Re: [PATCH v3 updated] mm/demotion: Expose memory tier details via sysfs

[Aneesh Kumar K V]

On 9/2/22 11:10 AM, Huang, Ying wrote:
> Aneesh Kumar K V <aneesh.kumar@xxxxxxxxxxxxx> writes:
> 
>> On 9/2/22 10:39 AM, Wei Xu wrote:
>>> On Thu, Sep 1, 2022 at 5:33 PM Huang, Ying <ying.huang@xxxxxxxxx> wrote:
>>>>
>>>> Aneesh Kumar K V <aneesh.kumar@xxxxxxxxxxxxx> writes:
>>>>
>>>>> On 9/1/22 12:31 PM, Huang, Ying wrote:
>>>>>> "Aneesh Kumar K.V" <aneesh.kumar@xxxxxxxxxxxxx> writes:
>>>>>>
>>>>>>> This patch adds /sys/devices/virtual/memory_tiering/ where all memory tier
>>>>>>> related details can be found. All allocated memory tiers will be listed
>>>>>>> there as /sys/devices/virtual/memory_tiering/memory_tierN/
>>>>>>>
>>>>>>> The nodes which are part of a specific memory tier can be listed via
>>>>>>> /sys/devices/virtual/memory_tiering/memory_tierN/nodes
>>>>>>
>>>>>> I think "memory_tier" is a better subsystem/bus name than
>>>>>> memory_tiering.  Because we have a set of memory_tierN devices inside.
>>>>>> "memory_tier" sounds more natural.  I know this is subjective, just my
>>>>>> preference.
>>>>>>
>>
>>
>> I missed replying to this earlier. I will keep memory_tiering as subsystem name in v4 
>> because we would want it to a susbsystem where all memory tiering related details can be found
>> including memory type in the future. This is as per discussion 
>>
>> https://lore.kernel.org/linux-mm/CAAPL-u9TKbHGztAF=r-io3gkX7gorUunS2UfstudCWuihrA=0g@xxxxxxxxxxxxxx
> 
> I don't think that it's a good idea to mix 2 types of devices in one
> subsystem (bus).  If my understanding were correct, that breaks the
> driver core convention.
> 

All these are virtual devices .I am not sure i follow what you mean by 2 types of devices.
memory_tiering is a subsystem that represents all the details w.r.t memory tiering. It shows
details of memory tiers and can possibly contain details of different memory types .

-aneesh