From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S263763AbTLTB0i (ORCPT ); Fri, 19 Dec 2003 20:26:38 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S263767AbTLTB0i (ORCPT ); Fri, 19 Dec 2003 20:26:38 -0500 Received: from mail-09.iinet.net.au ([203.59.3.41]:64192 "HELO mail.iinet.net.au") by vger.kernel.org with SMTP id S263763AbTLTB0e (ORCPT ); Fri, 19 Dec 2003 20:26:34 -0500 Message-ID: <3FE3A53F.6090203@cyberone.com.au> Date: Sat, 20 Dec 2003 12:26:23 +1100 From: Nick Piggin User-Agent: Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.4) Gecko/20030827 Debian/1.4-3 X-Accept-Language: en MIME-Version: 1.0 To: Christian Meder CC: William Lee Irwin III , linux-kernel@vger.kernel.org Subject: Re: 2.6 vs 2.4 regression when running gnomemeeting References: <1071864709.1044.172.camel@localhost> <20031219203227.GR31393@holomorphy.com> <1071876632.1044.179.camel@localhost> <3FE39603.9000501@cyberone.com.au> <1071880660.1044.194.camel@localhost> <3FE39C7A.7050507@cyberone.com.au> <1071882705.1044.207.camel@localhost> In-Reply-To: <1071882705.1044.207.camel@localhost> Content-Type: text/plain; charset=us-ascii; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Christian Meder wrote: >On Sat, 2003-12-20 at 01:48, Nick Piggin wrote: > >>Sounds reasonable. Maybe its large interrupt or scheduling latency >>caused somewhere else. Does disk activity alone cause a problem? >>find / -type f | xargs cat > /dev/null >>how about >>dd if=/dev/zero of=./deleteme bs=1M count=256 >> > >Ok. I've attached the logs from a run with a call with only an >additional dd. The quality was almost undisturbed only very slightly >worse than the unloaded case. > OK, its probably not that then. Try the find command though, it would be closer to what make/gcc is doing. > >>You said it faired slightly better with my scheduler when renicing >>gnome meeting to -10. How much better is that? >> > >Worse than unloaded and worse than the disk loaded case from above. But >all (CPU) loaded cases were producing almost complete audio dropouts >while with your scheduler and renicing to -10 I got at least a >stuttering audio stream (a regular pattern of very short slices of audio >mixed with very short slices of silence). > So it does sound like scheduling latency then. Its difficult to find out what is happening with top and vmstat because they don't give you an idea of individual scheduling events, which is what is important for things like this. I'll have a look into making up a patch to gather what I want to know. In the meantime, I have a newer scheduler patch against 2.6.0 you could try: http://www.kerneltrap.org/~npiggin/v28p1.gz Try nicing the compile to +19 if it still stutters.