Re: [PATCH v5 5/7] fs/resctrl: Continue counter allocation after failure

From: Reinette Chatre

Date: Mon May 04 2026 - 12:02:17 EST


Hi Ben,

On 4/28/26 6:04 AM, Ben Horgan wrote:
> In mbm_event mode, with mbm_assign_on_mkdir set to 1, when a user creates a
> new CTRL_MON or MON group resctrl attempts to allocate counters for each of
> the supported MBM events on each resctrl domain. As counters are limited,
> such allocation may fail and when it does counter allocations for the
> remaining domains are skipped even if the domains have available counters.
>
> Since a counter allocation failure may result in counter allocation being
> skipped on other domains the user needs to view the resource group's
> mbm_L3_assignments files to get an accurate view of counter assignment in a

nit: files -> file

> new resource group and then manually create counters in the skipped domains
> with available counters.
>
> Writes to mbm_L3_assignments using the wildcard format, <event>:*=e, also
> skip counter allocation in other domains after a counter allocation
> failure.
>
> When handling a request to create counters in all domains it is unnecessary
> for a counter allocation in one domain to prevent counter allocation in
> other domains. Always attempt to allocate all the counters requested.
>
> Signed-off-by: Ben Horgan <ben.horgan@xxxxxxx>
> ---

Reviewed-by: Reinette Chatre <reinette.chatre@xxxxxxxxx>

Reinette