Re: [PATCH 00/33] arm_mpam: Add basic mpam driver

Carl Worth
2025-11-11T00:45:38Z

Ben Horgan <ben.horgan@arm.com> writes:
> Yes, the driver does barely anything without a requestor.
...
> Thanks for the quick response and testing.

Sure thing!

> I've just responded to the cover letter with a branch containing the
> rest of the driver. (Just so it's not hidden in this thread) It's
> https://git.kernel.org/pub/scm/linux/kernel/git/morse/linux.git/log/?h=mpam/snapshot/v6.18-rc4

Yes. I saw that. That's very helpful, so thank you!

> With that, you should be able to enable all usable PARTID and PMG, mount
> resctrl, add tasks/cpus to resctrl control groups, run benchmarks to
> check that the controls are respected and check that the monitors give
> expected values.

Indeed. I now get:

MPAM enabled with 256 PARTIDs and 2 PMGs

And I have mounted resctrl, added cpus to resctrl control groups, and
then manipulated the L3 cache bitmap control and verified that
benchmarks respond as expected to changes to the control.

I was going to report that I am encountering an unexpected alignment
fault in one of the KUNIT tests, but then I realized that that's in
test_get_mba_granularity which comes in as part of the snapshot, and is
not part of the code that is submitted here. So I'll continue to
invetigate that, but that need not delay the code of interest in the
current series.

Given all of that, for the series:

Tested-by: Carl Worth <carl@os.amperecomputing.com>

-Carl