1 /*
2 * Copyright (c) 2011, 2016, 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
31 G1GenerationCounters::G1GenerationCounters(G1MonitoringSupport* g1mm,
32 const char* name,
33 int ordinal, int spaces,
34 size_t min_capacity,
35 size_t max_capacity,
36 size_t curr_capacity)
37 : GenerationCounters(name, ordinal, spaces, min_capacity,
38 max_capacity, curr_capacity), _g1mm(g1mm) { }
39
40 // We pad the capacity three times given that the young generation
41 // contains three spaces (eden and two survivors).
42 G1YoungGenerationCounters::G1YoungGenerationCounters(G1MonitoringSupport* g1mm,
43 const char* name)
44 : G1GenerationCounters(g1mm, name, 0 /* ordinal */, 3 /* spaces */,
45 G1MonitoringSupport::pad_capacity(0, 3) /* min_capacity */,
46 G1MonitoringSupport::pad_capacity(g1mm->young_gen_max(), 3),
47 G1MonitoringSupport::pad_capacity(0, 3) /* curr_capacity */) {
48 if (UsePerfData) {
49 update_all();
50 }
51 }
52
53 G1OldGenerationCounters::G1OldGenerationCounters(G1MonitoringSupport* g1mm,
54 const char* name)
55 : G1GenerationCounters(g1mm, name, 1 /* ordinal */, 1 /* spaces */,
56 G1MonitoringSupport::pad_capacity(0) /* min_capacity */,
57 G1MonitoringSupport::pad_capacity(g1mm->old_gen_max()),
58 G1MonitoringSupport::pad_capacity(0) /* curr_capacity */) {
59 if (UsePerfData) {
60 update_all();
61 }
62 }
63
64 void G1YoungGenerationCounters::update_all() {
65 size_t committed =
66 G1MonitoringSupport::pad_capacity(_g1mm->young_gen_committed(), 3);
67 _current_size->set_value(committed);
68 }
69
70 void G1OldGenerationCounters::update_all() {
71 size_t committed =
72 G1MonitoringSupport::pad_capacity(_g1mm->old_gen_committed());
73 _current_size->set_value(committed);
74 }
75
76 G1MonitoringSupport::G1MonitoringSupport(G1CollectedHeap* g1h) :
77 _g1h(g1h),
78 _incremental_collection_counters(NULL),
79 _full_collection_counters(NULL),
80 _old_collection_counters(NULL),
81 _old_space_counters(NULL),
82 _young_collection_counters(NULL),
83 _eden_counters(NULL),
84 _from_counters(NULL),
85 _to_counters(NULL),
86
87 _overall_reserved(0),
88 _overall_committed(0), _overall_used(0),
89 _young_region_num(0),
90 _young_gen_committed(0),
91 _eden_committed(0), _eden_used(0),
92 _survivor_committed(0), _survivor_used(0),
93 _old_committed(0), _old_used(0) {
94
95 _overall_reserved = g1h->max_capacity();
96 recalculate_sizes();
97
98 // Counters for GC collections
99 //
100 // name "collector.0". In a generational collector this would be the
101 // young generation collection.
102 _incremental_collection_counters =
103 new CollectorCounters("G1 incremental collections", 0);
104 // name "collector.1". In a generational collector this would be the
105 // old generation collection.
106 _full_collection_counters =
107 new CollectorCounters("G1 stop-the-world full collections", 1);
108
109 // timer sampling for all counters supporting sampling only update the
110 // used value. See the take_sample() method. G1 requires both used and
111 // capacity updated so sampling is not currently used. It might
112 // be sufficient to update all counters in take_sample() even though
113 // take_sample() only returns "used". When sampling was used, there
114 // were some anomolous values emitted which may have been the consequence
115 // of not updating all values simultaneously (i.e., see the calculation done
116 // in eden_space_used(), is it possible that the values used to
117 // calculate either eden_used or survivor_used are being updated by
118 // the collector when the sample is being done?).
119 const bool sampled = false;
120
121 // "Generation" and "Space" counters.
122 //
123 // name "generation.1" This is logically the old generation in
124 // generational GC terms. The "1, 1" parameters are for
125 // the n-th generation (=1) with 1 space.
126 // Counters are created from minCapacity, maxCapacity, and capacity
127 _old_collection_counters = new G1OldGenerationCounters(this, "old");
128
129 // name "generation.1.space.0"
130 // Counters are created from maxCapacity, capacity, initCapacity,
131 // and used.
132 _old_space_counters = new HSpaceCounters(_old_collection_counters->name_space(),
133 "space", 0 /* ordinal */,
134 pad_capacity(overall_reserved()) /* max_capacity */,
135 pad_capacity(old_space_committed()) /* init_capacity */);
136
137 // Young collection set
138 // name "generation.0". This is logically the young generation.
139 // The "0, 3" are parameters for the n-th generation (=0) with 3 spaces.
140 // See _old_collection_counters for additional counters
141 _young_collection_counters = new G1YoungGenerationCounters(this, "young");
142
143 const char* young_collection_name_space = _young_collection_counters->name_space();
144
145 // name "generation.0.space.0"
146 // See _old_space_counters for additional counters
147 _eden_counters = new HSpaceCounters(young_collection_name_space,
148 "eden", 0 /* ordinal */,
149 pad_capacity(overall_reserved()) /* max_capacity */,
150 pad_capacity(eden_space_committed()) /* init_capacity */);
151
152 // name "generation.0.space.1"
153 // See _old_space_counters for additional counters
154 // Set the arguments to indicate that this survivor space is not used.
155 _from_counters = new HSpaceCounters(young_collection_name_space,
156 "s0", 1 /* ordinal */,
157 pad_capacity(0) /* max_capacity */,
158 pad_capacity(0) /* init_capacity */);
159
160 // name "generation.0.space.2"
161 // See _old_space_counters for additional counters
162 _to_counters = new HSpaceCounters(young_collection_name_space,
163 "s1", 2 /* ordinal */,
164 pad_capacity(overall_reserved()) /* max_capacity */,
165 pad_capacity(survivor_space_committed()) /* init_capacity */);
166
167 if (UsePerfData) {
168 // Given that this survivor space is not used, we update it here
169 // once to reflect that its used space is 0 so that we don't have to
170 // worry about updating it again later.
171 _from_counters->update_used(0);
172 }
173 }
174
175 void G1MonitoringSupport::recalculate_sizes() {
176 G1CollectedHeap* g1 = g1h();
177
178 // Recalculate all the sizes from scratch. We assume that this is
179 // called at a point where no concurrent updates to the various
180 // values we read here are possible (i.e., at a STW phase at the end
181 // of a GC).
182
183 uint young_list_length = g1->young_regions_count();
184 uint survivor_list_length = g1->survivor_regions_count();
185 assert(young_list_length >= survivor_list_length, "invariant");
186 uint eden_list_length = young_list_length - survivor_list_length;
187 // Max length includes any potential extensions to the young gen
188 // we'll do when the GC locker is active.
189 uint young_list_max_length = g1->g1_policy()->young_list_max_length();
190 assert(young_list_max_length >= survivor_list_length, "invariant");
191 uint eden_list_max_length = young_list_max_length - survivor_list_length;
192
193 _overall_used = g1->used_unlocked();
194 _eden_used = (size_t) eden_list_length * HeapRegion::GrainBytes;
195 _survivor_used = (size_t) survivor_list_length * HeapRegion::GrainBytes;
196 _young_region_num = young_list_length;
197 _old_used = subtract_up_to_zero(_overall_used, _eden_used + _survivor_used);
198
199 // First calculate the committed sizes that can be calculated independently.
200 _survivor_committed = _survivor_used;
201 _old_committed = HeapRegion::align_up_to_region_byte_size(_old_used);
202
203 // Next, start with the overall committed size.
204 _overall_committed = g1->capacity();
205 size_t committed = _overall_committed;
206
207 // Remove the committed size we have calculated so far (for the
208 // survivor and old space).
209 assert(committed >= (_survivor_committed + _old_committed), "sanity");
210 committed -= _survivor_committed + _old_committed;
211
212 // Next, calculate and remove the committed size for the eden.
213 _eden_committed = (size_t) eden_list_max_length * HeapRegion::GrainBytes;
214 // Somewhat defensive: be robust in case there are inaccuracies in
215 // the calculations
216 _eden_committed = MIN2(_eden_committed, committed);
217 committed -= _eden_committed;
218
219 // Finally, give the rest to the old space...
220 _old_committed += committed;
221 // ..and calculate the young gen committed.
222 _young_gen_committed = _eden_committed + _survivor_committed;
223
224 assert(_overall_committed ==
225 (_eden_committed + _survivor_committed + _old_committed),
226 "the committed sizes should add up");
227 // Somewhat defensive: cap the eden used size to make sure it
228 // never exceeds the committed size.
229 _eden_used = MIN2(_eden_used, _eden_committed);
230 // _survivor_committed and _old_committed are calculated in terms of
231 // the corresponding _*_used value, so the next two conditions
232 // should hold.
233 assert(_survivor_used <= _survivor_committed, "post-condition");
234 assert(_old_used <= _old_committed, "post-condition");
235 }
236
237 void G1MonitoringSupport::recalculate_eden_size() {
238 G1CollectedHeap* g1 = g1h();
239
240 // When a new eden region is allocated, only the eden_used size is
241 // affected (since we have recalculated everything else at the last GC).
242
243 uint young_region_num = g1h()->young_regions_count();
244 if (young_region_num > _young_region_num) {
245 uint diff = young_region_num - _young_region_num;
246 _eden_used += (size_t) diff * HeapRegion::GrainBytes;
247 // Somewhat defensive: cap the eden used size to make sure it
248 // never exceeds the committed size.
249 _eden_used = MIN2(_eden_used, _eden_committed);
250 _young_region_num = young_region_num;
251 }
252 }
253
254 void G1MonitoringSupport::update_sizes() {
255 recalculate_sizes();
256 if (UsePerfData) {
257 eden_counters()->update_capacity(pad_capacity(eden_space_committed()));
258 eden_counters()->update_used(eden_space_used());
259 // only the to survivor space (s1) is active, so we don't need to
260 // update the counters for the from survivor space (s0)
261 to_counters()->update_capacity(pad_capacity(survivor_space_committed()));
262 to_counters()->update_used(survivor_space_used());
263 old_space_counters()->update_capacity(pad_capacity(old_space_committed()));
264 old_space_counters()->update_used(old_space_used());
265 old_collection_counters()->update_all();
266 young_collection_counters()->update_all();
267 MetaspaceCounters::update_performance_counters();
268 CompressedClassSpaceCounters::update_performance_counters();
269 }
270 }
271
272 void G1MonitoringSupport::update_eden_size() {
273 recalculate_eden_size();
274 if (UsePerfData) {
275 eden_counters()->update_used(eden_space_used());
276 }
277 }