mm/swap: convert put_pages_list to use folios

Pages linked through the LRU list cannot be tail pages as ->compound_head
is in a union with one of the words of the list_head, and they cannot
be ZONE_DEVICE pages as ->pgmap is in a union with the same word.
Saves 60 bytes of text by removing a call to page_is_fake_head().

Link: https://lkml.kernel.org/r/20220617175020.717127-15-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

diff --git a/mm/swap.c b/mm/swap.c
index 417dc32534c105bb93a79b61481b076c4930a713..a5a91aec83da364d916d305499382b9c8573ca3d 100644 (file)
--- a/mm/swap.c
+++ b/mm/swap.c
@@ -138,19 +138,19 @@ EXPORT_SYMBOL(__put_page);
  */
 void put_pages_list(struct list_head *pages)
 {
-       struct page *page, *next;
+       struct folio *folio, *next;
 
-       list_for_each_entry_safe(page, next, pages, lru) {
-               if (!put_page_testzero(page)) {
-                       list_del(&page->lru);
+       list_for_each_entry_safe(folio, next, pages, lru) {
+               if (!folio_put_testzero(folio)) {
+                       list_del(&folio->lru);
                        continue;
                }
-               if (PageHead(page)) {
-                       list_del(&page->lru);
-                       __put_compound_page(page);
+               if (folio_test_large(folio)) {
+                       list_del(&folio->lru);
+                       __put_compound_page(&folio->page);
                        continue;
                }
-               /* Cannot be PageLRU because it's passed to us using the lru */
+               /* LRU flag must be clear because it's passed using the lru */
        }
 
        free_unref_page_list(pages);