From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751085Ab3ELSTs (ORCPT ); Sun, 12 May 2013 14:19:48 -0400 Received: from canardo.mork.no ([148.122.252.1]:42199 "EHLO canardo.mork.no" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750808Ab3ELSTr convert rfc822-to-8bit (ORCPT ); Sun, 12 May 2013 14:19:47 -0400 From: =?utf-8?Q?Bj=C3=B8rn_Mork?= To: paulmck@linux.vnet.ibm.com Cc: Dipankar Sarma , linux-kernel@vger.kernel.org, rostedt@goodmis.org Subject: Re: [v3.10-rc1] WARNING: at kernel/rcutree.c:502 Organization: m References: <87ip2opntp.fsf@nemi.mork.no> <20130512113905.GH3648@linux.vnet.ibm.com> <87li7kp50r.fsf@nemi.mork.no> <20130512172135.GJ3648@linux.vnet.ibm.com> Date: Sun, 12 May 2013 20:19:34 +0200 In-Reply-To: <20130512172135.GJ3648@linux.vnet.ibm.com> (Paul E. McKenney's message of "Sun, 12 May 2013 10:21:35 -0700") Message-ID: <87a9o0ukll.fsf@nemi.mork.no> User-Agent: Gnus/5.11002 (No Gnus v0.20) Emacs/23.4 (gnu/linux) MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 8BIT Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org "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. Bjørn