From owner-freebsd-hackers  Sun Oct 10 20: 2:48 1999
Delivered-To: freebsd-hackers@freebsd.org
Received: from mail1.atl.bellsouth.net (mail1.atl.bellsouth.net [205.152.0.28])
	by hub.freebsd.org (Postfix) with ESMTP id 32B8014C02
	for <freebsd-hackers@FreeBSD.ORG>; Sun, 10 Oct 1999 20:02:45 -0700 (PDT)
	(envelope-from wghicks@bellsouth.net)
Received: from wghicks.bellsouth.net (host-216-78-37-222.ath.bellsouth.net [216.78.37.222])
	by mail1.atl.bellsouth.net (3.3.4alt/0.75.2) with ESMTP id WAA14390;
	Sun, 10 Oct 1999 22:58:11 -0400 (EDT)
Received: from wghicks.bellsouth.net (IDENT:wghicks@localhost [127.0.0.1])
	by wghicks.bellsouth.net (8.9.3/8.9.2) with ESMTP id XAA47903;
	Sun, 10 Oct 1999 23:08:19 -0400 (EDT)
	(envelope-from wghicks@wghicks.bellsouth.net)
Message-Id: <199910110308.XAA47903@bellsouth.net>
To: nate@mt.sri.com (Nate Williams)
Cc: freebsd-hackers@FreeBSD.ORG
Subject: Re: KLDs 
In-reply-to: Your message of "Sun, 10 Oct 1999 20:21:09 MDT."
             <199910110221.UAA12619@mt.sri.com> 
Date: Sun, 10 Oct 1999 23:08:19 -0400
From: W Gerald Hicks <wghicks@bellsouth.net>
Sender: owner-freebsd-hackers@FreeBSD.ORG
Precedence: bulk
X-Loop: FreeBSD.ORG

> >  Could things be done in such a way that like QNX, it can
> > kill and restart a misbehaving driver?  What other cool things can be
> > done?
> 
> QNX doesn't do that.

> Actually, in many cases it does.  There are numerous advantages in a
> well-designed/optimized micro-kernel that FreeBSD will never have.

Well, the implication was that QNX implements this as a kernel
policy and that it's done automatically.  A handful of drivers
can be stopped and restarted, notably the network devices.

The QNX filesystem resource managers and disk device drivers are
notoriously finicky and aren't restartable in the general sense.

Still, I like QNX a lot and have a major telecomm app widely
deployed on it, going on five years in the field now.

> However, as has been shown by the plethora of poor micro-kernel
> implementations (QNX not withstanding), it's hard to implement a
> well-designed/optimized micro-kernel, especially one that is not
> architecture dependent.

Amen!  :-)

Cheers,

Jerry Hicks
wghicks@bellsouth.net


To Unsubscribe: send mail to majordomo@FreeBSD.org
with "unsubscribe freebsd-hackers" in the body of the message