From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755950AbYEHLrP (ORCPT ); Thu, 8 May 2008 07:47:15 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1750933AbYEHLq7 (ORCPT ); Thu, 8 May 2008 07:46:59 -0400 Received: from www.tglx.de ([62.245.132.106]:55004 "EHLO www.tglx.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750800AbYEHLq6 (ORCPT ); Thu, 8 May 2008 07:46:58 -0400 Date: Thu, 8 May 2008 13:46:38 +0200 (CEST) From: Thomas Gleixner To: Philipp Kohlbecher cc: linux-kernel@vger.kernel.org, John Stultz Subject: Re: clocksources: order of preference In-Reply-To: <4822DF0B.8080109@gmx.de> Message-ID: References: <4822D8B6.4090008@gmx.de> <4822DF0B.8080109@gmx.de> User-Agent: Alpine 1.10 (LFD 962 2008-03-14) MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, 8 May 2008, Philipp Kohlbecher wrote: > Thomas Gleixner wrote: > > We also check the TSC with a watchdog mechanism, which verifies that > > is is keeping accurate time. When we detect that TSC does not, we > > replace it by the next available clock source. > > > True. In all the cases I know, the watchdog mechanism worked and marked the > TSC as unstable. The soft lockup only led to a (sometimes considerable) delay > at boot time. Yeah, there are some hard to detect cases. This TSC business is a major PITA. Thanks, tglx