From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S272555AbTHEVQ0 (ORCPT ); Tue, 5 Aug 2003 17:16:26 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S272846AbTHEVQZ (ORCPT ); Tue, 5 Aug 2003 17:16:25 -0400 Received: from pix-525-pool.redhat.com ([66.187.233.200]:16148 "EHLO devserv.devel.redhat.com") by vger.kernel.org with ESMTP id S272555AbTHEVQD (ORCPT ); Tue, 5 Aug 2003 17:16:03 -0400 Date: Tue, 5 Aug 2003 21:15:54 +0000 From: Arjan van de Ven To: Andi Kleen Cc: Linus Torvalds , Arjan van de Ven , Andrew Morton , Andi Kleen , linux-kernel@vger.kernel.org Subject: Re: [PATCH] Export touch_nmi_watchdog Message-ID: <20030805211554.B603@devserv.devel.redhat.com> References: <20030805203137.E30256@devserv.devel.redhat.com> <20030805211416.GD31598@colin2.muc.de> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline User-Agent: Mutt/1.2.5.1i In-Reply-To: <20030805211416.GD31598@colin2.muc.de>; from ak@colin2.muc.de on Tue, Aug 05, 2003 at 11:14:16PM +0200 Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Aug 05, 2003 at 11:14:16PM +0200, Andi Kleen wrote: > > Otherwise this will just keep on expanding. > > It does expand on i386 exactly because the watchdog is disabled by default. > > Looks like a mistake to me. It should be on because having usable backtraces > on a deadlock/hang is useful enough that it outweights any other possible > disadvantages. That's especially true for kernels out there at user's boxes, > not just special debugging kernels run by developers. > > [if there should be any hardware where it doesn't work it should be blacklisted > there] the reason it's off is that certain IBM bioses corrupt the eax register on NMI's when they collide with smm stuff... You'd be surprised how tolerant x86 is against such corruptions... but not 100% :)