Re: hackbench vs select_idle_sibling; was: [tip:sched/core] sched/fair, cpumask: Export for_each_cpu_wrap()

From: Matt Fleming
Date: Mon Jun 05 2017 - 09:02:21 EST


On Fri, 19 May, at 04:00:35PM, Matt Fleming wrote:
> On Wed, 17 May, at 12:53:50PM, Peter Zijlstra wrote:
> >
> > Please test..
>
> Results are still coming in but things do look better with your patch
> applied.
>
> It does look like there's a regression when running hackbench in
> process mode and when the CPUs are not fully utilised, e.g. check this
> out:

This turned out to be a false positive; your patch improves things as
far as I can see.