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