From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S266679AbUGLBA3 (ORCPT ); Sun, 11 Jul 2004 21:00:29 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S266680AbUGLBA2 (ORCPT ); Sun, 11 Jul 2004 21:00:28 -0400 Received: from smtp808.mail.ukl.yahoo.com ([217.12.12.198]:12176 "HELO smtp808.mail.ukl.yahoo.com") by vger.kernel.org with SMTP id S266679AbUGLBA0 (ORCPT ); Sun, 11 Jul 2004 21:00:26 -0400 From: Alistair John Strachan Reply-To: s0348365@sms.ed.ac.uk Organization: University of Edinburgh To: sboyce@blueyonder.co.uk Subject: Re: 2.6.x Scheduler, preemption and responsiveness - puzzlement Date: Mon, 12 Jul 2004 02:00:32 +0100 User-Agent: KMail/1.6.82 Cc: bert hubert , linux-kernel@vger.kernel.org References: <40F1BA46.9000207@blueyonder.co.uk> <20040711221818.GA30704@outpost.ds9a.nl> <40F1C568.2070503@blueyonder.co.uk> In-Reply-To: <40F1C568.2070503@blueyonder.co.uk> MIME-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit Content-Disposition: inline Message-Id: <200407120200.32938.s0348365@sms.ed.ac.uk> Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Sunday 11 July 2004 23:55, Sid Boyce wrote: [snip] > > I've been wondering why this is, I can't remember what the BIOS says > about the hard drives, from memory it looked OK, I think it was set to > AUTO, haven't tried LBA. > # hdparm -d1 /dev/hda > > /dev/hda: > setting using_dma to 1 (on) > HDIO_SET_DMA failed: Operation not permitted > using_dma = 0 (off) > # hdparm -d1 /dev/hdc > > /dev/hdc: > setting using_dma to 1 (on) > HDIO_SET_DMA failed: Operation not permitted > using_dma = 0 (off) > Your BIOS geometry settings are irrelevant. You've just forgotten to enable the correct busmaster DMA driver in your kernel. It looks as though this is an nForce 2 system, so you need to enable "Generic PCI bus-master DMA support", then further down "AMD and nVidia IDE support", in menuconfig. You'll then be able to set DMA on, and this will likely resolve the performance issue. In .config, the relevant options are CONFIG_BLK_DEV_IDEDMA_PCI=y CONFIG_BLK_DEV_AMD74XX=y Hope this helps! -- Cheers, Alistair. personal: alistair()devzero!co!uk university: s0348365()sms!ed!ac!uk student: CS/AI Undergraduate contact: 1F2 55 South Clerk Street, Edinburgh. EH8 9PP.