Re: [PATCH for-4.4-fixes] cgroup_pids: don't account for the root cgroup

[Tejun Heo <tj@kernel.org>]

On Mon, Nov 30, 2015 at 05:45:43PM -0500, Tejun Heo wrote:
> From 7bbb8d4e913853a1346d95745ca8092f0cc8ce00 Mon Sep 17 00:00:00 2001
> From: Tejun Heo <tj@kernel.org>
> Date: Mon, 30 Nov 2015 17:24:34 -0500
> 
> Because accounting resources for the root cgroup sometimes incurs
> measureable overhead for workloads which don't care about cgroup and
> often ends up calculating a number which is available elsewhere in a
> slightly different form, cgroup is not in the business of providing
> system-wide statistics.  The pids controller which was introduced
> recently was exposing "pids.current" at the root.  This patch disable
> accounting for root cgroup and removes the file from the root
> directory.
> 
> While this is a userland visible behavior change, pids has been
> available only in one version and was badly broken there, so I don't
> think this will be noticeable.  If it turns out to be a problem, we
> can reinstate it for v1 hierarchies.
> 
> Signed-off-by: Tejun Heo <tj@kernel.org>
> Cc: Aleksa Sarai <cyphar@cyphar.com>

Applying to cgroup/for-4.4-fixes.

Thanks.

-- 
tejun