From owner-freebsd-current@FreeBSD.ORG Sat Dec 25 22:38:06 2004 Return-Path: Delivered-To: freebsd-current@freebsd.org Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id 0D94A16A4CE; Sat, 25 Dec 2004 22:38:06 +0000 (GMT) Received: from critter.freebsd.dk (f170.freebsd.dk [212.242.86.170]) by mx1.FreeBSD.org (Postfix) with ESMTP id 5072E43D3F; Sat, 25 Dec 2004 22:38:05 +0000 (GMT) (envelope-from phk@critter.freebsd.dk) Received: from critter.freebsd.dk (localhost [127.0.0.1]) by critter.freebsd.dk (8.13.1/8.13.1) with ESMTP id iBPMc0ne077131; Sat, 25 Dec 2004 23:38:01 +0100 (CET) (envelope-from phk@critter.freebsd.dk) To: Robert Watson From: "Poul-Henning Kamp" In-Reply-To: Your message of "Sat, 25 Dec 2004 21:40:17 GMT." Date: Sat, 25 Dec 2004 23:38:00 +0100 Message-ID: <77130.1104014280@critter.freebsd.dk> Sender: phk@critter.freebsd.dk cc: Chuck Robey cc: FreeBSD-current@freebsd.org Subject: Re: Reboot instead of debugger/dump from X11? (Re: an accidental way to pull the plug) X-BeenThere: freebsd-current@freebsd.org X-Mailman-Version: 2.1.1 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: Sat, 25 Dec 2004 22:38:06 -0000 In message , Robe rt Watson writes: > >On Sat, 25 Dec 2004, Chuck Robey wrote: > >> I got a little too fast just now, and did something that I shouldn't >> have done, but what's interesting is, FreeBSD decided to pull the plug >> and instantly reboot, which is usually something to be regarded as >> pathological, so I am letting you folks know. I haven't analyzed >> exactly what happened to cause it, actually. > >With the recent 802.11 panic I posted about a bit earlier, I saw something >rather odd: when the panic took place on the normal text console, the >system dropped to the debugger. However, when it took place with X11 >running, I got an "instant reboot" -- no dump, etc. So something odd is >happening during even normal failure modes when X11 is running for me. I >wonder if anyone else is seeing this? Well, it's worse: I often get two-level panics these days and I have no idea how to find out what the first panic was, panicstr isn't even set until after some SMP magic which appearantly is responsible for the second layer of panicing. I think we should start panic() with setting panicstr with an atomic instruction so that we always get the first panic recorded, no matter what. I suspect the preemption code is at fault. -- 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.