--- old/src/hotspot/share/gc/g1/g1CollectedHeap.cpp	2018-10-18 18:01:51.000000000 -0400
+++ new/src/hotspot/share/gc/g1/g1CollectedHeap.cpp	2018-10-18 18:01:51.000000000 -0400
@@ -644,7 +644,7 @@
         curr_region->set_closed_archive();
       }
       _hr_printer.alloc(curr_region);
-      _archive_set.add(curr_region);
+      archive_set_add(curr_region);
       HeapWord* top;
       HeapRegion* next_region;
       if (curr_region != last_region) {
@@ -1606,7 +1606,6 @@
   os::enable_vtime();
 
   // Necessary to satisfy locking discipline assertions.
-
   MutexLocker x(Heap_lock);
 
   // While there are no constraints in the GC code that HeapWordSize
@@ -1833,6 +1832,9 @@
 }
 
 void G1CollectedHeap::post_initialize() {
+  // Necessary to satisfy locking discipline assertions.
+  MutexLockerEx x(Heap_lock);
+
   CollectedHeap::post_initialize();
   ref_processing_init();
 }
@@ -2899,9 +2901,7 @@
     active_workers = workers()->update_active_workers(active_workers);
     log_info(gc,task)("Using %u workers of %u for evacuation", active_workers, workers()->total_workers());
 
-    G1MonitoringScope ms(g1mm(),
-                         false /* full_gc */,
-                         collector_state()->yc_type() == Mixed /* all_memory_pools_affected */);
+    G1MonitoringScope ms(g1mm(), false /* full_gc */, collector_state()->yc_type() == Mixed /* mixed_gc */);
 
     G1HeapTransition heap_transition(this);
     size_t heap_used_bytes_before_gc = used();