From mboxrd@z Thu Jan 1 00:00:00 1970 From: Nicolas Dichtel Subject: Re: [RFC PATCH net-next 0/5] Ease netns management for userland Date: Wed, 19 Dec 2012 10:47:03 +0100 Message-ID: <50D18D17.4060502@6wind.com> References: <1355332630-4256-1-git-send-email-nicolas.dichtel@6wind.com> <87fw3boyxn.fsf@xmission.com> <50C8EEF0.2010201@6wind.com> <87zk1jht7d.fsf@xmission.com> <87sj7beyc1.fsf@xmission.com> <50CA135A.7060802@6wind.com> <87mwxh6a8y.fsf@xmission.com> <50CB5047.8060804@6wind.com> <87zk1g8tnq.fsf@xmission.com> Reply-To: nicolas.dichtel@6wind.com Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: QUOTED-PRINTABLE Cc: netdev@vger.kernel.org, davem@davemloft.net, aatteka@nicira.com To: "Eric W. Biederman" Return-path: Received: from mail-ee0-f46.google.com ([74.125.83.46]:59413 "EHLO mail-ee0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753702Ab2LSJxK (ORCPT ); Wed, 19 Dec 2012 04:53:10 -0500 Received: by mail-ee0-f46.google.com with SMTP id e53so870335eek.5 for ; Wed, 19 Dec 2012 01:53:09 -0800 (PST) In-Reply-To: <87zk1g8tnq.fsf@xmission.com> Sender: netdev-owner@vger.kernel.org List-ID: Le 14/12/2012 17:50, Eric W. Biederman a =C3=A9crit : > Nicolas Dichtel writes: > >> Le 13/12/2012 20:08, Eric W. Biederman a =C3=A9crit : > >>> No. The difficulty monitoring which network namespaces are being u= sed >>> is an unintended side effect. >> Why is netlink a bad idea? Having a way to know all existing netns i= s a start >> point to monitor netns, isn't it? > > In the same way that having a neighbour table that contains all exist= ing > ip address to mac addresses mappings is a starting point to monitor a= ll > existing hosts. > > All does not scale. > > All removes a lot of perfectly valid use cases like checkpoint-restar= t, > and nesting containers. > > All as different from what is already implemented requires implementi= ng > yet another namespace to put the names of all into it. We have enoug= h > namespaces now thank you very much. > > An unfiltered global list is about as interesting to use as putting > all files in /. Sure you know which directory you put your file in b= ut > which file is it? > > What has already been implemented should be roughly as good for > monitoring as what is available with lsof. > > And of course there is the fact that a global list of anything that i= s > the same from every perspective violates the principle of relativity, > and is in contradiction with the phsical reality in which we exist. > > So there is no way that having a global all inclusive list of network > namespaces makes the least lick of sense and I really don't want to > think about it. Thank you for your explanations and your patience, this is very useful. Nicolas