Re: [PATCH v4 16/25] huge_memory: Add vmf_insert_folio_pmd()

From: David Hildenbrand
Date: Fri Dec 20 2024 - 13:58:50 EST



+vm_fault_t vmf_insert_folio_pmd(struct vm_fault *vmf, struct folio *folio, bool write)
+{
+ struct vm_area_struct *vma = vmf->vma;
+ unsigned long addr = vmf->address & PMD_MASK;
+ pfn_t pfn = pfn_to_pfn_t(folio_pfn(folio));
+ struct mm_struct *mm = vma->vm_mm;
+ spinlock_t *ptl;
+ pgtable_t pgtable = NULL;
+ struct page *page;
+
+ if (addr < vma->vm_start || addr >= vma->vm_end)
+ return VM_FAULT_SIGBUS;
+
+ if (WARN_ON_ONCE(folio_order(folio) != PMD_ORDER))
+ return VM_FAULT_SIGBUS;
+
+ if (arch_needs_pgtable_deposit()) {
+ pgtable = pte_alloc_one(vma->vm_mm);
+ if (!pgtable)
+ return VM_FAULT_OOM;
+ }
+
+ track_pfn_insert(vma, &vma->vm_page_prot, pfn);
+
+ ptl = pmd_lock(mm, vmf->pmd);
+ if (pmd_none(*vmf->pmd)) {
+ page = pfn_t_to_page(pfn);
+ folio = page_folio(page);
+ folio_get(folio);
+ folio_add_file_rmap_pmd(folio, page, vma);
+ add_mm_counter(mm, mm_counter_file(folio), HPAGE_PMD_NR);
+ }

Same comments as for the PUD variant, apart from that nothing jumped at me.

--
Cheers,

David / dhildenb