From owner-freebsd-stable@FreeBSD.ORG Mon Aug 23 11:08:50 2010 Return-Path: Delivered-To: freebsd-stable@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id D766F10656A9 for ; Mon, 23 Aug 2010 11:08:50 +0000 (UTC) (envelope-from phk@critter.freebsd.dk) Received: from phk.freebsd.dk (phk.freebsd.dk [130.225.244.222]) by mx1.freebsd.org (Postfix) with ESMTP id 853A28FC28 for ; Mon, 23 Aug 2010 11:08:50 +0000 (UTC) Received: from critter.freebsd.dk (critter.freebsd.dk [192.168.61.3]) by phk.freebsd.dk (Postfix) with ESMTP id 5AB953F5B6; Mon, 23 Aug 2010 10:53:47 +0000 (UTC) Received: from critter.freebsd.dk (localhost [127.0.0.1]) by critter.freebsd.dk (8.14.4/8.14.4) with ESMTP id o7NArkdr085638; Mon, 23 Aug 2010 10:53:47 GMT (envelope-from phk@critter.freebsd.dk) To: Jeremy Chadwick From: "Poul-Henning Kamp" In-Reply-To: Your message of "Mon, 23 Aug 2010 03:34:12 MST." <20100823103412.GA21044@icarus.home.lan> Date: Mon, 23 Aug 2010 10:53:46 +0000 Message-ID: <85637.1282560826@critter.freebsd.dk> Sender: phk@critter.freebsd.dk Cc: freebsd-stable@freebsd.org Subject: Re: Watchdog not being disabled while dumping core X-BeenThere: freebsd-stable@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Production branch of FreeBSD source code List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Mon, 23 Aug 2010 11:08:50 -0000 In message <20100823103412.GA21044@icarus.home.lan>, Jeremy Chadwick writes: >It was brought to my attention that on FreeBSD with a hardware watchdog >in use (e.g. ichwd(4) + watchdogd(8)), once the kernel panics, it's >quite possible for the watchdog to fire (reboot the system) once the >panic has happened. This issue basically inhibits the ability for a >system with a hardware watchdog in place to be able to successfully >complete doadump(). The good news is that the watchdog hopefully gets your system back on the air, even if the dumping hangs. If it is decided to reset/disarm the watchdog before a dump, please make that a sysctl tunable. -- 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.