From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753129Ab1AUSUN (ORCPT ); Fri, 21 Jan 2011 13:20:13 -0500 Received: from mail-ew0-f46.google.com ([209.85.215.46]:52518 "EHLO mail-ew0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752082Ab1AUSUM (ORCPT ); Fri, 21 Jan 2011 13:20:12 -0500 DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=message-id:date:subject:from:to:mime-version; b=KTn0c+tLw3roFbqE19ElwaiEU9n3Nid4oAx7U0T18Pk85YkEbjHpXlNJ4L8cLkKSeA t9kaiJABVjBSai5NbI6qByToqg/Sq1xRW+6biagBfsjYN9O/RGHf6udjCO7LyWVfjafQ UZqQED8DCuINiWPACbIjFIcpzdYtNjjcxw5eU= Message-ID: <4d39ce58.cc7e0e0a.5448.59e4@mx.google.com> Date: Fri, 21 Jan 2011 10:20:08 -0800 (PST) Subject: 'autogroup' sched code KILLING responsiveness From: Michael Witten To: linux-kernel@vger.kernel.org MIME-version: 1.0 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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). I'm using a uniprocessor (UP) machine, and I've noticed that such codepaths often get clobbered by changes that only make it to SMP configurations (I guess kernel hackers have better equipment than I do); maybe that has something to do with it. I'm a laymen, so all I can do at this time is report my experience; if this has already been discussed, I would appeciate a link to the right thread. Sincerely, Michael Witten