diff --git a/src/share/vm/gc_implementation/g1/collectionSetChooser.cpp b/src/share/vm/gc_implementation/g1/collectionSetChooser.cpp
index 29a03275c61145441933890e3d3dd5deb3c07a49..663011a77b1de24ad9fc1760d9fa76653a1ca0df 100644
--- a/src/share/vm/gc_implementation/g1/collectionSetChooser.cpp
+++ b/src/share/vm/gc_implementation/g1/collectionSetChooser.cpp
@@ -29,102 +29,6 @@
 #include "gc_implementation/g1/g1ErgoVerbose.hpp"
 #include "memory/space.inline.hpp"
 
-CSetChooserCache::CSetChooserCache() {
-  for (int i = 0; i < CacheLength; ++i)
-    _cache[i] = NULL;
-  clear();
-}
-
-void CSetChooserCache::clear() {
-  _occupancy = 0;
-  _first = 0;
-  for (int i = 0; i < CacheLength; ++i) {
-    HeapRegion *hr = _cache[i];
-    if (hr != NULL)
-      hr->set_sort_index(-1);
-    _cache[i] = NULL;
-  }
-}
-
-#ifndef PRODUCT
-bool CSetChooserCache::verify() {
-  guarantee(false, "CSetChooserCache::verify(): don't call this any more");
-
-  int index = _first;
-  HeapRegion *prev = NULL;
-  for (int i = 0; i < _occupancy; ++i) {
-    guarantee(_cache[index] != NULL, "cache entry should not be empty");
-    HeapRegion *hr = _cache[index];
-    guarantee(!hr->is_young(), "should not be young!");
-    if (prev != NULL) {
-      guarantee(prev->gc_efficiency() >= hr->gc_efficiency(),
-                "cache should be correctly ordered");
-    }
-    guarantee(hr->sort_index() == get_sort_index(index),
-              "sort index should be correct");
-    index = trim_index(index + 1);
-    prev = hr;
-  }
-
-  for (int i = 0; i < (CacheLength - _occupancy); ++i) {
-    guarantee(_cache[index] == NULL, "cache entry should be empty");
-    index = trim_index(index + 1);
-  }
-
-  guarantee(index == _first, "we should have reached where we started from");
-  return true;
-}
-#endif // PRODUCT
-
-void CSetChooserCache::insert(HeapRegion *hr) {
-  guarantee(false, "CSetChooserCache::insert(): don't call this any more");
-
-  assert(!is_full(), "cache should not be empty");
-  hr->calc_gc_efficiency();
-
-  int empty_index;
-  if (_occupancy == 0) {
-    empty_index = _first;
-  } else {
-    empty_index = trim_index(_first + _occupancy);
-    assert(_cache[empty_index] == NULL, "last slot should be empty");
-    int last_index = trim_index(empty_index - 1);
-    HeapRegion *last = _cache[last_index];
-    assert(last != NULL,"as the cache is not empty, last should not be empty");
-    while (empty_index != _first &&
-           last->gc_efficiency() < hr->gc_efficiency()) {
-      _cache[empty_index] = last;
-      last->set_sort_index(get_sort_index(empty_index));
-      empty_index = last_index;
-      last_index = trim_index(last_index - 1);
-      last = _cache[last_index];
-    }
-  }
-  _cache[empty_index] = hr;
-  hr->set_sort_index(get_sort_index(empty_index));
-
-  ++_occupancy;
-  assert(verify(), "cache should be consistent");
-}
-
-HeapRegion *CSetChooserCache::remove_first() {
-  guarantee(false, "CSetChooserCache::remove_first(): "
-                   "don't call this any more");
-
-  if (_occupancy > 0) {
-    assert(_cache[_first] != NULL, "cache should have at least one region");
-    HeapRegion *ret = _cache[_first];
-    _cache[_first] = NULL;
-    ret->set_sort_index(-1);
-    --_occupancy;
-    _first = trim_index(_first + 1);
-    assert(verify(), "cache should be consistent");
-    return ret;
-  } else {
-    return NULL;
-  }
-}
-
 // Even though we don't use the GC efficiency in our heuristics as
 // much as we used to, we still order according to GC efficiency. This
 // will cause regions with a lot of live objects and large RSets to
@@ -134,7 +38,7 @@ HeapRegion *CSetChooserCache::remove_first() {
 // the ones we'll skip are ones with both large RSets and a lot of
 // live objects, not the ones with just a lot of live objects if we
 // ordered according to the amount of reclaimable bytes per region.
-static int orderRegions(HeapRegion* hr1, HeapRegion* hr2) {
+static int order_regions(HeapRegion* hr1, HeapRegion* hr2) {
   if (hr1 == NULL) {
     if (hr2 == NULL) {
       return 0;
@@ -156,8 +60,8 @@ static int orderRegions(HeapRegion* hr1, HeapRegion* hr2) {
   }
 }
 
-static int orderRegions(HeapRegion** hr1p, HeapRegion** hr2p) {
-  return orderRegions(*hr1p, *hr2p);
+static int order_regions(HeapRegion** hr1p, HeapRegion** hr2p) {
+  return order_regions(*hr1p, *hr2p);
 }
 
 CollectionSetChooser::CollectionSetChooser() :
@@ -175,105 +79,74 @@ CollectionSetChooser::CollectionSetChooser() :
   //
   // Note: containing object is allocated on C heap since it is CHeapObj.
   //
-  _markedRegions((ResourceObj::set_allocation_type((address)&_markedRegions,
+  _regions((ResourceObj::set_allocation_type((address) &_regions,
                                              ResourceObj::C_HEAP),
                   100), true /* C_Heap */),
-    _curr_index(0), _length(0),
-    _regionLiveThresholdBytes(0), _remainingReclaimableBytes(0),
-    _first_par_unreserved_idx(0) {
-  _regionLiveThresholdBytes =
+    _curr_index(0), _length(0), _first_par_unreserved_idx(0),
+    _region_live_threshold_bytes(0), _remaining_reclaimable_bytes(0) {
+  _region_live_threshold_bytes =
     HeapRegion::GrainBytes * (size_t) G1OldCSetRegionLiveThresholdPercent / 100;
 }
 
 #ifndef PRODUCT
-bool CollectionSetChooser::verify() {
-  guarantee(_length >= 0, err_msg("_length: %d", _length));
-  guarantee(0 <= _curr_index && _curr_index <= _length,
-            err_msg("_curr_index: %d _length: %d", _curr_index, _length));
-  int index = 0;
+void CollectionSetChooser::verify() {
+  guarantee(_length <= regions_length(),
+         err_msg("_length: %u regions length: %u", _length, regions_length()));
+  guarantee(_curr_index <= _length,
+            err_msg("_curr_index: %u _length: %u", _curr_index, _length));
+  uint index = 0;
   size_t sum_of_reclaimable_bytes = 0;
   while (index < _curr_index) {
-    guarantee(_markedRegions.at(index) == NULL,
+    guarantee(regions_at(index) == NULL,
               "all entries before _curr_index should be NULL");
     index += 1;
   }
   HeapRegion *prev = NULL;
   while (index < _length) {
-    HeapRegion *curr = _markedRegions.at(index++);
-    guarantee(curr != NULL, "Regions in _markedRegions array cannot be NULL");
-    int si = curr->sort_index();
+    HeapRegion *curr = regions_at(index++);
+    guarantee(curr != NULL, "Regions in _regions array cannot be NULL");
     guarantee(!curr->is_young(), "should not be young!");
     guarantee(!curr->isHumongous(), "should not be humongous!");
-    guarantee(si > -1 && si == (index-1), "sort index invariant");
     if (prev != NULL) {
-      guarantee(orderRegions(prev, curr) != 1,
+      guarantee(order_regions(prev, curr) != 1,
                 err_msg("GC eff prev: %1.4f GC eff curr: %1.4f",
                         prev->gc_efficiency(), curr->gc_efficiency()));
     }
     sum_of_reclaimable_bytes += curr->reclaimable_bytes();
     prev = curr;
   }
-  guarantee(sum_of_reclaimable_bytes == _remainingReclaimableBytes,
+  guarantee(sum_of_reclaimable_bytes == _remaining_reclaimable_bytes,
             err_msg("reclaimable bytes inconsistent, "
                     "remaining: "SIZE_FORMAT" sum: "SIZE_FORMAT,
-                    _remainingReclaimableBytes, sum_of_reclaimable_bytes));
-  return true;
-}
-#endif
-
-void CollectionSetChooser::fillCache() {
-  guarantee(false, "fillCache: don't call this any more");
-
-  while (!_cache.is_full() && (_curr_index < _length)) {
-    HeapRegion* hr = _markedRegions.at(_curr_index);
-    assert(hr != NULL,
-           err_msg("Unexpected NULL hr in _markedRegions at index %d",
-                   _curr_index));
-    _curr_index += 1;
-    assert(!hr->is_young(), "should not be young!");
-    assert(hr->sort_index() == _curr_index-1, "sort_index invariant");
-    _markedRegions.at_put(hr->sort_index(), NULL);
-    _cache.insert(hr);
-    assert(!_cache.is_empty(), "cache should not be empty");
-  }
-  assert(verify(), "cache should be consistent");
+                    _remaining_reclaimable_bytes, sum_of_reclaimable_bytes));
 }
+#endif // !PRODUCT
 
-void CollectionSetChooser::sortMarkedHeapRegions() {
+void CollectionSetChooser::sort_regions() {
   // First trim any unused portion of the top in the parallel case.
   if (_first_par_unreserved_idx > 0) {
-    if (G1PrintParCleanupStats) {
-      gclog_or_tty->print("     Truncating _markedRegions from %d to %d.\n",
-                          _markedRegions.length(), _first_par_unreserved_idx);
-    }
-    assert(_first_par_unreserved_idx <= _markedRegions.length(),
+    assert(_first_par_unreserved_idx <= regions_length(),
            "Or we didn't reserved enough length");
-    _markedRegions.trunc_to(_first_par_unreserved_idx);
-  }
-  _markedRegions.sort(orderRegions);
-  assert(_length <= _markedRegions.length(), "Requirement");
-  assert(_length == 0 || _markedRegions.at(_length - 1) != NULL,
-         "Testing _length");
-  assert(_length == _markedRegions.length() ||
-                        _markedRegions.at(_length) == NULL, "Testing _length");
-  if (G1PrintParCleanupStats) {
-    gclog_or_tty->print_cr("     Sorted %d marked regions.", _length);
+    regions_trunc_to(_first_par_unreserved_idx);
   }
-  for (int i = 0; i < _length; i++) {
-    assert(_markedRegions.at(i) != NULL, "Should be true by sorting!");
-    _markedRegions.at(i)->set_sort_index(i);
+  _regions.sort(order_regions);
+  assert(_length <= regions_length(), "Requirement");
+#ifdef ASSERT
+  for (uint i = 0; i < _length; i++) {
+    assert(regions_at(i) != NULL, "Should be true by sorting!");
   }
+#endif // ASSERT
   if (G1PrintRegionLivenessInfo) {
     G1PrintRegionLivenessInfoClosure cl(gclog_or_tty, "Post-Sorting");
-    for (int i = 0; i < _length; ++i) {
-      HeapRegion* r = _markedRegions.at(i);
+    for (uint i = 0; i < _length; ++i) {
+      HeapRegion* r = regions_at(i);
       cl.doHeapRegion(r);
     }
   }
-  assert(verify(), "CSet chooser verification");
+  verify();
 }
 
-uint CollectionSetChooser::calcMinOldCSetLength() {
+uint CollectionSetChooser::calc_min_old_cset_length() {
   // The min old CSet region bound is based on the maximum desired
   // number of mixed GCs after a cycle. I.e., even if some old regions
   // look expensive, we should add them to the CSet anyway to make
@@ -294,7 +167,7 @@ uint CollectionSetChooser::calcMinOldCSetLength() {
   return (uint) result;
 }
 
-uint CollectionSetChooser::calcMaxOldCSetLength() {
+uint CollectionSetChooser::calc_max_old_cset_length() {
   // The max old CSet region bound is based on the threshold expressed
   // as a percentage of the heap size. I.e., it should bound the
   // number of old regions added to the CSet irrespective of how many
@@ -311,18 +184,18 @@ uint CollectionSetChooser::calcMaxOldCSetLength() {
   return (uint) result;
 }
 
-void CollectionSetChooser::addMarkedHeapRegion(HeapRegion* hr) {
+void CollectionSetChooser::add_region(HeapRegion* hr) {
   assert(!hr->isHumongous(),
          "Humongous regions shouldn't be added to the collection set");
   assert(!hr->is_young(), "should not be young!");
-  _markedRegions.append(hr);
+  _regions.append(hr);
   _length++;
-  _remainingReclaimableBytes += hr->reclaimable_bytes();
+  _remaining_reclaimable_bytes += hr->reclaimable_bytes();
   hr->calc_gc_efficiency();
 }
 
-void CollectionSetChooser::prepareForAddMarkedHeapRegionsPar(uint n_regions,
-                                                             uint chunkSize) {
+void CollectionSetChooser::prepare_for_par_region_addition(uint n_regions,
+                                                           uint chunk_size) {
   _first_par_unreserved_idx = 0;
   uint n_threads = (uint) ParallelGCThreads;
   if (UseDynamicNumberOfGCThreads) {
@@ -335,56 +208,46 @@ void CollectionSetChooser::prepareForAddMarkedHeapRegionsPar(uint n_regions,
     n_threads = MAX2(G1CollectedHeap::heap()->workers()->active_workers(),
                      1U);
   }
-  uint max_waste = n_threads * chunkSize;
-  // it should be aligned with respect to chunkSize
-  uint aligned_n_regions = (n_regions + chunkSize - 1) / chunkSize * chunkSize;
-  assert(aligned_n_regions % chunkSize == 0, "should be aligned");
-  _markedRegions.at_put_grow((int) (aligned_n_regions + max_waste - 1), NULL);
+  uint max_waste = n_threads * chunk_size;
+  // it should be aligned with respect to chunk_size
+  uint aligned_n_regions = (n_regions + chunk_size - 1) / chunk_size * chunk_size;
+  assert(aligned_n_regions % chunk_size == 0, "should be aligned");
+  regions_at_put_grow(aligned_n_regions + max_waste - 1, NULL);
 }
 
-jint CollectionSetChooser::getParMarkedHeapRegionChunk(jint n_regions) {
-  // Don't do this assert because this can be called at a point
-  // where the loop up stream will not execute again but might
-  // try to claim more chunks (loop test has not been done yet).
-  // assert(_markedRegions.length() > _first_par_unreserved_idx,
-  //  "Striding beyond the marked regions");
-  jint res = Atomic::add(n_regions, &_first_par_unreserved_idx);
-  assert(_markedRegions.length() > res + n_regions - 1,
+uint CollectionSetChooser::claim_array_chunk(uint chunk_size) {
+  uint res = (uint) Atomic::add((jint) chunk_size,
+                                (volatile jint*) &_first_par_unreserved_idx);
+  assert(regions_length() > res + chunk_size - 1,
          "Should already have been expanded");
-  return res - n_regions;
+  return res - chunk_size;
 }
 
-void CollectionSetChooser::setMarkedHeapRegion(jint index, HeapRegion* hr) {
-  assert(_markedRegions.at(index) == NULL, "precondition");
+void CollectionSetChooser::set_region(uint index, HeapRegion* hr) {
+  assert(regions_at(index) == NULL, "precondition");
   assert(!hr->is_young(), "should not be young!");
-  _markedRegions.at_put(index, hr);
+  regions_at_put(index, hr);
   hr->calc_gc_efficiency();
 }
 
-void CollectionSetChooser::updateTotals(jint region_num,
-                                        size_t reclaimable_bytes) {
+void CollectionSetChooser::update_totals(uint region_num,
+                                         size_t reclaimable_bytes) {
   // Only take the lock if we actually need to update the totals.
   if (region_num > 0) {
     assert(reclaimable_bytes > 0, "invariant");
     // We could have just used atomics instead of taking the
     // lock. However, we currently don't have an atomic add for size_t.
     MutexLockerEx x(ParGCRareEvent_lock, Mutex::_no_safepoint_check_flag);
-    _length += (int) region_num;
-    _remainingReclaimableBytes += reclaimable_bytes;
+    _length += region_num;
+    _remaining_reclaimable_bytes += reclaimable_bytes;
   } else {
     assert(reclaimable_bytes == 0, "invariant");
   }
 }
 
-void CollectionSetChooser::clearMarkedHeapRegions() {
-  for (int i = 0; i < _markedRegions.length(); i++) {
-    HeapRegion* r = _markedRegions.at(i);
-    if (r != NULL) {
-      r->set_sort_index(-1);
-    }
-  }
-  _markedRegions.clear();
+void CollectionSetChooser::clear() {
+  _regions.clear();
   _curr_index = 0;
   _length = 0;
-  _remainingReclaimableBytes = 0;
+  _remaining_reclaimable_bytes = 0;
 };
diff --git a/src/share/vm/gc_implementation/g1/collectionSetChooser.hpp b/src/share/vm/gc_implementation/g1/collectionSetChooser.hpp
index caf18206066c58417cb2a5c5c8345aa7b3565cf8..e52476586c5a5ec3bee7d7b171b60dd4f48d692f 100644
--- a/src/share/vm/gc_implementation/g1/collectionSetChooser.hpp
+++ b/src/share/vm/gc_implementation/g1/collectionSetChooser.hpp
@@ -28,77 +28,42 @@
 #include "gc_implementation/g1/heapRegion.hpp"
 #include "utilities/growableArray.hpp"
 
-class CSetChooserCache VALUE_OBJ_CLASS_SPEC {
-private:
-  enum {
-    CacheLength = 16
-  } PrivateConstants;
-
-  HeapRegion*  _cache[CacheLength];
-  int          _occupancy; // number of regions in cache
-  int          _first;     // (index of) "first" region in the cache
-
-  // adding CacheLength to deal with negative values
-  inline int trim_index(int index) {
-    return (index + CacheLength) % CacheLength;
-  }
-
-  inline int get_sort_index(int index) {
-    return -index-2;
-  }
-  inline int get_index(int sort_index) {
-    return -sort_index-2;
-  }
+class CollectionSetChooser: public CHeapObj {
 
-public:
-  CSetChooserCache(void);
+  GrowableArray<HeapRegion*> _regions;
 
-  inline int occupancy(void) { return _occupancy; }
-  inline bool is_full()      { return _occupancy == CacheLength; }
-  inline bool is_empty()     { return _occupancy == 0; }
+  // Unfortunately, GrowableArray uses ints for length and indexes. To
+  // avoid excessive casting in the rest of the class the following
+  // wrapper methods are provided that use uints.
 
-  void clear(void);
-  void insert(HeapRegion *hr);
-  HeapRegion *remove_first(void);
-  inline HeapRegion *get_first(void) {
-    return _cache[_first];
+  uint regions_length()          { return (uint) _regions.length(); }
+  HeapRegion* regions_at(uint i) { return _regions.at((int) i);     }
+  void regions_at_put(uint i, HeapRegion* hr) {
+    _regions.at_put((int) i, hr);
   }
-
-#ifndef PRODUCT
-  bool verify (void);
-  bool region_in_cache(HeapRegion *hr) {
-    int sort_index = hr->sort_index();
-    if (sort_index < -1) {
-      int index = get_index(sort_index);
-      guarantee(index < CacheLength, "should be within bounds");
-      return _cache[index] == hr;
-    } else
-      return 0;
+  void regions_at_put_grow(uint i, HeapRegion* hr) {
+    _regions.at_put_grow((int) i, hr);
   }
-#endif // PRODUCT
-};
-
-class CollectionSetChooser: public CHeapObj {
-
-  GrowableArray<HeapRegion*> _markedRegions;
+  void regions_trunc_to(uint i)  { _regions.trunc_to((uint) i); }
 
   // The index of the next candidate old region to be considered for
   // addition to the CSet.
-  int _curr_index;
+  uint _curr_index;
 
   // The number of candidate old regions added to the CSet chooser.
-  int _length;
+  uint _length;
 
-  CSetChooserCache _cache;
-  jint _first_par_unreserved_idx;
+  // Keeps track of the start of the next array chunk to be claimed by
+  // parallel GC workers.
+  uint _first_par_unreserved_idx;
 
   // If a region has more live bytes than this threshold, it will not
   // be added to the CSet chooser and will not be a candidate for
   // collection.
-  size_t _regionLiveThresholdBytes;
+  size_t _region_live_threshold_bytes;
 
   // The sum of reclaimable bytes over all the regions in the CSet chooser.
-  size_t _remainingReclaimableBytes;
+  size_t _remaining_reclaimable_bytes;
 
 public:
 
@@ -107,9 +72,9 @@ public:
   HeapRegion* peek() {
     HeapRegion* res = NULL;
     if (_curr_index < _length) {
-      res = _markedRegions.at(_curr_index);
+      res = regions_at(_curr_index);
       assert(res != NULL,
-             err_msg("Unexpected NULL hr in _markedRegions at index %d",
+             err_msg("Unexpected NULL hr in _regions at index %u",
                      _curr_index));
     }
     return res;
@@ -121,90 +86,71 @@ public:
   void remove_and_move_to_next(HeapRegion* hr) {
     assert(hr != NULL, "pre-condition");
     assert(_curr_index < _length, "pre-condition");
-    assert(_markedRegions.at(_curr_index) == hr, "pre-condition");
-    hr->set_sort_index(-1);
-    _markedRegions.at_put(_curr_index, NULL);
-    assert(hr->reclaimable_bytes() <= _remainingReclaimableBytes,
+    assert(regions_at(_curr_index) == hr, "pre-condition");
+    regions_at_put(_curr_index, NULL);
+    assert(hr->reclaimable_bytes() <= _remaining_reclaimable_bytes,
            err_msg("remaining reclaimable bytes inconsistent "
                    "from region: "SIZE_FORMAT" remaining: "SIZE_FORMAT,
-                   hr->reclaimable_bytes(), _remainingReclaimableBytes));
-    _remainingReclaimableBytes -= hr->reclaimable_bytes();
+                   hr->reclaimable_bytes(), _remaining_reclaimable_bytes));
+    _remaining_reclaimable_bytes -= hr->reclaimable_bytes();
     _curr_index += 1;
   }
 
   CollectionSetChooser();
 
-  void sortMarkedHeapRegions();
-  void fillCache();
+  void sort_regions();
 
   // Determine whether to add the given region to the CSet chooser or
   // not. Currently, we skip humongous regions (we never add them to
   // the CSet, we only reclaim them during cleanup) and regions whose
   // live bytes are over the threshold.
-  bool shouldAdd(HeapRegion* hr) {
+  bool should_add(HeapRegion* hr) {
     assert(hr->is_marked(), "pre-condition");
     assert(!hr->is_young(), "should never consider young regions");
     return !hr->isHumongous() &&
-            hr->live_bytes() < _regionLiveThresholdBytes;
+            hr->live_bytes() < _region_live_threshold_bytes;
   }
 
   // Calculate the minimum number of old regions we'll add to the CSet
   // during a mixed GC.
-  uint calcMinOldCSetLength();
+  uint calc_min_old_cset_length();
 
   // Calculate the maximum number of old regions we'll add to the CSet
   // during a mixed GC.
-  uint calcMaxOldCSetLength();
+  uint calc_max_old_cset_length();
 
   // Serial version.
-  void addMarkedHeapRegion(HeapRegion *hr);
+  void add_region(HeapRegion *hr);
 
-  // Must be called before calls to getParMarkedHeapRegionChunk.
-  // "n_regions" is the number of regions, "chunkSize" the chunk size.
-  void prepareForAddMarkedHeapRegionsPar(uint n_regions, uint chunkSize);
-  // Returns the first index in a contiguous chunk of "n_regions" indexes
+  // Must be called before calls to claim_array_chunk().
+  // n_regions is the number of regions, chunk_size the chunk size.
+  void prepare_for_par_region_addition(uint n_regions, uint chunk_size);
+  // Returns the first index in a contiguous chunk of chunk_size indexes
   // that the calling thread has reserved.  These must be set by the
-  // calling thread using "setMarkedHeapRegion" (to NULL if necessary).
-  jint getParMarkedHeapRegionChunk(jint n_regions);
+  // calling thread using set_region() (to NULL if necessary).
+  uint claim_array_chunk(uint chunk_size);
   // Set the marked array entry at index to hr.  Careful to claim the index
   // first if in parallel.
-  void setMarkedHeapRegion(jint index, HeapRegion* hr);
+  void set_region(uint index, HeapRegion* hr);
   // Atomically increment the number of added regions by region_num
   // and the amount of reclaimable bytes by reclaimable_bytes.
-  void updateTotals(jint region_num, size_t reclaimable_bytes);
+  void update_totals(uint region_num, size_t reclaimable_bytes);
 
-  void clearMarkedHeapRegions();
+  void clear();
 
   // Return the number of candidate regions that remain to be collected.
-  uint remainingRegions() { return (uint) (_length - _curr_index); }
+  uint remaining_regions() { return _length - _curr_index; }
 
   // Determine whether the CSet chooser has more candidate regions or not.
-  bool isEmpty() { return remainingRegions() == 0; }
+  bool is_empty() { return remaining_regions() == 0; }
 
   // Return the reclaimable bytes that remain to be collected on
   // all the candidate regions in the CSet chooser.
-  size_t remainingReclaimableBytes () { return _remainingReclaimableBytes; }
+  size_t remaining_reclaimable_bytes() { return _remaining_reclaimable_bytes; }
 
-  // Returns true if the used portion of "_markedRegions" is properly
+  // Returns true if the used portion of "_regions" is properly
   // sorted, otherwise asserts false.
-#ifndef PRODUCT
-  bool verify(void);
-  bool regionProperlyOrdered(HeapRegion* r) {
-    int si = r->sort_index();
-    if (si > -1) {
-      guarantee(_curr_index <= si && si < _length,
-                err_msg("curr: %d sort index: %d: length: %d",
-                        _curr_index, si, _length));
-      guarantee(_markedRegions.at(si) == r,
-                err_msg("sort index: %d at: "PTR_FORMAT" r: "PTR_FORMAT,
-                        si, _markedRegions.at(si), r));
-    } else {
-      guarantee(si == -1, err_msg("sort index: %d", si));
-    }
-    return true;
-  }
-#endif
-
+  void verify() PRODUCT_RETURN;
 };
 
 #endif // SHARE_VM_GC_IMPLEMENTATION_G1_COLLECTIONSETCHOOSER_HPP
diff --git a/src/share/vm/gc_implementation/g1/concurrentMark.cpp b/src/share/vm/gc_implementation/g1/concurrentMark.cpp
index 15eb1b6ea5623452e1c1f94ccf8a6f46db2ebbb2..ba29b3120db7b9d797809cc681f721fa86c8c600 100644
--- a/src/share/vm/gc_implementation/g1/concurrentMark.cpp
+++ b/src/share/vm/gc_implementation/g1/concurrentMark.cpp
@@ -1192,11 +1192,6 @@ class CalcLiveObjectsClosure: public HeapRegionClosure {
   BitMap* _region_bm;
   BitMap* _card_bm;
 
-  // Debugging
-  size_t _tot_words_done;
-  size_t _tot_live;
-  size_t _tot_used;
-
   size_t _region_marked_bytes;
 
   intptr_t _bottom_card_num;
@@ -1215,9 +1210,7 @@ public:
   CalcLiveObjectsClosure(CMBitMapRO *bm, ConcurrentMark *cm,
                          BitMap* region_bm, BitMap* card_bm) :
     _bm(bm), _cm(cm), _region_bm(region_bm), _card_bm(card_bm),
-    _region_marked_bytes(0), _tot_words_done(0),
-    _tot_live(0), _tot_used(0),
-    _bottom_card_num(cm->heap_bottom_card_num()) { }
+    _region_marked_bytes(0), _bottom_card_num(cm->heap_bottom_card_num()) { }
 
   // It takes a region that's not empty (i.e., it has at least one
   // live object in it and sets its corresponding bit on the region
@@ -1262,9 +1255,6 @@ public:
                    "start: "PTR_FORMAT", nextTop: "PTR_FORMAT", end: "PTR_FORMAT,
                    start, nextTop, hr->end()));
 
-    // Record the number of word's we'll examine.
-    size_t words_done = (nextTop - start);
-
     // Find the first marked object at or after "start".
     start = _bm->getNextMarkedWordAddress(start, nextTop);
 
@@ -1343,19 +1333,10 @@ public:
     // it can be queried by a calling verificiation routine
     _region_marked_bytes = marked_bytes;
 
-    _tot_live += hr->next_live_bytes();
-    _tot_used += hr->used();
-    _tot_words_done = words_done;
-
     return false;
   }
 
   size_t region_marked_bytes() const { return _region_marked_bytes; }
-
-  // Debugging
-  size_t tot_words_done() const      { return _tot_words_done; }
-  size_t tot_live() const            { return _tot_live; }
-  size_t tot_used() const            { return _tot_used; }
 };
 
 // Heap region closure used for verifying the counting data
@@ -1574,10 +1555,6 @@ class FinalCountDataUpdateClosure: public HeapRegionClosure {
   BitMap* _region_bm;
   BitMap* _card_bm;
 
-  size_t _total_live_bytes;
-  size_t _total_used_bytes;
-  size_t _total_words_done;
-
   void set_card_bitmap_range(BitMap::idx_t start_idx, BitMap::idx_t last_idx) {
     assert(start_idx <= last_idx, "sanity");
 
@@ -1621,8 +1598,7 @@ class FinalCountDataUpdateClosure: public HeapRegionClosure {
   FinalCountDataUpdateClosure(ConcurrentMark* cm,
                               BitMap* region_bm,
                               BitMap* card_bm) :
-    _cm(cm), _region_bm(region_bm), _card_bm(card_bm),
-    _total_words_done(0), _total_live_bytes(0), _total_used_bytes(0) { }
+    _cm(cm), _region_bm(region_bm), _card_bm(card_bm) { }
 
   bool doHeapRegion(HeapRegion* hr) {
 
@@ -1644,8 +1620,6 @@ class FinalCountDataUpdateClosure: public HeapRegionClosure {
     assert(hr->bottom() <= start && start <= hr->end() &&
            hr->bottom() <= ntams && ntams <= hr->end(), "Preconditions.");
 
-    size_t words_done = ntams - hr->bottom();
-
     if (start < ntams) {
       // Region was changed between remark and cleanup pauses
       // We need to add (ntams - start) to the marked bytes
@@ -1676,16 +1650,8 @@ class FinalCountDataUpdateClosure: public HeapRegionClosure {
       set_bit_for_region(hr);
     }
 
-    _total_words_done += words_done;
-    _total_used_bytes += hr->used();
-    _total_live_bytes += hr->next_marked_bytes();
-
     return false;
   }
-
-  size_t total_words_done() const { return _total_words_done; }
-  size_t total_live_bytes() const { return _total_live_bytes; }
-  size_t total_used_bytes() const { return _total_used_bytes; }
 };
 
 class G1ParFinalCountTask: public AbstractGangTask {
@@ -1697,9 +1663,6 @@ protected:
 
   uint    _n_workers;
 
-  size_t *_live_bytes;
-  size_t *_used_bytes;
-
 public:
   G1ParFinalCountTask(G1CollectedHeap* g1h, BitMap* region_bm, BitMap* card_bm)
     : AbstractGangTask("G1 final counting"),
@@ -1707,8 +1670,7 @@ public:
       _actual_region_bm(region_bm), _actual_card_bm(card_bm),
       _n_workers(0) {
     // Use the value already set as the number of active threads
-    // in the call to run_task().  Needed for the allocation of
-    // _live_bytes and _used_bytes.
+    // in the call to run_task().
     if (G1CollectedHeap::use_parallel_gc_threads()) {
       assert( _g1h->workers()->active_workers() > 0,
         "Should have been previously set");
@@ -1716,14 +1678,6 @@ public:
     } else {
       _n_workers = 1;
     }
-
-    _live_bytes = NEW_C_HEAP_ARRAY(size_t, (size_t) _n_workers);
-    _used_bytes = NEW_C_HEAP_ARRAY(size_t, (size_t) _n_workers);
-  }
-
-  ~G1ParFinalCountTask() {
-    FREE_C_HEAP_ARRAY(size_t, _live_bytes);
-    FREE_C_HEAP_ARRAY(size_t, _used_bytes);
   }
 
   void work(uint worker_id) {
@@ -1741,23 +1695,6 @@ public:
     } else {
       _g1h->heap_region_iterate(&final_update_cl);
     }
-
-    _live_bytes[worker_id] = final_update_cl.total_live_bytes();
-    _used_bytes[worker_id] = final_update_cl.total_used_bytes();
-  }
-
-  size_t live_bytes()  {
-    size_t live_bytes = 0;
-    for (uint i = 0; i < _n_workers; ++i)
-      live_bytes += _live_bytes[i];
-    return live_bytes;
-  }
-
-  size_t used_bytes()  {
-    size_t used_bytes = 0;
-    for (uint i = 0; i < _n_workers; ++i)
-      used_bytes += _used_bytes[i];
-    return used_bytes;
   }
 };
 
@@ -1892,15 +1829,6 @@ public:
 
       HeapRegionRemSet::finish_cleanup_task(&hrrs_cleanup_task);
     }
-    double end = os::elapsedTime();
-    if (G1PrintParCleanupStats) {
-      gclog_or_tty->print("     Worker thread %d [%8.3f..%8.3f = %8.3f ms] "
-                          "claimed %u regions (tot = %8.3f ms, max = %8.3f ms).\n",
-                          worker_id, start, end, (end-start)*1000.0,
-                          g1_note_end.regions_claimed(),
-                          g1_note_end.claimed_region_time_sec()*1000.0,
-                          g1_note_end.max_region_time_sec()*1000.0);
-    }
   }
   size_t max_live_bytes() { return _max_live_bytes; }
   size_t freed_bytes() { return _freed_bytes; }
@@ -2011,29 +1939,11 @@ void ConcurrentMark::cleanup() {
     guarantee(g1_par_verify_task.failures() == 0, "Unexpected accounting failures");
   }
 
-  size_t known_garbage_bytes =
-    g1_par_count_task.used_bytes() - g1_par_count_task.live_bytes();
-  g1p->set_known_garbage_bytes(known_garbage_bytes);
-
   size_t start_used_bytes = g1h->used();
   g1h->set_marking_complete();
 
-  ergo_verbose4(ErgoConcCycles,
-           "finish cleanup",
-           ergo_format_byte("occupancy")
-           ergo_format_byte("capacity")
-           ergo_format_byte_perc("known garbage"),
-           start_used_bytes, g1h->capacity(),
-           known_garbage_bytes,
-           ((double) known_garbage_bytes / (double) g1h->capacity()) * 100.0);
-
   double count_end = os::elapsedTime();
   double this_final_counting_time = (count_end - start);
-  if (G1PrintParCleanupStats) {
-    gclog_or_tty->print_cr("Cleanup:");
-    gclog_or_tty->print_cr("  Finalize counting: %8.3f ms",
-                           this_final_counting_time*1000.0);
-  }
   _total_counting_time += this_final_counting_time;
 
   if (G1PrintRegionLivenessInfo) {
@@ -2047,7 +1957,6 @@ void ConcurrentMark::cleanup() {
   g1h->reset_gc_time_stamp();
 
   // Note end of marking in all heap regions.
-  double note_end_start = os::elapsedTime();
   G1ParNoteEndTask g1_par_note_end_task(g1h, &_cleanup_list);
   if (G1CollectedHeap::use_parallel_gc_threads()) {
     g1h->set_par_threads((int)n_workers);
@@ -2066,11 +1975,6 @@ void ConcurrentMark::cleanup() {
     // regions that there will be more free regions coming soon.
     g1h->set_free_regions_coming();
   }
-  double note_end_end = os::elapsedTime();
-  if (G1PrintParCleanupStats) {
-    gclog_or_tty->print_cr("  note end of marking: %8.3f ms.",
-                           (note_end_end - note_end_start)*1000.0);
-  }
 
   // call below, since it affects the metric by which we sort the heap
   // regions.
@@ -2109,9 +2013,6 @@ void ConcurrentMark::cleanup() {
                                g1h->capacity());
   }
 
-  size_t cleaned_up_bytes = start_used_bytes - g1h->used();
-  g1p->decrease_known_garbage_bytes(cleaned_up_bytes);
-
   // Clean up will have freed any regions completely full of garbage.
   // Update the soft reference policy with the new heap occupancy.
   Universe::update_heap_info_at_gc();
diff --git a/src/share/vm/gc_implementation/g1/g1CollectedHeap.cpp b/src/share/vm/gc_implementation/g1/g1CollectedHeap.cpp
index 924296718e81af8ff69ccb674453c663bff57157..2711a52d01bb36a4a5deba24d9293cf145fe52f9 100644
--- a/src/share/vm/gc_implementation/g1/g1CollectedHeap.cpp
+++ b/src/share/vm/gc_implementation/g1/g1CollectedHeap.cpp
@@ -4064,7 +4064,6 @@ void G1CollectedHeap::finalize_for_evac_failure() {
 
 void G1CollectedHeap::remove_self_forwarding_pointers() {
   assert(check_cset_heap_region_claim_values(HeapRegion::InitialClaimValue), "sanity");
-  assert(g1_policy()->assertMarkedBytesDataOK(), "Should be!");
 
   G1ParRemoveSelfForwardPtrsTask rsfp_task(this);
 
@@ -4082,7 +4081,6 @@ void G1CollectedHeap::remove_self_forwarding_pointers() {
   reset_cset_heap_region_claim_values();
 
   assert(check_cset_heap_region_claim_values(HeapRegion::InitialClaimValue), "sanity");
-  assert(g1_policy()->assertMarkedBytesDataOK(), "Should be!");
 
   // Now restore saved marks, if any.
   if (_objs_with_preserved_marks != NULL) {
diff --git a/src/share/vm/gc_implementation/g1/g1CollectorPolicy.cpp b/src/share/vm/gc_implementation/g1/g1CollectorPolicy.cpp
index 44409fee47196029972a8d1a02f67275e199ca4a..d656f260ba16a2eff897b46d0d61ddd8d13f7dcc 100644
--- a/src/share/vm/gc_implementation/g1/g1CollectorPolicy.cpp
+++ b/src/share/vm/gc_implementation/g1/g1CollectorPolicy.cpp
@@ -192,11 +192,6 @@ G1CollectorPolicy::G1CollectorPolicy() :
   _in_marking_window(false),
   _in_marking_window_im(false),
 
-  _known_garbage_ratio(0.0),
-  _known_garbage_bytes(0),
-
-  _young_gc_eff_seq(new TruncatedSeq(TruncatedSeqLength)),
-
   _recent_prev_end_times_for_all_gcs_sec(
                                 new TruncatedSeq(NumPrevPausesForHeuristics)),
 
@@ -868,8 +863,6 @@ void G1CollectorPolicy::record_full_collection_end() {
   _last_young_gc = false;
   clear_initiate_conc_mark_if_possible();
   clear_during_initial_mark_pause();
-  _known_garbage_bytes = 0;
-  _known_garbage_ratio = 0.0;
   _in_marking_window = false;
   _in_marking_window_im = false;
 
@@ -882,7 +875,7 @@ void G1CollectorPolicy::record_full_collection_end() {
   // Reset survivors SurvRateGroup.
   _survivor_surv_rate_group->reset();
   update_young_list_target_length();
-  _collectionSetChooser->clearMarkedHeapRegions();
+  _collectionSetChooser->clear();
 }
 
 void G1CollectorPolicy::record_stop_world_start() {
@@ -1456,16 +1449,6 @@ void G1CollectorPolicy::record_collection_pause_end(int no_of_gc_threads) {
     }
   }
 
-  // Update the efficiency-since-mark vars.
-  double proc_ms = elapsed_ms * (double) _parallel_gc_threads;
-  if (elapsed_ms < MIN_TIMER_GRANULARITY) {
-    // This usually happens due to the timer not having the required
-    // granularity. Some Linuxes are the usual culprits.
-    // We'll just set it to something (arbitrarily) small.
-    proc_ms = 1.0;
-  }
-  double cur_efficiency = (double) freed_bytes / proc_ms;
-
   bool new_in_marking_window = _in_marking_window;
   bool new_in_marking_window_im = false;
   if (during_initial_mark_pause()) {
@@ -1500,10 +1483,6 @@ void G1CollectorPolicy::record_collection_pause_end(int no_of_gc_threads) {
     }
   }
 
-  if (_last_gc_was_young && !_during_marking) {
-    _young_gc_eff_seq->add(cur_efficiency);
-  }
-
   _short_lived_surv_rate_group->start_adding_regions();
   // do that for any other surv rate groupsx
 
@@ -1618,7 +1597,7 @@ void G1CollectorPolicy::record_collection_pause_end(int no_of_gc_threads) {
   double update_rs_time_goal_ms = _mmu_tracker->max_gc_time() * MILLIUNITS * G1RSetUpdatingPauseTimePercent / 100.0;
   adjust_concurrent_refinement(update_rs_time, update_rs_processed_buffers, update_rs_time_goal_ms);
 
-  assert(assertMarkedBytesDataOK(), "Marked regions not OK at pause end.");
+  _collectionSetChooser->verify();
 }
 
 #define EXT_SIZE_FORMAT "%d%s"
@@ -2065,28 +2044,6 @@ void G1CollectorPolicy::update_survivors_policy() {
         HeapRegion::GrainWords * _max_survivor_regions);
 }
 
-#ifndef PRODUCT
-class HRSortIndexIsOKClosure: public HeapRegionClosure {
-  CollectionSetChooser* _chooser;
-public:
-  HRSortIndexIsOKClosure(CollectionSetChooser* chooser) :
-    _chooser(chooser) {}
-
-  bool doHeapRegion(HeapRegion* r) {
-    if (!r->continuesHumongous()) {
-      assert(_chooser->regionProperlyOrdered(r), "Ought to be.");
-    }
-    return false;
-  }
-};
-
-bool G1CollectorPolicy::assertMarkedBytesDataOK() {
-  HRSortIndexIsOKClosure cl(_collectionSetChooser);
-  _g1->heap_region_iterate(&cl);
-  return true;
-}
-#endif
-
 bool G1CollectorPolicy::force_initial_mark_if_outside_cycle(
                                                      GCCause::Cause gc_cause) {
   bool during_cycle = _g1->concurrent_mark()->cmThread()->during_cycle();
@@ -2184,8 +2141,8 @@ public:
       // We will skip any region that's currently used as an old GC
       // alloc region (we should not consider those for collection
       // before we fill them up).
-      if (_hrSorted->shouldAdd(r) && !_g1h->is_old_gc_alloc_region(r)) {
-        _hrSorted->addMarkedHeapRegion(r);
+      if (_hrSorted->should_add(r) && !_g1h->is_old_gc_alloc_region(r)) {
+        _hrSorted->add_region(r);
       }
     }
     return false;
@@ -2195,16 +2152,14 @@ public:
 class ParKnownGarbageHRClosure: public HeapRegionClosure {
   G1CollectedHeap* _g1h;
   CollectionSetChooser* _hrSorted;
-  jint _marked_regions_added;
+  uint _marked_regions_added;
   size_t _reclaimable_bytes_added;
-  jint _chunk_size;
-  jint _cur_chunk_idx;
-  jint _cur_chunk_end; // Cur chunk [_cur_chunk_idx, _cur_chunk_end)
-  int _worker;
-  int _invokes;
+  uint _chunk_size;
+  uint _cur_chunk_idx;
+  uint _cur_chunk_end; // Cur chunk [_cur_chunk_idx, _cur_chunk_end)
 
   void get_new_chunk() {
-    _cur_chunk_idx = _hrSorted->getParMarkedHeapRegionChunk(_chunk_size);
+    _cur_chunk_idx = _hrSorted->claim_array_chunk(_chunk_size);
     _cur_chunk_end = _cur_chunk_idx + _chunk_size;
   }
   void add_region(HeapRegion* r) {
@@ -2212,7 +2167,7 @@ class ParKnownGarbageHRClosure: public HeapRegionClosure {
       get_new_chunk();
     }
     assert(_cur_chunk_idx < _cur_chunk_end, "postcondition");
-    _hrSorted->setMarkedHeapRegion(_cur_chunk_idx, r);
+    _hrSorted->set_region(_cur_chunk_idx, r);
     _marked_regions_added++;
     _reclaimable_bytes_added += r->reclaimable_bytes();
     _cur_chunk_idx++;
@@ -2220,78 +2175,55 @@ class ParKnownGarbageHRClosure: public HeapRegionClosure {
 
 public:
   ParKnownGarbageHRClosure(CollectionSetChooser* hrSorted,
-                           jint chunk_size,
-                           int worker) :
+                           uint chunk_size) :
       _g1h(G1CollectedHeap::heap()),
-      _hrSorted(hrSorted), _chunk_size(chunk_size), _worker(worker),
+      _hrSorted(hrSorted), _chunk_size(chunk_size),
       _marked_regions_added(0), _reclaimable_bytes_added(0),
-      _cur_chunk_idx(0), _cur_chunk_end(0), _invokes(0) { }
+      _cur_chunk_idx(0), _cur_chunk_end(0) { }
 
   bool doHeapRegion(HeapRegion* r) {
-    // We only include humongous regions in collection
-    // sets when concurrent mark shows that their contained object is
-    // unreachable.
-    _invokes++;
-
     // Do we have any marking information for this region?
     if (r->is_marked()) {
       // We will skip any region that's currently used as an old GC
       // alloc region (we should not consider those for collection
       // before we fill them up).
-      if (_hrSorted->shouldAdd(r) && !_g1h->is_old_gc_alloc_region(r)) {
+      if (_hrSorted->should_add(r) && !_g1h->is_old_gc_alloc_region(r)) {
         add_region(r);
       }
     }
     return false;
   }
-  jint marked_regions_added() { return _marked_regions_added; }
+  uint marked_regions_added() { return _marked_regions_added; }
   size_t reclaimable_bytes_added() { return _reclaimable_bytes_added; }
-  int invokes() { return _invokes; }
 };
 
 class ParKnownGarbageTask: public AbstractGangTask {
   CollectionSetChooser* _hrSorted;
-  jint _chunk_size;
+  uint _chunk_size;
   G1CollectedHeap* _g1;
 public:
-  ParKnownGarbageTask(CollectionSetChooser* hrSorted, jint chunk_size) :
+  ParKnownGarbageTask(CollectionSetChooser* hrSorted, uint chunk_size) :
     AbstractGangTask("ParKnownGarbageTask"),
     _hrSorted(hrSorted), _chunk_size(chunk_size),
     _g1(G1CollectedHeap::heap()) { }
 
   void work(uint worker_id) {
-    ParKnownGarbageHRClosure parKnownGarbageCl(_hrSorted,
-                                               _chunk_size,
-                                               worker_id);
+    ParKnownGarbageHRClosure parKnownGarbageCl(_hrSorted, _chunk_size);
+
     // Back to zero for the claim value.
     _g1->heap_region_par_iterate_chunked(&parKnownGarbageCl, worker_id,
                                          _g1->workers()->active_workers(),
                                          HeapRegion::InitialClaimValue);
-    jint regions_added = parKnownGarbageCl.marked_regions_added();
+    uint regions_added = parKnownGarbageCl.marked_regions_added();
     size_t reclaimable_bytes_added =
                                    parKnownGarbageCl.reclaimable_bytes_added();
-    _hrSorted->updateTotals(regions_added, reclaimable_bytes_added);
-    if (G1PrintParCleanupStats) {
-      gclog_or_tty->print_cr("     Thread %d called %d times, added %d regions to list.",
-                 worker_id, parKnownGarbageCl.invokes(), regions_added);
-    }
+    _hrSorted->update_totals(regions_added, reclaimable_bytes_added);
   }
 };
 
 void
 G1CollectorPolicy::record_concurrent_mark_cleanup_end(int no_of_gc_threads) {
-  double start_sec;
-  if (G1PrintParCleanupStats) {
-    start_sec = os::elapsedTime();
-  }
-
-  _collectionSetChooser->clearMarkedHeapRegions();
-  double clear_marked_end_sec;
-  if (G1PrintParCleanupStats) {
-    clear_marked_end_sec = os::elapsedTime();
-    gclog_or_tty->print_cr("  clear marked regions: %8.3f ms.",
-                           (clear_marked_end_sec - start_sec) * 1000.0);
-  }
+  _collectionSetChooser->clear();
 
   uint region_num = _g1->n_regions();
   if (G1CollectedHeap::use_parallel_gc_threads()) {
@@ -2314,8 +2246,8 @@ G1CollectorPolicy::record_concurrent_mark_cleanup_end(int no_of_gc_threads) {
         MAX2(region_num / (uint) (ParallelGCThreads * OverpartitionFactor),
              MinWorkUnit);
     }
-    _collectionSetChooser->prepareForAddMarkedHeapRegionsPar(_g1->n_regions(),
-                                                             WorkUnit);
+    _collectionSetChooser->prepare_for_par_region_addition(_g1->n_regions(),
+                                                           WorkUnit);
     ParKnownGarbageTask parKnownGarbageTask(_collectionSetChooser,
                                             (int) WorkUnit);
     _g1->workers()->run_task(&parKnownGarbageTask);
@@ -2326,20 +2258,10 @@ G1CollectorPolicy::record_concurrent_mark_cleanup_end(int no_of_gc_threads) {
     KnownGarbageClosure knownGarbagecl(_collectionSetChooser);
     _g1->heap_region_iterate(&knownGarbagecl);
   }
-  double known_garbage_end_sec;
-  if (G1PrintParCleanupStats) {
-    known_garbage_end_sec = os::elapsedTime();
-    gclog_or_tty->print_cr("  compute known garbage: %8.3f ms.",
-                      (known_garbage_end_sec - clear_marked_end_sec) * 1000.0);
-  }
 
-  _collectionSetChooser->sortMarkedHeapRegions();
-  double end_sec = os::elapsedTime();
-  if (G1PrintParCleanupStats) {
-    gclog_or_tty->print_cr("  sorting: %8.3f ms.",
-                           (end_sec - known_garbage_end_sec) * 1000.0);
-  }
+  _collectionSetChooser->sort_regions();
 
+  double end_sec = os::elapsedTime();
   double elapsed_time_ms = (end_sec - _mark_cleanup_start_sec) * 1000.0;
   _concurrent_mark_cleanup_times_ms->add(elapsed_time_ms);
   _cur_mark_stop_world_time_ms += elapsed_time_ms;
@@ -2555,13 +2477,13 @@ void G1CollectorPolicy::print_collection_set(HeapRegion* list_head, outputStream
 bool G1CollectorPolicy::next_gc_should_be_mixed(const char* true_action_str,
                                                 const char* false_action_str) {
   CollectionSetChooser* cset_chooser = _collectionSetChooser;
-  if (cset_chooser->isEmpty()) {
+  if (cset_chooser->is_empty()) {
     ergo_verbose0(ErgoMixedGCs,
                   false_action_str,
                   ergo_format_reason("candidate old regions not available"));
     return false;
   }
-  size_t reclaimable_bytes = cset_chooser->remainingReclaimableBytes();
+  size_t reclaimable_bytes = cset_chooser->remaining_reclaimable_bytes();
   size_t capacity_bytes = _g1->capacity();
   double perc = (double) reclaimable_bytes * 100.0 / (double) capacity_bytes;
   double threshold = (double) G1HeapWastePercent;
@@ -2572,7 +2494,7 @@ bool G1CollectorPolicy::next_gc_should_be_mixed(const char* true_action_str,
               ergo_format_region("candidate old regions")
               ergo_format_byte_perc("reclaimable")
               ergo_format_perc("threshold"),
-              cset_chooser->remainingRegions(),
+              cset_chooser->remaining_regions(),
               reclaimable_bytes, perc, threshold);
     return false;
   }
@@ -2583,7 +2505,7 @@ bool G1CollectorPolicy::next_gc_should_be_mixed(const char* true_action_str,
                 ergo_format_region("candidate old regions")
                 ergo_format_byte_perc("reclaimable")
                 ergo_format_perc("threshold"),
-                cset_chooser->remainingRegions(),
+                cset_chooser->remaining_regions(),
                 reclaimable_bytes, perc, threshold);
   return true;
 }
@@ -2666,9 +2588,9 @@ void G1CollectorPolicy::finalize_cset(double target_pause_time_ms) {
 
   if (!gcs_are_young()) {
     CollectionSetChooser* cset_chooser = _collectionSetChooser;
-    assert(cset_chooser->verify(), "CSet Chooser verification - pre");
-    const uint min_old_cset_length = cset_chooser->calcMinOldCSetLength();
-    const uint max_old_cset_length = cset_chooser->calcMaxOldCSetLength();
+    cset_chooser->verify();
+    const uint min_old_cset_length = cset_chooser->calc_min_old_cset_length();
+    const uint max_old_cset_length = cset_chooser->calc_max_old_cset_length();
 
     uint expensive_region_num = 0;
     bool check_time_remaining = adaptive_young_list_length();
@@ -2755,7 +2677,7 @@ void G1CollectorPolicy::finalize_cset(double target_pause_time_ms) {
                     time_remaining_ms);
     }
 
-    assert(cset_chooser->verify(), "CSet Chooser verification - post");
+    cset_chooser->verify();
   }
 
   stop_incremental_cset_building();
diff --git a/src/share/vm/gc_implementation/g1/g1CollectorPolicy.hpp b/src/share/vm/gc_implementation/g1/g1CollectorPolicy.hpp
index f897ffdb64459a40be2da91f802bd92765e44dba..7cdf79d7febd00602431a9f74d6dfcb7400b5c38 100644
--- a/src/share/vm/gc_implementation/g1/g1CollectorPolicy.hpp
+++ b/src/share/vm/gc_implementation/g1/g1CollectorPolicy.hpp
@@ -288,8 +288,6 @@ private:
 
   TruncatedSeq* _cost_per_byte_ms_during_cm_seq;
 
-  TruncatedSeq* _young_gc_eff_seq;
-
   G1YoungGenSizer* _young_gen_sizer;
 
   uint _eden_cset_region_length;
@@ -315,9 +313,6 @@ private:
 
   size_t _rs_lengths_prediction;
 
-  size_t _known_garbage_bytes;
-  double _known_garbage_ratio;
-
   double sigma() { return _sigma; }
 
   // A function that prevents us putting too much stock in small sample
@@ -509,10 +504,6 @@ public:
     _recorded_non_young_free_cset_time_ms = time_ms;
   }
 
-  double predict_young_gc_eff() {
-    return get_new_neg_prediction(_young_gc_eff_seq);
-  }
-
   double predict_survivor_regions_evac_time();
 
   void cset_regions_freed() {
@@ -522,20 +513,6 @@ public:
     // also call it on any more surv rate groups
   }
 
-  void set_known_garbage_bytes(size_t known_garbage_bytes) {
-    _known_garbage_bytes = known_garbage_bytes;
-    size_t heap_bytes = _g1->capacity();
-    _known_garbage_ratio = (double) _known_garbage_bytes / (double) heap_bytes;
-  }
-
-  void decrease_known_garbage_bytes(size_t known_garbage_bytes) {
-    guarantee( _known_garbage_bytes >= known_garbage_bytes, "invariant" );
-
-    _known_garbage_bytes -= known_garbage_bytes;
-    size_t heap_bytes = _g1->capacity();
-    _known_garbage_ratio = (double) _known_garbage_bytes / (double) heap_bytes;
-  }
-
   G1MMUTracker* mmu_tracker() {
     return _mmu_tracker;
   }
@@ -1026,12 +1003,6 @@ public:
   // exceeded the desired limit, return an amount to expand by.
   size_t expansion_amount();
 
-#ifndef PRODUCT
-  // Check any appropriate marked bytes info, asserting false if
-  // something's wrong, else returning "true".
-  bool assertMarkedBytesDataOK();
-#endif
-
   // Print tracing information.
   void print_tracing_info() const;
 
@@ -1074,19 +1045,6 @@ public:
     return _young_gen_sizer->adaptive_young_list_length();
   }
 
-  inline double get_gc_eff_factor() {
-    double ratio = _known_garbage_ratio;
-
-    double square = ratio * ratio;
-    // square = square * square;
-    double ret = square * 9.0 + 1.0;
-#if 0
-    gclog_or_tty->print_cr("ratio = %1.2lf, ret = %1.2lf", ratio, ret);
-#endif // 0
-    guarantee(0.0 <= ret && ret < 10.0, "invariant!");
-    return ret;
-  }
-
 private:
   //
   // Survivor regions policy.
diff --git a/src/share/vm/gc_implementation/g1/g1_globals.hpp b/src/share/vm/gc_implementation/g1/g1_globals.hpp
index d25e5b947227e84eaaeb21e3c6ce721178e7d807..0378688c0159220270fedc9828aba05d968b48d8 100644
--- a/src/share/vm/gc_implementation/g1/g1_globals.hpp
+++ b/src/share/vm/gc_implementation/g1/g1_globals.hpp
@@ -127,9 +127,6 @@
             "Prints the liveness information for all regions in the heap "  \
             "at the end of a marking cycle.")                               \
                                                                             \
-  develop(bool, G1PrintParCleanupStats, false,                              \
-          "When true, print extra stats about parallel cleanup.")           \
-                                                                            \
   product(intx, G1UpdateBufferSize, 256,                                    \
           "Size of an update buffer")                                       \
                                                                             \
diff --git a/src/share/vm/gc_implementation/g1/heapRegion.cpp b/src/share/vm/gc_implementation/g1/heapRegion.cpp
index 44e3ac8334630c78f719fbdf6c56e98d346e502b..09b80cce581427fd5779a54f7decdcab45516fe6 100644
--- a/src/share/vm/gc_implementation/g1/heapRegion.cpp
+++ b/src/share/vm/gc_implementation/g1/heapRegion.cpp
@@ -370,7 +370,6 @@ void HeapRegion::hr_clear(bool par, bool clear_space) {
     _claimed = InitialClaimValue;
   }
   zero_marked_bytes();
-  set_sort_index(-1);
 
   _offsets.resize(HeapRegion::GrainWords);
   init_top_at_mark_start();
@@ -491,8 +490,7 @@ HeapRegion::HeapRegion(uint hrs_index,
     _in_collection_set(false),
     _next_in_special_set(NULL), _orig_end(NULL),
     _claimed(InitialClaimValue), _evacuation_failed(false),
-    _prev_marked_bytes(0), _next_marked_bytes(0), _sort_index(-1),
-    _gc_efficiency(0.0),
+    _prev_marked_bytes(0), _next_marked_bytes(0), _gc_efficiency(0.0),
     _young_type(NotYoung), _next_young_region(NULL),
     _next_dirty_cards_region(NULL), _next(NULL), _pending_removal(false),
 #ifdef ASSERT
diff --git a/src/share/vm/gc_implementation/g1/heapRegion.hpp b/src/share/vm/gc_implementation/g1/heapRegion.hpp
index 8a99d2d3f7bcd6f2a755a0d8d397797f6e9477b9..cd6e164e136e7d8bc88f3cdf5ae2c1ad520dd5a2 100644
--- a/src/share/vm/gc_implementation/g1/heapRegion.hpp
+++ b/src/share/vm/gc_implementation/g1/heapRegion.hpp
@@ -281,12 +281,8 @@ class HeapRegion: public G1OffsetTableContigSpace {
   size_t _prev_marked_bytes;    // Bytes known to be live via last completed marking.
   size_t _next_marked_bytes;    // Bytes known to be live via in-progress marking.
 
-  // See "sort_index" method.  -1 means is not in the array.
-  int _sort_index;
-
-  // <PREDICTION>
+  // The calculated GC efficiency of the region.
   double _gc_efficiency;
-  // </PREDICTION>
 
   enum YoungType {
     NotYoung,                   // a region is not young
@@ -629,16 +625,6 @@ class HeapRegion: public G1OffsetTableContigSpace {
   // last mark phase ended.
   bool is_marked() { return _prev_top_at_mark_start != bottom(); }
 
-  // If "is_marked()" is true, then this is the index of the region in
-  // an array constructed at the end of marking of the regions in a
-  // "desirability" order.
-  int sort_index() {
-    return _sort_index;
-  }
-  void set_sort_index(int i) {
-    _sort_index = i;
-  }
-
   void init_top_at_conc_mark_count() {
     _top_at_conc_mark_count = bottom();
   }