--- old/src/share/vm/gc_implementation/g1/heapRegionRemSet.cpp	2014-02-13 17:48:06.817769688 +0100
+++ new/src/share/vm/gc_implementation/g1/heapRegionRemSet.cpp	2014-02-13 17:48:06.481769697 +0100
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2001, 2013, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2001, 2014, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -259,10 +259,9 @@
 size_t OtherRegionsTable::_fine_eviction_stride = 0;
 size_t OtherRegionsTable::_fine_eviction_sample_size = 0;
 
-OtherRegionsTable::OtherRegionsTable(HeapRegion* hr) :
+OtherRegionsTable::OtherRegionsTable(HeapRegion* hr, Mutex* m) :
   _g1h(G1CollectedHeap::heap()),
-  _m(Mutex::leaf, "An OtherRegionsTable lock", true),
-  _hr(hr),
+  _hr(hr), _m(m),
   _coarse_map(G1CollectedHeap::heap()->max_regions(),
               false /* in-resource-area */),
   _fine_grain_regions(NULL),
@@ -363,17 +362,18 @@
 size_t OtherRegionsTable::_from_card_cache_mem_size = 0;
 
 void OtherRegionsTable::init_from_card_cache(size_t max_regions) {
-  _from_card_cache_max_regions = max_regions;
+  // pad rows to cache line sizes.
+  _from_card_cache_max_regions = align_size_up(max_regions, DEFAULT_CACHE_LINE_SIZE / sizeof(int));
 
   int n_par_rs = HeapRegionRemSet::num_par_rem_sets();
   _from_card_cache = NEW_C_HEAP_ARRAY(int*, n_par_rs, mtGC);
   for (int i = 0; i < n_par_rs; i++) {
-    _from_card_cache[i] = NEW_C_HEAP_ARRAY(int, max_regions, mtGC);
-    for (size_t j = 0; j < max_regions; j++) {
+    _from_card_cache[i] = NEW_C_HEAP_ARRAY(int, _from_card_cache_max_regions, mtGC);
+    for (size_t j = 0; j < _from_card_cache_max_regions; j++) {
       _from_card_cache[i][j] = -1;  // An invalid value.
     }
   }
-  _from_card_cache_mem_size = n_par_rs * max_regions * sizeof(int);
+  _from_card_cache_mem_size = n_par_rs * _from_card_cache_max_regions * sizeof(int);
 }
 
 void OtherRegionsTable::shrink_from_card_cache(size_t new_n_regs) {
@@ -442,7 +442,7 @@
   size_t ind = from_hrs_ind & _mod_max_fine_entries_mask;
   PerRegionTable* prt = find_region_table(ind, from_hr);
   if (prt == NULL) {
-    MutexLockerEx x(&_m, Mutex::_no_safepoint_check_flag);
+    MutexLockerEx x(_m, Mutex::_no_safepoint_check_flag);
     // Confirm that it's really not there...
     prt = find_region_table(ind, from_hr);
     if (prt == NULL) {
@@ -544,7 +544,7 @@
 jint OtherRegionsTable::_n_coarsenings = 0;
 
 PerRegionTable* OtherRegionsTable::delete_region_table() {
-  assert(_m.owned_by_self(), "Precondition");
+  assert(_m->owned_by_self(), "Precondition");
   assert(_n_fine_entries == _max_fine_entries, "Precondition");
   PerRegionTable* max = NULL;
   jint max_occ = 0;
@@ -676,8 +676,6 @@
 
 
 size_t OtherRegionsTable::occupied() const {
-  // Cast away const in this case.
-  MutexLockerEx x((Mutex*)&_m, Mutex::_no_safepoint_check_flag);
   size_t sum = occ_fine();
   sum += occ_sparse();
   sum += occ_coarse();
@@ -707,8 +705,7 @@
 }
 
 size_t OtherRegionsTable::mem_size() const {
-  // Cast away const in this case.
-  MutexLockerEx x((Mutex*)&_m, Mutex::_no_safepoint_check_flag);
+  MutexLockerEx x(_m, Mutex::_no_safepoint_check_flag);
   size_t sum = 0;
   // all PRTs are of the same size so it is sufficient to query only one of them.
   if (_first_all_fine_prts != NULL) {
@@ -733,13 +730,13 @@
 
 void OtherRegionsTable::clear_fcc() {
   size_t hrs_idx = hr()->hrs_index();
-  for (int i = 0; i < HeapRegionRemSet::num_par_rem_sets(); i++) {
+  uint num_par_remsets = HeapRegionRemSet::num_par_rem_sets();
+  for (uint i = 0; i < num_par_remsets; i++) {
     _from_card_cache[i][hrs_idx] = -1;
   }
 }
 
 void OtherRegionsTable::clear() {
-  MutexLockerEx x(&_m, Mutex::_no_safepoint_check_flag);
   // if there are no entries, skip this step
   if (_first_all_fine_prts != NULL) {
     guarantee(_first_all_fine_prts != NULL && _last_all_fine_prts != NULL, "just checking");
@@ -759,7 +756,7 @@
 }
 
 void OtherRegionsTable::clear_incoming_entry(HeapRegion* from_hr) {
-  MutexLockerEx x(&_m, Mutex::_no_safepoint_check_flag);
+  MutexLockerEx x(_m, Mutex::_no_safepoint_check_flag);
   size_t hrs_ind = (size_t) from_hr->hrs_index();
   size_t ind = hrs_ind & _mod_max_fine_entries_mask;
   if (del_single_region_table(ind, from_hr)) {
@@ -804,8 +801,7 @@
 }
 
 bool OtherRegionsTable::contains_reference(OopOrNarrowOopStar from) const {
-  // Cast away const in this case.
-  MutexLockerEx x((Mutex*)&_m, Mutex::_no_safepoint_check_flag);
+  MutexLockerEx x(_m, Mutex::_no_safepoint_check_flag);
   return contains_reference_locked(from);
 }
 
@@ -850,7 +846,8 @@
 
 HeapRegionRemSet::HeapRegionRemSet(G1BlockOffsetSharedArray* bosa,
                                    HeapRegion* hr)
-  : _bosa(bosa), _strong_code_roots_list(NULL), _other_regions(hr) {
+  : _bosa(bosa), _m(Mutex::leaf, "An OtherRegionsTable lock", true),
+  _other_regions(hr, &_m), _code_roots() {
   reset_for_par_iteration();
 }
 
@@ -883,7 +880,7 @@
 }
 
 #ifndef PRODUCT
-void HeapRegionRemSet::print() const {
+void HeapRegionRemSet::print() {
   HeapRegionRemSetIterator iter(this);
   size_t card_index;
   while (iter.has_next(card_index)) {
@@ -909,14 +906,14 @@
 }
 
 void HeapRegionRemSet::clear() {
-  if (_strong_code_roots_list != NULL) {
-    delete _strong_code_roots_list;
-  }
-  _strong_code_roots_list = new (ResourceObj::C_HEAP, mtGC)
-                                GrowableArray<nmethod*>(10, 0, NULL, true);
+  MutexLockerEx x(&_m, Mutex::_no_safepoint_check_flag);
+  clear_locked();
+}
 
+void HeapRegionRemSet::clear_locked() {
+  _code_roots.clear();
   _other_regions.clear();
-  assert(occupied() == 0, "Should be clear.");
+  assert(occupied_locked() == 0, "Should be clear.");
   reset_for_par_iteration();
 }
 
@@ -937,22 +934,14 @@
 
 void HeapRegionRemSet::add_strong_code_root(nmethod* nm) {
   assert(nm != NULL, "sanity");
-  // Search for the code blob from the RHS to avoid
-  // duplicate entries as much as possible
-  if (_strong_code_roots_list->find_from_end(nm) < 0) {
-    // Code blob isn't already in the list
-    _strong_code_roots_list->push(nm);
-  }
+  _code_roots.add(nm);
 }
 
 void HeapRegionRemSet::remove_strong_code_root(nmethod* nm) {
   assert(nm != NULL, "sanity");
-  int idx = _strong_code_roots_list->find(nm);
-  if (idx >= 0) {
-    _strong_code_roots_list->remove_at(idx);
-  }
+  _code_roots.remove(nm);
   // Check that there were no duplicates
-  guarantee(_strong_code_roots_list->find(nm) < 0, "duplicate entry found");
+  guarantee(!_code_roots.contains(nm), "duplicate entry found");
 }
 
 class NMethodMigrationOopClosure : public OopClosure {
@@ -1014,8 +1003,8 @@
   GrowableArray<nmethod*> to_be_retained(10);
   G1CollectedHeap* g1h = G1CollectedHeap::heap();
 
-  while (_strong_code_roots_list->is_nonempty()) {
-    nmethod *nm = _strong_code_roots_list->pop();
+  while (!_code_roots.is_empty()) {
+    nmethod *nm = _code_roots.pop();
     if (nm != NULL) {
       NMethodMigrationOopClosure oop_cl(g1h, hr(), nm);
       nm->oops_do(&oop_cl);
@@ -1037,21 +1026,17 @@
   }
 }
 
-void HeapRegionRemSet::strong_code_roots_do(CodeBlobClosure* blk) const {
-  for (int i = 0; i < _strong_code_roots_list->length(); i += 1) {
-    nmethod* nm = _strong_code_roots_list->at(i);
-    blk->do_code_blob(nm);
-  }
+void HeapRegionRemSet::strong_code_roots_do(CodeBlobClosure* blk) {
+  _code_roots.nmethods_do(blk);
 }
 
 size_t HeapRegionRemSet::strong_code_roots_mem_size() {
-  return sizeof(GrowableArray<nmethod*>) +
-         _strong_code_roots_list->max_length() * sizeof(nmethod*);
+  return _code_roots.mem_size();
 }
 
 //-------------------- Iteration --------------------
 
-HeapRegionRemSetIterator:: HeapRegionRemSetIterator(const HeapRegionRemSet* hrrs) :
+HeapRegionRemSetIterator:: HeapRegionRemSetIterator(HeapRegionRemSet* hrrs) :
   _hrrs(hrrs),
   _g1h(G1CollectedHeap::heap()),
   _coarse_map(&hrrs->_other_regions._coarse_map),