src/hotspot/share/gc/g1/g1ConcurrentMarkThread.cpp

rev 49953 : imported patch 8201491-precleaning
rev 49954 : [mq]: 8201491-kbarrett-review

*** 55,64 ****
--- 55,65 ----
    expander(CONCURRENT_CYCLE,, "Concurrent Cycle")                          \
    expander(CLEAR_CLAIMED_MARKS,, "Concurrent Clear Claimed Marks")         \
    expander(SCAN_ROOT_REGIONS,, "Concurrent Scan Root Regions")             \
    expander(CONCURRENT_MARK,, "Concurrent Mark")                            \
    expander(MARK_FROM_ROOTS,, "Concurrent Mark From Roots")                 \
+   expander(PRECLEAN,, "Concurrent Preclean")                               \
    expander(BEFORE_REMARK,, NULL)                                           \
    expander(REMARK,, NULL)                                                  \
    expander(REBUILD_REMEMBERED_SETS,, "Concurrent Rebuild Remembered Sets") \
    expander(CLEANUP_FOR_NEXT_MARK,, "Concurrent Cleanup for Next Mark")     \
    /* */
*** 307,317 ****
            }
            if (_cm->has_aborted()) {
              break;
            }
  
!           // Provide a control point after mark_from_roots.
            {
              G1ConcPhaseManager p(G1ConcurrentPhase::BEFORE_REMARK, this);
            }
            if (_cm->has_aborted()) {
              break;
--- 308,323 ----
            }
            if (_cm->has_aborted()) {
              break;
            }
  
!           if (G1UseReferencePrecleaning) {
!             G1ConcPhase p(G1ConcurrentPhase::PRECLEAN, this);
!             _cm->preclean();
!           }
! 
!           // Provide a control point before remark.
            {
              G1ConcPhaseManager p(G1ConcurrentPhase::BEFORE_REMARK, this);
            }
            if (_cm->has_aborted()) {
              break;