From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932581AbaE2GAA (ORCPT ); Thu, 29 May 2014 02:00:00 -0400 Received: from mail-la0-f45.google.com ([209.85.215.45]:59032 "EHLO mail-la0-f45.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751834AbaE2F77 (ORCPT ); Thu, 29 May 2014 01:59:59 -0400 Date: Thu, 29 May 2014 09:59:54 +0400 From: Vasily Kulikov To: Pavel Emelyanov Cc: Richard Weinberger , 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 Message-ID: <20140529055954.GA10354@cachalot> References: <1401272683-1659-1-git-send-email-chenhanxiao@cn.fujitsu.com> <5385DA19.2060008@parallels.com> <20140528182824.GA5057@cachalot> <53863889.9080509@parallels.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <53863889.9080509@parallels.com> User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, May 28, 2014 at 23:27 +0400, Pavel Emelyanov wrote: > On 05/28/2014 10:28 PM, Vasily Kulikov wrote: > > On Wed, May 28, 2014 at 16:44 +0400, Pavel Emelyanov wrote: > > It will be simplier > > to parse the file -- if 'ns_ids' file contains some ID then this ID for > > every ns can be obtained regardless of the specific ID name (SID, PID, > > PGID, etc.). > > True, but given a task PID how to determine which pid namespaces it lives in > to get the idea of how PIDs map to each other? Maybe we need some explicit > API for converting (ID, NS1, NS2) into (ID)? AFAIU the idea of the patch is to add a new debugging information which can be trivially obtained via 'cat /proc/...': ] We need a direct method of getting the pid inside containers. ] If some issues occurred inside container guest, host user ] could not know which process is in trouble just by guest pid: ] the users of container guest only knew the pid inside containers. ] This will bring obstacle for trouble shooting. A new syscall might complicate trouble shooting by admin. -- Vasily Kulikov http://www.openwall.com - bringing security into open computing environments