Re: [PATCH v1 11/16] mm/memory: inline unmap_page_range() into __zap_vma_range()

[Lorenzo Stoakes (Oracle)]

On Fri, Feb 27, 2026 at 09:08:42PM +0100, David Hildenbrand (Arm) wrote:
> Let's inline it into the single caller to reduce the number of confusing
> unmap/zap helpers.
>
> Get rid of the unnecessary BUG_ON().
>
> Signed-off-by: David Hildenbrand (Arm) <david@xxxxxxxxxx>

Small nits below, but overall LGTM so:

Reviewed-by: Lorenzo Stoakes (Oracle) <ljs@xxxxxxxxxx>

> ---
>  mm/memory.c | 32 ++++++++++++--------------------
>  1 file changed, 12 insertions(+), 20 deletions(-)
>
> diff --git a/mm/memory.c b/mm/memory.c
> index 394b2e931974..1c0bcdfc73b7 100644
> --- a/mm/memory.c
> +++ b/mm/memory.c
> @@ -2056,25 +2056,6 @@ static inline unsigned long zap_p4d_range(struct mmu_gather *tlb,
>  	return addr;
>  }
>
> -static void unmap_page_range(struct mmu_gather *tlb, struct vm_area_struct *vma,
> -		unsigned long addr, unsigned long end,
> -		struct zap_details *details)
> -{
> -	pgd_t *pgd;
> -	unsigned long next;
> -
> -	BUG_ON(addr >= end);
> -	tlb_start_vma(tlb, vma);
> -	pgd = pgd_offset(vma->vm_mm, addr);
> -	do {
> -		next = pgd_addr_end(addr, end);
> -		if (pgd_none_or_clear_bad(pgd))
> -			continue;
> -		next = zap_p4d_range(tlb, vma, pgd, addr, next, details);
> -	} while (pgd++, addr = next, addr != end);
> -	tlb_end_vma(tlb, vma);
> -}
> -
>  static void __zap_vma_range(struct mmu_gather *tlb, struct vm_area_struct *vma,
>  		unsigned long start, unsigned long end,
>  		struct zap_details *details)
> @@ -2100,7 +2081,18 @@ static void __zap_vma_range(struct mmu_gather *tlb, struct vm_area_struct *vma,
>  			return;
>  		__unmap_hugepage_range(tlb, vma, start, end, NULL, zap_flags);
>  	} else {
> -		unmap_page_range(tlb, vma, start, end, details);
> +		unsigned long next, cur = start;

VERY nitty, but generally current is abbreviated to curr not cur.

It's not a big deal, but why not addr?

> +		pgd_t *pgd;
> +
> +		tlb_start_vma(tlb, vma);
> +		pgd = pgd_offset(vma->vm_mm, cur);
> +		do {
> +			next = pgd_addr_end(cur, end);
> +			if (pgd_none_or_clear_bad(pgd))
> +				continue;
> +			next = zap_p4d_range(tlb, vma, pgd, cur, next, details);
> +		} while (pgd++, cur = next, cur != end);
> +		tlb_end_vma(tlb, vma);
>  	}
>  }
>
> --
> 2.43.0
>