From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756929AbYEQSlq (ORCPT ); Sat, 17 May 2008 14:41:46 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752005AbYEQSli (ORCPT ); Sat, 17 May 2008 14:41:38 -0400 Received: from smtp1.linux-foundation.org ([140.211.169.13]:51022 "EHLO smtp1.linux-foundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751937AbYEQSlh (ORCPT ); Sat, 17 May 2008 14:41:37 -0400 Date: Sat, 17 May 2008 11:41:20 -0700 (PDT) From: Linus Torvalds To: Alistair John Strachan cc: Jens Axboe , xfs@oss.sgi.com, Neil Brown , Nick Piggin , linux-kernel@vger.kernel.org Subject: Re: XFS/md/blkdev warning (was Re: Linux 2.6.26-rc2) In-Reply-To: Message-ID: References: <20080512164920.GE16217@kernel.dk> <200805171922.56272.alistair@devzero.co.uk> User-Agent: Alpine 1.10 (LFD 962 2008-03-14) MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Sat, 17 May 2008, Linus Torvalds wrote: > > Do this on the console (and having a serial console or working netconsole > is a wonderful thing to log it, because otherwise it will generally just > scroll off the screen), and trigger SysRQ-w. That dumps all blocked tasks > to the screen. Another thing to try is to enable lock debugging, and have CONFIG_DEBUG_SPINLOCK=y CONFIG_DEBUG_MUTEXES=y CONFIG_DEBUG_LOCK_ALLOC=y CONFIG_PROVE_LOCKING=y CONFIG_LOCKDEP=y CONFIG_DEBUG_LOCKDEP=y in your kernel .config file. It has performance implications, of course, but it can help debug incorrect locking much more quickly. Linus