From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756035Ab1LBMlS (ORCPT ); Fri, 2 Dec 2011 07:41:18 -0500 Received: from relay1.mentorg.com ([192.94.38.131]:58955 "EHLO relay1.mentorg.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755590Ab1LBMlQ (ORCPT ); Fri, 2 Dec 2011 07:41:16 -0500 From: Pedro Alves Organization: CodeSourcery To: KAMEZAWA Hiroyuki Subject: Re: [rfc 2/3] fs, proc: Introduce the Children: line in /proc//status Date: Fri, 2 Dec 2011 12:41:04 +0000 User-Agent: KMail/1.13.6 (Linux/2.6.38-13-generic; KDE/4.7.2; x86_64; ; ) Cc: Cyrill Gorcunov , linux-kernel@vger.kernel.org, Andrew Morton , Tejun Heo , Andrew Vagin , Serge Hallyn , Pavel Emelyanov , Vasiliy Kulikov References: <20111129191252.769160532@openvz.org> <20111201095434.GR14515@moon> <20111202094010.ca2dee4c.kamezawa.hiroyu@jp.fujitsu.com> In-Reply-To: <20111202094010.ca2dee4c.kamezawa.hiroyu@jp.fujitsu.com> MIME-Version: 1.0 Content-Type: Text/Plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit Message-Id: <201112021241.04471.pedro@codesourcery.com> X-OriginalArrivalTime: 02 Dec 2011 12:41:06.0646 (UTC) FILETIME=[A9082F60:01CCB0EF] Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Friday 02 December 2011 00:40:10, KAMEZAWA Hiroyuki wrote: > > What about this one? > > --- > > fs, proc: Introduce the /proc//children entry > > > > There is no easy way to make a reverse parent->children chain > > from the task status, in turn children->parent provided with "PPid" > > field. > > > > So instead of walking over all pids in system to figure out what > > children the task have -- we add explicit /proc//children entry, > > since kernel already knows this kind of information but it was not > > yet exported. > > > > Signed-off-by: Cyrill Gorcunov > > Cc: Pavel Emelyanov > > Cc: Serge Hallyn > > Cc: KAMEZAWA Hiroyuki > > Yes, I like /children file. other points seems to be pointed out by other > reviewers. Any reason this is a file instead of a directory like /proc/PID/task/ ? $ sudo ls /proc/8167/task/ 8167 854 855 856 857 858 859 $ sudo ls /proc/8167/task/855/ attr clear_refs cpuset exe io loginuid mountinfo oom_adj pagemap sched smaps statm wchan auxv cmdline cwd fd latency maps mounts oom_score personality schedstat stack status cgroup comm environ fdinfo limits mem numa_maps oom_score_adj root sessionid stat syscall Much easier to follow the chain from the command line this way. -- Pedro Alves