From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S271380AbTG2Khz (ORCPT ); Tue, 29 Jul 2003 06:37:55 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S271383AbTG2Khz (ORCPT ); Tue, 29 Jul 2003 06:37:55 -0400 Received: from meryl.it.uu.se ([130.238.12.42]:17852 "EHLO meryl.it.uu.se") by vger.kernel.org with ESMTP id S271380AbTG2Khy (ORCPT ); Tue, 29 Jul 2003 06:37:54 -0400 Date: Tue, 29 Jul 2003 12:37:33 +0200 (MEST) Message-Id: <200307291037.h6TAbX9G026932@harpo.it.uu.se> From: Mikael Pettersson To: ak@suse.de, vherva@niksula.hut.fi Subject: Re: [PATCH] NMI watchdog documentation Cc: linux-kernel@vger.kernel.org, marcelo@conectiva.com.br, torvalds@osdl.org Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Mon, 28 Jul 2003 19:53:42 +0200, Andi Kleen wrote: >On Wed, 23 Jul 2003 20:43:25 +0300 >Ville Herva wrote: > >> Documentation/nmi-watchdoc.txt doesn't actually tell what options need to be >> enabled in kernel config in order to use NMI watchdog. I for one found it >> confusing. >> >> I vaguely recall someone posted a similar patch some time ago, but it still >> doesn't seem to be present in 2.4 or 2.6-test. >> >> Andi: what about x86-64 - does it have something similar that should be >> mentioned? > >x86-64 is the same, except APIC is always compiled in and the nmi watchdog is >always enabled with perfctr mode. mode=2 seems to also not work correctly currently. > >However one caveat (even for i386): when you use perfctr mode 1 you lose the first >performance register which you may need for other things. Andi, you have the numbers mixed up. mode 1 is I/O-APIC, mode 2 is local APIC, and x86-64 defaults nmi_watchdog to I/O-APIC mode. Now, is it the I/O-APIC or local APIC watchdog that doesn't work in x86-64? /Mikael