Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756575Ab0D0SEF (ORCPT ); Tue, 27 Apr 2010 14:04:05 -0400 Received: from mx1.redhat.com ([209.132.183.28]:46204 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756509Ab0D0SEA (ORCPT ); Tue, 27 Apr 2010 14:04:00 -0400 Message-ID: <4BD7270B.3030201@redhat.com> Date: Tue, 27 Apr 2010 21:03:55 +0300 From: Avi Kivity User-Agent: Mozilla/5.0 (X11; U; Linux x86_64; en-US; rv:1.9.1.9) Gecko/20100330 Fedora/3.0.4-1.fc12 Thunderbird/3.0.4 MIME-Version: 1.0 To: Marcelo Tosatti CC: Glauber Costa , kvm@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH 6/6] don't compute pvclock adjustments if we trust the tsc 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> In-Reply-To: <20100427134013.GE18410@amt.cnet> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 858 Lines: 24 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. -- Do not meddle in the internals of kernels, for they are subtle and quick to panic. -- 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/