diff --git a/mm/swap.c b/mm/swap.c
index 26fc9b5..a3fc028 100644
--- a/mm/swap.c
+++ b/mm/swap.c
@@ -321,11 +321,6 @@
 {
 }
 
-static bool need_activate_page_drain(int cpu)
-{
-	return false;
-}
-
 void activate_page(struct page *page)
 {
 	struct zone *zone = page_zone(page);
@@ -654,13 +649,15 @@
 	put_cpu();
 }
 
+#ifdef CONFIG_SMP
+
+static DEFINE_PER_CPU(struct work_struct, lru_add_drain_work);
+
 static void lru_add_drain_per_cpu(struct work_struct *dummy)
 {
 	lru_add_drain();
 }
 
-static DEFINE_PER_CPU(struct work_struct, lru_add_drain_work);
-
 /*
  * Doesn't need any cpu hotplug locking because we do rely on per-cpu
  * kworkers being shut down before our page_alloc_cpu_dead callback is
@@ -703,6 +700,12 @@
 
 	mutex_unlock(&lock);
 }
+#else
+void lru_add_drain_all(void)
+{
+	lru_add_drain();
+}
+#endif
 
 /**
  * release_pages - batched put_page()