Re: [PATCH v2 2/2] sched/topology: Optimize topology_span_sane()

From: Kyle Meyer
Date: Thu Apr 11 2024 - 17:55:59 EST


On Thu, Apr 11, 2024 at 01:38:46PM +0300, Andy Shevchenko wrote:
> On Wed, Apr 10, 2024 at 04:33:11PM -0500, Kyle Meyer wrote:
> > Optimize topology_span_sane() by removing duplicate comparisons.
> >
> > Since topology_span_sane() is called inside of for_each_cpu(), each
> > pervious CPU has already been compared against every other CPU. The
>
> previous

Thank you for pointing that out. Should I send an updated version or can
a maintainer correct my mistake?

> > current CPU only needs to be compared against higher-numbered CPUs.
> >
> > The total number of comparisons is reduced from N * (N - 1) to
> > N * (N - 1) / 2 on each non-NUMA scheduling domain level.
>
> Thank you, now it makes sense.

Thanks,
Kyle Meyer