1 /*
2 * Copyright (c) 2011, 2018, 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/g1MonitoringSupport.hpp"
28 #include "gc/g1/g1Policy.hpp"
29 #include "gc/shared/collectorCounters.hpp"
30 #include "gc/shared/hSpaceCounters.hpp"
31 #include "memory/metaspaceCounters.hpp"
32
33 G1GenerationCounters::G1GenerationCounters(G1MonitoringSupport* g1mm,
34 const char* name,
35 int ordinal, int spaces,
36 size_t min_capacity,
37 size_t max_capacity,
38 size_t curr_capacity)
39 : GenerationCounters(name, ordinal, spaces, min_capacity,
40 max_capacity, curr_capacity), _g1mm(g1mm) { }
41
42 // We pad the capacity three times given that the young generation
43 // contains three spaces (eden and two survivors).
44 G1YoungGenerationCounters::G1YoungGenerationCounters(G1MonitoringSupport* g1mm,
45 const char* name)
46 : G1GenerationCounters(g1mm, name, 0 /* ordinal */, 3 /* spaces */,
47 G1MonitoringSupport::pad_capacity(0, 3) /* min_capacity */,
48 G1MonitoringSupport::pad_capacity(g1mm->young_gen_max(), 3),
49 G1MonitoringSupport::pad_capacity(0, 3) /* curr_capacity */) {
50 if (UsePerfData) {
51 update_all();
52 }
53 }
54
55 G1OldGenerationCounters::G1OldGenerationCounters(G1MonitoringSupport* g1mm,
56 const char* name)
57 : G1GenerationCounters(g1mm, name, 1 /* ordinal */, 1 /* spaces */,
58 G1MonitoringSupport::pad_capacity(0) /* min_capacity */,
59 G1MonitoringSupport::pad_capacity(g1mm->old_gen_max()),
60 G1MonitoringSupport::pad_capacity(0) /* curr_capacity */) {
61 if (UsePerfData) {
62 update_all();
63 }
64 }
65
66 void G1YoungGenerationCounters::update_all() {
67 size_t committed =
68 G1MonitoringSupport::pad_capacity(_g1mm->young_gen_committed(), 3);
69 _current_size->set_value(committed);
70 }
71
72 void G1OldGenerationCounters::update_all() {
73 size_t committed =
74 G1MonitoringSupport::pad_capacity(_g1mm->old_gen_committed());
75 _current_size->set_value(committed);
76 }
77
78 G1MonitoringSupport::G1MonitoringSupport(G1CollectedHeap* g1h) :
79 _g1h(g1h),
80 _incremental_collection_counters(NULL),
81 _full_collection_counters(NULL),
82 _conc_collection_counters(NULL),
83 _old_collection_counters(NULL),
84 _old_space_counters(NULL),
85 _young_collection_counters(NULL),
86 _eden_counters(NULL),
87 _from_counters(NULL),
88 _to_counters(NULL),
89
90 _overall_reserved(0),
91 _overall_committed(0), _overall_used(0),
92 _young_region_num(0),
93 _young_gen_committed(0),
94 _eden_committed(0), _eden_used(0),
95 _survivor_committed(0), _survivor_used(0),
96 _old_committed(0), _old_used(0) {
97
98 _overall_reserved = g1h->max_capacity();
99 recalculate_sizes();
100
101 // Counters for GC collections
102 //
103 // name "collector.0". In a generational collector this would be the
104 // young generation collection.
105 _incremental_collection_counters =
106 new CollectorCounters("G1 incremental collections", 0);
107 // name "collector.1". In a generational collector this would be the
108 // old generation collection.
109 _full_collection_counters =
110 new CollectorCounters("G1 stop-the-world full collections", 1);
111 // name "collector.2". In a generational collector this would be the
112 // STW phases in concurrent collection.
113 _conc_collection_counters =
114 new CollectorCounters("G1 stop-the-world phases", 2);
115
116 // timer sampling for all counters supporting sampling only update the
117 // used value. See the take_sample() method. G1 requires both used and
118 // capacity updated so sampling is not currently used. It might
119 // be sufficient to update all counters in take_sample() even though
120 // take_sample() only returns "used". When sampling was used, there
121 // were some anomolous values emitted which may have been the consequence
122 // of not updating all values simultaneously (i.e., see the calculation done
123 // in eden_space_used(), is it possible that the values used to
124 // calculate either eden_used or survivor_used are being updated by
125 // the collector when the sample is being done?).
126 const bool sampled = false;
127
128 // "Generation" and "Space" counters.
129 //
130 // name "generation.1" This is logically the old generation in
131 // generational GC terms. The "1, 1" parameters are for
132 // the n-th generation (=1) with 1 space.
133 // Counters are created from minCapacity, maxCapacity, and capacity
134 _old_collection_counters = new G1OldGenerationCounters(this, "old");
135
136 // name "generation.1.space.0"
137 // Counters are created from maxCapacity, capacity, initCapacity,
138 // and used.
139 _old_space_counters = new HSpaceCounters(_old_collection_counters->name_space(),
140 "space", 0 /* ordinal */,
141 pad_capacity(overall_reserved()) /* max_capacity */,
142 pad_capacity(old_space_committed()) /* init_capacity */);
143
144 // Young collection set
145 // name "generation.0". This is logically the young generation.
146 // The "0, 3" are parameters for the n-th generation (=0) with 3 spaces.
147 // See _old_collection_counters for additional counters
148 _young_collection_counters = new G1YoungGenerationCounters(this, "young");
149
150 const char* young_collection_name_space = _young_collection_counters->name_space();
151
152 // name "generation.0.space.0"
153 // See _old_space_counters for additional counters
154 _eden_counters = new HSpaceCounters(young_collection_name_space,
155 "eden", 0 /* ordinal */,
156 pad_capacity(overall_reserved()) /* max_capacity */,
157 pad_capacity(eden_space_committed()) /* init_capacity */);
158
159 // name "generation.0.space.1"
160 // See _old_space_counters for additional counters
161 // Set the arguments to indicate that this survivor space is not used.
162 _from_counters = new HSpaceCounters(young_collection_name_space,
163 "s0", 1 /* ordinal */,
164 pad_capacity(0) /* max_capacity */,
165 pad_capacity(0) /* init_capacity */);
166
167 // name "generation.0.space.2"
168 // See _old_space_counters for additional counters
169 _to_counters = new HSpaceCounters(young_collection_name_space,
170 "s1", 2 /* ordinal */,
171 pad_capacity(overall_reserved()) /* max_capacity */,
172 pad_capacity(survivor_space_committed()) /* init_capacity */);
173
174 if (UsePerfData) {
175 // Given that this survivor space is not used, we update it here
176 // once to reflect that its used space is 0 so that we don't have to
177 // worry about updating it again later.
178 _from_counters->update_used(0);
179 }
180 }
181
182 void G1MonitoringSupport::recalculate_sizes() {
183 // Recalculate all the sizes from scratch. We assume that this is
184 // called at a point where no concurrent updates to the various
185 // values we read here are possible (i.e., at a STW phase at the end
186 // of a GC).
187
188 uint young_list_length = _g1h->young_regions_count();
189 uint survivor_list_length = _g1h->survivor_regions_count();
190 assert(young_list_length >= survivor_list_length, "invariant");
191 uint eden_list_length = young_list_length - survivor_list_length;
192 // Max length includes any potential extensions to the young gen
193 // we'll do when the GC locker is active.
194 uint young_list_max_length = _g1h->g1_policy()->young_list_max_length();
195 assert(young_list_max_length >= survivor_list_length, "invariant");
196 uint eden_list_max_length = young_list_max_length - survivor_list_length;
197
198 _overall_used = _g1h->used_unlocked();
199 _eden_used = (size_t) eden_list_length * HeapRegion::GrainBytes;
200 _survivor_used = (size_t) survivor_list_length * HeapRegion::GrainBytes;
201 _young_region_num = young_list_length;
202 _old_used = subtract_up_to_zero(_overall_used, _eden_used + _survivor_used);
203
204 // First calculate the committed sizes that can be calculated independently.
205 _survivor_committed = _survivor_used;
206 _old_committed = HeapRegion::align_up_to_region_byte_size(_old_used);
207
208 // Next, start with the overall committed size.
209 _overall_committed = _g1h->capacity();
210 size_t committed = _overall_committed;
211
212 // Remove the committed size we have calculated so far (for the
213 // survivor and old space).
214 assert(committed >= (_survivor_committed + _old_committed), "sanity");
215 committed -= _survivor_committed + _old_committed;
216
217 // Next, calculate and remove the committed size for the eden.
218 _eden_committed = (size_t) eden_list_max_length * HeapRegion::GrainBytes;
219 // Somewhat defensive: be robust in case there are inaccuracies in
220 // the calculations
221 _eden_committed = MIN2(_eden_committed, committed);
222 committed -= _eden_committed;
223
224 // Finally, give the rest to the old space...
225 _old_committed += committed;
226 // ..and calculate the young gen committed.
227 _young_gen_committed = _eden_committed + _survivor_committed;
228
229 assert(_overall_committed ==
230 (_eden_committed + _survivor_committed + _old_committed),
231 "the committed sizes should add up");
232 // Somewhat defensive: cap the eden used size to make sure it
233 // never exceeds the committed size.
234 _eden_used = MIN2(_eden_used, _eden_committed);
235 // _survivor_committed and _old_committed are calculated in terms of
236 // the corresponding _*_used value, so the next two conditions
237 // should hold.
238 assert(_survivor_used <= _survivor_committed, "post-condition");
239 assert(_old_used <= _old_committed, "post-condition");
240 }
241
242 void G1MonitoringSupport::recalculate_eden_size() {
243 // When a new eden region is allocated, only the eden_used size is
244 // affected (since we have recalculated everything else at the last GC).
245
246 uint young_region_num = _g1h->young_regions_count();
247 if (young_region_num > _young_region_num) {
248 uint diff = young_region_num - _young_region_num;
249 _eden_used += (size_t) diff * HeapRegion::GrainBytes;
250 // Somewhat defensive: cap the eden used size to make sure it
251 // never exceeds the committed size.
252 _eden_used = MIN2(_eden_used, _eden_committed);
253 _young_region_num = young_region_num;
254 }
255 }
256
257 void G1MonitoringSupport::update_sizes() {
258 recalculate_sizes();
259 if (UsePerfData) {
260 eden_counters()->update_capacity(pad_capacity(eden_space_committed()));
261 eden_counters()->update_used(eden_space_used());
262 // only the to survivor space (s1) is active, so we don't need to
263 // update the counters for the from survivor space (s0)
264 to_counters()->update_capacity(pad_capacity(survivor_space_committed()));
265 to_counters()->update_used(survivor_space_used());
266 old_space_counters()->update_capacity(pad_capacity(old_space_committed()));
267 old_space_counters()->update_used(old_space_used());
268 old_collection_counters()->update_all();
269 young_collection_counters()->update_all();
270 MetaspaceCounters::update_performance_counters();
271 CompressedClassSpaceCounters::update_performance_counters();
272 }
273 }
274
275 void G1MonitoringSupport::update_eden_size() {
276 recalculate_eden_size();
277 if (UsePerfData) {
278 eden_counters()->update_used(eden_space_used());
279 }
280 }