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

Reinette Chatre
2024-10-16T15:54:26Z

Hi Babu,

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.

Reinette