Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1030260AbWBTOoF (ORCPT ); Mon, 20 Feb 2006 09:44:05 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1030259AbWBTOoF (ORCPT ); Mon, 20 Feb 2006 09:44:05 -0500 Received: from mailhub.sw.ru ([195.214.233.200]:42393 "EHLO relay.sw.ru") by vger.kernel.org with ESMTP id S1030260AbWBTOoC (ORCPT ); Mon, 20 Feb 2006 09:44:02 -0500 Message-ID: <43F9D5DF.6030009@sw.ru> Date: Mon, 20 Feb 2006 17:44:47 +0300 From: Kirill Korotaev User-Agent: Mozilla/5.0 (X11; U; Linux i686; ru-RU; rv:1.2.1) Gecko/20030426 X-Accept-Language: ru-ru, en MIME-Version: 1.0 To: Herbert Poetzl CC: "Eric W. Biederman" , "Serge E. Hallyn" , linux-kernel@vger.kernel.org, vserver@list.linux-vserver.org, Alan Cox , Dave Hansen , Arjan van de Ven , Suleiman Souhlal , Hubertus Franke , Cedric Le Goater , Kyle Moffett , Greg , Linus Torvalds , Andrew Morton , Greg KH , Rik van Riel , Alexey Kuznetsov , Andrey Savochkin , Kirill Korotaev , Andi Kleen , Benjamin Herrenschmidt , Jeff Garzik , Trond Myklebust , Jes Sorensen Subject: Re: (pspace,pid) vs true pid virtualization References: <20060215145942.GA9274@sergelap.austin.ibm.com> <20060216143030.GA27585@MAIL.13thfloor.at> <43F990CA.5080102@sw.ru> <20060220130020.GD17478@MAIL.13thfloor.at> In-Reply-To: <20060220130020.GD17478@MAIL.13thfloor.at> Content-Type: text/plain; charset=us-ascii; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2050 Lines: 52 >>fine, agreed on this finally, same for OpenVZ. > hey we have soemthing :) :) >>>definitely, we (Linux-VServer) added this some time ago >>>and it helps to maintain/restart a guest. >>but why sys_waitpid? we can make it in many other ways, > > yes, we currently have a syscall switch command > to wait for the guest, but, of course, it is > very similar to the 'normal' unix waitpid() this is more logically clean to me, since containers/namespaces are not tasks. If someone wants to use more unix-like semantics, he can obtain fd for namespace and call select/poll on it :)))) >>And we had issues in OpenVZ, that very fast VPS stop/start can fail due >>to not freed resources yet. > this is a design problem, if your design allows > to have _more_ than one pid space with the same > identifier/properties, but with only one active > and thus reachable space, it is no problem to > create a new one right after the old one did send > the event (which doesn't mean that it was destroyed > just that the last process left the space) see my another email about sockets. >>How about third party apps? > I don't think we care about third party apps when > adding new kernel functionality, especially not > proprietary ones which cannot be modified easily Even if we don't take into account proprietary apps, there too many opensource control panels, management tools etc. So this doesn't look good to me anyhow. >>agreed. Though I don't like a backdoor name :) >>It is just a way to get access to VPS. > well, it is often a way to get access to the VPS > without the 'owner' of that VPS even knowing, so > IMHO it's a backdoor, access would be via sshd or > console :) When you have a physical box there are many ways to get access to it without knowing passwords etc. This is the same. 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/