From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S272290AbTG3WxJ (ORCPT ); Wed, 30 Jul 2003 18:53:09 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S272300AbTG3WxJ (ORCPT ); Wed, 30 Jul 2003 18:53:09 -0400 Received: from meryl.it.uu.se ([130.238.12.42]:63431 "EHLO meryl.it.uu.se") by vger.kernel.org with ESMTP id S272290AbTG3WxF (ORCPT ); Wed, 30 Jul 2003 18:53:05 -0400 Date: Thu, 31 Jul 2003 00:53:00 +0200 (MEST) Message-Id: <200307302253.h6UMr0XW024175@harpo.it.uu.se> From: Mikael Pettersson To: vherva@niksula.hut.fi Subject: Re: [PATCH] NMI watchdog documentation Cc: ak@suse.de, linux-kernel@vger.kernel.org Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Wed, 30 Jul 2003 22:40:52 +0300, Ville Herva wrote: >Ok, you got me confused (thankfully I didn't submit anything for inclusion >yet. :) ... >So... Should it be something like: > >+For x86-64, the needed APIC is always compiled in, and the NMI watchdog is >+always enabled with perctr mode. Currently, mode=2 (local APIC) does not always enabled with I/O-APIC mode. >+work on x86-64. IO APIC mode (mode=1) is the default. Using NMI watchdog Using local APIC >+(mode=1) needs the first performance register, so you can't use it for (mode=2) >+other purposes (such as high precision performance profiling.) >(Is the last sentence only valid for x86-64?) No, it's true for both x86 and x86-64. However, both oprofile and the perfctr driver disable the local APIC NMI watchdog, so the statement is only true for other drivers that don't do this. /Mikael