Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1030356AbVJEUCR (ORCPT ); Wed, 5 Oct 2005 16:02:17 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1030357AbVJEUCR (ORCPT ); Wed, 5 Oct 2005 16:02:17 -0400 Received: from ebiederm.dsl.xmission.com ([166.70.28.69]:17901 "EHLO ebiederm.dsl.xmission.com") by vger.kernel.org with ESMTP id S1030356AbVJEUCQ (ORCPT ); Wed, 5 Oct 2005 16:02:16 -0400 To: Bill Davidsen Cc: linux-kernel@vger.kernel.org, fastboot@osdl.org Subject: Re: i386 nmi_watchdog: Merge check_nmi_watchdog fixes from x86_64 References: <43442E8E.1090301@tmr.com> From: ebiederm@xmission.com (Eric W. Biederman) Date: Wed, 05 Oct 2005 14:00:48 -0600 In-Reply-To: <43442E8E.1090301@tmr.com> (Bill Davidsen's message of "Wed, 05 Oct 2005 15:50:38 -0400") Message-ID: User-Agent: Gnus/5.1007 (Gnus v5.10.7) Emacs/21.4 (gnu/linux) MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 992 Lines: 22 Bill Davidsen writes: > Eric W. Biederman wrote: >> The per cpu nmi watchdog timer is based on an event counter. idle cpus don't >> generate events so the NMI watchdog doesn't fire >> and the test to see if the watchdog is working fails. > > Question: given all the concern about reducing clocks and all, do we actually > need nmi on more than one CPU? Are there cases where a single CPU hangs in idle > on an SMP system? I really don't know, but the normal interrupt rate is once per second or slower if the cpu is idle. I was just working in the vicinity and discovered when I enabled the nmi watchdog it failed to come on because it didn't handled it's initialization test properly, and x86_64 had already fixed it. Eric - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/