Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751129AbVJJSDf (ORCPT ); Mon, 10 Oct 2005 14:03:35 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751130AbVJJSDf (ORCPT ); Mon, 10 Oct 2005 14:03:35 -0400 Received: from e33.co.us.ibm.com ([32.97.110.151]:49835 "EHLO e33.co.us.ibm.com") by vger.kernel.org with ESMTP id S1751129AbVJJSDe (ORCPT ); Mon, 10 Oct 2005 14:03:34 -0400 Subject: Re: [PATCH] x86-64: Fix bad assumption that dualcore cpus have synced TSCs From: john stultz To: "Vladimir B. Savkin" Cc: Andi Kleen , lkml , Andrew Morton , discuss@x86-64.org In-Reply-To: <20051008101153.GA1541@tentacle.sectorb.msk.ru> References: <1127157404.3455.209.camel@cog.beaverton.ibm.com> <20051007122624.GA23606@tentacle.sectorb.msk.ru> <200510071431.47245.ak@suse.de> <20051008101153.GA1541@tentacle.sectorb.msk.ru> Content-Type: text/plain Date: Mon, 10 Oct 2005 11:03:24 -0700 Message-Id: <1128967404.8195.419.camel@cog.beaverton.ibm.com> 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: 1669 Lines: 42 On Sat, 2005-10-08 at 14:11 +0400, Vladimir B. Savkin wrote: > On Fri, Oct 07, 2005 at 02:31:46PM +0200, Andi Kleen wrote: > > On Friday 07 October 2005 14:26, Vladimir B. Savkin wrote: > > > On Mon, Sep 19, 2005 at 12:16:43PM -0700, john stultz wrote: > > > > Andrew, > > > > This patch should resolve the issue seen in bugme bug #5105, where it > > > > is assumed that dualcore x86_64 systems have synced TSCs. This is not > > > > the case, and alternate timesources should be used instead. > > > > > > > > For more details, see: > > > > http://bugzilla.kernel.org/show_bug.cgi?id=5105 > > > > > > I too have a box that shows the symptoms from bugzilla entry above. > > > The system is Asus A8V Deluxe MB with > > > "AMD Athlon(tm) 64 X2 Dual Core Processor 3800+". > > > > > > The patch below did not fix the problem, while "idle=poll" did. > > > Hope this helps, dmesg attached. > > > > Are you running the latest BIOS? > > Just upgraded to the lastest BIOS (revision 1014), nothing changed. > Only with "idle=poll" timers run normally. >From your dmesg, it appears that there are no other timesources other then the TSC available on your hardware. So I'm guessing idle=poll is keeping the CPUs from halting the TSC and keeping them synched. I would think that the ACPI PM timer would be supported, but I don't see anything about it in your dmesg. Could you make sure it is properly configured in? 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/