1 /*
2 * Copyright (c) 1997, 2014, 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_implementation/shared/ageTable.hpp"
27 #include "gc_implementation/shared/ageTableTracer.hpp"
28 #include "gc_implementation/shared/gcPolicyCounters.hpp"
29 #include "memory/collectorPolicy.hpp"
30 #include "memory/resourceArea.hpp"
31 #include "memory/sharedHeap.hpp"
32 #include "utilities/copy.hpp"
33
34 /* Copyright (c) 1992-2009 Oracle and/or its affiliates, and Stanford University.
35 See the LICENSE file for license information. */
36
ageTable(bool global)37 ageTable::ageTable(bool global) {
38
39 clear();
40
41 if (UsePerfData && global) {
42
43 ResourceMark rm;
44 EXCEPTION_MARK;
45
46 const char* agetable_ns = "generation.0.agetable";
47 const char* bytes_ns = PerfDataManager::name_space(agetable_ns, "bytes");
48
49 for(int age = 0; age < table_size; age ++) {
50 char age_name[10];
51 jio_snprintf(age_name, sizeof(age_name), "%2.2d", age);
52 const char* cname = PerfDataManager::counter_name(bytes_ns, age_name);
53 _perf_sizes[age] = PerfDataManager::create_variable(SUN_GC, cname,
54 PerfData::U_Bytes,
55 CHECK);
56 }
57
58 const char* cname = PerfDataManager::counter_name(agetable_ns, "size");
59 PerfDataManager::create_constant(SUN_GC, cname, PerfData::U_None,
60 table_size, CHECK);
61 }
62 }
63
clear()64 void ageTable::clear() {
65 for (size_t* p = sizes; p < sizes + table_size; ++p) {
66 *p = 0;
67 }
68 }
69
merge(ageTable * subTable)70 void ageTable::merge(ageTable* subTable) {
71 for (int i = 0; i < table_size; i++) {
72 sizes[i]+= subTable->sizes[i];
73 }
74 }
75
merge_par(ageTable * subTable)76 void ageTable::merge_par(ageTable* subTable) {
77 for (int i = 0; i < table_size; i++) {
78 Atomic::add_ptr(subTable->sizes[i], &sizes[i]);
79 }
80 }
81
compute_tenuring_threshold(size_t survivor_capacity,GCTracer & tracer)82 uint ageTable::compute_tenuring_threshold(size_t survivor_capacity, GCTracer &tracer) {
83 size_t desired_survivor_size = (size_t)((((double) survivor_capacity)*TargetSurvivorRatio)/100);
84 size_t total = 0;
85 uint age = 1;
86 assert(sizes[0] == 0, "no objects with age zero should be recorded");
87 while (age < table_size) {
88 total += sizes[age];
89 // check if including objects of age 'age' made us pass the desired
90 // size, if so 'age' is the new threshold
91 if (total > desired_survivor_size) break;
92 age++;
93 }
94 uint result = age < MaxTenuringThreshold ? age : MaxTenuringThreshold;
95
96 if (PrintTenuringDistribution || UsePerfData || AgeTableTracer::is_tenuring_distribution_event_enabled()) {
97
98 if (PrintTenuringDistribution) {
99 gclog_or_tty->cr();
100 gclog_or_tty->print_cr("Desired survivor size " SIZE_FORMAT " bytes, new threshold %u (max %u)",
101 desired_survivor_size*oopSize, result, (int) MaxTenuringThreshold);
102 }
103
104 total = 0;
105 age = 1;
106 while (age < table_size) {
107 total += sizes[age];
108 if (sizes[age] > 0) {
109 if (PrintTenuringDistribution) {
110 gclog_or_tty->print_cr("- age %3u: " SIZE_FORMAT_W(10) " bytes, " SIZE_FORMAT_W(10) " total",
111 age, sizes[age]*oopSize, total*oopSize);
112 }
113 }
114 AgeTableTracer::send_tenuring_distribution_event(age, wordSize * oopSize, tracer);
115 if (UsePerfData) {
116 _perf_sizes[age]->set_value(sizes[age]*oopSize);
117 }
118 age++;
119 }
120 if (UsePerfData) {
121 SharedHeap* sh = SharedHeap::heap();
122 CollectorPolicy* policy = sh->collector_policy();
123 GCPolicyCounters* gc_counters = policy->counters();
124 gc_counters->tenuring_threshold()->set_value(result);
125 gc_counters->desired_survivor_size()->set_value(
126 desired_survivor_size*oopSize);
127 }
128 }
129
130 return result;
131 }
132