Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755686AbZINPhV (ORCPT ); Mon, 14 Sep 2009 11:37:21 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752263AbZINPhV (ORCPT ); Mon, 14 Sep 2009 11:37:21 -0400 Received: from mtagate6.de.ibm.com ([195.212.17.166]:40544 "EHLO mtagate6.de.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755061AbZINPhU (ORCPT ); Mon, 14 Sep 2009 11:37:20 -0400 Date: Mon, 14 Sep 2009 17:37:20 +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: <20090914173720.5774c01f@skybase> In-Reply-To: <20090914151958.GA17791@elte.hu> References: <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> <20090911153305.3fe9a361@skybase> <20090914151958.GA17791@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: 952 Lines: 29 On Mon, 14 Sep 2009 17:19:58 +0200 Ingo Molnar wrote: > Now another box crashes during bootup. Reverting these two: > > f79e025: clocksource: Resolve cpu hotplug dead lock with TSC unstable, fix crash > 7285dd7: clocksource: Resolve cpu hotplug dead lock with TSC unstable > > allows me to boot it. > > plain 32-bit defconfig. I've seen the bug report. init_workqueues comes after smp_init. The idea I'm currently playing with is a simple check in the tsc code if the tsc clocksource is already registered or not. When smp_init is called the tsc is not yet registered, we could just set the rating to zero. -- 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/