From ef2a2cbdda7e9d084a85846770fcc844958881f6 Mon Sep 17 00:00:00 2001 From: Naoya Horiguchi Date: Wed, 31 Jul 2013 13:53:37 -0700 Subject: [PATCH] mm/swap.c: clear PageActive before adding pages onto unevictable list As a result of commit 13f7f78981e4 ("mm: pagevec: defer deciding which LRU to add a page to until pagevec drain time"), pages on unevictable lists can have both of PageActive and PageUnevictable set. This is not only confusing, but also corrupts page migration and shrink_[in]active_list. This patch fixes the problem by adding ClearPageActive before adding pages into unevictable list. It also cleans up VM_BUG_ONs. Signed-off-by: Naoya Horiguchi Cc: Mel Gorman Cc: KOSAKI Motohiro Cc: "Kirill A. Shutemov" Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- mm/swap.c | 9 ++------- 1 file changed, 2 insertions(+), 7 deletions(-) diff --git a/mm/swap.c b/mm/swap.c index 4a1d0d2c52fa..d3982c062629 100644 --- a/mm/swap.c +++ b/mm/swap.c @@ -512,12 +512,7 @@ EXPORT_SYMBOL(__lru_cache_add); */ void lru_cache_add(struct page *page) { - if (PageActive(page)) { - VM_BUG_ON(PageUnevictable(page)); - } else if (PageUnevictable(page)) { - VM_BUG_ON(PageActive(page)); - } - + VM_BUG_ON(PageActive(page) && PageUnevictable(page)); VM_BUG_ON(PageLRU(page)); __lru_cache_add(page); } @@ -539,6 +534,7 @@ void add_page_to_unevictable_list(struct page *page) spin_lock_irq(&zone->lru_lock); lruvec = mem_cgroup_page_lruvec(page, zone); + ClearPageActive(page); SetPageUnevictable(page); SetPageLRU(page); add_page_to_lru_list(page, lruvec, LRU_UNEVICTABLE); @@ -833,7 +829,6 @@ static void __pagevec_lru_add_fn(struct page *page, struct lruvec *lruvec, int active = PageActive(page); enum lru_list lru = page_lru(page); - VM_BUG_ON(PageUnevictable(page)); VM_BUG_ON(PageLRU(page)); SetPageLRU(page);