From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757207AbaE2KUq (ORCPT ); Thu, 29 May 2014 06:20:46 -0400 Received: from a.ns.miles-group.at ([95.130.255.143]:47834 "EHLO radon.swed.at" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756095AbaE2KUo (ORCPT ); Thu, 29 May 2014 06:20:44 -0400 Message-ID: <538709A5.60000@nod.at> Date: Thu, 29 May 2014 12:19:17 +0200 From: Richard Weinberger User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:24.0) Gecko/20100101 Thunderbird/24.1.0 MIME-Version: 1.0 To: Pavel Emelyanov CC: Vasily Kulikov , containers@lists.linux-foundation.org, Serge Hallyn , linux-kernel@vger.kernel.org, Oleg Nesterov , David Howells , "Eric W. Biederman" , Andrew Morton , Al Viro Subject: Re: [PATCH v2] /proc/pid/status: show all sets of pid according to ns References: <1401272683-1659-1-git-send-email-chenhanxiao@cn.fujitsu.com> <5385DA19.2060008@parallels.com> <20140528182824.GA5057@cachalot> <53863889.9080509@parallels.com> <20140529055954.GA10354@cachalot> <5386F8EA.8050501@parallels.com> <5386FC0C.9000307@nod.at> <538700B5.5070601@parallels.com> <538703D0.7030308@nod.at> <5387059E.9010105@parallels.com> In-Reply-To: <5387059E.9010105@parallels.com> X-Enigmail-Version: 1.6 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 Am 29.05.2014 12:02, schrieb Pavel Emelyanov: >>> We need to know what pid namespaces a task lives in and how pid, sid and >>> pgid look in all of them. A short example with pids only >> >> So use case is to checkpoint/restore nested containers? :) > > Yes, but there's one more scenario. AFAIK some applications create pid namespaces > themselves, without starting what is typically called "a container" :) And when > such an applications are run inside, well ... "more real" container (e.g. using > openvz, lxc or docker tools) we face this issue. Do you know such an application? I'm a aware of systemd which uses CLONE_NEWNET/NS to implement security features. We could add a directory like /proc//ns/proc/ which would contain everything from /proc//. This needs definitely more discussion and must not solved by ad-hoc solutions. Thanks, //richard