From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932735AbcCHP7Y (ORCPT ); Tue, 8 Mar 2016 10:59:24 -0500 Received: from mail-yw0-f174.google.com ([209.85.161.174]:34127 "EHLO mail-yw0-f174.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754147AbcCHP7Q (ORCPT ); Tue, 8 Mar 2016 10:59:16 -0500 Date: Tue, 8 Mar 2016 10:59:13 -0500 From: Tejun Heo To: lizefan@huawei.com, hannes@cmpxchg.org, a.p.zijlstra@chello.nl, mingo@redhat.com, acme@kernel.org Cc: linux-kernel@vger.kernel.org, cgroups@vger.kernel.org, kernel-team@fb.com Subject: Re: [PATCH 1/2] cgroup: implement cgroup_subsys->implicit_on_dfl Message-ID: <20160308155913.GA3447@mtj.duckdns.org> References: <1456351975-1899-1-git-send-email-tj@kernel.org> <1456351975-1899-2-git-send-email-tj@kernel.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1456351975-1899-2-git-send-email-tj@kernel.org> User-Agent: Mutt/1.5.24 (2015-08-30) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Feb 24, 2016 at 05:12:54PM -0500, Tejun Heo wrote: > Some controllers, perf_event for now and possibly freezer in the > future, don't really make sense to control explicitly through > "cgroup.subtree_control". For example, the primary role of perf_event > is identifying the cgroups of tasks; however, because the controller > also keeps a small amount of state per cgroup, it can't be replaced > with simple cgroup membership tests. > > This patch implements cgroup_subsys->implicit_on_dfl flag. When set, > the controller is implicitly enabled on all cgroups on the v2 > hierarchy so that utility type controllers such as perf_event can be > enabled and function transparently. > > An implicit controller doesn't show up in "cgroup.controllers" or > "cgroup.subtree_control", is exempt from no internal process rule and > can be stolen from the default hierarchy even if there are non-root > csses. > > v2: Reimplemented on top of the recent updates to css handling and > subsystem rebinding. Rebinding implicit subsystems is now a > simple matter of exempting it from the busy subsystem check. > > Signed-off-by: Tejun Heo Applying this one to cgroup/for-4.6. Waiting for the review of userland part on the second patch. Thanks. -- tejun