From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755809AbZBIPTV (ORCPT ); Mon, 9 Feb 2009 10:19:21 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1754633AbZBIPTH (ORCPT ); Mon, 9 Feb 2009 10:19:07 -0500 Received: from qmta09.emeryville.ca.mail.comcast.net ([76.96.30.96]:51517 "EHLO QMTA09.emeryville.ca.mail.comcast.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754620AbZBIPTF (ORCPT ); Mon, 9 Feb 2009 10:19:05 -0500 Message-ID: <49904988.50408@xyzw.org> Date: Mon, 09 Feb 2009 07:19:36 -0800 From: Brian Rogers User-Agent: Thunderbird 2.0.0.19 (X11/20090103) MIME-Version: 1.0 To: Greg KH CC: Mike Galbraith , Peter Zijlstra , Linux Kernel Mailing List , Jan Engelhardt , Ingo Molnar , Nathanael Hoyle , stable Subject: Re: [stable] scheduler nice 19 versus 'idle' behavior / static low-priority scheduling References: <1233294584.28741.2.camel@localhost> <1233297635.17301.11.camel@localhost> <1233302349.17301.27.camel@localhost> <1233302861.6061.14.camel@marge.simson.net> <49837B32.3010206@xyzw.org> <1233380284.5636.5.camel@marge.simson.net> <1233392893.5863.25.camel@marge.simson.net> <20090202235714.GE32075@kroah.com> In-Reply-To: <20090202235714.GE32075@kroah.com> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Greg KH wrote: > On Sat, Jan 31, 2009 at 10:08:13AM +0100, Mike Galbraith wrote: > >> On Sat, 2009-01-31 at 06:38 +0100, Mike Galbraith wrote: >> >>> On Fri, 2009-01-30 at 14:12 -0800, Brian Rogers wrote: >>> >>>> Mike Galbraith wrote: >>>> >>>>> On Fri, 2009-01-30 at 02:59 -0500, Nathanael Hoyle wrote: >>>>> >>>>> >>>>>> I am running foldingathome under it at the moment, and it seems to be >>>>>> improving the situation somewhat, but I still need/want to test with >>>>>> Mike's referenced patches. >>>>>> >>>>>> >>>>> You will most definitely encounter evilness running SCHED_IDLE tasks in >>>>> a kernel without the SCHED_IDLE fixes. >>>>> >>>>> >>>> Speaking of SCHED_IDLE fixes, is >>>> 6bc912b71b6f33b041cfde93ca3f019cbaa852bc going to be put into the next >>>> stable 2.6.28 release? Without it on 2.6.28.2, I can still produce >>>> minutes-long freezes with BOINC or other idle processes. >>>> >>>> With the above commit on top of 2.6.28.2 and also >>>> cce7ade803699463ecc62a065ca522004f7ccb3d, the problem is solved, though >>>> I assume cce7ad isn't actually required to fix that, and I can test that >>>> if desired. >>>> >>> I think they both should go to stable, but dunno if they're headed that >>> direction or not. >>> >>> One way to find out, CCs added. >>> >> For those who may want to run SCHED_IDLE tasks in .27, I've integrated >> and lightly tested the fixes required to do so. One additional commit >> was needed to get SCHED_IDLE vs nice 19 working right, namely f9c0b09. >> Without that, SCHED_IDLE tasks received more CPU than nice 19 tasks. >> >> Since .27 is in long-term maintenance, I'd integrate into stable, but >> that's not my decision. Anyone who applies the below to their stable >> kernel gets to keep all the pieces should something break ;-) >> > > I'm going to hold off and not do this, as it seems too risky. > > But thanks for the pointers, perhaps someone else will want to do this > for their distro kernels if they have problems with this. > Is this statement meant to apply to both 2.6.27 and 2.6.28, or just 2.6.27?