diff --git a/sys/vm/vm_page.c b/sys/vm/vm_page.c
--- a/sys/vm/vm_page.c
+++ b/sys/vm/vm_page.c
@@ -4436,7 +4436,8 @@
 	VM_OBJECT_ASSERT_WLOCKED(m->object);
 	vm_page_assert_xbusied(m);
 
-	if (advice == MADV_FREE)
+	switch (advice) {
+	case MADV_FREE:
 		/*
 		 * Mark the page clean.  This will allow the page to be freed
 		 * without first paging it out.  MADV_FREE pages are often
@@ -4444,15 +4445,19 @@
 		 * would result in a page fault on a later access.
 		 */
 		vm_page_undirty(m);
-	else if (advice != MADV_DONTNEED) {
-		if (advice == MADV_WILLNEED)
-			vm_page_activate(m);
+		break;
+	case MADV_DONTNEED:
+		if (m->dirty == 0 && pmap_is_modified(m))
+			vm_page_dirty(m);
+		break;
+	case MADV_WILLNEED:
+		vm_page_activate(m);
+		return;
+	default:
+		/* Do nothing. */
 		return;
 	}
 
-	if (advice != MADV_FREE && m->dirty == 0 && pmap_is_modified(m))
-		vm_page_dirty(m);
-
 	/*
 	 * Clear any references to the page.  Otherwise, the page daemon will
 	 * immediately reactivate the page.