--- old/src/share/vm/gc_implementation/concurrentMarkSweep/concurrentMarkSweepGeneration.cpp	2014-11-14 08:01:06.982339385 +0100
+++ new/src/share/vm/gc_implementation/concurrentMarkSweep/concurrentMarkSweepGeneration.cpp	2014-11-14 08:01:06.898339388 +0100
@@ -192,7 +192,6 @@
      FreeBlockDictionary<FreeChunk>::DictionaryChoice dictionaryChoice) :
   CardGeneration(rs, initial_byte_size, level, ct),
   _dilatation_factor(((double)MinChunkSize)/((double)(CollectedHeap::min_fill_size()))),
-  _debug_concurrent_cycle(true),
   _did_compact(false)
 {
   HeapWord* bottom = (HeapWord*) _virtual_space.low();
@@ -1245,14 +1244,6 @@
     return true;
   }
 
-  // For debugging purposes, change the type of collection.
-  // Rotate between concurrent and stop-the-world full GCs.
-  NOT_PRODUCT(
-    if (RotateCMSCollectionTypes) {
-      return _cmsGen->debug_concurrent_cycle();
-    }
-  )
-
   FreelistLocker x(this);
   // ------------------------------------------------------------------
   // Print out lots of information which affects the initiation of
@@ -5822,17 +5813,6 @@
   }
 }
 
-void ConcurrentMarkSweepGeneration::rotate_debug_collection_type() {
-  if (PrintGCDetails && Verbose) {
-    if (_debug_concurrent_cycle) {
-      gclog_or_tty->print_cr("Rotate from concurrent to STW collections");
-    } else {
-      gclog_or_tty->print_cr("Rotate from STW to concurrent collections");
-    }
-  }
-  _debug_concurrent_cycle = !_debug_concurrent_cycle;
-}
-
 void CMSCollector::sweepWork(ConcurrentMarkSweepGeneration* gen) {
   // We iterate over the space(s) underlying this generation,
   // checking the mark bit map to see if the bits corresponding
@@ -5953,12 +5933,6 @@
     _collectorState = Idling;
   }
 
-  NOT_PRODUCT(
-    if (RotateCMSCollectionTypes) {
-      _cmsGen->rotate_debug_collection_type();
-    }
-  )
-
   register_gc_end();
 }