src/share/vm/gc/g1/concurrentMarkThread.cpp

*** 139,151 ****
--- 139,153 ----
        // have been scanned. If we did then it's possible that a
        // subsequent GC could block us from joining the STS and proceed
        // without the root regions have been scanned which would be a
        // correctness issue.
  
+       if (_cm->root_regions()->scan_in_progress()) {
          assert(!cm()->has_aborted(), "Aborting before root region scanning is finished not supported.");
          GCConcPhaseTimer(_cm, "Concurrent Root Region Scanning");
          _cm->scanRootRegions();
+       }
  
        // It would be nice to use the GCTraceConcTime class here but
        // the "end" logging is inside the loop and not at the end of
        // a scope. Mimicking the same log output as GCTraceConcTime instead.
        jlong mark_start = os::elapsed_counter();