Re: [PATCH v4 0/2] mm: add per-order mTHP alloc and swpout counters

[Ryan Roberts]

On 05/04/2024 23:04, Barry Song wrote:
> On Sat, Apr 6, 2024 at 9:11 AM Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> wrote:
>>
>> On Fri,  5 Apr 2024 23:27:02 +1300 Barry Song <21cnbao@xxxxxxxxx> wrote:
>>
>>> The patchset introduces a framework to facilitate mTHP counters, starting
>>> with the allocation and swap-out counters. Currently, only four new nodes
>>> are appended to the stats directory for each mTHP size.
>>>
>>> /sys/kernel/mm/transparent_hugepage/hugepages-<size>/stats
>>>       anon_alloc
>>>       anon_alloc_fallback
>>>       anon_swpout
>>>       anon_swpout_fallback
>>
>> Please let's get these documented?
> 
> Sure, I will do it.
> 
> Furthermore, after careful consideration, I suggest renaming anon_alloc to
> anon_fault_alloc and anon_alloc_fallback to anon_fault_fallback. This
> renaming is consistent with the naming convention observed in
> thp_fault_alloc and thp_fault_fallback in vmstat. Additionally, this
> modification will facilitate the handling of large folio swap-ins.
> 
> /sys/kernel/mm/transparent_hugepage/hugepages-<size>/stats
>            anon_fault_alloc,
>            anon_fault_fallback,
>            anon_swpin_alloc,
>            anon_swpin_fallback,
> 
> Otherwise, without this renaming, it would be difficult to
> differentiate fault_alloc
> from swpin_alloc.
> 
> Hi David, Ryan,
> I would also appreciate your input on the modification I am considering.

Yes, this makes sense to me!

> 
>> Documentation/admin-guide/mm/transhuge.rst seems to be the place, and
>> under Documentation/ABI.
> 
> Thanks
> Barry