Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id ; Thu, 20 Dec 2001 12:40:55 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id ; Thu, 20 Dec 2001 12:40:45 -0500 Received: from holomorphy.com ([216.36.33.161]:38538 "EHLO holomorphy") by vger.kernel.org with ESMTP id ; Thu, 20 Dec 2001 12:40:33 -0500 Date: Thu, 20 Dec 2001 09:40:25 -0800 From: William Lee Irwin III To: Linux Kernel List Subject: Re: Poor performance during disk writes Message-ID: <20011220094025.B2632@holomorphy.com> Mail-Followup-To: William Lee Irwin III , Linux Kernel List In-Reply-To: <20011220132729Z286241-18285+3296@vger.kernel.org> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Description: brief message Content-Disposition: inline User-Agent: Mutt/1.3.17i In-Reply-To: <20011220132729Z286241-18285+3296@vger.kernel.org>; from Dieter.Nuetzel@hamburg.de on Thu, Dec 20, 2001 at 02:27:17PM +0100 Organization: The Domain of Holomorphy Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Dec 20, 2001 at 02:27:17PM +0100, Dieter N?tzel wrote: > Amen.. > Sorry, Helge sure you are right in theory but try dbench 32 (maybe > bonnie/bonnie++) and playing an MP3/Ogg-Vorbis in parallel... > That's my first test on any "new" kernel version. > > Even with an 1 GHz Athlon II, 640 MB, U160 DDYS 18 GB, 10k IBM disk (on an > AHA-2940UW) it stutters like mad. I am running all my kernel _with_ Robert > Love's preempt + lock-break patches and it doesn't solve the problem. > CPU load is (very) low but it do not work like it should. I tried this on my 600MHz Athlon with 768MB of RAM and U160 DDYS 36GB 10Krpm IBM disk on a Adaptect 39160 I managed to get it not to stutter at all. I was also using preempt + lockbreak and a few others. The crucial patch appeared to be from Andrew Morton and it involved tuning the elevator to avoid read starvation. A significantly helpful hardware suggestion regarding the sound card and drivers came from Linus himself, though. Linus and others pointed out that applications are able to cause some drivers to generate a large number of interrupts by using small buffers and unfriendly ioctl's, especially esd. My workaround was to change out sound hardware and disable esd. If this is happening to you, /proc/profile should show handle_IRQ_event() and schedule() very high up. On the other hand, this shows up as a steady drain on system resources and excessive system time, not stuttering or skipping. Andrew, I don't have the URL for that still floating around. Can you point Dieter to it? Cheers, Bill - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/