Re: [PATCH v3 4/4] mm/hugetlb: Convert use of struct page to folio in __unmap_hugepage_range()

David Hildenbrand
2025-04-28T20:53:47Z

On 28.04.25 19:11, nifan.cxl@gmail.com wrote:
> From: Fan Ni <fan.ni@samsung.com>
>
> In __unmap_hugepage_range(), the "page" pointer always points to the
> first page of a huge page, which guarantees there is a folio associating
> with it. Convert the "page" pointer to use folio.
>
> Signed-off-by: Fan Ni <fan.ni@samsung.com>
> ---
> mm/hugetlb.c | 24 +++++++++++++-----------
> 1 file changed, 13 insertions(+), 11 deletions(-)
>
> diff --git a/mm/hugetlb.c b/mm/hugetlb.c
> index 6696206d556e..293c2afa724b 100644
> --- a/mm/hugetlb.c
> +++ b/mm/hugetlb.c
> @@ -5815,12 +5815,12 @@ void __unmap_hugepage_range(struct mmu_gather *tlb, struct vm_area_struct *vma,
> pte_t *ptep;
> pte_t pte;
> spinlock_t *ptl;
> - struct page *page;
> struct hstate *h = hstate_vma(vma);
> unsigned long sz = huge_page_size(h);
> bool adjust_reservation = false;
> unsigned long last_addr_mask;
> bool force_flush = false;
> + const bool folio_provided = !!folio;

I would but that all the way to the top.

> }
> @@ -5943,16 +5944,17 @@ void __unmap_hugepage_range(struct mmu_gather *tlb, struct vm_area_struct *vma,
> * count will not be incremented by free_huge_folio.
> * Act as if we consumed the reservation.
> */
> - folio_clear_hugetlb_restore_reserve(page_folio(page));
> + folio_clear_hugetlb_restore_reserve(folio);
> else if (rc)
> vma_add_reservation(h, vma, address);
> }
>
> - tlb_remove_page_size(tlb, page, huge_page_size(h));
> + tlb_remove_page_size(tlb, folio_page(folio, 0),
> + folio_size(folio));
> /*
> * Bail out after unmapping reference page if supplied
> */

I wonder if we want to adjust that comment while at it.

/* If we were instructed to unmap a specific folio, we're done. */

Acked-by: David Hildenbrand <david@redhat.com>

--
Cheers,

David / dhildenb