8005849: JEP 167: Event-Based JVM Tracing Reviewed-by: acorn, coleenp, sla Contributed-by: Karen Kinnear <karen.kinnear@oracle.com>, Bengt Rutisson <bengt.rutisson@oracle.com>, Calvin Cheung <calvin.cheung@oracle.com>, Erik Gahlin <erik.gahlin@oracle.com>, Erik Helin <erik.helin@oracle.com>, Jesper Wilhelmsson <jesper.wilhelmsson@oracle.com>, Keith McGuigan <keith.mcguigan@oracle.com>, Mattias Tobiasson <mattias.tobiasson@oracle.com>, Markus Gronlund <markus.gronlund@oracle.com>, Mikael Auno <mikael.auno@oracle.com>, Nils Eliasson <nils.eliasson@oracle.com>, Nils Loodin <nils.loodin@oracle.com>, Rickard Backman <rickard.backman@oracle.com>, Staffan Larsen <staffan.larsen@oracle.com>, Stefan Karlsson <stefan.karlsson@oracle.com>, Yekaterina Kantserova <yekaterina.kantserova@oracle.com>

--- a/src/share/vm/gc_implementation/concurrentMarkSweep/concurrentMarkSweepThread.cpp	Fri Jun 07 09:33:01 2013 -0700
+++ b/src/share/vm/gc_implementation/concurrentMarkSweep/concurrentMarkSweepThread.cpp	Mon Jun 10 11:30:51 2013 +0200
@@ -140,7 +140,9 @@
   while (!_should_terminate) {
     sleepBeforeNextCycle();
     if (_should_terminate) break;
-    _collector->collect_in_background(false);  // !clear_all_soft_refs
+    GCCause::Cause cause = _collector->_full_gc_requested ?
+      _collector->_full_gc_cause : GCCause::_cms_concurrent_mark;
+    _collector->collect_in_background(false, cause);
   }
   assert(_should_terminate, "just checking");
   // Check that the state of any protocol for synchronization