--- a/src/share/vm/gc_implementation/g1/g1CollectorPolicy.cpp	Thu Nov 17 13:14:49 2011 -0500
+++ b/src/share/vm/gc_implementation/g1/g1CollectorPolicy.cpp	Fri Nov 18 12:52:27 2011 -0500
@@ -36,10 +36,6 @@
 #include "runtime/mutexLocker.hpp"
 #include "utilities/debug.hpp"
 
-#define PREDICTIONS_VERBOSE 0
-
-// <NEW PREDICTION>
-
 // Different defaults for different number of GC threads
 // They were chosen by running GCOld and SPECjbb on debris with different
 //   numbers of GC threads and choosing them based on the results
@@ -80,8 +76,6 @@
   1.0, 0.7, 0.7, 0.5, 0.5, 0.42, 0.42, 0.30
 };
 
-// </NEW PREDICTION>
-
 // Help class for avoiding interleaved logging
 class LineBuffer: public StackObj {
 
@@ -137,10 +131,6 @@
   _parallel_gc_threads(G1CollectedHeap::use_parallel_gc_threads()
                         ? ParallelGCThreads : 1),
 
-  _n_pauses(0),
-  _recent_rs_scan_times_ms(new TruncatedSeq(NumPrevPausesForHeuristics)),
-  _recent_pause_times_ms(new TruncatedSeq(NumPrevPausesForHeuristics)),
-  _recent_rs_sizes(new TruncatedSeq(NumPrevPausesForHeuristics)),
   _recent_gc_times_ms(new TruncatedSeq(NumPrevPausesForHeuristics)),
   _all_pause_times_ms(new NumberSeq()),
   _stop_world_start(0.0),
@@ -148,8 +138,6 @@
   _all_yield_times_ms(new NumberSeq()),
   _using_new_ratio_calculations(false),
 
-  _all_mod_union_times_ms(new NumberSeq()),
-
   _summary(new Summary()),
 
   _cur_clear_ct_time_ms(0.0),
@@ -165,11 +153,6 @@
   _num_cc_clears(0L),
 #endif
 
-  _region_num_young(0),
-  _region_num_tenured(0),
-  _prev_region_num_young(0),
-  _prev_region_num_tenured(0),
-
   _aux_num(10),
   _all_aux_times_ms(new NumberSeq[_aux_num]),
   _cur_aux_start_times_ms(new double[_aux_num]),
@@ -179,8 +162,6 @@
   _concurrent_mark_remark_times_ms(new TruncatedSeq(NumPrevPausesForHeuristics)),
   _concurrent_mark_cleanup_times_ms(new TruncatedSeq(NumPrevPausesForHeuristics)),
 
-  // <NEW PREDICTION>
-
   _alloc_rate_ms_seq(new TruncatedSeq(TruncatedSeqLength)),
   _prev_collection_pause_end_ms(0.0),
   _pending_card_diff_seq(new TruncatedSeq(TruncatedSeqLength)),
@@ -199,13 +180,10 @@
                                          new TruncatedSeq(TruncatedSeqLength)),
 
   _pending_cards_seq(new TruncatedSeq(TruncatedSeqLength)),
-  _scanned_cards_seq(new TruncatedSeq(TruncatedSeqLength)),
   _rs_lengths_seq(new TruncatedSeq(TruncatedSeqLength)),
 
   _pause_time_target_ms((double) MaxGCPauseMillis),
 
-  // </NEW PREDICTION>
-
   _full_young_gcs(true),
   _full_young_pause_num(0),
   _partial_young_pause_num(0),
@@ -221,16 +199,10 @@
 
    _recent_prev_end_times_for_all_gcs_sec(new TruncatedSeq(NumPrevPausesForHeuristics)),
 
-  _recent_CS_bytes_used_before(new TruncatedSeq(NumPrevPausesForHeuristics)),
-  _recent_CS_bytes_surviving(new TruncatedSeq(NumPrevPausesForHeuristics)),
-
   _recent_avg_pause_time_ratio(0.0),
 
   _all_full_gc_times_ms(new NumberSeq()),
 
-  // G1PausesBtwnConcMark defaults to -1
-  // so the hack is to do the cast  QQQ FIXME
-  _pauses_btwn_concurrent_mark((size_t)G1PausesBtwnConcMark),
   _initiate_conc_mark_if_possible(false),
   _during_initial_mark_pause(false),
   _should_revert_to_full_young_gcs(false),
@@ -242,22 +214,21 @@
 
   _prev_collection_pause_used_at_end_bytes(0),
 
+  _eden_cset_region_length(0),
+  _survivor_cset_region_length(0),
+  _old_cset_region_length(0),
+
   _collection_set(NULL),
-  _collection_set_size(0),
   _collection_set_bytes_used_before(0),
 
   // Incremental CSet attributes
   _inc_cset_build_state(Inactive),
   _inc_cset_head(NULL),
   _inc_cset_tail(NULL),
-  _inc_cset_size(0),
-  _inc_cset_young_index(0),
   _inc_cset_bytes_used_before(0),
   _inc_cset_max_finger(NULL),
-  _inc_cset_recorded_young_bytes(0),
   _inc_cset_recorded_rs_lengths(0),
   _inc_cset_predicted_elapsed_time_ms(0.0),
-  _inc_cset_predicted_bytes_to_copy(0),
 
 #ifdef _MSC_VER // the use of 'this' below gets a warning, make it go away
 #pragma warning( disable:4355 ) // 'this' : used in base member initializer list
@@ -325,8 +296,6 @@
   // start conservatively
   _expensive_region_limit_ms = 0.5 * (double) MaxGCPauseMillis;
 
-  // <NEW PREDICTION>
-
   int index;
   if (ParallelGCThreads == 0)
     index = 0;
@@ -348,8 +317,6 @@
   _non_young_other_cost_per_region_ms_seq->add(
                            non_young_other_cost_per_region_ms_defaults[index]);
 
-  // </NEW PREDICTION>
-
   // Below, we might need to calculate the pause time target based on
   // the pause interval. When we do so we are going to give G1 maximum
   // flexibility and allow it to do pauses when it needs to. So, we'll
@@ -908,9 +875,6 @@
 
   record_survivor_regions(0, NULL, NULL);
 
-  _prev_region_num_young   = _region_num_young;
-  _prev_region_num_tenured = _region_num_tenured;
-
   _free_regions_at_end_of_collection = _g1->free_regions();
   // Reset survivors SurvRateGroup.
   _survivor_surv_rate_group->reset();
@@ -1168,8 +1132,10 @@
   double end_time_sec = os::elapsedTime();
   double elapsed_ms = _last_pause_time_ms;
   bool parallel = G1CollectedHeap::use_parallel_gc_threads();
+  assert(_cur_collection_pause_used_regions_at_start >= cset_region_length(),
+         "otherwise, the subtraction below does not make sense");
   size_t rs_size =
-    _cur_collection_pause_used_regions_at_start - collection_set_size();
+            _cur_collection_pause_used_regions_at_start - cset_region_length();
   size_t cur_used_bytes = _g1->used();
   assert(cur_used_bytes == _g1->recalculate_used(), "It should!");
   bool last_pause_included_initial_mark = false;
@@ -1226,10 +1192,6 @@
   _mmu_tracker->add_pause(end_time_sec - elapsed_ms/1000.0,
                           end_time_sec, false);
 
-  guarantee(_cur_collection_pause_used_regions_at_start >=
-            collection_set_size(),
-            "Negative RS size?");
-
   // This assert is exempted when we're doing parallel collection pauses,
   // because the fragmentation caused by the parallel GC allocation buffers
   // can lead to more memory being used during collection than was used
@@ -1253,8 +1215,6 @@
     (double)surviving_bytes/
     (double)_collection_set_bytes_used_before;
 
-  _n_pauses++;
-
   // These values are used to update the summary information that is
   // displayed when TraceGen0Time is enabled, and are output as part
   // of the PrintGCDetails output, in the non-parallel case.
@@ -1295,10 +1255,6 @@
   _all_pause_times_ms->add(elapsed_ms);
 
   if (update_stats) {
-    _recent_rs_scan_times_ms->add(scan_rs_time);
-    _recent_pause_times_ms->add(elapsed_ms);
-    _recent_rs_sizes->add(rs_size);
-
     _summary->record_total_time_ms(elapsed_ms);
     _summary->record_other_time_ms(other_time_ms);
 
@@ -1342,9 +1298,6 @@
            || surviving_bytes <= _collection_set_bytes_used_before,
            "Or else negative collection!");
 
-    _recent_CS_bytes_used_before->add(_collection_set_bytes_used_before);
-    _recent_CS_bytes_surviving->add(surviving_bytes);
-
     // this is where we update the allocation rate of the application
     double app_time_ms =
       (_cur_collection_start_sec * 1000.0 - _prev_collection_pause_end_ms);
@@ -1354,13 +1307,17 @@
       // We'll just set it to something (arbitrarily) small.
       app_time_ms = 1.0;
     }
-    size_t regions_allocated =
-      (_region_num_young - _prev_region_num_young) +
-      (_region_num_tenured - _prev_region_num_tenured);
+    // We maintain the invariant that all objects allocated by mutator
+    // threads will be allocated out of eden regions. So, we can use
+    // the eden region number allocated since the previous GC to
+    // calculate the application's allocate rate. The only exception
+    // to that is humongous objects that are allocated separately. But
+    // given that humongous object allocations do not really affect
+    // either the pause's duration nor when the next pause will take
+    // place we can safely ignore them here.
+    size_t regions_allocated = eden_cset_region_length();
     double alloc_rate_ms = (double) regions_allocated / app_time_ms;
     _alloc_rate_ms_seq->add(alloc_rate_ms);
-    _prev_region_num_young   = _region_num_young;
-    _prev_region_num_tenured = _region_num_tenured;
 
     double interval_ms =
       (end_time_sec - _recent_prev_end_times_for_all_gcs_sec->oldest()) * 1000.0;
@@ -1398,33 +1355,6 @@
     }
   }
 
-
-  if (G1PolicyVerbose > 1) {
-    gclog_or_tty->print_cr("   Recording collection pause(%d)", _n_pauses);
-  }
-
-  if (G1PolicyVerbose > 1) {
-    gclog_or_tty->print_cr("      ET: %10.6f ms           (avg: %10.6f ms)\n"
-                           "       ET-RS:  %10.6f ms      (avg: %10.6f ms)\n"
-                           "      |RS|: " SIZE_FORMAT,
-                           elapsed_ms, recent_avg_time_for_pauses_ms(),
-                           scan_rs_time, recent_avg_time_for_rs_scan_ms(),
-                           rs_size);
-
-    gclog_or_tty->print_cr("       Used at start: " SIZE_FORMAT"K"
-                           "       At end " SIZE_FORMAT "K\n"
-                           "       garbage      : " SIZE_FORMAT "K"
-                           "       of     " SIZE_FORMAT "K\n"
-                           "       survival     : %6.2f%%  (%6.2f%% avg)",
-                           _cur_collection_pause_used_at_start_bytes/K,
-                           _g1->used()/K, freed_bytes/K,
-                           _collection_set_bytes_used_before/K,
-                           survival_fraction*100.0,
-                           recent_avg_survival_fraction()*100.0);
-    gclog_or_tty->print_cr("       Recent %% gc pause time: %6.2f",
-                           recent_avg_pause_time_ratio() * 100.0);
-  }
-
   // PrintGCDetails output
   if (PrintGCDetails) {
     bool print_marking_info =
@@ -1576,8 +1506,6 @@
   _short_lived_surv_rate_group->start_adding_regions();
   // do that for any other surv rate groupsx
 
-  // <NEW PREDICTION>
-
   if (update_stats) {
     double pause_time_ms = elapsed_ms;
 
@@ -1631,21 +1559,21 @@
        _mark_closure_time_ms + termination_time);
 
     double young_other_time_ms = 0.0;
-    if (_recorded_young_regions > 0) {
+    if (young_cset_region_length() > 0) {
       young_other_time_ms =
         _recorded_young_cset_choice_time_ms +
         _recorded_young_free_cset_time_ms;
       _young_other_cost_per_region_ms_seq->add(young_other_time_ms /
-                                             (double) _recorded_young_regions);
+                                          (double) young_cset_region_length());
     }
     double non_young_other_time_ms = 0.0;
-    if (_recorded_non_young_regions > 0) {
+    if (old_cset_region_length() > 0) {
       non_young_other_time_ms =
         _recorded_non_young_cset_choice_time_ms +
         _recorded_non_young_free_cset_time_ms;
 
       _non_young_other_cost_per_region_ms_seq->add(non_young_other_time_ms /
-                                         (double) _recorded_non_young_regions);
+                                            (double) old_cset_region_length());
     }
 
     double constant_other_time_ms = all_other_time_ms -
@@ -1659,7 +1587,6 @@
     }
 
     _pending_cards_seq->add((double) _pending_cards);
-    _scanned_cards_seq->add((double) cards_scanned);
     _rs_lengths_seq->add((double) _max_rs_lengths);
 
     double expensive_region_limit_ms =
@@ -1670,49 +1597,6 @@
       expensive_region_limit_ms = (double) MaxGCPauseMillis;
     }
     _expensive_region_limit_ms = expensive_region_limit_ms;
-
-    if (PREDICTIONS_VERBOSE) {
-      gclog_or_tty->print_cr("");
-      gclog_or_tty->print_cr("PREDICTIONS %1.4lf %d "
-                    "REGIONS %d %d %d "
-                    "PENDING_CARDS %d %d "
-                    "CARDS_SCANNED %d %d "
-                    "RS_LENGTHS %d %d "
-                    "RS_UPDATE %1.6lf %1.6lf RS_SCAN %1.6lf %1.6lf "
-                    "SURVIVAL_RATIO %1.6lf %1.6lf "
-                    "OBJECT_COPY %1.6lf %1.6lf OTHER_CONSTANT %1.6lf %1.6lf "
-                    "OTHER_YOUNG %1.6lf %1.6lf "
-                    "OTHER_NON_YOUNG %1.6lf %1.6lf "
-                    "VTIME_DIFF %1.6lf TERMINATION %1.6lf "
-                    "ELAPSED %1.6lf %1.6lf ",
-                    _cur_collection_start_sec,
-                    (!_last_young_gc_full) ? 2 :
-                    (last_pause_included_initial_mark) ? 1 : 0,
-                    _recorded_region_num,
-                    _recorded_young_regions,
-                    _recorded_non_young_regions,
-                    _predicted_pending_cards, _pending_cards,
-                    _predicted_cards_scanned, cards_scanned,
-                    _predicted_rs_lengths, _max_rs_lengths,
-                    _predicted_rs_update_time_ms, update_rs_time,
-                    _predicted_rs_scan_time_ms, scan_rs_time,
-                    _predicted_survival_ratio, survival_ratio,
-                    _predicted_object_copy_time_ms, obj_copy_time,
-                    _predicted_constant_other_time_ms, constant_other_time_ms,
-                    _predicted_young_other_time_ms, young_other_time_ms,
-                    _predicted_non_young_other_time_ms,
-                    non_young_other_time_ms,
-                    _vtime_diff_ms, termination_time,
-                    _predicted_pause_time_ms, elapsed_ms);
-    }
-
-    if (G1PolicyVerbose > 0) {
-      gclog_or_tty->print_cr("Pause Time, predicted: %1.4lfms (predicted %s), actual: %1.4lfms",
-                    _predicted_pause_time_ms,
-                    (_within_target) ? "within" : "outside",
-                    elapsed_ms);
-    }
-
   }
 
   _in_marking_window = new_in_marking_window;
@@ -1723,7 +1607,6 @@
   // Note that _mmu_tracker->max_gc_time() returns the time in seconds.
   double update_rs_time_goal_ms = _mmu_tracker->max_gc_time() * MILLIUNITS * G1RSetUpdatingPauseTimePercent / 100.0;
   adjust_concurrent_refinement(update_rs_time, update_rs_processed_buffers, update_rs_time_goal_ms);
-  // </NEW PREDICTION>
 
   assert(assertMarkedBytesDataOK(), "Marked regions not OK at pause end.");
 }
@@ -1768,8 +1651,6 @@
   }
 }
 
-// <NEW PREDICTION>
-
 void G1CollectorPolicy::adjust_concurrent_refinement(double update_rs_time,
                                                      double update_rs_processed_buffers,
                                                      double goal_ms) {
@@ -1905,98 +1786,17 @@
 }
 
 void
-G1CollectorPolicy::start_recording_regions() {
-  _recorded_rs_lengths            = 0;
-  _recorded_young_regions         = 0;
-  _recorded_non_young_regions     = 0;
-
-#if PREDICTIONS_VERBOSE
-  _recorded_marked_bytes          = 0;
-  _recorded_young_bytes           = 0;
-  _predicted_bytes_to_copy        = 0;
-  _predicted_rs_lengths           = 0;
-  _predicted_cards_scanned        = 0;
-#endif // PREDICTIONS_VERBOSE
-}
-
-void
-G1CollectorPolicy::record_cset_region_info(HeapRegion* hr, bool young) {
-#if PREDICTIONS_VERBOSE
-  if (!young) {
-    _recorded_marked_bytes += hr->max_live_bytes();
-  }
-  _predicted_bytes_to_copy += predict_bytes_to_copy(hr);
-#endif // PREDICTIONS_VERBOSE
-
-  size_t rs_length = hr->rem_set()->occupied();
-  _recorded_rs_lengths += rs_length;
-}
-
-void
-G1CollectorPolicy::record_non_young_cset_region(HeapRegion* hr) {
-  assert(!hr->is_young(), "should not call this");
-  ++_recorded_non_young_regions;
-  record_cset_region_info(hr, false);
-}
-
-void
-G1CollectorPolicy::set_recorded_young_regions(size_t n_regions) {
-  _recorded_young_regions = n_regions;
-}
-
-void G1CollectorPolicy::set_recorded_young_bytes(size_t bytes) {
-#if PREDICTIONS_VERBOSE
-  _recorded_young_bytes = bytes;
-#endif // PREDICTIONS_VERBOSE
+G1CollectorPolicy::init_cset_region_lengths(size_t eden_cset_region_length,
+                                          size_t survivor_cset_region_length) {
+  _eden_cset_region_length     = eden_cset_region_length;
+  _survivor_cset_region_length = survivor_cset_region_length;
+  _old_cset_region_length      = 0;
 }
 
 void G1CollectorPolicy::set_recorded_rs_lengths(size_t rs_lengths) {
   _recorded_rs_lengths = rs_lengths;
 }
 
-void G1CollectorPolicy::set_predicted_bytes_to_copy(size_t bytes) {
-  _predicted_bytes_to_copy = bytes;
-}
-
-void
-G1CollectorPolicy::end_recording_regions() {
-  // The _predicted_pause_time_ms field is referenced in code
-  // not under PREDICTIONS_VERBOSE. Let's initialize it.
-  _predicted_pause_time_ms = -1.0;
-
-#if PREDICTIONS_VERBOSE
-  _predicted_pending_cards = predict_pending_cards();
-  _predicted_rs_lengths = _recorded_rs_lengths + predict_rs_length_diff();
-  if (full_young_gcs())
-    _predicted_cards_scanned += predict_young_card_num(_predicted_rs_lengths);
-  else
-    _predicted_cards_scanned +=
-      predict_non_young_card_num(_predicted_rs_lengths);
-  _recorded_region_num = _recorded_young_regions + _recorded_non_young_regions;
-
-  _predicted_rs_update_time_ms =
-    predict_rs_update_time_ms(_g1->pending_card_num());
-  _predicted_rs_scan_time_ms =
-    predict_rs_scan_time_ms(_predicted_cards_scanned);
-  _predicted_object_copy_time_ms =
-    predict_object_copy_time_ms(_predicted_bytes_to_copy);
-  _predicted_constant_other_time_ms =
-    predict_constant_other_time_ms();
-  _predicted_young_other_time_ms =
-    predict_young_other_time_ms(_recorded_young_regions);
-  _predicted_non_young_other_time_ms =
-    predict_non_young_other_time_ms(_recorded_non_young_regions);
-
-  _predicted_pause_time_ms =
-    _predicted_rs_update_time_ms +
-    _predicted_rs_scan_time_ms +
-    _predicted_object_copy_time_ms +
-    _predicted_constant_other_time_ms +
-    _predicted_young_other_time_ms +
-    _predicted_non_young_other_time_ms;
-#endif // PREDICTIONS_VERBOSE
-}
-
 void G1CollectorPolicy::check_if_region_is_too_expensive(double
                                                            predicted_time_ms) {
   // I don't think we need to do this when in young GC mode since
@@ -2013,9 +1813,6 @@
   }
 }
 
-// </NEW PREDICTION>
-
-
 void G1CollectorPolicy::update_recent_gc_times(double end_time_sec,
                                                double elapsed_ms) {
   _recent_gc_times_ms->add(elapsed_ms);
@@ -2023,99 +1820,6 @@
   _prev_collection_pause_end_ms = end_time_sec * 1000.0;
 }
 
-double G1CollectorPolicy::recent_avg_time_for_pauses_ms() {
-  if (_recent_pause_times_ms->num() == 0) {
-    return (double) MaxGCPauseMillis;
-  }
-  return _recent_pause_times_ms->avg();
-}
-
-double G1CollectorPolicy::recent_avg_time_for_rs_scan_ms() {
-  if (_recent_rs_scan_times_ms->num() == 0) {
-    return (double)MaxGCPauseMillis/3.0;
-  }
-  return _recent_rs_scan_times_ms->avg();
-}
-
-int G1CollectorPolicy::number_of_recent_gcs() {
-  assert(_recent_rs_scan_times_ms->num() ==
-         _recent_pause_times_ms->num(), "Sequence out of sync");
-  assert(_recent_pause_times_ms->num() ==
-         _recent_CS_bytes_used_before->num(), "Sequence out of sync");
-  assert(_recent_CS_bytes_used_before->num() ==
-         _recent_CS_bytes_surviving->num(), "Sequence out of sync");
-
-  return _recent_pause_times_ms->num();
-}
-
-double G1CollectorPolicy::recent_avg_survival_fraction() {
-  return recent_avg_survival_fraction_work(_recent_CS_bytes_surviving,
-                                           _recent_CS_bytes_used_before);
-}
-
-double G1CollectorPolicy::last_survival_fraction() {
-  return last_survival_fraction_work(_recent_CS_bytes_surviving,
-                                     _recent_CS_bytes_used_before);
-}
-
-double
-G1CollectorPolicy::recent_avg_survival_fraction_work(TruncatedSeq* surviving,
-                                                     TruncatedSeq* before) {
-  assert(surviving->num() == before->num(), "Sequence out of sync");
-  if (before->sum() > 0.0) {
-      double recent_survival_rate = surviving->sum() / before->sum();
-      // We exempt parallel collection from this check because Alloc Buffer
-      // fragmentation can produce negative collections.
-      // Further, we're now always doing parallel collection.  But I'm still
-      // leaving this here as a placeholder for a more precise assertion later.
-      // (DLD, 10/05.)
-      assert((true || G1CollectedHeap::use_parallel_gc_threads()) ||
-             _g1->evacuation_failed() ||
-             recent_survival_rate <= 1.0, "Or bad frac");
-      return recent_survival_rate;
-  } else {
-    return 1.0; // Be conservative.
-  }
-}
-
-double
-G1CollectorPolicy::last_survival_fraction_work(TruncatedSeq* surviving,
-                                               TruncatedSeq* before) {
-  assert(surviving->num() == before->num(), "Sequence out of sync");
-  if (surviving->num() > 0 && before->last() > 0.0) {
-    double last_survival_rate = surviving->last() / before->last();
-    // We exempt parallel collection from this check because Alloc Buffer
-    // fragmentation can produce negative collections.
-    // Further, we're now always doing parallel collection.  But I'm still
-    // leaving this here as a placeholder for a more precise assertion later.
-    // (DLD, 10/05.)
-    assert((true || G1CollectedHeap::use_parallel_gc_threads()) ||
-           last_survival_rate <= 1.0, "Or bad frac");
-    return last_survival_rate;
-  } else {
-    return 1.0;
-  }
-}
-
-static const int survival_min_obs = 5;
-static double survival_min_obs_limits[] = { 0.9, 0.7, 0.5, 0.3, 0.1 };
-static const double min_survival_rate = 0.1;
-
-double
-G1CollectorPolicy::conservative_avg_survival_fraction_work(double avg,
-                                                           double latest) {
-  double res = avg;
-  if (number_of_recent_gcs() < survival_min_obs) {
-    res = MAX2(res, survival_min_obs_limits[number_of_recent_gcs()]);
-  }
-  res = MAX2(res, latest);
-  res = MAX2(res, min_survival_rate);
-  // In the parallel case, LAB fragmentation can produce "negative
-  // collections"; so can evac failure.  Cap at 1.0
-  res = MIN2(res, 1.0);
-  return res;
-}
-
 size_t G1CollectorPolicy::expansion_amount() {
   double recent_gc_overhead = recent_avg_pause_time_ratio() * 100.0;
   double threshold = _gc_overhead_perc;
@@ -2331,15 +2035,6 @@
         print_summary_sd(0, buffer, &_all_aux_times_ms[i]);
       }
     }
-
-    size_t all_region_num = _region_num_young + _region_num_tenured;
-    gclog_or_tty->print_cr("   New Regions %8d, Young %8d (%6.2lf%%), "
-               "Tenured %8d (%6.2lf%%)",
-               all_region_num,
-               _region_num_young,
-               (double) _region_num_young / (double) all_region_num * 100.0,
-               _region_num_tenured,
-               (double) _region_num_tenured / (double) all_region_num * 100.0);
   }
   if (TraceGen1Time) {
     if (_all_full_gc_times_ms->num() > 0) {
@@ -2361,14 +2056,6 @@
 #endif // PRODUCT
 }
 
-void G1CollectorPolicy::update_region_num(bool young) {
-  if (young) {
-    ++_region_num_young;
-  } else {
-    ++_region_num_tenured;
-  }
-}
-
 #ifndef PRODUCT
 // for debugging, bit of a hack...
 static char*
@@ -2682,8 +2369,7 @@
 }
 
 // Add the heap region at the head of the non-incremental collection set
-void G1CollectorPolicy::
-add_to_collection_set(HeapRegion* hr) {
+void G1CollectorPolicy::add_old_region_to_cset(HeapRegion* hr) {
   assert(_inc_cset_build_state == Active, "Precondition");
   assert(!hr->is_young(), "non-incremental add of young region");
 
@@ -2694,9 +2380,11 @@
   hr->set_in_collection_set(true);
   hr->set_next_in_collection_set(_collection_set);
   _collection_set = hr;
-  _collection_set_size++;
   _collection_set_bytes_used_before += hr->used();
   _g1->register_region_with_in_cset_fast_test(hr);
+  size_t rs_length = hr->rem_set()->occupied();
+  _recorded_rs_lengths += rs_length;
+  _old_cset_region_length += 1;
 }
 
 // Initialize the per-collection-set information
@@ -2705,16 +2393,11 @@
 
   _inc_cset_head = NULL;
   _inc_cset_tail = NULL;
-  _inc_cset_size = 0;
   _inc_cset_bytes_used_before = 0;
 
-  _inc_cset_young_index = 0;
-
   _inc_cset_max_finger = 0;
-  _inc_cset_recorded_young_bytes = 0;
   _inc_cset_recorded_rs_lengths = 0;
   _inc_cset_predicted_elapsed_time_ms = 0;
-  _inc_cset_predicted_bytes_to_copy = 0;
   _inc_cset_build_state = Active;
 }
 
@@ -2745,20 +2428,6 @@
   // rset sampling code
   hr->set_recorded_rs_length(rs_length);
   hr->set_predicted_elapsed_time_ms(region_elapsed_time_ms);
-
-#if PREDICTIONS_VERBOSE
-  size_t bytes_to_copy = predict_bytes_to_copy(hr);
-  _inc_cset_predicted_bytes_to_copy += bytes_to_copy;
-
-  // Record the number of bytes used in this region
-  _inc_cset_recorded_young_bytes += used_bytes;
-
-  // Cache the values we have added to the aggregated informtion
-  // in the heap region in case we have to remove this region from
-  // the incremental collection set, or it is updated by the
-  // rset sampling code
-  hr->set_predicted_bytes_to_copy(bytes_to_copy);
-#endif // PREDICTIONS_VERBOSE
 }
 
 void G1CollectorPolicy::remove_from_incremental_cset_info(HeapRegion* hr) {
@@ -2784,17 +2453,6 @@
   // Clear the values cached in the heap region
   hr->set_recorded_rs_length(0);
   hr->set_predicted_elapsed_time_ms(0);
-
-#if PREDICTIONS_VERBOSE
-  size_t old_predicted_bytes_to_copy = hr->predicted_bytes_to_copy();
-  _inc_cset_predicted_bytes_to_copy -= old_predicted_bytes_to_copy;
-
-  // Subtract the number of bytes used in this region
-  _inc_cset_recorded_young_bytes -= used_bytes;
-
-  // Clear the values cached in the heap region
-  hr->set_predicted_bytes_to_copy(0);
-#endif // PREDICTIONS_VERBOSE
 }
 
 void G1CollectorPolicy::update_incremental_cset_info(HeapRegion* hr, size_t new_rs_length) {
@@ -2806,8 +2464,8 @@
 }
 
 void G1CollectorPolicy::add_region_to_incremental_cset_common(HeapRegion* hr) {
-  assert( hr->is_young(), "invariant");
-  assert( hr->young_index_in_cset() == -1, "invariant" );
+  assert(hr->is_young(), "invariant");
+  assert(hr->young_index_in_cset() > -1, "should have already been set");
   assert(_inc_cset_build_state == Active, "Precondition");
 
   // We need to clear and set the cached recorded/cached collection set
@@ -2827,11 +2485,7 @@
   hr->set_in_collection_set(true);
   assert( hr->next_in_collection_set() == NULL, "invariant");
 
-  _inc_cset_size++;
   _g1->register_region_with_in_cset_fast_test(hr);
-
-  hr->set_young_index_in_cset((int) _inc_cset_young_index);
-  ++_inc_cset_young_index;
 }
 
 // Add the region at the RHS of the incremental cset
@@ -2899,8 +2553,6 @@
 
   YoungList* young_list = _g1->young_list();
 
-  start_recording_regions();
-
   guarantee(target_pause_time_ms > 0.0,
             err_msg("target_pause_time_ms = %1.6lf should be positive",
                     target_pause_time_ms));
@@ -2923,7 +2575,6 @@
   if (time_remaining_ms < threshold) {
     double prev_time_remaining_ms = time_remaining_ms;
     time_remaining_ms = 0.50 * target_pause_time_ms;
-    _within_target = false;
     ergo_verbose3(ErgoCSetConstruction,
                   "adjust remaining time",
                   ergo_format_reason("remaining time lower than threshold")
@@ -2931,8 +2582,6 @@
                   ergo_format_ms("threshold")
                   ergo_format_ms("adjusted remaining time"),
                   prev_time_remaining_ms, threshold, time_remaining_ms);
-  } else {
-    _within_target = true;
   }
 
   size_t expansion_bytes = _g1->expansion_regions() * HeapRegion::GrainBytes;
@@ -2941,8 +2590,6 @@
   double young_start_time_sec = os::elapsedTime();
 
   _collection_set_bytes_used_before = 0;
-  _collection_set_size = 0;
-  _young_cset_length  = 0;
   _last_young_gc_full = full_young_gcs() ? true : false;
 
   if (_last_young_gc_full) {
@@ -2955,9 +2602,9 @@
   // pause are appended to the RHS of the young list, i.e.
   //   [Newly Young Regions ++ Survivors from last pause].
 
-  size_t survivor_region_num = young_list->survivor_length();
-  size_t eden_region_num = young_list->length() - survivor_region_num;
-  size_t old_region_num = 0;
+  size_t survivor_region_length = young_list->survivor_length();
+  size_t eden_region_length = young_list->length() - survivor_region_length;
+  init_cset_region_lengths(eden_region_length, survivor_region_length);
   hr = young_list->first_survivor_region();
   while (hr != NULL) {
     assert(hr->is_survivor(), "badly formed young list");
@@ -2971,9 +2618,7 @@
   if (_g1->mark_in_progress())
     _g1->concurrent_mark()->register_collection_set_finger(_inc_cset_max_finger);
 
-  _young_cset_length = _inc_cset_young_index;
   _collection_set = _inc_cset_head;
-  _collection_set_size = _inc_cset_size;
   _collection_set_bytes_used_before = _inc_cset_bytes_used_before;
   time_remaining_ms -= _inc_cset_predicted_elapsed_time_ms;
   predicted_pause_time_ms += _inc_cset_predicted_elapsed_time_ms;
@@ -2983,19 +2628,12 @@
                 ergo_format_region("eden")
                 ergo_format_region("survivors")
                 ergo_format_ms("predicted young region time"),
-                eden_region_num, survivor_region_num,
+                eden_region_length, survivor_region_length,
                 _inc_cset_predicted_elapsed_time_ms);
 
   // The number of recorded young regions is the incremental
   // collection set's current size
-  set_recorded_young_regions(_inc_cset_size);
   set_recorded_rs_lengths(_inc_cset_recorded_rs_lengths);
-  set_recorded_young_bytes(_inc_cset_recorded_young_bytes);
-#if PREDICTIONS_VERBOSE
-  set_predicted_bytes_to_copy(_inc_cset_predicted_bytes_to_copy);
-#endif // PREDICTIONS_VERBOSE
-
-  assert(_inc_cset_size == young_list->length(), "Invariant");
 
   double young_end_time_sec = os::elapsedTime();
   _recorded_young_cset_choice_time_ms =
@@ -3009,9 +2647,16 @@
     NumberSeq seq;
     double avg_prediction = 100000000000000000.0; // something very large
 
-    size_t prev_collection_set_size = _collection_set_size;
     double prev_predicted_pause_time_ms = predicted_pause_time_ms;
     do {
+      // Note that add_old_region_to_cset() increments the
+      // _old_cset_region_length field and cset_region_length() returns the
+      // sum of _eden_cset_region_length, _survivor_cset_region_length, and
+      // _old_cset_region_length. So, as old regions are added to the
+      // CSet, _old_cset_region_length will be incremented and
+      // cset_region_length(), which is used below, will always reflect
+      // the the total number of regions added up to this point to the CSet.
+
       hr = _collectionSetChooser->getNextMarkedRegion(time_remaining_ms,
                                                       avg_prediction);
       if (hr != NULL) {
@@ -3019,8 +2664,7 @@
         double predicted_time_ms = predict_region_elapsed_time_ms(hr, false);
         time_remaining_ms -= predicted_time_ms;
         predicted_pause_time_ms += predicted_time_ms;
-        add_to_collection_set(hr);
-        record_non_young_cset_region(hr);
+        add_old_region_to_cset(hr);
         seq.add(predicted_time_ms);
         avg_prediction = seq.avg() + seq.sd();
       }
@@ -3041,13 +2685,13 @@
             should_continue = false;
           }
         } else {
-          if (_collection_set_size >= _young_list_fixed_length) {
+          if (cset_region_length() >= _young_list_fixed_length) {
             ergo_verbose2(ErgoCSetConstruction,
                           "stop adding old regions to CSet",
                           ergo_format_reason("CSet length reached target")
                           ergo_format_region("CSet")
                           ergo_format_region("young target"),
-                          _collection_set_size, _young_list_fixed_length);
+                          cset_region_length(), _young_list_fixed_length);
             should_continue = false;
           }
         }
@@ -3055,23 +2699,21 @@
     } while (should_continue);
 
     if (!adaptive_young_list_length() &&
-        _collection_set_size < _young_list_fixed_length) {
+                             cset_region_length() < _young_list_fixed_length) {
       ergo_verbose2(ErgoCSetConstruction,
                     "request partially-young GCs end",
                     ergo_format_reason("CSet length lower than target")
                     ergo_format_region("CSet")
                     ergo_format_region("young target"),
-                    _collection_set_size, _young_list_fixed_length);
+                    cset_region_length(), _young_list_fixed_length);
       _should_revert_to_full_young_gcs  = true;
     }
 
-    old_region_num = _collection_set_size - prev_collection_set_size;
-
     ergo_verbose2(ErgoCSetConstruction | ErgoHigh,
                   "add old regions to CSet",
                   ergo_format_region("old")
                   ergo_format_ms("predicted old region time"),
-                  old_region_num,
+                  old_cset_region_length(),
                   predicted_pause_time_ms - prev_predicted_pause_time_ms);
   }
 
@@ -3079,8 +2721,6 @@
 
   count_CS_bytes_used();
 
-  end_recording_regions();
-
   ergo_verbose5(ErgoCSetConstruction,
                 "finish choosing CSet",
                 ergo_format_region("eden")
@@ -3088,7 +2728,8 @@
                 ergo_format_region("old")
                 ergo_format_ms("predicted pause time")
                 ergo_format_ms("target pause time"),
-                eden_region_num, survivor_region_num, old_region_num,
+                eden_region_length, survivor_region_length,
+                old_cset_region_length(),
                 predicted_pause_time_ms, target_pause_time_ms);
 
   double non_young_end_time_sec = os::elapsedTime();