Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1030271AbWBTPQX (ORCPT ); Mon, 20 Feb 2006 10:16:23 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1030282AbWBTPQX (ORCPT ); Mon, 20 Feb 2006 10:16:23 -0500 Received: from MAIL.13thfloor.at ([212.16.62.50]:62947 "EHLO mail.13thfloor.at") by vger.kernel.org with ESMTP id S1030271AbWBTPQW (ORCPT ); Mon, 20 Feb 2006 10:16:22 -0500 Date: Mon, 20 Feb 2006 16:16:20 +0100 From: Herbert Poetzl To: Kirill Korotaev Cc: Hubertus Franke , "Eric W. Biederman" , "Serge E. Hallyn" , Sam Vilain , Rik van Riel , Kirill Korotaev , Linus Torvalds , Andrew Morton , linux-kernel@vger.kernel.org, clg@fr.ibm.com, haveblue@us.ibm.com, greg@kroah.com, alan@lxorguk.ukuu.org.uk, arjan@infradead.org, kuznet@ms2.inr.ac.ru, saw@sawoct.com, devel@openvz.org, Dmitry Mishin , Andi Kleen Subject: Re: The issues for agreeing on a virtualization/namespaces implementation. Message-ID: <20060220151620.GB18841@MAIL.13thfloor.at> Mail-Followup-To: Kirill Korotaev , Hubertus Franke , "Eric W. Biederman" , "Serge E. Hallyn" , Sam Vilain , Rik van Riel , Kirill Korotaev , Linus Torvalds , Andrew Morton , linux-kernel@vger.kernel.org, clg@fr.ibm.com, haveblue@us.ibm.com, greg@kroah.com, alan@lxorguk.ukuu.org.uk, arjan@infradead.org, kuznet@ms2.inr.ac.ru, saw@sawoct.com, devel@openvz.org, Dmitry Mishin , Andi Kleen References: <43E83E8A.1040704@vilain.net> <43E8D160.4040803@watson.ibm.com> <20060207201908.GJ6931@sergelap.austin.ibm.com> <43E90716.4020208@watson.ibm.com> <43E92EDC.8040603@watson.ibm.com> <43F9B1F4.4040907@sw.ru> <20060220124103.GB17478@MAIL.13thfloor.at> <43F9D185.8020906@sw.ru> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <43F9D185.8020906@sw.ru> User-Agent: Mutt/1.5.6i Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1995 Lines: 60 On Mon, Feb 20, 2006 at 05:26:13PM +0300, Kirill Korotaev wrote: >> as does Linux-VServer currently, but do you have >> any proof that putting all the fields together in >> one big structure actually has any (dis)advantage >> over separate structures? > have no proof and don't mind if there are many pointers. > Though this doesn't look helpful to me as well. well, my point is just that we don't know yet so we should not favor one over the other, just because somebody did it like that and it didn't hurt :) >>> mmm, how do you plan to pass additional flags to clone()? >>> e.g. strong or weak isolation of pids? >> do you really have to pass them at clone() time? >> would shortly after be more than enough? >> what if you want to change those properties later? > I don't think it is always suiatable to do configuration later. > We had races in OpenVZ on VPS create/stop against exec/enter etc. > (even introduced flag is_running). > So I have some experience to believe it will be painfull place. well, Linux-VServer uses a state called 'setup' which allows to change all kinds of things before the guest can be entered, this state is changed as the last operation of the setup, which in turn drops all the capabilities and makes the guest visible to the outside ... works quite well and seems to be free of those races you mentioned ... >>> this syscalls will start handling this new namespace and that's all. >>> this is not different from many syscalls approach. >> well, let's defer the 'how amny syscalls' issue to >> a later time, when we know what we want to implement :) > agreed. btw, maybe it's just me, but would it be possible to do the email quoting like this: >>> Text instead of > >>Text TIA, Herbert > Kirill - 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/