Re: [PATCH 3/5] mm: Rename __thp_get_unmapped_area to mm_get_unmapped_area_aligned

[Zi Yan]

On 13 Jun 2025, at 9:41, Peter Xu wrote:

> This function is pretty handy for any type of VMA to provide a size-aligned
> VMA address when mmap().  Rename the function and export it.
>
> About the rename:
>
>   - Dropping "THP" because it doesn't really have much to do with THP
>     internally.
>
>   - The suffix "_aligned" imply it is a helper to generate aligned virtual
>     address based on what is specified (which can be not PMD_SIZE).
>
> Cc: Zi Yan <ziy@xxxxxxxxxx>
> Cc: Baolin Wang <baolin.wang@xxxxxxxxxxxxxxxxx>
> Cc: Lorenzo Stoakes <lorenzo.stoakes@xxxxxxxxxx>
> Cc: "Liam R. Howlett" <Liam.Howlett@xxxxxxxxxx>
> Cc: Ryan Roberts <ryan.roberts@xxxxxxx>
> Cc: Dev Jain <dev.jain@xxxxxxx>
> Cc: Barry Song <baohua@xxxxxxxxxx>
> Signed-off-by: Peter Xu <peterx@xxxxxxxxxx>
> ---
>  include/linux/huge_mm.h | 14 +++++++++++++-
>  mm/huge_memory.c        |  6 ++++--
>  2 files changed, 17 insertions(+), 3 deletions(-)
>
> diff --git a/include/linux/huge_mm.h b/include/linux/huge_mm.h
> index 2f190c90192d..706488d92bb6 100644
> --- a/include/linux/huge_mm.h
> +++ b/include/linux/huge_mm.h
> @@ -339,7 +339,10 @@ unsigned long thp_get_unmapped_area(struct file *filp, unsigned long addr,
>  unsigned long thp_get_unmapped_area_vmflags(struct file *filp, unsigned long addr,
>  		unsigned long len, unsigned long pgoff, unsigned long flags,
>  		vm_flags_t vm_flags);
> -
> +unsigned long mm_get_unmapped_area_aligned(struct file *filp,
> +		unsigned long addr, unsigned long len,
> +		loff_t off, unsigned long flags, unsigned long size,
> +		vm_flags_t vm_flags);
>  bool can_split_folio(struct folio *folio, int caller_pins, int *pextra_pins);
>  int split_huge_page_to_list_to_order(struct page *page, struct list_head *list,
>  		unsigned int new_order);
> @@ -543,6 +546,15 @@ thp_get_unmapped_area_vmflags(struct file *filp, unsigned long addr,
>  	return 0;
>  }
>
> +static inline unsigned long
> +mm_get_unmapped_area_aligned(struct file *filp,
> +			     unsigned long addr, unsigned long len,
> +			     loff_t off, unsigned long flags, unsigned long size,
> +			     vm_flags_t vm_flags)
> +{
> +	return 0;
> +}
> +
>  static inline bool
>  can_split_folio(struct folio *folio, int caller_pins, int *pextra_pins)
>  {
> diff --git a/mm/huge_memory.c b/mm/huge_memory.c
> index 4734de1dc0ae..52f13a70562f 100644
> --- a/mm/huge_memory.c
> +++ b/mm/huge_memory.c
> @@ -1088,7 +1088,7 @@ static inline bool is_transparent_hugepage(const struct folio *folio)
>  		folio_test_large_rmappable(folio);
>  }
>
> -static unsigned long __thp_get_unmapped_area(struct file *filp,
> +unsigned long mm_get_unmapped_area_aligned(struct file *filp,
>  		unsigned long addr, unsigned long len,
>  		loff_t off, unsigned long flags, unsigned long size,

Since you added aligned suffix, renaming size to alignment might
help improve readability.

Otherwise, Reviewed-by: Zi Yan <ziy@xxxxxxxxxx>


Best Regards,
Yan, Zi