From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755009Ab1FEH5u (ORCPT ); Sun, 5 Jun 2011 03:57:50 -0400 Received: from mailout-de.gmx.net ([213.165.64.23]:42808 "HELO mailout-de.gmx.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with SMTP id S1754696Ab1FEH5t (ORCPT ); Sun, 5 Jun 2011 03:57:49 -0400 X-Authenticated: #14349625 X-Provags-ID: V01U2FsdGVkX1/Dcip0oZ7DUk7CindL1sD3GpMmBNp9ZwfFXI332N LGDhfZSWFndIzG Subject: Re: [tip:sched/locking] sched: Add p->pi_lock to task_rq_lock() From: Mike Galbraith To: Arne Jansen Cc: Peter Zijlstra , Linus Torvalds , Ingo Molnar , hpa@zytor.com, linux-kernel@vger.kernel.org, npiggin@kernel.dk, akpm@linux-foundation.org, frank.rowand@am.sony.com, linux-tip-commits@vger.kernel.org, Thomas Gleixner In-Reply-To: <4DEB1BD6.6070405@die-jansens.de> References: <20110405152729.232781355@chello.nl> <4DE64596.5010006@die-jansens.de> <1306946120.2497.606.camel@laptop> <4DE674EB.1000200@die-jansens.de> <1306951751.2497.626.camel@laptop> <1306953870.2497.627.camel@laptop> <4DE6936F.7090700@die-jansens.de> <1307092535.2353.2973.camel@twins> <4DE8B13D.9020302@die-jansens.de> <4DE8DC28.30709@die-jansens.de> <1307225323.2497.730.camel@laptop> <4DEB1BD6.6070405@die-jansens.de> Content-Type: text/plain; charset="UTF-8" Date: Sun, 05 Jun 2011 09:57:40 +0200 Message-ID: <1307260660.9019.17.camel@marge.simson.net> Mime-Version: 1.0 X-Mailer: Evolution 2.32.1 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 Sun, 2011-06-05 at 08:01 +0200, Arne Jansen wrote: > On 05.06.2011 00:08, Peter Zijlstra wrote: > > On Sun, 2011-06-05 at 06:29 +0900, Linus Torvalds wrote: > >> On Fri, Jun 3, 2011 at 10:05 PM, Arne Jansen wrote: > >>> > >>> No change. Also git bisect quite clearly points to > >>> 0122ec5b02f766c and ab2515c4b98f7bc4, both are older than > >>> b1c43f82c5aa2654 mentioned in the other thread. > >> > >> Ok, I haven't heard anything further on this. Ingo? Peter? > > > > I'm a bit stumped, and not being able to reproduce at all :/ > > I'm willing to take any number of round trips to get to the true > nature of the bug. From the description I have a feeling that the > offending patch might just shift the timing slightly, so even if > the problem is gone for me, it might just be buried deeper. > I can also try to reproduce it on a second machine and give you > access to it, though this might take a few days. My x3550 M3 with your config plus a couple drivers I need is exhibiting hard lockups with no watchdog triggered. If I use both serial and tty consoles, I get all kinds of gripes from soft lockup and rcu when loading Peter's test module, but that's the tty problem. With serial console and earlyprintk=serial alone, box may or may not boot all the way without hard locking silently. Ditto on restart after loading/unloading Peter's test module. I always see all 10k messages though, IFF I have no tty console active. -Mike