Re: [PATCH v15 12/34] fs/resctrl: Introduce mbm_cntr_cfg to track assignable counters per domain

[Reinette Chatre <reinette.chatre@intel.com>]

Hi Babu,

On 7/8/25 3:17 PM, Babu Moger wrote:
> The "mbm_event" counter assignment mode allows users to assign a hardware
> counter to an RMID, event pair and monitor bandwidth usage as long as it is
> assigned.  The hardware continues to track the assigned counter until it is
> explicitly unassigned by the user. Counters are assigned/unassigned at
> monitoring domain level.
> 
> Manage a monitoring domain's hardware counters using a per monitoring
> domain array of struct mbm_cntr_cfg that is indexed by the hardware
> counter ID. A hardware counter's configuration contains the MBM event
> ID and points to the monitoring group that it is assigned to, with a NULL
> pointer meaning that the hardware counter is available for assignment.
> 
> There is no direct way to determine which hardware counters are assigned
> to a particular monitoring group. Check every entry of every hardware
> counter configuration array in every monitoring domain to query which
> MBM events of a monitoring group is tracked by hardware. Such queries are
> acceptable because of a very small number of assignable counters (32
> to 64).
> 
> Suggested-by: Peter Newman <peternewman@google.com>
> Signed-off-by: Babu Moger <babu.moger@amd.com>
> ---

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

Reinette