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

From: Mike Rapoport <[email-masked]>
Date: Fri, 6 Mar 2026 17:30:45 +0200

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 <[email-masked]>
> Cc: Madhavan Srinivasan <[email-masked]>
> Cc: Nicholas Piggin <[email-masked]>
> Cc: Michael Ellerman <[email-masked]>
> Cc: "Christophe Leroy (CS GROUP)" <[email-masked]>
> Cc: Muchun Song <[email-masked]>
> Cc: Oscar Salvador <[email-masked]>
> Cc: Lorenzo Stoakes <[email-masked]>
> Cc: "Liam R. Howlett" <[email-masked]>
> Cc: Vlastimil Babka <[email-masked]>
> Cc: Mike Rapoport <[email-masked]>
> Cc: Suren Baghdasaryan <[email-masked]>
> Cc: Michal Hocko <[email-masked]>
> Cc: Jann Horn <[email-masked]>
> Cc: Pedro Falcato <[email-masked]>
> Cc: Paolo Bonzini <[email-masked]>
> Cc: Dan Williams <[email-masked]>
> 
> David Hildenbrand (Arm) (4):
>   mm: move vma_kernel_pagesize() from hugetlb to mm.h
>   mm: move vma_mmu_pagesize() from hugetlb to vma.c
>   KVM: remove hugetlb.h inclusion
>   KVM: PPC: remove hugetlb.h inclusion
> 
>  arch/powerpc/kvm/book3s_hv.c |  1 -
>  include/linux/hugetlb.h      | 14 --------------
>  include/linux/mm.h           | 22 ++++++++++++++++++++++
>  mm/hugetlb.c                 | 28 ----------------------------
>  mm/vma.c                     | 21 +++++++++++++++++++++
>  virt/kvm/kvm_main.c          |  1 -
>  6 files changed, 43 insertions(+), 44 deletions(-)

For the series:
 
Acked-by: Mike Rapoport (Microsoft) <[email-masked]>

> base-commit: f75825cdfc4c5477cffcfd2cafa4e5ce5aa67f13
> -- 
> 2.43.0
> 

-- 
Sincerely yours,
Mike.