Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751561AbeAJW3S (ORCPT + 1 other); Wed, 10 Jan 2018 17:29:18 -0500 Received: from mail-qk0-f176.google.com ([209.85.220.176]:39006 "EHLO mail-qk0-f176.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751834AbeAJW3Q (ORCPT ); Wed, 10 Jan 2018 17:29:16 -0500 X-Google-Smtp-Source: ACJfBothuFr7NdKqbsB1i28DKjpuWguVyg0BQZ0yCXHaiBGv1a3SRU6PxgvSIIrD/xXy9tzTqEegQA== Date: Wed, 10 Jan 2018 14:29:13 -0800 From: Tejun Heo To: "Michael Kerrisk (man-pages)" Cc: Peter Zijlstra , cgroups@vger.kernel.org, lkml , linux-man , "Serge E. Hallyn" , Mike Galbraith , Li Zefan , Ingo Molnar , Paul Turner , kernel-team@fb.com, Andy Lutomirski , Johannes Weiner , Lauro Venancio , Waiman Long Subject: Re: cgroups(7): documenting cgroups v2 thread mode Message-ID: <20180110222913.GH3460072@devbig577.frc2.facebook.com> References: <20180109211000.GT3668920@devbig577.frc2.facebook.com> <5c9ea5dd-12dc-99d6-7905-40fdbc34e6ae@gmail.com> <20180110144708.GC3668920@devbig577.frc2.facebook.com> <704d0cd5-0bab-f876-a09c-9d60e9d2ef93@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <704d0cd5-0bab-f876-a09c-9d60e9d2ef93@gmail.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 Return-Path: Hello, On Wed, Jan 10, 2018 at 11:18:48PM +0100, Michael Kerrisk (man-pages) wrote: > Ahh yes. Now I understand. I made the description of the containment > rules for cgroup.threads more explicit in the text: > > As with writing to cgroup.procs, some containment rules apply when > writing to the cgroup.threads file: > > * The writer must have write permission on the cgroup.threads > file in the destination cgroup. > > * The writer must have write permission on the cgroup.procs file > in the common ancestor of the source and destination cgroups. > (In some cases, the common ancestor may be the source or desti‐ > nation cgroup itself.) > > * The source and destination cgroups must be in the same threaded > subtree. (Outside a threaded subtree, an attempt to move a > thread by writing its thread ID to the cgroup.threads in a dif‐ > ferent domain cgroup fails with the error EOPNOTSUPP.) > > Okay? (I realize that the last bullet point is a rather different way of > formulating your idea that "the only extra restriction is that the domain > cgroup must be the same for the source and destination". But I think the > reformulation is easier to understand, no?) It looks great to me. Me explaining that way is mostly from internal / conceptual POV. Yours is definitely more approachable. Thanks. -- tejun