1 /*
2 * Copyright (c) 1997, 2021, 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/shared/ageTable.inline.hpp"
27 #include "gc/shared/ageTableTracer.hpp"
28 #include "gc/shared/collectedHeap.hpp"
29 #include "gc/shared/gc_globals.hpp"
30 #include "jvm.h"
31 #include "logging/log.hpp"
32 #include "memory/resourceArea.hpp"
33 #include "oops/oop.inline.hpp"
34 #include "runtime/perfData.hpp"
35 #include "utilities/copy.hpp"
36 #include "logging/logStream.hpp"
37
38 /* Copyright (c) 1992, 2021, Oracle and/or its affiliates, and Stanford University.
39 See the LICENSE file for license information. */
40
41 AgeTable::AgeTable(bool global) : _use_perf_data(UsePerfData && global) {
42
43 clear();
44
45 if (_use_perf_data) {
46
47 ResourceMark rm;
48 EXCEPTION_MARK;
49
50 const char* agetable_ns = "generation.0.agetable";
51 const char* bytes_ns = PerfDataManager::name_space(agetable_ns, "bytes");
52
53 for(int age = 0; age < table_size; age ++) {
54 char age_name[10];
55 jio_snprintf(age_name, sizeof(age_name), "%2.2d", age);
56 const char* cname = PerfDataManager::counter_name(bytes_ns, age_name);
57 _perf_sizes[age] = PerfDataManager::create_variable(SUN_GC, cname,
58 PerfData::U_Bytes,
59 CHECK);
60 }
61
62 const char* cname = PerfDataManager::counter_name(agetable_ns, "size");
63 PerfDataManager::create_constant(SUN_GC, cname, PerfData::U_None,
64 table_size, CHECK);
65 }
66 }
67
68 void AgeTable::clear() {
69 for (size_t* p = sizes; p < sizes + table_size; ++p) {
70 *p = 0;
71 }
72 }
73
74 #ifndef PRODUCT
75 bool AgeTable::is_clear() {
76 size_t total = 0;
77 for (size_t* p = sizes; p < sizes + table_size; ++p) {
78 total += *p;
79 }
80 return total == 0;
81 }
82 #endif // !PRODUCT
83
84 void AgeTable::merge(const AgeTable* subTable) {
85 for (int i = 0; i < table_size; i++) {
86 sizes[i]+= subTable->sizes[i];
87 }
88 }
89
90 uint AgeTable::compute_tenuring_threshold(size_t desired_survivor_size) {
91 uint result;
92
93 if (AlwaysTenure || NeverTenure) {
94 assert(MaxTenuringThreshold == 0 || MaxTenuringThreshold == markWord::max_age + 1,
95 "MaxTenuringThreshold should be 0 or markWord::max_age + 1, but is %u", MaxTenuringThreshold);
96 result = MaxTenuringThreshold;
97 } else {
98 size_t total = 0;
99 uint age = 1;
100 assert(sizes[0] == 0, "no objects with age zero should be recorded");
101 while (age < table_size) {
102 total += sizes[age];
103 // check if including objects of age 'age' made us pass the desired
104 // size, if so 'age' is the new threshold
105 if (total > desired_survivor_size) break;
106 age++;
107 }
108 result = age < MaxTenuringThreshold ? age : MaxTenuringThreshold;
109 }
110
111
112 log_debug(gc, age)("Desired survivor size %zu bytes, new threshold " UINTX_FORMAT " (max threshold %u)",
113 desired_survivor_size * oopSize, (uintx) result, MaxTenuringThreshold);
114
115 return result;
116 }
117
118 void AgeTable::print_age_table(uint tenuring_threshold) {
119 LogTarget(Trace, gc, age) lt;
120 if (lt.is_enabled() || _use_perf_data || AgeTableTracer::is_tenuring_distribution_event_enabled()) {
121 LogStream st(lt);
122 print_on(&st, tenuring_threshold);
123 }
124 }
125
126 void AgeTable::print_on(outputStream* st, uint tenuring_threshold) {
127 st->print_cr("Age table with threshold %u (max threshold %u)",
128 tenuring_threshold, MaxTenuringThreshold);
129
130 size_t total = 0;
131 uint age = 1;
132 while (age < table_size) {
133 size_t word_size = sizes[age];
134 total += word_size;
135 if (word_size > 0) {
136 st->print_cr("- age %3u: " SIZE_FORMAT_W(10) " bytes, " SIZE_FORMAT_W(10) " total",
137 age, word_size * oopSize, total * oopSize);
138 }
139 AgeTableTracer::send_tenuring_distribution_event(age, word_size * oopSize);
140 if (_use_perf_data) {
141 _perf_sizes[age]->set_value(word_size * oopSize);
142 }
143 age++;
144 }
145 }