Re: [PATCH 3/7] x86/resctrl: Introduce sdciae_capable in rdt_resource

Reinette Chatre
2024-10-16T18:31:31Z

Hi Babu,

On 10/16/24 9:46 AM, Moger, Babu wrote:
> On 10/16/24 10:54, Reinette Chatre wrote:
>> On 10/15/24 1:40 PM, Moger, Babu wrote:
>>> On 9/19/24 10:33, Reinette Chatre wrote:
>>>> On 9/18/24 11:22 AM, Moger, Babu wrote:
>>>>> On 9/18/24 10:27, Moger, Babu wrote:
>>>>>> On 9/13/24 15:45, Reinette Chatre wrote:
>>>>>>> On 8/16/24 9:16 AM, Babu Moger wrote:
>>>>>>>> Detect SDCIAE`(L3 Smart Data Cache Injection Allocation Enforcement)
>>>>>>>
>>>>>>> (stray ` char)
>>>>>>
>>>>>> Sure.
>>>>>>
>>>>>>>
>>>>>>>> feature and initialize sdciae_capable.
>>>>>>>
>>>>>>> (This is a repeat of the discussion we had surrounding the ABMC feature.)
>>>>>>>
>>>>>>> By adding "sdciae_capable" to struct rdt_resource the "sdciae" feature
>>>>>>> becomes a resctrl fs feature. Any other architecture that has a "similar
>>>>>>> but perhaps not identical feature to AMD's SDCIAE" will be forced to also
>>>>>>> call it "sdciae" ... sdciae seems like a marketing name to me and resctrl
>>>>>>> needs something generic that could later be built on (if needed) by other
>>>>>>> architectures.
>>>>>>
>>>>>> How about "cache_inject_capable" ?
>>>>>>
>>>>>> This seems generic. I will change the description also.
>>>>>>
>>>>>
>>>>> Basically, this feature reserves specific CLOS for SDCI cache.
>>>>>
>>>>> We can also name "clos_reserve_capable".
>>>>
>>>> Naming is always complicated. I think we should try to stay away from
>>>> "clos" in a generic name since that creates problem when trying to
>>>> apply it to Arm and is very specific to how AMD implements this
>>>> feature. "cache_inject_capable" does sound much better to me ...
>>>> it also looks like this may be more appropriate as a property
>>>> of struct resctrl_cache?
>>>
>>> Coming back to this again, I feel 'cache_inject_capable' is kind of very
>>> generic. Cache injection term is used very generically everywhere.
>>>
>>> Does 'cache_reserve_capable" sound good ? This is inside the resctrl
>>> subsystem. We know what it is referring to.
>>>
>>
>> Since this is inside resctrl "cache_reserve_capable" sounds like existing
>> CAT to me. Could it help if the term "io" appears in the name? Something like
>> "io_reserve_capable"? When this is a member of struct resctrl_cache it should
>> be implicit that it refers to the cache.
>
> Yea. Naming is difficult.
>
> How about "io_alloc_capable"?
>

Sounds good to me, thank you.

Reinette