--- old/src/hotspot/share/gc/g1/g1ConcurrentMarkThread.cpp	2018-05-08 09:19:12.671834352 +0200
+++ new/src/hotspot/share/gc/g1/g1ConcurrentMarkThread.cpp	2018-05-08 09:19:12.382825438 +0200
@@ -311,10 +311,8 @@
           }
 
           if (G1UseReferencePrecleaning) {
-            {
-              G1ConcPhase p(G1ConcurrentPhase::PRECLEAN, this);
-              _cm->preclean();
-            }
+            G1ConcPhase p(G1ConcurrentPhase::PRECLEAN, this);
+            _cm->preclean();
           }
 
           // Provide a control point before remark.
--- old/src/hotspot/share/gc/shared/referenceProcessor.hpp	2018-05-08 09:19:13.899872231 +0200
+++ new/src/hotspot/share/gc/shared/referenceProcessor.hpp	2018-05-08 09:19:13.582862452 +0200
@@ -288,7 +288,6 @@
   // The caller is responsible for taking care of potential
   // interference with concurrent operations on these lists
   // (or predicates involved) by other threads.
-  // Returns whether the operation should be aborted.
   void preclean_discovered_references(BoolObjectClosure* is_alive,
                                       OopClosure*        keep_alive,
                                       VoidClosure*       complete_gc,
@@ -303,6 +302,7 @@
   // "Preclean" the given discovered reference list by removing references with
   // the attributes mentioned in preclean_discovered_references().
   // Supports both normal and fine grain yielding.
+  // Returns whether the operation should be aborted.
   bool preclean_discovered_reflist(DiscoveredList&    refs_list,
                                    BoolObjectClosure* is_alive,
                                    OopClosure*        keep_alive,