1/*
2 * Copyright (c) 2015, 2017, 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/shared/gcTrace.hpp"
30#include "logging/log.hpp"
31
32G1IHOPControl::G1IHOPControl(double initial_ihop_percent) :
33 _initial_ihop_percent(initial_ihop_percent),
34 _target_occupancy(0),
35 _last_allocation_time_s(0.0),
36 _last_allocated_bytes(0)
37{
38 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);
39}
40
41void G1IHOPControl::update_target_occupancy(size_t new_target_occupancy) {
42 log_debug(gc, ihop)("Target occupancy update: old: " SIZE_FORMAT "B, new: " SIZE_FORMAT "B",
43 _target_occupancy, new_target_occupancy);
44 _target_occupancy = new_target_occupancy;
45}
46
47void G1IHOPControl::update_allocation_info(double allocation_time_s, size_t allocated_bytes, size_t additional_buffer_size) {
48 assert(allocation_time_s >= 0.0, "Allocation time must be positive but is %.3f", allocation_time_s);
49
50 _last_allocation_time_s = allocation_time_s;
51 _last_allocated_bytes = allocated_bytes;
52}
53
54void 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 _last_allocated_bytes,
64 _last_allocation_time_s * 1000.0,
65 _last_allocation_time_s > 0.0 ? _last_allocated_bytes / _last_allocation_time_s : 0.0,
66 last_marking_length_s() * 1000.0);
67}
68
69void 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 _last_allocated_bytes,
75 _last_allocation_time_s,
76 last_marking_length_s());
77}
78
79G1StaticIHOPControl::G1StaticIHOPControl(double ihop_percent) :
80 G1IHOPControl(ihop_percent),
81 _last_marking_length_s(0.0) {
82}
83
84G1AdaptiveIHOPControl::G1AdaptiveIHOPControl(double ihop_percent,
85 G1Predictions const* predictor,
86 size_t heap_reserve_percent,
87 size_t heap_waste_percent) :
88 G1IHOPControl(ihop_percent),
89 _heap_reserve_percent(heap_reserve_percent),
90 _heap_waste_percent(heap_waste_percent),
91 _predictor(predictor),
92 _marking_times_s(10, 0.95),
93 _allocation_rate_s(10, 0.95),
94 _last_unrestrained_young_size(0)
95{
96}
97
98size_t G1AdaptiveIHOPControl::actual_target_threshold() const {
99 guarantee(_target_occupancy > 0, "Target occupancy still not updated yet.");
100 // The actual target threshold takes the heap reserve and the expected waste in
101 // free space into account.
102 // _heap_reserve is that part of the total heap capacity that is reserved for
103 // eventual promotion failure.
104 // _heap_waste is the amount of space will never be reclaimed in any
105 // heap, so can not be used for allocation during marking and must always be
106 // considered.
107
108 double safe_total_heap_percentage = MIN2((double)(_heap_reserve_percent + _heap_waste_percent), 100.0);
109
110 return (size_t)MIN2(
111 G1CollectedHeap::heap()->max_capacity() * (100.0 - safe_total_heap_percentage) / 100.0,
112 _target_occupancy * (100.0 - _heap_waste_percent) / 100.0
113 );
114}
115
116bool G1AdaptiveIHOPControl::have_enough_data_for_prediction() const {
117 return ((size_t)_marking_times_s.num() >= G1AdaptiveIHOPNumInitialSamples) &&
118 ((size_t)_allocation_rate_s.num() >= G1AdaptiveIHOPNumInitialSamples);
119}
120
121size_t G1AdaptiveIHOPControl::get_conc_mark_start_threshold() {
122 if (have_enough_data_for_prediction()) {
123 double pred_marking_time = _predictor->get_new_prediction(&_marking_times_s);
124 double pred_promotion_rate = _predictor->get_new_prediction(&_allocation_rate_s);
125 size_t pred_promotion_size = (size_t)(pred_marking_time * pred_promotion_rate);
126
127 size_t predicted_needed_bytes_during_marking =
128 pred_promotion_size +
129 // In reality we would need the maximum size of the young gen during
130 // marking. This is a conservative estimate.
131 _last_unrestrained_young_size;
132
133 size_t internal_threshold = actual_target_threshold();
134 size_t predicted_initiating_threshold = predicted_needed_bytes_during_marking < internal_threshold ?
135 internal_threshold - predicted_needed_bytes_during_marking :
136 0;
137 return predicted_initiating_threshold;
138 } else {
139 // Use the initial value.
140 return (size_t)(_initial_ihop_percent * _target_occupancy / 100.0);
141 }
142}
143
144void G1AdaptiveIHOPControl::update_allocation_info(double allocation_time_s,
145 size_t allocated_bytes,
146 size_t additional_buffer_size) {
147 G1IHOPControl::update_allocation_info(allocation_time_s, allocated_bytes, additional_buffer_size);
148
149 double allocation_rate = (double) allocated_bytes / allocation_time_s;
150 _allocation_rate_s.add(allocation_rate);
151
152 _last_unrestrained_young_size = additional_buffer_size;
153}
154
155void G1AdaptiveIHOPControl::update_marking_length(double marking_length_s) {
156 assert(marking_length_s >= 0.0, "Marking length must be larger than zero but is %.3f", marking_length_s);
157 _marking_times_s.add(marking_length_s);
158}
159
160void G1AdaptiveIHOPControl::print() {
161 G1IHOPControl::print();
162 size_t actual_target = actual_target_threshold();
163 log_debug(gc, ihop)("Adaptive IHOP information (value update), threshold: " SIZE_FORMAT "B (%1.2f), internal target occupancy: " SIZE_FORMAT "B, "
164 "occupancy: " SIZE_FORMAT "B, additional buffer size: " SIZE_FORMAT "B, predicted old gen allocation rate: %1.2fB/s, "
165 "predicted marking phase length: %1.2fms, prediction active: %s",
166 get_conc_mark_start_threshold(),
167 percent_of(get_conc_mark_start_threshold(), actual_target),
168 actual_target,
169 G1CollectedHeap::heap()->used(),
170 _last_unrestrained_young_size,
171 _predictor->get_new_prediction(&_allocation_rate_s),
172 _predictor->get_new_prediction(&_marking_times_s) * 1000.0,
173 have_enough_data_for_prediction() ? "true" : "false");
174}
175
176void G1AdaptiveIHOPControl::send_trace_event(G1NewTracer* tracer) {
177 G1IHOPControl::send_trace_event(tracer);
178 tracer->report_adaptive_ihop_statistics(get_conc_mark_start_threshold(),
179 actual_target_threshold(),
180 G1CollectedHeap::heap()->used(),
181 _last_unrestrained_young_size,
182 _predictor->get_new_prediction(&_allocation_rate_s),
183 _predictor->get_new_prediction(&_marking_times_s),
184 have_enough_data_for_prediction());
185}
186