From owner-freebsd-current@FreeBSD.ORG  Wed Feb 11 17:30:38 2009
Return-Path: <owner-freebsd-current@FreeBSD.ORG>
Delivered-To: freebsd-current@freebsd.org
Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34])
	by hub.freebsd.org (Postfix) with ESMTP id E56E21065670
	for <freebsd-current@freebsd.org>; Wed, 11 Feb 2009 17:30:38 +0000 (UTC)
	(envelope-from alan.l.cox@gmail.com)
Received: from rn-out-0910.google.com (rn-out-0910.google.com [64.233.170.185])
	by mx1.freebsd.org (Postfix) with ESMTP id 9C66B8FC13
	for <freebsd-current@freebsd.org>; Wed, 11 Feb 2009 17:30:38 +0000 (UTC)
	(envelope-from alan.l.cox@gmail.com)
Received: by rn-out-0910.google.com with SMTP id k32so287928rnd.12
	for <freebsd-current@freebsd.org>; Wed, 11 Feb 2009 09:30:38 -0800 (PST)
DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=gamma;
	h=domainkey-signature:mime-version:received:in-reply-to:references
	:date:message-id:subject:from:to:cc:content-type;
	bh=JQdoke7zntHIc6SuavGS16ok2QfHZO0Z6vpC0dkzEa8=;
	b=WfbLchVkSBb6Mdmv7uS9SUXbCqLbYYPpGXjEegXwJ/3Ybc6eh2sEfD/n3vfkr5je5w
	VD7MixGY+fg6f5N43Hy1tmRaBXDsr+rWZ9ZUomUZ2No3ns0UCpFrGdUIZt5/1QI4gDCm
	67JMjcR+BKwDr5UK25hDks8H2kAQZof6gY5A0=
DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma;
	h=mime-version:in-reply-to:references:date:message-id:subject:from:to
	:cc:content-type;
	b=V5Ch8OoomeLyhAhpTB4CMbgykrmyBTNGn0ZvgztWdgXZIp10cmPi1H/hpmsj+AjOPW
	fnh5LLsPByfZyAAxJYL1NxLJaAK4RBQDQQcBN/a8d7hpYkHjtffdvO4XbYWUR3ljnwVk
	tlhT/EFT7thZHkhjWUx16uFHmdxo1hwaWu37U=
MIME-Version: 1.0
Received: by 10.151.14.5 with SMTP id r5mr49409ybi.193.1234371609228; Wed, 11 
	Feb 2009 09:00:09 -0800 (PST)
In-Reply-To: <gmsnin$qg9$1@ger.gmane.org>
References: <gl7hu4$q7k$1@ger.gmane.org> <gmqbv1$jhe$1@ger.gmane.org>
	<gmsnin$qg9$1@ger.gmane.org>
Date: Wed, 11 Feb 2009 11:00:09 -0600
Message-ID: <ca3526250902110900r6e3703c2gf4f63678949a2e33@mail.gmail.com>
From: Alan Cox <alan.l.cox@gmail.com>
To: Mark Atkinson <atkin901@yahoo.com>
Content-Type: text/plain; charset=ISO-8859-1
Content-Transfer-Encoding: 7bit
X-Content-Filtered-By: Mailman/MimeDel 2.1.5
Cc: freebsd-current@freebsd.org, alc@cs.rice.edu
Subject: Re: memory alignment problems with -current on amd64? [Found Cause]
X-BeenThere: freebsd-current@freebsd.org
X-Mailman-Version: 2.1.5
Precedence: list
List-Id: Discussions about the use of FreeBSD-current
	<freebsd-current.freebsd.org>
List-Unsubscribe: <http://lists.freebsd.org/mailman/listinfo/freebsd-current>, 
	<mailto:freebsd-current-request@freebsd.org?subject=unsubscribe>
List-Archive: <http://lists.freebsd.org/pipermail/freebsd-current>
List-Post: <mailto:freebsd-current@freebsd.org>
List-Help: <mailto:freebsd-current-request@freebsd.org?subject=help>
List-Subscribe: <http://lists.freebsd.org/mailman/listinfo/freebsd-current>,
	<mailto:freebsd-current-request@freebsd.org?subject=subscribe>
X-List-Received-Date: Wed, 11 Feb 2009 17:30:39 -0000

On Tue, Feb 10, 2009 at 2:20 PM, Mark Atkinson <atkin901@yahoo.com> wrote:
[snip]
>
>
>
> Well, taking the information I knew -- OCT 15th == good, Mid DEC == BAD,
> I trolled every commit logged between.   Eventually I found this one:
>
> http://svn.freebsd.org/viewvc/base?view=revision&revision=185715
>
> http://docs.freebsd.org/cgi/mid.cgi?200812061937.mB6JbqAI003273
>
> I set vm.pmap.pg_ps_enabled="0" in /boot/loader.conf, and
> was able to complete buildworld and -j16 buildworld and -j8 buildkernel
> no problem.
>
> It appears superpage mapping causes alignment problems on this box.


Can you please provide more detailed information about this machine, in
particular, the processor including the revision?  It would also be helpful
to see what gdb says about a couple of these crashes, specifically, the
machine registers at the time of the exception.

Thanks in advance,
Alan