Re: [PATCH v1 08/29] mm/migrate: rename putback_movable_folio() to putback_movable_ops_page()

Lorenzo Stoakes
2025-06-30T16:30:47Z

On Mon, Jun 30, 2025 at 02:59:49PM +0200, David Hildenbrand wrote:
> ... and factor the complete handling of movable_ops pages out.
> Convert it similar to isolate_movable_ops_page().
>
> While at it, convert the VM_BUG_ON_FOLIO() into a VM_WARN_ON_PAGE().

<3

>
> Signed-off-by: David Hildenbrand <david@redhat.com>

LGTM, so:

Reviewed-by: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>

> ---
> mm/migrate.c | 37 ++++++++++++++++++++++++-------------
> 1 file changed, 24 insertions(+), 13 deletions(-)
>
> diff --git a/mm/migrate.c b/mm/migrate.c
> index d4b4a7eefb6bd..d97f7cd137e63 100644
> --- a/mm/migrate.c
> +++ b/mm/migrate.c
> @@ -133,12 +133,30 @@ bool isolate_movable_ops_page(struct page *page, isolate_mode_t mode)
> return false;
> }
>
> -static void putback_movable_folio(struct folio *folio)
> +/**
> + * putback_movable_ops_page - putback an isolated movable_ops page
> + * @page: The isolated page.
> + *
> + * Putback an isolated movable_ops page.
> + *
> + * After the page was putback, it might get freed instantly.
> + */
> +static void putback_movable_ops_page(struct page *page)
> {
> - const struct movable_operations *mops = folio_movable_ops(folio);
> -
> - mops->putback_page(&folio->page);
> - folio_clear_isolated(folio);
> + /*
> + * TODO: these pages will not be folios in the future. All
> + * folio dependencies will have to be removed.
> + */
> + struct folio *folio = page_folio(page);
> +
> + VM_WARN_ON_ONCE_PAGE(!PageIsolated(page), page);
> + folio_lock(folio);
> + /* If the page was released by it's owner, there is nothing to do. */
> + if (PageMovable(page))
> + page_movable_ops(page)->putback_page(page);
> + ClearPageIsolated(page);
> + folio_unlock(folio);
> + folio_put(folio);
> }
>
> /*
> @@ -166,14 +184,7 @@ void putback_movable_pages(struct list_head *l)
> * have PAGE_MAPPING_MOVABLE.
> */
> if (unlikely(__folio_test_movable(folio))) {
> - VM_BUG_ON_FOLIO(!folio_test_isolated(folio), folio);
> - folio_lock(folio);
> - if (folio_test_movable(folio))
> - putback_movable_folio(folio);
> - else
> - folio_clear_isolated(folio);
> - folio_unlock(folio);
> - folio_put(folio);
> + putback_movable_ops_page(&folio->page);
> } else {
> node_stat_mod_folio(folio, NR_ISOLATED_ANON +
> folio_is_file_lru(folio), -folio_nr_pages(folio));
> --
> 2.49.0
>