From owner-freebsd-stable@FreeBSD.ORG  Mon Jan 12 10:38:08 2009
Return-Path: <owner-freebsd-stable@FreeBSD.ORG>
Delivered-To: freebsd-stable@FreeBSD.org
Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34])
	by hub.freebsd.org (Postfix) with ESMTP id CD4DE106566B
	for <freebsd-stable@FreeBSD.org>; Mon, 12 Jan 2009 10:38:08 +0000 (UTC)
	(envelope-from gavin@FreeBSD.org)
Received: from mail-gw0.york.ac.uk (mail-gw0.york.ac.uk [144.32.128.245])
	by mx1.freebsd.org (Postfix) with ESMTP id 62E7E8FC08
	for <freebsd-stable@FreeBSD.org>; Mon, 12 Jan 2009 10:38:07 +0000 (UTC)
	(envelope-from gavin@FreeBSD.org)
Received: from mail-gw6.york.ac.uk (mail-gw6.york.ac.uk [144.32.129.26])
	by mail-gw0.york.ac.uk (8.13.6/8.13.6) with ESMTP id n0CAc54w015215;
	Mon, 12 Jan 2009 10:38:05 GMT
Received: from buffy-128.york.ac.uk ([144.32.128.160] helo=buffy.york.ac.uk)
	by mail-gw6.york.ac.uk with esmtps (TLSv1:AES256-SHA:256) (Exim 4.68)
	(envelope-from <gavin@FreeBSD.org>)
	id 1LMKBJ-0000KL-D2; Mon, 12 Jan 2009 10:38:05 +0000
Received: from buffy.york.ac.uk (localhost [127.0.0.1])
	by buffy.york.ac.uk (8.14.2/8.14.2) with ESMTP id n0CAc45I060239;
	Mon, 12 Jan 2009 10:38:04 GMT (envelope-from gavin@FreeBSD.org)
Received: (from ga9@localhost)
	by buffy.york.ac.uk (8.14.2/8.14.2/Submit) id n0CAc4I2060238;
	Mon, 12 Jan 2009 10:38:04 GMT (envelope-from gavin@FreeBSD.org)
X-Authentication-Warning: buffy.york.ac.uk: ga9 set sender to
	gavin@FreeBSD.org using -f
From: Gavin Atkinson <gavin@FreeBSD.org>
To: Pete French <petefrench@ticketswitch.com>
In-Reply-To: <E1LM3uv-0001CD-7X@dilbert.ticketswitch.com>
References: <E1LM3uv-0001CD-7X@dilbert.ticketswitch.com>
Content-Type: text/plain
Content-Transfer-Encoding: 7bit
Date: Mon, 12 Jan 2009 10:38:04 +0000
Message-Id: <1231756684.59797.1.camel@buffy.york.ac.uk>
Mime-Version: 1.0
X-Mailer: Evolution 2.22.2 FreeBSD GNOME Team Port 
X-York-MailScanner: Found to be clean
X-York-MailScanner-From: gavin@freebsd.org
Cc: freebsd-stable@FreeBSD.org
Subject: Re: Lock order reversals using bce in 7.1
X-BeenThere: freebsd-stable@freebsd.org
X-Mailman-Version: 2.1.5
Precedence: list
List-Id: Production branch of FreeBSD source code <freebsd-stable.freebsd.org>
List-Unsubscribe: <http://lists.freebsd.org/mailman/listinfo/freebsd-stable>, 
	<mailto:freebsd-stable-request@freebsd.org?subject=unsubscribe>
List-Archive: <http://lists.freebsd.org/pipermail/freebsd-stable>
List-Post: <mailto:freebsd-stable@freebsd.org>
List-Help: <mailto:freebsd-stable-request@freebsd.org?subject=help>
List-Subscribe: <http://lists.freebsd.org/mailman/listinfo/freebsd-stable>,
	<mailto:freebsd-stable-request@freebsd.org?subject=subscribe>
X-List-Received-Date: Mon, 12 Jan 2009 10:38:09 -0000

On Sun, 2009-01-11 at 17:16 +0000, Pete French wrote:
> Here is a better set of images. This machine was compiled
> with the following config file:
> 
> include         GENERIC
> ident           DEBUG
> 
> options         KDB
> options         DDB
> options         SW_WATCHDOG
> options         DEBUG_VFS_LOCKS
> options         MUTEX_DEBUG
> options         WITNESS
> options         WITNESS_KDB

You don't want WITNESS_KDB, but WITNESS_SKIPSPIN would probably be
sensible to include.

> options         LOCK_PROFILING
> options         INVARIANTS
> options         INVARIANT_SUPPORT
> options         DIAGNOSTIC
> 
> On booting it almost immediately does this:
> 
>         http://www.twisted.org.uk/~pete/71_lor.png

That's due to WITNESS_KDB and probably unrelated to your problems.

Gavin