Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755712AbZJGWkM (ORCPT ); Wed, 7 Oct 2009 18:40:12 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1755621AbZJGWkL (ORCPT ); Wed, 7 Oct 2009 18:40:11 -0400 Received: from rcsinet12.oracle.com ([148.87.113.124]:36428 "EHLO rgminet12.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755604AbZJGWkJ convert rfc822-to-8bit (ORCPT ); Wed, 7 Oct 2009 18:40:09 -0400 MIME-Version: 1.0 Message-ID: Date: Wed, 7 Oct 2009 15:36:58 -0700 (PDT) From: Dan Magenheimer To: Avi Kivity Cc: Jeremy Fitzhardinge , Jeremy Fitzhardinge , Xen-devel , kurt.hackel@oracle.com, the arch/x86 maintainers , Linux Kernel Mailing List , Glauber de Oliveira Costa , Keir Fraser , zach.brown@oracle.com, chris.mason@oracle.com Subject: RE: [Xen-devel] Re: [PATCH 3/5] x86/pvclock: add vsyscall implementation In-Reply-To: <4ACD0333.9060603@redhat.com> X-Priority: 3 X-Mailer: Oracle Beehive Extensions for Outlook 1.5.1.4 (308245) [OL 9.0.0.6627] Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 8BIT X-Source-IP: acsmt357.oracle.com [141.146.40.157] X-Auth-Type: Internal IP X-CT-RefId: str=0001.0A090206.4ACD1851.00D0:SCFMA4539814,ss=1,fgs=0 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1455 Lines: 42 > Then they will get incorrect timing once they are live migrated. I've posted a proposed (OS-independent) solution for that and am (slowly) in the process of implementing it. > -----Original Message----- > From: Avi Kivity [mailto:avi@redhat.com] > Sent: Wednesday, October 07, 2009 3:08 PM > To: Dan Magenheimer > Cc: Jeremy Fitzhardinge; Jeremy Fitzhardinge; Xen-devel; Kurt Hackel; > the arch/x86 maintainers; Linux Kernel Mailing List; Glauber > de Oliveira > Costa; Keir Fraser; Zach Brown; Chris Mason > Subject: Re: [Xen-devel] Re: [PATCH 3/5] x86/pvclock: add vsyscall > implementation > > > On 10/07/2009 10:48 PM, Dan Magenheimer wrote: > >> We can support them by falling back to the kernel. I'm a > bit worried > >> about the kernel playing with the hypervisor's version field. It's > >> better to introduce yet a new version for the kernel, and > check both. > >> > > On Nehalem, apps that need timestamp information at a high > > frequency will likely use rdtsc/rdtscp directly. > > > > > > Then they will get incorrect timing once they are live migrated. > > -- > I have a truly marvellous patch that fixes the bug which this > signature is too narrow to contain. > > > -- 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/