From owner-freebsd-net@FreeBSD.ORG  Tue Feb  1 05:53:44 2011
Return-Path: <owner-freebsd-net@FreeBSD.ORG>
Delivered-To: freebsd-net@freebsd.org
Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34])
	by hub.freebsd.org (Postfix) with ESMTP id D30E81065675;
	Tue,  1 Feb 2011 05:53:44 +0000 (UTC)
	(envelope-from egrosbein@rdtc.ru)
Received: from eg.sd.rdtc.ru (eg.sd.rdtc.ru [62.231.161.221])
	by mx1.freebsd.org (Postfix) with ESMTP id 3FD098FC0A;
	Tue,  1 Feb 2011 05:53:43 +0000 (UTC)
Received: from eg.sd.rdtc.ru (localhost [127.0.0.1])
	by eg.sd.rdtc.ru (8.14.4/8.14.4) with ESMTP id p115rfgF056439;
	Tue, 1 Feb 2011 11:53:41 +0600 (NOVT)
	(envelope-from egrosbein@rdtc.ru)
Message-ID: <4D479FE0.70809@rdtc.ru>
Date: Tue, 01 Feb 2011 11:53:36 +0600
From: Eugene Grosbein <egrosbein@rdtc.ru>
User-Agent: Mozilla/5.0 (X11; U; FreeBSD i386; ru-RU;
	rv:1.9.2.13) Gecko/20110112 Thunderbird/3.1.7
MIME-Version: 1.0
To: John Baldwin <jhb@freebsd.org>
References: <4D3011DB.9050900@frasunek.com>	<201101141437.55421.jhb@freebsd.org>
	<4D46575A.802@rdtc.ru> <201101311146.43119.jhb@freebsd.org>
In-Reply-To: <201101311146.43119.jhb@freebsd.org>
Content-Type: text/plain; charset=us-ascii
Content-Transfer-Encoding: 7bit
Cc: freebsd-net@freebsd.org
Subject: Re: panic: bufwrite: buffer is not busy???
X-BeenThere: freebsd-net@freebsd.org
X-Mailman-Version: 2.1.5
Precedence: list
List-Id: Networking and TCP/IP with FreeBSD <freebsd-net.freebsd.org>
List-Unsubscribe: <http://lists.freebsd.org/mailman/listinfo/freebsd-net>,
	<mailto:freebsd-net-request@freebsd.org?subject=unsubscribe>
List-Archive: <http://lists.freebsd.org/pipermail/freebsd-net>
List-Post: <mailto:freebsd-net@freebsd.org>
List-Help: <mailto:freebsd-net-request@freebsd.org?subject=help>
List-Subscribe: <http://lists.freebsd.org/mailman/listinfo/freebsd-net>,
	<mailto:freebsd-net-request@freebsd.org?subject=subscribe>
X-List-Received-Date: Tue, 01 Feb 2011 05:53:44 -0000

On 31.01.2011 22:46, John Baldwin wrote:

>># gdb kernel
>> GNU gdb 6.1.1 [FreeBSD]
>> Copyright 2004 Free Software Foundation, Inc.
>> GDB is free software, covered by the GNU General Public License, and you are
>> welcome to change it and/or distribute copies of it under certain 
> conditions.
>> Type "show copying" to see the conditions.
>> There is absolutely no warranty for GDB.  Type "show warranty" for details.
>> This GDB was configured as "amd64-marcel-freebsd"...
>> (gdb) l *0xffffffff803c1315
>> 0xffffffff803c1315 is in ng_address_hook 
> (/home/src/sys/netgraph/ng_base.c:3504).
>> 3499             * Quick sanity check..
>> 3500             * Since a hook holds a reference on it's node, once we know
>> 3501             * that the peer is still connected (even if invalid,) we 
> know
>> 3502             * that the peer node is present, though maybe invalid.
>> 3503             */
>> 3504            if ((hook == NULL) ||
>> 3505                NG_HOOK_NOT_VALID(hook) ||
>> 3506                NG_HOOK_NOT_VALID(peer = NG_HOOK_PEER(hook)) ||
>> 3507                NG_NODE_NOT_VALID(peernode = NG_PEER_NODE(hook))) {
>> 3508                    NG_FREE_ITEM(item);
> 
> Hmmm.  I think you might have a hardware problem.  Notice the fault address, 
> it is 0x200000030.  Can you do 'x/i <instruction pointer>'?

(gdb) x/i 0xffffffff803c1315
0xffffffff803c1315 <ng_address_hook+37>:        testb  $0x1,0x28(%rdx)
(gdb) x/i *0xffffffff803c1315
0x12842f6:      Cannot access memory at address 0x12842f6

> I suspect it is 
> doing a memory access from that has a constant offset of 0x30, in which case 
> the original pointer was 0x200000000, meaning it would be NULL except it has a 
> single-bit error.  That would likely be caused by a hardware issue such as 
> failing RAM, etc.

This is SuperMicro server with ECC RAM. I've already tested it with memtest86+
during long time, no memory problems found.

Eugene Grosbein