--- old/src/share/vm/gc_implementation/parNew/parNewGeneration.cpp	2013-03-11 17:49:01.000000000 +0100
+++ new/src/share/vm/gc_implementation/parNew/parNewGeneration.cpp	2013-03-11 17:49:01.000000000 +0100
@@ -891,12 +891,9 @@
   assert(full || size > 0, "otherwise we don't want to collect");
 
   GenCollectedHeap* gch = GenCollectedHeap::heap();
-
-  _gc_timer->register_gc_start(os::elapsed_counter());
   ParNewTracer gc_tracer;
-  gc_tracer.report_gc_start(gch->gc_cause(), _gc_timer->gc_start());
 
-  gch->trace_heap_before_gc(&gc_tracer);
+  _gc_timer->register_gc_start(os::elapsed_counter());
 
   assert(gch->kind() == CollectedHeap::GenCollectedHeap,
     "not a CMS generational heap");
@@ -927,6 +924,9 @@
   }
   assert(to()->is_empty(), "Else not collection_attempt_is_safe");
 
+  gc_tracer.report_gc_start(gch->gc_cause(), _gc_timer->gc_start());
+  gch->trace_heap_before_gc(&gc_tracer);
+
   init_assuming_no_promotion_failure();
 
   if (UseAdaptiveSizePolicy) {