From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S964917AbWDGTlZ (ORCPT ); Fri, 7 Apr 2006 15:41:25 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S964916AbWDGTlZ (ORCPT ); Fri, 7 Apr 2006 15:41:25 -0400 Received: from ebiederm.dsl.xmission.com ([166.70.28.69]:42945 "EHLO ebiederm.dsl.xmission.com") by vger.kernel.org with ESMTP id S964915AbWDGTlY (ORCPT ); Fri, 7 Apr 2006 15:41:24 -0400 To: "Serge E. Hallyn" Cc: linux-kernel@vger.kernel.org, Kirill Korotaev , herbert@13thfloor.at, devel@openvz.org, sam@vilain.net, xemul@sw.ru, James Morris Subject: Re: [RFC][PATCH 0/5] uts namespaces: Introduction References: <20060407095132.455784000@sergelap> <20060407192800.GE28729@sergelap.austin.ibm.com> From: ebiederm@xmission.com (Eric W. Biederman) Date: Fri, 07 Apr 2006 13:39:20 -0600 In-Reply-To: <20060407192800.GE28729@sergelap.austin.ibm.com> (Serge E. Hallyn's message of "Fri, 7 Apr 2006 14:28:00 -0500") Message-ID: User-Agent: Gnus/5.1007 (Gnus v5.10.7) Emacs/21.4 (gnu/linux) MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org "Serge E. Hallyn" writes: > Quoting Eric W. Biederman (ebiederm@xmission.com): >> "Serge E. Hallyn" writes: >> >> > Introduce utsname namespaces. Instead of a single system_utsname >> > containing hostname domainname etc, a process can request it's >> > copy of the uts info to be cloned. The data will be copied from >> > it's original, but any further changes will not be seen by processes >> > which are not it's children, and vice versa. >> > >> > This is useful, for instance, for vserver/openvz, which can now clone >> > a new uts namespace for each new virtual server. >> > >> > This patchset is based on Kirill Korotaev's Mar 24 submission, taking >> > comments (in particular from James Morris and Eric Biederman) into >> > account. >> > >> > Some performance results are attached. I was mainly curious whether >> > it would be worth putting the task_struct->uts_ns pointer inside >> > a #ifdef CONFIG_UTS_NS. The result show that leaving it in when >> > CONFIG_UTS_NS=n has negligable performance impact, so that is the >> > approach this patch takes. >> >> Ok. This looks like the best version so far. >> >> I like the utsname() function thing to shorten the >> idiom of current->uts_ns->name. >> >> We probably want to introduce utsname() and an init_utsname() >> before any of the other changes, and then perform the substitutions, > > This is the same as what Sam is saying, right? Just making sure I > understand. Yes. >> before we actually change the code so the patchset can make it >> through a git-bisect. This will also allows for something > > Ok, I've finally got the rest of git doing my bidding, I'll go read > up on git-bisect. Basically git-bisect is an automated binary search through patches to help find bugs. If you ever can't compile at an intermediate patch git-bisect and other people walking through the patches looking for bugs won't like it. It's not mandatory that you never break anything in a patchset, but it is much friendlier when you can avoid breakage. Eric