Re: [PATCH 16/30] mm/vma: use vma_start_pgoff(), linear_page_index() in mm code

[Pedro Falcato]

small nit: perhaps the subject should simply have mm: as it hits mm in general

On Mon, Jun 29, 2026 at 01:23:27PM +0100, Lorenzo Stoakes wrote:
> There are many instances in which linear_page_index() (as well as
> linear_page_delta()) is open-coded, which is confusing and inconsistent.
> 
> Additionally, vma->vm_pgoff doesn't necessarily make it clear that this is
> the page offset of the start of the VMA range.
> 
> Doing so also aids greppability.
> 
> So use vma_start_pgoff() in favour of directly accessing vma->vm_pgoff, and
> linear_page_index() where we can.
> 
> This also lays the ground for future changes which will add an anonymous
> page offset in order to be able to index MAP_PRIVATE-file backed anon
> folios in terms of their virtual page offset.
> 
> No functional change intended.
> 
> Signed-off-by: Lorenzo Stoakes <ljs@xxxxxxxxxx>
> ---
>  include/linux/huge_mm.h    |  1 +
>  include/linux/hugetlb.h    |  3 +--
>  include/linux/pagemap.h    |  2 +-
>  mm/damon/vaddr.c           |  5 +++--
>  mm/debug.c                 |  2 +-
>  mm/filemap.c               |  7 ++++---
>  mm/huge_memory.c           |  2 +-
>  mm/hugetlb.c               | 11 ++++-------
>  mm/internal.h              | 24 ++++++++++++++----------
>  mm/khugepaged.c            |  3 ++-
>  mm/madvise.c               |  6 +++---
>  mm/mapping_dirty_helpers.c |  2 +-
>  mm/memory.c                | 25 +++++++++++++------------
>  mm/mempolicy.c             | 13 +++++++------
>  mm/mremap.c                | 12 ++++--------
>  mm/msync.c                 |  4 ++--
>  mm/nommu.c                 |  7 ++++---
>  mm/pagewalk.c              |  2 +-
>  mm/shmem.c                 |  9 +++++----
>  mm/userfaultfd.c           |  4 ++--
>  mm/util.c                  |  4 ++--
>  mm/vma.c                   | 15 +++++++--------
>  mm/vma_exec.c              |  4 ++--
>  mm/vma_init.c              |  2 +-
>  24 files changed, 86 insertions(+), 83 deletions(-)
> 
> diff --git a/include/linux/huge_mm.h b/include/linux/huge_mm.h
> index ad20f7f8c179..653b81d08fe7 100644
> --- a/include/linux/huge_mm.h
> +++ b/include/linux/huge_mm.h
> @@ -230,6 +230,7 @@ static inline bool thp_vma_suitable_order(struct vm_area_struct *vma,
>  
>  	/* Don't have to check pgoff for anonymous vma */
>  	if (!vma_is_anonymous(vma)) {
> +		/* vma_start_pgoff() in mm.h so not available. */

Yay for gigaheaders...

>  		if (!IS_ALIGNED((vma->vm_start >> PAGE_SHIFT) - vma->vm_pgoff,
>  				hpage_size >> PAGE_SHIFT))
>  			return false;
> diff --git a/include/linux/hugetlb.h b/include/linux/hugetlb.h
> index 2abaf99321e9..8390f50604d6 100644
> --- a/include/linux/hugetlb.h
> +++ b/include/linux/hugetlb.h
> @@ -792,8 +792,7 @@ static inline pgoff_t hugetlb_linear_page_index(struct vm_area_struct *vma,
>  {
>  	struct hstate *h = hstate_vma(vma);
>  
> -	return ((address - vma->vm_start) >> huge_page_shift(h)) +
> -		(vma->vm_pgoff >> huge_page_order(h));
> +	return linear_page_index(vma, address) >> huge_page_order(h);
>  }
>  

Anyway, nothing jumped out at me.

Reviewed-by: Pedro Falcato <pfalcato@xxxxxxx>


-- 
Pedro