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.
42STATIC_ASSERT(sizeof(LP64_ONLY(jint) NOT_LP64(jshort)) <= (sizeof(size_t)/2));
43const size_t max_yellow_zone = LP64_ONLY(max_jint) NOT_LP64(max_jshort);
44const size_t max_green_zone = max_yellow_zone / 2;
45const size_t max_red_zone = INT_MAX; // For dcqs.set_max_completed_queue.
46STATIC_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.
92typedef Pair<size_t, size_t> Thresholds;
93inline size_t activation_level(const Thresholds& t) { return t.first; }
94inline size_t deactivation_level(const Thresholds& t) { return t.second; }
95
96static 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
115ConcurrentG1Refine::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
130static 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
140static 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
148static 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
161static 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
172ConcurrentG1Refine* ConcurrentG1Refine::create(jint* ecode) {
173  size_t min_yellow_zone_size = calc_min_yellow_zone_size();
174  size_t green_zone = calc_init_green_zone();
175  size_t yellow_zone = calc_init_yellow_zone(green_zone, min_yellow_zone_size);
176  size_t red_zone = calc_init_red_zone(green_zone, yellow_zone);
177
178  LOG_ZONES("Initial Refinement Zones: "
179            "green: " SIZE_FORMAT ", "
180            "yellow: " SIZE_FORMAT ", "
181            "red: " SIZE_FORMAT ", "
182            "min yellow size: " SIZE_FORMAT,
183            green_zone, yellow_zone, red_zone, min_yellow_zone_size);
184
185  ConcurrentG1Refine* cg1r = new ConcurrentG1Refine(green_zone,
186                                                    yellow_zone,
187                                                    red_zone,
188                                                    min_yellow_zone_size);
189
190  if (cg1r == NULL) {
191    *ecode = JNI_ENOMEM;
192    vm_shutdown_during_initialization("Could not create ConcurrentG1Refine");
193    return NULL;
194  }
195
196  cg1r->_threads = NEW_C_HEAP_ARRAY_RETURN_NULL(ConcurrentG1RefineThread*, cg1r->_n_worker_threads, mtGC);
197  if (cg1r->_threads == NULL) {
198    *ecode = JNI_ENOMEM;
199    vm_shutdown_during_initialization("Could not allocate an array for ConcurrentG1RefineThread");
200    return NULL;
201  }
202
203  uint worker_id_offset = DirtyCardQueueSet::num_par_ids();
204
205  ConcurrentG1RefineThread *next = NULL;
206  for (uint i = cg1r->_n_worker_threads - 1; i != UINT_MAX; i--) {
207    Thresholds thresholds = calc_thresholds(green_zone, yellow_zone, i);
208    ConcurrentG1RefineThread* t =
209      new ConcurrentG1RefineThread(cg1r,
210                                   next,
211                                   worker_id_offset,
212                                   i,
213                                   activation_level(thresholds),
214                                   deactivation_level(thresholds));
215    assert(t != NULL, "Conc refine should have been created");
216    if (t->osthread() == NULL) {
217      *ecode = JNI_ENOMEM;
218      vm_shutdown_during_initialization("Could not create ConcurrentG1RefineThread");
219      return NULL;
220    }
221
222    assert(t->cg1r() == cg1r, "Conc refine thread should refer to this");
223    cg1r->_threads[i] = t;
224    next = t;
225  }
226
227  cg1r->_sample_thread = new G1YoungRemSetSamplingThread();
228  if (cg1r->_sample_thread->osthread() == NULL) {
229    *ecode = JNI_ENOMEM;
230    vm_shutdown_during_initialization("Could not create G1YoungRemSetSamplingThread");
231    return NULL;
232  }
233
234  *ecode = JNI_OK;
235  return cg1r;
236}
237
238void ConcurrentG1Refine::stop() {
239  for (uint i = 0; i < _n_worker_threads; i++) {
240    _threads[i]->stop();
241  }
242  _sample_thread->stop();
243}
244
245void ConcurrentG1Refine::update_thread_thresholds() {
246  for (uint i = 0; i < _n_worker_threads; i++) {
247    Thresholds thresholds = calc_thresholds(_green_zone, _yellow_zone, i);
248    _threads[i]->update_thresholds(activation_level(thresholds),
249                                   deactivation_level(thresholds));
250  }
251}
252
253ConcurrentG1Refine::~ConcurrentG1Refine() {
254  for (uint i = 0; i < _n_worker_threads; i++) {
255    delete _threads[i];
256  }
257  FREE_C_HEAP_ARRAY(ConcurrentG1RefineThread*, _threads);
258
259  delete _sample_thread;
260}
261
262void ConcurrentG1Refine::threads_do(ThreadClosure *tc) {
263  worker_threads_do(tc);
264  tc->do_thread(_sample_thread);
265}
266
267void ConcurrentG1Refine::worker_threads_do(ThreadClosure * tc) {
268  for (uint i = 0; i < _n_worker_threads; i++) {
269    tc->do_thread(_threads[i]);
270  }
271}
272
273uint ConcurrentG1Refine::thread_num() {
274  return G1ConcRefinementThreads;
275}
276
277void ConcurrentG1Refine::print_worker_threads_on(outputStream* st) const {
278  for (uint i = 0; i < _n_worker_threads; ++i) {
279    _threads[i]->print_on(st);
280    st->cr();
281  }
282  _sample_thread->print_on(st);
283  st->cr();
284}
285
286static size_t calc_new_green_zone(size_t green,
287                                  double update_rs_time,
288                                  size_t update_rs_processed_buffers,
289                                  double goal_ms) {
290  // Adjust green zone based on whether we're meeting the time goal.
291  // Limit to max_green_zone.
292  const double inc_k = 1.1, dec_k = 0.9;
293  if (update_rs_time > goal_ms) {
294    if (green > 0) {
295      green = static_cast<size_t>(green * dec_k);
296    }
297  } else if (update_rs_time < goal_ms &&
298             update_rs_processed_buffers > green) {
299    green = static_cast<size_t>(MAX2(green * inc_k, green + 1.0));
300    green = MIN2(green, max_green_zone);
301  }
302  return green;
303}
304
305static size_t calc_new_yellow_zone(size_t green, size_t min_yellow_size) {
306  size_t size = green * 2;
307  size = MAX2(size, min_yellow_size);
308  return MIN2(green + size, max_yellow_zone);
309}
310
311static size_t calc_new_red_zone(size_t green, size_t yellow) {
312  return MIN2(yellow + (yellow - green), max_red_zone);
313}
314
315void ConcurrentG1Refine::update_zones(double update_rs_time,
316                                      size_t update_rs_processed_buffers,
317                                      double goal_ms) {
318  log_trace( CTRL_TAGS )("Updating Refinement Zones: "
319                         "update_rs time: %.3fms, "
320                         "update_rs buffers: " SIZE_FORMAT ", "
321                         "update_rs goal time: %.3fms",
322                         update_rs_time,
323                         update_rs_processed_buffers,
324                         goal_ms);
325
326  _green_zone = calc_new_green_zone(_green_zone,
327                                    update_rs_time,
328                                    update_rs_processed_buffers,
329                                    goal_ms);
330  _yellow_zone = calc_new_yellow_zone(_green_zone, _min_yellow_zone_size);
331  _red_zone = calc_new_red_zone(_green_zone, _yellow_zone);
332
333  assert_zone_constraints_gyr(_green_zone, _yellow_zone, _red_zone);
334  LOG_ZONES("Updated Refinement Zones: "
335            "green: " SIZE_FORMAT ", "
336            "yellow: " SIZE_FORMAT ", "
337            "red: " SIZE_FORMAT,
338            _green_zone, _yellow_zone, _red_zone);
339}
340
341void ConcurrentG1Refine::adjust(double update_rs_time,
342                                size_t update_rs_processed_buffers,
343                                double goal_ms) {
344  DirtyCardQueueSet& dcqs = JavaThread::dirty_card_queue_set();
345
346  if (G1UseAdaptiveConcRefinement) {
347    update_zones(update_rs_time, update_rs_processed_buffers, goal_ms);
348    update_thread_thresholds();
349
350    // Change the barrier params
351    if (_n_worker_threads == 0) {
352      // Disable dcqs notification when there are no threads to notify.
353      dcqs.set_process_completed_threshold(INT_MAX);
354    } else {
355      // Worker 0 is the primary; wakeup is via dcqs notification.
356      STATIC_ASSERT(max_yellow_zone <= INT_MAX);
357      size_t activate = _threads[0]->activation_threshold();
358      dcqs.set_process_completed_threshold((int)activate);
359    }
360    dcqs.set_max_completed_queue((int)red_zone());
361  }
362
363  size_t curr_queue_size = dcqs.completed_buffers_num();
364  if (curr_queue_size >= yellow_zone()) {
365    dcqs.set_completed_queue_padding(curr_queue_size);
366  } else {
367    dcqs.set_completed_queue_padding(0);
368  }
369  dcqs.notify_if_necessary();
370}
371