Re: [RFC PATCH v2 1/5] mm: make HPAGE_PxD_{SHIFT,MASK,SIZE} always available

[Andrea Arcangeli]

On Fri, Jul 10, 2020 at 05:57:46PM +0100, Matthew Wilcox wrote:
> btw, using the hpage_ prefix already caused one problem in the hugetlb
> code:
> 
> https://lore.kernel.org/linux-mm/20200629185003.97202-1-mike.kravetz@xxxxxxxxxx/
> 
> I'd suggest we rename these to THP_PMD_* and THP_PUD_* to make it clear
> they're only for the THP case.

The confusion seem to have happened only about hpage_nr_pages not
about HPAGE_PMD_*. It's just the hpage_ prefix alone that is commonly
used by hugetlbfs only and so it's not surprising it caused confusion.

So I certainly agree hpage_nr_pages would better be renamed to
something more THP specific (either hpage_pmd_nr_pages or
trans_huge_nr_pages or as you wish), but HPAGE_PMD_ don't look too
confusing about the fact it's only for the THP case since the non-THP
case won't necessarily care about PMDs.

Thanks,
Andrea