Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S261640AbVEJNc4 (ORCPT ); Tue, 10 May 2005 09:32:56 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S261644AbVEJNc4 (ORCPT ); Tue, 10 May 2005 09:32:56 -0400 Received: from cantor2.suse.de ([195.135.220.15]:164 "EHLO mx2.suse.de") by vger.kernel.org with ESMTP id S261640AbVEJNcv (ORCPT ); Tue, 10 May 2005 09:32:51 -0400 Date: Tue, 10 May 2005 15:32:50 +0200 From: Andi Kleen To: Ed Tomlinson Cc: Bernd Paysan , suse-amd64@suse.com, Andi Kleen , linux-kernel@vger.kernel.org Subject: Re: [suse-amd64] False "lost ticks" on dual-Opteron system (=> timer twice as fast) Message-ID: <20050510133250.GK25612@wotan.suse.de> References: <200505081445.26663.bernd.paysan@gmx.de> <200505091253.21252.bernd.paysan@gmx.de> <200505091517.30555.bernd.paysan@gmx.de> <200505100653.50775.tomlins@cam.org> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <200505100653.50775.tomlins@cam.org> Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1580 Lines: 35 On Tue, May 10, 2005 at 06:53:49AM -0400, Ed Tomlinson wrote: > Maybe on UP too: > > May 8 18:50:25 grover kernel: [143640.507170] Attached scsi removable disk sda at scsi5, channel 0, id 0, lun 0 > May 8 18:50:25 grover kernel: [143640.520422] rtc: lost some interrupts at 1024Hz. > May 8 18:50:25 grover kernel: [143640.554134] Attached scsi generic sg0 at scsi5, channel 0, id 0, lun 0, type 0 > May 8 18:50:25 grover kernel: [143640.567693] rtc: lost some interrupts at 1024Hz. > May 8 18:50:25 grover kernel: [143640.596402] usb-storage: device scan complete > > This from 12-rc3-mm3, UP x86_64 with powernow active. More likely it is some driver hogging interrupts (turning them off for too long). You can boot with report_lost_ticks, then the normal timer interrupt will complain. Note it always triggers at boot a few times. When you find the culprit report it to the driver driver maintainer. > > It might be that the message is OK here since I do not see a fast clock. I mention this > since powernow is active here. > > Should HPET be available in UP? HPET is used on HPET only as the backing clock and to run the timer interrupt, but not for gettimeofday because using the TSC is considerable faster there. Actually the actual strategy is bit more complicated, it also depends on some other things. -Andi - 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/