Re: [RFC PATCH 12/12] housekeeping: Reimplement isolcpus on housekeeping

[Peter Zijlstra]

On Wed, Aug 23, 2017 at 03:51:11AM +0200, Frederic Weisbecker wrote:
> We want to centralize the isolation features on the housekeeping
> subsystem and scheduler isolation is a significant part of it.
> 
> While at it, this is a proposition for a reimplementation of isolcpus=
> that doesn't involve  scheduler domain isolation. Therefore this
> brings a behaviour change: all user tasks inherit init/1 affinity which
> avoid the isolcpus= range. But if a task later overrides its affinity
> which turns out to intersect an isolated CPU, load balancing may occur
> on it.
> 
> OTOH such a reimplementation that doesn't shortcut scheduler internals
> makes a better candidate for an interface extension to cpuset.

Not sure we can do this. It'll break users that rely on the no
scheduling thing, that's a well documented part of isolcpus.