Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1422767AbXBUSZc (ORCPT ); Wed, 21 Feb 2007 13:25:32 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1422768AbXBUSZc (ORCPT ); Wed, 21 Feb 2007 13:25:32 -0500 Received: from gateway-1237.mvista.com ([63.81.120.158]:21023 "EHLO gateway-1237.mvista.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1422767AbXBUSZb (ORCPT ); Wed, 21 Feb 2007 13:25:31 -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: <1172081931.25076.95.camel@localhost.localdomain> References: <1172075053.8577.38.camel@imap.mvista.com> <1172077664.25076.75.camel@localhost.localdomain> <1172078340.8577.43.camel@imap.mvista.com> <1172079671.25076.80.camel@localhost.localdomain> <1172079523.8577.48.camel@imap.mvista.com> <1172081931.25076.95.camel@localhost.localdomain> Content-Type: text/plain Date: Wed, 21 Feb 2007 10:23:20 -0800 Message-Id: <1172082200.8577.56.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 Content-Length: 1910 Lines: 56 On Wed, 2007-02-21 at 19:18 +0100, Thomas Gleixner wrote: > On Wed, 2007-02-21 at 09:38 -0800, Daniel Walker wrote: > > > > > > > > Could be the switch over then which confuses the NMI . > > > > > > Why? The switch just stops the PIT/HPET. It does not fiddle with IO_APIC > > > and friends at all. > > > > I'm not an expert on the io-apic, but the check_timer() function seemed > > to assume IRQ0 was happening regularly .. > > Again: > > check_timer() is called _BEFORE_ we even touch the local APIC timers. At > this point PIT/HPET _IS_ firing IRQ0 with HZ frequency. Right, but eventually there isn't a regular timer interrupt through the io-apic. I don't think in the past IRQ0 stops without the system crashing, so check_timer() could assume the timer (IRQ0) is _always_ regular. do you know what the requirement are for routing the NMI through the io-apic? > > Well, I'm pretty sure it's HRT, cause in prior versions this only > > happened when HRT is enabled. Then you guys went to the lapic all the > > time, and now this is happening all the time .. > > The NMI is stuck: > > if (nmi_count(cpu) - prev_nmi_count[cpu] <= 5) { > printk("CPU#%d: NMI appears to be stuck (%d->%d)!\n", > cpu, > prev_nmi_count[cpu], > nmi_count(cpu)); > > This has nothing to do with jiffies. I think it has to do with IRQ0 . Did I mention this doesn't happen in 2.6.20 . > There have been a bunch of changes in arch/i386/kernel/nmi.c as well. > > > You can't reproduce this? > > Nope. Do you use nmi_watchdog=1 ? Daniel - 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/