Re: [PATCH v1 0/4] mm: move vma_(kernel|mmu)_pagesize() out of hugetlb.c

From: David Hildenbrand (Arm)

Date: Fri Mar 06 2026 - 08:14:06 EST


On 3/6/26 12:19, Lorenzo Stoakes (Oracle) wrote:
> On Fri, Mar 06, 2026 at 11:13:41AM +0000, Pedro Falcato wrote:
>> On Fri, Mar 06, 2026 at 11:15:56AM +0100, David Hildenbrand (Arm) wrote:
>>> Looking into vma_(kernel|mmu)_pagesize(), I realized that there is one
>>> scenario where DAX would not do the right thing when the kernel is
>>> not compiled with hugetlb support.
>>>
>>> Without hugetlb support, vma_(kernel|mmu)_pagesize() will always return
>>> PAGE_SIZE instead of using the ->pagesize() result provided by dax-device
>>> code.
>>>
>>> Fix that by moving vma_kernel_pagesize() to core MM code, where it belongs.
>>> I don't think this is stable material, but am not 100% sure.
>>>
>>> Also, move vma_mmu_pagesize() while at it. Remove the unnecessary hugetlb.h
>>> inclusion from KVM code.
>>>
>>> Cross-compiled heavily.
>>>
>>> Cc: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
>>> Cc: Madhavan Srinivasan <maddy@xxxxxxxxxxxxx>
>>> Cc: Nicholas Piggin <npiggin@xxxxxxxxx>
>>> Cc: Michael Ellerman <mpe@xxxxxxxxxxxxxx>
>>> Cc: "Christophe Leroy (CS GROUP)" <chleroy@xxxxxxxxxx>
>>> Cc: Muchun Song <muchun.song@xxxxxxxxx>
>>> Cc: Oscar Salvador <osalvador@xxxxxxx>
>>> Cc: Lorenzo Stoakes <ljs@xxxxxxxxxx>
>>> Cc: "Liam R. Howlett" <Liam.Howlett@xxxxxxxxxx>
>>> Cc: Vlastimil Babka <vbabka@xxxxxxxxxx>
>>> Cc: Mike Rapoport <rppt@xxxxxxxxxx>
>>> Cc: Suren Baghdasaryan <surenb@xxxxxxxxxx>
>>> Cc: Michal Hocko <mhocko@xxxxxxxx>
>>> Cc: Jann Horn <jannh@xxxxxxxxxx>
>>> Cc: Pedro Falcato <pfalcato@xxxxxxx>
>>> Cc: Paolo Bonzini <pbonzini@xxxxxxxxxx>
>>> Cc: Dan Williams <dan.j.williams@xxxxxxxxx>
>>
>> Although we all love less mail, FYI it seems like this didn't work properly
>> for the patches (no CC's on there).
>>
>> Did you try git-email --cc-cover?
>
> Yeah I noticed this also :>) Assumed it was a new way of doing things somehow?
> :P

"--cc-cover" is apparently not the git default on my new machine.

"See, I CCed you, I totally did not try to sneak something in. Oh, I
messed up my tooling, stupid me ...". :)

--
Cheers,

David