Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754059AbZIKHsa (ORCPT ); Fri, 11 Sep 2009 03:48:30 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1753462AbZIKHs3 (ORCPT ); Fri, 11 Sep 2009 03:48:29 -0400 Received: from mtagate2.de.ibm.com ([195.212.17.162]:44380 "EHLO mtagate2.de.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753423AbZIKHs2 (ORCPT ); Fri, 11 Sep 2009 03:48:28 -0400 Date: Fri, 11 Sep 2009 09:48:28 +0200 From: Martin Schwidefsky To: Ingo Molnar Cc: Jens Axboe , John Stultz , Peter Zijlstra , Mike Galbraith , Con Kolivas , linux-kernel@vger.kernel.org Subject: Re: [crash, bisected] Re: clocksource: Resolve cpu hotplug dead lock with TSC unstable Message-ID: <20090911094828.024a4098@skybase> In-Reply-To: <20090911073747.GA8209@elte.hu> References: <20090909091009.GR18599@kernel.dk> <20090909115429.GY18599@kernel.dk> <20090909122006.GA18599@kernel.dk> <1252565738.7205.29.camel@laptop> <20090910065856.GL18599@kernel.dk> <20090910073317.GP18599@kernel.dk> <20090910074902.GA10634@elte.hu> <20090910075357.GT18599@kernel.dk> <20090910100214.GB21314@elte.hu> <20090910180049.GA10579@elte.hu> <20090911073747.GA8209@elte.hu> Organization: IBM Corporation X-Mailer: Claws Mail 3.7.2 (GTK+ 2.16.6; i486-pc-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1973 Lines: 68 On Fri, 11 Sep 2009 09:37:47 +0200 Ingo Molnar wrote: > > * Ingo Molnar wrote: > > > > > * Ingo Molnar wrote: > > > > > > > > * Jens Axboe wrote: > > > > > > > I went to try -tip btw, but it crashes on boot. Here's the > > > > backtrace, typed manually, it's crashing in > > > > queue_work_on+0x28/0x60. > > > > > > > > Call Trace: > > > > queue_work > > > > schedule_work > > > > clocksource_mark_unstable > > > > mark_tsc_unstable > > > > check_tsc_sync_source > > > > native_cpu_up > > > > relay_hotcpu_callback > > > > do_forK_idle > > > > _cpu_up > > > > cpu_up > > > > kernel_init > > > > kernel_thread_helper > > > > > > hm, that looks like an old bug i fixed days ago via: > > > > > > 00a3273: Revert "x86: Make tsc=reliable override boot time stability checks" > > > > > > Have you tested tip:master - do you still know which sha1? > > > > Ok, i reproduced it on a testbox and bisected it, the crash is > > caused by: > > > > 7285dd7fd375763bfb8ab1ac9cf3f1206f503c16 is first bad commit > > commit 7285dd7fd375763bfb8ab1ac9cf3f1206f503c16 > > Author: Thomas Gleixner > > Date: Fri Aug 28 20:25:24 2009 +0200 > > > > clocksource: Resolve cpu hotplug dead lock with TSC unstable > > > > Martin Schwidefsky analyzed it: > > > > I've reverted it in tip/master for now. > > and that uncovers the circular locking bug that this commit was > supposed to fix ... > > Martin? Damn, back to running around in circles .. -- blue skies, Martin. "Reality continues to ruin my life." - Calvin. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/