From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1422673AbXBURVM (ORCPT ); Wed, 21 Feb 2007 12:21:12 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1422717AbXBURVM (ORCPT ); Wed, 21 Feb 2007 12:21:12 -0500 Received: from gateway-1237.mvista.com ([63.81.120.158]:3150 "EHLO gateway-1237.mvista.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1422673AbXBURVL (ORCPT ); Wed, 21 Feb 2007 12:21:11 -0500 Subject: Re: Linux 2.6.21-rc1 From: Daniel Walker To: tglx@linutronix.de Cc: Linus Torvalds , Linux Kernel Mailing List , mingo@elte.hu In-Reply-To: <1172077664.25076.75.camel@localhost.localdomain> References: <1172075053.8577.38.camel@imap.mvista.com> <1172077664.25076.75.camel@localhost.localdomain> Content-Type: text/plain Date: Wed, 21 Feb 2007 09:19:00 -0800 Message-Id: <1172078340.8577.43.camel@imap.mvista.com> Mime-Version: 1.0 X-Mailer: Evolution 2.8.2.1 (2.8.2.1-3.fc6) Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Wed, 2007-02-21 at 18:07 +0100, Thomas Gleixner wrote: > On Wed, 2007-02-21 at 08:24 -0800, Daniel Walker wrote: > > > The most interesting core change may be the dyntick/nohz one, where timer > > > ticks will only happen when needed. It's been brewing for a _loong_ time, > > > but it's in the standard kernel now as an option. > > > > On i386 I get the following, > > > > TCP cubic registered > > NET: Registered protocol family 1 > > NET: Registered protocol family 17 > > Testing NMI watchdog ... CPU#0: NMI appears to be stuck (24->24)! > > CPU#1: NMI appears to be stuck (0->0)! > > CPU#2: NMI appears to be stuck (0->0)! > > CPU#3: NMI appears to be stuck (0->0)! > > > > when I add nmi_watchdog=1 to my boot args which worked on prior kernels. > > On closer inspection it looks like arch/i386/kernel/io_apic.c : > > check_timer() --> timer_irq_works() depends on IRQ0 incrementing jiffies > > which is no longer the case AFAIK. > > At this point the PIT / HPET _is_ active and incrementing jiffies. The > switch to local apic timers happens afterwards. Could be the switch over then which confuses the NMI . > > I'm not sure exactly how that relates to the NMI, but the check_timer() > > function disabled the NMI through the io-apic if it can't get the > > "timer" working through the io-apic. > > Boot log please. > > tglx > .config is in there too . ftp://source.mvista.com/pub/dwalker/tglx/