hotspot/src/share/vm/gc/shared/collectorPolicy.cpp
changeset 30764 fec48bf5a827
parent 30173 13cf7580b000
child 31236 d4d3011aa98e
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/hotspot/src/share/vm/gc/shared/collectorPolicy.cpp	Wed May 13 15:16:06 2015 +0200
@@ -0,0 +1,1102 @@
+/*
+ * Copyright (c) 2001, 2015, 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
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ *
+ */
+
+#include "precompiled.hpp"
+#include "gc/shared/adaptiveSizePolicy.hpp"
+#include "gc/shared/cardTableRS.hpp"
+#include "gc/shared/collectorPolicy.hpp"
+#include "gc/shared/gcLocker.inline.hpp"
+#include "gc/shared/gcPolicyCounters.hpp"
+#include "gc/shared/genCollectedHeap.hpp"
+#include "gc/shared/generationSpec.hpp"
+#include "gc/shared/space.hpp"
+#include "gc/shared/vmGCOperations.hpp"
+#include "memory/universe.hpp"
+#include "runtime/arguments.hpp"
+#include "runtime/globals_extension.hpp"
+#include "runtime/handles.inline.hpp"
+#include "runtime/java.hpp"
+#include "runtime/thread.inline.hpp"
+#include "runtime/vmThread.hpp"
+#include "utilities/macros.hpp"
+
+// CollectorPolicy methods
+
+CollectorPolicy::CollectorPolicy() :
+    _space_alignment(0),
+    _heap_alignment(0),
+    _initial_heap_byte_size(InitialHeapSize),
+    _max_heap_byte_size(MaxHeapSize),
+    _min_heap_byte_size(Arguments::min_heap_size()),
+    _max_heap_size_cmdline(false),
+    _size_policy(NULL),
+    _should_clear_all_soft_refs(false),
+    _all_soft_refs_clear(false)
+{}
+
+#ifdef ASSERT
+void CollectorPolicy::assert_flags() {
+  assert(InitialHeapSize <= MaxHeapSize, "Ergonomics decided on incompatible initial and maximum heap sizes");
+  assert(InitialHeapSize % _heap_alignment == 0, "InitialHeapSize alignment");
+  assert(MaxHeapSize % _heap_alignment == 0, "MaxHeapSize alignment");
+}
+
+void CollectorPolicy::assert_size_info() {
+  assert(InitialHeapSize == _initial_heap_byte_size, "Discrepancy between InitialHeapSize flag and local storage");
+  assert(MaxHeapSize == _max_heap_byte_size, "Discrepancy between MaxHeapSize flag and local storage");
+  assert(_max_heap_byte_size >= _min_heap_byte_size, "Ergonomics decided on incompatible minimum and maximum heap sizes");
+  assert(_initial_heap_byte_size >= _min_heap_byte_size, "Ergonomics decided on incompatible initial and minimum heap sizes");
+  assert(_max_heap_byte_size >= _initial_heap_byte_size, "Ergonomics decided on incompatible initial and maximum heap sizes");
+  assert(_min_heap_byte_size % _heap_alignment == 0, "min_heap_byte_size alignment");
+  assert(_initial_heap_byte_size % _heap_alignment == 0, "initial_heap_byte_size alignment");
+  assert(_max_heap_byte_size % _heap_alignment == 0, "max_heap_byte_size alignment");
+}
+#endif // ASSERT
+
+void CollectorPolicy::initialize_flags() {
+  assert(_space_alignment != 0, "Space alignment not set up properly");
+  assert(_heap_alignment != 0, "Heap alignment not set up properly");
+  assert(_heap_alignment >= _space_alignment,
+         err_msg("heap_alignment: " SIZE_FORMAT " less than space_alignment: " SIZE_FORMAT,
+                 _heap_alignment, _space_alignment));
+  assert(_heap_alignment % _space_alignment == 0,
+         err_msg("heap_alignment: " SIZE_FORMAT " not aligned by space_alignment: " SIZE_FORMAT,
+                 _heap_alignment, _space_alignment));
+
+  if (FLAG_IS_CMDLINE(MaxHeapSize)) {
+    if (FLAG_IS_CMDLINE(InitialHeapSize) && InitialHeapSize > MaxHeapSize) {
+      vm_exit_during_initialization("Initial heap size set to a larger value than the maximum heap size");
+    }
+    if (_min_heap_byte_size != 0 && MaxHeapSize < _min_heap_byte_size) {
+      vm_exit_during_initialization("Incompatible minimum and maximum heap sizes specified");
+    }
+    _max_heap_size_cmdline = true;
+  }
+
+  // Check heap parameter properties
+  if (InitialHeapSize < M) {
+    vm_exit_during_initialization("Too small initial heap");
+  }
+  if (_min_heap_byte_size < M) {
+    vm_exit_during_initialization("Too small minimum heap");
+  }
+
+  // User inputs from -Xmx and -Xms must be aligned
+  _min_heap_byte_size = align_size_up(_min_heap_byte_size, _heap_alignment);
+  size_t aligned_initial_heap_size = align_size_up(InitialHeapSize, _heap_alignment);
+  size_t aligned_max_heap_size = align_size_up(MaxHeapSize, _heap_alignment);
+
+  // Write back to flags if the values changed
+  if (aligned_initial_heap_size != InitialHeapSize) {
+    FLAG_SET_ERGO(size_t, InitialHeapSize, aligned_initial_heap_size);
+  }
+  if (aligned_max_heap_size != MaxHeapSize) {
+    FLAG_SET_ERGO(size_t, MaxHeapSize, aligned_max_heap_size);
+  }
+
+  if (FLAG_IS_CMDLINE(InitialHeapSize) && _min_heap_byte_size != 0 &&
+      InitialHeapSize < _min_heap_byte_size) {
+    vm_exit_during_initialization("Incompatible minimum and initial heap sizes specified");
+  }
+  if (!FLAG_IS_DEFAULT(InitialHeapSize) && InitialHeapSize > MaxHeapSize) {
+    FLAG_SET_ERGO(size_t, MaxHeapSize, InitialHeapSize);
+  } else if (!FLAG_IS_DEFAULT(MaxHeapSize) && InitialHeapSize > MaxHeapSize) {
+    FLAG_SET_ERGO(size_t, InitialHeapSize, MaxHeapSize);
+    if (InitialHeapSize < _min_heap_byte_size) {
+      _min_heap_byte_size = InitialHeapSize;
+    }
+  }
+
+  _initial_heap_byte_size = InitialHeapSize;
+  _max_heap_byte_size = MaxHeapSize;
+
+  FLAG_SET_ERGO(size_t, MinHeapDeltaBytes, align_size_up(MinHeapDeltaBytes, _space_alignment));
+
+  DEBUG_ONLY(CollectorPolicy::assert_flags();)
+}
+
+void CollectorPolicy::initialize_size_info() {
+  if (PrintGCDetails && Verbose) {
+    gclog_or_tty->print_cr("Minimum heap " SIZE_FORMAT "  Initial heap "
+      SIZE_FORMAT "  Maximum heap " SIZE_FORMAT,
+      _min_heap_byte_size, _initial_heap_byte_size, _max_heap_byte_size);
+  }
+
+  DEBUG_ONLY(CollectorPolicy::assert_size_info();)
+}
+
+bool CollectorPolicy::use_should_clear_all_soft_refs(bool v) {
+  bool result = _should_clear_all_soft_refs;
+  set_should_clear_all_soft_refs(false);
+  return result;
+}
+
+GenRemSet* CollectorPolicy::create_rem_set(MemRegion whole_heap) {
+  return new CardTableRS(whole_heap);
+}
+
+void CollectorPolicy::cleared_all_soft_refs() {
+  // If near gc overhear limit, continue to clear SoftRefs.  SoftRefs may
+  // have been cleared in the last collection but if the gc overhear
+  // limit continues to be near, SoftRefs should still be cleared.
+  if (size_policy() != NULL) {
+    _should_clear_all_soft_refs = size_policy()->gc_overhead_limit_near();
+  }
+  _all_soft_refs_clear = true;
+}
+
+size_t CollectorPolicy::compute_heap_alignment() {
+  // The card marking array and the offset arrays for old generations are
+  // committed in os pages as well. Make sure they are entirely full (to
+  // avoid partial page problems), e.g. if 512 bytes heap corresponds to 1
+  // byte entry and the os page size is 4096, the maximum heap size should
+  // be 512*4096 = 2MB aligned.
+
+  size_t alignment = GenRemSet::max_alignment_constraint();
+
+  if (UseLargePages) {
+      // In presence of large pages we have to make sure that our
+      // alignment is large page aware.
+      alignment = lcm(os::large_page_size(), alignment);
+  }
+
+  return alignment;
+}
+
+// GenCollectorPolicy methods
+
+GenCollectorPolicy::GenCollectorPolicy() :
+    _min_young_size(0),
+    _initial_young_size(0),
+    _max_young_size(0),
+    _min_old_size(0),
+    _initial_old_size(0),
+    _max_old_size(0),
+    _gen_alignment(0),
+    _young_gen_spec(NULL),
+    _old_gen_spec(NULL)
+{}
+
+size_t GenCollectorPolicy::scale_by_NewRatio_aligned(size_t base_size) {
+  return align_size_down_bounded(base_size / (NewRatio + 1), _gen_alignment);
+}
+
+size_t GenCollectorPolicy::bound_minus_alignment(size_t desired_size,
+                                                 size_t maximum_size) {
+  size_t max_minus = maximum_size - _gen_alignment;
+  return desired_size < max_minus ? desired_size : max_minus;
+}
+
+
+void GenCollectorPolicy::initialize_size_policy(size_t init_eden_size,
+                                                size_t init_promo_size,
+                                                size_t init_survivor_size) {
+  const double max_gc_pause_sec = ((double) MaxGCPauseMillis) / 1000.0;
+  _size_policy = new AdaptiveSizePolicy(init_eden_size,
+                                        init_promo_size,
+                                        init_survivor_size,
+                                        max_gc_pause_sec,
+                                        GCTimeRatio);
+}
+
+size_t GenCollectorPolicy::young_gen_size_lower_bound() {
+  // The young generation must be aligned and have room for eden + two survivors
+  return align_size_up(3 * _space_alignment, _gen_alignment);
+}
+
+#ifdef ASSERT
+void GenCollectorPolicy::assert_flags() {
+  CollectorPolicy::assert_flags();
+  assert(NewSize >= _min_young_size, "Ergonomics decided on a too small young gen size");
+  assert(NewSize <= MaxNewSize, "Ergonomics decided on incompatible initial and maximum young gen sizes");
+  assert(FLAG_IS_DEFAULT(MaxNewSize) || MaxNewSize < MaxHeapSize, "Ergonomics decided on incompatible maximum young gen and heap sizes");
+  assert(NewSize % _gen_alignment == 0, "NewSize alignment");
+  assert(FLAG_IS_DEFAULT(MaxNewSize) || MaxNewSize % _gen_alignment == 0, "MaxNewSize alignment");
+  assert(OldSize + NewSize <= MaxHeapSize, "Ergonomics decided on incompatible generation and heap sizes");
+  assert(OldSize % _gen_alignment == 0, "OldSize alignment");
+}
+
+void GenCollectorPolicy::assert_size_info() {
+  CollectorPolicy::assert_size_info();
+  // GenCollectorPolicy::initialize_size_info may update the MaxNewSize
+  assert(MaxNewSize < MaxHeapSize, "Ergonomics decided on incompatible maximum young and heap sizes");
+  assert(NewSize == _initial_young_size, "Discrepancy between NewSize flag and local storage");
+  assert(MaxNewSize == _max_young_size, "Discrepancy between MaxNewSize flag and local storage");
+  assert(OldSize == _initial_old_size, "Discrepancy between OldSize flag and local storage");
+  assert(_min_young_size <= _initial_young_size, "Ergonomics decided on incompatible minimum and initial young gen sizes");
+  assert(_initial_young_size <= _max_young_size, "Ergonomics decided on incompatible initial and maximum young gen sizes");
+  assert(_min_young_size % _gen_alignment == 0, "_min_young_size alignment");
+  assert(_initial_young_size % _gen_alignment == 0, "_initial_young_size alignment");
+  assert(_max_young_size % _gen_alignment == 0, "_max_young_size alignment");
+  assert(_min_young_size <= bound_minus_alignment(_min_young_size, _min_heap_byte_size),
+      "Ergonomics made minimum young generation larger than minimum heap");
+  assert(_initial_young_size <=  bound_minus_alignment(_initial_young_size, _initial_heap_byte_size),
+      "Ergonomics made initial young generation larger than initial heap");
+  assert(_max_young_size <= bound_minus_alignment(_max_young_size, _max_heap_byte_size),
+      "Ergonomics made maximum young generation lager than maximum heap");
+  assert(_min_old_size <= _initial_old_size, "Ergonomics decided on incompatible minimum and initial old gen sizes");
+  assert(_initial_old_size <= _max_old_size, "Ergonomics decided on incompatible initial and maximum old gen sizes");
+  assert(_max_old_size % _gen_alignment == 0, "_max_old_size alignment");
+  assert(_initial_old_size % _gen_alignment == 0, "_initial_old_size alignment");
+  assert(_max_heap_byte_size <= (_max_young_size + _max_old_size), "Total maximum heap sizes must be sum of generation maximum sizes");
+  assert(_min_young_size + _min_old_size <= _min_heap_byte_size, "Minimum generation sizes exceed minimum heap size");
+  assert(_initial_young_size + _initial_old_size == _initial_heap_byte_size, "Initial generation sizes should match initial heap size");
+  assert(_max_young_size + _max_old_size == _max_heap_byte_size, "Maximum generation sizes should match maximum heap size");
+}
+#endif // ASSERT
+
+void GenCollectorPolicy::initialize_flags() {
+  CollectorPolicy::initialize_flags();
+
+  assert(_gen_alignment != 0, "Generation alignment not set up properly");
+  assert(_heap_alignment >= _gen_alignment,
+         err_msg("heap_alignment: " SIZE_FORMAT " less than gen_alignment: " SIZE_FORMAT,
+                 _heap_alignment, _gen_alignment));
+  assert(_gen_alignment % _space_alignment == 0,
+         err_msg("gen_alignment: " SIZE_FORMAT " not aligned by space_alignment: " SIZE_FORMAT,
+                 _gen_alignment, _space_alignment));
+  assert(_heap_alignment % _gen_alignment == 0,
+         err_msg("heap_alignment: " SIZE_FORMAT " not aligned by gen_alignment: " SIZE_FORMAT,
+                 _heap_alignment, _gen_alignment));
+
+  // All generational heaps have a youngest gen; handle those flags here
+
+  // Make sure the heap is large enough for two generations
+  size_t smallest_new_size = young_gen_size_lower_bound();
+  size_t smallest_heap_size = align_size_up(smallest_new_size + align_size_up(_space_alignment, _gen_alignment),
+                                           _heap_alignment);
+  if (MaxHeapSize < smallest_heap_size) {
+    FLAG_SET_ERGO(size_t, MaxHeapSize, smallest_heap_size);
+    _max_heap_byte_size = MaxHeapSize;
+  }
+  // If needed, synchronize _min_heap_byte size and _initial_heap_byte_size
+  if (_min_heap_byte_size < smallest_heap_size) {
+    _min_heap_byte_size = smallest_heap_size;
+    if (InitialHeapSize < _min_heap_byte_size) {
+      FLAG_SET_ERGO(size_t, InitialHeapSize, smallest_heap_size);
+      _initial_heap_byte_size = smallest_heap_size;
+    }
+  }
+
+  // Make sure NewSize allows an old generation to fit even if set on the command line
+  if (FLAG_IS_CMDLINE(NewSize) && NewSize >= _initial_heap_byte_size) {
+    warning("NewSize was set larger than initial heap size, will use initial heap size.");
+    NewSize = bound_minus_alignment(NewSize, _initial_heap_byte_size);
+  }
+
+  // Now take the actual NewSize into account. We will silently increase NewSize
+  // if the user specified a smaller or unaligned value.
+  size_t bounded_new_size = bound_minus_alignment(NewSize, MaxHeapSize);
+  bounded_new_size = MAX2(smallest_new_size, (size_t)align_size_down(bounded_new_size, _gen_alignment));
+  if (bounded_new_size != NewSize) {
+    // Do not use FLAG_SET_ERGO to update NewSize here, since this will override
+    // if NewSize was set on the command line or not. This information is needed
+    // later when setting the initial and minimum young generation size.
+    NewSize = bounded_new_size;
+  }
+  _min_young_size = smallest_new_size;
+  _initial_young_size = NewSize;
+
+  if (!FLAG_IS_DEFAULT(MaxNewSize)) {
+    if (MaxNewSize >= MaxHeapSize) {
+      // Make sure there is room for an old generation
+      size_t smaller_max_new_size = MaxHeapSize - _gen_alignment;
+      if (FLAG_IS_CMDLINE(MaxNewSize)) {
+        warning("MaxNewSize (" SIZE_FORMAT "k) is equal to or greater than the entire "
+                "heap (" SIZE_FORMAT "k).  A new max generation size of " SIZE_FORMAT "k will be used.",
+                MaxNewSize/K, MaxHeapSize/K, smaller_max_new_size/K);
+      }
+      FLAG_SET_ERGO(size_t, MaxNewSize, smaller_max_new_size);
+      if (NewSize > MaxNewSize) {
+        FLAG_SET_ERGO(size_t, NewSize, MaxNewSize);
+        _initial_young_size = NewSize;
+      }
+    } else if (MaxNewSize < _initial_young_size) {
+      FLAG_SET_ERGO(size_t, MaxNewSize, _initial_young_size);
+    } else if (!is_size_aligned(MaxNewSize, _gen_alignment)) {
+      FLAG_SET_ERGO(size_t, MaxNewSize, align_size_down(MaxNewSize, _gen_alignment));
+    }
+    _max_young_size = MaxNewSize;
+  }
+
+  if (NewSize > MaxNewSize) {
+    // At this point this should only happen if the user specifies a large NewSize and/or
+    // a small (but not too small) MaxNewSize.
+    if (FLAG_IS_CMDLINE(MaxNewSize)) {
+      warning("NewSize (" SIZE_FORMAT "k) is greater than the MaxNewSize (" SIZE_FORMAT "k). "
+              "A new max generation size of " SIZE_FORMAT "k will be used.",
+              NewSize/K, MaxNewSize/K, NewSize/K);
+    }
+    FLAG_SET_ERGO(size_t, MaxNewSize, NewSize);
+    _max_young_size = MaxNewSize;
+  }
+
+  if (SurvivorRatio < 1 || NewRatio < 1) {
+    vm_exit_during_initialization("Invalid young gen ratio specified");
+  }
+
+  if (!is_size_aligned(OldSize, _gen_alignment)) {
+    // Setting OldSize directly to preserve information about the possible
+    // setting of OldSize on the command line.
+    OldSize = align_size_down(OldSize, _gen_alignment);
+  }
+
+  if (FLAG_IS_CMDLINE(OldSize) && FLAG_IS_DEFAULT(MaxHeapSize)) {
+    // NewRatio will be used later to set the young generation size so we use
+    // it to calculate how big the heap should be based on the requested OldSize
+    // and NewRatio.
+    assert(NewRatio > 0, "NewRatio should have been set up earlier");
+    size_t calculated_heapsize = (OldSize / NewRatio) * (NewRatio + 1);
+
+    calculated_heapsize = align_size_up(calculated_heapsize, _heap_alignment);
+    FLAG_SET_ERGO(size_t, MaxHeapSize, calculated_heapsize);
+    _max_heap_byte_size = MaxHeapSize;
+    FLAG_SET_ERGO(size_t, InitialHeapSize, calculated_heapsize);
+    _initial_heap_byte_size = InitialHeapSize;
+  }
+
+  // Adjust NewSize and OldSize or MaxHeapSize to match each other
+  if (NewSize + OldSize > MaxHeapSize) {
+    if (_max_heap_size_cmdline) {
+      // Somebody has set a maximum heap size with the intention that we should not
+      // exceed it. Adjust New/OldSize as necessary.
+      size_t calculated_size = NewSize + OldSize;
+      double shrink_factor = (double) MaxHeapSize / calculated_size;
+      size_t smaller_new_size = align_size_down((size_t)(NewSize * shrink_factor), _gen_alignment);
+      FLAG_SET_ERGO(size_t, NewSize, MAX2(young_gen_size_lower_bound(), smaller_new_size));
+      _initial_young_size = NewSize;
+
+      // OldSize is already aligned because above we aligned MaxHeapSize to
+      // _heap_alignment, and we just made sure that NewSize is aligned to
+      // _gen_alignment. In initialize_flags() we verified that _heap_alignment
+      // is a multiple of _gen_alignment.
+      FLAG_SET_ERGO(size_t, OldSize, MaxHeapSize - NewSize);
+    } else {
+      FLAG_SET_ERGO(size_t, MaxHeapSize, align_size_up(NewSize + OldSize, _heap_alignment));
+      _max_heap_byte_size = MaxHeapSize;
+    }
+  }
+
+  // Update NewSize, if possible, to avoid sizing the young gen too small when only
+  // OldSize is set on the command line.
+  if (FLAG_IS_CMDLINE(OldSize) && !FLAG_IS_CMDLINE(NewSize)) {
+    if (OldSize < _initial_heap_byte_size) {
+      size_t new_size = _initial_heap_byte_size - OldSize;
+      // Need to compare against the flag value for max since _max_young_size
+      // might not have been set yet.
+      if (new_size >= _min_young_size && new_size <= MaxNewSize) {
+        FLAG_SET_ERGO(size_t, NewSize, new_size);
+        _initial_young_size = NewSize;
+      }
+    }
+  }
+
+  always_do_update_barrier = UseConcMarkSweepGC;
+
+  DEBUG_ONLY(GenCollectorPolicy::assert_flags();)
+}
+
+// Values set on the command line win over any ergonomically
+// set command line parameters.
+// Ergonomic choice of parameters are done before this
+// method is called.  Values for command line parameters such as NewSize
+// and MaxNewSize feed those ergonomic choices into this method.
+// This method makes the final generation sizings consistent with
+// themselves and with overall heap sizings.
+// In the absence of explicitly set command line flags, policies
+// such as the use of NewRatio are used to size the generation.
+
+// Minimum sizes of the generations may be different than
+// the initial sizes.  An inconsistency is permitted here
+// in the total size that can be specified explicitly by
+// command line specification of OldSize and NewSize and
+// also a command line specification of -Xms.  Issue a warning
+// but allow the values to pass.
+void GenCollectorPolicy::initialize_size_info() {
+  CollectorPolicy::initialize_size_info();
+
+  _initial_young_size = NewSize;
+  _max_young_size = MaxNewSize;
+  _initial_old_size = OldSize;
+
+  // Determine maximum size of the young generation.
+
+  if (FLAG_IS_DEFAULT(MaxNewSize)) {
+    _max_young_size = scale_by_NewRatio_aligned(_max_heap_byte_size);
+    // Bound the maximum size by NewSize below (since it historically
+    // would have been NewSize and because the NewRatio calculation could
+    // yield a size that is too small) and bound it by MaxNewSize above.
+    // Ergonomics plays here by previously calculating the desired
+    // NewSize and MaxNewSize.
+    _max_young_size = MIN2(MAX2(_max_young_size, _initial_young_size), MaxNewSize);
+  }
+
+  // Given the maximum young size, determine the initial and
+  // minimum young sizes.
+
+  if (_max_heap_byte_size == _initial_heap_byte_size) {
+    // The maximum and initial heap sizes are the same so the generation's
+    // initial size must be the same as it maximum size. Use NewSize as the
+    // size if set on command line.
+    _max_young_size = FLAG_IS_CMDLINE(NewSize) ? NewSize : _max_young_size;
+    _initial_young_size = _max_young_size;
+
+    // Also update the minimum size if min == initial == max.
+    if (_max_heap_byte_size == _min_heap_byte_size) {
+      _min_young_size = _max_young_size;
+    }
+  } else {
+    if (FLAG_IS_CMDLINE(NewSize)) {
+      // If NewSize is set on the command line, we should use it as
+      // the initial size, but make sure it is within the heap bounds.
+      _initial_young_size =
+        MIN2(_max_young_size, bound_minus_alignment(NewSize, _initial_heap_byte_size));
+      _min_young_size = bound_minus_alignment(_initial_young_size, _min_heap_byte_size);
+    } else {
+      // For the case where NewSize is not set on the command line, use
+      // NewRatio to size the initial generation size. Use the current
+      // NewSize as the floor, because if NewRatio is overly large, the resulting
+      // size can be too small.
+      _initial_young_size =
+        MIN2(_max_young_size, MAX2(scale_by_NewRatio_aligned(_initial_heap_byte_size), NewSize));
+    }
+  }
+
+  if (PrintGCDetails && Verbose) {
+    gclog_or_tty->print_cr("1: Minimum young " SIZE_FORMAT "  Initial young "
+      SIZE_FORMAT "  Maximum young " SIZE_FORMAT,
+      _min_young_size, _initial_young_size, _max_young_size);
+  }
+
+  // At this point the minimum, initial and maximum sizes
+  // of the overall heap and of the young generation have been determined.
+  // The maximum old size can be determined from the maximum young
+  // and maximum heap size since no explicit flags exist
+  // for setting the old generation maximum.
+  _max_old_size = MAX2(_max_heap_byte_size - _max_young_size, _gen_alignment);
+
+  // If no explicit command line flag has been set for the
+  // old generation size, use what is left.
+  if (!FLAG_IS_CMDLINE(OldSize)) {
+    // The user has not specified any value but the ergonomics
+    // may have chosen a value (which may or may not be consistent
+    // with the overall heap size).  In either case make
+    // the minimum, maximum and initial sizes consistent
+    // with the young sizes and the overall heap sizes.
+    _min_old_size = _gen_alignment;
+    _initial_old_size = MIN2(_max_old_size, MAX2(_initial_heap_byte_size - _initial_young_size, _min_old_size));
+    // _max_old_size has already been made consistent above.
+  } else {
+    // OldSize has been explicitly set on the command line. Use it
+    // for the initial size but make sure the minimum allow a young
+    // generation to fit as well.
+    // If the user has explicitly set an OldSize that is inconsistent
+    // with other command line flags, issue a warning.
+    // The generation minimums and the overall heap minimum should
+    // be within one generation alignment.
+    if (_initial_old_size > _max_old_size) {
+      warning("Inconsistency between maximum heap size and maximum "
+          "generation sizes: using maximum heap = " SIZE_FORMAT
+          " -XX:OldSize flag is being ignored",
+          _max_heap_byte_size);
+      _initial_old_size = _max_old_size;
+    }
+
+    _min_old_size = MIN2(_initial_old_size, _min_heap_byte_size - _min_young_size);
+  }
+
+  // The initial generation sizes should match the initial heap size,
+  // if not issue a warning and resize the generations. This behavior
+  // differs from JDK8 where the generation sizes have higher priority
+  // than the initial heap size.
+  if ((_initial_old_size + _initial_young_size) != _initial_heap_byte_size) {
+    warning("Inconsistency between generation sizes and heap size, resizing "
+            "the generations to fit the heap.");
+
+    size_t desired_young_size = _initial_heap_byte_size - _initial_old_size;
+    if (_initial_heap_byte_size < _initial_old_size) {
+      // Old want all memory, use minimum for young and rest for old
+      _initial_young_size = _min_young_size;
+      _initial_old_size = _initial_heap_byte_size - _min_young_size;
+    } else if (desired_young_size > _max_young_size) {
+      // Need to increase both young and old generation
+      _initial_young_size = _max_young_size;
+      _initial_old_size = _initial_heap_byte_size - _max_young_size;
+    } else if (desired_young_size < _min_young_size) {
+      // Need to decrease both young and old generation
+      _initial_young_size = _min_young_size;
+      _initial_old_size = _initial_heap_byte_size - _min_young_size;
+    } else {
+      // The young generation boundaries allow us to only update the
+      // young generation.
+      _initial_young_size = desired_young_size;
+    }
+
+    if (PrintGCDetails && Verbose) {
+      gclog_or_tty->print_cr("2: Minimum young " SIZE_FORMAT "  Initial young "
+        SIZE_FORMAT "  Maximum young " SIZE_FORMAT,
+        _min_young_size, _initial_young_size, _max_young_size);
+    }
+  }
+
+  // Write back to flags if necessary.
+  if (NewSize != _initial_young_size) {
+    FLAG_SET_ERGO(size_t, NewSize, _initial_young_size);
+  }
+
+  if (MaxNewSize != _max_young_size) {
+    FLAG_SET_ERGO(size_t, MaxNewSize, _max_young_size);
+  }
+
+  if (OldSize != _initial_old_size) {
+    FLAG_SET_ERGO(size_t, OldSize, _initial_old_size);
+  }
+
+  if (PrintGCDetails && Verbose) {
+    gclog_or_tty->print_cr("Minimum old " SIZE_FORMAT "  Initial old "
+      SIZE_FORMAT "  Maximum old " SIZE_FORMAT,
+      _min_old_size, _initial_old_size, _max_old_size);
+  }
+
+  DEBUG_ONLY(GenCollectorPolicy::assert_size_info();)
+}
+
+HeapWord* GenCollectorPolicy::mem_allocate_work(size_t size,
+                                        bool is_tlab,
+                                        bool* gc_overhead_limit_was_exceeded) {
+  GenCollectedHeap *gch = GenCollectedHeap::heap();
+
+  debug_only(gch->check_for_valid_allocation_state());
+  assert(gch->no_gc_in_progress(), "Allocation during gc not allowed");
+
+  // In general gc_overhead_limit_was_exceeded should be false so
+  // set it so here and reset it to true only if the gc time
+  // limit is being exceeded as checked below.
+  *gc_overhead_limit_was_exceeded = false;
+
+  HeapWord* result = NULL;
+
+  // Loop until the allocation is satisfied, or unsatisfied after GC.
+  for (uint try_count = 1, gclocker_stalled_count = 0; /* return or throw */; try_count += 1) {
+    HandleMark hm; // Discard any handles allocated in each iteration.
+
+    // First allocation attempt is lock-free.
+    Generation *young = gch->young_gen();
+    assert(young->supports_inline_contig_alloc(),
+      "Otherwise, must do alloc within heap lock");
+    if (young->should_allocate(size, is_tlab)) {
+      result = young->par_allocate(size, is_tlab);
+      if (result != NULL) {
+        assert(gch->is_in_reserved(result), "result not in heap");
+        return result;
+      }
+    }
+    uint gc_count_before;  // Read inside the Heap_lock locked region.
+    {
+      MutexLocker ml(Heap_lock);
+      if (PrintGC && Verbose) {
+        gclog_or_tty->print_cr("GenCollectorPolicy::mem_allocate_work:"
+                               " attempting locked slow path allocation");
+      }
+      // Note that only large objects get a shot at being
+      // allocated in later generations.
+      bool first_only = ! should_try_older_generation_allocation(size);
+
+      result = gch->attempt_allocation(size, is_tlab, first_only);
+      if (result != NULL) {
+        assert(gch->is_in_reserved(result), "result not in heap");
+        return result;
+      }
+
+      if (GC_locker::is_active_and_needs_gc()) {
+        if (is_tlab) {
+          return NULL;  // Caller will retry allocating individual object.
+        }
+        if (!gch->is_maximal_no_gc()) {
+          // Try and expand heap to satisfy request.
+          result = expand_heap_and_allocate(size, is_tlab);
+          // Result could be null if we are out of space.
+          if (result != NULL) {
+            return result;
+          }
+        }
+
+        if (gclocker_stalled_count > GCLockerRetryAllocationCount) {
+          return NULL; // We didn't get to do a GC and we didn't get any memory.
+        }
+
+        // If this thread is not in a jni critical section, we stall
+        // the requestor until the critical section has cleared and
+        // GC allowed. When the critical section clears, a GC is
+        // initiated by the last thread exiting the critical section; so
+        // we retry the allocation sequence from the beginning of the loop,
+        // rather than causing more, now probably unnecessary, GC attempts.
+        JavaThread* jthr = JavaThread::current();
+        if (!jthr->in_critical()) {
+          MutexUnlocker mul(Heap_lock);
+          // Wait for JNI critical section to be exited
+          GC_locker::stall_until_clear();
+          gclocker_stalled_count += 1;
+          continue;
+        } else {
+          if (CheckJNICalls) {
+            fatal("Possible deadlock due to allocating while"
+                  " in jni critical section");
+          }
+          return NULL;
+        }
+      }
+
+      // Read the gc count while the heap lock is held.
+      gc_count_before = gch->total_collections();
+    }
+
+    VM_GenCollectForAllocation op(size, is_tlab, gc_count_before);
+    VMThread::execute(&op);
+    if (op.prologue_succeeded()) {
+      result = op.result();
+      if (op.gc_locked()) {
+         assert(result == NULL, "must be NULL if gc_locked() is true");
+         continue;  // Retry and/or stall as necessary.
+      }
+
+      // Allocation has failed and a collection
+      // has been done.  If the gc time limit was exceeded the
+      // this time, return NULL so that an out-of-memory
+      // will be thrown.  Clear gc_overhead_limit_exceeded
+      // so that the overhead exceeded does not persist.
+
+      const bool limit_exceeded = size_policy()->gc_overhead_limit_exceeded();
+      const bool softrefs_clear = all_soft_refs_clear();
+
+      if (limit_exceeded && softrefs_clear) {
+        *gc_overhead_limit_was_exceeded = true;
+        size_policy()->set_gc_overhead_limit_exceeded(false);
+        if (op.result() != NULL) {
+          CollectedHeap::fill_with_object(op.result(), size);
+        }
+        return NULL;
+      }
+      assert(result == NULL || gch->is_in_reserved(result),
+             "result not in heap");
+      return result;
+    }
+
+    // Give a warning if we seem to be looping forever.
+    if ((QueuedAllocationWarningCount > 0) &&
+        (try_count % QueuedAllocationWarningCount == 0)) {
+          warning("GenCollectorPolicy::mem_allocate_work retries %d times \n\t"
+                  " size=" SIZE_FORMAT " %s", try_count, size, is_tlab ? "(TLAB)" : "");
+    }
+  }
+}
+
+HeapWord* GenCollectorPolicy::expand_heap_and_allocate(size_t size,
+                                                       bool   is_tlab) {
+  GenCollectedHeap *gch = GenCollectedHeap::heap();
+  HeapWord* result = NULL;
+  Generation *old = gch->old_gen();
+  if (old->should_allocate(size, is_tlab)) {
+    result = old->expand_and_allocate(size, is_tlab);
+  }
+  if (result == NULL) {
+    Generation *young = gch->young_gen();
+    if (young->should_allocate(size, is_tlab)) {
+      result = young->expand_and_allocate(size, is_tlab);
+    }
+  }
+  assert(result == NULL || gch->is_in_reserved(result), "result not in heap");
+  return result;
+}
+
+HeapWord* GenCollectorPolicy::satisfy_failed_allocation(size_t size,
+                                                        bool   is_tlab) {
+  GenCollectedHeap *gch = GenCollectedHeap::heap();
+  GCCauseSetter x(gch, GCCause::_allocation_failure);
+  HeapWord* result = NULL;
+
+  assert(size != 0, "Precondition violated");
+  if (GC_locker::is_active_and_needs_gc()) {
+    // GC locker is active; instead of a collection we will attempt
+    // to expand the heap, if there's room for expansion.
+    if (!gch->is_maximal_no_gc()) {
+      result = expand_heap_and_allocate(size, is_tlab);
+    }
+    return result;   // Could be null if we are out of space.
+  } else if (!gch->incremental_collection_will_fail(false /* don't consult_young */)) {
+    // Do an incremental collection.
+    gch->do_collection(false            /* full */,
+                       false            /* clear_all_soft_refs */,
+                       size             /* size */,
+                       is_tlab          /* is_tlab */,
+                       number_of_generations() - 1 /* max_level */);
+  } else {
+    if (Verbose && PrintGCDetails) {
+      gclog_or_tty->print(" :: Trying full because partial may fail :: ");
+    }
+    // Try a full collection; see delta for bug id 6266275
+    // for the original code and why this has been simplified
+    // with from-space allocation criteria modified and
+    // such allocation moved out of the safepoint path.
+    gch->do_collection(true             /* full */,
+                       false            /* clear_all_soft_refs */,
+                       size             /* size */,
+                       is_tlab          /* is_tlab */,
+                       number_of_generations() - 1 /* max_level */);
+  }
+
+  result = gch->attempt_allocation(size, is_tlab, false /*first_only*/);
+
+  if (result != NULL) {
+    assert(gch->is_in_reserved(result), "result not in heap");
+    return result;
+  }
+
+  // OK, collection failed, try expansion.
+  result = expand_heap_and_allocate(size, is_tlab);
+  if (result != NULL) {
+    return result;
+  }
+
+  // If we reach this point, we're really out of memory. Try every trick
+  // we can to reclaim memory. Force collection of soft references. Force
+  // a complete compaction of the heap. Any additional methods for finding
+  // free memory should be here, especially if they are expensive. If this
+  // attempt fails, an OOM exception will be thrown.
+  {
+    UIntFlagSetting flag_change(MarkSweepAlwaysCompactCount, 1); // Make sure the heap is fully compacted
+
+    gch->do_collection(true             /* full */,
+                       true             /* clear_all_soft_refs */,
+                       size             /* size */,
+                       is_tlab          /* is_tlab */,
+                       number_of_generations() - 1 /* max_level */);
+  }
+
+  result = gch->attempt_allocation(size, is_tlab, false /* first_only */);
+  if (result != NULL) {
+    assert(gch->is_in_reserved(result), "result not in heap");
+    return result;
+  }
+
+  assert(!should_clear_all_soft_refs(),
+    "Flag should have been handled and cleared prior to this point");
+
+  // What else?  We might try synchronous finalization later.  If the total
+  // space available is large enough for the allocation, then a more
+  // complete compaction phase than we've tried so far might be
+  // appropriate.
+  return NULL;
+}
+
+MetaWord* CollectorPolicy::satisfy_failed_metadata_allocation(
+                                                 ClassLoaderData* loader_data,
+                                                 size_t word_size,
+                                                 Metaspace::MetadataType mdtype) {
+  uint loop_count = 0;
+  uint gc_count = 0;
+  uint full_gc_count = 0;
+
+  assert(!Heap_lock->owned_by_self(), "Should not be holding the Heap_lock");
+
+  do {
+    MetaWord* result = loader_data->metaspace_non_null()->allocate(word_size, mdtype);
+    if (result != NULL) {
+      return result;
+    }
+
+    if (GC_locker::is_active_and_needs_gc()) {
+      // If the GC_locker is active, just expand and allocate.
+      // If that does not succeed, wait if this thread is not
+      // in a critical section itself.
+      result =
+        loader_data->metaspace_non_null()->expand_and_allocate(word_size,
+                                                               mdtype);
+      if (result != NULL) {
+        return result;
+      }
+      JavaThread* jthr = JavaThread::current();
+      if (!jthr->in_critical()) {
+        // Wait for JNI critical section to be exited
+        GC_locker::stall_until_clear();
+        // The GC invoked by the last thread leaving the critical
+        // section will be a young collection and a full collection
+        // is (currently) needed for unloading classes so continue
+        // to the next iteration to get a full GC.
+        continue;
+      } else {
+        if (CheckJNICalls) {
+          fatal("Possible deadlock due to allocating while"
+                " in jni critical section");
+        }
+        return NULL;
+      }
+    }
+
+    {  // Need lock to get self consistent gc_count's
+      MutexLocker ml(Heap_lock);
+      gc_count      = Universe::heap()->total_collections();
+      full_gc_count = Universe::heap()->total_full_collections();
+    }
+
+    // Generate a VM operation
+    VM_CollectForMetadataAllocation op(loader_data,
+                                       word_size,
+                                       mdtype,
+                                       gc_count,
+                                       full_gc_count,
+                                       GCCause::_metadata_GC_threshold);
+    VMThread::execute(&op);
+
+    // If GC was locked out, try again. Check before checking success because the
+    // prologue could have succeeded and the GC still have been locked out.
+    if (op.gc_locked()) {
+      continue;
+    }
+
+    if (op.prologue_succeeded()) {
+      return op.result();
+    }
+    loop_count++;
+    if ((QueuedAllocationWarningCount > 0) &&
+        (loop_count % QueuedAllocationWarningCount == 0)) {
+      warning("satisfy_failed_metadata_allocation() retries %d times \n\t"
+              " size=" SIZE_FORMAT, loop_count, word_size);
+    }
+  } while (true);  // Until a GC is done
+}
+
+// Return true if any of the following is true:
+// . the allocation won't fit into the current young gen heap
+// . gc locker is occupied (jni critical section)
+// . heap memory is tight -- the most recent previous collection
+//   was a full collection because a partial collection (would
+//   have) failed and is likely to fail again
+bool GenCollectorPolicy::should_try_older_generation_allocation(
+        size_t word_size) const {
+  GenCollectedHeap* gch = GenCollectedHeap::heap();
+  size_t young_capacity = gch->young_gen()->capacity_before_gc();
+  return    (word_size > heap_word_size(young_capacity))
+         || GC_locker::is_active_and_needs_gc()
+         || gch->incremental_collection_failed();
+}
+
+
+//
+// MarkSweepPolicy methods
+//
+
+void MarkSweepPolicy::initialize_alignments() {
+  _space_alignment = _gen_alignment = (size_t)Generation::GenGrain;
+  _heap_alignment = compute_heap_alignment();
+}
+
+void MarkSweepPolicy::initialize_generations() {
+  _young_gen_spec = new GenerationSpec(Generation::DefNew, _initial_young_size, _max_young_size, _gen_alignment);
+  _old_gen_spec   = new GenerationSpec(Generation::MarkSweepCompact, _initial_old_size, _max_old_size, _gen_alignment);
+}
+
+void MarkSweepPolicy::initialize_gc_policy_counters() {
+  // Initialize the policy counters - 2 collectors, 3 generations.
+  _gc_policy_counters = new GCPolicyCounters("Copy:MSC", 2, 3);
+}
+
+/////////////// Unit tests ///////////////
+
+#ifndef PRODUCT
+// Testing that the NewSize flag is handled correct is hard because it
+// depends on so many other configurable variables. This test only tries to
+// verify that there are some basic rules for NewSize honored by the policies.
+class TestGenCollectorPolicy {
+public:
+  static void test_new_size() {
+    size_t flag_value;
+
+    save_flags();
+
+    // If NewSize is set on the command line, it should be used
+    // for both min and initial young size if less than min heap.
+    flag_value = 20 * M;
+    set_basic_flag_values();
+    FLAG_SET_CMDLINE(size_t, NewSize, flag_value);
+    verify_young_min(flag_value);
+
+    set_basic_flag_values();
+    FLAG_SET_CMDLINE(size_t, NewSize, flag_value);
+    verify_young_initial(flag_value);
+
+    // If NewSize is set on command line, but is larger than the min
+    // heap size, it should only be used for initial young size.
+    flag_value = 80 * M;
+    set_basic_flag_values();
+    FLAG_SET_CMDLINE(size_t, NewSize, flag_value);
+    verify_young_initial(flag_value);
+
+    // If NewSize has been ergonomically set, the collector policy
+    // should use it for min but calculate the initial young size
+    // using NewRatio.
+    flag_value = 20 * M;
+    set_basic_flag_values();
+    FLAG_SET_ERGO(size_t, NewSize, flag_value);
+    verify_young_min(flag_value);
+
+    set_basic_flag_values();
+    FLAG_SET_ERGO(size_t, NewSize, flag_value);
+    verify_scaled_young_initial(InitialHeapSize);
+
+    restore_flags();
+  }
+
+  static void test_old_size() {
+    size_t flag_value;
+    size_t heap_alignment = CollectorPolicy::compute_heap_alignment();
+
+    save_flags();
+
+    // If OldSize is set on the command line, it should be used
+    // for both min and initial old size if less than min heap.
+    flag_value = 20 * M;
+    set_basic_flag_values();
+    FLAG_SET_CMDLINE(size_t, OldSize, flag_value);
+    verify_old_min(flag_value);
+
+    set_basic_flag_values();
+    FLAG_SET_CMDLINE(size_t, OldSize, flag_value);
+    // Calculate what we expect the flag to be.
+    size_t expected_old_initial = align_size_up(InitialHeapSize, heap_alignment) - MaxNewSize;
+    verify_old_initial(expected_old_initial);
+
+    // If MaxNewSize is large, the maximum OldSize will be less than
+    // what's requested on the command line and it should be reset
+    // ergonomically.
+    // We intentionally set MaxNewSize + OldSize > MaxHeapSize (see over_size).
+    flag_value = 30 * M;
+    set_basic_flag_values();
+    FLAG_SET_CMDLINE(size_t, OldSize, flag_value);
+    size_t over_size = 20*M;
+    size_t new_size_value = align_size_up(MaxHeapSize, heap_alignment) - flag_value + over_size;
+    FLAG_SET_CMDLINE(size_t, MaxNewSize, new_size_value);
+    // Calculate what we expect the flag to be.
+    expected_old_initial = align_size_up(MaxHeapSize, heap_alignment) - MaxNewSize;
+    verify_old_initial(expected_old_initial);
+    restore_flags();
+  }
+
+  static void verify_young_min(size_t expected) {
+    MarkSweepPolicy msp;
+    msp.initialize_all();
+
+    assert(msp.min_young_size() <= expected, err_msg("%zu  > %zu", msp.min_young_size(), expected));
+  }
+
+  static void verify_young_initial(size_t expected) {
+    MarkSweepPolicy msp;
+    msp.initialize_all();
+
+    assert(msp.initial_young_size() == expected, err_msg("%zu != %zu", msp.initial_young_size(), expected));
+  }
+
+  static void verify_scaled_young_initial(size_t initial_heap_size) {
+    MarkSweepPolicy msp;
+    msp.initialize_all();
+
+    if (InitialHeapSize > initial_heap_size) {
+      // InitialHeapSize was adapted by msp.initialize_all, e.g. due to alignment
+      // caused by 64K page size.
+      initial_heap_size = InitialHeapSize;
+    }
+
+    size_t expected = msp.scale_by_NewRatio_aligned(initial_heap_size);
+    assert(msp.initial_young_size() == expected, err_msg("%zu != %zu", msp.initial_young_size(), expected));
+    assert(FLAG_IS_ERGO(NewSize) && NewSize == expected,
+        err_msg("NewSize should have been set ergonomically to %zu, but was %zu", expected, NewSize));
+  }
+
+  static void verify_old_min(size_t expected) {
+    MarkSweepPolicy msp;
+    msp.initialize_all();
+
+    assert(msp.min_old_size() <= expected, err_msg("%zu  > %zu", msp.min_old_size(), expected));
+  }
+
+  static void verify_old_initial(size_t expected) {
+    MarkSweepPolicy msp;
+    msp.initialize_all();
+
+    assert(msp.initial_old_size() == expected, err_msg("%zu != %zu", msp.initial_old_size(), expected));
+  }
+
+
+private:
+  static size_t original_InitialHeapSize;
+  static size_t original_MaxHeapSize;
+  static size_t original_MaxNewSize;
+  static size_t original_MinHeapDeltaBytes;
+  static size_t original_NewSize;
+  static size_t original_OldSize;
+
+  static void set_basic_flag_values() {
+    FLAG_SET_ERGO(size_t, MaxHeapSize, 180 * M);
+    FLAG_SET_ERGO(size_t, InitialHeapSize, 100 * M);
+    FLAG_SET_ERGO(size_t, OldSize, 4 * M);
+    FLAG_SET_ERGO(size_t, NewSize, 1 * M);
+    FLAG_SET_ERGO(size_t, MaxNewSize, 80 * M);
+    Arguments::set_min_heap_size(40 * M);
+  }
+
+  static void save_flags() {
+    original_InitialHeapSize   = InitialHeapSize;
+    original_MaxHeapSize       = MaxHeapSize;
+    original_MaxNewSize        = MaxNewSize;
+    original_MinHeapDeltaBytes = MinHeapDeltaBytes;
+    original_NewSize           = NewSize;
+    original_OldSize           = OldSize;
+  }
+
+  static void restore_flags() {
+    InitialHeapSize   = original_InitialHeapSize;
+    MaxHeapSize       = original_MaxHeapSize;
+    MaxNewSize        = original_MaxNewSize;
+    MinHeapDeltaBytes = original_MinHeapDeltaBytes;
+    NewSize           = original_NewSize;
+    OldSize           = original_OldSize;
+  }
+};
+
+size_t TestGenCollectorPolicy::original_InitialHeapSize   = 0;
+size_t TestGenCollectorPolicy::original_MaxHeapSize       = 0;
+size_t TestGenCollectorPolicy::original_MaxNewSize        = 0;
+size_t TestGenCollectorPolicy::original_MinHeapDeltaBytes = 0;
+size_t TestGenCollectorPolicy::original_NewSize           = 0;
+size_t TestGenCollectorPolicy::original_OldSize           = 0;
+
+void TestNewSize_test() {
+  TestGenCollectorPolicy::test_new_size();
+}
+
+void TestOldSize_test() {
+  TestGenCollectorPolicy::test_old_size();
+}
+
+#endif