Re: [PATCH v6 0/2] fs/resctrl: Add "*" shorthand to set io_alloc CBM for all domains

[Moger, Babu]

Looks good to me.

On 3/24/2026 7:11 PM, Aaron Tomlin wrote:
> Hi Babu, Tony, Reinette,
>
> This series addresses two limitations in the fs/resctrl io_alloc interface:
> inconsistent error reporting and the lack of a mechanism for bulk
> configuration.
>
> The last_cmd_status file is intended to report details about the most
> recent resctrl filesystem operation, specifically to aid in diagnosing
> failures. However, when parsing io_alloc_cbm, if a user provides a domain ID
> that does not exist in the resource, the operation fails with -EINVAL without
> updating last_cmd_status. This results in inconsistent behaviour where
> the system call returns an error, but last_cmd_status misleadingly reports
> "ok", leaving the user unaware that the failure was caused by an invalid
> domain ID. Patch 1 addresses this by writing an error message to
> last_cmd_status when the target domain ID cannot be found.
>
> Configuring the io_alloc_cbm interface requires an explicit
> domain ID for each cache domain. On systems with high core counts and
> numerous cache clusters, this requirement becomes cumbersome for automation
> and management tasks that aim to apply a uniform policy. Patch 2
> introduces a wildcard domain ID selector "*" for the io_alloc_cbm
> interface. This enables users to set the same Capacity Bitmask (CBM)
> across all cache domains in a single operation.
>
> Please let me know your thoughts.

Tested-by: Babu Moger <babu.moger@xxxxxxx>
Reviewed-by: Babu Moger <babu.moger@xxxxxxx>