diff options
Diffstat (limited to 'mm/rmap.c')
| -rw-r--r-- | mm/rmap.c | 66 |
1 files changed, 46 insertions, 20 deletions
diff --git a/mm/rmap.c b/mm/rmap.c index 0f00570d1b9e..78b7fb5f367c 100644 --- a/mm/rmap.c +++ b/mm/rmap.c @@ -457,6 +457,13 @@ static void cleanup_partial_anon_vmas(struct vm_area_struct *vma) list_del(&avc->same_vma); anon_vma_chain_free(avc); } + + /* + * The anon_vma assigned to this VMA is no longer valid, as we were not + * able to correctly clone AVC state. Avoid inconsistent anon_vma tree + * state by resetting. + */ + vma->anon_vma = NULL; } /** @@ -958,25 +965,25 @@ static bool folio_referenced_one(struct folio *folio, return false; } - if (lru_gen_enabled() && pvmw.pte) { - if (lru_gen_look_around(&pvmw)) - referenced++; - } else if (pvmw.pte) { - if (folio_test_large(folio)) { - unsigned long end_addr = pmd_addr_end(address, vma->vm_end); - unsigned int max_nr = (end_addr - address) >> PAGE_SHIFT; - pte_t pteval = ptep_get(pvmw.pte); + if (pvmw.pte && folio_test_large(folio)) { + const unsigned long end_addr = pmd_addr_end(address, vma->vm_end); + const unsigned int max_nr = (end_addr - address) >> PAGE_SHIFT; + pte_t pteval = ptep_get(pvmw.pte); - nr = folio_pte_batch(folio, pvmw.pte, - pteval, max_nr); - } + nr = folio_pte_batch(folio, pvmw.pte, pteval, max_nr); + } - ptes += nr; + /* + * When LRU is switching, we don’t know where the surrounding folios + * are. —they could be on active/inactive lists or on MGLRU. So the + * simplest approach is to disable this look-around optimization. + */ + if (lru_gen_enabled() && !lru_gen_switching() && pvmw.pte) { + if (lru_gen_look_around(&pvmw, nr)) + referenced++; + } else if (pvmw.pte) { if (clear_flush_young_ptes_notify(vma, address, pvmw.pte, nr)) referenced++; - /* Skip the batched PTEs */ - pvmw.pte += nr - 1; - pvmw.address += (nr - 1) * PAGE_SIZE; } else if (IS_ENABLED(CONFIG_TRANSPARENT_HUGEPAGE)) { if (pmdp_clear_flush_young_notify(vma, address, pvmw.pmd)) @@ -986,6 +993,7 @@ static bool folio_referenced_one(struct folio *folio, WARN_ON_ONCE(1); } + ptes += nr; pra->mapcount -= nr; /* * If we are sure that we batched the entire folio, @@ -995,6 +1003,10 @@ static bool folio_referenced_one(struct folio *folio, page_vma_mapped_walk_done(&pvmw); break; } + + /* Skip the batched PTEs */ + pvmw.pte += nr - 1; + pvmw.address += (nr - 1) * PAGE_SIZE; } if (referenced) @@ -1065,6 +1077,7 @@ int folio_referenced(struct folio *folio, int is_locked, .invalid_vma = invalid_folio_referenced_vma, }; + VM_WARN_ON_ONCE_FOLIO(folio_is_zone_device(folio), folio); *vm_flags = 0; if (!pra.mapcount) return 0; @@ -1955,7 +1968,14 @@ static inline unsigned int folio_unmap_pte_batch(struct folio *folio, if (userfaultfd_wp(vma)) return 1; - return folio_pte_batch(folio, pvmw->pte, pte, max_nr); + /* + * If unmap fails, we need to restore the ptes. To avoid accidentally + * upgrading write permissions for ptes that were not originally + * writable, and to avoid losing the soft-dirty bit, use the + * appropriate FPB flags. + */ + return folio_pte_batch_flags(folio, vma, pvmw->pte, &pte, max_nr, + FPB_RESPECT_WRITE | FPB_RESPECT_SOFT_DIRTY); } /* @@ -2046,7 +2066,7 @@ static bool try_to_unmap_one(struct folio *folio, struct vm_area_struct *vma, } if (!pvmw.pte) { - if (folio_test_anon(folio) && !folio_test_swapbacked(folio)) { + if (folio_test_lazyfree(folio)) { if (unmap_huge_pmd_locked(vma, pvmw.address, pvmw.pmd, folio)) goto walk_done; /* @@ -2443,11 +2463,17 @@ static bool try_to_migrate_one(struct folio *folio, struct vm_area_struct *vma, __maybe_unused pmd_t pmdval; if (flags & TTU_SPLIT_HUGE_PMD) { + /* + * split_huge_pmd_locked() might leave the + * folio mapped through PTEs. Retry the walk + * so we can detect this scenario and properly + * abort the walk. + */ split_huge_pmd_locked(vma, pvmw.address, pvmw.pmd, true); - ret = false; - page_vma_mapped_walk_done(&pvmw); - break; + flags &= ~TTU_SPLIT_HUGE_PMD; + page_vma_mapped_walk_restart(&pvmw); + continue; } #ifdef CONFIG_ARCH_ENABLE_THP_MIGRATION pmdval = pmdp_get(pvmw.pmd); |