Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755964AbXHUIHI (ORCPT ); Tue, 21 Aug 2007 04:07:08 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751194AbXHUIGw (ORCPT ); Tue, 21 Aug 2007 04:06:52 -0400 Received: from mtagate6.de.ibm.com ([195.212.29.155]:5879 "EHLO mtagate6.de.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751280AbXHUIGu (ORCPT ); Tue, 21 Aug 2007 04:06:50 -0400 From: Christian Borntraeger To: kvm-devel@lists.sourceforge.net Subject: Re: [kvm-devel] =?iso-8859-1?q?R=E9f=2E_=3A_Re=3A_=5BPATCH_0/4=5D_Virtual_Machine_Time?= =?iso-8859-1?q?_Accounting?= Date: Tue, 21 Aug 2007 10:06:42 +0200 User-Agent: KMail/1.9.7 Cc: "Glauber de Oliveira Costa" , "laurent.vivier@bull.net" , Jeremy Fitzhardinge , John Stoffel , linux-kernel , virtualization References: <5d6222a80708201334q27fc6cbcr7ce6a9d7147437a2@mail.gmail.com> In-Reply-To: <5d6222a80708201334q27fc6cbcr7ce6a9d7147437a2@mail.gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit Content-Disposition: inline Message-Id: <200708211006.42938.borntraeger@de.ibm.com> Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1211 Lines: 24 Am Montag, 20. August 2007 schrieb Glauber de Oliveira Costa: > Although I don't know KVM to a that deep level, I think it should be > possible to keep the virtual cpus in different process (or threads), > and take the accounting time from there. Perfectly possible to know > the time we spent running (user time), and the time the hypervisor > spent doing things on our behalf (system time). I disagree here. First thing, you dont want to have the virtual cpu in a different process than the hypervisor control code for that cpu. Otherwise communication has to be made via IPC. Secondly, Its not qemu/kvm that does the accouting. Its existing userspace code like top/snmp agents and clients! etc. that would require additional knowledge which thread is guest code. I personally like the approach Laurent has taken. Maybe it needs some polish and maybe we want an account_guest_time function, but in general I think he is doing the right thing. Christian - 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/