6814467: G1: small fixes related to concurrent marking verboseness

Summary: A few small fixes to remove some inconsistencies in the concurrent mark-related verbose GC output.
Reviewed-by: jmasa

src/share/vm/gc_implementation/g1/concurrentMark.cpp

@@ -420,6 +420,10 @@ ConcurrentMark::ConcurrentMark(ReservedSpace rs,
 
   _has_overflown(false),
   _concurrent(false),
+  _has_aborted(false),
+  _restart_for_overflow(false),
+  _concurrent_marking_in_progress(false),
+  _should_gray_objects(false),
 
   // _verbose_level set below
 

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

@@ -107,7 +107,7 @@ void ConcurrentMarkThread::run() {
       if (PrintGC) {
         gclog_or_tty->date_stamp(PrintGCDateStamps);
         gclog_or_tty->stamp(PrintGCTimeStamps);
-        tty->print_cr("[GC concurrent-mark-start]");
+        gclog_or_tty->print_cr("[GC concurrent-mark-start]");
       }
 
       if (!g1_policy->in_young_gc_mode()) {
@@ -320,8 +320,6 @@ void ConcurrentMarkThread::sleepBeforeNextCycle() {
   set_in_progress();
   clear_started();
   if (TraceConcurrentMark) gclog_or_tty->print_cr("CM-starting");
-
-  return;
 }
 
 // Note: this method, although exported by the ConcurrentMarkSweepThread,

src/share/vm/gc_implementation/g1/g1CollectedHeap.cpp

@@ -2332,7 +2332,6 @@ class VerifyMarkedObjsClosure: public ObjectClosure {
 void
 G1CollectedHeap::checkConcurrentMark() {
     VerifyMarkedObjsClosure verifycl(this);
-    doConcurrentMark();
     //    MutexLockerEx x(getMarkBitMapLock(),
     //              Mutex::_no_safepoint_check_flag);
     object_iterate(&verifycl);