From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754182AbaCJP2h (ORCPT ); Mon, 10 Mar 2014 11:28:37 -0400 Received: from cpsmtpb-ews07.kpnxchange.com ([213.75.39.10]:61064 "EHLO cpsmtpb-ews07.kpnxchange.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753930AbaCJP2g (ORCPT ); Mon, 10 Mar 2014 11:28:36 -0400 Message-ID: <1394465314.12752.18.camel@x220> Subject: Re: [RESEND] Fast TSC calibration fails with v3.14-rc1 and later From: Paul Bolle To: Thomas Gleixner Cc: Julian Wollrath , x86@kernel.org, linux-kernel@vger.kernel.org Date: Mon, 10 Mar 2014 16:28:34 +0100 In-Reply-To: References: <20140310110410.5b2218f6@ilfaris> <1394447253.2979.12.camel@x220> Content-Type: text/plain; charset="UTF-8" X-Mailer: Evolution 3.10.4 (3.10.4-2.fc20) Mime-Version: 1.0 Content-Transfer-Encoding: 7bit X-OriginalArrivalTime: 10 Mar 2014 15:28:34.0753 (UTC) FILETIME=[669E6310:01CF3C75] X-RcptDomain: vger.kernel.org Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, 2014-03-10 at 15:06 +0100, Thomas Gleixner wrote: > And how is this related to Julians observation, that fast calibration > works in 3.13, but stopped to work in 3.14-rc ? In the rest of my message - which you didn't quote - I stated that "the error need not be v3.14-rc1 specific. But perhaps something changed in v3.14-rc1 that makes it easier to trigger that error. I haven't checked". (I didn't add that, in my experience, this message is not seen at every boot.) So I'm basically advising Julian to double check whether this is really a change in behavior between v3.13 and v3.14-rc1. But perhaps Julian already did. And I'm also telling Julian that, as far as I can tell, there's no reason to print this message at KERN_ERR level because what subsequently will happen is that an alternative calibration strategy is tried. So a failure of fast TSC calibration is apparently not so severe. See https://lkml.org/lkml/2012/9/24/221 . Is that analysis incorrect? Thanks, Paul Bolle