From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932355AbVHaEbu (ORCPT ); Wed, 31 Aug 2005 00:31:50 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S932353AbVHaEbt (ORCPT ); Wed, 31 Aug 2005 00:31:49 -0400 Received: from dial169-151.awalnet.net ([213.184.169.151]:55303 "EHLO raad.intranet") by vger.kernel.org with ESMTP id S932343AbVHaEbt (ORCPT ); Wed, 31 Aug 2005 00:31:49 -0400 From: Al Boldi To: Holger Kiehl Subject: Re: Where is the performance bottleneck? Date: Wed, 31 Aug 2005 07:30:38 -0300 User-Agent: KMail/1.5 Cc: linux-kernel , linux-raid References: <200508292310.39903.a1426z@gawab.com> In-Reply-To: MIME-Version: 1.0 Content-Disposition: inline Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit Message-Id: <200508310730.38112.a1426z@gawab.com> Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Holger Kiehl wrote: > On Mon, 29 Aug 2005, Al Boldi wrote: > > You may be hitting a 2.6 kernel bug, which has something to do with > > readahead, ask Jens Axboe about it! (see "[git patches] IDE update" > > thread) Sadly, 2.6.13 did not fix it either. > > I did read that threat, but due to my limited understanding about kernel > code, don't see the relation to my problem. Basically the kernel is loosing CPU cycles while accessing bockdevices. The problem shows most when the CPU/DISK ratio is low. Throwing more CPU cycles at the problem may seemingly remove this bottleneck. > But I am willing to try any patches to solve the problem. No patches yet. > > Did you try 2.4.31? > > No. Will give this a try if the problem is not found. Keep us posted! -- Al