[RFC PATCH 15/18] mm: Convert free_pages_and_swap_cache() to use folios_put()

["Matthew Wilcox (Oracle)" <willy@infradead.org>]

Process the pages in batch-sized quantities instead of all-at-once.

Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
---
 mm/swap_state.c | 15 ++++++++++++---
 1 file changed, 12 insertions(+), 3 deletions(-)

diff --git a/mm/swap_state.c b/mm/swap_state.c
index b3b14bd0dd64..f68ddeb93698 100644
--- a/mm/swap_state.c
+++ b/mm/swap_state.c
@@ -14,6 +14,7 @@
 #include <linux/swapops.h>
 #include <linux/init.h>
 #include <linux/pagemap.h>
+#include <linux/pagevec.h>
 #include <linux/backing-dev.h>
 #include <linux/blkdev.h>
 #include <linux/migrate.h>
@@ -309,10 +310,18 @@ void free_page_and_swap_cache(struct page *page)
  */
 void free_pages_and_swap_cache(struct encoded_page **pages, int nr)
 {
+	struct folio_batch folios;
+
 	lru_add_drain();
-	for (int i = 0; i < nr; i++)
-		free_swap_cache(encoded_page_ptr(pages[i]));
-	release_pages(pages, nr);
+	folio_batch_init(&folios);
+	for (int i = 0; i < nr; i++) {
+		struct folio *folio = page_folio(encoded_page_ptr(pages[i]));
+		free_swap_cache(&folio->page);
+		if (folio_batch_add(&folios, folio) == 0)
+			folios_put(&folios);
+	}
+	if (folios.nr)
+		folios_put(&folios);
 }
 
 static inline bool swap_use_vma_readahead(void)
-- 
2.40.1