Re: [PATCH v5 0/3] x86,fs/resctrl,arm_mpam: Factor MBA parse-time conversion to be per-arch

From: Ben Horgan

Date: Mon Sep 07 2026 - 06:45:19 EST


Hi Boris, Reinette,

On 04/09/2026 18:36, Borislav Petkov wrote:
> On Thu, Sep 03, 2026 at 08:37:51PM -0700, Borislav Petkov wrote:
>> Lemme have a look.
>
> Sashiko has comments:
>
> https://sashiko.dev/#/patchset/20260709093111.367851-1-ben.horgan%40arm.com
>
> Please address them: if valid, fix them, if not, explain why they don't need
> to be fixed.
>
> Thx.
>

Regarding the first Sashiko comment.

The documentation change in patch 3 includes the sentence:

"
The allocated bandwidth percentage is rounded up to the next control step available on the
hardware.
"

Sashiko rightly objects to the "rounded up". For MPAM systems this can be up or down and we test in
test_mpam_resctrl.c:test_percent_to_max_rounding() that it isn't too biased to rounding one way or
the other.

How about replacing "rounded up" with "rounded up or down" so that the sentence becomes:

"
The allocated bandwidth percentage is rounded up or down to the next control step available on the
hardware.
"

What do you think? Should I respin the series with this alteration?


Thanks,

Ben