8042298: Remove the names gen0 and gen1 from the GC code
authorjwilhelm
Fri, 02 May 2014 02:11:34 +0200
changeset 24941 4ebbe176a7b1
parent 24940 c2b4c8e32c2f
child 24942 4ac6e5d63db6
8042298: Remove the names gen0 and gen1 from the GC code Summary: Renamed gen0 and gen1 to young and old throughout the GC code. Reviewed-by: sjohanss, jcoomes
hotspot/src/share/vm/gc_implementation/concurrentMarkSweep/cmsAdaptiveSizePolicy.cpp
hotspot/src/share/vm/gc_implementation/concurrentMarkSweep/cmsCollectorPolicy.cpp
hotspot/src/share/vm/gc_implementation/concurrentMarkSweep/concurrentMarkSweepGeneration.cpp
hotspot/src/share/vm/gc_implementation/concurrentMarkSweep/concurrentMarkSweepGeneration.hpp
hotspot/src/share/vm/gc_implementation/g1/g1CollectedHeap.cpp
hotspot/src/share/vm/gc_implementation/g1/g1CollectorPolicy.cpp
hotspot/src/share/vm/gc_implementation/g1/g1CollectorPolicy.hpp
hotspot/src/share/vm/gc_implementation/parallelScavenge/adjoiningGenerations.cpp
hotspot/src/share/vm/gc_implementation/parallelScavenge/generationSizer.cpp
hotspot/src/share/vm/gc_implementation/parallelScavenge/parallelScavengeHeap.cpp
hotspot/src/share/vm/gc_implementation/parallelScavenge/psMarkSweep.cpp
hotspot/src/share/vm/gc_implementation/parallelScavenge/psParallelCompact.cpp
hotspot/src/share/vm/gc_implementation/parallelScavenge/psScavenge.cpp
hotspot/src/share/vm/memory/collectorPolicy.cpp
hotspot/src/share/vm/memory/collectorPolicy.hpp
hotspot/src/share/vm/memory/genCollectedHeap.cpp
hotspot/src/share/vm/memory/tenuredGeneration.hpp
hotspot/src/share/vm/runtime/arguments.cpp
hotspot/src/share/vm/runtime/globals.hpp
--- a/hotspot/src/share/vm/gc_implementation/concurrentMarkSweep/cmsAdaptiveSizePolicy.cpp	Wed Apr 30 02:41:00 2014 +0200
+++ b/hotspot/src/share/vm/gc_implementation/concurrentMarkSweep/cmsAdaptiveSizePolicy.cpp	Fri May 02 02:11:34 2014 +0200
@@ -1341,13 +1341,14 @@
 bool CMSAdaptiveSizePolicy::print_adaptive_size_policy_on(
                                                     outputStream* st) const {
 
-  if (!UseAdaptiveSizePolicy) return false;
+  if (!UseAdaptiveSizePolicy) {
+    return false;
+  }
 
   GenCollectedHeap* gch = GenCollectedHeap::heap();
-  Generation* gen0 = gch->get_gen(0);
-  DefNewGeneration* def_new = gen0->as_DefNewGeneration();
-  return
-    AdaptiveSizePolicy::print_adaptive_size_policy_on(
+  Generation* young = gch->get_gen(0);
+  DefNewGeneration* def_new = young->as_DefNewGeneration();
+  return AdaptiveSizePolicy::print_adaptive_size_policy_on(
                                          st,
                                          def_new->tenuring_threshold());
 }
--- a/hotspot/src/share/vm/gc_implementation/concurrentMarkSweep/cmsCollectorPolicy.cpp	Wed Apr 30 02:41:00 2014 +0200
+++ b/hotspot/src/share/vm/gc_implementation/concurrentMarkSweep/cmsCollectorPolicy.cpp	Fri May 02 02:11:34 2014 +0200
@@ -60,21 +60,21 @@
   if (UseParNewGC) {
     if (UseAdaptiveSizePolicy) {
       _generations[0] = new GenerationSpec(Generation::ASParNew,
-                                           _initial_gen0_size, _max_gen0_size);
+                                           _initial_young_size, _max_young_size);
     } else {
       _generations[0] = new GenerationSpec(Generation::ParNew,
-                                           _initial_gen0_size, _max_gen0_size);
+                                           _initial_young_size, _max_young_size);
     }
   } else {
     _generations[0] = new GenerationSpec(Generation::DefNew,
-                                         _initial_gen0_size, _max_gen0_size);
+                                         _initial_young_size, _max_young_size);
   }
   if (UseAdaptiveSizePolicy) {
     _generations[1] = new GenerationSpec(Generation::ASConcurrentMarkSweep,
-                            _initial_gen1_size, _max_gen1_size);
+                                         _initial_old_size, _max_old_size);
   } else {
     _generations[1] = new GenerationSpec(Generation::ConcurrentMarkSweep,
-                            _initial_gen1_size, _max_gen1_size);
+                                         _initial_old_size, _max_old_size);
   }
 
   if (_generations[0] == NULL || _generations[1] == NULL) {
--- a/hotspot/src/share/vm/gc_implementation/concurrentMarkSweep/concurrentMarkSweepGeneration.cpp	Wed Apr 30 02:41:00 2014 +0200
+++ b/hotspot/src/share/vm/gc_implementation/concurrentMarkSweep/concurrentMarkSweepGeneration.cpp	Fri May 02 02:11:34 2014 +0200
@@ -1138,8 +1138,8 @@
 
 void CMSCollector::icms_update_allocation_limits()
 {
-  Generation* gen0 = GenCollectedHeap::heap()->get_gen(0);
-  EdenSpace* eden = gen0->as_DefNewGeneration()->eden();
+  Generation* young = GenCollectedHeap::heap()->get_gen(0);
+  EdenSpace* eden = young->as_DefNewGeneration()->eden();
 
   const unsigned int duty_cycle = stats().icms_update_duty_cycle();
   if (CMSTraceIncrementalPacing) {
--- a/hotspot/src/share/vm/gc_implementation/concurrentMarkSweep/concurrentMarkSweepGeneration.hpp	Wed Apr 30 02:41:00 2014 +0200
+++ b/hotspot/src/share/vm/gc_implementation/concurrentMarkSweep/concurrentMarkSweepGeneration.hpp	Fri May 02 02:11:34 2014 +0200
@@ -1193,10 +1193,9 @@
   // Does a "full" (forced) collection invoked on this generation collect
   // all younger generations as well? Note that the second conjunct is a
   // hack to allow the collection of the younger gen first if the flag is
-  // set. This is better than using th policy's should_collect_gen0_first()
-  // since that causes us to do an extra unnecessary pair of restart-&-stop-world.
+  // set.
   virtual bool full_collects_younger_generations() const {
-    return UseCMSCompactAtFullCollection && !CollectGen0First;
+    return UseCMSCompactAtFullCollection && !ScavengeBeforeFullGC;
   }
 
   void space_iterate(SpaceClosure* blk, bool usedOnly = false);
--- a/hotspot/src/share/vm/gc_implementation/g1/g1CollectedHeap.cpp	Wed Apr 30 02:41:00 2014 +0200
+++ b/hotspot/src/share/vm/gc_implementation/g1/g1CollectedHeap.cpp	Fri May 02 02:11:34 2014 +0200
@@ -3622,7 +3622,7 @@
 
 void G1CollectedHeap::print_tracing_info() const {
   // We'll overload this to mean "trace GC pause statistics."
-  if (TraceGen0Time || TraceGen1Time) {
+  if (TraceYoungGenTime || TraceOldGenTime) {
     // The "G1CollectorPolicy" is keeping track of these stats, so delegate
     // to that.
     g1_policy()->print_tracing_info();
--- a/hotspot/src/share/vm/gc_implementation/g1/g1CollectorPolicy.cpp	Wed Apr 30 02:41:00 2014 +0200
+++ b/hotspot/src/share/vm/gc_implementation/g1/g1CollectorPolicy.cpp	Fri May 02 02:11:34 2014 +0200
@@ -809,7 +809,7 @@
   double full_gc_time_sec = end_sec - _full_collection_start_sec;
   double full_gc_time_ms = full_gc_time_sec * 1000.0;
 
-  _trace_gen1_time_data.record_full_collection(full_gc_time_ms);
+  _trace_old_gen_time_data.record_full_collection(full_gc_time_ms);
 
   update_recent_gc_times(end_sec, full_gc_time_ms);
 
@@ -851,7 +851,7 @@
                  _g1->used(), _g1->recalculate_used()));
 
   double s_w_t_ms = (start_time_sec - _stop_world_start) * 1000.0;
-  _trace_gen0_time_data.record_start_collection(s_w_t_ms);
+  _trace_young_gen_time_data.record_start_collection(s_w_t_ms);
   _stop_world_start = 0.0;
 
   record_heap_size_info_at_start(false /* full */);
@@ -906,7 +906,7 @@
 void G1CollectorPolicy::record_concurrent_pause() {
   if (_stop_world_start > 0.0) {
     double yield_ms = (os::elapsedTime() - _stop_world_start) * 1000.0;
-    _trace_gen0_time_data.record_yield_time(yield_ms);
+    _trace_young_gen_time_data.record_yield_time(yield_ms);
   }
 }
 
@@ -993,7 +993,7 @@
   evacuation_info.set_bytes_copied(_bytes_copied_during_gc);
 
   if (update_stats) {
-    _trace_gen0_time_data.record_end_collection(pause_time_ms, phase_times());
+    _trace_young_gen_time_data.record_end_collection(pause_time_ms, phase_times());
     // this is where we update the allocation rate of the application
     double app_time_ms =
       (phase_times()->cur_collection_start_sec() * 1000.0 - _prev_collection_pause_end_ms);
@@ -1415,8 +1415,8 @@
 }
 
 void G1CollectorPolicy::print_tracing_info() const {
-  _trace_gen0_time_data.print();
-  _trace_gen1_time_data.print();
+  _trace_young_gen_time_data.print();
+  _trace_old_gen_time_data.print();
 }
 
 void G1CollectorPolicy::print_yg_surv_rate_info() const {
@@ -1973,9 +1973,9 @@
   _last_gc_was_young = gcs_are_young() ? true : false;
 
   if (_last_gc_was_young) {
-    _trace_gen0_time_data.increment_young_collection_count();
+    _trace_young_gen_time_data.increment_young_collection_count();
   } else {
-    _trace_gen0_time_data.increment_mixed_collection_count();
+    _trace_young_gen_time_data.increment_mixed_collection_count();
   }
 
   // The young list is laid with the survivor regions from the previous
@@ -2156,20 +2156,20 @@
   evacuation_info.set_collectionset_regions(cset_region_length());
 }
 
-void TraceGen0TimeData::record_start_collection(double time_to_stop_the_world_ms) {
-  if(TraceGen0Time) {
+void TraceYoungGenTimeData::record_start_collection(double time_to_stop_the_world_ms) {
+  if(TraceYoungGenTime) {
     _all_stop_world_times_ms.add(time_to_stop_the_world_ms);
   }
 }
 
-void TraceGen0TimeData::record_yield_time(double yield_time_ms) {
-  if(TraceGen0Time) {
+void TraceYoungGenTimeData::record_yield_time(double yield_time_ms) {
+  if(TraceYoungGenTime) {
     _all_yield_times_ms.add(yield_time_ms);
   }
 }
 
-void TraceGen0TimeData::record_end_collection(double pause_time_ms, G1GCPhaseTimes* phase_times) {
-  if(TraceGen0Time) {
+void TraceYoungGenTimeData::record_end_collection(double pause_time_ms, G1GCPhaseTimes* phase_times) {
+  if(TraceYoungGenTime) {
     _total.add(pause_time_ms);
     _other.add(pause_time_ms - phase_times->accounted_time_ms());
     _root_region_scan_wait.add(phase_times->root_region_scan_wait_time_ms());
@@ -2194,34 +2194,34 @@
   }
 }
 
-void TraceGen0TimeData::increment_young_collection_count() {
-  if(TraceGen0Time) {
+void TraceYoungGenTimeData::increment_young_collection_count() {
+  if(TraceYoungGenTime) {
     ++_young_pause_num;
   }
 }
 
-void TraceGen0TimeData::increment_mixed_collection_count() {
-  if(TraceGen0Time) {
+void TraceYoungGenTimeData::increment_mixed_collection_count() {
+  if(TraceYoungGenTime) {
     ++_mixed_pause_num;
   }
 }
 
-void TraceGen0TimeData::print_summary(const char* str,
-                                      const NumberSeq* seq) const {
+void TraceYoungGenTimeData::print_summary(const char* str,
+                                          const NumberSeq* seq) const {
   double sum = seq->sum();
   gclog_or_tty->print_cr("%-27s = %8.2lf s (avg = %8.2lf ms)",
                 str, sum / 1000.0, seq->avg());
 }
 
-void TraceGen0TimeData::print_summary_sd(const char* str,
-                                         const NumberSeq* seq) const {
+void TraceYoungGenTimeData::print_summary_sd(const char* str,
+                                             const NumberSeq* seq) const {
   print_summary(str, seq);
   gclog_or_tty->print_cr("%+45s = %5d, std dev = %8.2lf ms, max = %8.2lf ms)",
                 "(num", seq->num(), seq->sd(), seq->maximum());
 }
 
-void TraceGen0TimeData::print() const {
-  if (!TraceGen0Time) {
+void TraceYoungGenTimeData::print() const {
+  if (!TraceYoungGenTime) {
     return;
   }
 
@@ -2258,14 +2258,14 @@
   print_summary_sd("   Yields", &_all_yield_times_ms);
 }
 
-void TraceGen1TimeData::record_full_collection(double full_gc_time_ms) {
-  if (TraceGen1Time) {
+void TraceOldGenTimeData::record_full_collection(double full_gc_time_ms) {
+  if (TraceOldGenTime) {
     _all_full_gc_times.add(full_gc_time_ms);
   }
 }
 
-void TraceGen1TimeData::print() const {
-  if (!TraceGen1Time) {
+void TraceOldGenTimeData::print() const {
+  if (!TraceOldGenTime) {
     return;
   }
 
--- a/hotspot/src/share/vm/gc_implementation/g1/g1CollectorPolicy.hpp	Wed Apr 30 02:41:00 2014 +0200
+++ b/hotspot/src/share/vm/gc_implementation/g1/g1CollectorPolicy.hpp	Fri May 02 02:11:34 2014 +0200
@@ -38,10 +38,10 @@
 class CollectionSetChooser;
 class G1GCPhaseTimes;
 
-// TraceGen0Time collects data on _both_ young and mixed evacuation pauses
+// TraceYoungGenTime collects data on _both_ young and mixed evacuation pauses
 // (the latter may contain non-young regions - i.e. regions that are
-// technically in Gen1) while TraceGen1Time collects data about full GCs.
-class TraceGen0TimeData : public CHeapObj<mtGC> {
+// technically in old) while TraceOldGenTime collects data about full GCs.
+class TraceYoungGenTimeData : public CHeapObj<mtGC> {
  private:
   unsigned  _young_pause_num;
   unsigned  _mixed_pause_num;
@@ -66,7 +66,7 @@
   void print_summary_sd(const char* str, const NumberSeq* seq) const;
 
 public:
-   TraceGen0TimeData() : _young_pause_num(0), _mixed_pause_num(0) {};
+   TraceYoungGenTimeData() : _young_pause_num(0), _mixed_pause_num(0) {};
   void record_start_collection(double time_to_stop_the_world_ms);
   void record_yield_time(double yield_time_ms);
   void record_end_collection(double pause_time_ms, G1GCPhaseTimes* phase_times);
@@ -75,7 +75,7 @@
   void print() const;
 };
 
-class TraceGen1TimeData : public CHeapObj<mtGC> {
+class TraceOldGenTimeData : public CHeapObj<mtGC> {
  private:
   NumberSeq _all_full_gc_times;
 
@@ -187,8 +187,8 @@
   TruncatedSeq* _concurrent_mark_remark_times_ms;
   TruncatedSeq* _concurrent_mark_cleanup_times_ms;
 
-  TraceGen0TimeData _trace_gen0_time_data;
-  TraceGen1TimeData _trace_gen1_time_data;
+  TraceYoungGenTimeData _trace_young_gen_time_data;
+  TraceOldGenTimeData   _trace_old_gen_time_data;
 
   double _stop_world_start;
 
@@ -202,20 +202,20 @@
   // locker is active. This should be >= _young_list_target_length;
   uint _young_list_max_length;
 
-  bool                  _last_gc_was_young;
+  bool _last_gc_was_young;
 
-  bool                  _during_marking;
-  bool                  _in_marking_window;
-  bool                  _in_marking_window_im;
+  bool _during_marking;
+  bool _in_marking_window;
+  bool _in_marking_window_im;
 
-  SurvRateGroup*        _short_lived_surv_rate_group;
-  SurvRateGroup*        _survivor_surv_rate_group;
+  SurvRateGroup* _short_lived_surv_rate_group;
+  SurvRateGroup* _survivor_surv_rate_group;
   // add here any more surv rate groups
 
-  double                _gc_overhead_perc;
+  double _gc_overhead_perc;
 
   double _reserve_factor;
-  uint _reserve_regions;
+  uint   _reserve_regions;
 
   bool during_marking() {
     return _during_marking;
--- a/hotspot/src/share/vm/gc_implementation/parallelScavenge/adjoiningGenerations.cpp	Wed Apr 30 02:41:00 2014 +0200
+++ b/hotspot/src/share/vm/gc_implementation/parallelScavenge/adjoiningGenerations.cpp	Fri May 02 02:11:34 2014 +0200
@@ -35,14 +35,14 @@
 AdjoiningGenerations::AdjoiningGenerations(ReservedSpace old_young_rs,
                                            GenerationSizer* policy,
                                            size_t alignment) :
-  _virtual_spaces(old_young_rs, policy->min_gen1_size(),
-                  policy->min_gen0_size(), alignment) {
-  size_t init_low_byte_size = policy->initial_gen1_size();
-  size_t min_low_byte_size = policy->min_gen1_size();
-  size_t max_low_byte_size = policy->max_gen1_size();
-  size_t init_high_byte_size = policy->initial_gen0_size();
-  size_t min_high_byte_size = policy->min_gen0_size();
-  size_t max_high_byte_size = policy->max_gen0_size();
+  _virtual_spaces(old_young_rs, policy->min_old_size(),
+                  policy->min_young_size(), alignment) {
+  size_t init_low_byte_size = policy->initial_old_size();
+  size_t min_low_byte_size = policy->min_old_size();
+  size_t max_low_byte_size = policy->max_old_size();
+  size_t init_high_byte_size = policy->initial_young_size();
+  size_t min_high_byte_size = policy->min_young_size();
+  size_t max_high_byte_size = policy->max_young_size();
 
   assert(min_low_byte_size <= init_low_byte_size &&
          init_low_byte_size <= max_low_byte_size, "Parameter check");
--- a/hotspot/src/share/vm/gc_implementation/parallelScavenge/generationSizer.cpp	Wed Apr 30 02:41:00 2014 +0200
+++ b/hotspot/src/share/vm/gc_implementation/parallelScavenge/generationSizer.cpp	Fri May 02 02:11:34 2014 +0200
@@ -32,8 +32,8 @@
                   SIZE_FORMAT "," SIZE_FORMAT " "
                   SIZE_FORMAT,
                   str,
-                  _min_gen1_size / K, _max_gen1_size / K,
-                  _min_gen0_size / K, _max_gen0_size / K,
+                  _min_old_size / K, _max_old_size / K,
+                  _min_young_size / K, _max_young_size / K,
                   _max_heap_byte_size / K);
   }
 }
--- a/hotspot/src/share/vm/gc_implementation/parallelScavenge/parallelScavengeHeap.cpp	Wed Apr 30 02:41:00 2014 +0200
+++ b/hotspot/src/share/vm/gc_implementation/parallelScavenge/parallelScavengeHeap.cpp	Fri May 02 02:11:34 2014 +0200
@@ -623,11 +623,11 @@
 }
 
 void ParallelScavengeHeap::print_tracing_info() const {
-  if (TraceGen0Time) {
+  if (TraceYoungGenTime) {
     double time = PSScavenge::accumulated_time()->seconds();
     tty->print_cr("[Accumulated GC generation 0 time %3.7f secs]", time);
   }
-  if (TraceGen1Time) {
+  if (TraceOldGenTime) {
     double time = UseParallelOldGC ? PSParallelCompact::accumulated_time()->seconds() : PSMarkSweep::accumulated_time()->seconds();
     tty->print_cr("[Accumulated GC generation 1 time %3.7f secs]", time);
   }
--- a/hotspot/src/share/vm/gc_implementation/parallelScavenge/psMarkSweep.cpp	Wed Apr 30 02:41:00 2014 +0200
+++ b/hotspot/src/share/vm/gc_implementation/parallelScavenge/psMarkSweep.cpp	Fri May 02 02:11:34 2014 +0200
@@ -174,7 +174,7 @@
     TraceCollectorStats tcs(counters());
     TraceMemoryManagerStats tms(true /* Full GC */,gc_cause);
 
-    if (TraceGen1Time) accumulated_time()->start();
+    if (TraceOldGenTime) accumulated_time()->start();
 
     // Let the size policy know we're starting
     size_policy->major_collection_begin();
@@ -354,7 +354,7 @@
     // We collected the heap, recalculate the metaspace capacity
     MetaspaceGC::compute_new_size();
 
-    if (TraceGen1Time) accumulated_time()->stop();
+    if (TraceOldGenTime) accumulated_time()->stop();
 
     if (PrintGC) {
       if (PrintGCDetails) {
--- a/hotspot/src/share/vm/gc_implementation/parallelScavenge/psParallelCompact.cpp	Wed Apr 30 02:41:00 2014 +0200
+++ b/hotspot/src/share/vm/gc_implementation/parallelScavenge/psParallelCompact.cpp	Fri May 02 02:11:34 2014 +0200
@@ -2061,7 +2061,7 @@
     TraceCollectorStats tcs(counters());
     TraceMemoryManagerStats tms(true /* Full GC */,gc_cause);
 
-    if (TraceGen1Time) accumulated_time()->start();
+    if (TraceOldGenTime) accumulated_time()->start();
 
     // Let the size policy know we're starting
     size_policy->major_collection_begin();
@@ -2188,7 +2188,7 @@
     // Resize the metaspace capacity after a collection
     MetaspaceGC::compute_new_size();
 
-    if (TraceGen1Time) accumulated_time()->stop();
+    if (TraceOldGenTime) accumulated_time()->stop();
 
     if (PrintGC) {
       if (PrintGCDetails) {
--- a/hotspot/src/share/vm/gc_implementation/parallelScavenge/psScavenge.cpp	Wed Apr 30 02:41:00 2014 +0200
+++ b/hotspot/src/share/vm/gc_implementation/parallelScavenge/psScavenge.cpp	Fri May 02 02:11:34 2014 +0200
@@ -336,7 +336,7 @@
     TraceCollectorStats tcs(counters());
     TraceMemoryManagerStats tms(false /* not full GC */,gc_cause);
 
-    if (TraceGen0Time) accumulated_time()->start();
+    if (TraceYoungGenTime) accumulated_time()->start();
 
     // Let the size policy know we're starting
     size_policy->minor_collection_begin();
@@ -660,7 +660,7 @@
       CardTableExtension::verify_all_young_refs_imprecise();
     }
 
-    if (TraceGen0Time) accumulated_time()->stop();
+    if (TraceYoungGenTime) accumulated_time()->stop();
 
     if (PrintGC) {
       if (PrintGCDetails) {
--- a/hotspot/src/share/vm/memory/collectorPolicy.cpp	Wed Apr 30 02:41:00 2014 +0200
+++ b/hotspot/src/share/vm/memory/collectorPolicy.cpp	Fri May 02 02:11:34 2014 +0200
@@ -196,13 +196,13 @@
 // GenCollectorPolicy methods
 
 GenCollectorPolicy::GenCollectorPolicy() :
-    _min_gen0_size(0),
-    _initial_gen0_size(0),
-    _max_gen0_size(0),
+    _min_young_size(0),
+    _initial_young_size(0),
+    _max_young_size(0),
     _gen_alignment(0),
-    _min_gen1_size(0),
-    _initial_gen1_size(0),
-    _max_gen1_size(0),
+    _min_old_size(0),
+    _initial_old_size(0),
+    _max_old_size(0),
     _generations(NULL)
 {}
 
@@ -236,7 +236,7 @@
 #ifdef ASSERT
 void GenCollectorPolicy::assert_flags() {
   CollectorPolicy::assert_flags();
-  assert(NewSize >= _min_gen0_size, "Ergonomics decided on a too small young gen size");
+  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");
@@ -249,28 +249,28 @@
   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_gen0_size, "Discrepancy between NewSize flag and local storage");
-  assert(MaxNewSize == _max_gen0_size, "Discrepancy between MaxNewSize flag and local storage");
-  assert(OldSize == _initial_gen1_size, "Discrepancy between OldSize flag and local storage");
-  assert(_min_gen0_size <= _initial_gen0_size, "Ergonomics decided on incompatible minimum and initial young gen sizes");
-  assert(_initial_gen0_size <= _max_gen0_size, "Ergonomics decided on incompatible initial and maximum young gen sizes");
-  assert(_min_gen0_size % _gen_alignment == 0, "_min_gen0_size alignment");
-  assert(_initial_gen0_size % _gen_alignment == 0, "_initial_gen0_size alignment");
-  assert(_max_gen0_size % _gen_alignment == 0, "_max_gen0_size alignment");
-  assert(_min_gen0_size <= bound_minus_alignment(_min_gen0_size, _min_heap_byte_size),
+  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_gen0_size <=  bound_minus_alignment(_initial_gen0_size, _initial_heap_byte_size),
+  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_gen0_size <= bound_minus_alignment(_max_gen0_size, _max_heap_byte_size),
+  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_gen1_size <= _initial_gen1_size, "Ergonomics decided on incompatible minimum and initial old gen sizes");
-  assert(_initial_gen1_size <= _max_gen1_size, "Ergonomics decided on incompatible initial and maximum old gen sizes");
-  assert(_max_gen1_size % _gen_alignment == 0, "_max_gen1_size alignment");
-  assert(_initial_gen1_size % _gen_alignment == 0, "_initial_gen1_size alignment");
-  assert(_max_heap_byte_size <= (_max_gen0_size + _max_gen1_size), "Total maximum heap sizes must be sum of generation maximum sizes");
-  assert(_min_gen0_size + _min_gen1_size <= _min_heap_byte_size, "Minimum generation sizes exceed minimum heap size");
-  assert(_initial_gen0_size + _initial_gen1_size == _initial_heap_byte_size, "Initial generation sizes should match initial heap size");
-  assert(_max_gen0_size + _max_gen1_size == _max_heap_byte_size, "Maximum generation sizes should match maximum heap size");
+  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
 
@@ -323,8 +323,8 @@
     // later when setting the initial and minimum young generation size.
     NewSize = bounded_new_size;
   }
-  _min_gen0_size = smallest_new_size;
-  _initial_gen0_size = NewSize;
+  _min_young_size = smallest_new_size;
+  _initial_young_size = NewSize;
 
   if (!FLAG_IS_DEFAULT(MaxNewSize)) {
     if (MaxNewSize >= MaxHeapSize) {
@@ -338,14 +338,14 @@
       FLAG_SET_ERGO(uintx, MaxNewSize, smaller_max_new_size);
       if (NewSize > MaxNewSize) {
         FLAG_SET_ERGO(uintx, NewSize, MaxNewSize);
-        _initial_gen0_size = NewSize;
+        _initial_young_size = NewSize;
       }
-    } else if (MaxNewSize < _initial_gen0_size) {
-      FLAG_SET_ERGO(uintx, MaxNewSize, _initial_gen0_size);
+    } else if (MaxNewSize < _initial_young_size) {
+      FLAG_SET_ERGO(uintx, MaxNewSize, _initial_young_size);
     } else if (!is_size_aligned(MaxNewSize, _gen_alignment)) {
       FLAG_SET_ERGO(uintx, MaxNewSize, align_size_down(MaxNewSize, _gen_alignment));
     }
-    _max_gen0_size = MaxNewSize;
+    _max_young_size = MaxNewSize;
   }
 
   if (NewSize > MaxNewSize) {
@@ -357,7 +357,7 @@
               NewSize/K, MaxNewSize/K, NewSize/K);
     }
     FLAG_SET_ERGO(uintx, MaxNewSize, NewSize);
-    _max_gen0_size = MaxNewSize;
+    _max_young_size = MaxNewSize;
   }
 
   if (SurvivorRatio < 1 || NewRatio < 1) {
@@ -393,7 +393,7 @@
       double shrink_factor = (double) MaxHeapSize / calculated_size;
       uintx smaller_new_size = align_size_down((uintx)(NewSize * shrink_factor), _gen_alignment);
       FLAG_SET_ERGO(uintx, NewSize, MAX2(young_gen_size_lower_bound(), smaller_new_size));
-      _initial_gen0_size = NewSize;
+      _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
@@ -406,16 +406,16 @@
     }
   }
 
-  // Update NewSize, if possible, to avoid sizing gen0 to small when only
+  // 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_gen0_size
+      // Need to compare against the flag value for max since _max_young_size
       // might not have been set yet.
-      if (new_size >= _min_gen0_size && new_size <= MaxNewSize) {
+      if (new_size >= _min_young_size && new_size <= MaxNewSize) {
         FLAG_SET_ERGO(uintx, NewSize, new_size);
-        _initial_gen0_size = NewSize;
+        _initial_young_size = NewSize;
       }
     }
   }
@@ -444,77 +444,77 @@
 void GenCollectorPolicy::initialize_size_info() {
   CollectorPolicy::initialize_size_info();
 
-  _initial_gen0_size = NewSize;
-  _max_gen0_size = MaxNewSize;
-  _initial_gen1_size = OldSize;
+  _initial_young_size = NewSize;
+  _max_young_size = MaxNewSize;
+  _initial_old_size = OldSize;
 
-  // Determine maximum size of gen0
+  // Determine maximum size of the young generation.
 
   if (FLAG_IS_DEFAULT(MaxNewSize)) {
-    _max_gen0_size = scale_by_NewRatio_aligned(_max_heap_byte_size);
+    _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_gen0_size = MIN2(MAX2(_max_gen0_size, _initial_gen0_size), MaxNewSize);
+    _max_young_size = MIN2(MAX2(_max_young_size, _initial_young_size), MaxNewSize);
   }
 
-  // Given the maximum gen0 size, determine the initial and
-  // minimum gen0 sizes.
+  // 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_gen0_size = FLAG_IS_CMDLINE(NewSize) ? NewSize : _max_gen0_size;
-    _initial_gen0_size = _max_gen0_size;
+    _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_gen0_size = _max_gen0_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_gen0_size =
-        MIN2(_max_gen0_size, bound_minus_alignment(NewSize, _initial_heap_byte_size));
-      _min_gen0_size = bound_minus_alignment(_initial_gen0_size, _min_heap_byte_size);
+      _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_gen0_size =
-        MIN2(_max_gen0_size, MAX2(scale_by_NewRatio_aligned(_initial_heap_byte_size), NewSize));
+      _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 gen0 " SIZE_FORMAT "  Initial gen0 "
-      SIZE_FORMAT "  Maximum gen0 " SIZE_FORMAT,
-      _min_gen0_size, _initial_gen0_size, _max_gen0_size);
+    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 gen0 have been determined.
-  // The maximum gen1 size can be determined from the maximum gen0
+  // 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 gen1 maximum.
-  _max_gen1_size = MAX2(_max_heap_byte_size - _max_gen0_size, _gen_alignment);
+  // 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
-  // gen1 size, use what is left for gen1
+  // 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 gen0 sizes and the overall heap sizes.
-    _min_gen1_size = _gen_alignment;
-    _initial_gen1_size = MIN2(_max_gen1_size, MAX2(_initial_heap_byte_size - _initial_gen0_size, _min_gen1_size));
-    // _max_gen1_size has already been made consistent above
+    // 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
@@ -523,68 +523,68 @@
     // with other command line flags, issue a warning.
     // The generation minimums and the overall heap minimum should
     // be within one generation alignment.
-    if (_initial_gen1_size > _max_gen1_size) {
+    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_gen1_size = _max_gen1_size;
+      _initial_old_size = _max_old_size;
     }
 
-    _min_gen1_size = MIN2(_initial_gen1_size, _min_heap_byte_size - _min_gen0_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_gen1_size + _initial_gen0_size) != _initial_heap_byte_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_gen0_size = _initial_heap_byte_size - _initial_gen1_size;
-    if (_initial_heap_byte_size < _initial_gen1_size) {
+    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_gen0_size = _min_gen0_size;
-      _initial_gen1_size = _initial_heap_byte_size - _min_gen0_size;
-    } else if (desired_gen0_size > _max_gen0_size) {
+      _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_gen0_size = _max_gen0_size;
-      _initial_gen1_size = _initial_heap_byte_size - _max_gen0_size;
-    } else if (desired_gen0_size < _min_gen0_size) {
+      _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_gen0_size = _min_gen0_size;
-      _initial_gen1_size = _initial_heap_byte_size - _min_gen0_size;
+      _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_gen0_size = desired_gen0_size;
+      _initial_young_size = desired_young_size;
     }
 
     if (PrintGCDetails && Verbose) {
-      gclog_or_tty->print_cr("2: Minimum gen0 " SIZE_FORMAT "  Initial gen0 "
-        SIZE_FORMAT "  Maximum gen0 " SIZE_FORMAT,
-        _min_gen0_size, _initial_gen0_size, _max_gen0_size);
+      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_gen0_size) {
-    FLAG_SET_ERGO(uintx, NewSize, _initial_gen0_size);
+  // Write back to flags if necessary.
+  if (NewSize != _initial_young_size) {
+    FLAG_SET_ERGO(uintx, NewSize, _initial_young_size);
   }
 
-  if (MaxNewSize != _max_gen0_size) {
-    FLAG_SET_ERGO(uintx, MaxNewSize, _max_gen0_size);
+  if (MaxNewSize != _max_young_size) {
+    FLAG_SET_ERGO(uintx, MaxNewSize, _max_young_size);
   }
 
-  if (OldSize != _initial_gen1_size) {
-    FLAG_SET_ERGO(uintx, OldSize, _initial_gen1_size);
+  if (OldSize != _initial_old_size) {
+    FLAG_SET_ERGO(uintx, OldSize, _initial_old_size);
   }
 
   if (PrintGCDetails && Verbose) {
-    gclog_or_tty->print_cr("Minimum gen1 " SIZE_FORMAT "  Initial gen1 "
-      SIZE_FORMAT "  Maximum gen1 " SIZE_FORMAT,
-      _min_gen1_size, _initial_gen1_size, _max_gen1_size);
+    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();)
@@ -610,11 +610,11 @@
     HandleMark hm; // Discard any handles allocated in each iteration.
 
     // First allocation attempt is lock-free.
-    Generation *gen0 = gch->get_gen(0);
-    assert(gen0->supports_inline_contig_alloc(),
+    Generation *young = gch->get_gen(0);
+    assert(young->supports_inline_contig_alloc(),
       "Otherwise, must do alloc within heap lock");
-    if (gen0->should_allocate(size, is_tlab)) {
-      result = gen0->par_allocate(size, is_tlab);
+    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;
@@ -896,8 +896,8 @@
 bool GenCollectorPolicy::should_try_older_generation_allocation(
         size_t word_size) const {
   GenCollectedHeap* gch = GenCollectedHeap::heap();
-  size_t gen0_capacity = gch->get_gen(0)->capacity_before_gc();
-  return    (word_size > heap_word_size(gen0_capacity))
+  size_t young_capacity = gch->get_gen(0)->capacity_before_gc();
+  return    (word_size > heap_word_size(young_capacity))
          || GC_locker::is_active_and_needs_gc()
          || gch->incremental_collection_failed();
 }
@@ -919,11 +919,11 @@
   }
 
   if (UseParNewGC) {
-    _generations[0] = new GenerationSpec(Generation::ParNew, _initial_gen0_size, _max_gen0_size);
+    _generations[0] = new GenerationSpec(Generation::ParNew, _initial_young_size, _max_young_size);
   } else {
-    _generations[0] = new GenerationSpec(Generation::DefNew, _initial_gen0_size, _max_gen0_size);
+    _generations[0] = new GenerationSpec(Generation::DefNew, _initial_young_size, _max_young_size);
   }
-  _generations[1] = new GenerationSpec(Generation::MarkSweepCompact, _initial_gen1_size, _max_gen1_size);
+  _generations[1] = new GenerationSpec(Generation::MarkSweepCompact, _initial_old_size, _max_old_size);
 
   if (_generations[0] == NULL || _generations[1] == NULL) {
     vm_exit_during_initialization("Unable to allocate gen spec");
@@ -957,18 +957,18 @@
     flag_value = 20 * M;
     set_basic_flag_values();
     FLAG_SET_CMDLINE(uintx, NewSize, flag_value);
-    verify_gen0_min(flag_value);
+    verify_young_min(flag_value);
 
     set_basic_flag_values();
     FLAG_SET_CMDLINE(uintx, NewSize, flag_value);
-    verify_gen0_initial(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(uintx, NewSize, flag_value);
-    verify_gen0_initial(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
@@ -976,11 +976,11 @@
     flag_value = 20 * M;
     set_basic_flag_values();
     FLAG_SET_ERGO(uintx, NewSize, flag_value);
-    verify_gen0_min(flag_value);
+    verify_young_min(flag_value);
 
     set_basic_flag_values();
     FLAG_SET_ERGO(uintx, NewSize, flag_value);
-    verify_scaled_gen0_initial(InitialHeapSize);
+    verify_scaled_young_initial(InitialHeapSize);
 
     restore_flags();
   }
@@ -995,11 +995,11 @@
       flag_value = 20 * M;
       set_basic_flag_values();
       FLAG_SET_CMDLINE(uintx, OldSize, flag_value);
-      verify_gen1_min(flag_value);
+      verify_old_min(flag_value);
 
       set_basic_flag_values();
       FLAG_SET_CMDLINE(uintx, OldSize, flag_value);
-      verify_gen1_initial(flag_value);
+      verify_old_initial(flag_value);
 
       // If MaxNewSize is large, the maximum OldSize will be less than
       // what's requested on the command line and it should be reset
@@ -1010,46 +1010,46 @@
       FLAG_SET_CMDLINE(uintx, MaxNewSize, 170*M);
       // Calculate what we expect the flag to be.
       flag_value = MaxHeapSize - MaxNewSize;
-      verify_gen1_initial(flag_value);
+      verify_old_initial(flag_value);
 
   }
 
-  static void verify_gen0_min(size_t expected) {
+  static void verify_young_min(size_t expected) {
     MarkSweepPolicy msp;
     msp.initialize_all();
 
-    assert(msp.min_gen0_size() <= expected, err_msg("%zu  > %zu", msp.min_gen0_size(), expected));
+    assert(msp.min_young_size() <= expected, err_msg("%zu  > %zu", msp.min_young_size(), expected));
   }
 
-  static void verify_gen0_initial(size_t expected) {
+  static void verify_young_initial(size_t expected) {
     MarkSweepPolicy msp;
     msp.initialize_all();
 
-    assert(msp.initial_gen0_size() == expected, err_msg("%zu != %zu", msp.initial_gen0_size(), expected));
+    assert(msp.initial_young_size() == expected, err_msg("%zu != %zu", msp.initial_young_size(), expected));
   }
 
-  static void verify_scaled_gen0_initial(size_t initial_heap_size) {
+  static void verify_scaled_young_initial(size_t initial_heap_size) {
     MarkSweepPolicy msp;
     msp.initialize_all();
 
     size_t expected = msp.scale_by_NewRatio_aligned(initial_heap_size);
-    assert(msp.initial_gen0_size() == expected, err_msg("%zu != %zu", msp.initial_gen0_size(), expected));
+    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_gen1_min(size_t expected) {
+  static void verify_old_min(size_t expected) {
     MarkSweepPolicy msp;
     msp.initialize_all();
 
-    assert(msp.min_gen1_size() <= expected, err_msg("%zu  > %zu", msp.min_gen1_size(), expected));
+    assert(msp.min_old_size() <= expected, err_msg("%zu  > %zu", msp.min_old_size(), expected));
   }
 
-  static void verify_gen1_initial(size_t expected) {
+  static void verify_old_initial(size_t expected) {
     MarkSweepPolicy msp;
     msp.initialize_all();
 
-    assert(msp.initial_gen1_size() == expected, err_msg("%zu != %zu", msp.initial_gen1_size(), expected));
+    assert(msp.initial_old_size() == expected, err_msg("%zu != %zu", msp.initial_old_size(), expected));
   }
 
 
--- a/hotspot/src/share/vm/memory/collectorPolicy.hpp	Wed Apr 30 02:41:00 2014 +0200
+++ b/hotspot/src/share/vm/memory/collectorPolicy.hpp	Fri May 02 02:11:34 2014 +0200
@@ -219,12 +219,12 @@
 class GenCollectorPolicy : public CollectorPolicy {
 friend class TestGenCollectorPolicy;
  protected:
-  size_t _min_gen0_size;
-  size_t _initial_gen0_size;
-  size_t _max_gen0_size;
-  size_t _min_gen1_size;
-  size_t _initial_gen1_size;
-  size_t _max_gen1_size;
+  size_t _min_young_size;
+  size_t _initial_young_size;
+  size_t _max_young_size;
+  size_t _min_old_size;
+  size_t _initial_old_size;
+  size_t _max_old_size;
 
   // _gen_alignment and _space_alignment will have the same value most of the
   // time. When using large pages they can differ.
@@ -260,13 +260,13 @@
   GenCollectorPolicy();
 
   // Accessors
-  size_t min_gen0_size()     { return _min_gen0_size; }
-  size_t initial_gen0_size() { return _initial_gen0_size; }
-  size_t max_gen0_size()     { return _max_gen0_size; }
-  size_t gen_alignment()     { return _gen_alignment; }
-  size_t min_gen1_size()     { return _min_gen1_size; }
-  size_t initial_gen1_size() { return _initial_gen1_size; }
-  size_t max_gen1_size()     { return _max_gen1_size; }
+  size_t min_young_size()     { return _min_young_size; }
+  size_t initial_young_size() { return _initial_young_size; }
+  size_t max_young_size()     { return _max_young_size; }
+  size_t gen_alignment()      { return _gen_alignment; }
+  size_t min_old_size()       { return _min_old_size; }
+  size_t initial_old_size()   { return _initial_old_size; }
+  size_t max_old_size()       { return _max_old_size; }
 
   int number_of_generations() { return 2; }
 
@@ -298,7 +298,7 @@
                                       size_t init_survivor_size);
 
   virtual void post_heap_initialize() {
-    assert(_max_gen0_size == MaxNewSize, "Should be taken care of by initialize_size_info");
+    assert(_max_young_size == MaxNewSize, "Should be taken care of by initialize_size_info");
   }
 
   BarrierSet::Name barrier_set_name()  { return BarrierSet::CardTableModRef; }
--- a/hotspot/src/share/vm/memory/genCollectedHeap.cpp	Wed Apr 30 02:41:00 2014 +0200
+++ b/hotspot/src/share/vm/memory/genCollectedHeap.cpp	Fri May 02 02:11:34 2014 +0200
@@ -1119,10 +1119,10 @@
 }
 
 void GenCollectedHeap::print_tracing_info() const {
-  if (TraceGen0Time) {
+  if (TraceYoungGenTime) {
     get_gen(0)->print_summary_info();
   }
-  if (TraceGen1Time) {
+  if (TraceOldGenTime) {
     get_gen(1)->print_summary_info();
   }
 }
--- a/hotspot/src/share/vm/memory/tenuredGeneration.hpp	Wed Apr 30 02:41:00 2014 +0200
+++ b/hotspot/src/share/vm/memory/tenuredGeneration.hpp	Fri May 02 02:11:34 2014 +0200
@@ -67,10 +67,9 @@
   // Does a "full" (forced) collection invoked on this generation collect
   // all younger generations as well? Note that this is a
   // hack to allow the collection of the younger gen first if the flag is
-  // set. This is better than using th policy's should_collect_gen0_first()
-  // since that causes us to do an extra unnecessary pair of restart-&-stop-world.
+  // set.
   virtual bool full_collects_younger_generations() const {
-    return !CollectGen0First;
+    return !ScavengeBeforeFullGC;
   }
 
   virtual void gc_prologue(bool full);
--- a/hotspot/src/share/vm/runtime/arguments.cpp	Wed Apr 30 02:41:00 2014 +0200
+++ b/hotspot/src/share/vm/runtime/arguments.cpp	Fri May 02 02:11:34 2014 +0200
@@ -2187,6 +2187,10 @@
     }
   }
 
+  if (!(UseParallelGC || UseParallelOldGC) && FLAG_IS_DEFAULT(ScavengeBeforeFullGC)) {
+    FLAG_SET_DEFAULT(ScavengeBeforeFullGC, false);
+  }
+
   status = status && verify_percentage(GCHeapFreeLimit, "GCHeapFreeLimit");
   status = status && verify_percentage(GCTimeLimit, "GCTimeLimit");
   if (GCTimeLimit == 100) {
--- a/hotspot/src/share/vm/runtime/globals.hpp	Wed Apr 30 02:41:00 2014 +0200
+++ b/hotspot/src/share/vm/runtime/globals.hpp	Fri May 02 02:11:34 2014 +0200
@@ -1450,8 +1450,7 @@
           "(ParallelGC only)")                                              \
                                                                             \
   product(bool, ScavengeBeforeFullGC, true,                                 \
-          "Scavenge youngest generation before each full GC, "              \
-          "used with UseParallelGC")                                        \
+          "Scavenge youngest generation before each full GC.")              \
                                                                             \
   develop(bool, ScavengeWithObjectsInToSpace, false,                        \
           "Allow scavenges to occur when to-space contains objects")        \
@@ -2252,9 +2251,6 @@
   notproduct(bool, CheckMemoryInitialization, false,                        \
           "Check memory initialization")                                    \
                                                                             \
-  product(bool, CollectGen0First, false,                                    \
-          "Collect youngest generation before each full GC")                \
-                                                                            \
   diagnostic(bool, BindCMSThreadToCPU, false,                               \
           "Bind CMS Thread to CPU if possible")                             \
                                                                             \
@@ -2333,11 +2329,11 @@
           NOT_LP64(2200*K) LP64_ONLY(4*M),                                  \
           "Initial size of the boot class loader data metaspace")           \
                                                                             \
-  product(bool, TraceGen0Time, false,                                       \
-          "Trace accumulated time for Gen 0 collection")                    \
-                                                                            \
-  product(bool, TraceGen1Time, false,                                       \
-          "Trace accumulated time for Gen 1 collection")                    \
+  product(bool, TraceYoungGenTime, false,                                   \
+          "Trace accumulated time for young collection")                    \
+                                                                            \
+  product(bool, TraceOldGenTime, false,                                     \
+          "Trace accumulated time for old collection")                      \
                                                                             \
   product(bool, PrintTenuringDistribution, false,                           \
           "Print tenuring age information")                                 \