1 /*
2 * Copyright (c) 2003, 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/parallel/adjoiningGenerations.hpp"
27 #include "gc/parallel/adjoiningVirtualSpaces.hpp"
28 #include "gc/parallel/generationSizer.hpp"
29 #include "gc/parallel/parallelScavengeHeap.hpp"
30 #include "logging/log.hpp"
31 #include "logging/logStream.hpp"
32 #include "memory/resourceArea.hpp"
33 #include "utilities/align.hpp"
34 #include "utilities/ostream.hpp"
35
36 // If boundary moving is being used, create the young gen and old
37 // gen with ASPSYoungGen and ASPSOldGen, respectively. Revert to
38 // the old behavior otherwise (with PSYoungGen and PSOldGen).
39
40 AdjoiningGenerations::AdjoiningGenerations(ReservedSpace old_young_rs,
41 GenerationSizer* policy,
42 size_t alignment) :
43 _virtual_spaces(old_young_rs, policy->min_old_size(),
44 policy->min_young_size(), alignment) {
45 size_t init_low_byte_size = policy->initial_old_size();
46 size_t min_low_byte_size = policy->min_old_size();
47 size_t max_low_byte_size = policy->max_old_size();
48 size_t init_high_byte_size = policy->initial_young_size();
49 size_t min_high_byte_size = policy->min_young_size();
50 size_t max_high_byte_size = policy->max_young_size();
51
52 assert(min_low_byte_size <= init_low_byte_size &&
53 init_low_byte_size <= max_low_byte_size, "Parameter check");
54 assert(min_high_byte_size <= init_high_byte_size &&
55 init_high_byte_size <= max_high_byte_size, "Parameter check");
56 // Create the generations differently based on the option to
57 // move the boundary.
58 if (UseAdaptiveGCBoundary) {
59 // Initialize the adjoining virtual spaces. Then pass the
60 // a virtual to each generation for initialization of the
61 // generation.
62
63 if (os::has_nvdimm()) {
64 _virtual_spaces.setup_fd(old_young_rs.nvdimm_fd());
65 #if defined(_WINDOWS)
66 log_info(gc, heap)("On Windows, ParallelOldGC with NVDIMM does not support adaptive sizing of OldGen. ");
67 init_low_byte_size = policy->max_old_size();
68 min_low_byte_size = policy->max_old_size();
69 max_low_byte_size = policy->max_old_size();
70 #endif
71 }
72 // Does the actual creation of the virtual spaces
73 _virtual_spaces.initialize(max_low_byte_size,
74 init_low_byte_size,
75 init_high_byte_size);
76
77 // Place the young gen at the high end. Passes in the virtual space.
78 _young_gen = new ASPSYoungGen(_virtual_spaces.high(),
79 _virtual_spaces.high()->committed_size(),
80 min_high_byte_size,
81 _virtual_spaces.high_byte_size_limit());
82
83 // Place the old gen at the low end. Passes in the virtual space.
84 _old_gen = new ASPSOldGen(_virtual_spaces.low(),
85 _virtual_spaces.low()->committed_size(),
86 min_low_byte_size,
87 _virtual_spaces.low_byte_size_limit(),
88 "old", 1);
89
90 if (os::has_nvdimm()) {
91 _old_gen->setup_fd(old_young_rs.nvdimm_fd());
92 }
93 young_gen()->initialize_work();
94 assert(young_gen()->reserved().byte_size() <= young_gen()->gen_size_limit(),
95 "Consistency check");
96 assert(old_young_rs.size() >= young_gen()->gen_size_limit(),
97 "Consistency check");
98
99 old_gen()->initialize_work("old", 1);
100 assert(old_gen()->reserved().byte_size() <= old_gen()->gen_size_limit(),
101 "Consistency check");
102 assert(old_young_rs.size() >= old_gen()->gen_size_limit(),
103 "Consistency check");
104 } else {
105
106 // Layout the reserved space for the generations.
107 ReservedSpace old_rs =
108 virtual_spaces()->reserved_space().first_part(max_low_byte_size);
109 ReservedSpace heap_rs =
110 virtual_spaces()->reserved_space().last_part(max_low_byte_size);
111 ReservedSpace young_rs = heap_rs.first_part(max_high_byte_size);
112 assert(young_rs.size() == heap_rs.size(), "Didn't reserve all of the heap");
113
114 // Create the generations. Virtual spaces are not passed in.
115 _young_gen = new PSYoungGen(init_high_byte_size,
116 min_high_byte_size,
117 max_high_byte_size);
118 _old_gen = new PSOldGen(init_low_byte_size,
119 min_low_byte_size,
120 max_low_byte_size,
121 "old", 1);
122
123 // The virtual spaces are created by the initialization of the gens.
124 _young_gen->initialize(young_rs, alignment);
125 assert(young_gen()->gen_size_limit() == young_rs.size(),
126 "Consistency check");
127 if (os::has_nvdimm()) {
128 _old_gen->setup_fd(old_young_rs.nvdimm_fd());
129 old_rs.setup_fd(old_young_rs.nvdimm_fd());
130 }
131 _old_gen->initialize(old_rs, alignment, "old", 1);
132 assert(old_gen()->gen_size_limit() == old_rs.size(), "Consistency check");
133 }
134 }
135
136 size_t AdjoiningGenerations::reserved_byte_size() {
137 return virtual_spaces()->reserved_space().size();
138 }
139
140 void log_before_expansion(bool old, size_t expand_in_bytes, size_t change_in_bytes, size_t max_size) {
141 Log(heap, ergo) log;
142 if (!log.is_debug()) {
143 return;
144 }
145 log.debug("Before expansion of %s gen with boundary move", old ? "old" : "young");
146 log.debug(" Requested change: " SIZE_FORMAT_HEX " Attempted change: " SIZE_FORMAT_HEX,
147 expand_in_bytes, change_in_bytes);
148 ResourceMark rm;
149 LogStream ls(log.debug());
150 ParallelScavengeHeap::heap()->print_on(&ls);
151 log.debug(" PS%sGen max size: " SIZE_FORMAT "K", old ? "Old" : "Young", max_size/K);
152 }
153
154 void log_after_expansion(bool old, size_t max_size) {
155 Log(heap, ergo) log;
156 if (!log.is_debug()) {
157 return;
158 }
159 log.debug("After expansion of %s gen with boundary move", old ? "old" : "young");
160 ResourceMark rm;
161 LogStream ls(log.debug());
162 ParallelScavengeHeap::heap()->print_on(&ls);
163 log.debug(" PS%sGen max size: " SIZE_FORMAT "K", old ? "Old" : "Young", max_size/K);
164 }
165
166 // Make checks on the current sizes of the generations and
167 // the constraints on the sizes of the generations. Push
168 // up the boundary within the constraints. A partial
169 // push can occur.
170 void AdjoiningGenerations::request_old_gen_expansion(size_t expand_in_bytes) {
171 assert(UseAdaptiveSizePolicy && UseAdaptiveGCBoundary, "runtime check");
172
173 assert_lock_strong(ExpandHeap_lock);
174 assert_locked_or_safepoint(Heap_lock);
175
176 // These sizes limit the amount the boundaries can move. Effectively,
177 // the generation says how much it is willing to yield to the other
178 // generation.
179 const size_t young_gen_available = young_gen()->available_for_contraction();
180 const size_t old_gen_available = old_gen()->available_for_expansion();
181 const size_t alignment = virtual_spaces()->alignment();
182 size_t change_in_bytes = MIN3(young_gen_available,
183 old_gen_available,
184 align_up(expand_in_bytes, alignment));
185
186 if (change_in_bytes == 0) {
187 return;
188 }
189
190 log_before_expansion(true, expand_in_bytes, change_in_bytes, old_gen()->max_gen_size());
191
192 // Move the boundary between the generations up (smaller young gen).
193 if (virtual_spaces()->adjust_boundary_up(change_in_bytes)) {
194 young_gen()->reset_after_change();
195 old_gen()->reset_after_change();
196 }
197
198 // The total reserved for the generations should match the sum
199 // of the two even if the boundary is moving.
200 assert(reserved_byte_size() ==
201 old_gen()->max_gen_size() + young_gen()->max_size(),
202 "Space is missing");
203 young_gen()->space_invariants();
204 old_gen()->space_invariants();
205
206 log_after_expansion(true, old_gen()->max_gen_size());
207 }
208
209 // See comments on request_old_gen_expansion()
210 bool AdjoiningGenerations::request_young_gen_expansion(size_t expand_in_bytes) {
211 assert(UseAdaptiveSizePolicy && UseAdaptiveGCBoundary, "runtime check");
212
213 // If eden is not empty, the boundary can be moved but no advantage
214 // can be made of the move since eden cannot be moved.
215 if (!young_gen()->eden_space()->is_empty()) {
216 return false;
217 }
218
219
220 bool result = false;
221 const size_t young_gen_available = young_gen()->available_for_expansion();
222 const size_t old_gen_available = old_gen()->available_for_contraction();
223 const size_t alignment = virtual_spaces()->alignment();
224 size_t change_in_bytes = MIN3(young_gen_available,
225 old_gen_available,
226 align_up(expand_in_bytes, alignment));
227
228 if (change_in_bytes == 0) {
229 return false;
230 }
231
232 log_before_expansion(false, expand_in_bytes, change_in_bytes, young_gen()->max_size());
233
234 // Move the boundary between the generations down (smaller old gen).
235 MutexLocker x(ExpandHeap_lock);
236 if (virtual_spaces()->adjust_boundary_down(change_in_bytes)) {
237 young_gen()->reset_after_change();
238 old_gen()->reset_after_change();
239 result = true;
240 }
241
242 // The total reserved for the generations should match the sum
243 // of the two even if the boundary is moving.
244 assert(reserved_byte_size() ==
245 old_gen()->max_gen_size() + young_gen()->max_size(),
246 "Space is missing");
247 young_gen()->space_invariants();
248 old_gen()->space_invariants();
249
250 log_after_expansion(false, young_gen()->max_size());
251
252 return result;
253 }
254
255 // Additional space is needed in the old generation. Try to move the boundary
256 // up to meet the need. Moves boundary up only
257 void AdjoiningGenerations::adjust_boundary_for_old_gen_needs(
258 size_t desired_free_space) {
259 assert(UseAdaptiveSizePolicy && UseAdaptiveGCBoundary, "runtime check");
260
261 // Stress testing.
262 if (PSAdaptiveSizePolicyResizeVirtualSpaceAlot == 1) {
263 MutexLocker x(ExpandHeap_lock);
264 request_old_gen_expansion(virtual_spaces()->alignment() * 3 / 2);
265 }
266
267 // Expand only if the entire generation is already committed.
268 if (old_gen()->virtual_space()->uncommitted_size() == 0) {
269 if (old_gen()->free_in_bytes() < desired_free_space) {
270 MutexLocker x(ExpandHeap_lock);
271 request_old_gen_expansion(desired_free_space);
272 }
273 }
274 }
275
276 // See comment on adjust_boundary_for_old_gen_needss().
277 // Adjust boundary down only.
278 void AdjoiningGenerations::adjust_boundary_for_young_gen_needs(size_t eden_size,
279 size_t survivor_size) {
280
281 assert(UseAdaptiveSizePolicy && UseAdaptiveGCBoundary, "runtime check");
282
283 // Stress testing.
284 if (PSAdaptiveSizePolicyResizeVirtualSpaceAlot == 0) {
285 request_young_gen_expansion(virtual_spaces()->alignment() * 3 / 2);
286 eden_size = young_gen()->eden_space()->capacity_in_bytes();
287 }
288
289 // Expand only if the entire generation is already committed.
290 if (young_gen()->virtual_space()->uncommitted_size() == 0) {
291 size_t desired_size = eden_size + 2 * survivor_size;
292 const size_t committed = young_gen()->virtual_space()->committed_size();
293 if (desired_size > committed) {
294 request_young_gen_expansion(desired_size - committed);
295 }
296 }
297 }