rev 9282 : dihop-changes
rev 9283 : imported patch sihop-thomas-review
rev 9284 : imported patch 8136678-implement-adaptive-sizing-algorithm-for-IHOP
rev 9285 : imported patch aihop-thomas-review
rev 9286 : imported patch 8136679-jfr-event-for-dynamic-ihop

   1 /*
   2  * Copyright (c) 2015, 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/g1ErgoVerbose.hpp"
  28 #include "gc/g1/g1IHOPControl.hpp"
  29 #include "gc/g1/g1Predictions.hpp"

  30 
  31 G1IHOPControl::G1IHOPControl(double initial_ihop_percent, size_t target_occupancy) :
  32   _ihop_percent(initial_ihop_percent),
  33   _target_occupancy(target_occupancy) {
  34   assert(_ihop_percent >= 0.0 && _ihop_percent <= 100.0, "Initial IHOP value must be between 0 and 100 but is %.3f", initial_ihop_percent);
  35 }
  36 
  37 G1StaticIHOPControl::G1StaticIHOPControl(double ihop_percent, size_t target_occupancy) :
  38   G1IHOPControl(ihop_percent, target_occupancy),
  39   _last_allocation_time_s(0.0),
  40   _last_allocated_bytes(0),
  41   _last_marking_length_s(0.0) {
  42   assert(_target_occupancy > 0, "Target occupancy must be larger than zero.");
  43 }
  44 
  45 void G1StaticIHOPControl::print() {
  46   ergo_verbose6(ErgoIHOP,
  47                 "basic information",
  48                 ergo_format_reason("value update")
  49                 ergo_format_byte_perc("threshold")
  50                 ergo_format_byte("target occupancy")
  51                 ergo_format_byte("current occupancy")
  52                 ergo_format_double("recent old gen allocation rate")
  53                 ergo_format_ms("recent marking phase length"),
  54                 get_conc_mark_start_threshold(),
  55                 (double) get_conc_mark_start_threshold() / _target_occupancy * 100.0,
  56                 _target_occupancy,
  57                 G1CollectedHeap::heap()->used(),
  58                 _last_allocation_time_s > 0.0 ? _last_allocated_bytes / _last_allocation_time_s : 0.0,
  59                 _last_marking_length_s * 1000.0);
  60 }
  61 









  62 #ifndef PRODUCT
  63 static void test_update(G1IHOPControl* ctrl, double alloc_time, size_t alloc_amount, size_t young_size, double mark_time) {
  64   for (int i = 0; i < 100; i++) {
  65     ctrl->update_allocation_info(alloc_time, alloc_amount, young_size);
  66     ctrl->update_time_to_mixed(mark_time);
  67   }
  68 }
  69 
  70 void G1StaticIHOPControl::test() {
  71   size_t const initial_ihop = 45;
  72 
  73   G1StaticIHOPControl ctrl(initial_ihop, 100);
  74   size_t threshold;
  75   
  76   threshold = ctrl.get_conc_mark_start_threshold();
  77   assert(threshold == initial_ihop,
  78          "Expected IHOP threshold of " SIZE_FORMAT " but is " SIZE_FORMAT, initial_ihop, threshold);
  79 
  80   ctrl.update_allocation_info(100.0, 100, 100);
  81   threshold = ctrl.get_conc_mark_start_threshold();
  82   assert(threshold == initial_ihop,
  83          "Expected IHOP threshold of " SIZE_FORMAT " but is " SIZE_FORMAT, initial_ihop, threshold);
  84 
  85   ctrl.update_time_to_mixed(1000.0);
  86   threshold = ctrl.get_conc_mark_start_threshold();
  87   assert(threshold == initial_ihop,
  88          "Expected IHOP threshold of " SIZE_FORMAT " but is " SIZE_FORMAT, initial_ihop, threshold);
  89 
  90   // Whatever we pass, the IHOP value must stay the same.
  91   test_update(&ctrl, 2, 10, 10, 3);
  92   threshold = ctrl.get_conc_mark_start_threshold();
  93   assert(threshold == initial_ihop,
  94          "Expected IHOP threshold of " SIZE_FORMAT " but is " SIZE_FORMAT, initial_ihop, threshold);
  95 
  96   test_update(&ctrl, 12, 10, 10, 3);
  97   threshold = ctrl.get_conc_mark_start_threshold();
  98   assert(threshold == initial_ihop,
  99          "Expected IHOP threshold of " SIZE_FORMAT " but is " SIZE_FORMAT, initial_ihop, threshold);
 100 }
 101 #endif
 102 
 103 G1AdaptiveIHOPControl::G1AdaptiveIHOPControl(double ihop_percent, size_t initial_target_occupancy, G1Predictions const* predictor) :
 104   G1IHOPControl(ihop_percent, initial_target_occupancy),
 105   _predictor(predictor),
 106   _marking_times_s(10, 0.95),
 107   _allocation_rate_s(10, 0.95),
 108   _prev_unrestrained_young_size(0),
 109   _current_threshold(0.0)
 110 {
 111   recalculate();
 112 }
 113 
 114 void G1AdaptiveIHOPControl::recalculate() {
 115   if (have_enough_data_for_prediction()) {
 116     double pred_marking_time = _predictor->get_new_prediction(&_marking_times_s);
 117     double pred_promotion_rate = _predictor->get_new_prediction(&_allocation_rate_s);
 118 
 119     size_t predicted_needed_bytes_during_marking =
 120       (pred_marking_time * pred_promotion_rate +
 121        _prev_unrestrained_young_size); // In reality we would need the size of the young gen of the first mixed GC. This is a conservative estimate.
 122     size_t predicted_initiating_threshold = predicted_needed_bytes_during_marking < _target_occupancy ?
 123                                             _target_occupancy - predicted_needed_bytes_during_marking :
 124                                             0;
 125     _current_threshold = predicted_initiating_threshold;
 126   } else {
 127     // Use the initial value.
 128     _current_threshold = _ihop_percent * _target_occupancy / 100.0;  
 129   }
 130 }
 131 
 132 bool G1AdaptiveIHOPControl::have_enough_data_for_prediction() const {
 133   return (_marking_times_s.num() > 2) && (_allocation_rate_s.num() > 2);
 134 }
 135 
 136 void G1AdaptiveIHOPControl::set_target_occupancy(size_t target_occupancy) {
 137   _target_occupancy = target_occupancy;
 138 }
 139 
 140 size_t G1AdaptiveIHOPControl::get_conc_mark_start_threshold() {
 141   recalculate();
 142   return _current_threshold;
 143 }
 144 
 145 void G1AdaptiveIHOPControl::update_allocation_info(double allocation_time_s, size_t allocated_bytes, size_t additional_buffer_size) {
 146   assert(allocation_time_s >= 0.0, "Allocation time must be positive but is %.3f", allocation_time_s);
 147   double allocation_rate = (double) allocated_bytes / allocation_time_s;
 148   _allocation_rate_s.add(allocation_rate);
 149 
 150   _last_allocation_bytes = allocated_bytes;
 151   _prev_unrestrained_young_size = additional_buffer_size;
 152 }
 153 
 154 void G1AdaptiveIHOPControl::update_time_to_mixed(double marking_length_s) {
 155    assert(marking_length_s >= 0.0, "Marking length must be larger than zero but is %.3f", marking_length_s);
 156   _marking_times_s.add(marking_length_s);
 157 }
 158 
 159 void G1AdaptiveIHOPControl::print() {
 160   ergo_verbose6(ErgoIHOP,
 161                 "basic information",
 162                 ergo_format_reason("value update")
 163                 ergo_format_byte_perc("threshold")
 164                 ergo_format_byte("target threshold")
 165                 ergo_format_byte("current occupancy")
 166                 ergo_format_double("recent old gen allocation rate")
 167                 ergo_format_double("recent marking phase length"),
 168                 get_conc_mark_start_threshold(),
 169                 _target_occupancy > 0 ? (double) get_conc_mark_start_threshold() / _target_occupancy * 100.0 : 0.0,
 170                 _target_occupancy,
 171                 G1CollectedHeap::heap()->used(),
 172                 _allocation_rate_s.last(),
 173                 _marking_times_s.last()
 174                 );
 175   ergo_verbose3(ErgoIHOP, 
 176                 "adaptive IHOP information",
 177                 ergo_format_reason("value update")
 178                 ergo_format_double("predicted old gen allocation rate")
 179                 ergo_format_double("predicted marking phase length")
 180                 ergo_format_str("prediction active"),
 181                 _predictor->get_new_prediction(&_allocation_rate_s),
 182                 _predictor->get_new_prediction(&_marking_times_s),
 183                 have_enough_data_for_prediction() ? "true" : "false"
 184                 );













 185 }
 186 
 187 #ifndef PRODUCT
 188 void G1AdaptiveIHOPControl::test() {
 189   size_t const initial_threshold = 45;
 190   size_t const young_size = 10;
 191   size_t const target_size = 100;
 192 
 193   // The final IHOP value is always
 194   // target_size - (young_size + alloc_amount/alloc_time * marking_time)
 195 
 196   G1Predictions pred(0.95);
 197   G1AdaptiveIHOPControl ctrl(initial_threshold, target_size, &pred);
 198 
 199   // First "load".
 200   size_t const alloc_time1 = 2;
 201   size_t const alloc_amount1 = 10;
 202   size_t const marking_time1 = 2;
 203   size_t const settled_ihop1 = target_size - (young_size + alloc_amount1/alloc_time1 * marking_time1);
 204 
 205   size_t threshold;
 206   threshold = ctrl.get_conc_mark_start_threshold();
 207   assert(threshold == initial_threshold,
 208          "Expected IHOP threshold of " SIZE_FORMAT " but is " SIZE_FORMAT, initial_threshold, threshold);
 209   ctrl.update_allocation_info(alloc_time1, alloc_amount1, young_size);
 210   ctrl.update_time_to_mixed(marking_time1);
 211   // Not enough data yet.
 212   threshold = ctrl.get_conc_mark_start_threshold();
 213   assert(threshold == initial_threshold,
 214          "Expected IHOP threshold of " SIZE_FORMAT " but is " SIZE_FORMAT, initial_threshold, threshold);
 215   // Not enough data yet.
 216   ctrl.update_allocation_info(alloc_time1, alloc_amount1, young_size);
 217   ctrl.update_time_to_mixed(marking_time1);
 218   threshold = ctrl.get_conc_mark_start_threshold();
 219   assert(threshold == initial_threshold,
 220          "Expected IHOP threshold of " SIZE_FORMAT " but is " SIZE_FORMAT, initial_threshold, threshold);
 221  
 222   test_update(&ctrl, alloc_time1, alloc_amount1, young_size, marking_time1);
 223   
 224   threshold = ctrl.get_conc_mark_start_threshold();
 225   assert(threshold == settled_ihop1,
 226          "Expected IHOP threshold to settle at " SIZE_FORMAT " but is " SIZE_FORMAT, settled_ihop1, threshold);
 227 
 228   // Second "load". A bit higher allocation rate.
 229   size_t const alloc_time2 = 2;
 230   size_t const alloc_amount2 = 30;
 231   size_t const marking_time2 = 2;
 232   size_t const settled_ihop2 = target_size - (young_size + alloc_amount2/alloc_time2 * marking_time2);
 233 
 234   test_update(&ctrl, alloc_time2, alloc_amount2, young_size, marking_time2);
 235 
 236   threshold = ctrl.get_conc_mark_start_threshold();
 237   assert(threshold < settled_ihop1,
 238          "Expected IHOP threshold to settle at a value lower than " SIZE_FORMAT " but is " SIZE_FORMAT, settled_ihop1, threshold);
 239 
 240   // Third "load". Very high (impossible) allocation rate.
 241   size_t const alloc_time3 = 1;
 242   size_t const alloc_amount3 = 50;
 243   size_t const marking_time3 = 2;
 244   size_t const settled_ihop3 = 0; // target_size - (young_size + alloc_amount2/alloc_time2 * marking_time2);
 245 
 246   test_update(&ctrl, alloc_time3, alloc_amount3, young_size, marking_time3);
 247   threshold = ctrl.get_conc_mark_start_threshold();
 248 
 249   assert(threshold == settled_ihop3,
 250          "Expected IHOP threshold to settle at " SIZE_FORMAT " but is " SIZE_FORMAT, settled_ihop3, threshold);
 251 
 252   // And back to some arbitrary value.
 253   test_update(&ctrl, alloc_time2, alloc_amount2, young_size, marking_time2);
 254 
 255   threshold = ctrl.get_conc_mark_start_threshold();
 256   assert(threshold > settled_ihop3,
 257          "Expected IHOP threshold to settle at value larger than " SIZE_FORMAT " but is " SIZE_FORMAT, settled_ihop3, threshold);
 258 }
 259 
 260 void IHOP_test() {
 261   G1StaticIHOPControl::test();
 262   G1AdaptiveIHOPControl::test();  
 263 }
 264 #endif
--- EOF ---