Commit 84caf988 authored Jul 04, 2025 by David Hildenbrand Committed by Andrew Morton Jul 13, 2025

mm: stop storing migration_ops in page->mapping

...  instead, look them up statically based on the page type.  Maybe in
the future we want a registration interface?  At least for now, it can be
easily handled using the two page types that actually support page
migration.

The remaining usage of page->mapping is to flag such pages as actually
being movable (having movable_ops), which we will change next.

Link: https://lkml.kernel.org/r/20250704102524.326966-20-david@redhat.com


Signed-off-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Zi Yan <ziy@nvidia.com>
Reviewed-by: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Reviewed-by: Harry Yoo <harry.yoo@oracle.com>
Cc: Alistair Popple <apopple@nvidia.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Brendan Jackman <jackmanb@google.com>
Cc: Byungchul Park <byungchul@sk.com>
Cc: Chengming Zhou <chengming.zhou@linux.dev>
Cc: Christian Brauner <brauner@kernel.org>
Cc: Christophe Leroy <christophe.leroy@csgroup.eu>
Cc: Eugenio Pé rez <eperezma@redhat.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Gregory Price <gourry@gourry.net>
Cc: "Huang, Ying" <ying.huang@linux.alibaba.com>
Cc: Jan Kara <jack@suse.cz>
Cc: Jason Gunthorpe <jgg@ziepe.ca>
Cc: Jason Wang <jasowang@redhat.com>
Cc: Jerrin Shaji George <jerrin.shaji-george@broadcom.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: John Hubbard <jhubbard@nvidia.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Joshua Hahn <joshua.hahnjy@gmail.com>
Cc: Liam Howlett <liam.howlett@oracle.com>
Cc: Madhavan Srinivasan <maddy@linux.ibm.com>
Cc: Mathew Brost <matthew.brost@intel.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Miaohe Lin <linmiaohe@huawei.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: "Michael S. Tsirkin" <mst@redhat.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Naoya Horiguchi <nao.horiguchi@gmail.com>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: Oscar Salvador <osalvador@suse.de>
Cc: Peter Xu <peterx@redhat.com>
Cc: Qi Zheng <zhengqi.arch@bytedance.com>
Cc: Rakie Kim <rakie.kim@sk.com>
Cc: Rik van Riel <riel@surriel.com>
Cc: Sergey Senozhatsky <senozhatsky@chromium.org>
Cc: Shakeel Butt <shakeel.butt@linux.dev>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Xuan Zhuo <xuanzhuo@linux.alibaba.com>
Cc: xu xin <xu.xin16@zte.com.cn>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

parent 457d7b3a

include/linux/balloon_compaction.h

+1 −1

Original line number	Diff line number	Diff line
		@@ -92,7 +92,7 @@ static inline void balloon_page_insert(struct balloon_dev_info *balloon,
		struct page *page)
		{
		__SetPageOffline(page);
		__SetPageMovable(page, &balloon_mops);
		__SetPageMovable(page);
		set_page_private(page, (unsigned long)balloon);
		list_add(&page->lru, &balloon->pages);
		}

include/linux/migrate.h

+2 −12

Original line number	Diff line number	Diff line
		@@ -104,23 +104,13 @@ static inline int migrate_huge_page_move_mapping(struct address_space *mapping,
		#endif /* CONFIG_MIGRATION */

		#ifdef CONFIG_COMPACTION
		void __SetPageMovable(struct page page, const struct movable_operations ops);
		void __SetPageMovable(struct page *page);
		#else
		static inline void __SetPageMovable(struct page *page,
		const struct movable_operations *ops)
		static inline void __SetPageMovable(struct page *page)
		{
		}
		#endif

		static inline
		const struct movable_operations page_movable_ops(struct page page)
		{
		VM_WARN_ON_ONCE_PAGE(!page_has_movable_ops(page), page);

		return (const struct movable_operations *)
		((unsigned long)page->mapping - PAGE_MAPPING_MOVABLE);
		}

		#ifdef CONFIG_NUMA_BALANCING
		int migrate_misplaced_folio_prepare(struct folio *folio,
		struct vm_area_struct *vma, int node);

include/linux/zsmalloc.h

+2 −0

Original line number	Diff line number	Diff line
		@@ -46,4 +46,6 @@ void zs_obj_read_end(struct zs_pool *pool, unsigned long handle,
		void zs_obj_write(struct zs_pool *pool, unsigned long handle,
		void *handle_mem, size_t mem_len);

		extern const struct movable_operations zsmalloc_mops;

		#endif

mm/balloon_compaction.c

+0 −1

Original line number	Diff line number	Diff line
		@@ -253,6 +253,5 @@ const struct movable_operations balloon_mops = {
		.isolate_page = balloon_page_isolate,
		.putback_page = balloon_page_putback,
		};
		EXPORT_SYMBOL_GPL(balloon_mops);

		#endif /* CONFIG_BALLOON_COMPACTION */

mm/compaction.c

+2 −3

Original line number	Diff line number	Diff line
		@@ -114,11 +114,10 @@ static unsigned long release_free_list(struct list_head *freepages)
		}

		#ifdef CONFIG_COMPACTION
		void __SetPageMovable(struct page page, const struct movable_operations mops)
		void __SetPageMovable(struct page *page)
		{
		VM_BUG_ON_PAGE(!PageLocked(page), page);
		VM_BUG_ON_PAGE((unsigned long)mops & PAGE_MAPPING_MOVABLE, page);
		page->mapping = (void *)((unsigned long)mops \| PAGE_MAPPING_MOVABLE);
		page->mapping = (void *)(PAGE_MAPPING_MOVABLE);
		}
		EXPORT_SYMBOL(__SetPageMovable);