From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S265203AbTLaSEw (ORCPT ); Wed, 31 Dec 2003 13:04:52 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S265217AbTLaSEw (ORCPT ); Wed, 31 Dec 2003 13:04:52 -0500 Received: from rat-3.inet.it ([213.92.5.93]:31923 "EHLO rat-3.inet.it") by vger.kernel.org with ESMTP id S265203AbTLaSEu (ORCPT ); Wed, 31 Dec 2003 13:04:50 -0500 From: Paolo Ornati To: Ed Sweetman Subject: Re: 2.6.1-rc1 [resend] Date: Wed, 31 Dec 2003 19:03:56 +0100 User-Agent: KMail/1.5.2 Cc: William Lee Irwin III , linux-kernel@vger.kernel.org References: <200312311645.23348.ornati@lycos.it> <3FF2F9FE.2000403@wmich.edu> In-Reply-To: <3FF2F9FE.2000403@wmich.edu> MIME-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit Content-Disposition: inline Message-Id: <200312311903.56832.ornati@lycos.it> Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Wednesday 31 December 2003 17:31, Ed Sweetman wrote: > Paolo Ornati wrote: > > On Wednesday 31 December 2003 16:20, you wrote: > >>On Wednesday 31 December 2003 16:06, you wrote: > >>>>What io scheduler are you using? Or, could you post /var/log/dmesg? > >> > >>On Wed, Dec 31, 2003 at 04:19:27PM +0100, Paolo Ornati wrote: > >>>"dmesg" and "config" attached. > >> > >>Could you try this with elevator=deadline? > > > > ok, I have just tried... > > I don't see any big difference. > > Wasn't it mentioned in another thread related to a drop in ide > performance that there is possibly some bug in the ide code that ends up > requiring you to set the readahead on all your devices to see the max > performance of any one? > > set all the readaheads of all your ide devices to 8192 You should see > the best peformance doing this. No, I have just try it but I don't see any changes. My question is about a strange change of "behaviour" in IDE performance changing readahead. Here I report a new thing that I've noticed today: Kernel 2.6.0: o readahead up to 224: when I run "hdparm -t /dev/hda" the HD LED light up... and after a while light down o readahead > 224: running "hdparm" the HD LED starts blinking... and then light down The best performance are riched with values between 128 and 224 --> IOW when the HD led starts blinking the performance diminish... Kernel 2.6.1-rc1: the HD LED starts to blink with readahead = 16 !!! Why? BYE -- Paolo Ornati Linux v2.6.0