From owner-freebsd-hackers Tue Dec 7 0: 2: 4 1999 Delivered-To: freebsd-hackers@freebsd.org Received: from ind.alcatel.com (postal.xylan.com [208.8.0.248]) by hub.freebsd.org (Postfix) with ESMTP id 8F22D14E1C; Tue, 7 Dec 1999 00:01:55 -0800 (PST) (envelope-from wes@softweyr.com) Received: from mailhub.xylan.com (mailhub [198.206.181.70]) by ind.alcatel.com (8.9.3+Sun/8.9.1 (ind.alcatel.com 3.0 [OUT])) with SMTP id AAA12168; Tue, 7 Dec 1999 00:01:01 -0800 (PST) X-Origination-Site: Received: from omni.xylan.com by mailhub.xylan.com (SMI-8.6/SMI-SVR4 (mailhub 2.1 [HUB])) id AAA08796; Tue, 7 Dec 1999 00:01:00 -0800 Received: from softweyr.com ([204.68.178.39]) by omni.xylan.com (4.1/SMI-4.1 (xylan engr [SPOOL])) id AA00928; Tue, 7 Dec 99 00:00:56 PST Message-Id: <384CBED6.FECBC219@softweyr.com> Date: Tue, 07 Dec 1999 01:01:26 -0700 From: Wes Peters Organization: Softweyr LLC X-Mailer: Mozilla 4.61 [en] (X11; I; FreeBSD 3.3-RELEASE i386) X-Accept-Language: en Mime-Version: 1.0 To: Andrew Reilly Cc: Matthew Dillon , Kris Kennaway , freebsd-hackers@FreeBSD.ORG Subject: Re: PCI DMA lockups in 3.2 (3.3 maybe?) References: <199912050514.VAA58998@apollo.backplane.com> <3849FD95.F0434263@softweyr.com> <199912050646.WAA59445@apollo.backplane.com> <384B228D.FFE9728@softweyr.com> <19991207123419.A76129@gurney.reilly.home> Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Sender: owner-freebsd-hackers@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.ORG Andrew Reilly wrote: > > On Sun, Dec 05, 1999 at 07:42:21PM -0700, Wes Peters wrote: > > Software > > is created by humans, and humans are fallible, therefore the software > > is also fallible. > > No, that doesn't logically follow. Just because it's possible > for humans to make mistakes doesn't mean that it's impossible to > do or make something (eventually) without mistakes. And in theory, theory is better than practice. In practice, it rarely is. I've worked on formal proofs for software, and in the most rigorous software evaluations ever performed - the Nuclear Safety Cross Check Analysis for intercontinental ballistic missiles. With the exception of TeX, *no* software is bug-free. In my extensive experience, no software with the exception of TeX is free of serious bugs. This includes the ICBM control system. Your belief or lack thereof doesn't change the existence of the bugs, it just leads YOU to be surprised when they crop up in the oddest ways, while I am not. BTW, if you know anyone at Boeing, ask them if they ever *really* got the "uncommanded flap excursion" bug fixed, or if this is what killed EgyptAir 800. Watch them go into fits. If you can't PROVE it's correct, how much empirical testing are you going to accept? -- "Where am I, and what am I doing in this handbasket?" Wes Peters Softweyr LLC wes@softweyr.com http://softweyr.com/ To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-hackers" in the body of the message