diff -r b4fd7e078c54 -r 1b8c45b8216a src/share/vm/gc_implementation/g1/g1CollectedHeap.cpp
--- a/src/share/vm/gc_implementation/g1/g1CollectedHeap.cpp	Thu Feb 27 19:01:32 2020 +0000
+++ b/src/share/vm/gc_implementation/g1/g1CollectedHeap.cpp	Tue Mar 03 12:57:23 2020 +0000
@@ -3579,6 +3579,28 @@
 }
 #endif // PRODUCT
 
+G1HeapSummary G1CollectedHeap::create_g1_heap_summary() {
+
+  size_t eden_used_bytes = _young_list->eden_used_bytes();
+  size_t survivor_used_bytes = _young_list->survivor_used_bytes();
+  size_t heap_used = Heap_lock->owned_by_self() ? used() : used_unlocked();
+
+  size_t eden_capacity_bytes =
+    (g1_policy()->young_list_target_length() * HeapRegion::GrainBytes) - survivor_used_bytes;
+
+  VirtualSpaceSummary heap_summary = create_heap_space_summary();
+  return G1HeapSummary(heap_summary, heap_used, eden_used_bytes,
+                       eden_capacity_bytes, survivor_used_bytes, num_regions());
+}
+
+void G1CollectedHeap::trace_heap(GCWhen::Type when, GCTracer* gc_tracer) {
+  const G1HeapSummary& heap_summary = create_g1_heap_summary();
+  gc_tracer->report_gc_heap_summary(when, heap_summary);
+
+  const MetaspaceSummary& metaspace_summary = create_metaspace_summary();
+  gc_tracer->report_metaspace_summary(when, metaspace_summary);
+}
+
 G1CollectedHeap* G1CollectedHeap::heap() {
   assert(_sh->kind() == CollectedHeap::G1CollectedHeap,
          "not a garbage-first heap");
@@ -4096,7 +4118,7 @@
         g1_policy()->print_collection_set(g1_policy()->inc_cset_head(), gclog_or_tty);
 #endif // YOUNG_LIST_VERBOSE
 
-        g1_policy()->record_collection_pause_start(sample_start_time_sec);
+        g1_policy()->record_collection_pause_start(sample_start_time_sec, *_gc_tracer_stw);
 
         double scan_wait_start = os::elapsedTime();
         // We have to wait until the CM threads finish scanning the