Re: [PATCH v2 0/2] mm/mprotect: micro-optimization work

[Luke Yang <luyang@redhat.com>]

On Wed, Apr 1, 2026 at 10:11 AM Pedro Falcato <pfalcato@suse.de> wrote:
>
> On Mon, Mar 30, 2026 at 03:55:51PM -0400, Luke Yang wrote:
> > Hi Pedro,
> >
> > Thanks for working on this. I just wanted to share that we've created a
> > test kernel with your patches and tested on the following CPUs:
> >
> > --- aarch64 ---
> > Ampere Altra
> > Ampere Altra Max
> >
> > --- x86_64 ---
> > AMD EPYC 7713
> > AMD EPYC 7351
> > AMD EPYC 7542
> > AMD EPYC 7573X
> > AMD EPYC 7702
> > AMD EPYC 9754
> > Intel Xeon Gold 6126
> > Into Xeon Gold 6330
> > Intel Xeon Gold 6530
> > Intel Xeon Platinum 8351N
> > Intel Core i7-6820HQ
> >
> > --- ppc64le ---
> > IBM Power 10
> >
> > On average, we see improvements ranging from a minimum of 5% to a
> > maximum of 55%, with most improvements showing around a 25% speed up in
> > the libmicro/mprot_tw4m micro benchmark.
>
> Nice! Thanks for the tests. I'm wondering, what CPU saw 5% and what CPU
> saw 55%? Or was it just inter-run variance?
>
> --
> Pedro
>

5% -> Ampere Altra Max
55% -> Ampere Altra

Personally, I can't conclude at the moment if this is just inter-run
variance. However, let me re-run the tests a few times on these two
machines to see if this is consistent.

Luke