From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753257AbZBEVC7 (ORCPT ); Thu, 5 Feb 2009 16:02:59 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752268AbZBEVCu (ORCPT ); Thu, 5 Feb 2009 16:02:50 -0500 Received: from mx3.mail.elte.hu ([157.181.1.138]:53615 "EHLO mx3.mail.elte.hu" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752115AbZBEVCu (ORCPT ); Thu, 5 Feb 2009 16:02:50 -0500 Date: Thu, 5 Feb 2009 22:02:39 +0100 From: Ingo Molnar To: Ben Greear 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. Message-ID: <20090205210239.GD21500@elte.hu> References: <498B42C5.7010905@candelatech.com> <20090205195945.GE3129@elte.hu> <498B4E44.9080607@candelatech.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <498B4E44.9080607@candelatech.com> User-Agent: Mutt/1.5.18 (2008-05-17) X-ELTE-VirusStatus: clean X-ELTE-SpamScore: -1.5 X-ELTE-SpamLevel: X-ELTE-SpamCheck: no X-ELTE-SpamVersion: ELTE 2.0 X-ELTE-SpamCheck-Details: score=-1.5 required=5.9 tests=BAYES_00 autolearn=no SpamAssassin version=3.2.3 -1.5 BAYES_00 BODY: Bayesian spam probability is 0 to 1% [score: 0.0000] Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org * Ben Greear wrote: > 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. What does this tool output: http://people.redhat.com/mingo/time-warp-test/time-warp-test.c ? (you can run it both the patched or on the unpatched system) Ingo