--- a/hotspot/src/share/vm/runtime/handles.hpp	Wed May 17 23:36:19 2017 +0200
+++ b/hotspot/src/share/vm/runtime/handles.hpp	Thu May 18 08:17:52 2017 -0400
@@ -126,6 +126,8 @@
 
 // Metadata Handles.  Unlike oop Handles these are needed to prevent metadata
 // from being reclaimed by RedefineClasses.
+// Metadata Handles should be passed around as const references to avoid copy construction
+// and destruction for parameters.
 
 // Specific Handles for different oop types
 #define DEF_METADATA_HANDLE(name, type)          \