Re: [PATCH] cpuset: Enforce that a child's cpus must be a subset of the parent

Tejun Heo
2018-06-06T20:56:35Z

Hello, Peter.

Sorry about late reply.

On Thu, May 31, 2018 at 06:38:26PM +0200, Peter Zijlstra wrote:
> > Yeah, for cpuset, it's messier, but it isn't different from hotunplug
> > scenario, right? I think the best we can do there is putting ancestor
> > operation on an equal footing as hotplug ops.
>
> Right, but hotplug is exceedingly rare, while I get the impression you
> think it is perfectly fine to recind on your resource grants.

Well, yeah, for a trivial example, imagine dynamic workload management
where you wanna restrict what a side-loaded batch workload can do on
and off peak hours. All other controllers can do that. It'd be a
really odd design trade-off if we make that really clumsy for cpuset
especially given that we wouldn't be gaining any actual
functionalities.

Thanks.

--
tejun