Tue, 19 May 2015 15:49:27 +0200
8061715: gc/g1/TestShrinkAuxiliaryData15.java fails with java.lang.RuntimeException: heap decommit failed - after > before
Summary: added WhiteBox methods to count regions and exact aux data sizes
Reviewed-by: jwilhelm, brutisso
1 /*
2 * Copyright (c) 2011, 2013, 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.
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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
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23 */
25 #include "precompiled.hpp"
26 #include "gc_implementation/g1/g1MonitoringSupport.hpp"
27 #include "gc_implementation/g1/g1CollectedHeap.inline.hpp"
28 #include "gc_implementation/g1/g1CollectorPolicy.hpp"
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) { }
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 }
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 }
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 }
69 void G1OldGenerationCounters::update_all() {
70 size_t committed =
71 G1MonitoringSupport::pad_capacity(_g1mm->old_gen_committed());
72 _current_size->set_value(committed);
73 }
75 G1MonitoringSupport::G1MonitoringSupport(G1CollectedHeap* g1h) :
76 _g1h(g1h),
77 _incremental_collection_counters(NULL),
78 _full_collection_counters(NULL),
79 _old_collection_counters(NULL),
80 _old_space_counters(NULL),
81 _young_collection_counters(NULL),
82 _eden_counters(NULL),
83 _from_counters(NULL),
84 _to_counters(NULL),
86 _overall_reserved(0),
87 _overall_committed(0), _overall_used(0),
88 _young_region_num(0),
89 _young_gen_committed(0),
90 _eden_committed(0), _eden_used(0),
91 _survivor_committed(0), _survivor_used(0),
92 _old_committed(0), _old_used(0) {
94 _overall_reserved = g1h->max_capacity();
95 recalculate_sizes();
97 // Counters for GC collections
98 //
99 // name "collector.0". In a generational collector this would be the
100 // young generation collection.
101 _incremental_collection_counters =
102 new CollectorCounters("G1 incremental collections", 0);
103 // name "collector.1". In a generational collector this would be the
104 // old generation collection.
105 _full_collection_counters =
106 new CollectorCounters("G1 stop-the-world full collections", 1);
108 // timer sampling for all counters supporting sampling only update the
109 // used value. See the take_sample() method. G1 requires both used and
110 // capacity updated so sampling is not currently used. It might
111 // be sufficient to update all counters in take_sample() even though
112 // take_sample() only returns "used". When sampling was used, there
113 // were some anomolous values emitted which may have been the consequence
114 // of not updating all values simultaneously (i.e., see the calculation done
115 // in eden_space_used(), is it possbile that the values used to
116 // calculate either eden_used or survivor_used are being updated by
117 // the collector when the sample is being done?).
118 const bool sampled = false;
120 // "Generation" and "Space" counters.
121 //
122 // name "generation.1" This is logically the old generation in
123 // generational GC terms. The "1, 1" parameters are for
124 // the n-th generation (=1) with 1 space.
125 // Counters are created from minCapacity, maxCapacity, and capacity
126 _old_collection_counters = new G1OldGenerationCounters(this, "old");
128 // name "generation.1.space.0"
129 // Counters are created from maxCapacity, capacity, initCapacity,
130 // and used.
131 _old_space_counters = new HSpaceCounters("space", 0 /* ordinal */,
132 pad_capacity(overall_reserved()) /* max_capacity */,
133 pad_capacity(old_space_committed()) /* init_capacity */,
134 _old_collection_counters);
136 // Young collection set
137 // name "generation.0". This is logically the young generation.
138 // The "0, 3" are paremeters for the n-th genertaion (=0) with 3 spaces.
139 // See _old_collection_counters for additional counters
140 _young_collection_counters = new G1YoungGenerationCounters(this, "young");
142 // name "generation.0.space.0"
143 // See _old_space_counters for additional counters
144 _eden_counters = new HSpaceCounters("eden", 0 /* ordinal */,
145 pad_capacity(overall_reserved()) /* max_capacity */,
146 pad_capacity(eden_space_committed()) /* init_capacity */,
147 _young_collection_counters);
149 // name "generation.0.space.1"
150 // See _old_space_counters for additional counters
151 // Set the arguments to indicate that this survivor space is not used.
152 _from_counters = new HSpaceCounters("s0", 1 /* ordinal */,
153 pad_capacity(0) /* max_capacity */,
154 pad_capacity(0) /* init_capacity */,
155 _young_collection_counters);
157 // name "generation.0.space.2"
158 // See _old_space_counters for additional counters
159 _to_counters = new HSpaceCounters("s1", 2 /* ordinal */,
160 pad_capacity(overall_reserved()) /* max_capacity */,
161 pad_capacity(survivor_space_committed()) /* init_capacity */,
162 _young_collection_counters);
164 if (UsePerfData) {
165 // Given that this survivor space is not used, we update it here
166 // once to reflect that its used space is 0 so that we don't have to
167 // worry about updating it again later.
168 _from_counters->update_used(0);
169 }
170 }
172 void G1MonitoringSupport::recalculate_sizes() {
173 G1CollectedHeap* g1 = g1h();
175 // Recalculate all the sizes from scratch. We assume that this is
176 // called at a point where no concurrent updates to the various
177 // values we read here are possible (i.e., at a STW phase at the end
178 // of a GC).
180 uint young_list_length = g1->young_list()->length();
181 uint survivor_list_length = g1->g1_policy()->recorded_survivor_regions();
182 assert(young_list_length >= survivor_list_length, "invariant");
183 uint eden_list_length = young_list_length - survivor_list_length;
184 // Max length includes any potential extensions to the young gen
185 // we'll do when the GC locker is active.
186 uint young_list_max_length = g1->g1_policy()->young_list_max_length();
187 assert(young_list_max_length >= survivor_list_length, "invariant");
188 uint eden_list_max_length = young_list_max_length - survivor_list_length;
190 _overall_used = g1->used_unlocked();
191 _eden_used = (size_t) eden_list_length * HeapRegion::GrainBytes;
192 _survivor_used = (size_t) survivor_list_length * HeapRegion::GrainBytes;
193 _young_region_num = young_list_length;
194 _old_used = subtract_up_to_zero(_overall_used, _eden_used + _survivor_used);
196 // First calculate the committed sizes that can be calculated independently.
197 _survivor_committed = _survivor_used;
198 _old_committed = HeapRegion::align_up_to_region_byte_size(_old_used);
200 // Next, start with the overall committed size.
201 _overall_committed = g1->capacity();
202 size_t committed = _overall_committed;
204 // Remove the committed size we have calculated so far (for the
205 // survivor and old space).
206 assert(committed >= (_survivor_committed + _old_committed), "sanity");
207 committed -= _survivor_committed + _old_committed;
209 // Next, calculate and remove the committed size for the eden.
210 _eden_committed = (size_t) eden_list_max_length * HeapRegion::GrainBytes;
211 // Somewhat defensive: be robust in case there are inaccuracies in
212 // the calculations
213 _eden_committed = MIN2(_eden_committed, committed);
214 committed -= _eden_committed;
216 // Finally, give the rest to the old space...
217 _old_committed += committed;
218 // ..and calculate the young gen committed.
219 _young_gen_committed = _eden_committed + _survivor_committed;
221 assert(_overall_committed ==
222 (_eden_committed + _survivor_committed + _old_committed),
223 "the committed sizes should add up");
224 // Somewhat defensive: cap the eden used size to make sure it
225 // never exceeds the committed size.
226 _eden_used = MIN2(_eden_used, _eden_committed);
227 // _survivor_committed and _old_committed are calculated in terms of
228 // the corresponding _*_used value, so the next two conditions
229 // should hold.
230 assert(_survivor_used <= _survivor_committed, "post-condition");
231 assert(_old_used <= _old_committed, "post-condition");
232 }
234 void G1MonitoringSupport::recalculate_eden_size() {
235 G1CollectedHeap* g1 = g1h();
237 // When a new eden region is allocated, only the eden_used size is
238 // affected (since we have recalculated everything else at the last GC).
240 uint young_region_num = g1h()->young_list()->length();
241 if (young_region_num > _young_region_num) {
242 uint diff = young_region_num - _young_region_num;
243 _eden_used += (size_t) diff * HeapRegion::GrainBytes;
244 // Somewhat defensive: cap the eden used size to make sure it
245 // never exceeds the committed size.
246 _eden_used = MIN2(_eden_used, _eden_committed);
247 _young_region_num = young_region_num;
248 }
249 }
251 void G1MonitoringSupport::update_sizes() {
252 recalculate_sizes();
253 if (UsePerfData) {
254 eden_counters()->update_capacity(pad_capacity(eden_space_committed()));
255 eden_counters()->update_used(eden_space_used());
256 // only the to survivor space (s1) is active, so we don't need to
257 // update the counteres for the from survivor space (s0)
258 to_counters()->update_capacity(pad_capacity(survivor_space_committed()));
259 to_counters()->update_used(survivor_space_used());
260 old_space_counters()->update_capacity(pad_capacity(old_space_committed()));
261 old_space_counters()->update_used(old_space_used());
262 old_collection_counters()->update_all();
263 young_collection_counters()->update_all();
264 MetaspaceCounters::update_performance_counters();
265 CompressedClassSpaceCounters::update_performance_counters();
266 }
267 }
269 void G1MonitoringSupport::update_eden_size() {
270 recalculate_eden_size();
271 if (UsePerfData) {
272 eden_counters()->update_used(eden_space_used());
273 }
274 }