From owner-freebsd-arch@FreeBSD.ORG  Fri Mar 26 10:38:08 2004
Return-Path: <owner-freebsd-arch@FreeBSD.ORG>
Delivered-To: freebsd-arch@freebsd.org
Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125])
	by hub.freebsd.org (Postfix) with ESMTP
	id 3D6DA16A4CF; Fri, 26 Mar 2004 10:38:08 -0800 (PST)
Received: from harmony.village.org (rover.bsdimp.com [204.144.255.66])
	by mx1.FreeBSD.org (Postfix) with ESMTP
	id 9DCE443D39; Fri, 26 Mar 2004 10:38:07 -0800 (PST)
	(envelope-from imp@bsdimp.com)
Received: from localhost (warner@rover2.village.org [10.0.0.1])
	by harmony.village.org (8.12.10/8.12.9) with ESMTP id i2QIc2kj046680;
	Fri, 26 Mar 2004 11:38:02 -0700 (MST)
	(envelope-from imp@bsdimp.com)
Date: Fri, 26 Mar 2004 11:37:51 -0700 (MST)
Message-Id: <20040326.113751.14204546.imp@bsdimp.com>
To: des@des.no
From: "M. Warner Losh" <imp@bsdimp.com>
In-Reply-To: <xzpekrgf103.fsf@dwp.des.no>
References: <200403260230.i2Q2UTNZ097932@green.homeunix.org>
	<xzpekrgf103.fsf@dwp.des.no>
X-Mailer: Mew version 3.3 on Emacs 21.3 / Mule 5.0 (SAKAKI)
Mime-Version: 1.0
Content-Type: Text/Plain; charset=iso-8859-1
Content-Transfer-Encoding: quoted-printable
cc: das@freebsd.org
cc: tanimura@tanimura.dyndns.org
cc: arch@freebsd.org
Subject: Re: Is MTX_CONTESTED evil?
X-BeenThere: freebsd-arch@freebsd.org
X-Mailman-Version: 2.1.1
Precedence: list
List-Id: Discussion related to FreeBSD architecture
	<freebsd-arch.freebsd.org>
List-Unsubscribe: <http://lists.freebsd.org/mailman/listinfo/freebsd-arch>,
	<mailto:freebsd-arch-request@freebsd.org?subject=unsubscribe>
List-Archive: <http://lists.freebsd.org/pipermail/freebsd-arch>
List-Post: <mailto:freebsd-arch@freebsd.org>
List-Help: <mailto:freebsd-arch-request@freebsd.org?subject=help>
List-Subscribe: <http://lists.freebsd.org/mailman/listinfo/freebsd-arch>,
	<mailto:freebsd-arch-request@freebsd.org?subject=subscribe>
X-List-Received-Date: Fri, 26 Mar 2004 18:38:08 -0000

In message: <xzpekrgf103.fsf@dwp.des.no>
            des@des.no (Dag-Erling Sm=F8rgrav) writes:
: "Brian F. Feldman" <green@FreeBSD.org> writes:
: > Well, that certainly explains the blitz of crashes I had to fix
: > recently!  Since INVARIANTS and WITNESS are on by default, it would=

: > make sense to make ADAPTIVE_MUTEX default to catch more bugs.
: =

: Making ADAPTIVE_MUTEXES default will not catch more bugs, it will jus=
t
: piss off users.

I think that if we don't fix the class of bugs that AM points out,
we'll ruin our reputation as a quality system in the long run.  Maybe
they are so pervasive that we don't want to turn it on by default just
yet, but there will come a time we turn it on, just like we turned on
WITNESS and INVARIANTS to get better coverage on our testing.

Warner