diff -r 3a298e04d914 -r bca17e38de00 src/share/vm/gc_implementation/parallelScavenge/psCompactionManager.cpp
--- a/src/share/vm/gc_implementation/parallelScavenge/psCompactionManager.cpp	Tue Nov 22 04:47:10 2011 -0500
+++ b/src/share/vm/gc_implementation/parallelScavenge/psCompactionManager.cpp	Tue Aug 09 10:16:01 2011 -0700
@@ -39,6 +39,9 @@
 
 PSOldGen*            ParCompactionManager::_old_gen = NULL;
 ParCompactionManager**  ParCompactionManager::_manager_array = NULL;
+
+RegionTaskQueue**              ParCompactionManager::_region_list = NULL;
+
 OopTaskQueueSet*     ParCompactionManager::_stack_array = NULL;
 ParCompactionManager::ObjArrayTaskQueueSet*
   ParCompactionManager::_objarray_queues = NULL;
@@ -46,8 +49,14 @@
 ParMarkBitMap*       ParCompactionManager::_mark_bitmap = NULL;
 RegionTaskQueueSet*  ParCompactionManager::_region_array = NULL;
 
+uint*                 ParCompactionManager::_recycled_stack_index = NULL;
+int                   ParCompactionManager::_recycled_top = -1;
+int                   ParCompactionManager::_recycled_bottom = -1;
+
 ParCompactionManager::ParCompactionManager() :
-    _action(CopyAndUpdate) {
+    _action(CopyAndUpdate),
+    _region_stack(NULL),
+    _region_stack_index((uint)max_uintx) {
 
   ParallelScavengeHeap* heap = (ParallelScavengeHeap*)Universe::heap();
   assert(heap->kind() == CollectedHeap::ParallelScavengeHeap, "Sanity");
@@ -57,7 +66,10 @@
 
   marking_stack()->initialize();
   _objarray_stack.initialize();
-  region_stack()->initialize();
+}
+
+ParCompactionManager::~ParCompactionManager() {
+  delete _recycled_stack_index;
 }
 
 void ParCompactionManager::initialize(ParMarkBitMap* mbm) {
@@ -72,6 +84,19 @@
   _manager_array = NEW_C_HEAP_ARRAY(ParCompactionManager*, parallel_gc_threads+1 );
   guarantee(_manager_array != NULL, "Could not allocate manager_array");
 
+  _region_list = NEW_C_HEAP_ARRAY(RegionTaskQueue*,
+                                         parallel_gc_threads+1);
+  guarantee(_region_list != NULL, "Could not initialize promotion manager");
+
+  _recycled_stack_index = NEW_C_HEAP_ARRAY(uint, parallel_gc_threads);
+
+  // parallel_gc-threads + 1 to be consistent with the number of
+  // compaction managers.
+  for(uint i=0; i<parallel_gc_threads + 1; i++) {
+    _region_list[i] = new RegionTaskQueue();
+    region_list(i)->initialize();
+  }
+
   _stack_array = new OopTaskQueueSet(parallel_gc_threads);
   guarantee(_stack_array != NULL, "Could not allocate stack_array");
   _objarray_queues = new ObjArrayTaskQueueSet(parallel_gc_threads);
@@ -85,7 +110,7 @@
     guarantee(_manager_array[i] != NULL, "Could not create ParCompactionManager");
     stack_array()->register_queue(i, _manager_array[i]->marking_stack());
     _objarray_queues->register_queue(i, &_manager_array[i]->_objarray_stack);
-    region_array()->register_queue(i, _manager_array[i]->region_stack());
+    region_array()->register_queue(i, region_list(i));
   }
 
   // The VMThread gets its own ParCompactionManager, which is not available
@@ -97,6 +122,29 @@
     "Not initialized?");
 }
 
+int ParCompactionManager::pop_recycled_stack_index() {
+  assert(_recycled_bottom <= _recycled_top, "list is empty");
+  // Get the next available index
+  if (_recycled_bottom < _recycled_top) {
+    uint cur, next, last;
+    do {
+      cur = _recycled_bottom;
+      next = cur + 1;
+      last = Atomic::cmpxchg(next, &_recycled_bottom, cur);
+    } while (cur != last);
+    return _recycled_stack_index[next];
+  } else {
+    return -1;
+  }
+}
+
+void ParCompactionManager::push_recycled_stack_index(uint v) {
+  // Get the next available index
+  int cur = Atomic::add(1, &_recycled_top);
+  _recycled_stack_index[cur] = v;
+  assert(_recycled_bottom <= _recycled_top, "list top and bottom are wrong");
+}
+
 bool ParCompactionManager::should_update() {
   assert(action() != NotValid, "Action is not set");
   return (action() == ParCompactionManager::Update) ||
@@ -121,6 +169,15 @@
   return action() == ParCompactionManager::ResetObjects;
 }
 
+void ParCompactionManager::region_list_push(uint list_index,
+                                            size_t region_index) {
+  region_list(list_index)->push(region_index);
+}
+
+void ParCompactionManager::verify_region_list_empty(uint list_index) {
+  assert(region_list(list_index)->is_empty(), "Not empty");
+}
+
 ParCompactionManager*
 ParCompactionManager::gc_thread_compaction_manager(int index) {
   assert(index >= 0 && index < (int)ParallelGCThreads, "index out of range");