On 30/05/22 15:16, Peter Zijlstra wrote: > 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. All features on/off knob + house-keeping sub-partition/mask seem to be what isolation users I could reach so far (OCP mostly) would indeed like to have in the future.