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_gen_bytes(), 64 _last_allocation_time_s * 1000.0, 65 _last_allocation_time_s > 0.0 ? _old_gen_alloc_tracker->last_period_old_gen_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_gen_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 assert(_last_allocation_time_s > 0, "This should not be called when the last GC is full"); 152 153 return _old_gen_alloc_tracker->last_period_old_gen_growth() / _last_allocation_time_s; 154 } 155 156 void G1AdaptiveIHOPControl::update_allocation_info(double allocation_time_s, 157 size_t additional_buffer_size) { 158 G1IHOPControl::update_allocation_info(allocation_time_s, additional_buffer_size); 159 _allocation_rate_s.add(last_mutator_period_old_allocation_rate()); 160 161 _last_unrestrained_young_size = additional_buffer_size; 162 } 163 164 void G1AdaptiveIHOPControl::update_marking_length(double marking_length_s) { 165 assert(marking_length_s >= 0.0, "Marking length must be larger than zero but is %.3f", marking_length_s); 166 _marking_times_s.add(marking_length_s); 167 } 168 169 void G1AdaptiveIHOPControl::print() { 170 G1IHOPControl::print(); 171 size_t actual_target = actual_target_threshold(); 172 log_debug(gc, ihop)("Adaptive IHOP information (value update), threshold: " SIZE_FORMAT "B (%1.2f), internal target occupancy: " SIZE_FORMAT "B, " 173 "occupancy: " SIZE_FORMAT "B, additional buffer size: " SIZE_FORMAT "B, predicted old gen allocation rate: %1.2fB/s, " 174 "predicted marking phase length: %1.2fms, prediction active: %s", 175 get_conc_mark_start_threshold(), 176 percent_of(get_conc_mark_start_threshold(), actual_target), 177 actual_target, 178 G1CollectedHeap::heap()->used(), 179 _last_unrestrained_young_size, 180 predict(&_allocation_rate_s), 181 predict(&_marking_times_s) * 1000.0, 182 have_enough_data_for_prediction() ? "true" : "false"); 183 } 184 185 void G1AdaptiveIHOPControl::send_trace_event(G1NewTracer* tracer) { 186 G1IHOPControl::send_trace_event(tracer); 187 tracer->report_adaptive_ihop_statistics(get_conc_mark_start_threshold(), 188 actual_target_threshold(), 189 G1CollectedHeap::heap()->used(), 190 _last_unrestrained_young_size, 191 predict(&_allocation_rate_s), 192 predict(&_marking_times_s), 193 have_enough_data_for_prediction()); 194 }