From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S267204AbUBNAJQ (ORCPT ); Fri, 13 Feb 2004 19:09:16 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S267233AbUBNAJQ (ORCPT ); Fri, 13 Feb 2004 19:09:16 -0500 Received: from kinesis.swishmail.com ([209.10.110.86]:54030 "EHLO kinesis.swishmail.com") by vger.kernel.org with ESMTP id S267204AbUBNAJO (ORCPT ); Fri, 13 Feb 2004 19:09:14 -0500 Message-ID: <402D68CB.2030803@techsource.com> Date: Fri, 13 Feb 2004 19:16:11 -0500 From: Timothy Miller MIME-Version: 1.0 To: Timothy Miller CC: Linux Kernel Mailing List , Balaji Calidas Subject: IDE DMA problem [WAS: Re: Getting lousy NFS + tar-pipe throughput on 2.4.20] References: <402D6262.90301@techsource.com> In-Reply-To: <402D6262.90301@techsource.com> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org I have discovered one major problem that I didn't think to check before. I have never before had trouble using DMA with WD drives, VIA chipsets, or RH9, so I didn't think to check before, but hdparm reports that DMA is disabled for the disk on the workstation I mentioned in my earlier post. So, I tried this: hdparm -d1 /dev/hda And I got this result: /dev/hda: Setting using_dma to 1 (on) HDIO_SET_DMA failed: Operation not permitted using_dma = 0 (off) How do I fix this? Do I have to unmount the filesystem before I can change the dma setting? Why would it be off to begin with? I know that the BIOS is set up right. Does 2.4.20 not work well with the KT600 chipset? Thanks. Timothy Miller wrote: > [snip everything about slow NFS performance]