From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S261659AbVFKJav (ORCPT ); Sat, 11 Jun 2005 05:30:51 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S261660AbVFKJaV (ORCPT ); Sat, 11 Jun 2005 05:30:21 -0400 Received: from smtp.osdl.org ([65.172.181.4]:50916 "EHLO smtp.osdl.org") by vger.kernel.org with ESMTP id S261659AbVFKJaK (ORCPT ); Sat, 11 Jun 2005 05:30:10 -0400 Date: Sat, 11 Jun 2005 02:29:59 -0700 From: Andrew Morton To: spaminos-ker@yahoo.com Cc: linux-kernel@vger.kernel.org Subject: Re: cfq misbehaving on 2.6.11-1.14_FC3 Message-Id: <20050611022959.3954ff6b.akpm@osdl.org> In-Reply-To: <20050610225443.75162.qmail@web30704.mail.mud.yahoo.com> References: <20050610225443.75162.qmail@web30704.mail.mud.yahoo.com> X-Mailer: Sylpheed version 1.0.4 (GTK+ 1.2.10; i386-redhat-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 wrote: > > Hello, I am running into a very bad problem on one of my production servers. > > * the config > Linux Fedora core 3 latest everything, kernel 2.6.11-1.14_FC3 > AMD Opteron 2 GHz, 1 G RAM, 80 GB Hard drive (IDE, Western Digital) > > I have a log processor running in the background, it's using sqlite for storing > the information it finds in the logs. It takes a few hours to complete a run. > It's clearly I/O bound (SleepAVG = 98%, according to /proc/pid/status). > I have to use the cfq scheduler because it's the only scheduler that is fair > between processes (or should be, keep reading). > > * the problem > Now, after an hour or so of processing, the machine becomes very unresponsive > when trying to do new disk operations. I say new because existing processes > that stream data to disk don't seem to suffer so much. It might be useful to test 2.6.12-rc6-mm1 - it has a substantially rewritten CFQ implementation.