Re: sysbench throughput degradation in 4.13+

Peter Zijlstra
2017-10-03T08:39:44Z

On Mon, Oct 02, 2017 at 11:53:12PM +0100, Matt Fleming wrote:
> On Wed, 27 Sep, at 01:58:20PM, Rik van Riel wrote:
> >
> > I like the simplicity of your approach! I hope it does not break
> > stuff like netperf...
> >
> > I have been working on the patch below, which is much less optimistic
> > about when to do an affine wakeup than before.
>
> Running netperf for this patch and Peter's patch shows that Peter's
> comes out on top, with scores pretty close to v4.12 in most places on
> my 2-NUMA node 48-CPU Xeon box.
>
> I haven't dug any further into why v4.13-peterz+ is worse than v4.12,
> but I will next week.

So I was waiting for Rik, who promised to run a bunch of NUMA workloads
over the weekend.

The trivial thing regresses a wee bit on the overloaded case, I've not
yet tried to fix it.