rev 60542 : [mq]: 8245511-rev.3

   1 /*
   2  * Copyright (c) 2015, 2020, Oracle and/or its affiliates. All rights reserved.
   3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   4  *
   5  * This code is free software; you can redistribute it and/or modify it
   6  * under the terms of the GNU General Public License version 2 only, as
   7  * published by the Free Software Foundation.
   8  *
   9  * This code is distributed in the hope that it will be useful, but WITHOUT
  10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  12  * version 2 for more details (a copy is included in the LICENSE file that
  13  * accompanied this code).
  14  *
  15  * You should have received a copy of the GNU General Public License version
  16  * 2 along with this work; if not, write to the Free Software Foundation,
  17  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  18  *
  19  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  20  * or visit www.oracle.com if you need additional information or have any
  21  * questions.
  22  *
  23  */
  24 
  25 #include "precompiled.hpp"
  26 #include "gc/g1/g1CollectedHeap.inline.hpp"
  27 #include "gc/g1/g1IHOPControl.hpp"
  28 #include "gc/g1/g1Predictions.hpp"
  29 #include "gc/g1/g1Trace.hpp"
  30 #include "logging/log.hpp"
  31 
  32 G1IHOPControl::G1IHOPControl(double initial_ihop_percent,
  33                              G1OldGenAllocationTracker const* old_gen_alloc_tracker) :
  34   _initial_ihop_percent(initial_ihop_percent),
  35   _target_occupancy(0),
  36   _last_allocation_time_s(0.0),
  37   _old_gen_alloc_tracker(old_gen_alloc_tracker)
  38 {
  39   assert(_initial_ihop_percent >= 0.0 && _initial_ihop_percent <= 100.0, "Initial IHOP value must be between 0 and 100 but is %.3f", initial_ihop_percent);
  40 }
  41 
  42 void G1IHOPControl::update_target_occupancy(size_t new_target_occupancy) {
  43   log_debug(gc, ihop)("Target occupancy update: old: " SIZE_FORMAT "B, new: " SIZE_FORMAT "B",
  44                       _target_occupancy, new_target_occupancy);
  45   _target_occupancy = new_target_occupancy;
  46 }
  47 
  48 void G1IHOPControl::update_allocation_info(double allocation_time_s, size_t additional_buffer_size) {
  49   assert(allocation_time_s >= 0.0, "Allocation time must be positive but is %.3f", allocation_time_s);
  50 
  51   _last_allocation_time_s = allocation_time_s;
  52 }
  53 
  54 void G1IHOPControl::print() {
  55   assert(_target_occupancy > 0, "Target occupancy still not updated yet.");
  56   size_t cur_conc_mark_start_threshold = get_conc_mark_start_threshold();
  57   log_debug(gc, ihop)("Basic information (value update), threshold: " SIZE_FORMAT "B (%1.2f), target occupancy: " SIZE_FORMAT "B, current occupancy: " SIZE_FORMAT "B, "
  58                       "recent allocation size: " SIZE_FORMAT "B, recent allocation duration: %1.2fms, recent old gen allocation rate: %1.2fB/s, recent marking phase length: %1.2fms",
  59                       cur_conc_mark_start_threshold,
  60                       percent_of(cur_conc_mark_start_threshold, _target_occupancy),
  61                       _target_occupancy,
  62                       G1CollectedHeap::heap()->used(),
  63                       _old_gen_alloc_tracker->last_period_old_bytes(),
  64                       _last_allocation_time_s * 1000.0,
  65                       _last_allocation_time_s > 0.0 ? _old_gen_alloc_tracker->last_period_old_bytes() / _last_allocation_time_s : 0.0,
  66                       last_marking_length_s() * 1000.0);
  67 }
  68 
  69 void G1IHOPControl::send_trace_event(G1NewTracer* tracer) {
  70   assert(_target_occupancy > 0, "Target occupancy still not updated yet.");
  71   tracer->report_basic_ihop_statistics(get_conc_mark_start_threshold(),
  72                                        _target_occupancy,
  73                                        G1CollectedHeap::heap()->used(),
  74                                        _old_gen_alloc_tracker->last_period_old_bytes(),
  75                                        _last_allocation_time_s,
  76                                        last_marking_length_s());
  77 }
  78 
  79 G1StaticIHOPControl::G1StaticIHOPControl(double ihop_percent,
  80                                          G1OldGenAllocationTracker const* old_gen_alloc_tracker) :
  81   G1IHOPControl(ihop_percent, old_gen_alloc_tracker),
  82   _last_marking_length_s(0.0) {
  83 }
  84 
  85 G1AdaptiveIHOPControl::G1AdaptiveIHOPControl(double ihop_percent,
  86                                              G1OldGenAllocationTracker const* old_gen_alloc_tracker,
  87                                              G1Predictions const* predictor,
  88                                              size_t heap_reserve_percent,
  89                                              size_t heap_waste_percent) :
  90   G1IHOPControl(ihop_percent, old_gen_alloc_tracker),
  91   _heap_reserve_percent(heap_reserve_percent),
  92   _heap_waste_percent(heap_waste_percent),
  93   _predictor(predictor),
  94   _marking_times_s(10, 0.95),
  95   _allocation_rate_s(10, 0.95),
  96   _last_unrestrained_young_size(0)
  97 {
  98 }
  99 
 100 size_t G1AdaptiveIHOPControl::actual_target_threshold() const {
 101   guarantee(_target_occupancy > 0, "Target occupancy still not updated yet.");
 102   // The actual target threshold takes the heap reserve and the expected waste in
 103   // free space  into account.
 104   // _heap_reserve is that part of the total heap capacity that is reserved for
 105   // eventual promotion failure.
 106   // _heap_waste is the amount of space will never be reclaimed in any
 107   // heap, so can not be used for allocation during marking and must always be
 108   // considered.
 109 
 110   double safe_total_heap_percentage = MIN2((double)(_heap_reserve_percent + _heap_waste_percent), 100.0);
 111 
 112   return (size_t)MIN2(
 113     G1CollectedHeap::heap()->max_capacity() * (100.0 - safe_total_heap_percentage) / 100.0,
 114     _target_occupancy * (100.0 - _heap_waste_percent) / 100.0
 115     );
 116 }
 117 
 118 double G1AdaptiveIHOPControl::predict(TruncatedSeq const* seq) const {
 119   return _predictor->predict_zero_bounded(seq);
 120 }
 121 
 122 bool G1AdaptiveIHOPControl::have_enough_data_for_prediction() const {
 123   return ((size_t)_marking_times_s.num() >= G1AdaptiveIHOPNumInitialSamples) &&
 124          ((size_t)_allocation_rate_s.num() >= G1AdaptiveIHOPNumInitialSamples);
 125 }
 126 
 127 size_t G1AdaptiveIHOPControl::get_conc_mark_start_threshold() {
 128   if (have_enough_data_for_prediction()) {
 129     double pred_marking_time = predict(&_marking_times_s);
 130     double pred_promotion_rate = predict(&_allocation_rate_s);
 131     size_t pred_promotion_size = (size_t)(pred_marking_time * pred_promotion_rate);
 132 
 133     size_t predicted_needed_bytes_during_marking =
 134       pred_promotion_size +
 135       // In reality we would need the maximum size of the young gen during
 136       // marking. This is a conservative estimate.
 137       _last_unrestrained_young_size;
 138 
 139     size_t internal_threshold = actual_target_threshold();
 140     size_t predicted_initiating_threshold = predicted_needed_bytes_during_marking < internal_threshold ?
 141                                             internal_threshold - predicted_needed_bytes_during_marking :
 142                                             0;
 143     return predicted_initiating_threshold;
 144   } else {
 145     // Use the initial value.
 146     return (size_t)(_initial_ihop_percent * _target_occupancy / 100.0);
 147   }
 148 }
 149 
 150 double G1AdaptiveIHOPControl::last_mutator_period_old_allocation_rate() const {
 151   // The upper limit of the freed region count is the number of regions allocated
 152   // since the last gc. When more humongous regions survived the current gc than
 153   // survived the previous one, deduct the increment.
 154   assert(_last_allocation_time_s > 0, "This should not be called when the last GC is full");
 155   size_t freed_humongous_bytes = _old_gen_alloc_tracker->_last_period_humongous_bytes;
 156   size_t humongous_bytes_after_penultimate_gc = _old_gen_alloc_tracker->_humongous_bytes_after_penultimate_gc;
 157   size_t humongous_bytes_after_last_gc = _old_gen_alloc_tracker->_humongous_bytes_after_last_gc;
 158   size_t last_period_old_bytes = _old_gen_alloc_tracker->last_period_old_bytes();
 159 
 160   if (freed_humongous_bytes > 0 && humongous_bytes_after_penultimate_gc < humongous_bytes_after_last_gc) {
 161     freed_humongous_bytes -= humongous_bytes_after_last_gc - humongous_bytes_after_penultimate_gc;
 162   }
 163   assert(last_period_old_bytes >= freed_humongous_bytes, "Allocation rate cannot be negative");
 164   return (last_period_old_bytes - freed_humongous_bytes) / _last_allocation_time_s;
 165  }
 166 
 167 void G1AdaptiveIHOPControl::update_allocation_info(double allocation_time_s,
 168                                                    size_t additional_buffer_size) {
 169   G1IHOPControl::update_allocation_info(allocation_time_s, additional_buffer_size);
 170   _allocation_rate_s.add(last_mutator_period_old_allocation_rate());
 171 
 172   _last_unrestrained_young_size = additional_buffer_size;
 173 }
 174 
 175 void G1AdaptiveIHOPControl::update_marking_length(double marking_length_s) {
 176    assert(marking_length_s >= 0.0, "Marking length must be larger than zero but is %.3f", marking_length_s);
 177   _marking_times_s.add(marking_length_s);
 178 }
 179 
 180 void G1AdaptiveIHOPControl::print() {
 181   G1IHOPControl::print();
 182   size_t actual_target = actual_target_threshold();
 183   log_debug(gc, ihop)("Adaptive IHOP information (value update), threshold: " SIZE_FORMAT "B (%1.2f), internal target occupancy: " SIZE_FORMAT "B, "
 184                       "occupancy: " SIZE_FORMAT "B, additional buffer size: " SIZE_FORMAT "B, predicted old gen allocation rate: %1.2fB/s, "
 185                       "predicted marking phase length: %1.2fms, prediction active: %s",
 186                       get_conc_mark_start_threshold(),
 187                       percent_of(get_conc_mark_start_threshold(), actual_target),
 188                       actual_target,
 189                       G1CollectedHeap::heap()->used(),
 190                       _last_unrestrained_young_size,
 191                       predict(&_allocation_rate_s),
 192                       predict(&_marking_times_s) * 1000.0,
 193                       have_enough_data_for_prediction() ? "true" : "false");
 194 }
 195 
 196 void G1AdaptiveIHOPControl::send_trace_event(G1NewTracer* tracer) {
 197   G1IHOPControl::send_trace_event(tracer);
 198   tracer->report_adaptive_ihop_statistics(get_conc_mark_start_threshold(),
 199                                           actual_target_threshold(),
 200                                           G1CollectedHeap::heap()->used(),
 201                                           _last_unrestrained_young_size,
 202                                           predict(&_allocation_rate_s),
 203                                           predict(&_marking_times_s),
 204                                           have_enough_data_for_prediction());
 205 }
--- EOF ---