1 /*
2 * Copyright (c) 2001, 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/concurrentG1Refine.hpp"
27 #include "gc/g1/concurrentG1RefineThread.hpp"
28 #include "gc/g1/g1YoungRemSetSamplingThread.hpp"
29 #include "logging/log.hpp"
30 #include "runtime/java.hpp"
31 #include "runtime/thread.hpp"
32 #include "utilities/debug.hpp"
33 #include "utilities/globalDefinitions.hpp"
34 #include "utilities/pair.hpp"
35 #include <math.h>
36
37 // Arbitrary but large limits, to simplify some of the zone calculations.
38 // The general idea is to allow expressions like
39 // MIN2(x OP y, max_XXX_zone)
40 // without needing to check for overflow in "x OP y", because the
41 // ranges for x and y have been restricted.
42 STATIC_ASSERT(sizeof(LP64_ONLY(jint) NOT_LP64(jshort)) <= (sizeof(size_t)/2));
43 const size_t max_yellow_zone = LP64_ONLY(max_jint) NOT_LP64(max_jshort);
44 const size_t max_green_zone = max_yellow_zone / 2;
45 const size_t max_red_zone = INT_MAX; // For dcqs.set_max_completed_queue.
46 STATIC_ASSERT(max_yellow_zone <= max_red_zone);
47
48 // Range check assertions for green zone values.
49 #define assert_zone_constraints_g(green) \
50 do { \
51 size_t azc_g_green = (green); \
52 assert(azc_g_green <= max_green_zone, \
53 "green exceeds max: " SIZE_FORMAT, azc_g_green); \
54 } while (0)
55
56 // Range check assertions for green and yellow zone values.
57 #define assert_zone_constraints_gy(green, yellow) \
58 do { \
59 size_t azc_gy_green = (green); \
60 size_t azc_gy_yellow = (yellow); \
61 assert_zone_constraints_g(azc_gy_green); \
62 assert(azc_gy_yellow <= max_yellow_zone, \
63 "yellow exceeds max: " SIZE_FORMAT, azc_gy_yellow); \
64 assert(azc_gy_green <= azc_gy_yellow, \
65 "green (" SIZE_FORMAT ") exceeds yellow (" SIZE_FORMAT ")", \
66 azc_gy_green, azc_gy_yellow); \
67 } while (0)
68
69 // Range check assertions for green, yellow, and red zone values.
70 #define assert_zone_constraints_gyr(green, yellow, red) \
71 do { \
72 size_t azc_gyr_green = (green); \
73 size_t azc_gyr_yellow = (yellow); \
74 size_t azc_gyr_red = (red); \
75 assert_zone_constraints_gy(azc_gyr_green, azc_gyr_yellow); \
76 assert(azc_gyr_red <= max_red_zone, \
77 "red exceeds max: " SIZE_FORMAT, azc_gyr_red); \
78 assert(azc_gyr_yellow <= azc_gyr_red, \
79 "yellow (" SIZE_FORMAT ") exceeds red (" SIZE_FORMAT ")", \
80 azc_gyr_yellow, azc_gyr_red); \
81 } while (0)
82
83 // Logging tag sequence for refinement control updates.
84 #define CTRL_TAGS gc, ergo, refine
85
86 // For logging zone values, ensuring consistency of level and tags.
87 #define LOG_ZONES(...) log_debug( CTRL_TAGS )(__VA_ARGS__)
88
89 // Package for pair of refinement thread activation and deactivation
90 // thresholds. The activation and deactivation levels are resp. the first
91 // and second values of the pair.
92 typedef Pair<size_t, size_t> Thresholds;
93 inline size_t activation_level(const Thresholds& t) { return t.first; }
94 inline size_t deactivation_level(const Thresholds& t) { return t.second; }
95
96 static Thresholds calc_thresholds(size_t green_zone,
97 size_t yellow_zone,
98 uint worker_i) {
99 double yellow_size = yellow_zone - green_zone;
100 double step = yellow_size / ConcurrentG1Refine::thread_num();
101 if (worker_i == 0) {
102 // Potentially activate worker 0 more aggressively, to keep
103 // available buffers near green_zone value. When yellow_size is
104 // large we don't want to allow a full step to accumulate before
105 // doing any processing, as that might lead to significantly more
106 // than green_zone buffers to be processed by update_rs.
107 step = MIN2(step, ParallelGCThreads / 2.0);
108 }
109 size_t activate_offset = static_cast<size_t>(ceil(step * (worker_i + 1)));
110 size_t deactivate_offset = static_cast<size_t>(floor(step * worker_i));
111 return Thresholds(green_zone + activate_offset,
112 green_zone + deactivate_offset);
113 }
114
115 ConcurrentG1Refine::ConcurrentG1Refine(size_t green_zone,
116 size_t yellow_zone,
117 size_t red_zone,
118 size_t min_yellow_zone_size) :
119 _threads(NULL),
120 _sample_thread(NULL),
121 _n_worker_threads(thread_num()),
122 _green_zone(green_zone),
123 _yellow_zone(yellow_zone),
124 _red_zone(red_zone),
125 _min_yellow_zone_size(min_yellow_zone_size)
126 {
127 assert_zone_constraints_gyr(green_zone, yellow_zone, red_zone);
128 }
129
130 static size_t calc_min_yellow_zone_size() {
131 size_t step = G1ConcRefinementThresholdStep;
132 uint n_workers = ConcurrentG1Refine::thread_num();
133 if ((max_yellow_zone / step) < n_workers) {
134 return max_yellow_zone;
135 } else {
136 return step * n_workers;
137 }
138 }
139
140 static size_t calc_init_green_zone() {
141 size_t green = G1ConcRefinementGreenZone;
142 if (FLAG_IS_DEFAULT(G1ConcRefinementGreenZone)) {
143 green = ParallelGCThreads;
144 }
145 return MIN2(green, max_green_zone);
146 }
147
148 static size_t calc_init_yellow_zone(size_t green, size_t min_size) {
149 size_t config = G1ConcRefinementYellowZone;
150 size_t size = 0;
151 if (FLAG_IS_DEFAULT(G1ConcRefinementYellowZone)) {
152 size = green * 2;
153 } else if (green < config) {
154 size = config - green;
155 }
156 size = MAX2(size, min_size);
157 size = MIN2(size, max_yellow_zone);
158 return MIN2(green + size, max_yellow_zone);
159 }
160
161 static size_t calc_init_red_zone(size_t green, size_t yellow) {
162 size_t size = yellow - green;
163 if (!FLAG_IS_DEFAULT(G1ConcRefinementRedZone)) {
164 size_t config = G1ConcRefinementRedZone;
165 if (yellow < config) {
166 size = MAX2(size, config - yellow);
167 }
168 }
169 return MIN2(yellow + size, max_red_zone);
170 }
171
172 ConcurrentG1Refine* ConcurrentG1Refine::create(CardTableEntryClosure* refine_closure,
173 jint* ecode) {
174 size_t min_yellow_zone_size = calc_min_yellow_zone_size();
175 size_t green_zone = calc_init_green_zone();
176 size_t yellow_zone = calc_init_yellow_zone(green_zone, min_yellow_zone_size);
177 size_t red_zone = calc_init_red_zone(green_zone, yellow_zone);
178
179 LOG_ZONES("Initial Refinement Zones: "
180 "green: " SIZE_FORMAT ", "
181 "yellow: " SIZE_FORMAT ", "
182 "red: " SIZE_FORMAT ", "
183 "min yellow size: " SIZE_FORMAT,
184 green_zone, yellow_zone, red_zone, min_yellow_zone_size);
185
186 ConcurrentG1Refine* cg1r = new ConcurrentG1Refine(green_zone,
187 yellow_zone,
188 red_zone,
189 min_yellow_zone_size);
190
191 if (cg1r == NULL) {
192 *ecode = JNI_ENOMEM;
193 vm_shutdown_during_initialization("Could not create ConcurrentG1Refine");
194 return NULL;
195 }
196
197 cg1r->_threads = NEW_C_HEAP_ARRAY_RETURN_NULL(ConcurrentG1RefineThread*, cg1r->_n_worker_threads, mtGC);
198 if (cg1r->_threads == NULL) {
199 *ecode = JNI_ENOMEM;
200 vm_shutdown_during_initialization("Could not allocate an array for ConcurrentG1RefineThread");
201 return NULL;
202 }
203
204 uint worker_id_offset = DirtyCardQueueSet::num_par_ids();
205
206 ConcurrentG1RefineThread *next = NULL;
207 for (uint i = cg1r->_n_worker_threads - 1; i != UINT_MAX; i--) {
208 Thresholds thresholds = calc_thresholds(green_zone, yellow_zone, i);
209 ConcurrentG1RefineThread* t =
210 new ConcurrentG1RefineThread(cg1r,
211 next,
212 refine_closure,
213 worker_id_offset,
214 i,
215 activation_level(thresholds),
216 deactivation_level(thresholds));
217 assert(t != NULL, "Conc refine should have been created");
218 if (t->osthread() == NULL) {
219 *ecode = JNI_ENOMEM;
220 vm_shutdown_during_initialization("Could not create ConcurrentG1RefineThread");
221 return NULL;
222 }
223
224 assert(t->cg1r() == cg1r, "Conc refine thread should refer to this");
225 cg1r->_threads[i] = t;
226 next = t;
227 }
228
229 cg1r->_sample_thread = new G1YoungRemSetSamplingThread();
230 if (cg1r->_sample_thread->osthread() == NULL) {
231 *ecode = JNI_ENOMEM;
232 vm_shutdown_during_initialization("Could not create G1YoungRemSetSamplingThread");
233 return NULL;
234 }
235
236 *ecode = JNI_OK;
237 return cg1r;
238 }
239
240 void ConcurrentG1Refine::stop() {
241 for (uint i = 0; i < _n_worker_threads; i++) {
242 _threads[i]->stop();
243 }
244 _sample_thread->stop();
245 }
246
247 void ConcurrentG1Refine::update_thread_thresholds() {
248 for (uint i = 0; i < _n_worker_threads; i++) {
249 Thresholds thresholds = calc_thresholds(_green_zone, _yellow_zone, i);
250 _threads[i]->update_thresholds(activation_level(thresholds),
251 deactivation_level(thresholds));
252 }
253 }
254
255 ConcurrentG1Refine::~ConcurrentG1Refine() {
256 for (uint i = 0; i < _n_worker_threads; i++) {
257 delete _threads[i];
258 }
259 FREE_C_HEAP_ARRAY(ConcurrentG1RefineThread*, _threads);
260
261 delete _sample_thread;
262 }
263
264 void ConcurrentG1Refine::threads_do(ThreadClosure *tc) {
265 worker_threads_do(tc);
266 tc->do_thread(_sample_thread);
267 }
268
269 void ConcurrentG1Refine::worker_threads_do(ThreadClosure * tc) {
270 for (uint i = 0; i < _n_worker_threads; i++) {
271 tc->do_thread(_threads[i]);
272 }
273 }
274
275 uint ConcurrentG1Refine::thread_num() {
276 return G1ConcRefinementThreads;
277 }
278
279 void ConcurrentG1Refine::print_worker_threads_on(outputStream* st) const {
280 for (uint i = 0; i < _n_worker_threads; ++i) {
281 _threads[i]->print_on(st);
282 st->cr();
283 }
284 _sample_thread->print_on(st);
285 st->cr();
286 }
287
288 static size_t calc_new_green_zone(size_t green,
289 double update_rs_time,
290 size_t update_rs_processed_buffers,
291 double goal_ms) {
292 // Adjust green zone based on whether we're meeting the time goal.
293 // Limit to max_green_zone.
294 const double inc_k = 1.1, dec_k = 0.9;
295 if (update_rs_time > goal_ms) {
296 if (green > 0) {
297 green = static_cast<size_t>(green * dec_k);
298 }
299 } else if (update_rs_time < goal_ms &&
300 update_rs_processed_buffers > green) {
301 green = static_cast<size_t>(MAX2(green * inc_k, green + 1.0));
302 green = MIN2(green, max_green_zone);
303 }
304 return green;
305 }
306
307 static size_t calc_new_yellow_zone(size_t green, size_t min_yellow_size) {
308 size_t size = green * 2;
309 size = MAX2(size, min_yellow_size);
310 return MIN2(green + size, max_yellow_zone);
311 }
312
313 static size_t calc_new_red_zone(size_t green, size_t yellow) {
314 return MIN2(yellow + (yellow - green), max_red_zone);
315 }
316
317 void ConcurrentG1Refine::update_zones(double update_rs_time,
318 size_t update_rs_processed_buffers,
319 double goal_ms) {
320 log_trace( CTRL_TAGS )("Updating Refinement Zones: "
321 "update_rs time: %.3fms, "
322 "update_rs buffers: " SIZE_FORMAT ", "
323 "update_rs goal time: %.3fms",
324 update_rs_time,
325 update_rs_processed_buffers,
326 goal_ms);
327
328 _green_zone = calc_new_green_zone(_green_zone,
329 update_rs_time,
330 update_rs_processed_buffers,
331 goal_ms);
332 _yellow_zone = calc_new_yellow_zone(_green_zone, _min_yellow_zone_size);
333 _red_zone = calc_new_red_zone(_green_zone, _yellow_zone);
334
335 assert_zone_constraints_gyr(_green_zone, _yellow_zone, _red_zone);
336 LOG_ZONES("Updated Refinement Zones: "
337 "green: " SIZE_FORMAT ", "
338 "yellow: " SIZE_FORMAT ", "
339 "red: " SIZE_FORMAT,
340 _green_zone, _yellow_zone, _red_zone);
341 }
342
343 void ConcurrentG1Refine::adjust(double update_rs_time,
344 size_t update_rs_processed_buffers,
345 double goal_ms) {
346 DirtyCardQueueSet& dcqs = JavaThread::dirty_card_queue_set();
347
348 if (G1UseAdaptiveConcRefinement) {
349 update_zones(update_rs_time, update_rs_processed_buffers, goal_ms);
350 update_thread_thresholds();
351
352 // Change the barrier params
353 if (_n_worker_threads == 0) {
354 // Disable dcqs notification when there are no threads to notify.
355 dcqs.set_process_completed_threshold(INT_MAX);
356 } else {
357 // Worker 0 is the primary; wakeup is via dcqs notification.
358 STATIC_ASSERT(max_yellow_zone <= INT_MAX);
359 size_t activate = _threads[0]->activation_threshold();
360 dcqs.set_process_completed_threshold((int)activate);
361 }
362 dcqs.set_max_completed_queue((int)red_zone());
363 }
364
365 size_t curr_queue_size = dcqs.completed_buffers_num();
366 if (curr_queue_size >= yellow_zone()) {
367 dcqs.set_completed_queue_padding(curr_queue_size);
368 } else {
369 dcqs.set_completed_queue_padding(0);
370 }
371 dcqs.notify_if_necessary();
372 }