mm/vmscan: convert reclaim_pages() to use a folio

Remove a few hidden calls to compound_head, saving 76 bytes of text.

Link: https://lkml.kernel.org/r/20220617154248.700416-6-willy@infradead.orgSigned-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

mm/vmscan.c

@@ -2619,34 +2619,33 @@ static unsigned int reclaim_page_list(struct list_head *page_list,
 	return nr_reclaimed;
 }
 
-unsigned long reclaim_pages(struct list_head *page_list)
+unsigned long reclaim_pages(struct list_head *folio_list)
 {
 	int nid;
 	unsigned int nr_reclaimed = 0;
-	LIST_HEAD(node_page_list);
-	struct page *page;
+	LIST_HEAD(node_folio_list);
 	unsigned int noreclaim_flag;
 
-	if (list_empty(page_list))
+	if (list_empty(folio_list))
 		return nr_reclaimed;
 
 	noreclaim_flag = memalloc_noreclaim_save();
 
-	nid = page_to_nid(lru_to_page(page_list));
+	nid = folio_nid(lru_to_folio(folio_list));
 	do {
-		page = lru_to_page(page_list);
+		struct folio *folio = lru_to_folio(folio_list);
 
-		if (nid == page_to_nid(page)) {
-			ClearPageActive(page);
-			list_move(&page->lru, &node_page_list);
+		if (nid == folio_nid(folio)) {
+			folio_clear_active(folio);
+			list_move(&folio->lru, &node_folio_list);
 			continue;
 		}
 
-		nr_reclaimed += reclaim_page_list(&node_page_list, NODE_DATA(nid));
-		nid = page_to_nid(lru_to_page(page_list));
-	} while (!list_empty(page_list));
+		nr_reclaimed += reclaim_page_list(&node_folio_list, NODE_DATA(nid));
+		nid = folio_nid(lru_to_folio(folio_list));
+	} while (!list_empty(folio_list));
 
-	nr_reclaimed += reclaim_page_list(&node_page_list, NODE_DATA(nid));
+	nr_reclaimed += reclaim_page_list(&node_folio_list, NODE_DATA(nid));
 
 	memalloc_noreclaim_restore(noreclaim_flag);