From 3d388584d59985e95f5bfb9dbd9776fa1bb1ec8a Mon Sep 17 00:00:00 2001 From: David Hildenbrand Date: Fri, 4 Jul 2025 12:25:14 +0200 Subject: mm: convert "movable" flag in page->mapping to a page flag MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Instead, let's use a page flag. As the page flag can result in false-positives, glue it to the page types for which we support/implement movable_ops page migration. We are reusing PG_uptodate, that is for example used to track file system state and does not apply to movable_ops pages. So warning in case it is set in page_has_movable_ops() on other page types could result in false-positive warnings. Likely we could set the bit using a non-atomic update: in contrast to page->mapping, we could have others trying to update the flags concurrently when trying to lock the folio. In isolate_movable_ops_page(), we already take care of that by checking if the page has movable_ops before locking it. Let's start with the atomic variant, we could later switch to the non-atomic variant once we are sure other cases are similarly fine. Once we perform the switch, we'll have to introduce __SETPAGEFLAG_NOOP(). [david@redhat.com: add missing `:' in kerneldoc] Link: https://lkml.kernel.org/r/d96e2916-2c43-462c-b6a1-2375ef397d8b@redhat.com Link: https://lkml.kernel.org/r/20250704102524.326966-21-david@redhat.com Signed-off-by: David Hildenbrand Reviewed-by: Zi Yan Reviewed-by: Lorenzo Stoakes Cc: Alistair Popple Cc: Al Viro Cc: Arnd Bergmann Cc: Brendan Jackman Cc: Byungchul Park Cc: Chengming Zhou Cc: Christian Brauner Cc: Christophe Leroy Cc: Eugenio Pé rez Cc: Greg Kroah-Hartman Cc: Gregory Price Cc: Harry Yoo Cc: "Huang, Ying" Cc: Jan Kara Cc: Jason Gunthorpe Cc: Jason Wang Cc: Jerrin Shaji George Cc: Johannes Weiner Cc: John Hubbard Cc: Jonathan Corbet Cc: Joshua Hahn Cc: Liam Howlett Cc: Madhavan Srinivasan Cc: Mathew Brost Cc: Matthew Wilcox (Oracle) Cc: Miaohe Lin Cc: Michael Ellerman Cc: "Michael S. Tsirkin" Cc: Michal Hocko Cc: Mike Rapoport Cc: Minchan Kim Cc: Naoya Horiguchi Cc: Nicholas Piggin Cc: Oscar Salvador Cc: Peter Xu Cc: Qi Zheng Cc: Rakie Kim Cc: Rik van Riel Cc: Sergey Senozhatsky Cc: Shakeel Butt Cc: Suren Baghdasaryan Cc: Vlastimil Babka Cc: Xuan Zhuo Cc: xu xin Signed-off-by: Andrew Morton --- include/linux/migrate.h | 8 -------- 1 file changed, 8 deletions(-) (limited to 'include/linux/migrate.h') diff --git a/include/linux/migrate.h b/include/linux/migrate.h index 6aece3f3c8be..acadd41e0b5c 100644 --- a/include/linux/migrate.h +++ b/include/linux/migrate.h @@ -103,14 +103,6 @@ static inline int migrate_huge_page_move_mapping(struct address_space *mapping, #endif /* CONFIG_MIGRATION */ -#ifdef CONFIG_COMPACTION -void __SetPageMovable(struct page *page); -#else -static inline void __SetPageMovable(struct page *page) -{ -} -#endif - #ifdef CONFIG_NUMA_BALANCING int migrate_misplaced_folio_prepare(struct folio *folio, struct vm_area_struct *vma, int node); -- cgit v1.2.3