mm: remove PageUnevictable

There is only one caller of PageUnevictable() left; convert it to call
folio_test_unevictable() and remove all the page accessors.

Link: https://lkml.kernel.org/r/20240821193445.2294269-6-willy@infradead.orgSigned-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

include/linux/page-flags.h

@@ -580,9 +580,9 @@ FOLIO_CLEAR_FLAG(swapcache, FOLIO_HEAD_PAGE)
 FOLIO_FLAG_FALSE(swapcache)
 #endif
 
-PAGEFLAG(Unevictable, unevictable, PF_HEAD)
-	__CLEARPAGEFLAG(Unevictable, unevictable, PF_HEAD)
-	TESTCLEARFLAG(Unevictable, unevictable, PF_HEAD)
+FOLIO_FLAG(unevictable, FOLIO_HEAD_PAGE)
+	__FOLIO_CLEAR_FLAG(unevictable, FOLIO_HEAD_PAGE)
+	FOLIO_TEST_CLEAR_FLAG(unevictable, FOLIO_HEAD_PAGE)
 
 #ifdef CONFIG_MMU
 PAGEFLAG(Mlocked, mlocked, PF_NO_TAIL)

mm/huge_memory.c

@@ -2932,25 +2932,25 @@ static void remap_page(struct folio *folio, unsigned long nr)
 	}
 }
 
-static void lru_add_page_tail(struct page *head, struct page *tail,
+static void lru_add_page_tail(struct folio *folio, struct page *tail,
 		struct lruvec *lruvec, struct list_head *list)
 {
-	VM_BUG_ON_PAGE(!PageHead(head), head);
-	VM_BUG_ON_PAGE(PageLRU(tail), head);
+	VM_BUG_ON_FOLIO(!folio_test_large(folio), folio);
+	VM_BUG_ON_FOLIO(PageLRU(tail), folio);
 	lockdep_assert_held(&lruvec->lru_lock);
 
 	if (list) {
 		/* page reclaim is reclaiming a huge page */
-		VM_WARN_ON(PageLRU(head));
+		VM_WARN_ON(folio_test_lru(folio));
 		get_page(tail);
 		list_add_tail(&tail->lru, list);
 	} else {
 		/* head is still on lru (and we have it frozen) */
-		VM_WARN_ON(!PageLRU(head));
-		if (PageUnevictable(tail))
+		VM_WARN_ON(!folio_test_lru(folio));
+		if (folio_test_unevictable(folio))
 			tail->mlock_count = 0;
 		else
-			list_add_tail(&tail->lru, &head->lru);
+			list_add_tail(&tail->lru, &folio->lru);
 		SetPageLRU(tail);
 	}
 }
@@ -3049,7 +3049,7 @@ static void __split_huge_page_tail(struct folio *folio, int tail,
 	 * pages to show after the currently processed elements - e.g.
 	 * migrate_pages
 	 */
-	lru_add_page_tail(head, page_tail, lruvec, list);
+	lru_add_page_tail(folio, page_tail, lruvec, list);
 }
 
 static void __split_huge_page(struct page *page, struct list_head *list,