From owner-freebsd-hackers@FreeBSD.ORG  Thu May 31 15:58:04 2012
Return-Path: <owner-freebsd-hackers@FreeBSD.ORG>
Delivered-To: freebsd-hackers@freebsd.org
Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34])
	by hub.freebsd.org (Postfix) with ESMTP id D1D0F1065693;
	Thu, 31 May 2012 15:58:04 +0000 (UTC) (envelope-from jhb@freebsd.org)
Received: from bigwig.baldwin.cx (bigknife-pt.tunnel.tserv9.chi1.ipv6.he.net
	[IPv6:2001:470:1f10:75::2])
	by mx1.freebsd.org (Postfix) with ESMTP id 06D998FC21;
	Thu, 31 May 2012 15:58:00 +0000 (UTC)
Received: from jhbbsd.localnet (unknown [209.249.190.124])
	by bigwig.baldwin.cx (Postfix) with ESMTPSA id 7C7D3B995;
	Thu, 31 May 2012 11:57:59 -0400 (EDT)
From: John Baldwin <jhb@freebsd.org>
To: Mark Felder <feld@feld.me>
Date: Thu, 31 May 2012 11:57:42 -0400
User-Agent: KMail/1.13.5 (FreeBSD/8.2-CBSD-20110714-p13; KDE/4.5.5; amd64; ; )
References: <op.wbwe9s0k34t2sn@tech304> <201205311048.45813.jhb@freebsd.org>
	<op.we6hsx0m34t2sn@tech304>
In-Reply-To: <op.we6hsx0m34t2sn@tech304>
MIME-Version: 1.0
Content-Type: Text/Plain;
  charset="utf-8"
Content-Transfer-Encoding: 7bit
Message-Id: <201205311157.42909.jhb@freebsd.org>
X-Greylist: Sender succeeded SMTP AUTH, not delayed by milter-greylist-4.2.7
	(bigwig.baldwin.cx); Thu, 31 May 2012 11:57:59 -0400 (EDT)
Cc: freebsd-hackers@freebsd.org, freebsd-questions@freebsd.org
Subject: Re: Please help me diagnose this crazy VMWare/FreeBSD 8.x crash
X-BeenThere: freebsd-hackers@freebsd.org
X-Mailman-Version: 2.1.5
Precedence: list
List-Id: Technical Discussions relating to FreeBSD
	<freebsd-hackers.freebsd.org>
List-Unsubscribe: <http://lists.freebsd.org/mailman/listinfo/freebsd-hackers>, 
	<mailto:freebsd-hackers-request@freebsd.org?subject=unsubscribe>
List-Archive: <http://lists.freebsd.org/pipermail/freebsd-hackers>
List-Post: <mailto:freebsd-hackers@freebsd.org>
List-Help: <mailto:freebsd-hackers-request@freebsd.org?subject=help>
List-Subscribe: <http://lists.freebsd.org/mailman/listinfo/freebsd-hackers>,
	<mailto:freebsd-hackers-request@freebsd.org?subject=subscribe>
X-List-Received-Date: Thu, 31 May 2012 15:58:04 -0000

On Thursday, May 31, 2012 11:11:11 am Mark Felder wrote:
> So when this hang happens, there never is a real panic. It just sits in a  
> state which I describe as like being in a deadlock. How would I go about  
> getting a crashdump if it never panics? Is it possible to do the dump over  
> a network or something because I don't believe it can write through the  
> controller at all.

You can break into ddb and run 'call doadump'.  It should use polled IO, so 
there is a slight chance of it working.

> Also, thank you for the KTR_SCHED tip. This is the type of info I was  
> looking for. Unfortunately I've only ever seen this crash once on a kernel  
> with debugging enabled. The machine which is currently prepared to do this  
> work used to crash a few times a week and now it has 70 days uptime...  
> however, it is an example of a machine with mpt0 and em0 sharing an IRQ so  
> I might be able to trigger it using Dane's method.
> 
> $ vmstat -i
> interrupt                          total       rate
> irq1: atkbd0                         392          0
> irq6: fdc0                             9          0
> irq14: ata0                           34          0
> irq18: em0 mpt0               1189748491        218
> cpu0: timer                   2174263198        400
> Total                         3364012124        619
> 
> 
> I'm doing my best to get you guys the info you need, but this is one heck  
> of a Heisenbug...

Thanks.

-- 
John Baldwin