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 Mon, 9 Feb 2009, Mathieu Desnoyers wrote: > > So this patch fixes this behavior by only decrementing the page accounting > _after_ the block I/O writepage has been done. This makes no sense, really. Or rather, I don't mind the notion of updating the counters only after IO per se, and _that_ part of it probably makes sense. But why is it that you only then fix up two of the call-sites. There's a lot more call-sites than that for this function. So if this really makes a big difference, that's an interesting starting point for discussion, but I don't see how this particular patch could possibly be the right thing to do. Linus