Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754627AbYJUSI0 (ORCPT ); Tue, 21 Oct 2008 14:08:26 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751478AbYJUSIR (ORCPT ); Tue, 21 Oct 2008 14:08:17 -0400 Received: from one.firstfloor.org ([213.235.205.2]:37012 "EHLO one.firstfloor.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751423AbYJUSIR (ORCPT ); Tue, 21 Oct 2008 14:08:17 -0400 Date: Tue, 21 Oct 2008 20:15:36 +0200 From: Andi Kleen To: Alok Kataria Cc: Andi Kleen , "H. Peter Anvin" , LKML , the arch/x86 maintainers , Daniel Hecht Subject: Re: [PATCH 0/3] Improve TSC as a clocksource under VMware Message-ID: <20081021181536.GI12825@one.firstfloor.org> References: <1224552902.2640.88.camel@alok-dev1> <874p36fflp.fsf@basil.nowhere.org> <1224607284.6161.22.camel@alok-dev1> <20081021174008.GH12825@one.firstfloor.org> <1224612294.6161.43.camel@alok-dev1> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1224612294.6161.43.camel@alok-dev1> User-Agent: Mutt/1.4.2.1i Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 587 Lines: 15 > FWIU from the code, even if cpu A's TSC is just 1 tick behind that of > cpu B, we increment the nr_wraps value. > And the code expects that there are no wraps in TSC throughout the > 20msec measurement window. > So IMO its fairly easy to fail this test. Ok I think it would be better to enlarge the margin then to fix your issue. -Andi -- 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/