Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753173AbYJUJnk (ORCPT ); Tue, 21 Oct 2008 05:43:40 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751277AbYJUJnc (ORCPT ); Tue, 21 Oct 2008 05:43:32 -0400 Received: from one.firstfloor.org ([213.235.205.2]:43459 "EHLO one.firstfloor.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750955AbYJUJnb (ORCPT ); Tue, 21 Oct 2008 05:43:31 -0400 To: akataria@vmware.com Cc: "H. Peter Anvin" , LKML , the arch/x86 maintainers , Dan Hecht Subject: Re: [PATCH 0/3] Improve TSC as a clocksource under VMware From: Andi Kleen References: <1224552902.2640.88.camel@alok-dev1> Date: Tue, 21 Oct 2008 11:43:30 +0200 In-Reply-To: <1224552902.2640.88.camel@alok-dev1> (Alok Kataria's message of "Mon, 20 Oct 2008 18:35:02 -0700") Message-ID: <874p36fflp.fsf@basil.nowhere.org> User-Agent: Gnus/5.1008 (Gnus v5.10.8) Emacs/21.3 (gnu/linux) 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 Content-Length: 899 Lines: 25 Alok Kataria writes: > This patch set makes some changes to the TSC code, so that it is always > used as the default clocksource when running under VMware. Does this imply that vmware always emulates TSC reads? Or how do you guarantee reliable TSC on a system where the underlying TSC isn't? It would be far nicer if VMware just emulated the "constant_tsc" bit in the AMD CPUID leaf, instead of adding all that gunk to Linux. Right now it's only checked for AMD CPUs, but that could be changed. Otherwise with more and more hypervisors we mind end up with more and more unscalable detection code. -Andi -- ak@linux.intel.com -- 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/