From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755089Ab1AVDWi (ORCPT ); Fri, 21 Jan 2011 22:22:38 -0500 Received: from mailout-de.gmx.net ([213.165.64.22]:40167 "HELO mailout-de.gmx.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with SMTP id S1754652Ab1AVDWh (ORCPT ); Fri, 21 Jan 2011 22:22:37 -0500 X-Authenticated: #14349625 X-Provags-ID: V01U2FsdGVkX18y3wRZ1kMyZ7cVuwnAslNbRSVC3fTUSY1mzkX4DL fqVyQMZNcQc8e6 Subject: Re: 'autogroup' sched code KILLING responsiveness From: Mike Galbraith To: Michael Witten Cc: linux-kernel@vger.kernel.org In-Reply-To: References: <4d39ce58.cc7e0e0a.5448.59e4@mx.google.com> <1295648870.23779.15.camel@marge.simson.net> Content-Type: text/plain; charset="UTF-8" Date: Sat, 22 Jan 2011 04:22:34 +0100 Message-ID: <1295666554.8265.2.camel@marge.simson.net> Mime-Version: 1.0 X-Mailer: Evolution 2.30.1.2 Content-Transfer-Encoding: 7bit X-Y-GMX-Trusted: 0 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, 2011-01-21 at 16:39 -0600, Michael Witten wrote: > On Fri, Jan 21, 2011 at 16:27, Mike Galbraith wrote: > > On Fri, 2011-01-21 at 10:20 -0800, Michael Witten wrote: > >> Bisecting shows that this commit: > >> > >> 5091faa449ee0b7d73bc296a93bca9540fc51d0a > >> sched: Add 'autogroup' scheduling feature: automated per session task groups > >> Date: Tue Nov 30 14:18:03 2010 +0100 > >> > >> is the reason that my computer has become unusable. > >> > >> With that code in place, a resource-intensive activity (such as > >> compiling the Linux kernel) causes my computer to become > >> unresponsive for many seconds at a time; the entire screen > >> does not refresh, typed keys are dropped or are handled very > >> late, etc (even in Linux's plain virtual consoles). > > > > That's not what I'm experiencing with a UP kernel... > > Before I try to gather any data, I'd like to point out that the > problem disappears when I disable CONFIG_SCHED_AUTOGROUP (General > setup -> Automatic process group scheduling). > > Do you have it disabled? No, ff I did, mplayer wouldn't be able to get more than 1% cpu. top - 22:34:38 up 33 min, 22 users, load average: 104.07, 101.73, 78.13 Tasks: 675 total, 101 running, 574 sleeping, 0 stopped, 0 zombie Cpu(s): 95.2%us, 4.8%sy, 0.0%ni, 0.0%id, 0.0%wa, 0.0%hi, 0.0%si, 0.0%st PID USER PR NI VIRT RES SHR S %CPU %MEM TIME+ P COMMAND 6770 root 20 0 401m 79m 29m R 46.9 1.0 3:22.66 0 mplayer 6100 root 20 0 449m 94m 18m S 2.9 1.2 1:33.82 0 Xorg 7486 root 20 0 374m 46m 17m S 2.9 0.6 0:54.02 0 konsole -Mike