--- old/src/hotspot/share/gc/z/zReferenceProcessor.cpp	2018-03-05 15:14:49.983963697 +0100
+++ new/src/hotspot/share/gc/z/zReferenceProcessor.cpp	2018-03-05 15:14:49.815956498 +0100
@@ -43,7 +43,7 @@
     _workers(workers),
     _soft_reference_policy(NULL),
     _encountered_count(),
-    _dropped_count(),
+    _discovered_count(),
     _enqueued_count(),
     _discovered_list(NULL),
     _pending_list(NULL),
@@ -180,6 +180,9 @@
 void ZReferenceProcessor::discover(oop obj, ReferenceType type) {
   log_trace(gc, ref)("Discovered Reference: " PTR_FORMAT " (%s)", p2i(obj), ReferenceTypeName[type]);
 
+  // Update statistics
+  _discovered_count.get()[type]++;
+
   // Mark referent finalizable
   if (should_mark_referent(type)) {
     oop* const referent_addr = (oop*)java_lang_ref_Reference::referent_addr(obj);
@@ -196,9 +199,6 @@
 oop ZReferenceProcessor::drop(oop obj, ReferenceType type) {
   log_trace(gc, ref)("Dropped Reference: " PTR_FORMAT " (%s)", p2i(obj), ReferenceTypeName[type]);
 
-  // Update statistics
-  _dropped_count.get()[type]++;
-
   // Keep referent alive
   keep_referent_alive(obj, type);
 
@@ -290,9 +290,9 @@
     }
   }
 
-  // Reset dropped
-  ZPerWorkerIterator<Counters> iter_dropped(&_dropped_count);
-  for (Counters* counters; iter_dropped.next(&counters);) {
+  // Reset discovered
+  ZPerWorkerIterator<Counters> iter_discovered(&_discovered_count);
+  for (Counters* counters; iter_discovered.next(&counters);) {
     for (int i = REF_SOFT; i <= REF_PHANTOM; i++) {
       (*counters)[i] = 0;
     }
@@ -309,7 +309,7 @@
 
 void ZReferenceProcessor::collect_statistics() {
   Counters encountered = {};
-  Counters dropped = {};
+  Counters discovered = {};
   Counters enqueued = {};
 
   // Sum encountered
@@ -320,11 +320,11 @@
     }
   }
 
-  // Sum dropped
-  ZPerWorkerConstIterator<Counters> iter_dropped(&_dropped_count);
-  for (const Counters* counters; iter_dropped.next(&counters);) {
+  // Sum discovered
+  ZPerWorkerConstIterator<Counters> iter_discovered(&_discovered_count);
+  for (const Counters* counters; iter_discovered.next(&counters);) {
     for (int i = REF_SOFT; i <= REF_PHANTOM; i++) {
-      dropped[i] += (*counters)[i];
+      discovered[i] += (*counters)[i];
     }
   }
 
@@ -337,16 +337,16 @@
   }
 
   // Update statistics
-  ZStatReferences::set_soft(encountered[REF_SOFT], dropped[REF_SOFT], enqueued[REF_SOFT]);
-  ZStatReferences::set_weak(encountered[REF_WEAK], dropped[REF_WEAK], enqueued[REF_WEAK]);
-  ZStatReferences::set_final(encountered[REF_FINAL], dropped[REF_FINAL], enqueued[REF_FINAL]);
-  ZStatReferences::set_phantom(encountered[REF_PHANTOM], dropped[REF_PHANTOM], enqueued[REF_PHANTOM]);
+  ZStatReferences::set_soft(encountered[REF_SOFT], discovered[REF_SOFT], enqueued[REF_SOFT]);
+  ZStatReferences::set_weak(encountered[REF_WEAK], discovered[REF_WEAK], enqueued[REF_WEAK]);
+  ZStatReferences::set_final(encountered[REF_FINAL], discovered[REF_FINAL], enqueued[REF_FINAL]);
+  ZStatReferences::set_phantom(encountered[REF_PHANTOM], discovered[REF_PHANTOM], enqueued[REF_PHANTOM]);
 
   // Trace statistics
-  const ReferenceProcessorStats stats(dropped[REF_SOFT] + enqueued[REF_SOFT],
-                                      dropped[REF_WEAK] + enqueued[REF_WEAK],
-                                      dropped[REF_FINAL] + enqueued[REF_FINAL],
-                                      dropped[REF_PHANTOM] + enqueued[REF_PHANTOM]);
+  const ReferenceProcessorStats stats(discovered[REF_SOFT],
+                                      discovered[REF_WEAK],
+                                      discovered[REF_FINAL],
+                                      discovered[REF_PHANTOM]);
   ZTracer::tracer()->report_gc_reference_stats(stats);
 }
 
--- old/src/hotspot/share/gc/z/zReferenceProcessor.hpp	2018-03-05 15:14:50.278976338 +0100
+++ new/src/hotspot/share/gc/z/zReferenceProcessor.hpp	2018-03-05 15:14:50.111969182 +0100
@@ -39,7 +39,7 @@
   ZWorkers* const      _workers;
   ReferencePolicy*     _soft_reference_policy;
   ZPerWorker<Counters> _encountered_count;
-  ZPerWorker<Counters> _dropped_count;
+  ZPerWorker<Counters> _discovered_count;
   ZPerWorker<Counters> _enqueued_count;
   ZPerWorker<oop>      _discovered_list;
   ZContended<oop>      _pending_list;
--- old/src/hotspot/share/gc/z/zStat.cpp	2018-03-05 15:14:50.563988551 +0100
+++ new/src/hotspot/share/gc/z/zStat.cpp	2018-03-05 15:14:50.395981352 +0100
@@ -1134,39 +1134,36 @@
 ZStatReferences::ZCount ZStatReferences::_final;
 ZStatReferences::ZCount ZStatReferences::_phantom;
 
-void ZStatReferences::set(ZCount* count, size_t encountered, size_t dropped, size_t enqueued) {
+void ZStatReferences::set(ZCount* count, size_t encountered, size_t discovered, size_t enqueued) {
   count->encountered = encountered;
-  count->discovered = dropped + enqueued;
-  count->dropped = dropped;
+  count->discovered = discovered;
   count->enqueued = enqueued;
 }
 
-void ZStatReferences::set_soft(size_t encountered, size_t dropped, size_t enqueued) {
-  set(&_soft, encountered, dropped, enqueued);
+void ZStatReferences::set_soft(size_t encountered, size_t discovered, size_t enqueued) {
+  set(&_soft, encountered, discovered, enqueued);
 }
 
-void ZStatReferences::set_weak(size_t encountered, size_t dropped, size_t enqueued) {
-  set(&_weak, encountered, dropped, enqueued);
+void ZStatReferences::set_weak(size_t encountered, size_t discovered, size_t enqueued) {
+  set(&_weak, encountered, discovered, enqueued);
 }
 
-void ZStatReferences::set_final(size_t encountered, size_t dropped, size_t enqueued) {
-  set(&_final, encountered, dropped, enqueued);
+void ZStatReferences::set_final(size_t encountered, size_t discovered, size_t enqueued) {
+  set(&_final, encountered, discovered, enqueued);
 }
 
-void ZStatReferences::set_phantom(size_t encountered, size_t dropped, size_t enqueued) {
-  set(&_phantom, encountered, dropped, enqueued);
+void ZStatReferences::set_phantom(size_t encountered, size_t discovered, size_t enqueued) {
+  set(&_phantom, encountered, discovered, enqueued);
 }
 
 void ZStatReferences::print(const char* name, const ZStatReferences::ZCount& ref) {
   log_info(gc, ref)("%s: "
                     SIZE_FORMAT " encountered, "
                     SIZE_FORMAT " discovered, "
-                    SIZE_FORMAT " dropped, "
                     SIZE_FORMAT " enqueued",
                     name,
                     ref.encountered,
                     ref.discovered,
-                    ref.dropped,
                     ref.enqueued);
 }
 
--- old/src/hotspot/share/gc/z/zStat.hpp	2018-03-05 15:14:50.873001792 +0100
+++ new/src/hotspot/share/gc/z/zStat.hpp	2018-03-05 15:14:50.701994465 +0100
@@ -414,18 +414,17 @@
   static struct ZCount {
     size_t encountered;
     size_t discovered;
-    size_t dropped;
     size_t enqueued;
   } _soft, _weak, _final, _phantom;
 
-  static void set(ZCount* count, size_t encountered, size_t dropped, size_t enqueued);
+  static void set(ZCount* count, size_t encountered, size_t discovered, size_t enqueued);
   static void print(const char* name, const ZCount& ref);
 
 public:
-  static void set_soft(size_t encountered, size_t dropped, size_t enqueued);
-  static void set_weak(size_t encountered, size_t dropped, size_t enqueued);
-  static void set_final(size_t encountered, size_t dropped, size_t enqueued);
-  static void set_phantom(size_t encountered, size_t dropped, size_t enqueued);
+  static void set_soft(size_t encountered, size_t discovered, size_t enqueued);
+  static void set_weak(size_t encountered, size_t discovered, size_t enqueued);
+  static void set_final(size_t encountered, size_t discovered, size_t enqueued);
+  static void set_phantom(size_t encountered, size_t discovered, size_t enqueued);
 
   static void print();
 };