Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756670AbZJVQXf (ORCPT ); Thu, 22 Oct 2009 12:23:35 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1756567AbZJVQXe (ORCPT ); Thu, 22 Oct 2009 12:23:34 -0400 Received: from mx1.redhat.com ([209.132.183.28]:1025 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755595AbZJVQXe (ORCPT ); Thu, 22 Oct 2009 12:23:34 -0400 Message-ID: <4AE08708.6070302@redhat.com> Date: Thu, 22 Oct 2009 18:23:36 +0200 From: Avi Kivity User-Agent: Mozilla/5.0 (X11; U; Linux x86_64; en-US; rv:1.9.1.1) Gecko/20090814 Fedora/3.0-2.6.b3.fc11 Thunderbird/3.0b3 MIME-Version: 1.0 To: Glauber Costa CC: kvm@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH] allow userspace to adjust kvmclock offset References: <1254849896-3947-1-git-send-email-glommer@redhat.com> <4AD2EE86.50807@redhat.com> <20091013122828.GZ8092@mothafucka.localdomain> <4AD4730C.9010305@redhat.com> <20091013124638.GC8092@mothafucka.localdomain> <4AD670FC.7010004@redhat.com> <20091015145855.GI8092@mothafucka.localdomain> In-Reply-To: <20091015145855.GI8092@mothafucka.localdomain> Content-Type: text/plain; charset=ISO-8859-1; 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: 1155 Lines: 27 On 10/15/2009 04:58 PM, Glauber Costa wrote: > >> The motivation for relative adjustment is when you have a jitter >> resistant place to gather timing information (like the kernel, which can >> disable interrupts and preemption), then pass it on to kvm without >> losing information due to scheduling. For migration there is no such >> place since it involves two hosts, but it makes sense to support >> relative adjustments. >> > Since we added the padding you asked for, we could use that bit of information > to define whether it will be a relative or absolute adjustment, then. Right now, > I don't see the point of implementing a code path that will be completely untested. > > I'd leave it this way until someone comes up with a need. > I agree with that, but padding by itself is insufficient. You also need a flags field. -- error compiling committee.c: too many arguments to function -- 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/