Re: [PATCH 01/30] mm: move vma_start_pgoff() into mm.h and clean up

[Pedro Falcato]

On Mon, Jun 29, 2026 at 01:23:12PM +0100, Lorenzo Stoakes wrote:
> vma_last_pgoff() already lives there, so it's a bit odd to keep
> vma_start_pgoff() in mm/interval_tree.c. Move them together.

Hmm, a part of me wonders if this is the part where we should start cleaning
up mm.h into vma.h or something. Probably not, it would be extra churn right
now.

> 
> These each return unsigned long, which pgoff_t is typedef'd to. Make this
> consistent and have these functions return pgoff_t instead.
> 
> Additionally, express vma_last_pgoff() in terms of vma_start_pgoff(), since
> we wrap the vma->vm_pgoff access, we may as well use it here.
> 
> Also while we're here, const-ify the VMA and cleanup a bit.
> 
> No functional change intended.
> 
> Signed-off-by: Lorenzo Stoakes <ljs@xxxxxxxxxx>

Reviewed-by: Pedro Falcato <pfalcato@xxxxxxx>

> ---
>  include/linux/mm.h | 9 +++++++--
>  mm/interval_tree.c | 5 -----
>  2 files changed, 7 insertions(+), 7 deletions(-)
> 
> diff --git a/include/linux/mm.h b/include/linux/mm.h
> index 485df9c2dbdd..059144435729 100644
> --- a/include/linux/mm.h
> +++ b/include/linux/mm.h
> @@ -4278,9 +4278,14 @@ static inline unsigned long vma_pages(const struct vm_area_struct *vma)
>  	return (vma->vm_end - vma->vm_start) >> PAGE_SHIFT;
>  }
>  
> -static inline unsigned long vma_last_pgoff(struct vm_area_struct *vma)
> +static inline pgoff_t vma_start_pgoff(const struct vm_area_struct *vma)
>  {
> -	return vma->vm_pgoff + vma_pages(vma) - 1;
> +	return vma->vm_pgoff;
> +}
> +
> +static inline pgoff_t vma_last_pgoff(const struct vm_area_struct *vma)
> +{
> +	return vma_start_pgoff(vma) + vma_pages(vma) - 1;
>  }
>  
>  static inline unsigned long vma_desc_size(const struct vm_area_desc *desc)
> diff --git a/mm/interval_tree.c b/mm/interval_tree.c
> index 32bcfbfcf15f..344d1f5946c7 100644
> --- a/mm/interval_tree.c
> +++ b/mm/interval_tree.c
> @@ -10,11 +10,6 @@
>  #include <linux/rmap.h>
>  #include <linux/interval_tree_generic.h>
>  
> -static inline unsigned long vma_start_pgoff(struct vm_area_struct *v)
> -{
> -	return v->vm_pgoff;
> -}
> -
>  INTERVAL_TREE_DEFINE(struct vm_area_struct, shared.rb,
>  		     unsigned long, shared.rb_subtree_last,
>  		     vma_start_pgoff, vma_last_pgoff, /* empty */, vma_interval_tree)
> -- 
> 2.54.0
> 

-- 
Pedro