vmscan: convert lazy freeing to folios

Remove a hidden call to compound_head(), and account nr_pages instead of a
single page.  This matches the code in lru_lazyfree_fn() that accounts
nr_pages to PGLAZYFREE.

Link: https://lkml.kernel.org/r/20220504182857.4013401-12-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

1 files changed, 9 insertions, 9 deletions

diff --git a/mm/vmscan.c b/mm/vmscan.c
index 00b985caf40d..972557e2fb92 100644
--- a/mm/vmscan.c
+++ b/mm/vmscan.c
@@ -1902,20 +1902,20 @@ retry:
 			}
 		}
 
-		if (PageAnon(page) && !PageSwapBacked(page)) {
+		if (folio_test_anon(folio) && !folio_test_swapbacked(folio)) {
 			/* follow __remove_mapping for reference */
-			if (!page_ref_freeze(page, 1))
+			if (!folio_ref_freeze(folio, 1))
 				goto keep_locked;
 			/*
-			 * The page has only one reference left, which is
+			 * The folio has only one reference left, which is
 			 * from the isolation. After the caller puts the
-			 * page back on lru and drops the reference, the
-			 * page will be freed anyway. It doesn't matter
-			 * which lru it goes. So we don't bother checking
-			 * PageDirty here.
+			 * folio back on the lru and drops the reference, the
+			 * folio will be freed anyway. It doesn't matter
+			 * which lru it goes on. So we don't bother checking
+			 * the dirty flag here.
 			 */
-			count_vm_event(PGLAZYFREED);
-			count_memcg_page_event(page, PGLAZYFREED);
+			count_vm_events(PGLAZYFREED, nr_pages);
+			count_memcg_folio_events(folio, PGLAZYFREED, nr_pages);
 		} else if (!mapping || !__remove_mapping(mapping, folio, true,
 							 sc->target_mem_cgroup))
 			goto keep_locked;