From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S261861AbTHTKWM (ORCPT ); Wed, 20 Aug 2003 06:22:12 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S261862AbTHTKWM (ORCPT ); Wed, 20 Aug 2003 06:22:12 -0400 Received: from ns.suse.de ([195.135.220.2]:56799 "EHLO Cantor.suse.de") by vger.kernel.org with ESMTP id S261861AbTHTKWL (ORCPT ); Wed, 20 Aug 2003 06:22:11 -0400 Message-ID: <3F434BD1.9050704@suse.de> Date: Wed, 20 Aug 2003 12:22:09 +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: Linux Kernel Subject: Dumb question: BKL on reboot ? X-Enigmail-Version: 0.76.5.0 X-Enigmail-Supports: pgp-inline, pgp-mime Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Hiya, I've got a dumb question: Why is the BKL held on entering sys_reboot() in kernel/sys.c:405 ? It is getting especially interesting on SMP, when one cpu is entering sys_reboot, acquires the BKL and then waits (via machine_restart) for all other cpus to shut down. If any of the other cpus is executing a task which also needs the BKL, we have a nice deadlock. We've seen this here on 2-way s390, where the other cpu tried to execute kupdated() (what did it try that for? Anyway...), which of course resulted in a deadlock. Any enlightenment welcome. Cheers, Hannes P.S.: Please cc me directly, I'm not subscribed. -- Dr. Hannes Reinecke hare@suse.de SuSE Linux AG S390 & zSeries Deutschherrnstr. 15-19 +49 911 74053 688 90429 Nürnberg http://www.suse.de