[RFC v2 PATCH 07/17] mm: Allow deferred splitting of arbitrary large anon folios

[Ryan Roberts <ryan.roberts@arm.com>]

With the introduction of large folios for anonymous memory, we would
like to be able to split them when they have unmapped subpages, in order
to free those unused pages under memory pressure. So remove the
artificial requirement that the large folio needed to be at least
PMD-sized.

Signed-off-by: Ryan Roberts <ryan.roberts@arm.com>
---
 mm/rmap.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/mm/rmap.c b/mm/rmap.c
index d563d979c005..5148a484f915 100644
--- a/mm/rmap.c
+++ b/mm/rmap.c
@@ -1470,7 +1470,7 @@ void page_remove_rmap(struct page *page, struct vm_area_struct *vma,
 		 * page of the folio is unmapped and at least one page
 		 * is still mapped.
 		 */
-		if (folio_test_pmd_mappable(folio) && folio_test_anon(folio))
+		if (folio_test_large(folio) && folio_test_anon(folio))
 			if (!compound || nr < nr_pmdmapped)
 				deferred_split_folio(folio);
 	}
--
2.25.1