Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1750872AbVJHKMY (ORCPT ); Sat, 8 Oct 2005 06:12:24 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1750891AbVJHKMY (ORCPT ); Sat, 8 Oct 2005 06:12:24 -0400 Received: from tentacle.b.gz.ru ([217.67.124.4]:31367 "EHLO tentacle.sectorb.msk.ru") by vger.kernel.org with ESMTP id S1750862AbVJHKMY (ORCPT ); Sat, 8 Oct 2005 06:12:24 -0400 Date: Sat, 8 Oct 2005 14:11:53 +0400 From: "Vladimir B. Savkin" To: Andi Kleen Cc: lkml , Andrew Morton , john stultz , discuss@x86-64.org Subject: Re: [PATCH] x86-64: Fix bad assumption that dualcore cpus have synced TSCs Message-ID: <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> Mime-Version: 1.0 Content-Type: text/plain; charset=koi8-r Content-Disposition: inline In-Reply-To: <200510071431.47245.ak@suse.de> X-Organization: Moscow State Univ., Institute of Mechanics X-Operating-System: Linux 2.6.11-ac7 User-Agent: Mutt/1.5.9i Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2022 Lines: 54 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. > > > > Please consider for inclusion in your tree. > > > > > > thanks > > > -john > > > > > > diff --git a/arch/x86_64/kernel/time.c b/arch/x86_64/kernel/time.c > > > --- a/arch/x86_64/kernel/time.c > > > +++ b/arch/x86_64/kernel/time.c > > > @@ -959,9 +959,6 @@ static __init int unsynchronized_tsc(voi > > > are handled in the OEM check above. */ > > > if (boot_cpu_data.x86_vendor == X86_VENDOR_INTEL) > > > return 0; > > > - /* All in a single socket - should be synchronized */ > > > - if (cpus_weight(cpu_core_map[0]) == num_online_cpus()) > > > - return 0; > > > #endif > > > /* Assume multi socket systems are not synchronized */ > > > return num_online_cpus() > 1; > > > > ~ ~ :wq With best regards, Vladimir Savkin. - 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/