Commit 22d103ae authored by David Hildenbrand's avatar David Hildenbrand Committed by Andrew Morton
Browse files

mm/migration: remove PageMovable() 

Previously, if __ClearPageMovable() were invoked on a page, this would
cause __PageMovable() to return false, but due to the continued existence
of page movable ops, PageMovable() would have returned true.

With __ClearPageMovable() gone, the two are exactly equivalent.

So we can replace PageMovable() checks by __PageMovable().  In fact,
__PageMovable() cannot change until a page is freed, so we can turn some
PageMovable() into sanity checks for __PageMovable().

Link: https://lkml.kernel.org/r/20250704102524.326966-16-david@redhat.com


Signed-off-by: default avatarDavid Hildenbrand <david@redhat.com>
Reviewed-by: default avatarZi Yan <ziy@nvidia.com>
Reviewed-by: default avatarLorenzo Stoakes <lorenzo.stoakes@oracle.com>
Reviewed-by: default avatarHarry 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: default avatarAndrew Morton <akpm@linux-foundation.org>
parent 34727dee

include/linux/migrate.h

+0 −2
Original line number Diff line number Diff line
@@ -104,10 +104,8 @@ static inline int migrate_huge_page_move_mapping(struct address_space *mapping, 
#endif /* CONFIG_MIGRATION */



#ifdef CONFIG_COMPACTION

bool PageMovable(struct page *page);

void __SetPageMovable(struct page *page, const struct movable_operations *ops);

#else

static inline bool PageMovable(struct page *page) { return false; }

static inline void __SetPageMovable(struct page *page,

		const struct movable_operations *ops)

{

mm/compaction.c

+0 −15
Original line number Diff line number Diff line
@@ -114,21 +114,6 @@ static unsigned long release_free_list(struct list_head *freepages) 
}



#ifdef CONFIG_COMPACTION

bool PageMovable(struct page *page)

{

	const struct movable_operations *mops;



	VM_BUG_ON_PAGE(!PageLocked(page), page);

	if (!__PageMovable(page))

		return false;



	mops = page_movable_ops(page);

	if (mops)

		return true;



	return false;

}



void __SetPageMovable(struct page *page, const struct movable_operations *mops)

{

	VM_BUG_ON_PAGE(!PageLocked(page), page);

mm/migrate.c

+10 −8
Original line number Diff line number Diff line
@@ -87,9 +87,12 @@ bool isolate_movable_ops_page(struct page *page, isolate_mode_t mode) 
		goto out;



	/*

	 * Check movable flag before taking the page lock because

	 * Check for movable_ops pages before taking the page lock because

	 * we use non-atomic bitops on newly allocated page flags so

	 * unconditionally grabbing the lock ruins page's owner side.

	 *

	 * Note that once a page has movable_ops, it will stay that way

	 * until the page was freed.

	 */

	if (unlikely(!__PageMovable(page)))

		goto out_putfolio;
@@ -108,7 +111,8 @@ bool isolate_movable_ops_page(struct page *page, isolate_mode_t mode) 
	if (unlikely(!folio_trylock(folio)))

		goto out_putfolio;



	if (!PageMovable(page) || PageIsolated(page))

	VM_WARN_ON_ONCE_PAGE(!__PageMovable(page), page);

	if (PageIsolated(page))

		goto out_no_isolated;



	mops = page_movable_ops(page);
@@ -149,10 +153,9 @@ static void putback_movable_ops_page(struct page *page) 
	 */

	struct folio *folio = page_folio(page);



	VM_WARN_ON_ONCE_PAGE(!__PageMovable(page), 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);
@@ -191,9 +194,8 @@ static int migrate_movable_ops_page(struct page *dst, struct page *src, 
{

	int rc = MIGRATEPAGE_SUCCESS;



	VM_WARN_ON_ONCE_PAGE(!__PageMovable(src), src);

	VM_WARN_ON_ONCE_PAGE(!PageIsolated(src), src);

	/* If the page was released by it's owner, there is nothing to do. */

	if (PageMovable(src))

	rc = page_movable_ops(src)->migrate_page(dst, src, mode);

	if (rc == MIGRATEPAGE_SUCCESS)

		ClearPageIsolated(src);