Re: [PATCH v3 27/47] arm_mpam: resctrl: Add support for 'MB' resource

Jonathan Cameron
2026-01-13T15:06:23Z

On Mon, 12 Jan 2026 16:58:54 +0000
Ben Horgan <ben.horgan@arm.com> wrote:

> From: James Morse <james.morse@arm.com>
>
> resctrl supports 'MB', as a percentage throttling of traffic somewhere
> after the L3. This is the control that mba_sc uses, so ideally the class
> chosen should be as close as possible to the counters used for mba_local.
>
> MB's percentage control should be backed either with the fixed point
> fraction MBW_MAX or bandwidth portion bitmaps. The bandwidth portion
> bitmaps is not used as its tricky to pick which bits to use to avoid
> contention, and may be possible to expose this as something other than a
> percentage in the future.
>
> CC: Zeng Heng <zengheng4@huawei.com>
> Co-developed-by: Dave Martin <Dave.Martin@arm.com>
> Signed-off-by: Dave Martin <Dave.Martin@arm.com>
> Signed-off-by: James Morse <james.morse@arm.com>>
> Signed-off-by: Ben Horgan <ben.horgan@arm.com>
Reviewed-by: Jonathan Cameron <jonathan.cameron@huawei.com>