Re: [PATCH 1/7] mm/migrate: rename PAGE_ migration flags to FOLIO_
From: Dev Jain
Date: Tue Jun 09 2026 - 01:34:48 EST
On 28/04/26 9:20 pm, Shivank Garg wrote:
> These flags only track folio-specific state during migration and are
> not used for movable_ops pages. Rename the enum values and the
> old_page_state variable to match.
>
> No functional change.
>
> Suggested-by: David Hildenbrand <david@xxxxxxxxxx>
> Acked-by: David Hildenbrand (Arm) <david@xxxxxxxxxx>
> Reviewed-by: Zi Yan <ziy@xxxxxxxxxx>
> Reviewed-by: Baolin Wang <baolin.wang@xxxxxxxxxxxxxxxxx>
> Reviewed-by: Lance Yang <lance.yang@xxxxxxxxx>
> Signed-off-by: Shivank Garg <shivankg@xxxxxxx>
> ---
migrate_folio_undo_src() has a parameter "page_was_mapped", change that
too?
> mm/migrate.c | 48 +++++++++++++++++++++++-------------------------
> 1 file changed, 23 insertions(+), 25 deletions(-)
>
> diff --git a/mm/migrate.c b/mm/migrate.c
> index 8a64291ab5b4..0c6a0ab6ecce 100644
> --- a/mm/migrate.c
> +++ b/mm/migrate.c
> @@ -1135,26 +1135,24 @@ static int move_to_new_folio(struct folio *dst, struct folio *src,
> * This is safe because nobody is using it except us.
> */
> enum {
> - PAGE_WAS_MAPPED = BIT(0),
> - PAGE_WAS_MLOCKED = BIT(1),
> - PAGE_OLD_STATES = PAGE_WAS_MAPPED | PAGE_WAS_MLOCKED,
> + FOLIO_WAS_MAPPED = BIT(0),
> + FOLIO_WAS_MLOCKED = BIT(1),
> + FOLIO_OLD_STATES = FOLIO_WAS_MAPPED | FOLIO_WAS_MLOCKED,
> };
>
> static void __migrate_folio_record(struct folio *dst,
> - int old_page_state,
> - struct anon_vma *anon_vma)
> + int old_folio_state, struct anon_vma *anon_vma)
> {
> - dst->private = (void *)anon_vma + old_page_state;
> + dst->private = (void *)anon_vma + old_folio_state;
> }
>
> static void __migrate_folio_extract(struct folio *dst,
> - int *old_page_state,
> - struct anon_vma **anon_vmap)
> + int *old_folio_state, struct anon_vma **anon_vmap)
> {
> unsigned long private = (unsigned long)dst->private;
>
> - *anon_vmap = (struct anon_vma *)(private & ~PAGE_OLD_STATES);
> - *old_page_state = private & PAGE_OLD_STATES;
> + *anon_vmap = (struct anon_vma *)(private & ~FOLIO_OLD_STATES);
> + *old_folio_state = private & FOLIO_OLD_STATES;
> dst->private = NULL;
> }
>
> @@ -1209,7 +1207,7 @@ static int migrate_folio_unmap(new_folio_t get_new_folio,
> {
> struct folio *dst;
> int rc = -EAGAIN;
> - int old_page_state = 0;
> + int old_folio_state = 0;
> struct anon_vma *anon_vma = NULL;
> bool locked = false;
> bool dst_locked = false;
> @@ -1253,7 +1251,7 @@ static int migrate_folio_unmap(new_folio_t get_new_folio,
> }
> locked = true;
> if (folio_test_mlocked(src))
> - old_page_state |= PAGE_WAS_MLOCKED;
> + old_folio_state |= FOLIO_WAS_MLOCKED;
>
> if (folio_test_writeback(src)) {
> /*
> @@ -1302,7 +1300,7 @@ static int migrate_folio_unmap(new_folio_t get_new_folio,
> dst_locked = true;
>
> if (unlikely(page_has_movable_ops(&src->page))) {
> - __migrate_folio_record(dst, old_page_state, anon_vma);
> + __migrate_folio_record(dst, old_folio_state, anon_vma);
> return 0;
> }
>
> @@ -1328,11 +1326,11 @@ static int migrate_folio_unmap(new_folio_t get_new_folio,
> VM_BUG_ON_FOLIO(folio_test_anon(src) &&
> !folio_test_ksm(src) && !anon_vma, src);
> try_to_migrate(src, mode == MIGRATE_ASYNC ? TTU_BATCH_FLUSH : 0);
> - old_page_state |= PAGE_WAS_MAPPED;
> + old_folio_state |= FOLIO_WAS_MAPPED;
> }
>
> if (!folio_mapped(src)) {
> - __migrate_folio_record(dst, old_page_state, anon_vma);
> + __migrate_folio_record(dst, old_folio_state, anon_vma);
> return 0;
> }
>
> @@ -1344,7 +1342,7 @@ static int migrate_folio_unmap(new_folio_t get_new_folio,
> if (rc == -EAGAIN)
> ret = NULL;
>
> - migrate_folio_undo_src(src, old_page_state & PAGE_WAS_MAPPED,
> + migrate_folio_undo_src(src, old_folio_state & FOLIO_WAS_MAPPED,
> anon_vma, locked, ret);
> migrate_folio_undo_dst(dst, dst_locked, put_new_folio, private);
>
> @@ -1358,13 +1356,13 @@ static int migrate_folio_move(free_folio_t put_new_folio, unsigned long private,
> struct list_head *ret)
> {
> int rc;
> - int old_page_state = 0;
> + int old_folio_state = 0;
> struct anon_vma *anon_vma = NULL;
> bool src_deferred_split = false;
> bool src_partially_mapped = false;
> struct list_head *prev;
>
> - __migrate_folio_extract(dst, &old_page_state, &anon_vma);
> + __migrate_folio_extract(dst, &old_folio_state, &anon_vma);
> prev = dst->lru.prev;
> list_del(&dst->lru);
>
> @@ -1404,10 +1402,10 @@ static int migrate_folio_move(free_folio_t put_new_folio, unsigned long private,
> * isolated from the unevictable LRU: but this case is the easiest.
> */
> folio_add_lru(dst);
> - if (old_page_state & PAGE_WAS_MLOCKED)
> + if (old_folio_state & FOLIO_WAS_MLOCKED)
> lru_add_drain();
>
> - if (old_page_state & PAGE_WAS_MAPPED)
> + if (old_folio_state & FOLIO_WAS_MAPPED)
> remove_migration_ptes(src, dst, 0);
>
> out_unlock_both:
> @@ -1439,11 +1437,11 @@ static int migrate_folio_move(free_folio_t put_new_folio, unsigned long private,
> */
> if (rc == -EAGAIN) {
> list_add(&dst->lru, prev);
> - __migrate_folio_record(dst, old_page_state, anon_vma);
> + __migrate_folio_record(dst, old_folio_state, anon_vma);
> return rc;
> }
>
> - migrate_folio_undo_src(src, old_page_state & PAGE_WAS_MAPPED,
> + migrate_folio_undo_src(src, old_folio_state & FOLIO_WAS_MAPPED,
> anon_vma, true, ret);
> migrate_folio_undo_dst(dst, true, put_new_folio, private);
>
> @@ -1777,11 +1775,11 @@ static void migrate_folios_undo(struct list_head *src_folios,
> dst = list_first_entry(dst_folios, struct folio, lru);
> dst2 = list_next_entry(dst, lru);
> list_for_each_entry_safe(folio, folio2, src_folios, lru) {
> - int old_page_state = 0;
> + int old_folio_state = 0;
> struct anon_vma *anon_vma = NULL;
>
> - __migrate_folio_extract(dst, &old_page_state, &anon_vma);
> - migrate_folio_undo_src(folio, old_page_state & PAGE_WAS_MAPPED,
> + __migrate_folio_extract(dst, &old_folio_state, &anon_vma);
> + migrate_folio_undo_src(folio, old_folio_state & FOLIO_WAS_MAPPED,
> anon_vma, true, ret_folios);
> list_del(&dst->lru);
> migrate_folio_undo_dst(dst, true, put_new_folio, private);