Re: [PATCH v3 6/6] mm/hugetlb: add folio_hstate()

[Mike Kravetz]

On 09/08/22 12:37, Sidhartha Kumar wrote:
> Helper function to retrieve hstate information from a hugetlb folio.
> 
> Signed-off-by: Sidhartha Kumar <sidhartha.kumar@xxxxxxxxxx>
> Reported-by: kernel test robot <lkp@xxxxxxxxx>
> ---
>  include/linux/hugetlb.h | 14 ++++++++++++--
>  mm/migrate.c            |  2 +-
>  2 files changed, 13 insertions(+), 3 deletions(-)

Thanks,  Someday we will be able to remove page_hstate.

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

> 
> diff --git a/include/linux/hugetlb.h b/include/linux/hugetlb.h
> index 0bcaca694ab7..f59e8fb3f937 100644
> --- a/include/linux/hugetlb.h
> +++ b/include/linux/hugetlb.h
> @@ -850,10 +850,15 @@ static inline pte_t arch_make_huge_pte(pte_t entry, unsigned int shift,
>  }
>  #endif
>  
> +static inline struct hstate *folio_hstate(struct folio *folio)
> +{
> +	VM_BUG_ON_FOLIO(!folio_test_hugetlb(folio), folio);
> +	return size_to_hstate(folio_size(folio));
> +}
> +
>  static inline struct hstate *page_hstate(struct page *page)
>  {
> -	VM_BUG_ON_PAGE(!PageHuge(page), page);
> -	return size_to_hstate(page_size(page));
> +	return folio_hstate(page_folio(page));
>  }
>  
>  static inline unsigned hstate_index_to_shift(unsigned index)
> @@ -1057,6 +1062,11 @@ static inline struct hstate *hstate_vma(struct vm_area_struct *vma)
>  	return NULL;
>  }
>  
> +static inline struct hstate *folio_hstate(struct folio *folio)
> +{
> +	return NULL;
> +}
> +
>  static inline struct hstate *page_hstate(struct page *page)
>  {
>  	return NULL;
> diff --git a/mm/migrate.c b/mm/migrate.c
> index 6a1597c92261..55392a706493 100644
> --- a/mm/migrate.c
> +++ b/mm/migrate.c
> @@ -1589,7 +1589,7 @@ struct page *alloc_migration_target(struct page *page, unsigned long private)
>  		nid = folio_nid(folio);
>  
>  	if (folio_test_hugetlb(folio)) {
> -		struct hstate *h = page_hstate(&folio->page);
> +		struct hstate *h = folio_hstate(folio);
>  
>  		gfp_mask = htlb_modify_alloc_mask(h, gfp_mask);
>  		return alloc_huge_page_nodemask(h, nid, mtc->nmask, gfp_mask);
> -- 
> 2.31.1