Re: [RFC PATCH 4/4] cpuset: Support RCU-NOCB toggle on v2 root partitions

[Peter Zijlstra]

On Mon, May 30, 2022 at 12:56:50PM +0200, Frederic Weisbecker wrote:

> > This is ABI, you can't walk back on it. I would suggest starting with an
> > 'all feature' isolation. Only if there's real demand for something more
> > fine-grained add that on top. Simple first etc.
> 
> That's actually my worry. If we start with an all in one ABI, how do we later
> mix that up with more finegrained features? Like what will be the behaviour of:
> 
> cpuset.isolation.rcu_nocb = 0
> cpuset.isolation.all = 1

Well clearly that doesn't make sense. I was more thinking along the
lines of cgroup.subtree_control, where instead all features are enabled
by default.

But only if there's a real usecase, otherwise there's no point in
providing such knobs.