Re: [PATCH 1/7] mm/migrate: rename PAGE_ migration flags to FOLIO_

[Dev Jain <dev.jain@arm.com>]

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@kernel.org>
> Acked-by: David Hildenbrand (Arm) <david@kernel.org>
> Reviewed-by: Zi Yan <ziy@nvidia.com>
> Reviewed-by: Baolin Wang <baolin.wang@linux.alibaba.com>
> Reviewed-by: Lance Yang <lance.yang@linux.dev>
> Signed-off-by: Shivank Garg <shivankg@amd.com>
> ---

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);