--- old/src/hotspot/share/gc/g1/g1SurvivorRegions.cpp	2019-11-06 13:48:42.597572589 -0800
+++ new/src/hotspot/share/gc/g1/g1SurvivorRegions.cpp	2019-11-06 13:48:42.205572577 -0800
@@ -30,17 +30,23 @@
 
 G1SurvivorRegions::G1SurvivorRegions() :
   _regions(new (ResourceObj::C_HEAP, mtGC) GrowableArray<HeapRegion*>(8, true, mtGC)),
-  _used_bytes(0) {}
+  _used_bytes(0),
+  _regions_on_node() {}
 
-void G1SurvivorRegions::add(HeapRegion* hr) {
+uint G1SurvivorRegions::add(HeapRegion* hr) {
   assert(hr->is_survivor(), "should be flagged as survivor region");
   _regions->append(hr);
+  return _regions_on_node.add(hr);
 }
 
 uint G1SurvivorRegions::length() const {
   return (uint)_regions->length();
 }
 
+uint G1SurvivorRegions::regions_on_node(uint node_index) const {
+  return _regions_on_node.count(node_index);
+}
+
 void G1SurvivorRegions::convert_to_eden() {
   for (GrowableArrayIterator<HeapRegion*> it = _regions->begin();
        it != _regions->end();
@@ -54,6 +60,7 @@
 void G1SurvivorRegions::clear() {
   _regions->clear();
   _used_bytes = 0;
+  _regions_on_node.clear();
 }
 
 void G1SurvivorRegions::add_used_bytes(size_t used_bytes) {