1 /*
2 * Copyright (c) 2011, 2015, 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/g1CollectorPolicy.hpp"
28 #include "gc/g1/g1MonitoringSupport.hpp"
29
30 G1GenerationCounters::G1GenerationCounters(G1MonitoringSupport* g1mm,
31 const char* name,
32 int ordinal, int spaces,
33 size_t min_capacity,
34 size_t max_capacity,
35 size_t curr_capacity)
36 : GenerationCounters(name, ordinal, spaces, min_capacity,
37 max_capacity, curr_capacity), _g1mm(g1mm) { }
38
39 // We pad the capacity three times given that the young generation
40 // contains three spaces (eden and two survivors).
41 G1YoungGenerationCounters::G1YoungGenerationCounters(G1MonitoringSupport* g1mm,
42 const char* name)
43 : G1GenerationCounters(g1mm, name, 0 /* ordinal */, 3 /* spaces */,
44 G1MonitoringSupport::pad_capacity(0, 3) /* min_capacity */,
45 G1MonitoringSupport::pad_capacity(g1mm->young_gen_max(), 3),
46 G1MonitoringSupport::pad_capacity(0, 3) /* curr_capacity */) {
47 if (UsePerfData) {
48 update_all();
49 }
50 }
51
52 G1OldGenerationCounters::G1OldGenerationCounters(G1MonitoringSupport* g1mm,
53 const char* name)
54 : G1GenerationCounters(g1mm, name, 1 /* ordinal */, 1 /* spaces */,
55 G1MonitoringSupport::pad_capacity(0) /* min_capacity */,
56 G1MonitoringSupport::pad_capacity(g1mm->old_gen_max()),
57 G1MonitoringSupport::pad_capacity(0) /* curr_capacity */) {
58 if (UsePerfData) {
59 update_all();
60 }
61 }
62
63 void G1YoungGenerationCounters::update_all() {
64 size_t committed =
65 G1MonitoringSupport::pad_capacity(_g1mm->young_gen_committed(), 3);
66 _current_size->set_value(committed);
67 }
68
69 void G1OldGenerationCounters::update_all() {
70 size_t committed =
71 G1MonitoringSupport::pad_capacity(_g1mm->old_gen_committed());
72 _current_size->set_value(committed);
73 }
74
75 G1MonitoringSupport::G1MonitoringSupport(G1CollectedHeap* g1h) :
76 _g1h(g1h),
77 _incremental_collection_counters(NULL),
78 _full_collection_counters(NULL),
79 _conc_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 // name "collector.2". In a generational collector this would be the
109 // STW phases in concurrent collection.
110 _conc_collection_counters =
111 new CollectorCounters("G1 stop-the-world phases", 2);
112
113 // timer sampling for all counters supporting sampling only update the
114 // used value. See the take_sample() method. G1 requires both used and
115 // capacity updated so sampling is not currently used. It might
116 // be sufficient to update all counters in take_sample() even though
117 // take_sample() only returns "used". When sampling was used, there
118 // were some anomolous values emitted which may have been the consequence
119 // of not updating all values simultaneously (i.e., see the calculation done
120 // in eden_space_used(), is it possible that the values used to
121 // calculate either eden_used or survivor_used are being updated by
122 // the collector when the sample is being done?).
123 const bool sampled = false;
124
125 // "Generation" and "Space" counters.
126 //
127 // name "generation.1" This is logically the old generation in
128 // generational GC terms. The "1, 1" parameters are for
129 // the n-th generation (=1) with 1 space.
130 // Counters are created from minCapacity, maxCapacity, and capacity
131 _old_collection_counters = new G1OldGenerationCounters(this, "old");
132
133 // name "generation.1.space.0"
134 // Counters are created from maxCapacity, capacity, initCapacity,
135 // and used.
136 _old_space_counters = new HSpaceCounters("space", 0 /* ordinal */,
137 pad_capacity(overall_reserved()) /* max_capacity */,
138 pad_capacity(old_space_committed()) /* init_capacity */,
139 _old_collection_counters);
140
141 // Young collection set
142 // name "generation.0". This is logically the young generation.
143 // The "0, 3" are parameters for the n-th generation (=0) with 3 spaces.
144 // See _old_collection_counters for additional counters
145 _young_collection_counters = new G1YoungGenerationCounters(this, "young");
146
147 // name "generation.0.space.0"
148 // See _old_space_counters for additional counters
149 _eden_counters = new HSpaceCounters("eden", 0 /* ordinal */,
150 pad_capacity(overall_reserved()) /* max_capacity */,
151 pad_capacity(eden_space_committed()) /* init_capacity */,
152 _young_collection_counters);
153
154 // name "generation.0.space.1"
155 // See _old_space_counters for additional counters
156 // Set the arguments to indicate that this survivor space is not used.
157 _from_counters = new HSpaceCounters("s0", 1 /* ordinal */,
158 pad_capacity(0) /* max_capacity */,
159 pad_capacity(0) /* init_capacity */,
160 _young_collection_counters);
161
162 // name "generation.0.space.2"
163 // See _old_space_counters for additional counters
164 _to_counters = new HSpaceCounters("s1", 2 /* ordinal */,
165 pad_capacity(overall_reserved()) /* max_capacity */,
166 pad_capacity(survivor_space_committed()) /* init_capacity */,
167 _young_collection_counters);
168
169 if (UsePerfData) {
170 // Given that this survivor space is not used, we update it here
171 // once to reflect that its used space is 0 so that we don't have to
172 // worry about updating it again later.
173 _from_counters->update_used(0);
174 }
175 }
176
177 void G1MonitoringSupport::recalculate_sizes() {
178 G1CollectedHeap* g1 = g1h();
179
180 // Recalculate all the sizes from scratch. We assume that this is
181 // called at a point where no concurrent updates to the various
182 // values we read here are possible (i.e., at a STW phase at the end
183 // of a GC).
184
185 uint young_list_length = g1->young_list()->length();
186 uint survivor_list_length = g1->g1_policy()->recorded_survivor_regions();
187 assert(young_list_length >= survivor_list_length, "invariant");
188 uint eden_list_length = young_list_length - survivor_list_length;
189 // Max length includes any potential extensions to the young gen
190 // we'll do when the GC locker is active.
191 uint young_list_max_length = g1->g1_policy()->young_list_max_length();
192 assert(young_list_max_length >= survivor_list_length, "invariant");
193 uint eden_list_max_length = young_list_max_length - survivor_list_length;
194
195 _overall_used = g1->used_unlocked();
196 _eden_used = (size_t) eden_list_length * HeapRegion::GrainBytes;
197 _survivor_used = (size_t) survivor_list_length * HeapRegion::GrainBytes;
198 _young_region_num = young_list_length;
199 _old_used = subtract_up_to_zero(_overall_used, _eden_used + _survivor_used);
200
201 // First calculate the committed sizes that can be calculated independently.
202 _survivor_committed = _survivor_used;
203 _old_committed = HeapRegion::align_up_to_region_byte_size(_old_used);
204
205 // Next, start with the overall committed size.
206 _overall_committed = g1->capacity();
207 size_t committed = _overall_committed;
208
209 // Remove the committed size we have calculated so far (for the
210 // survivor and old space).
211 assert(committed >= (_survivor_committed + _old_committed), "sanity");
212 committed -= _survivor_committed + _old_committed;
213
214 // Next, calculate and remove the committed size for the eden.
215 _eden_committed = (size_t) eden_list_max_length * HeapRegion::GrainBytes;
216 // Somewhat defensive: be robust in case there are inaccuracies in
217 // the calculations
218 _eden_committed = MIN2(_eden_committed, committed);
219 committed -= _eden_committed;
220
221 // Finally, give the rest to the old space...
222 _old_committed += committed;
223 // ..and calculate the young gen committed.
224 _young_gen_committed = _eden_committed + _survivor_committed;
225
226 assert(_overall_committed ==
227 (_eden_committed + _survivor_committed + _old_committed),
228 "the committed sizes should add up");
229 // Somewhat defensive: cap the eden used size to make sure it
230 // never exceeds the committed size.
231 _eden_used = MIN2(_eden_used, _eden_committed);
232 // _survivor_committed and _old_committed are calculated in terms of
233 // the corresponding _*_used value, so the next two conditions
234 // should hold.
235 assert(_survivor_used <= _survivor_committed, "post-condition");
236 assert(_old_used <= _old_committed, "post-condition");
237 }
238
239 void G1MonitoringSupport::recalculate_eden_size() {
240 G1CollectedHeap* g1 = g1h();
241
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_list()->length();
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 }