From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756200AbZBTE6A (ORCPT ); Thu, 19 Feb 2009 23:58:00 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752479AbZBTE5w (ORCPT ); Thu, 19 Feb 2009 23:57:52 -0500 Received: from byss.tchmachines.com ([208.76.80.75]:56025 "EHLO byss.tchmachines.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751697AbZBTE5v (ORCPT ); Thu, 19 Feb 2009 23:57:51 -0500 Date: Thu, 19 Feb 2009 20:57:49 -0800 From: Josh Hunt To: tglx@linutronix.de Cc: linux-kernel@vger.kernel.org, kiran@scalex86.org Subject: Clocksource with rating 0 marked unstable twice Message-ID: <20090220045749.GC8151@localhost.localdomain> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline User-Agent: Mutt/1.5.18 (2008-05-17) X-AntiAbuse: This header was added to track abuse, please include it with any abuse report X-AntiAbuse: Primary Hostname - byss.tchmachines.com X-AntiAbuse: Original Domain - vger.kernel.org X-AntiAbuse: Originator/Caller UID/GID - [47 12] / [47 12] X-AntiAbuse: Sender Address Domain - scalex86.org Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org I have a system with TSCs which are known to be unsynchronized. During TSC initialization it is marked as unstable, but later on in the boot the clocksource watchdog code also marks it unstable. This seems a bit redundant as both set the rating to 0. [ 0.000000] Marking TSC unstable due to TSCs unsynchronized ... [ 4.740022] Clocksource tsc unstable (delta = 4380394573887 ns) I can think of two solutions, both modifying clocksource_register when rating is 0: 1. Do not call clocksource_check_watchdog. This way the clocksource is not put on the watchdog list. 2. Do not enqueue the clocksource or do any registering. Is there a good reason to keep around a clocksource which has a rating of 0? Which of these would be better? I can provide a patch for either. Thanks Josh