From owner-freebsd-current@FreeBSD.ORG  Thu Mar  4 20:29:21 2004
Return-Path: <owner-freebsd-current@FreeBSD.ORG>
Delivered-To: freebsd-current@freebsd.org
Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125])
	by hub.freebsd.org (Postfix) with ESMTP
	id 1237E16A4CF; Thu,  4 Mar 2004 20:29:21 -0800 (PST)
Received: from fledge.watson.org (fledge.watson.org [204.156.12.50])
	by mx1.FreeBSD.org (Postfix) with ESMTP
	id AD19843D41; Thu,  4 Mar 2004 20:29:20 -0800 (PST)
	(envelope-from robert@fledge.watson.org)
Received: from fledge.watson.org (localhost [127.0.0.1])
	by fledge.watson.org (8.12.10/8.12.10) with ESMTP id i254S4DL060687;
	Thu, 4 Mar 2004 23:28:04 -0500 (EST)
	(envelope-from robert@fledge.watson.org)
Received: from localhost (robert@localhost)i254S4jm060684;
	Thu, 4 Mar 2004 23:28:04 -0500 (EST)
	(envelope-from robert@fledge.watson.org)
Date: Thu, 4 Mar 2004 23:28:04 -0500 (EST)
From: Robert Watson <rwatson@freebsd.org>
X-Sender: robert@fledge.watson.org
To: "Alan L. Cox" <alc@imimic.com>
In-Reply-To: <4047F3F8.1080207@imimic.com>
Message-ID: <Pine.NEB.3.96L.1040304232746.56322C-100000@fledge.watson.org>
MIME-Version: 1.0
Content-Type: TEXT/PLAIN; charset=US-ASCII
cc: alc@freebsd.org
cc: Nate Lawson <nate@root.org>
cc: current@freebsd.org
cc: Marcel Moolenaar <marcel@xcllnt.net>
Subject: Re: bug in vm_contig.c? [was: Re: ACPI crash with recent changes]
X-BeenThere: freebsd-current@freebsd.org
X-Mailman-Version: 2.1.1
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: Fri, 05 Mar 2004 04:29:21 -0000


On Thu, 4 Mar 2004, Alan L. Cox wrote:

> Please test the attached patch instead.  In order to avoid a race
> condition, it is necessary for the loop to begin with "start" rather
> than "start + 1".  What is both unnecessary and wrong is the physical
> contiguity check.  (My bad. :-()  In other words, the test that the page
> is still free must be repeated because of the dropping of the free page
> queue lock, but contiguity once true is always true. 

Using this patch, my testbox boots just fine.

Robert N M Watson             FreeBSD Core Team, TrustedBSD Projects
robert@fledge.watson.org      Senior Research Scientist, McAfee Research


> 
> Regards,
> Alan
> 
>