Re: [PATCH v1 4/9] mm/memory: factor out zapping folio pte into zap_present_folio_pte()

Ryan Roberts
2024-01-30T08:47:38Z

On 29/01/2024 14:32, David Hildenbrand wrote:
> Let's prepare for further changes by factoring it out into a separate
> function.
>
> Signed-off-by: David Hildenbrand <david@redhat.com>

Reviewed-by: Ryan Roberts <ryan.roberts@arm.com>

> ---
> mm/memory.c | 53 ++++++++++++++++++++++++++++++++---------------------
> 1 file changed, 32 insertions(+), 21 deletions(-)
>
> diff --git a/mm/memory.c b/mm/memory.c
> index 20bc13ab8db2..a2190d7cfa74 100644
> --- a/mm/memory.c
> +++ b/mm/memory.c
> @@ -1528,30 +1528,14 @@ zap_install_uffd_wp_if_needed(struct vm_area_struct *vma,
> pte_install_uffd_wp_if_needed(vma, addr, pte, pteval);
> }
>
> -static inline void zap_present_pte(struct mmu_gather *tlb,
> - struct vm_area_struct *vma, pte_t *pte, pte_t ptent,
> - unsigned long addr, struct zap_details *details,
> - int *rss, bool *force_flush, bool *force_break)
> +static inline void zap_present_folio_pte(struct mmu_gather *tlb,
> + struct vm_area_struct *vma, struct folio *folio,
> + struct page *page, pte_t *pte, pte_t ptent, unsigned long addr,
> + struct zap_details *details, int *rss, bool *force_flush,
> + bool *force_break)
> {
> struct mm_struct *mm = tlb->mm;
> bool delay_rmap = false;
> - struct folio *folio;
> - struct page *page;
> -
> - page = vm_normal_page(vma, addr, ptent);
> - if (!page) {
> - /* We don't need up-to-date accessed/dirty bits. */
> - ptep_get_and_clear_full(mm, addr, pte, tlb->fullmm);
> - arch_check_zapped_pte(vma, ptent);
> - tlb_remove_tlb_entry(tlb, pte, addr);
> - VM_WARN_ON_ONCE(userfaultfd_wp(vma));
> - ksm_might_unmap_zero_page(mm, ptent);
> - return;
> - }
> -
> - folio = page_folio(page);
> - if (unlikely(!should_zap_folio(details, folio)))
> - return;
>
> if (!folio_test_anon(folio)) {
> ptent = ptep_get_and_clear_full(mm, addr, pte, tlb->fullmm);
> @@ -1586,6 +1570,33 @@ static inline void zap_present_pte(struct mmu_gather *tlb,
> }
> }
>
> +static inline void zap_present_pte(struct mmu_gather *tlb,
> + struct vm_area_struct *vma, pte_t *pte, pte_t ptent,
> + unsigned long addr, struct zap_details *details,
> + int *rss, bool *force_flush, bool *force_break)
> +{
> + struct mm_struct *mm = tlb->mm;
> + struct folio *folio;
> + struct page *page;
> +
> + page = vm_normal_page(vma, addr, ptent);
> + if (!page) {
> + /* We don't need up-to-date accessed/dirty bits. */
> + ptep_get_and_clear_full(mm, addr, pte, tlb->fullmm);
> + arch_check_zapped_pte(vma, ptent);
> + tlb_remove_tlb_entry(tlb, pte, addr);
> + VM_WARN_ON_ONCE(userfaultfd_wp(vma));
> + ksm_might_unmap_zero_page(mm, ptent);
> + return;
> + }
> +
> + folio = page_folio(page);
> + if (unlikely(!should_zap_folio(details, folio)))
> + return;
> + zap_present_folio_pte(tlb, vma, folio, page, pte, ptent, addr, details,
> + rss, force_flush, force_break);
> +}
> +
> static unsigned long zap_pte_range(struct mmu_gather *tlb,
> struct vm_area_struct *vma, pmd_t *pmd,
> unsigned long addr, unsigned long end,