From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753156AbZBEUje (ORCPT ); Thu, 5 Feb 2009 15:39:34 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752712AbZBEUjV (ORCPT ); Thu, 5 Feb 2009 15:39:21 -0500 Received: from mail.candelatech.com ([208.74.158.172]:54687 "EHLO ns3.lanforge.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752685AbZBEUjT (ORCPT ); Thu, 5 Feb 2009 15:39:19 -0500 Message-ID: <498B4E44.9080607@candelatech.com> Date: Thu, 05 Feb 2009 12:38:28 -0800 From: Ben Greear Organization: Candela Technologies User-Agent: Thunderbird 1.5.0.12 (X11/20070530) MIME-Version: 1.0 To: Ingo Molnar CC: Thomas Gleixner , "H. Peter Anvin" , Yinghai Lu , linux-kernel , rusty@rustcorp.com.au Subject: Re: PATCH: Allow user to force 'tsc' to be treated as stable. References: <498B42C5.7010905@candelatech.com> <20090205195945.GE3129@elte.hu> In-Reply-To: <20090205195945.GE3129@elte.hu> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Ingo Molnar wrote: > * Ben Greear wrote: > >> Allow user to force TSC as stable clock-source. >> Works around BIOS issues in the FWA-7304 (Via CN700 chipset) >> system, and possibly others. >> >> This is against 2.6.29-rc3. > > What 'issues' does that work around, exactly? Without this, my system comes up with no stable high-res clock, and the getnstimeofday seems to return something with around 1ms granularity. I have HZ set to 1000, so its probably just using the 'jiffy' clocksource. This in turn screws up my patched version of pktgen and likely is sub-optimal for other things as well. It seems the TSC on this system is stable, but I got lost trying to understand the watchdog testing code, so I'm not certain if it is wrong or not. With this force in place, the system seems stable and ran overnight under network load fine. Also, the BIOS on my system seems quite bad about filling out tables, so that may be part of the root cause. Thanks, Ben > > Ingo > -- > 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/ -- Ben Greear Candela Technologies Inc http://www.candelatech.com