From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752134Ab3ELU6r (ORCPT ); Sun, 12 May 2013 16:58:47 -0400 Received: from e8.ny.us.ibm.com ([32.97.182.138]:45611 "EHLO e8.ny.us.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751607Ab3ELU6q (ORCPT ); Sun, 12 May 2013 16:58:46 -0400 Date: Sun, 12 May 2013 13:58:24 -0700 From: "Paul E. McKenney" To: =?iso-8859-1?Q?Bj=F8rn?= Mork Cc: Dipankar Sarma , linux-kernel@vger.kernel.org, rostedt@goodmis.org Subject: Re: [v3.10-rc1] WARNING: at kernel/rcutree.c:502 Message-ID: <20130512205824.GL3648@linux.vnet.ibm.com> Reply-To: paulmck@linux.vnet.ibm.com References: <87ip2opntp.fsf@nemi.mork.no> <20130512113905.GH3648@linux.vnet.ibm.com> <87li7kp50r.fsf@nemi.mork.no> <20130512172135.GJ3648@linux.vnet.ibm.com> <87a9o0ukll.fsf@nemi.mork.no> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <87a9o0ukll.fsf@nemi.mork.no> User-Agent: Mutt/1.5.21 (2010-09-15) X-TM-AS-MML: No X-Content-Scanned: Fidelis XPS MAILER x-cbid: 13051220-9360-0000-0000-0000122337C2 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Sun, May 12, 2013 at 08:19:34PM +0200, Bjørn Mork wrote: > "Paul E. McKenney" writes: > > On Sun, May 12, 2013 at 05:55:00PM +0200, Bjørn Mork wrote: > >> "Paul E. McKenney" writes: > >> > On Sun, May 12, 2013 at 11:08:50AM +0200, Bjørn Mork wrote: > >> >> Hello, > >> >> > >> >> got the splat below when running powertop on plain v3.10-rc1 > >> >> (i.e. without my previously mentioned revert patch or any other extra > >> >> patches). Config attached. > >> > > >> > OK, it looks like you have context-tracking enabled, so you might be > >> > hitting a bug that Steven Rostedt found a few days ago. Could you > >> > please try out his fix below? > >> > >> Thanks for the quick reply, but I'm afraid that patch had no effect on > >> the warning I got. It's still there. > > > > Other than wondering whether powertop has issues similar to the bug > > Steven Rostedt located, I must confess myself clueless. Here are some > > diagnostics I can suggest: > > > > 1. Run in 32-bit mode. This disables some of the new adaptive-ticks > > functionality, so might give a probabilistic indication of where > > the bug lies. > > > > 2. The standard fallback of bisection. > > > > Would you be willing to do either of these? > > Willing, yes. But it will take some time before I am able to do either > unless I can recreate the problem in a virtual machine. I assume that > you by " 32-bit mode" mean a 32bit kernel? I'm not exactly set up to > run that on my laptop. Bisection will be less work. > > To be honest, I don't even know how old this thing is. It could be > totally unrelated to your recent changes for all I know. Running > powertop is something I do once every 6 kernel releases or something > like that... > > I'll see what I can come up with. Thanks for your attention. And thank you for the testing and information! Thanx, Paul