Re: [PATCH] mm/page_vma_mapped: guard check_pmd() with CONFIG_TRANSPARENT_HUGEPAGE

[David Hildenbrand (Arm)]

On 6/25/26 15:45, Lorenzo Stoakes wrote:
> On Wed, Jun 24, 2026 at 08:23:59AM +0000, Wei Yang wrote:
>> The kernel test robot reported a build failure on the parisc architecture
>> when expanding HPAGE_PMD_NR in check_pmd().
> 
> Let me first say that I absolutely hate that we continue to support museum
> piece architectures to the point that we have to make changes in core code
> to accommodate them.

I wonder why we shouldn't be able to trigger that on other archs with
!CONFIG_TRANSPARENT_HUGEPAGE ?

I think the code just relies on pmd_trans_huge() == false, and consequently
check_pmd will get compiled out completely.

Now, the report was against Wei's new patch.

There is *nothing* to be fixed for existing code.


Fixes: 2aff7a4755be ("mm: Convert page_vma_mapped_walk to work on PFNs")

is just wrong?

-- 
Cheers,

David