--- a/hotspot/src/share/vm/gc/g1/dirtyCardQueue.cpp	Tue Jul 26 11:04:20 2016 +0200
+++ b/hotspot/src/share/vm/gc/g1/dirtyCardQueue.cpp	Tue Jul 26 11:04:20 2016 +0200
@@ -122,7 +122,7 @@
 
 // Determines how many mutator threads can process the buffers in parallel.
 uint DirtyCardQueueSet::num_par_ids() {
-  return (uint)os::processor_count();
+  return (uint)os::initial_active_processor_count();
 }
 
 void DirtyCardQueueSet::initialize(CardTableEntryClosure* cl,