1 /*
2 * Copyright (c) 2001, 2017, 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/g1ConcurrentRefine.hpp"
27 #include "gc/g1/g1ConcurrentRefineThread.hpp"
28 #include "logging/log.hpp"
29 #include "runtime/java.hpp"
30 #include "runtime/thread.hpp"
31 #include "utilities/debug.hpp"
32 #include "utilities/globalDefinitions.hpp"
33 #include "utilities/pair.hpp"
34 #include <math.h>
35
36 // Arbitrary but large limits, to simplify some of the zone calculations.
37 // The general idea is to allow expressions like
38 // MIN2(x OP y, max_XXX_zone)
39 // without needing to check for overflow in "x OP y", because the
40 // ranges for x and y have been restricted.
41 STATIC_ASSERT(sizeof(LP64_ONLY(jint) NOT_LP64(jshort)) <= (sizeof(size_t)/2));
42 const size_t max_yellow_zone = LP64_ONLY(max_jint) NOT_LP64(max_jshort);
43 const size_t max_green_zone = max_yellow_zone / 2;
44 const size_t max_red_zone = INT_MAX; // For dcqs.set_max_completed_queue.
45 STATIC_ASSERT(max_yellow_zone <= max_red_zone);
46
47 // Range check assertions for green zone values.
48 #define assert_zone_constraints_g(green) \
49 do { \
50 size_t azc_g_green = (green); \
51 assert(azc_g_green <= max_green_zone, \
52 "green exceeds max: " SIZE_FORMAT, azc_g_green); \
53 } while (0)
54
55 // Range check assertions for green and yellow zone values.
56 #define assert_zone_constraints_gy(green, yellow) \
57 do { \
58 size_t azc_gy_green = (green); \
59 size_t azc_gy_yellow = (yellow); \
60 assert_zone_constraints_g(azc_gy_green); \
61 assert(azc_gy_yellow <= max_yellow_zone, \
62 "yellow exceeds max: " SIZE_FORMAT, azc_gy_yellow); \
63 assert(azc_gy_green <= azc_gy_yellow, \
64 "green (" SIZE_FORMAT ") exceeds yellow (" SIZE_FORMAT ")", \
65 azc_gy_green, azc_gy_yellow); \
66 } while (0)
67
68 // Range check assertions for green, yellow, and red zone values.
69 #define assert_zone_constraints_gyr(green, yellow, red) \
70 do { \
71 size_t azc_gyr_green = (green); \
72 size_t azc_gyr_yellow = (yellow); \
73 size_t azc_gyr_red = (red); \
74 assert_zone_constraints_gy(azc_gyr_green, azc_gyr_yellow); \
75 assert(azc_gyr_red <= max_red_zone, \
76 "red exceeds max: " SIZE_FORMAT, azc_gyr_red); \
77 assert(azc_gyr_yellow <= azc_gyr_red, \
78 "yellow (" SIZE_FORMAT ") exceeds red (" SIZE_FORMAT ")", \
79 azc_gyr_yellow, azc_gyr_red); \
80 } while (0)
81
82 // Logging tag sequence for refinement control updates.
83 #define CTRL_TAGS gc, ergo, refine
84
85 // For logging zone values, ensuring consistency of level and tags.
86 #define LOG_ZONES(...) log_debug( CTRL_TAGS )(__VA_ARGS__)
87
88 // Package for pair of refinement thread activation and deactivation
89 // thresholds. The activation and deactivation levels are resp. the first
90 // and second values of the pair.
91 typedef Pair<size_t, size_t> Thresholds;
92 inline size_t activation_level(const Thresholds& t) { return t.first; }
93 inline size_t deactivation_level(const Thresholds& t) { return t.second; }
94
95 static Thresholds calc_thresholds(size_t green_zone,
96 size_t yellow_zone,
97 uint worker_i) {
98 double yellow_size = yellow_zone - green_zone;
99 double step = yellow_size / G1ConcurrentRefine::thread_num();
100 if (worker_i == 0) {
101 // Potentially activate worker 0 more aggressively, to keep
102 // available buffers near green_zone value. When yellow_size is
103 // large we don't want to allow a full step to accumulate before
104 // doing any processing, as that might lead to significantly more
105 // than green_zone buffers to be processed by update_rs.
106 step = MIN2(step, ParallelGCThreads / 2.0);
107 }
108 size_t activate_offset = static_cast<size_t>(ceil(step * (worker_i + 1)));
109 size_t deactivate_offset = static_cast<size_t>(floor(step * worker_i));
110 return Thresholds(green_zone + activate_offset,
111 green_zone + deactivate_offset);
112 }
113
114 G1ConcurrentRefine::G1ConcurrentRefine(size_t green_zone,
115 size_t yellow_zone,
116 size_t red_zone,
117 size_t min_yellow_zone_size) :
118 _threads(NULL),
119 _n_worker_threads(thread_num()),
120 _green_zone(green_zone),
121 _yellow_zone(yellow_zone),
122 _red_zone(red_zone),
123 _min_yellow_zone_size(min_yellow_zone_size)
124 {
125 assert_zone_constraints_gyr(green_zone, yellow_zone, red_zone);
126 }
127
128 static size_t calc_min_yellow_zone_size() {
129 size_t step = G1ConcRefinementThresholdStep;
130 uint n_workers = G1ConcurrentRefine::thread_num();
131 if ((max_yellow_zone / step) < n_workers) {
132 return max_yellow_zone;
133 } else {
134 return step * n_workers;
135 }
136 }
137
138 static size_t calc_init_green_zone() {
139 size_t green = G1ConcRefinementGreenZone;
140 if (FLAG_IS_DEFAULT(G1ConcRefinementGreenZone)) {
141 green = ParallelGCThreads;
142 }
143 return MIN2(green, max_green_zone);
144 }
145
146 static size_t calc_init_yellow_zone(size_t green, size_t min_size) {
147 size_t config = G1ConcRefinementYellowZone;
148 size_t size = 0;
149 if (FLAG_IS_DEFAULT(G1ConcRefinementYellowZone)) {
150 size = green * 2;
151 } else if (green < config) {
152 size = config - green;
153 }
154 size = MAX2(size, min_size);
155 size = MIN2(size, max_yellow_zone);
156 return MIN2(green + size, max_yellow_zone);
157 }
158
159 static size_t calc_init_red_zone(size_t green, size_t yellow) {
160 size_t size = yellow - green;
161 if (!FLAG_IS_DEFAULT(G1ConcRefinementRedZone)) {
162 size_t config = G1ConcRefinementRedZone;
163 if (yellow < config) {
164 size = MAX2(size, config - yellow);
165 }
166 }
167 return MIN2(yellow + size, max_red_zone);
168 }
169
170 G1ConcurrentRefine* G1ConcurrentRefine::create(jint* ecode) {
171 size_t min_yellow_zone_size = calc_min_yellow_zone_size();
172 size_t green_zone = calc_init_green_zone();
173 size_t yellow_zone = calc_init_yellow_zone(green_zone, min_yellow_zone_size);
174 size_t red_zone = calc_init_red_zone(green_zone, yellow_zone);
175
176 LOG_ZONES("Initial Refinement Zones: "
177 "green: " SIZE_FORMAT ", "
178 "yellow: " SIZE_FORMAT ", "
179 "red: " SIZE_FORMAT ", "
180 "min yellow size: " SIZE_FORMAT,
181 green_zone, yellow_zone, red_zone, min_yellow_zone_size);
182
183 G1ConcurrentRefine* cr = new G1ConcurrentRefine(green_zone,
184 yellow_zone,
185 red_zone,
186 min_yellow_zone_size);
187
188 if (cr == NULL) {
189 *ecode = JNI_ENOMEM;
190 vm_shutdown_during_initialization("Could not create G1ConcurrentRefine");
191 return NULL;
192 }
193
194 cr->_threads = NEW_C_HEAP_ARRAY_RETURN_NULL(G1ConcurrentRefineThread*, cr->_n_worker_threads, mtGC);
195 if (cr->_threads == NULL) {
196 *ecode = JNI_ENOMEM;
197 vm_shutdown_during_initialization("Could not allocate an array for G1ConcurrentRefineThread");
198 return NULL;
199 }
200
201 uint worker_id_offset = DirtyCardQueueSet::num_par_ids();
202
203 G1ConcurrentRefineThread *next = NULL;
204 for (uint i = cr->_n_worker_threads - 1; i != UINT_MAX; i--) {
205 Thresholds thresholds = calc_thresholds(green_zone, yellow_zone, i);
206 G1ConcurrentRefineThread* t =
207 new G1ConcurrentRefineThread(cr,
208 next,
209 worker_id_offset,
210 i,
211 activation_level(thresholds),
212 deactivation_level(thresholds));
213 assert(t != NULL, "Conc refine should have been created");
214 if (t->osthread() == NULL) {
215 *ecode = JNI_ENOMEM;
216 vm_shutdown_during_initialization("Could not create G1ConcurrentRefineThread");
217 return NULL;
218 }
219
220 assert(t->cr() == cr, "Conc refine thread should refer to this");
221 cr->_threads[i] = t;
222 next = t;
223 }
224
225 *ecode = JNI_OK;
226 return cr;
227 }
228
229 void G1ConcurrentRefine::stop() {
230 for (uint i = 0; i < _n_worker_threads; i++) {
231 _threads[i]->stop();
232 }
233 }
234
235 void G1ConcurrentRefine::update_thread_thresholds() {
236 for (uint i = 0; i < _n_worker_threads; i++) {
237 Thresholds thresholds = calc_thresholds(_green_zone, _yellow_zone, i);
238 _threads[i]->update_thresholds(activation_level(thresholds),
239 deactivation_level(thresholds));
240 }
241 }
242
243 G1ConcurrentRefine::~G1ConcurrentRefine() {
244 for (uint i = 0; i < _n_worker_threads; i++) {
245 delete _threads[i];
246 }
247 FREE_C_HEAP_ARRAY(G1ConcurrentRefineThread*, _threads);
248 }
249
250 void G1ConcurrentRefine::threads_do(ThreadClosure *tc) {
251 for (uint i = 0; i < _n_worker_threads; i++) {
252 tc->do_thread(_threads[i]);
253 }
254 }
255
256 uint G1ConcurrentRefine::thread_num() {
257 return G1ConcRefinementThreads;
258 }
259
260 void G1ConcurrentRefine::print_threads_on(outputStream* st) const {
261 for (uint i = 0; i < _n_worker_threads; ++i) {
262 _threads[i]->print_on(st);
263 st->cr();
264 }
265 }
266
267 static size_t calc_new_green_zone(size_t green,
268 double update_rs_time,
269 size_t update_rs_processed_buffers,
270 double goal_ms) {
271 // Adjust green zone based on whether we're meeting the time goal.
272 // Limit to max_green_zone.
273 const double inc_k = 1.1, dec_k = 0.9;
274 if (update_rs_time > goal_ms) {
275 if (green > 0) {
276 green = static_cast<size_t>(green * dec_k);
277 }
278 } else if (update_rs_time < goal_ms &&
279 update_rs_processed_buffers > green) {
280 green = static_cast<size_t>(MAX2(green * inc_k, green + 1.0));
281 green = MIN2(green, max_green_zone);
282 }
283 return green;
284 }
285
286 static size_t calc_new_yellow_zone(size_t green, size_t min_yellow_size) {
287 size_t size = green * 2;
288 size = MAX2(size, min_yellow_size);
289 return MIN2(green + size, max_yellow_zone);
290 }
291
292 static size_t calc_new_red_zone(size_t green, size_t yellow) {
293 return MIN2(yellow + (yellow - green), max_red_zone);
294 }
295
296 void G1ConcurrentRefine::update_zones(double update_rs_time,
297 size_t update_rs_processed_buffers,
298 double goal_ms) {
299 log_trace( CTRL_TAGS )("Updating Refinement Zones: "
300 "update_rs time: %.3fms, "
301 "update_rs buffers: " SIZE_FORMAT ", "
302 "update_rs goal time: %.3fms",
303 update_rs_time,
304 update_rs_processed_buffers,
305 goal_ms);
306
307 _green_zone = calc_new_green_zone(_green_zone,
308 update_rs_time,
309 update_rs_processed_buffers,
310 goal_ms);
311 _yellow_zone = calc_new_yellow_zone(_green_zone, _min_yellow_zone_size);
312 _red_zone = calc_new_red_zone(_green_zone, _yellow_zone);
313
314 assert_zone_constraints_gyr(_green_zone, _yellow_zone, _red_zone);
315 LOG_ZONES("Updated Refinement Zones: "
316 "green: " SIZE_FORMAT ", "
317 "yellow: " SIZE_FORMAT ", "
318 "red: " SIZE_FORMAT,
319 _green_zone, _yellow_zone, _red_zone);
320 }
321
322 void G1ConcurrentRefine::adjust(double update_rs_time,
323 size_t update_rs_processed_buffers,
324 double goal_ms) {
325 DirtyCardQueueSet& dcqs = JavaThread::dirty_card_queue_set();
326
327 if (G1UseAdaptiveConcRefinement) {
328 update_zones(update_rs_time, update_rs_processed_buffers, goal_ms);
329 update_thread_thresholds();
330
331 // Change the barrier params
332 if (_n_worker_threads == 0) {
333 // Disable dcqs notification when there are no threads to notify.
334 dcqs.set_process_completed_threshold(INT_MAX);
335 } else {
336 // Worker 0 is the primary; wakeup is via dcqs notification.
337 STATIC_ASSERT(max_yellow_zone <= INT_MAX);
338 size_t activate = _threads[0]->activation_threshold();
339 dcqs.set_process_completed_threshold((int)activate);
340 }
341 dcqs.set_max_completed_queue((int)red_zone());
342 }
343
344 size_t curr_queue_size = dcqs.completed_buffers_num();
345 if (curr_queue_size >= yellow_zone()) {
346 dcqs.set_completed_queue_padding(curr_queue_size);
347 } else {
348 dcqs.set_completed_queue_padding(0);
349 }
350 dcqs.notify_if_necessary();
351 }