Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752780AbdLDVfT (ORCPT ); Mon, 4 Dec 2017 16:35:19 -0500 Received: from mail-wm0-f53.google.com ([74.125.82.53]:35293 "EHLO mail-wm0-f53.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752326AbdLDVfS (ORCPT ); Mon, 4 Dec 2017 16:35:18 -0500 X-Google-Smtp-Source: AGs4zMZe0wJ5mVA1TktNe7E/gq8fDU9C9nS4ff8U2Hg385aZ1++Q7Fev29gGC69gOqXQjTkUNixssQ== From: "Michael Kerrisk (man-pages)" Subject: Writing "+pids" to cgroup.subtree_control flie yields EINVAL To: Tejun Heo Cc: mtk.manpages@gmail.com, lkml Message-ID: Date: Mon, 4 Dec 2017 22:35:13 +0100 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:52.0) Gecko/20100101 Thunderbird/52.3.0 MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 623 Lines: 22 Hello Tejun, I was trying to do some simple testing ot the CPU controller that is merged into 4.15, and ran immediately into some confusion. In the root cgroup on a freshly booted 4.150-rc1, I try the following: # pwd /sys/fs/cgroup/unified # echo '+cpu' > cgroup.subtree_control sh: echo: write error: Invalid argument What am I missing> I presume I'm missing something obvious, although nothing jumped out at me as I read the cgroups-v2.txt file. Cheers, Michael -- Michael Kerrisk Linux man-pages maintainer; http://www.kernel.org/doc/man-pages/ Linux/UNIX System Programming Training: http://man7.org/training/