--- old/src/hotspot/share/runtime/globals.hpp	2018-07-19 11:58:51.035281735 +0100
+++ new/src/hotspot/share/runtime/globals.hpp	2018-07-19 11:58:50.764280919 +0100
@@ -2643,6 +2643,9 @@
   experimental(bool, UseSwitchProfiling, true,                              \
           "leverage profiling for table/lookup switch")                     \
                                                                             \
+  notproduct(bool, TraceMemoryWriteback, false,                             \
+          "Trace memory writeback operations")                              \
+                                                                            \
   JFR_ONLY(product(bool, FlightRecorder, false,                             \
           "Enable Flight Recorder"))                                        \
                                                                             \