--- old/src/hotspot/share/gc/g1/g1YoungRemSetSamplingThread.hpp	2018-10-18 16:42:34.962336823 +0200
+++ new/src/hotspot/share/gc/g1/g1YoungRemSetSamplingThread.hpp	2018-10-18 16:42:34.542323895 +0200
@@ -43,6 +43,10 @@
 private:
   Monitor _monitor;
 
+  double _last_periodic_gc_attempt_s;
+
+  double _vtime_accum;  // Accumulated virtual time.
+
   void sample_young_list_rs_lengths();
 
   void run_service();
@@ -50,7 +54,7 @@
 
   void sleep_before_next_cycle();
 
-  double _vtime_accum;  // Accumulated virtual time.
+  bool should_start_periodic_gc();
 
 public:
   G1YoungRemSetSamplingThread();