Hi James,
On 2/21/25 10:07 AM, James Morse wrote:
> Hi Babu,
>
> On 22/01/2025 20:20, Babu Moger wrote:
>> In mbm_cntr_assign mode hardware counters are assigned/unassigned to an
>> MBM event of a monitor group. Hardware 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.
>
>> diff --git a/include/linux/resctrl.h b/include/linux/resctrl.h
>> index 511cfce8fc21..9a54e307d340 100644
>> --- a/include/linux/resctrl.h
>> +++ b/include/linux/resctrl.h
>> @@ -94,6 +94,18 @@ struct rdt_ctrl_domain {
>> u32 *mbps_val;
>> };
>>
>> +/**
>> + * struct mbm_cntr_cfg - assignable counter configuration
>> + * @evtid: MBM event to which the counter is assigned. Only valid
>> + * if @rdtgroup is not NULL.
>> + * @rdtgroup: resctrl group assigned to the counter. NULL if the
>> + * counter is free.
>> + */
>> +struct mbm_cntr_cfg {
>> + enum resctrl_event_id evtid;
>> + struct rdtgroup *rdtgrp;
>> +};
>
> struct rdtgroup here suggests this shouldn't be something the arch code is touching.
>
> If its not needed by any arch specific code, (I couldn't find a resctrl_arch helper that
> takes this) - could it be moved to resctrl's internal.h.
>
> (If this does need to be visible to the arch code, one option would be to replace rdtgroup
> with the closid/rmid, and a valid flag so that memset() continues to reset these entries)
>
Thank you for catching this!
Reinette
