From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S262509AbTHUIF2 (ORCPT ); Thu, 21 Aug 2003 04:05:28 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S262512AbTHUIF2 (ORCPT ); Thu, 21 Aug 2003 04:05:28 -0400 Received: from ns.suse.de ([195.135.220.2]:25741 "EHLO Cantor.suse.de") by vger.kernel.org with ESMTP id S262509AbTHUIFW (ORCPT ); Thu, 21 Aug 2003 04:05:22 -0400 Message-ID: <3F447D40.5020000@suse.de> Date: Thu, 21 Aug 2003 10:05:20 +0200 From: Hannes Reinecke Organization: SuSE Linux AG User-Agent: Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.4) Gecko/20030624 X-Accept-Language: en-us, en MIME-Version: 1.0 To: Dave Hansen Cc: Linux Kernel Mailing List Subject: Re: Dumb question: BKL on reboot ? References: <3F434BD1.9050704@suse.de> <20030820112918.0f7ce4fe.akpm@osdl.org> <20030820113520.281fe8bb.davem@redhat.com> <1061411024.9371.33.camel@nighthawk> In-Reply-To: <1061411024.9371.33.camel@nighthawk> X-Enigmail-Version: 0.76.5.0 X-Enigmail-Supports: pgp-inline, pgp-mime Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Dave Hansen wrote: [ .. ] > > Or, are you saying that a CPU could have the BKL, and have > stop_this_cpu() called on it? I guess we could add > release_kernel_lock() to stop_this_cpu(). Exactly what happened here. CPU#1 entered sys_reboot, got BKL and prepared to stop. It will never release BKL, leaving a nice big window for CPU#0 to deadlock. releasing BKL before calling do_machine_restart seems to do the trick, though. Cheers, Hannes -- Dr. Hannes Reinecke hare@suse.de SuSE Linux AG S390 & zSeries Deutschherrnstr. 15-19 +49 911 74053 688 90429 Nürnberg http://www.suse.de