Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932077AbVKOVFY (ORCPT ); Tue, 15 Nov 2005 16:05:24 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S932093AbVKOVFY (ORCPT ); Tue, 15 Nov 2005 16:05:24 -0500 Received: from e31.co.us.ibm.com ([32.97.110.149]:16054 "EHLO e31.co.us.ibm.com") by vger.kernel.org with ESMTP id S932077AbVKOVFW (ORCPT ); Tue, 15 Nov 2005 16:05:22 -0500 Subject: Re: [PATCH 0/13] Time: Generic Timeofday Subsystem (v B10) From: john stultz To: Ingo Molnar Cc: Frank Sorenson , lkml , Darren Hart , Nishanth Aravamudan , George Anzinger , Roman Zippel , Ulrich Windl , Thomas Gleixner In-Reply-To: <20051115205355.GA20885@elte.hu> References: <20051112044850.8240.91581.sendpatchset@cog.beaverton.ibm.com> <4378FFFF.4010706@tuxrocks.com> <1132004327.4668.30.camel@leatherman> <4379074D.5060308@tuxrocks.com> <1132005736.4668.34.camel@leatherman> <437918A0.8000308@tuxrocks.com> <1132010724.4668.40.camel@leatherman> <43796C76.8070603@tuxrocks.com> <1132084415.2906.12.camel@leatherman> <20051115205355.GA20885@elte.hu> Content-Type: text/plain Date: Tue, 15 Nov 2005 13:04:45 -0800 Message-Id: <1132088686.2906.16.camel@leatherman> Mime-Version: 1.0 X-Mailer: Evolution 2.2.3 (2.2.3-2.fc4) Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1768 Lines: 43 On Tue, 2005-11-15 at 21:53 +0100, Ingo Molnar wrote: > * john stultz wrote: > > > > idle=poll does seem to fix the major clock drift problem. There may > > > still be an issue, but it's much smaller: > > > > > > 2.6.14-mm2-todb10: > > > 14 Nov 21:50:57 offset: -0.025373 drift: -22404.0 ppm > > > 14 Nov 21:51:59 offset: -1.577053 drift: -24985.4603175 ppm > > > 14 Nov 21:53:00 offset: -3.104569 drift: -25012.9032258 ppm > > > > > > 2.6.14-mm2-todb10 with idle=poll: > > > 14 Nov 21:37:59 offset: 5.9e-05 drift: 63.0 ppm > > > 14 Nov 21:39:00 offset: 0.003207 drift: 51.7903225806 ppm > > > > Hmm. It seems the c3 compensation is triggering when it shouldn't, or > > maybe its over compensating. > > > > I can't reproduce it on my laptop. Do you recall if in previous tests > > you saw anything like this? I'm trying to narrow down if its just a > > difference in hardware or if something in the c3 idle code changed. > > it's with an earlier queue of yours, but maybe it's related: i have a > report that HPET causes HRT inaccuracies (e.g. sleeps for 20 msecs last > 21 msecs). If all HPET options are turned off in the .config then > everything is fine and accurate. Hmm. HPET would be separate from this, I believe. I suspect that could be related to the HPET legacy replacement functionality, where the HPET is triggering the timer interrupts. Not something I changed, but probably should be looked into. thanks -john - 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/