Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756291Ab0D0S55 (ORCPT ); Tue, 27 Apr 2010 14:57:57 -0400 Received: from mx1.redhat.com ([209.132.183.28]:7800 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755683Ab0D0S54 (ORCPT ); Tue, 27 Apr 2010 14:57:56 -0400 Date: Tue, 27 Apr 2010 15:57:53 -0300 From: Glauber Costa To: Avi Kivity Cc: Marcelo Tosatti , kvm@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH 6/6] don't compute pvclock adjustments if we trust the tsc Message-ID: <20100427185753.GR16166@mothafucka.localdomain> References: <1272303988-21929-1-git-send-email-glommer@redhat.com> <1272303988-21929-2-git-send-email-glommer@redhat.com> <1272303988-21929-3-git-send-email-glommer@redhat.com> <1272303988-21929-4-git-send-email-glommer@redhat.com> <1272303988-21929-5-git-send-email-glommer@redhat.com> <1272303988-21929-6-git-send-email-glommer@redhat.com> <1272303988-21929-7-git-send-email-glommer@redhat.com> <20100427134013.GE18410@amt.cnet> <4BD7270B.3030201@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <4BD7270B.3030201@redhat.com> X-ChuckNorris: True User-Agent: Jack Bauer Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 839 Lines: 19 On Tue, Apr 27, 2010 at 09:03:55PM +0300, Avi Kivity wrote: > On 04/27/2010 04:40 PM, Marcelo Tosatti wrote: > >On Mon, Apr 26, 2010 at 01:46:28PM -0400, Glauber Costa wrote: > >>If the HV told us we can fully trust the TSC, skip any > >>correction > >> > >Please drop this. Its not certain what is the best method to reduce > >contention on the global variable. Whatever it is, can be done later. > > > > The problem is lead time. If we (or the cpu vendors) fix this in > the hypervisor/processors in a year, then we want existing guests to > take advantage of it immediately. 100 % Agreed. -- 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/