diff options
Diffstat (limited to 'mm/migrate.c')
| -rw-r--r-- | mm/migrate.c | 45 |
1 files changed, 15 insertions, 30 deletions
diff --git a/mm/migrate.c b/mm/migrate.c index 25e7438af968..2bcfc41b7e4c 100644 --- a/mm/migrate.c +++ b/mm/migrate.c @@ -198,19 +198,16 @@ bool isolate_folio_to_list(struct folio *folio, struct list_head *list) } static bool try_to_map_unused_to_zeropage(struct page_vma_mapped_walk *pvmw, - struct folio *folio, - unsigned long idx) + struct folio *folio, pte_t old_pte, unsigned long idx) { struct page *page = folio_page(folio, idx); - bool contains_data; pte_t newpte; - void *addr; if (PageCompound(page)) return false; VM_BUG_ON_PAGE(!PageAnon(page), page); VM_BUG_ON_PAGE(!PageLocked(page), page); - VM_BUG_ON_PAGE(pte_present(*pvmw->pte), page); + VM_BUG_ON_PAGE(pte_present(old_pte), page); if (folio_test_mlocked(folio) || (pvmw->vma->vm_flags & VM_LOCKED) || mm_forbids_zeropage(pvmw->vma->vm_mm)) @@ -221,15 +218,17 @@ static bool try_to_map_unused_to_zeropage(struct page_vma_mapped_walk *pvmw, * this subpage has been non present. If the subpage is only zero-filled * then map it to the shared zeropage. */ - addr = kmap_local_page(page); - contains_data = memchr_inv(addr, 0, PAGE_SIZE); - kunmap_local(addr); - - if (contains_data) + if (!pages_identical(page, ZERO_PAGE(0))) return false; newpte = pte_mkspecial(pfn_pte(my_zero_pfn(pvmw->address), pvmw->vma->vm_page_prot)); + + if (pte_swp_soft_dirty(old_pte)) + newpte = pte_mksoft_dirty(newpte); + if (pte_swp_uffd_wp(old_pte)) + newpte = pte_mkuffd_wp(newpte); + set_pte_at(pvmw->vma->vm_mm, pvmw->address, pvmw->pte, newpte); dec_mm_counter(pvmw->vma->vm_mm, mm_counter(folio)); @@ -272,13 +271,13 @@ static bool remove_migration_pte(struct folio *folio, continue; } #endif + old_pte = ptep_get(pvmw.pte); if (rmap_walk_arg->map_unused_to_zeropage && - try_to_map_unused_to_zeropage(&pvmw, folio, idx)) + try_to_map_unused_to_zeropage(&pvmw, folio, old_pte, idx)) continue; folio_get(folio); pte = mk_pte(new, READ_ONCE(vma->vm_page_prot)); - old_pte = ptep_get(pvmw.pte); entry = pte_to_swp_entry(old_pte); if (!is_migration_entry_young(entry)) @@ -453,20 +452,6 @@ unlock: } #endif -static int folio_expected_refs(struct address_space *mapping, - struct folio *folio) -{ - int refs = 1; - if (!mapping) - return refs; - - refs += folio_nr_pages(folio); - if (folio_test_private(folio)) - refs++; - - return refs; -} - /* * Replace the folio in the mapping. * @@ -609,7 +594,7 @@ static int __folio_migrate_mapping(struct address_space *mapping, int folio_migrate_mapping(struct address_space *mapping, struct folio *newfolio, struct folio *folio, int extra_count) { - int expected_count = folio_expected_refs(mapping, folio) + extra_count; + int expected_count = folio_expected_ref_count(folio) + extra_count + 1; if (folio_ref_count(folio) != expected_count) return -EAGAIN; @@ -626,7 +611,7 @@ int migrate_huge_page_move_mapping(struct address_space *mapping, struct folio *dst, struct folio *src) { XA_STATE(xas, &mapping->i_pages, folio_index(src)); - int rc, expected_count = folio_expected_refs(mapping, src); + int rc, expected_count = folio_expected_ref_count(src) + 1; if (folio_ref_count(src) != expected_count) return -EAGAIN; @@ -756,7 +741,7 @@ static int __migrate_folio(struct address_space *mapping, struct folio *dst, struct folio *src, void *src_private, enum migrate_mode mode) { - int rc, expected_count = folio_expected_refs(mapping, src); + int rc, expected_count = folio_expected_ref_count(src) + 1; /* Check whether src does not have extra refs before we do more work */ if (folio_ref_count(src) != expected_count) @@ -844,7 +829,7 @@ static int __buffer_migrate_folio(struct address_space *mapping, return migrate_folio(mapping, dst, src, mode); /* Check whether page does not have extra refs before we do more work */ - expected_count = folio_expected_refs(mapping, src); + expected_count = folio_expected_ref_count(src) + 1; if (folio_ref_count(src) != expected_count) return -EAGAIN; |