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

Lorenzo Stoakes (Oracle)
2026-03-09T13:42:46Z

On Fri, Mar 06, 2026 at 02:12:50PM +0100, David Hildenbrand (Arm) wrote:
> 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@linux-foundation.org>
> >>> Cc: Madhavan Srinivasan <maddy@linux.ibm.com>
> >>> Cc: Nicholas Piggin <npiggin@gmail.com>
> >>> Cc: Michael Ellerman <mpe@ellerman.id.au>
> >>> Cc: "Christophe Leroy (CS GROUP)" <chleroy@kernel.org>
> >>> Cc: Muchun Song <muchun.song@linux.dev>
> >>> Cc: Oscar Salvador <osalvador@suse.de>
> >>> Cc: Lorenzo Stoakes <ljs@kernel.org>
> >>> Cc: "Liam R. Howlett" <Liam.Howlett@oracle.com>
> >>> Cc: Vlastimil Babka <vbabka@kernel.org>
> >>> Cc: Mike Rapoport <rppt@kernel.org>
> >>> Cc: Suren Baghdasaryan <surenb@google.com>
> >>> Cc: Michal Hocko <mhocko@suse.com>
> >>> Cc: Jann Horn <jannh@google.com>
> >>> Cc: Pedro Falcato <pfalcato@suse.de>
> >>> Cc: Paolo Bonzini <pbonzini@redhat.com>
> >>> Cc: Dan Williams <dan.j.williams@intel.com>
> >>
> >> 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 ...". :)

;)

Wasn't aware of that option actually, handy!

>
> --
> Cheers,
>
> David

Cheers, Lorenzo