Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753965AbZIKHh5 (ORCPT ); Fri, 11 Sep 2009 03:37:57 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1753841AbZIKHhz (ORCPT ); Fri, 11 Sep 2009 03:37:55 -0400 Received: from mx2.mail.elte.hu ([157.181.151.9]:42960 "EHLO mx2.mail.elte.hu" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753286AbZIKHhy (ORCPT ); Fri, 11 Sep 2009 03:37:54 -0400 Date: Fri, 11 Sep 2009 09:37:47 +0200 From: Ingo Molnar To: Jens Axboe , Martin Schwidefsky , John Stultz Cc: 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: <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> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20090910180049.GA10579@elte.hu> User-Agent: Mutt/1.5.18 (2008-05-17) X-ELTE-SpamScore: -1.5 X-ELTE-SpamLevel: X-ELTE-SpamCheck: no X-ELTE-SpamVersion: ELTE 2.0 X-ELTE-SpamCheck-Details: score=-1.5 required=5.9 tests=BAYES_00 autolearn=no SpamAssassin version=3.2.5 -1.5 BAYES_00 BODY: Bayesian spam probability is 0 to 1% [score: 0.0000] Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1686 Lines: 58 * 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? Ingo -- 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/