From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757003AbYDJNk6 (ORCPT ); Thu, 10 Apr 2008 09:40:58 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1753723AbYDJNkv (ORCPT ); Thu, 10 Apr 2008 09:40:51 -0400 Received: from mailhub.sw.ru ([195.214.232.25]:5306 "EHLO relay.sw.ru" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752198AbYDJNku (ORCPT ); Thu, 10 Apr 2008 09:40:50 -0400 Message-ID: <47FE1219.5010405@parallels.com> Date: Thu, 10 Apr 2008 17:11:53 +0400 From: Kirill Korotaev Organization: Parallels User-Agent: Thunderbird 2.0.0.6 (X11/20071022) MIME-Version: 1.0 To: Andi Kleen CC: Cedric Le Goater , "David C. Hansen" , linux-kernel@vger.kernel.org, Containers , Pavel Emelyanov Subject: Re: [PATCH 1/3] change clone_flags type to u64 References: <20080409222611.GA28087@us.ibm.com> <20080409223231.GA28267@us.ibm.com> <871w5enmk7.fsf@basil.nowhere.org> <47FE073B.3060007@fr.ibm.com> <20080410125205.GG10019@one.firstfloor.org> In-Reply-To: <20080410125205.GG10019@one.firstfloor.org> Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org The was no real rationale except for some people seeing "clone" functionality as the match and the fact that FS_NAMESCAPE was done so made them believe it is a good way to go. And I warned about flags limitation at the beginning. Both OpenVZ/vserver suggested to use a special syscall for handling this. Maybe it is a good point to switch to it now finally and stop worring about all this? Andi Kleen wrote: >> I guess that was a development rationale. > > But what rationale? It just doesn't make much sense to me. > >> Most of the namespaces are in >> use in the container projects like openvz, vserver and probably others >> and we needed a way to activate the code. > > You could just have added it to feature groups over time. > >> Not perfect I agree. >> >>> With your current strategy are you sure that even 64bit will >>> be enough in the end? For me it rather looks like you'll >>> go through those quickly too as more and more of the kernel >>> is namespaced. >> well, we're reaching the end. I hope ! devpts is in progress and >> mq is just waiting for a clone flag. > > Are you sure? > >> >>> Also I think the user interface is very unfriendly. How >>> is a non kernel hacker supposed to make sense of these >>> myriads of flags? You'll be creating another >>> CreateProcess123_extra_args_extended() >>> in the end I fear. >> well, the clone interface is a not friendly interface anyway. glibc wraps >> it > > But only for the stack setup which is just a minor detail. > > The basic clone() flags interface used to be pretty sane and usable > before it could overloaded with so many tiny features. > > I especially worry on how user land should keep track of changing kernel > here. If you add new feature flag for lots of kernel features it is > reasonable to expect that in the future there will be often new features. > > Does this mean user land needs to be updated all the time? Will this > end up like another udev? > >> We will need a user library, like we have a libphtread or a libaio, to > > That doesn't make sense. The basic kernel syscalls should be usable, > not require some magic library that would likely need intimate > knowledge of specific kernel versions to do any good. > >> but we still need a way to extend the clone flags because none are left. > > Can we just take out some again that were added in the .25 cycle and > readd them once there is a properly thought out interface? That would > leave at least one. > > -Andi > _______________________________________________ > Containers mailing list > Containers@lists.linux-foundation.org > https://lists.linux-foundation.org/mailman/listinfo/containers >