Re: [PATCH v9 05/37] mm: hugetlb: remove dead alloc_hugetlb_folio stub

[Dev Jain]

On 29/05/26 8:52 pm, Michael S. Tsirkin wrote:
> Remove the !CONFIG_HUGETLB_PAGE stub for alloc_hugetlb_folio().
> 
> The stub is dead code: all callers are in mm/hugetlb.c
> (CONFIG_HUGETLB_PAGE) or fs/hugetlbfs/inode.c (CONFIG_HUGETLBFS),
> and CONFIG_HUGETLB_PAGE is def_bool HUGETLBFS with nothing
> selecting it independently.
> 
> The stub is also broken: it returns NULL, but all callers check
> IS_ERR(folio), so a NULL return would not be caught and would
> crash on the subsequent folio dereference.
> 
> Remove it now since follow-up patches change the signature of
> alloc_hugetlb_folio and would otherwise need to update the
> broken stub too.
> 
> Signed-off-by: Michael S. Tsirkin <mst@xxxxxxxxxx>
> Reviewed-by: Gregory Price <gourry@xxxxxxxxxx>
> Assisted-by: Claude:claude-opus-4-6
> ---

Reviewed-by: Dev Jain <dev.jain@xxxxxxx>


>  include/linux/hugetlb.h | 7 -------
>  1 file changed, 7 deletions(-)
> 
> diff --git a/include/linux/hugetlb.h b/include/linux/hugetlb.h
> index 93418625d3c5..f016bc2e8936 100644
> --- a/include/linux/hugetlb.h
> +++ b/include/linux/hugetlb.h
> @@ -1129,13 +1129,6 @@ static inline void wait_for_freed_hugetlb_folios(void)
>  {
>  }
>  
> -static inline struct folio *alloc_hugetlb_folio(struct vm_area_struct *vma,
> -					   unsigned long addr,
> -					   bool cow_from_owner)
> -{
> -	return NULL;
> -}
> -
>  static inline struct folio *
>  alloc_hugetlb_folio_reserve(struct hstate *h, int preferred_nid,
>  			    nodemask_t *nmask, gfp_t gfp_mask)