Re: [PATCH cgroup/for-4.15] cgroup, sched: Move basic cpu stats from cgroup.stat to cpu.stat

From: Peter Zijlstra
Date: Tue Oct 24 2017 - 04:35:25 EST


On Mon, Oct 23, 2017 at 04:18:27PM -0700, Tejun Heo wrote:
> The basic cpu stat is currently shown with "cpu." prefix in
> cgroup.stat, and the same information is duplicated in cpu.stat when
> cpu controller is enabled. This is ugly and not very scalable as we
> want to expand the coverage of stat information which is always
> available.
>
> This patch makes cgroup core always create "cpu.stat" file and show
> the basic cpu stat there and calls the cpu controller to show the
> extra stats when enabled. This ensures that the same information
> isn't presented in multiple places and makes future expansion of basic
> stats easier.
>
> Signed-off-by: Tejun Heo <tj@xxxxxxxxxx>
> ---
> Hello,
>
> The more I think about showing cpu stat in cgroup.stat, the uglier it
> seems.

I've not been paying much attention to this, could you elaborate on the
problems there?

> This patch flips it so that "cpu.stat" is always available
> with basic cpu stat instead. It only changes the presentation and
> changes to the scheduler code is minimal. Will route with the other
> cpu controller changes through cgroup/for-4.15 unless there are
> objections.

And this is -v2 only? I'm a little lost on how all that connects.