--- a/src/hotspot/share/runtime/arguments.cpp	Thu Oct 31 07:53:16 2019 +0100
+++ b/src/hotspot/share/runtime/arguments.cpp	Tue Nov 05 09:37:20 2019 +0800
@@ -4029,6 +4029,12 @@
   no_shared_spaces("CDS Disabled");
 #endif // INCLUDE_CDS
 
+#ifndef TIERED
+  if (FLAG_IS_CMDLINE(CompilationMode)) {
+    warning("CompilationMode has no effect in non-tiered VMs");
+  }
+#endif
+
   return JNI_OK;
 }