Re: [RFC] sched: unused cpu in affine workload

From: Peter Zijlstra
Date: Mon Apr 04 2016 - 09:23:30 EST


On Mon, Apr 04, 2016 at 11:38:44AM +0200, Ingo Molnar wrote:
> We'd upgrade that to O(nr_cpus^2), which is totally unrealistic with 16,000 CPUs
> even in a slowpath - but it would probably cause problems even with 120 CPUs. It
> will get quadratically worse as the number of CPUs in a system increases on its
> current exponential trajectory ...

The arbitrary affinity thing is I think a packing problem, which is NP
hard IIRC.