From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1762086AbXGFMol (ORCPT ); Fri, 6 Jul 2007 08:44:41 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1759645AbXGFMof (ORCPT ); Fri, 6 Jul 2007 08:44:35 -0400 Received: from web32606.mail.mud.yahoo.com ([68.142.207.233]:43221 "HELO web32606.mail.mud.yahoo.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with SMTP id S1760232AbXGFMoe (ORCPT ); Fri, 6 Jul 2007 08:44:34 -0400 X-YMail-OSG: 6AxQ.QIVM1l90UpSm1FXu0IWVweRgo70I6UIyuTI.EPxQOdpPFn1QYZcP0I22zMtDOGAqskiskW1ekiSvnt9V3aglw-- X-RocketYMMF: knobi.rm Date: Fri, 6 Jul 2007 05:44:33 -0700 (PDT) From: Martin Knoblauch Reply-To: knobi@knobisoft.de Subject: Re: Understanding I/O behaviour To: linux-kernel@vger.kernel.org MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7BIT Message-ID: <791963.30234.qm@web32606.mail.mud.yahoo.com> Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Brice Figureau wrote: >> CFQ gives less (about 10-15%) throughput except for the kernel >> with the >> cfs cpu scheduler, where CFQ is on par with the other IO >> schedulers. >> > >Please have a look to kernel bug #7372: >http://bugzilla.kernel.org/show_bug.cgi?id=7372 > >It seems I encountered the almost same issue. > >The fix on my side, beside running 2.6.17 (which was working fine >for me) was to: >1) have /proc/sys/vm/vfs_cache_pressure=1 >2) have /proc/sys/vm/dirty_ratio=1 and > /proc/sys/vm/dirty_background_ratio=1 >3) have /proc/sys/vm/swappiness=2 >4) run Peter Zijlstra: per dirty device throttling patch on the > top of 2.6.21.5: >http://www.ussg.iu.edu/hypermail/linux/kernel/0706.1/2776.html Brice, any of them sufficient, or all together nedded? Just to avoid confusion. Cheers Martin ------------------------------------------------------ Martin Knoblauch email: k n o b i AT knobisoft DOT de www: http://www.knobisoft.de