From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753850Ab3ARRol (ORCPT ); Fri, 18 Jan 2013 12:44:41 -0500 Received: from e35.co.us.ibm.com ([32.97.110.153]:40191 "EHLO e35.co.us.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751424Ab3ARRok (ORCPT ); Fri, 18 Jan 2013 12:44:40 -0500 Date: Fri, 18 Jan 2013 09:35:16 -0800 From: "Paul E. McKenney" To: Ben Hutchings Cc: Steven Rostedt , linux-kernel@vger.kernel.org Subject: Re: INFO: rcu_bh detected stall on CPU 3 (t=0 jiffies) Message-ID: <20130118173516.GL3159@linux.vnet.ibm.com> Reply-To: paulmck@linux.vnet.ibm.com References: <20130102190920.GD29452@charite.de> <20130102205630.GA5594@home.goodmis.org> <20130102212948.GA25701@linux.vnet.ibm.com> <1357174163.10284.8.camel@gandalf.local.home> <1358050431.4514.57.camel@deadeye.wl.decadent.org.uk> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1358050431.4514.57.camel@deadeye.wl.decadent.org.uk> User-Agent: Mutt/1.5.21 (2010-09-15) X-Content-Scanned: Fidelis XPS MAILER x-cbid: 13011817-4834-0000-0000-000002BC2A68 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Sun, Jan 13, 2013 at 04:13:51AM +0000, Ben Hutchings wrote: > On Wed, 2013-01-02 at 19:49 -0500, Steven Rostedt wrote: > > On Wed, 2013-01-02 at 13:29 -0800, Paul E. McKenney wrote: > > > On Wed, Jan 02, 2013 at 03:56:30PM -0500, Steven Rostedt wrote: > > > > On Wed, Jan 02, 2013 at 08:09:20PM +0100, Ralf Hildebrandt wrote: > > > > > This happened of a virtual guest (Linux mail 3.2.0-35-virtual #55-Ubuntu SMP Wed Dec 5 18:02:05 UTC 2012 x86_64 x86_64 x86_64 GNU/Linux) > > > > > > > > 3.2 is rather old and this looks to be a stock Ubuntu kernel. May want > > > > to file a Bugzilla (or whatever they call it) with them. > > > > > > > > > > > > > > Jan 2 13:24:08 mail kernel: [3531872.484283] INFO: rcu_bh detected stall on CPU 3 (t=0 jiffies) > > > > > > > > 0 jiffies? > > > > > > One possibility is that they are missing commit a10d206e (rcu: Fix > > > day-one dyntick-idle stall-warning bug), at least assuming that > > > CONFIG_PREEMPT=n. This went into 3.6, IIRC. > > > > If that does fix the issue, we probably should send that off to Ben for > > inclusion into 3.2 stable. > > If I read the Ubuntu changelog correctly, Ralf's machine is running a > version based on 3.2.34, which already has this change (I applied it in > 3.2.32). OK, another possibility is c8020a67. Ralf, if that does not help, is it possible for you to run either a 3.7 or a -rcu kernel [*]? There are some other fixes that could be related, but the probability seems low. Thanx, Paul [*] git://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-rcu.git branch rcu/next