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

Lorenzo Stoakes (Oracle)
2026-03-06T21:17:36Z

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@kernel.org>

Small nits below, but overall LGTM so:

Reviewed-by: Lorenzo Stoakes (Oracle) <ljs@kernel.org>

> ---
> 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
>