From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932241AbXCEU2R (ORCPT ); Mon, 5 Mar 2007 15:28:17 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S932255AbXCEU2R (ORCPT ); Mon, 5 Mar 2007 15:28:17 -0500 Received: from mx2.mail.elte.hu ([157.181.151.9]:37002 "EHLO mx2.mail.elte.hu" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932241AbXCEU2Q (ORCPT ); Mon, 5 Mar 2007 15:28:16 -0500 Date: Mon, 5 Mar 2007 21:26:48 +0100 From: Ingo Molnar To: Andi Kleen Cc: Len Brown , Linus Torvalds , Andrew Morton , linux-kernel@vger.kernel.org, Arjan van de Ven , Adrian Bunk , Alan Cox Subject: Re: [patch] disable NMI watchdog by default Message-ID: <20070305202648.GA2184@elte.hu> References: <20070305122011.GA16133@elte.hu> <200703051242.45635.lenb@kernel.org> <200703052054.45292.ak@suse.de> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <200703052054.45292.ak@suse.de> User-Agent: Mutt/1.4.2.2i X-ELTE-VirusStatus: clean X-ELTE-SpamScore: -2.0 X-ELTE-SpamLevel: X-ELTE-SpamCheck: no X-ELTE-SpamVersion: ELTE 2.0 X-ELTE-SpamCheck-Details: score=-2.0 required=5.9 tests=BAYES_00 autolearn=no SpamAssassin version=3.1.7 -2.0 BAYES_00 BODY: Bayesian spam probability is 0 to 1% [score: 0.0000] Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org * Andi Kleen wrote: > > There are multiple machines not booting because of nmi_watchdog. > > Some of them are documented here: > > http://bugzilla.kernel.org/show_bug.cgi?id=7839 > > > > We used to think this was the "nolapic" bug, > > but it is actually the "nmi_watchdog=0" bug. > > I thought that one was worked around by Ingo's patch to not do nmi > watchdog during ACPI methods, wasn't it? unfortunately that only made the lockups on my laptop rarer, it didnt totally solve it. My workaround was only done for init acpi methods (bootup) - it was getting really ugly when i tried to extend it to all ACPI execution. I'd guess the situation on those other systems is similar. Maybe we could take only the 32-bit side of my patch, because that's what is most affected by legacies. Although i suspect Windows still doesnt inject NMIs in 64-bit mode either, so i dont think there's any fundamental difference in terms of breakage in the future, it's just that 64-bit systems and 64-bit testing is 1:5 - 1:10 rarer than 32-bit testing. dunno. A distro can still patch the NMI watchdog on, easily. If you think it's a better approach i can make this a .config option - just like CONFIG_DETECT_SOFTLOCKUP: CONFIG_DETECT_HARDLOCKUP, which would default to off? Ingo