From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S936035AbYEBSxi (ORCPT ); Fri, 2 May 2008 14:53:38 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S932154AbYEBSx3 (ORCPT ); Fri, 2 May 2008 14:53:29 -0400 Received: from cpsmtpo-eml01.kpnxchange.com ([213.75.38.150]:41591 "EHLO cpsmtpo-eml01.kpnxchange.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1761947AbYEBSx3 (ORCPT ); Fri, 2 May 2008 14:53:29 -0400 From: Frans Pop To: Mike Galbraith Subject: Re: Horrendous Audio Stutter - current git Date: Fri, 2 May 2008 20:53:23 +0200 User-Agent: KMail/1.9.9 Cc: Parag Warudkar , Peter Zijlstra , Ingo Molnar , LKML References: <82e4877d0805011714m35a47753q58cca706b7af6557@mail.gmail.com> <1209740523.4776.1.camel@marge.simson.net> <200805021749.10205.elendil@planet.nl> In-Reply-To: <200805021749.10205.elendil@planet.nl> MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Content-Disposition: inline Message-Id: <200805022053.24779.elendil@planet.nl> X-OriginalArrivalTime: 02 May 2008 18:53:27.0860 (UTC) FILETIME=[CEB42740:01C8AC85] Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Friday 02 May 2008, Frans Pop wrote: > As I had group scheduling disabled, I only saw the first one. But my > audio skips were a lot less severe than Parag described. And disabling > group scheduling helped solve the problem for him. > > So it may well still be worth following up on this. I have just tested a kernel with GROUP_SCHED enabled (with Peter's patch still included) and can confirm that enabling group scheduling causes serious latencies. Skips are much more frequent than with the issue that was just solved. latencytop shows (different samples) Scheduler: waiting for cpu 537.7 msec Scheduler: waiting for cpu 172.0 msec Scheduler: waiting for cpu 414.6 msec Scheduler: waiting for cpu 455.7 msec Scheduler: waiting for cpu 446.5 msec I think I also see why.... # grep bonus_max `grep -l amarokapp /proc/*/task/*/sched` /proc/4725/task/20645/sched:se.bonus_max : 122640.203776 /proc/4725/task/4725/sched:se.bonus_max : 122640.203776 /proc/4725/task/4793/sched:se.bonus_max : 41902109.884416 /proc/4725/task/4797/sched:se.bonus_max : 41902109.884416 /proc/4725/task/4798/sched:se.bonus_max : 41902109.884416 /proc/4725/task/4799/sched:se.bonus_max : 40880.046080 /proc/4725/task/4800/sched:se.bonus_max : 19.970683