Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1947213AbWKKNzp (ORCPT ); Sat, 11 Nov 2006 08:55:45 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1754487AbWKKNzp (ORCPT ); Sat, 11 Nov 2006 08:55:45 -0500 Received: from www.osadl.org ([213.239.205.134]:9951 "EHLO mail.tglx.de") by vger.kernel.org with ESMTP id S1754483AbWKKNzo (ORCPT ); Sat, 11 Nov 2006 08:55:44 -0500 Subject: Re: [patch 13/19] GTOD: Mark TSC unusable for highres timers From: Thomas Gleixner Reply-To: tglx@linutronix.de To: Andi Kleen Cc: Andrew Morton , Ingo Molnar , john stultz , LKML , Len Brown , Arjan van de Ven , Roman Zippel In-Reply-To: <200611111451.33511.ak@suse.de> References: <20061109233030.915859000@cruncher.tec.linutronix.de> <200611101029.59251.ak@suse.de> <1163243677.8335.245.camel@localhost.localdomain> <200611111451.33511.ak@suse.de> Content-Type: text/plain Date: Sat, 11 Nov 2006 14:58:08 +0100 Message-Id: <1163253488.8335.247.camel@localhost.localdomain> Mime-Version: 1.0 X-Mailer: Evolution 2.6.1 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1151 Lines: 28 On Sat, 2006-11-11 at 14:51 +0100, Andi Kleen wrote: > > > > And afaict the reason for that is that we're using jiffies to determine if > > > > the TSC has gone bad, and that test is getting false positives. > > > > > > The i386 clocksource had always trouble with that. e.g. I have a box > > > where the TSC works perfectly fine on a 64bit kernel, but since the new i386 > > > clocksource code is in it always insists on disabling it shortly after boot. > > shortly after boot means in user space here, not during the first idling. > > > > My guess is that some of the checks in there are just broken and need > > > to be fixed. > > > > It's the unconditional mark_unstable call in ACPI C2 state. /me looks. > > The system doesn't support C2 states. It's an older single socket Athlon 64 > with VIA chipset. I haven't looked in detail on why it fails. Does it have cpu freqency changing ? tglx - 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/