From mboxrd@z Thu Jan 1 00:00:00 1970 From: Gleb Natapov Subject: Re: Linux boot issue: "8254 timer not connected to IO-APIC" Date: Sun, 2 Nov 2008 15:07:12 +0200 Message-ID: <20081102130712.GE16809@redhat.com> References: <490D95FC.3010700@web.de> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: kvm-devel To: Jan Kiszka Return-path: Received: from mx2.redhat.com ([66.187.237.31]:44384 "EHLO mx2.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753857AbYKBNHQ (ORCPT ); Sun, 2 Nov 2008 08:07:16 -0500 Content-Disposition: inline In-Reply-To: <490D95FC.3010700@web.de> Sender: kvm-owner@vger.kernel.org List-ID: On Sun, Nov 02, 2008 at 12:58:52PM +0100, Jan Kiszka wrote: > Hi, > > from time to time Linux fails to boot in my kvm boxes, complaining like > this: > > [...] > PAT WC disabled due to known CPU erratum. > CPU: L1 I cache: 32K, L1 D cache: 32K > CPU: L2 cache: 2048K > CPU 0/0 -> Node 0 > ACPI: Core revision 20080609 > Parsing all Control Methods: > Table [DSDT](id 0001) - 295 Objects with 45 Devices 104 Methods 6 Regions > tbxface-0596 [00] tb_load_namespace : ACPI Tables successfully acquired > evxfevnt-0091 [00] enable : Transition to ACPI mode successful > ..TIMER: vector=0x30 apic1=0 pin1=0 apic2=-1 pin2=-1 > ..MP-BIOS bug: 8254 timer not connected to IO-APIC > ...trying to set up timer (IRQ0) through the 8259A ... > ..... (found apic 0 pin 0) ... > ....... failed. > timer doesn't work through the IO-APIC - disabling NMI Watchdog! > ...trying to set up timer as Virtual Wire IRQ... > ..... failed. > ...trying to set up timer as ExtINT IRQ... > ..... failed :(. > Kernel panic - not syncing: IO-APIC + timer doesn't work! Boot with apic=debug and send a report. Then try booting with the 'noapic' option. > > The problem seems to be that timer_irq_works() fails, ie. less than 4 > out of 10 PIC ticks made it to the guest within that test window. Gleb, > is this something your anti-drift patches for the PIC would address as > well? > If the problem is indeed interrupt coalescing then anti-drift patches will help. -- Gleb.