diff --git a/mm/huge_memory.c b/mm/huge_memory.c index 653f2dc03403..b118bcd392cb 100644 --- a/mm/huge_memory.c +++ b/mm/huge_memory.c @@ -4983,7 +4983,7 @@ int set_pmd_migration_entry(struct page_vma_mapped_walk *pvmw, struct vm_area_struct *vma = pvmw->vma; struct mm_struct *mm = vma->vm_mm; unsigned long address = pvmw->address; - bool anon_exclusive; + bool anon_exclusive, present, writable, softdirty, uffd_wp; pmd_t pmdval; swp_entry_t entry; pmd_t pmdswp; @@ -4991,12 +4991,26 @@ int set_pmd_migration_entry(struct page_vma_mapped_walk *pvmw, if (!(pvmw->pmd && !pvmw->pte)) return 0; - flush_cache_range(vma, address, address + HPAGE_PMD_SIZE); - if (unlikely(!pmd_present(*pvmw->pmd))) - pmdval = pmdp_huge_get_and_clear(vma->vm_mm, address, pvmw->pmd); - else + present = pmd_present(*pvmw->pmd); + if (likely(present)) { + flush_cache_range(vma, address, address + HPAGE_PMD_SIZE); + pmdval = pmdp_invalidate(vma, address, pvmw->pmd); + writable = pmd_write(pmdval); + softdirty = pmd_soft_dirty(pmdval); + uffd_wp = pmd_uffd_wp(pmdval); + } else { + softleaf_t old_entry; + + pmdval = pmdp_huge_get_and_clear(vma->vm_mm, address, pvmw->pmd); + old_entry = softleaf_from_pmd(pmdval); + + writable = softleaf_is_device_private_write(old_entry); + softdirty = pmd_swp_soft_dirty(pmdval); + uffd_wp = pmd_swp_uffd_wp(pmdval); + } + /* See folio_try_share_anon_rmap_pmd(): invalidate PMD first. */ anon_exclusive = folio_test_anon(folio) && PageAnonExclusive(page); if (anon_exclusive && folio_try_share_anon_rmap_pmd(folio, page)) { @@ -5004,24 +5018,31 @@ int set_pmd_migration_entry(struct page_vma_mapped_walk *pvmw, return -EBUSY; } - if (pmd_dirty(pmdval)) - folio_mark_dirty(folio); - if (pmd_write(pmdval)) + /* Determine type of migration entry. */ + if (writable) entry = make_writable_migration_entry(page_to_pfn(page)); else if (anon_exclusive) entry = make_readable_exclusive_migration_entry(page_to_pfn(page)); else entry = make_readable_migration_entry(page_to_pfn(page)); - if (pmd_young(pmdval)) + + /* Set A/D bits as necessary. */ + if (present && pmd_young(pmdval)) entry = make_migration_entry_young(entry); - if (pmd_dirty(pmdval)) + if (present && pmd_dirty(pmdval)) { + folio_mark_dirty(folio); entry = make_migration_entry_dirty(entry); + } + + /* Set PMD. */ pmdswp = swp_entry_to_pmd(entry); - if (pmd_soft_dirty(pmdval)) + if (softdirty) pmdswp = pmd_swp_mksoft_dirty(pmdswp); - if (pmd_uffd_wp(pmdval)) + if (uffd_wp) pmdswp = pmd_swp_mkuffd_wp(pmdswp); set_pmd_at(mm, address, pvmw->pmd, pmdswp); + + /* Migration entry installed: cleanup rmap, folio. */ folio_remove_rmap_pmd(folio, page, vma); folio_put(folio); trace_set_migration_pmd(address, pmd_val(pmdswp));