Re: [PATCH v4 1/9] hugetlb: Pass vma into huge_pte_alloc()

[Mike Kravetz]

On 1/28/21 3:42 PM, Axel Rasmussen wrote:
> From: Peter Xu <peterx@xxxxxxxxxx>
> 
> It is a preparation work to be able to behave differently in the per
> architecture huge_pte_alloc() according to different VMA attributes.
> 
> Signed-off-by: Peter Xu <peterx@xxxxxxxxxx>
> [axelrasmussen@xxxxxxxxxx: fixed typo in arch/mips/mm/hugetlbpage.c]
> Signed-off-by: Axel Rasmussen <axelrasmussen@xxxxxxxxxx>
> ---
>  arch/arm64/mm/hugetlbpage.c   | 2 +-
>  arch/ia64/mm/hugetlbpage.c    | 3 ++-
>  arch/mips/mm/hugetlbpage.c    | 4 ++--
>  arch/parisc/mm/hugetlbpage.c  | 2 +-
>  arch/powerpc/mm/hugetlbpage.c | 3 ++-
>  arch/s390/mm/hugetlbpage.c    | 2 +-
>  arch/sh/mm/hugetlbpage.c      | 2 +-
>  arch/sparc/mm/hugetlbpage.c   | 2 +-
>  include/linux/hugetlb.h       | 2 +-
>  mm/hugetlb.c                  | 6 +++---
>  mm/userfaultfd.c              | 2 +-
>  11 files changed, 16 insertions(+), 14 deletions(-)

Sorry for the delay in reviewing.

huge_pmd_share() will do a find_vma() to get the vma.  So, it would be
'possible' to not add an extra argument to huge_pmd_alloc() and simply
do the uffd_disable_huge_pmd_share() check inside vma_shareable.  This
would reduce the amount of modified code, but would not be as efficient.
I prefer passing the vma argument as is done here.

Reviewed-by: Mike Kravetz <mike.kravetz@xxxxxxxxxx>

-- 
Mike Kravetz