Re: [PATCH v11 18/23] x86/resctrl: Report "Unassigned" for MBM events in mbm_cntr_assign mode

[Moger, Babu]

Hi Reinette,

On 2/6/25 12:04, Reinette Chatre wrote:
> Hi Babu,
> 
> On 1/22/25 12:20 PM, Babu Moger wrote:
>> In mbm_cntr_assign mode, the hardware counter should be assigned to read
>> the MBM events.
>>
>> Report 'Unassigned' in case the user attempts to read the events without
>> assigning the counter.
>>
>> Signed-off-by: Babu Moger <babu.moger@xxxxxxx>
>> ---
> 
>> diff --git a/Documentation/arch/x86/resctrl.rst b/Documentation/arch/x86/resctrl.rst
>> index 99cae75559b0..072b15550ff7 100644
>> --- a/Documentation/arch/x86/resctrl.rst
>> +++ b/Documentation/arch/x86/resctrl.rst
>> @@ -431,6 +431,16 @@ When monitoring is enabled all MON groups will also contain:
>>  	for the L3 cache they occupy). These are named "mon_sub_L3_YY"
>>  	where "YY" is the node number.
>>  
>> +	When supported the mbm_cntr_assign mode allows users to assign a
> 
> Same comment as previous version.

Sorry about that.

"mbm_cntr_assign mode allows users to assign a"


> 
>> +	counter to mon_hw_id, event pair enabling bandwidth monitoring for
>> +	as long as the counter remains assigned. The hardware will continue
>> +	tracking the assigned mon_hw_id until the user manually unassigns
>> +	it, ensuring that counters are not reset during this period. With
>> +	a limited number of counters, the system may run out of assignable
>> +	counters. In that case, MBM event counters will return 'Unassigned'
>> +	when the event is read. Users must manually assign a counter to read
>> +	the events.
>> +
>>  "mon_hw_id":
>>  	Available only with debug option. The identifier used by hardware
>>  	for the monitor group. On x86 this is the RMID.
> 
> Reinette
> 

-- 
Thanks
Babu Moger