Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1423035AbXBUXTn (ORCPT ); Wed, 21 Feb 2007 18:19:43 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1423248AbXBUXTn (ORCPT ); Wed, 21 Feb 2007 18:19:43 -0500 Received: from an-out-0708.google.com ([209.85.132.249]:5817 "EHLO an-out-0708.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1423035AbXBUXTm (ORCPT ); Wed, 21 Feb 2007 18:19:42 -0500 DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=beta; h=received:message-id:date:from:to:subject:cc:in-reply-to:mime-version:content-type:content-transfer-encoding:content-disposition:references; b=LLRVATNHH601DEe6OioVSE7T6ON68YIqGt1CUfta7fV94A1NpXGNlodaryj52w0uJapa+usw08fbD/xlpE7CPXa1sAr1hxgLW4/dgDoOAZYiaEaccYbQ2065PF696LpYyubTCRSq4ZdBez/Q+81VLGAprSOcw4uCyrtBNJ2ArZY= Message-ID: <68676e00702211519k68104e31ia2ae38a14eb27c1f@mail.gmail.com> Date: Thu, 22 Feb 2007 00:19:41 +0100 From: "Luca Tettamanti" To: tglx@linutronix.de Subject: Re: NO_HZ: timer interrupt stuck [Re: Linux 2.6.21-rc1] Cc: linux-kernel@vger.kernel.org In-Reply-To: <1172099859.25076.132.camel@localhost.localdomain> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Content-Disposition: inline References: <20070221230409.GA1158@dreamland.darkstar.lan> <1172099859.25076.132.camel@localhost.localdomain> Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2070 Lines: 45 On 2/22/07, Thomas Gleixner wrote: > On Thu, 2007-02-22 at 00:04 +0100, Luca Tettamanti wrote: > > Hi Thomas, > > I'm testing NO_HZ on my machines. On the laptop I see that the timer > > interrupt counter is incremented (though slower than HZ). This machine > > is running UP kernel. > > > > On my desktop I see this: > > > > CPU0 CPU1 > > 0: 114 0 IO-APIC-edge timer > > 1: 1624 10771 IO-APIC-edge i8042 > > 6: 3 0 IO-APIC-edge floppy > > 7: 0 0 IO-APIC-edge parport0 > > 9: 0 0 IO-APIC-fasteoi acpi > > 12: 40111 184047 IO-APIC-edge i8042 > > 16: 75624 998858 IO-APIC-fasteoi radeon@pci:0000:01:00.0, uhci_hcd:usb1 > > 17: 0 0 IO-APIC-fasteoi uhci_hcd:usb4 > > 18: 711 5487 IO-APIC-fasteoi ide1, libata, ehci_hcd:usb7, uhci_hcd:usb3 > > 19: 617 2254 IO-APIC-fasteoi libata, uhci_hcd:usb2 > > 20: 0 0 IO-APIC-fasteoi ehci_hcd:usb6, uhci_hcd:usb5 > > 21: 2483869 0 IO-APIC-fasteoi eth0 > > 22: 2 0 IO-APIC-fasteoi ohci1394 > > 218: 28872 360643 PCI-MSI-edge HDA Intel > > 219: 32932 138196 PCI-MSI-edge libata > > NMI: 0 0 > > LOC: 2761191 2827539 > > ERR: 0 > > MIS: 0 > > > > Interrupt 0 is stuck at 114 (the number is consistent across reboots). I > > don't experience any problem, time is running fine. Still it's strange > > that the timer is doing nothing; maybe something other than the PIT is > > used for time keeping? > > Yes, we switch away from PIT and use the local APIC timer. (LOC) Ok, thanks for the clarification. Luca - 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/