From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754869AbXEIInp (ORCPT ); Wed, 9 May 2007 04:43:45 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1754342AbXEIIng (ORCPT ); Wed, 9 May 2007 04:43:36 -0400 Received: from smtp1.linux-foundation.org ([65.172.181.25]:51482 "EHLO smtp1.linux-foundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753643AbXEIIne (ORCPT ); Wed, 9 May 2007 04:43:34 -0400 Date: Wed, 9 May 2007 01:43:28 -0700 From: Andrew Morton To: David Miller Cc: efault@gmx.de, linux-kernel@vger.kernel.org Subject: Re: multi-second freezes with current GIT? Message-Id: <20070509014328.35d1d087.akpm@linux-foundation.org> In-Reply-To: <20070508.232326.44096869.davem@davemloft.net> References: <20070508.184458.21594839.davem@davemloft.net> <1178681360.7487.59.camel@Homer.simpson.net> <20070508.232326.44096869.davem@davemloft.net> X-Mailer: Sylpheed 2.4.1 (GTK+ 2.8.17; x86_64-unknown-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Tue, 08 May 2007 23:23:26 -0700 (PDT) David Miller wrote: > From: Mike Galbraith > Date: Wed, 09 May 2007 05:29:20 +0200 > > > On Tue, 2007-05-08 at 18:44 -0700, David Miller wrote: > > > I've been noticing this off and on for the past week or so. > > > > > > The system seems to jam up for several seconds, anything that would > > > need to read from disk just sits there during this time. I think it's > > > correlated with generating a lot of dirty write data. > > > > > > My mouse moves around in X etc. so it really is only processes that > > > need to read from disk that get stuck. > > > > > > Perhaps it's a side effect of those dirty ratio changes Linus made to > > > start off the 2.6.22 merge cycle? > > > > Uhoh, that seems highly likely. > > > > I think those changes may have been triggered by my repeatable and truly > > horrible system stalls when writing to an ext3 data=ordered nearly full > > filesystem. Anything that does fdatasync() and/or fsync() can cause > > very bad experiences indeed. KDE's little menu/program launcher > > doohickey does fdatasync() for some odd reason, which has utterly killed > > my entire GUI for up to and including 20 minutes at a whack. > > > > Switching to data=writeback cured those horrors. Lowering the dirty > > ratio reduced the agony of data=ordered tremendously, but didn't make it > > even remotely acceptable. > > I'm using data=ordered on my partitions too. does echo 40 > /proc/sys/vm/dirty_ratio echo 10 > /proc/sys/vm/dirty_background_ratio fix it?