From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1760048AbXEMVdE (ORCPT ); Sun, 13 May 2007 17:33:04 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1755554AbXEMVc4 (ORCPT ); Sun, 13 May 2007 17:32:56 -0400 Received: from aun.it.uu.se ([130.238.12.36]:43031 "EHLO aun.it.uu.se" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755457AbXEMVcz (ORCPT ); Sun, 13 May 2007 17:32:55 -0400 Date: Sun, 13 May 2007 23:30:56 +0200 (MEST) Message-Id: <200705132130.l4DLUu86011130@harpo.it.uu.se> From: Mikael Pettersson To: johnstul@us.ibm.com, mikpe@it.uu.se Subject: Re: Fw: [BUG 2.6.21-rc7] acpi_pm clocksource loses time on x86-64 Cc: ak@suse.de, lenb@kernel.org, linux-kernel@vger.kernel.org, tglx@linutronix.de Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Thu, 10 May 2007 11:52:33 -0700, john stultz wrote: > On Wed, 2007-05-09 at 11:11 +0200, Mikael Pettersson wrote: > > On Tue, 8 May 2007 15:14:36 -0400, Len Brown wrote: > > > On Friday 04 May 2007 03:42, Mikael Pettersson wrote: > > > > On Thu, 03 May 2007 19:38:50 -0700, john stultz wrote: > > > > > > So that slow acpi_pm on x86_64 seems to be connected w/ the idle loop. > > > > > > I'm guessing the chipset halts the ACPI PM in lower C states. Do you > > > > > > have any guesses as to what might differ between x86_64 and i386 ACPI > > > > > > idle loops? Or might this be something different in what the BIOS > > > > > > exports in x86_64 mode or i386 mode? > > > > > > > > > > Mikael, > > > > > Just trying to dig a bit more through the acpi_processor_idle code. > > > > > Could you run "cat /proc/acpi/processor/CPU1/power" and reply w/ the > > > > > output? > > > > > > > > Here's that file with the x86-64 kernel: > > > > > > > > active state: C2 > > > > max_cstate: C8 > > > > bus master activity: 00000000 > > > > maximum allowed latency: 20000 usec > > > > states: > > > > C1: type[C1] promotion[C2] demotion[--] latency[000] usage[00107840] duration[00000000000000000000] > > > > *C2: type[C2] promotion[--] demotion[C1] latency[010] usage[-1987043693] duration[00000000003044809185] > > > > > > it may be that the problem is C2, not C1 on this box and thus "idle=poll" may be > > > overkill to workaround it. > > > > > > You can disable C2 with "processor.max_cstate=1" > > Hey Mikael, > Did booting w/ processor.max_cstate=1 have the same effect as booting > w/ idle=poll ? It seems so. `/sbin/hwclock' and `date' are still in sync after 60 minutes, where previously `date' would lag behind by about 3 minutes. /Mikael