1 files changed, 79 insertions, 11 deletions

diff --git a/mm/swap.c b/mm/swap.c
index ab498ea..bbc1ce9 100644
--- a/mm/swap.c
+++ b/mm/swap.c
@@ -271,27 +271,94 @@ static void update_page_reclaim_stat(struct zone *zone, struct page *page,
 }
 
 /*
- * FIXME: speed this up?
+ * A page will go to active list either by activate_page or putback_lru_page.
+ * In the activate_page case, the page hasn't active bit set. The page might
+ * not in LRU list because it's isolated before it gets a chance to be moved to
+ * active list. The window is small because pagevec just stores several pages.
+ * For such case, we do nothing for such page.
+ * In the putback_lru_page case, the page isn't in lru list but has active
+ * bit set
  */
-void activate_page(struct page *page)
+static void __activate_page(struct page *page, void *arg)
 {
 	struct zone *zone = page_zone(page);
+	int file = page_is_file_cache(page);
+	int lru = page_lru_base_type(page);
+	bool putback = !PageLRU(page);
 
-	spin_lock_irq(&zone->lru_lock);
-	if (PageLRU(page) && !PageActive(page) && !PageUnevictable(page)) {
-		int file = page_is_file_cache(page);
-		int lru = page_lru_base_type(page);
+	/* The page is isolated before it's moved to active list */
+	if (!PageLRU(page) && !PageActive(page))
+		return;
+	if ((PageLRU(page) && PageActive(page)) || PageUnevictable(page))
+		return;
+
+	if (!putback)
 		del_page_from_lru_list(zone, page, lru);
+	else
+		SetPageLRU(page);
 
-		SetPageActive(page);
-		lru += LRU_ACTIVE;
-		add_page_to_lru_list(zone, page, lru);
-		__count_vm_event(PGACTIVATE);
+	SetPageActive(page);
+	lru += LRU_ACTIVE;
+	add_page_to_lru_list(zone, page, lru);
+
+	if (putback)
+		return;
+	__count_vm_event(PGACTIVATE);
+	update_page_reclaim_stat(zone, page, file, 1);
+}
+
+#ifdef CONFIG_SMP
+static DEFINE_PER_CPU(struct pagevec, activate_page_pvecs);
+
+static void activate_page_drain(int cpu)
+{
+	struct pagevec *pvec = &per_cpu(activate_page_pvecs, cpu);
+
+	if (pagevec_count(pvec))
+		pagevec_lru_move_fn(pvec, __activate_page, NULL);
+}
+
+void activate_page(struct page *page)
+{
+	if (PageLRU(page) && !PageActive(page) && !PageUnevictable(page)) {
+		struct pagevec *pvec = &get_cpu_var(activate_page_pvecs);
+
+		page_cache_get(page);
+		if (!pagevec_add(pvec, page))
+			pagevec_lru_move_fn(pvec, __activate_page, NULL);
+		put_cpu_var(activate_page_pvecs);
+	}
+}
 
-		update_page_reclaim_stat(zone, page, file, 1);
+/* Caller should hold zone->lru_lock */
+int putback_active_lru_page(struct zone *zone, struct page *page)
+{
+	struct pagevec *pvec = &get_cpu_var(activate_page_pvecs);
+
+	if (!pagevec_add(pvec, page)) {
+		spin_unlock_irq(&zone->lru_lock);
+		pagevec_lru_move_fn(pvec, __activate_page, NULL);
+		spin_lock_irq(&zone->lru_lock);
 	}
+	put_cpu_var(activate_page_pvecs);
+	return 1;
+}
+
+#else
+static inline void activate_page_drain(int cpu)
+{
+}
+
+void activate_page(struct page *page)
+{
+	struct zone *zone = page_zone(page);
+
+	spin_lock_irq(&zone->lru_lock);
+	if (PageLRU(page) && !PageActive(page) && !PageUnevictable(page))
+		__activate_page(page, NULL);
 	spin_unlock_irq(&zone->lru_lock);
 }
+#endif
 
 /*
  * Mark a page as having seen activity.
@@ -390,6 +457,7 @@ static void drain_cpu_pagevecs(int cpu)
 		pagevec_move_tail(pvec);
 		local_irq_restore(flags);
 	}
+	activate_page_drain(cpu);
 }
 
 void lru_add_drain(void)