From owner-freebsd-hackers@FreeBSD.ORG  Fri Sep 26 03:51:19 2003
Return-Path: <owner-freebsd-hackers@FreeBSD.ORG>
Delivered-To: freebsd-hackers@freebsd.org
Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125])
	by hub.freebsd.org (Postfix) with ESMTP id 133BC16A4B3
	for <hackers@freebsd.org>; Fri, 26 Sep 2003 03:51:19 -0700 (PDT)
Received: from critter.freebsd.dk (critter.freebsd.dk [212.242.86.163])
	by mx1.FreeBSD.org (Postfix) with ESMTP id E4A854400B
	for <hackers@freebsd.org>; Fri, 26 Sep 2003 03:51:17 -0700 (PDT)
	(envelope-from phk@phk.freebsd.dk)
Received: from critter.freebsd.dk (localhost [127.0.0.1])
	by critter.freebsd.dk (8.12.9/8.12.9) with ESMTP id h8QAp9LG072700;
	Fri, 26 Sep 2003 12:51:14 +0200 (CEST)
	(envelope-from phk@phk.freebsd.dk)
To: Stefan Farfeleder <stefan@fafoe.narf.at>
From: "Poul-Henning Kamp" <phk@phk.freebsd.dk>
In-Reply-To: Your message of "Wed, 17 Sep 2003 17:55:45 +0200."
             <20030917155544.GG697@wombat.fafoe.narf.at> 
Date: Fri, 26 Sep 2003 12:51:09 +0200
Message-ID: <72699.1064573469@critter.freebsd.dk>
cc: hackers@freebsd.org
Subject: Re: Major numbers reclaiming for make_dev/MAJOR_AUTO 
X-BeenThere: freebsd-hackers@freebsd.org
X-Mailman-Version: 2.1.1
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: Fri, 26 Sep 2003 10:51:19 -0000


Hi Stefan,

Your patch will work OK in a lot of settings, but there are
unfortunately also some very nasty cases where it will fail
miserably because refcounting dev_t's is not safe yet.

There are a few remaining issues to deal with before we can
properly refcount dev_t's, and that is more or less all the
places in the kernel which uses makedev().

As you may have noticed I've started evicting these from the
console related code.

-- 
Poul-Henning Kamp       | UNIX since Zilog Zeus 3.20
phk@FreeBSD.ORG         | TCP/IP since RFC 956
FreeBSD committer       | BSD since 4.3-tahoe    
Never attribute to malice what can adequately be explained by incompetence.