1 files changed, 11 insertions, 2 deletions

diff --git a/mm/swap.c b/mm/swap.c
index 77825883298f..6310dc2008ff 100644
--- a/mm/swap.c
+++ b/mm/swap.c
@@ -446,13 +446,22 @@ void mark_page_accessed(struct page *page)
 }
 EXPORT_SYMBOL(mark_page_accessed);
 
+/*
+ * Order of operations is important: flush the pagevec when it's already
+ * full, not when adding the last page, to make sure that last page is
+ * not added to the LRU directly when passed to this function. Because
+ * mark_page_accessed() (called after this when writing) only activates
+ * pages that are on the LRU, linear writes in subpage chunks would see
+ * every PAGEVEC_SIZE page activated, which is unexpected.
+ */
 void __lru_cache_add(struct page *page, enum lru_list lru)
 {
         struct pagevec *pvec = &get_cpu_var(lru_add_pvecs)[lru];
 
         page_cache_get(page);
-        if (!pagevec_add(pvec, page))
+        if (!pagevec_space(pvec))
                 __pagevec_lru_add(pvec, lru);
+        pagevec_add(pvec, page);
         put_cpu_var(lru_add_pvecs);
 }
 EXPORT_SYMBOL(__lru_cache_add);
@@ -742,7 +751,7 @@ void lru_add_page_tail(struct page *page, struct page *page_tail,
 
         SetPageLRU(page_tail);
 
-        if (page_evictable(page_tail, NULL)) {
+        if (page_evictable(page_tail)) {
                 if (PageActive(page)) {
                         SetPageActive(page_tail);
                         active = 1;