From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id ; Fri, 25 Oct 2002 13:56:23 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id ; Fri, 25 Oct 2002 13:56:23 -0400 Received: from harpo.it.uu.se ([130.238.12.34]:28880 "EHLO harpo.it.uu.se") by vger.kernel.org with ESMTP id ; Fri, 25 Oct 2002 13:56:22 -0400 Date: Fri, 25 Oct 2002 20:02:36 +0200 (MET DST) From: Mikael Pettersson Message-Id: <200210251802.UAA18166@harpo.it.uu.se> To: linux-kernel@vger.kernel.org, minyard@acm.org Subject: Re: NMI watchdog not ticking at the right intervals Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Fri, 25 Oct 2002 09:09:10 -0500, Corey Minyard wrote: >As I have been working on my NMI patch, I have noticed that the NMI >watchdog does not seem to be ticking correctly. I've tried 2.4 and 2.5 >kernels, and I get the same results. From my reading of the code, it >should tick once a second. However, I have had the time between ticks >vary from around 33 to over 100 seconds. Tbe time between ticks is >different on every boot, but is consistent once booted. Is there some >divider register that's not getting initialized? > >Here's my cpuinfo: > >processor : 0 >cpu_package : 0 >vendor_id : GenuineIntel >cpu family : 6 >model : 11 >model name : Intel(R) Pentium(R) III Mobile CPU 1066MHz (Me thinks "speedstep?") Do you boot with nmi_watchdog=1 or 2? The perfctr + local-APIC driven NMI watchdog is dependent on the CPU's clock frequency. If this changes, the NMI rate will change accordingly. The NMI rate may also be affected by APM/ACPI and how often the kernel executes HLT. /Mikael