Re: [PATCH v3 0/8] arm_mpam: resctrl: Separate MPAM domains

[Ben Horgan <ben.horgan@arm.com>]

Hi Reinette,

On 10/11/2026 04:19, Reinette Chatre wrote:
> Thank you very much to Ben, Jinjie, and Shaopeng for reviewing and testing RFC v2.
> 
> Changes since RFC v2:
>   - RFC v2: https://lore.kernel.org/lkml/cover.1792443633.git.reinette.chatre@intel.com/
>   - Patch 1 is new. It adds find_mbwu_mon_comp() to replace the duplicate
>     code found in resctrl_arch_cntr_read() and resctrl_arch_reset_cntr(),
>     as suggested by Jinjie.
>   - WARN when domain allocation fails. (Ben)
>   - Squash three patches into the patches they build on. (Ben)
>   - Move "Require a component for each monitoring event" ahead of the
>     structure split so the check it adds precedes its first user.
>   - Fix the mpam_resctrl_get_mon_domain_from_cpu() function comment that
>     still referred to the control component.
>   - Add tags from Jinjie and Ben.
>   - Please see the individual patches for their detailed changelogs.
> 
> Changes since RFC v1:
>   - RFC v1: https://lore.kernel.org/lkml/85ca29e89eacf12cfa7071249419e7cadb8f0691.1788220029.git.reinette.chatre@intel.com/
>   - Give each type of domain its own structure instead of duplicating the
>     shared one, set up each domain independently instead of undoing one
>     domain when setting up the other fails, add additional verification
>     checks.
> 
> The MPAM driver represents a resctrl domain with a single structure,
> struct mpam_resctrl_dom, that holds both a control domain and a
> monitoring domain. On a system that supports both allocation and
> monitoring, one instance is created for each domain and its two
> domains are added to the resource's control and monitoring domain
> lists.

Thank you for this respin.

To avoid any confusion for others I mention here that the 'MPAM domains' mentioned here are the MPAM
driver representations of resctrl domains and *not* related to the MPAM feature
FEAT_MPAM_MSC_DOMAINS. There is currently no support for FEAT_MPAM_MSC_DOMAINS in the MPAM driver.

Thanks,

Ben