Re: [PATCH mm-unstable 8/8] mm/hugetlb: convert demote_free_huge_page to folios

Sidhartha Kumar
2023-01-09T21:00:36Z

On 1/9/23 2:01 PM, John Hubbard wrote:
> On 1/9/23 10:23, Mike Kravetz wrote:
>>>>>> No problems with the code, but I am not in love with the name
>>>>>> subfolio.
>>>>>> I know it is patterned after 'subpage'.  For better or worse, the
>>>>>> term
>>>>>> subpage is used throughout the kernel.  This would be the first
>>>>>> usage of
>>>>>> the term 'subfolio'.
>>>>>>
>>>>>> Matthew do you have any comments on the naming?  It is local to
>>>>>> hugetlb,
>>>>>> but I would hate to see use of the term subfolio based on its
>>>>>> introduction
>>>>>> here.
>>>>>
>>>>> I'm really not a fan of it either.  I intended to dive into this patch
>>>>> and understand the function it's modifying, in the hopes of suggesting
>>>>> a better name and/or method.
>>>>
>>>> At a high level, this routine is splitting a very large folio (1G for
>>>> example) into multiple large folios of a smaller size (512 2M folios
>>>> for
>>>> example).  The loop is iterating through the very large folio at
>>>> increments of the smaller large folio.  subfolio (previously
>>>> subpage) is
>>>> used to point to the smaller large folio within the loop.
>>>>
>>> If folio does not need to be part of the variable name, how about
>>> something
>>> like 'demote_target'? The prep call inside the loop would then look
>>> like:
>>>
>>> prep_new_hugetlb_folio(target_hstate, demote_target, nid);
>>>
>>> so it is still clear that demote_target is a folio. A more concise
>>> version
>>> could also be 'demote_dst' but that seems more ambiguous than target.
>>
>> I am OK with that naming.  Primary concern was the introduction of the
>> term subfolio.
>
> How about one of these:
>
>     smaller_folio
>     inner_folio
>
> Those are more self-explanatory, while still avoiding "subfolio".
>
I would be fine with inner_folio.

Thanks,
Sidhartha Kumar

> thanks,