Commit 49f51859 authored by Huang Ying's avatar Huang Ying Committed by Andrew Morton
Browse files

migrate: convert unmap_and_move() to use folios 

Patch series "migrate: convert migrate_pages()/unmap_and_move() to use
folios", v2.

The conversion is quite straightforward, just replace the page API to the
corresponding folio API.  migrate_pages() and unmap_and_move() mostly work
with folios (head pages) only.


This patch (of 2):

Quite straightforward, the page functions are converted to corresponding
folio functions.  Same for comments.

Link: https://lkml.kernel.org/r/20221109012348.93849-1-ying.huang@intel.com
Link: https://lkml.kernel.org/r/20221109012348.93849-2-ying.huang@intel.com


Signed-off-by: default avatar"Huang, Ying" <ying.huang@intel.com>
Reviewed-by: default avatarYang Shi <shy828301@gmail.com>
Reviewed-by: default avatarZi Yan <ziy@nvidia.com>
Reviewed-by: default avatarMatthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: default avatarBaolin Wang <baolin.wang@linux.alibaba.com>
Cc: Oscar Salvador <osalvador@suse.de>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
parent 16fd6b31

mm/migrate.c

+27 −27
Original line number Diff line number Diff line
@@ -1150,79 +1150,79 @@ static int __unmap_and_move(struct folio *src, struct folio *dst, 
}



/*

 * Obtain the lock on page, remove all ptes and migrate the page

 * to the newly allocated page in newpage.

 * Obtain the lock on folio, remove all ptes and migrate the folio

 * to the newly allocated folio in dst.

 */

static int unmap_and_move(new_page_t get_new_page,

				   free_page_t put_new_page,

				   unsigned long private, struct page *page,

				   unsigned long private, struct folio *src,

				   int force, enum migrate_mode mode,

				   enum migrate_reason reason,

				   struct list_head *ret)

{

	struct folio *dst, *src = page_folio(page);

	struct folio *dst;

	int rc = MIGRATEPAGE_SUCCESS;

	struct page *newpage = NULL;



	if (!thp_migration_supported() && PageTransHuge(page))

	if (!thp_migration_supported() && folio_test_transhuge(src))

		return -ENOSYS;



	if (page_count(page) == 1) {

		/* Page was freed from under us. So we are done. */

		ClearPageActive(page);

		ClearPageUnevictable(page);

	if (folio_ref_count(src) == 1) {

		/* Folio was freed from under us. So we are done. */

		folio_clear_active(src);

		folio_clear_unevictable(src);

		/* free_pages_prepare() will clear PG_isolated. */

		goto out;

	}



	newpage = get_new_page(page, private);

	newpage = get_new_page(&src->page, private);

	if (!newpage)

		return -ENOMEM;

	dst = page_folio(newpage);



	newpage->private = 0;

	dst->private = 0;

	rc = __unmap_and_move(src, dst, force, mode);

	if (rc == MIGRATEPAGE_SUCCESS)

		set_page_owner_migrate_reason(newpage, reason);

		set_page_owner_migrate_reason(&dst->page, reason);



out:

	if (rc != -EAGAIN) {

		/*

		 * A page that has been migrated has all references

		 * removed and will be freed. A page that has not been

		 * A folio that has been migrated has all references

		 * removed and will be freed. A folio that has not been

		 * migrated will have kept its references and be restored.

		 */

		list_del(&page->lru);

		list_del(&src->lru);

	}



	/*

	 * If migration is successful, releases reference grabbed during

	 * isolation. Otherwise, restore the page to right list unless

	 * isolation. Otherwise, restore the folio to right list unless

	 * we want to retry.

	 */

	if (rc == MIGRATEPAGE_SUCCESS) {

		/*

		 * Compaction can migrate also non-LRU pages which are

		 * Compaction can migrate also non-LRU folios which are

		 * not accounted to NR_ISOLATED_*. They can be recognized

		 * as __PageMovable

		 * as __folio_test_movable

		 */

		if (likely(!__PageMovable(page)))

			mod_node_page_state(page_pgdat(page), NR_ISOLATED_ANON +

					page_is_file_lru(page), -thp_nr_pages(page));

		if (likely(!__folio_test_movable(src)))

			mod_node_page_state(folio_pgdat(src), NR_ISOLATED_ANON +

					folio_is_file_lru(src), -folio_nr_pages(src));



		if (reason != MR_MEMORY_FAILURE)

			/*

			 * We release the page in page_handle_poison.

			 * We release the folio in page_handle_poison.

			 */

			put_page(page);

			folio_put(src);

	} else {

		if (rc != -EAGAIN)

			list_add_tail(&page->lru, ret);

			list_add_tail(&src->lru, ret);



		if (put_new_page)

			put_new_page(newpage, private);

			put_new_page(&dst->page, private);

		else

			put_page(newpage);

			folio_put(dst);

	}



	return rc;
@@ -1459,7 +1459,7 @@ int migrate_pages(struct list_head *from, new_page_t get_new_page, 
						&ret_pages);

			else

				rc = unmap_and_move(get_new_page, put_new_page,

						private, page, pass > 2, mode,

						private, page_folio(page), pass > 2, mode,

						reason, &ret_pages);

			/*

			 * The rules are: