--- old/src/share/vm/gc_implementation/g1/heapRegion.cpp	2019-01-28 17:43:38.000000000 +0800
+++ new/src/share/vm/gc_implementation/g1/heapRegion.cpp	2019-01-28 17:43:38.000000000 +0800
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2001, 2015, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2001, 2019, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -31,6 +31,7 @@
 #include "gc_implementation/g1/heapRegionBounds.inline.hpp"
 #include "gc_implementation/g1/heapRegionRemSet.hpp"
 #include "gc_implementation/g1/heapRegionManager.inline.hpp"
+#include "gc_implementation/g1/heapRegionTracer.hpp"
 #include "gc_implementation/shared/liveRange.hpp"
 #include "memory/genOopClosures.inline.hpp"
 #include "memory/iterator.hpp"
@@ -217,7 +218,9 @@
          "Should be normal before the humongous object allocation");
   assert(top() == bottom(), "should be empty");
   assert(bottom() <= new_top && new_top <= new_end, "pre-condition");
-
+  if (EnableJFR) {
+    report_region_type_change(G1HeapRegionTraceType::StartsHumongous);
+  }
   _type.set_starts_humongous();
   _humongous_start_region = this;
 
@@ -231,7 +234,9 @@
          "Should be normal before the humongous object allocation");
   assert(top() == bottom(), "should be empty");
   assert(first_hr->startsHumongous(), "pre-condition");
-
+  if (EnableJFR) {
+    report_region_type_change(G1HeapRegionTraceType::ContinuesHumongous);
+  }
   _type.set_continues_humongous();
   _humongous_start_region = first_hr;
 }
@@ -303,6 +308,16 @@
   record_timestamp();
 }
 
+void HeapRegion::report_region_type_change(G1HeapRegionTraceType::Type to) {
+  assert(EnableJFR, "sanity check");
+  HeapRegionTracer::send_region_type_change(_hrm_index,
+                                            get_trace_type(),
+                                            to,
+                                            (uintptr_t)bottom(),
+                                            used());
+}
+
+
 CompactibleSpace* HeapRegion::next_compaction_space() const {
   return G1CollectedHeap::heap()->next_compaction_region(this);
 }