From owner-freebsd-arch Sun Nov 17 17:34:33 2002 Delivered-To: freebsd-arch@freebsd.org Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id 1D27737B401 for ; Sun, 17 Nov 2002 17:34:32 -0800 (PST) Received: from edgemaster.zombie.org (edgemaster.creighton.edu [147.134.112.68]) by mx1.FreeBSD.org (Postfix) with ESMTP id 7FAC843E42 for ; Sun, 17 Nov 2002 17:34:31 -0800 (PST) (envelope-from smkelly@zombie.org) Received: by edgemaster.zombie.org (Postfix, from userid 1001) id 08BE141513; Sun, 17 Nov 2002 19:34:26 -0600 (CST) Date: Sun, 17 Nov 2002 19:34:25 -0600 From: Sean Kelly To: Alexander Leidinger Cc: Jeff Roberson , arch@FreeBSD.ORG Subject: Re: Software Watchdog Message-ID: <20021118013425.GA90078@edgemaster.zombie.org> References: <20021115191632.U22491-100000@mail.chesapeake.net> <20021117154714.6ddf3c10.Alexander@Leidinger.net> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20021117154714.6ddf3c10.Alexander@Leidinger.net> User-Agent: Mutt/1.5.1i Sender: owner-freebsd-arch@FreeBSD.ORG Precedence: bulk List-ID: List-Archive: (Web Archive) List-Help: (List Instructions) List-Subscribe: List-Unsubscribe: X-Loop: FreeBSD.ORG On Sun, Nov 17, 2002 at 03:47:14PM +0100, Alexander Leidinger wrote: > On Fri, 15 Nov 2002 19:21:08 -0500 (EST) > Jeff Roberson wrote: > > > Sean Kelly has implemented a software watchdog based on input from myself > > and Peter. This works through a simple watcdog daemon that checks in with > > the kernel every so often. The kernel complains via hardclock() if the > > watchdog times out. This will be very useful for debugging hard lockups > > because hardclock() comes in through a fast intr. There are few things > > that will stop hardclock() from firing. > > Is there also the possibility to reset the machine instead of complaining? Presently, the behavior is as follows: * If kernel built with DDB, do backtraces and drop to DDB. * If kernel built without DDB, panic and let the panic reboot the machine. The reason for not using panic() in the case of kernels with DDB is so the panic() is not fatal (i.e. you can return from a watchdog timeout). In the end, I'd like to make the whole thing obey debug.debugger_on_panic if it is present. -- Sean Kelly | PGP KeyID: 77042C7B smkelly@zombie.org | http://www.zombie.org To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-arch" in the body of the message