From owner-freebsd-current@FreeBSD.ORG Wed Jan 12 13:13:45 2011 Return-Path: Delivered-To: freebsd-current@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id 6171B106564A for ; Wed, 12 Jan 2011 13:13:45 +0000 (UTC) (envelope-from nh@tisys.org) Received: from s15373095.onlinehome-server.info (s15373095.onlinehome-server.info [87.106.45.78]) by mx1.freebsd.org (Postfix) with ESMTP id E68928FC17 for ; Wed, 12 Jan 2011 13:13:44 +0000 (UTC) Received: from Spooler by s15373095.onlinehome-server.info (Mercury/32 v4.72) ID MO000F5E; 12 Jan 2011 14:13:45 +0100 Received: from spooler by luwug.de (Mercury/32 v4.72); 12 Jan 2011 13:43:16 +0100 Received: from Nemesis (87.193.143.230) by s15373095.onlinehome-server.info (Mercury/32 v4.72) with ESMTP ID MG000F5D; 12 Jan 2011 13:43:11 +0100 Message-ID: From: "Nils Holland" To: "C. P. Ghost" , "Chuck Swiger" References: In-Reply-To: Date: Wed, 12 Jan 2011 13:43:10 +0100 Organization: Ti Systems MIME-Version: 1.0 Content-Type: text/plain; format=flowed; charset="iso-8859-1"; reply-type=original Content-Transfer-Encoding: 7bit X-Priority: 3 X-MSMail-Priority: Normal Importance: Normal X-Mailer: Microsoft Windows Live Mail 15.4.3508.1109 X-MimeOLE: Produced By Microsoft MimeOLE V15.4.3508.1109 Cc: David DEMELIER , freebsd-current@freebsd.org Subject: Re: why panic(9) ? X-BeenThere: freebsd-current@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Discussions about the use of FreeBSD-current List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Wed, 12 Jan 2011 13:13:45 -0000 C. P. Ghost wrote: > As far as I know, Windows NT is a microkernel arch, and > faulty drivers, often provided by external vendors would not > bring that system (as much as we hate or despise its > Windows OS personality that runs on top of it) to a complete halt. I don't know ... when Windows crashes (I'm no fan of it either, but anyway) and you ask Microsoft about it, then it's most of the time an external driver that is responsible. Graphics card driver seem to be the cause most often, but other stuff as well. Here at work, we had a Windows Vista (moving the focus of this discussion away from Windows 2000) machine that crashed every time it was attempted to establisch a PPTP VPN connection. The reason, as the blue screen clearly showed, was a faulty driver that was part of a firewall made by AVG. So I would vote for exactly the contrary: Windows itself, in terms of "just the Microsoft components" is fairly stable, and it's third-party drivers that tend to bring it down most of the time. Having a job in which I have to support people working on Windows, I can say for sure that there's no such thing in Windows that prevents third-party system level stuff to bring down the system. ;-) But back to the topic itself: Of course panics are useful. It's not a feature you'll use to advertise your operating system with, but an appropriate comparison is this: When you no longer know what you're doing, it's better to just stop immediately. And that's what a panic does: When the kernel has somehow gotten into an "undefined" state it cannot cope with, it just pulls the plug before any additional damage can be done. Totally sane thing. Of course, improving the kernel so that such "undefined states it cannot cope with" occur as little frequently as possible makes sense (and FreeBSD is certainly very good in that area), just "removing" panic doesn't make any sense. When somehow you've gotten in front of a tunnel and there's a train approaching, you don't believe that just standing still and closing your eyes will save you. ;-) Greetings, Nils