From owner-freebsd-amd64@FreeBSD.ORG  Mon Apr  4 15:43:09 2005
Return-Path: <owner-freebsd-amd64@FreeBSD.ORG>
Delivered-To: freebsd-amd64@freebsd.org
Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125])
	by hub.freebsd.org (Postfix) with ESMTP id 245AD16A4CE
	for <freebsd-amd64@freebsd.org>; Mon,  4 Apr 2005 15:43:09 +0000 (GMT)
Received: from pigeon.infotechfl.com (mailrelay.infotechfl.com
	[209.251.147.6])
	by mx1.FreeBSD.org (Postfix) with ESMTP id 2433343D41
	for <freebsd-amd64@freebsd.org>;
	Mon,  4 Apr 2005 15:43:08 +0000 (GMT)
	(envelope-from gmulder@infotechfl.com)
Received: from [172.20.0.75] (gmulder.infotechfl.com [172.20.0.75])
	by pigeon.infotechfl.com (8.11.6/8.11.6) with ESMTP id j34Djh227199
	for <freebsd-amd64@freebsd.org>; Mon, 4 Apr 2005 09:45:43 -0400
Message-ID: <42514508.90303@infotechfl.com>
Date: Mon, 04 Apr 2005 09:45:44 -0400
From: Gary Mu1der <gmulder@infotechfl.com>
User-Agent: Mozilla Thunderbird 1.0.2 (Windows/20050317)
X-Accept-Language: en-us, en
MIME-Version: 1.0
To: freebsd-amd64@freebsd.org
References: <f0111a98c01333b3c306c81d10294de4@khera.org>
	<Pine.SOC.4.61.0503300229560.3181@tea.blinkenlights.nl>
	<3f9aa5aef19c41837cce1563e2c97a21@khera.org> <424C215E.5080201@infotechfl.com>
	<b6c7cfb181756fdfa3593f64223cb08a@khera.org> <424C4EED.5070601@infotechfl.com>
	<1112312243.6323.10.camel@lanshark.dmv.com> <424D58F7.1010005@infotechfl.com>
	<cab069d57aee4d9ba99d5ed9ef6b94c1@khera.org> <424DA4B3.3070703@infotechfl.com>
	<20050401201907.U95587@carver.gumbysoft.com>
In-Reply-To: <20050401201907.U95587@carver.gumbysoft.com>
Content-Type: text/plain; charset=ISO-8859-1; format=flowed
Content-Transfer-Encoding: 7bit
Subject: Re: Tyan k8sr lockups
X-BeenThere: freebsd-amd64@freebsd.org
X-Mailman-Version: 2.1.1
Precedence: list
List-Id: Porting FreeBSD to the AMD64 platform <freebsd-amd64.freebsd.org>
List-Unsubscribe: <http://lists.freebsd.org/mailman/listinfo/freebsd-amd64>,
	<mailto:freebsd-amd64-request@freebsd.org?subject=unsubscribe>
List-Archive: <http://lists.freebsd.org/pipermail/freebsd-amd64>
List-Post: <mailto:freebsd-amd64@freebsd.org>
List-Help: <mailto:freebsd-amd64-request@freebsd.org?subject=help>
List-Subscribe: <http://lists.freebsd.org/mailman/listinfo/freebsd-amd64>,
	<mailto:freebsd-amd64-request@freebsd.org?subject=subscribe>
X-List-Received-Date: Mon, 04 Apr 2005 15:43:09 -0000

I had suspected that, but I've done the same on a P4 system with 5.3REL, 
Solaris on Sparc (although I don't know if Sparc has memory mapped I/O), 
and other Unixes, and had no problems.

It was a quick a dirty way to stress the memory and CPU.

Thanks for the reply,
Gary

Doug White wrote:
> On Fri, 1 Apr 2005, Gary Mu1der wrote:
> 
> 
>>I have isolated the crash to the following dd command:
>>
>>	dd if=/dev/mem of=/dev/null bs=1024k skip=4040 count=1
> 
> 
> Reading from random places in /dev/mem will cause unpredicatable behavior.
> Memory at that offset is in PCI memory-mapped device space, and reading
> from there may disrupt the PCI bridge, enable or disable interrupts, or
> worse.
>