From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S263540AbTJVL0i (ORCPT ); Wed, 22 Oct 2003 07:26:38 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S263541AbTJVL0i (ORCPT ); Wed, 22 Oct 2003 07:26:38 -0400 Received: from mailout07.sul.t-online.com ([194.25.134.83]:56456 "EHLO mailout07.sul.t-online.com") by vger.kernel.org with ESMTP id S263540AbTJVL0g (ORCPT ); Wed, 22 Oct 2003 07:26:36 -0400 Message-ID: <3F9669BF.1040408@t-online.de> Date: Wed, 22 Oct 2003 13:27:59 +0200 From: Knut Petersen User-Agent: Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.4.1) Gecko/20031011 X-Accept-Language: en-us, en MIME-Version: 1.0 To: James Courtier-Dutton CC: "'linux-kernel@vger.kernel.org'" Subject: Re: VIA IDE performance under 2.6.0-test7/8? References: <3F957DAC.6080901@superbug.demon.co.uk> In-Reply-To: <3F957DAC.6080901@superbug.demon.co.uk> X-Enigmail-Version: 0.76.7.0 X-Enigmail-Supports: pgp-inline, pgp-mime Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit X-Seen: false X-ID: GtMRm8ZEQeOK5xPFgRN24jTy8CuyWkcb06pqJ4fevhHRD+b8udgXwM@t-dialin.net Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Hi James! > Can you also send the output from "cat /proc/interrupts". > It looks like you are not using IO-APIC, but instead using XT-PIC. > XT-PIC is a lot slower than IO-APIC. Reading the previous messages I compared the SuSE 2.4.20-4GB and the 2.6.0-test8-bk1 kernel. The mainboard is a VIA EPIA 5000 (cpu Via Eden 533 Mhz, Via 8601A Northbridge, VT8231 Southbridge) hdparm -I /dev/hd? displays no difference ... udma2 is the used mode. hdparm -T /dev/hd? measures transfer rates of 60-63 MB/s, there is no significant difference between the kernel versions. hdparm -t /dev/hd? mesasures 18 MB/s for kernel 2.6.0-test8-bk1 and 27 MB/s for kernel 2.4.20. This is a significant :-( 2.4.20 gives almost exactly 50% better performance compared to 2.6.0-test8 ... is this pure accident or could this give a hint? > Just turn on SMB support in the "make menuconf", and it should enable > IO-APIC. Compiling the kernel with and without smb support as well as trying the other APIC related new configuration options does change nothing. There is allways a "No local APIC present or hardware disabled" message. I believe that there really is no IO-APIC, at least I found no related BIOS configuration option. /proc/interrupts indicates an XT-PIC for both kernel versions. IRQ setup is identical, IDE IRQs are not shared with any other devices. The drive is the only drive attached. Playing around with different read-ahead values does not help. Any ideas? cu, Knut Petersen