[PATCH 02/13] mm: use page_off_lru()

[Yu Zhao <yuzhao@xxxxxxxxxx>]

This patch replaces the only open-coded __ClearPageActive() with
page_off_lru(). There is no open-coded __ClearPageUnevictable()s.

Before this patch, we have:
	__ClearPageActive()
	add_page_to_lru_list()

After this patch, we have:
	page_off_lru()
		if PageUnevictable()
			__ClearPageUnevictable()
		else if PageActive()
			__ClearPageActive()
	add_page_to_lru_list()

Checking PageUnevictable() shouldn't be a problem because these two
flags are mutually exclusive. Leaking either will trigger bad_page().

Signed-off-by: Yu Zhao <yuzhao@xxxxxxxxxx>
---
 mm/vmscan.c | 6 +-----
 1 file changed, 1 insertion(+), 5 deletions(-)

diff --git a/mm/vmscan.c b/mm/vmscan.c
index 503fc5e1fe32..f257d2f61574 100644
--- a/mm/vmscan.c
+++ b/mm/vmscan.c
@@ -1845,7 +1845,6 @@ static unsigned noinline_for_stack move_pages_to_lru(struct lruvec *lruvec,
 	int nr_pages, nr_moved = 0;
 	LIST_HEAD(pages_to_free);
 	struct page *page;
-	enum lru_list lru;
 
 	while (!list_empty(list)) {
 		page = lru_to_page(list);
@@ -1860,14 +1859,11 @@ static unsigned noinline_for_stack move_pages_to_lru(struct lruvec *lruvec,
 		lruvec = mem_cgroup_page_lruvec(page, pgdat);
 
 		SetPageLRU(page);
-		lru = page_lru(page);
-
 		add_page_to_lru_list(page, lruvec, lru);
 
 		if (put_page_testzero(page)) {
 			__ClearPageLRU(page);
-			__ClearPageActive(page);
-			del_page_from_lru_list(page, lruvec, lru);
+			del_page_from_lru_list(page, lruvec, page_off_lru(page));
 
 			if (unlikely(PageCompound(page))) {
 				spin_unlock_irq(&pgdat->lru_lock);
-- 
2.28.0.681.g6f77f65b4e-goog