From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754512AbYILJNd (ORCPT ); Fri, 12 Sep 2008 05:13:33 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752477AbYILJNX (ORCPT ); Fri, 12 Sep 2008 05:13:23 -0400 Received: from mx2.mail.elte.hu ([157.181.151.9]:36304 "EHLO mx2.mail.elte.hu" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751852AbYILJNW (ORCPT ); Fri, 12 Sep 2008 05:13:22 -0400 Date: Fri, 12 Sep 2008 11:13:08 +0200 From: Ingo Molnar To: Andrew Morton Cc: linux-kernel@vger.kernel.org, Thomas Gleixner , bugme-daemon@bugzilla.kernel.org, j_kernel@hoblitt.com Subject: Re: [Bugme-new] [Bug 11543] New: kernel panic: softlockup in tick_periodic() ??? Message-ID: <20080912091308.GA10305@elte.hu> References: <20080911170258.aa0bea0d.akpm@linux-foundation.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20080911170258.aa0bea0d.akpm@linux-foundation.org> User-Agent: Mutt/1.5.18 (2008-05-17) X-ELTE-VirusStatus: clean 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=3.2.3 -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 * Andrew Morton wrote: > I can't work out who called panic(), nor why. > > The panic code called the kexec code which called mutex_trylock() > which called spin_lock_mutex() which then stupidly went and blurted a > load of debug stuff because of in_interrupt(). agreed - applied your fix in the form below to tip/master - thanks Andrew. J, you might want to try tip/master, it includes all known fixes for this area and this debug improvement as well. You can pick it up via: http://people.redhat.com/mingo/tip.git/README Ingo ----------> >>From 53b9d87f41a3d8838210ad7cdef02d814817ce85 Mon Sep 17 00:00:00 2001 From: Andrew Morton Date: Thu, 11 Sep 2008 17:02:58 -0700 Subject: [PATCH] lock debug: sit tight when we are already in a panic in: > http://bugzilla.kernel.org/show_bug.cgi?id=11543 The panic code called the kexec code which called mutex_trylock() which called spin_lock_mutex() which then stupidly went and blurted a load of debug stuff because of in_interrupt(). Keep the lock debug code from escallating an already crappy situation. Signed-off-by: Ingo Molnar --- include/linux/debug_locks.h | 2 +- 1 files changed, 1 insertions(+), 1 deletions(-) diff --git a/include/linux/debug_locks.h b/include/linux/debug_locks.h index 4aaa4af..096476f 100644 --- a/include/linux/debug_locks.h +++ b/include/linux/debug_locks.h @@ -17,7 +17,7 @@ extern int debug_locks_off(void); ({ \ int __ret = 0; \ \ - if (unlikely(c)) { \ + if (!oops_in_progress && unlikely(c)) { \ if (debug_locks_off() && !debug_locks_silent) \ WARN_ON(1); \ __ret = 1; \