1 /*
2 * Copyright (c) 2010, 2024, 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 "cds/classPreloader.hpp"
27 #include "code/scopeDesc.hpp"
28 #include "code/SCCache.hpp"
29 #include "compiler/compilationPolicy.hpp"
30 #include "compiler/compileBroker.hpp"
31 #include "compiler/compilerDefinitions.inline.hpp"
32 #include "compiler/compilerOracle.hpp"
33 #include "memory/resourceArea.hpp"
34 #include "oops/methodData.hpp"
35 #include "oops/method.inline.hpp"
36 #include "oops/oop.inline.hpp"
37 #include "oops/trainingData.hpp"
38 #include "prims/jvmtiExport.hpp"
39 #include "runtime/arguments.hpp"
40 #include "runtime/deoptimization.hpp"
41 #include "runtime/frame.hpp"
42 #include "runtime/frame.inline.hpp"
43 #include "runtime/globals_extension.hpp"
44 #include "runtime/handles.inline.hpp"
45 #include "runtime/safepoint.hpp"
46 #include "runtime/safepointVerifiers.hpp"
47 #ifdef COMPILER1
48 #include "c1/c1_Compiler.hpp"
49 #endif
50 #ifdef COMPILER2
51 #include "opto/c2compiler.hpp"
52 #endif
53 #if INCLUDE_JVMCI
54 #include "jvmci/jvmci.hpp"
55 #endif
56
57 int64_t CompilationPolicy::_start_time = 0;
58 int CompilationPolicy::_c1_count = 0;
59 int CompilationPolicy::_c2_count = 0;
60 int CompilationPolicy::_c3_count = 0;
61 int CompilationPolicy::_sc_count = 0;
62 double CompilationPolicy::_increase_threshold_at_ratio = 0;
63
64 CompilationPolicy::LoadAverage CompilationPolicy::_load_average;
65 CompilationPolicy::TrainingReplayQueue CompilationPolicy::_training_replay_queue;
66 volatile bool CompilationPolicy::_recompilation_done = false;
67
68 void compilationPolicy_init() {
69 CompilationPolicy::initialize();
70 }
71
72 int CompilationPolicy::compiler_count(CompLevel comp_level) {
73 if (is_c1_compile(comp_level)) {
74 return c1_count();
75 } else if (is_c2_compile(comp_level)) {
76 return c2_count();
77 }
78 return 0;
79 }
80
81 void CompilationPolicy::sample_load_average() {
82 const int c2_queue_size = CompileBroker::queue_size(CompLevel_full_optimization);
83 _load_average.sample(c2_queue_size);
84 }
85
86 bool CompilationPolicy::have_recompilation_work() {
87 if (UseRecompilation && TrainingData::have_data() && TrainingData::have_recompilation_schedule() &&
88 TrainingData::recompilation_schedule()->length() > 0 && !_recompilation_done) {
89 if (_load_average.value() <= RecompilationLoadAverageThreshold) {
90 return true;
91 }
92 }
93 return false;
94 }
95
96 bool CompilationPolicy::recompilation_step(int step, TRAPS) {
97 if (!have_recompilation_work() || os::elapsedTime() < DelayRecompilation) {
98 return false;
99 }
100
101 const int size = TrainingData::recompilation_schedule()->length();
102 int i = 0;
103 int count = 0;
104 bool repeat = false;
105 for (; i < size && count < step; i++) {
106 if (!TrainingData::recompilation_status()[i]) {
107 MethodTrainingData* mtd = TrainingData::recompilation_schedule()->at(i);
108 if (!mtd->has_holder()) {
109 Atomic::release_store(&TrainingData::recompilation_status()[i], true);
110 continue;
111 }
112 const Method* method = mtd->holder();
113 InstanceKlass* klass = method->method_holder();
114 if (klass->is_not_initialized()) {
115 repeat = true;
116 continue;
117 }
118 nmethod *nm = method->code();
119 if (nm == nullptr) {
120 repeat = true;
121 continue;
122 }
123
124 if (!ForceRecompilation && !(nm->is_scc() && nm->comp_level() == CompLevel_full_optimization)) {
125 // If it's already online-compiled at level 4, mark it as done.
126 if (nm->comp_level() == CompLevel_full_optimization) {
127 Atomic::store(&TrainingData::recompilation_status()[i], true);
128 } else {
129 repeat = true;
130 }
131 continue;
132 }
133 if (Atomic::cmpxchg(&TrainingData::recompilation_status()[i], false, true) == false) {
134 const methodHandle m(THREAD, const_cast<Method*>(method));
135 CompLevel next_level = CompLevel_full_optimization;
136
137 if (method->method_data() == nullptr) {
138 create_mdo(m, THREAD);
139 }
140
141 if (PrintTieredEvents) {
142 print_event(FORCE_RECOMPILE, m(), m(), InvocationEntryBci, next_level);
143 }
144 CompileBroker::compile_method(m, InvocationEntryBci, CompLevel_full_optimization, methodHandle(), 0,
145 true /*requires_online_compilation*/, CompileTask::Reason_MustBeCompiled, THREAD);
146 if (HAS_PENDING_EXCEPTION) {
147 CLEAR_PENDING_EXCEPTION;
148 }
149 count++;
150 }
151 }
152 }
153
154 if (i == size && !repeat) {
155 Atomic::release_store(&_recompilation_done, true);
156 }
157 return count > 0;
158 }
159
160 // Returns true if m must be compiled before executing it
161 // This is intended to force compiles for methods (usually for
162 // debugging) that would otherwise be interpreted for some reason.
163 bool CompilationPolicy::must_be_compiled(const methodHandle& m, int comp_level) {
164 // Don't allow Xcomp to cause compiles in replay mode
165 if (ReplayCompiles) return false;
166
167 if (m->has_compiled_code()) return false; // already compiled
168 if (!can_be_compiled(m, comp_level)) return false;
169
170 return !UseInterpreter || // must compile all methods
171 (AlwaysCompileLoopMethods && m->has_loops() && CompileBroker::should_compile_new_jobs()); // eagerly compile loop methods
172 }
173
174 void CompilationPolicy::maybe_compile_early(const methodHandle& m, TRAPS) {
175 if (m->method_holder()->is_not_initialized()) {
176 // 'is_not_initialized' means not only '!is_initialized', but also that
177 // initialization has not been started yet ('!being_initialized')
178 // Do not force compilation of methods in uninitialized classes.
179 return;
180 }
181 if (!m->is_native() && MethodTrainingData::have_data()) {
182 MethodTrainingData* mtd = MethodTrainingData::find(m);
183 if (mtd == nullptr) {
184 return; // there is no training data recorded for m
185 }
186 bool recompile = m->code_has_clinit_barriers();
187 CompLevel cur_level = static_cast<CompLevel>(m->highest_comp_level());
188 CompLevel next_level = trained_transition(m, cur_level, mtd, THREAD);
189 if ((next_level != cur_level || recompile) && can_be_compiled(m, next_level) && !CompileBroker::compilation_is_in_queue(m)) {
190 bool requires_online_compilation = false;
191 CompileTrainingData* ctd = mtd->last_toplevel_compile(next_level);
192 if (ctd != nullptr) {
193 requires_online_compilation = (ctd->init_deps_left() > 0);
194 }
195 if (requires_online_compilation && recompile) {
196 return;
197 }
198 if (PrintTieredEvents) {
199 print_event(FORCE_COMPILE, m(), m(), InvocationEntryBci, next_level);
200 }
201 CompileBroker::compile_method(m, InvocationEntryBci, next_level, methodHandle(), 0, requires_online_compilation, CompileTask::Reason_MustBeCompiled, THREAD);
202 if (HAS_PENDING_EXCEPTION) {
203 CLEAR_PENDING_EXCEPTION;
204 }
205 }
206 }
207 }
208
209 void CompilationPolicy::maybe_compile_early_after_init(const methodHandle& m, TRAPS) {
210 assert(m->method_holder()->is_initialized(), "Should be called after class initialization");
211 maybe_compile_early(m, THREAD);
212 }
213
214 void CompilationPolicy::compile_if_required(const methodHandle& m, TRAPS) {
215 if (!THREAD->can_call_java() || THREAD->is_Compiler_thread()) {
216 // don't force compilation, resolve was on behalf of compiler
217 return;
218 }
219 if (m->method_holder()->is_not_initialized()) {
220 // 'is_not_initialized' means not only '!is_initialized', but also that
221 // initialization has not been started yet ('!being_initialized')
222 // Do not force compilation of methods in uninitialized classes.
223 // Note that doing this would throw an assert later,
224 // in CompileBroker::compile_method.
225 // We sometimes use the link resolver to do reflective lookups
226 // even before classes are initialized.
227 return;
228 }
229
230 if (must_be_compiled(m)) {
231 // This path is unusual, mostly used by the '-Xcomp' stress test mode.
232 CompLevel level = initial_compile_level(m);
233 if (PrintTieredEvents) {
234 print_event(FORCE_COMPILE, m(), m(), InvocationEntryBci, level);
235 }
236 CompileBroker::compile_method(m, InvocationEntryBci, level, methodHandle(), 0, false, CompileTask::Reason_MustBeCompiled, THREAD);
237 }
238 }
239
240 void CompilationPolicy::replay_training_at_init_impl(InstanceKlass* klass, TRAPS) {
241 if (!klass->has_init_deps_processed()) {
242 ResourceMark rm;
243 log_debug(training)("Replay training: %s", klass->external_name());
244
245 KlassTrainingData* ktd = KlassTrainingData::find(klass);
246 if (ktd != nullptr) {
247 guarantee(ktd->has_holder(), "");
248 ktd->notice_fully_initialized(); // sets klass->has_init_deps_processed bit
249 assert(klass->has_init_deps_processed(), "");
250
251 ktd->iterate_all_comp_deps([&](CompileTrainingData* ctd) {
252 if (ctd->init_deps_left() == 0) {
253 MethodTrainingData* mtd = ctd->method();
254 if (mtd->has_holder()) {
255 const methodHandle mh(THREAD, const_cast<Method*>(mtd->holder()));
256 CompilationPolicy::maybe_compile_early(mh, THREAD);
257 }
258 }
259 });
260 }
261 Array<Method*>* methods = klass->methods();
262 for (int i = 0; i < methods->length(); i++) {
263 const methodHandle mh(THREAD, methods->at(i));
264 CompilationPolicy::maybe_compile_early_after_init(mh, THREAD);
265 }
266 }
267 }
268
269 void CompilationPolicy::replay_training_at_init(bool is_on_shutdown, TRAPS) {
270 // Drain pending queue when no concurrent processing thread is present.
271 if (UseConcurrentTrainingReplay) {
272 if (VerifyTrainingData) {
273 MonitorLocker locker(THREAD, TrainingReplayQueue_lock);
274 while (!_training_replay_queue.is_empty_unlocked()) {
275 locker.wait(); // let the replay training thread drain the queue
276 }
277 }
278 } else {
279 do {
280 InstanceKlass* pending = _training_replay_queue.try_pop(TrainingReplayQueue_lock, THREAD);
281 if (pending == nullptr) {
282 break; // drained the queue
283 }
284 if (is_on_shutdown) {
285 LogStreamHandle(Warning, training) log;
286 if (log.is_enabled()) {
287 ResourceMark rm;
288 log.print("pending training replay request: %s%s",
289 pending->external_name(), (pending->has_preinitialized_mirror() ? " (preinitialized)" : ""));
290 }
291 }
292 replay_training_at_init_impl(pending, THREAD);
293 } while (true);
294 }
295
296 if (VerifyTrainingData) {
297 TrainingData::verify();
298 }
299 }
300
301 void CompilationPolicy::replay_training_at_init(InstanceKlass* klass, TRAPS) {
302 assert(klass->is_initialized(), "");
303 if (TrainingData::have_data() && klass->is_shared() &&
304 (CompileBroker::replay_initialized() || !klass->has_preinitialized_mirror())) { // ignore preloaded classes during early startup
305 if (UseConcurrentTrainingReplay || !CompileBroker::replay_initialized()) {
306 _training_replay_queue.push(klass, TrainingReplayQueue_lock, THREAD);
307 } else {
308 replay_training_at_init_impl(klass, THREAD);
309 }
310 assert(!HAS_PENDING_EXCEPTION, "");
311 }
312 }
313
314 // For TrainingReplayQueue
315 template<>
316 void CompilationPolicyUtils::Queue<InstanceKlass>::print_on(outputStream* st) {
317 int pos = 0;
318 for (QueueNode* cur = _head; cur != nullptr; cur = cur->next()) {
319 ResourceMark rm;
320 InstanceKlass* ik = cur->value();
321 st->print_cr("%3d: " INTPTR_FORMAT " %s", ++pos, p2i(ik), ik->external_name());
322 }
323 }
324
325 void CompilationPolicy::replay_training_at_init_loop(TRAPS) {
326 precond(UseConcurrentTrainingReplay);
327
328 while (!CompileBroker::is_compilation_disabled_forever() || VerifyTrainingData) {
329 InstanceKlass* ik = _training_replay_queue.pop(TrainingReplayQueue_lock, THREAD);
330 replay_training_at_init_impl(ik, THREAD);
331 }
332 }
333
334 static inline CompLevel adjust_level_for_compilability_query(CompLevel comp_level) {
335 if (comp_level == CompLevel_any) {
336 if (CompilerConfig::is_c1_only()) {
337 comp_level = CompLevel_simple;
338 } else if (CompilerConfig::is_c2_or_jvmci_compiler_only()) {
339 comp_level = CompLevel_full_optimization;
340 }
341 }
342 return comp_level;
343 }
344
345 // Returns true if m is allowed to be compiled
346 bool CompilationPolicy::can_be_compiled(const methodHandle& m, int comp_level) {
347 // allow any levels for WhiteBox
348 assert(WhiteBoxAPI || comp_level == CompLevel_any || is_compile(comp_level), "illegal compilation level %d", comp_level);
349
350 if (m->is_abstract()) return false;
351 if (DontCompileHugeMethods && m->code_size() > HugeMethodLimit) return false;
352
353 // Math intrinsics should never be compiled as this can lead to
354 // monotonicity problems because the interpreter will prefer the
355 // compiled code to the intrinsic version. This can't happen in
356 // production because the invocation counter can't be incremented
357 // but we shouldn't expose the system to this problem in testing
358 // modes.
359 if (!AbstractInterpreter::can_be_compiled(m)) {
360 return false;
361 }
362 comp_level = adjust_level_for_compilability_query((CompLevel) comp_level);
363 if (comp_level == CompLevel_any || is_compile(comp_level)) {
364 return !m->is_not_compilable(comp_level);
365 }
366 return false;
367 }
368
369 // Returns true if m is allowed to be osr compiled
370 bool CompilationPolicy::can_be_osr_compiled(const methodHandle& m, int comp_level) {
371 bool result = false;
372 comp_level = adjust_level_for_compilability_query((CompLevel) comp_level);
373 if (comp_level == CompLevel_any || is_compile(comp_level)) {
374 result = !m->is_not_osr_compilable(comp_level);
375 }
376 return (result && can_be_compiled(m, comp_level));
377 }
378
379 bool CompilationPolicy::is_compilation_enabled() {
380 // NOTE: CompileBroker::should_compile_new_jobs() checks for UseCompiler
381 return CompileBroker::should_compile_new_jobs();
382 }
383
384 CompileTask* CompilationPolicy::select_task_helper(CompileQueue* compile_queue) {
385 // Remove unloaded methods from the queue
386 for (CompileTask* task = compile_queue->first(); task != nullptr; ) {
387 CompileTask* next = task->next();
388 if (task->is_unloaded()) {
389 compile_queue->remove_and_mark_stale(task);
390 }
391 task = next;
392 }
393 #if INCLUDE_JVMCI
394 if (UseJVMCICompiler && !BackgroundCompilation) {
395 /*
396 * In blocking compilation mode, the CompileBroker will make
397 * compilations submitted by a JVMCI compiler thread non-blocking. These
398 * compilations should be scheduled after all blocking compilations
399 * to service non-compiler related compilations sooner and reduce the
400 * chance of such compilations timing out.
401 */
402 for (CompileTask* task = compile_queue->first(); task != nullptr; task = task->next()) {
403 if (task->is_blocking()) {
404 return task;
405 }
406 }
407 }
408 #endif
409 return compile_queue->first();
410 }
411
412 // Simple methods are as good being compiled with C1 as C2.
413 // Determine if a given method is such a case.
414 bool CompilationPolicy::is_trivial(const methodHandle& method) {
415 if (method->is_accessor() ||
416 method->is_constant_getter()) {
417 return true;
418 }
419 return false;
420 }
421
422 bool CompilationPolicy::force_comp_at_level_simple(const methodHandle& method) {
423 if (CompilationModeFlag::quick_internal()) {
424 #if INCLUDE_JVMCI
425 if (UseJVMCICompiler) {
426 AbstractCompiler* comp = CompileBroker::compiler(CompLevel_full_optimization);
427 if (comp != nullptr && comp->is_jvmci() && ((JVMCICompiler*) comp)->force_comp_at_level_simple(method)) {
428 return !SCCache::is_C3_on();
429 }
430 }
431 #endif
432 }
433 return false;
434 }
435
436 CompLevel CompilationPolicy::comp_level(Method* method) {
437 nmethod *nm = method->code();
438 if (nm != nullptr && nm->is_in_use()) {
439 return (CompLevel)nm->comp_level();
440 }
441 return CompLevel_none;
442 }
443
444 // Call and loop predicates determine whether a transition to a higher
445 // compilation level should be performed (pointers to predicate functions
446 // are passed to common()).
447 // Tier?LoadFeedback is basically a coefficient that determines of
448 // how many methods per compiler thread can be in the queue before
449 // the threshold values double.
450 class LoopPredicate : AllStatic {
451 public:
452 static bool apply_scaled(const methodHandle& method, CompLevel cur_level, int i, int b, double scale) {
453 double threshold_scaling;
454 if (CompilerOracle::has_option_value(method, CompileCommandEnum::CompileThresholdScaling, threshold_scaling)) {
455 scale *= threshold_scaling;
456 }
457 switch(cur_level) {
458 case CompLevel_none:
459 case CompLevel_limited_profile:
460 return b >= Tier3BackEdgeThreshold * scale;
461 case CompLevel_full_profile:
462 return b >= Tier4BackEdgeThreshold * scale;
463 default:
464 return true;
465 }
466 }
467
468 static bool apply(const methodHandle& method, CompLevel cur_level, int i, int b) {
469 double k = 1;
470 switch(cur_level) {
471 case CompLevel_none:
472 // Fall through
473 case CompLevel_limited_profile: {
474 k = CompilationPolicy::threshold_scale(CompLevel_full_profile, Tier3LoadFeedback);
475 break;
476 }
477 case CompLevel_full_profile: {
478 k = CompilationPolicy::threshold_scale(CompLevel_full_optimization, Tier4LoadFeedback);
479 break;
480 }
481 default:
482 return true;
483 }
484 return apply_scaled(method, cur_level, i, b, k);
485 }
486 };
487
488 class CallPredicate : AllStatic {
489 public:
490 static bool apply_scaled(const methodHandle& method, CompLevel cur_level, int i, int b, double scale) {
491 double threshold_scaling;
492 if (CompilerOracle::has_option_value(method, CompileCommandEnum::CompileThresholdScaling, threshold_scaling)) {
493 scale *= threshold_scaling;
494 }
495 switch(cur_level) {
496 case CompLevel_none:
497 case CompLevel_limited_profile:
498 return (i >= Tier3InvocationThreshold * scale) ||
499 (i >= Tier3MinInvocationThreshold * scale && i + b >= Tier3CompileThreshold * scale);
500 case CompLevel_full_profile:
501 return (i >= Tier4InvocationThreshold * scale) ||
502 (i >= Tier4MinInvocationThreshold * scale && i + b >= Tier4CompileThreshold * scale);
503 default:
504 return true;
505 }
506 }
507
508 static bool apply(const methodHandle& method, CompLevel cur_level, int i, int b) {
509 double k = 1;
510 switch(cur_level) {
511 case CompLevel_none:
512 case CompLevel_limited_profile: {
513 k = CompilationPolicy::threshold_scale(CompLevel_full_profile, Tier3LoadFeedback);
514 break;
515 }
516 case CompLevel_full_profile: {
517 k = CompilationPolicy::threshold_scale(CompLevel_full_optimization, Tier4LoadFeedback);
518 break;
519 }
520 default:
521 return true;
522 }
523 return apply_scaled(method, cur_level, i, b, k);
524 }
525 };
526
527 double CompilationPolicy::threshold_scale(CompLevel level, int feedback_k) {
528 int comp_count = compiler_count(level);
529 if (comp_count > 0) {
530 double queue_size = CompileBroker::queue_size(level);
531 double k = (double)queue_size / ((double)feedback_k * (double)comp_count) + 1;
532
533 // Increase C1 compile threshold when the code cache is filled more
534 // than specified by IncreaseFirstTierCompileThresholdAt percentage.
535 // The main intention is to keep enough free space for C2 compiled code
536 // to achieve peak performance if the code cache is under stress.
537 if (CompilerConfig::is_tiered() && !CompilationModeFlag::disable_intermediate() && is_c1_compile(level)) {
538 double current_reverse_free_ratio = CodeCache::reverse_free_ratio();
539 if (current_reverse_free_ratio > _increase_threshold_at_ratio) {
540 k *= exp(current_reverse_free_ratio - _increase_threshold_at_ratio);
541 }
542 }
543 return k;
544 }
545 return 1;
546 }
547
548 void CompilationPolicy::print_counters(const char* prefix, Method* m) {
549 int invocation_count = m->invocation_count();
550 int backedge_count = m->backedge_count();
551 MethodData* mdh = m->method_data();
552 int mdo_invocations = 0, mdo_backedges = 0;
553 int mdo_invocations_start = 0, mdo_backedges_start = 0;
554 if (mdh != nullptr) {
555 mdo_invocations = mdh->invocation_count();
556 mdo_backedges = mdh->backedge_count();
557 mdo_invocations_start = mdh->invocation_count_start();
558 mdo_backedges_start = mdh->backedge_count_start();
559 }
560 tty->print(" %stotal=%d,%d %smdo=%d(%d),%d(%d)", prefix,
561 invocation_count, backedge_count, prefix,
562 mdo_invocations, mdo_invocations_start,
563 mdo_backedges, mdo_backedges_start);
564 tty->print(" %smax levels=%d,%d", prefix,
565 m->highest_comp_level(), m->highest_osr_comp_level());
566 }
567
568 void CompilationPolicy::print_training_data(const char* prefix, Method* method) {
569 methodHandle m(Thread::current(), method);
570 tty->print(" %smtd: ", prefix);
571 MethodTrainingData* mtd = MethodTrainingData::find(m);
572 if (mtd == nullptr) {
573 tty->print("null");
574 } else {
575 MethodData* md = mtd->final_profile();
576 tty->print("mdo=");
577 if (md == nullptr) {
578 tty->print("null");
579 } else {
580 int mdo_invocations = md->invocation_count();
581 int mdo_backedges = md->backedge_count();
582 int mdo_invocations_start = md->invocation_count_start();
583 int mdo_backedges_start = md->backedge_count_start();
584 tty->print("%d(%d), %d(%d)", mdo_invocations, mdo_invocations_start, mdo_backedges, mdo_backedges_start);
585 }
586 CompileTrainingData* ctd = mtd->last_toplevel_compile(CompLevel_full_optimization);
587 tty->print(", deps=");
588 if (ctd == nullptr) {
589 tty->print("null");
590 } else {
591 tty->print("%d", ctd->init_deps_left());
592 }
593 }
594 }
595
596 // Print an event.
597 void CompilationPolicy::print_event(EventType type, Method* m, Method* im, int bci, CompLevel level) {
598 bool inlinee_event = m != im;
599
600 ttyLocker tty_lock;
601 tty->print("%lf: [", os::elapsedTime());
602
603 switch(type) {
604 case CALL:
605 tty->print("call");
606 break;
607 case LOOP:
608 tty->print("loop");
609 break;
610 case COMPILE:
611 tty->print("compile");
612 break;
613 case FORCE_COMPILE:
614 tty->print("force-compile");
615 break;
616 case FORCE_RECOMPILE:
617 tty->print("force-recompile");
618 break;
619 case REMOVE_FROM_QUEUE:
620 tty->print("remove-from-queue");
621 break;
622 case UPDATE_IN_QUEUE:
623 tty->print("update-in-queue");
624 break;
625 case REPROFILE:
626 tty->print("reprofile");
627 break;
628 case MAKE_NOT_ENTRANT:
629 tty->print("make-not-entrant");
630 break;
631 default:
632 tty->print("unknown");
633 }
634
635 tty->print(" level=%d ", level);
636
637 ResourceMark rm;
638 char *method_name = m->name_and_sig_as_C_string();
639 tty->print("[%s", method_name);
640 if (inlinee_event) {
641 char *inlinee_name = im->name_and_sig_as_C_string();
642 tty->print(" [%s]] ", inlinee_name);
643 }
644 else tty->print("] ");
645 tty->print("@%d queues=%d,%d", bci, CompileBroker::queue_size(CompLevel_full_profile),
646 CompileBroker::queue_size(CompLevel_full_optimization));
647
648 tty->print(" rate=");
649 if (m->prev_time() == 0) tty->print("n/a");
650 else tty->print("%f", m->rate());
651 tty->print(" load=%lf", _load_average.value());
652
653 tty->print(" k=%.2lf,%.2lf", threshold_scale(CompLevel_full_profile, Tier3LoadFeedback),
654 threshold_scale(CompLevel_full_optimization, Tier4LoadFeedback));
655
656 if (type != COMPILE) {
657 print_counters("", m);
658 if (inlinee_event) {
659 print_counters("inlinee ", im);
660 }
661 tty->print(" compilable=");
662 bool need_comma = false;
663 if (!m->is_not_compilable(CompLevel_full_profile)) {
664 tty->print("c1");
665 need_comma = true;
666 }
667 if (!m->is_not_osr_compilable(CompLevel_full_profile)) {
668 if (need_comma) tty->print(",");
669 tty->print("c1-osr");
670 need_comma = true;
671 }
672 if (!m->is_not_compilable(CompLevel_full_optimization)) {
673 if (need_comma) tty->print(",");
674 tty->print("c2");
675 need_comma = true;
676 }
677 if (!m->is_not_osr_compilable(CompLevel_full_optimization)) {
678 if (need_comma) tty->print(",");
679 tty->print("c2-osr");
680 }
681 tty->print(" status=");
682 if (m->queued_for_compilation()) {
683 tty->print("in-queue");
684 } else tty->print("idle");
685 print_training_data("", m);
686 if (inlinee_event) {
687 print_training_data("inlinee ", im);
688 }
689 }
690 tty->print_cr("]");
691 }
692
693 void CompilationPolicy::initialize() {
694 if (!CompilerConfig::is_interpreter_only()) {
695 int count = CICompilerCount;
696 bool c1_only = CompilerConfig::is_c1_only();
697 bool c2_only = CompilerConfig::is_c2_or_jvmci_compiler_only();
698
699 #ifdef _LP64
700 // Turn on ergonomic compiler count selection
701 if (FLAG_IS_DEFAULT(CICompilerCountPerCPU) && FLAG_IS_DEFAULT(CICompilerCount)) {
702 FLAG_SET_DEFAULT(CICompilerCountPerCPU, true);
703 }
704 if (CICompilerCountPerCPU) {
705 // Simple log n seems to grow too slowly for tiered, try something faster: log n * log log n
706 int log_cpu = log2i(os::active_processor_count());
707 int loglog_cpu = log2i(MAX2(log_cpu, 1));
708 count = MAX2(log_cpu * loglog_cpu * 3 / 2, 2);
709 // Make sure there is enough space in the code cache to hold all the compiler buffers
710 size_t c1_size = 0;
711 #ifdef COMPILER1
712 c1_size = Compiler::code_buffer_size();
713 #endif
714 size_t c2_size = 0;
715 #ifdef COMPILER2
716 c2_size = C2Compiler::initial_code_buffer_size();
717 #endif
718 size_t buffer_size = c1_only ? c1_size : (c1_size/3 + 2*c2_size/3);
719 int max_count = (ReservedCodeCacheSize - (CodeCacheMinimumUseSpace DEBUG_ONLY(* 3))) / (int)buffer_size;
720 if (count > max_count) {
721 // Lower the compiler count such that all buffers fit into the code cache
722 count = MAX2(max_count, c1_only ? 1 : 2);
723 }
724 FLAG_SET_ERGO(CICompilerCount, count);
725 }
726 #else
727 // On 32-bit systems, the number of compiler threads is limited to 3.
728 // On these systems, the virtual address space available to the JVM
729 // is usually limited to 2-4 GB (the exact value depends on the platform).
730 // As the compilers (especially C2) can consume a large amount of
731 // memory, scaling the number of compiler threads with the number of
732 // available cores can result in the exhaustion of the address space
733 /// available to the VM and thus cause the VM to crash.
734 if (FLAG_IS_DEFAULT(CICompilerCount)) {
735 count = 3;
736 FLAG_SET_ERGO(CICompilerCount, count);
737 }
738 #endif
739
740 if (c1_only) {
741 // No C2 compiler thread required
742 set_c1_count(count);
743 } else if (c2_only) {
744 set_c2_count(count);
745 } else {
746 #if INCLUDE_JVMCI
747 if (UseJVMCICompiler && UseJVMCINativeLibrary) {
748 int libjvmci_count = MAX2((int) (count * JVMCINativeLibraryThreadFraction), 1);
749 int c1_count = MAX2(count - libjvmci_count, 1);
750 set_c2_count(libjvmci_count);
751 set_c1_count(c1_count);
752 } else if (SCCache::is_C3_on()) {
753 set_c1_count(MAX2(count / 3, 1));
754 set_c2_count(MAX2(count - c1_count(), 1));
755 set_c3_count(1);
756 } else
757 #endif
758 {
759 set_c1_count(MAX2(count / 3, 1));
760 set_c2_count(MAX2(count - c1_count(), 1));
761 }
762 if (SCCache::is_code_load_thread_on()) {
763 set_sc_count((c1_only || c2_only) ? 1 : 2); // At minimum we need 2 threads to load C1 and C2 cached code in parallel
764 }
765 }
766 assert(count == c1_count() + c2_count(), "inconsistent compiler thread count");
767 set_increase_threshold_at_ratio();
768 }
769
770 set_start_time(nanos_to_millis(os::javaTimeNanos()));
771 }
772
773
774
775
776 #ifdef ASSERT
777 bool CompilationPolicy::verify_level(CompLevel level) {
778 if (TieredCompilation && level > TieredStopAtLevel) {
779 return false;
780 }
781 // Check if there is a compiler to process the requested level
782 if (!CompilerConfig::is_c1_enabled() && is_c1_compile(level)) {
783 return false;
784 }
785 if (!CompilerConfig::is_c2_or_jvmci_compiler_enabled() && is_c2_compile(level)) {
786 return false;
787 }
788
789 // Interpreter level is always valid.
790 if (level == CompLevel_none) {
791 return true;
792 }
793 if (CompilationModeFlag::normal()) {
794 return true;
795 } else if (CompilationModeFlag::quick_only()) {
796 return level == CompLevel_simple;
797 } else if (CompilationModeFlag::high_only()) {
798 return level == CompLevel_full_optimization;
799 } else if (CompilationModeFlag::high_only_quick_internal()) {
800 return level == CompLevel_full_optimization || level == CompLevel_simple;
801 }
802 return false;
803 }
804 #endif
805
806
807 CompLevel CompilationPolicy::highest_compile_level() {
808 CompLevel level = CompLevel_none;
809 // Setup the maximum level available for the current compiler configuration.
810 if (!CompilerConfig::is_interpreter_only()) {
811 if (CompilerConfig::is_c2_or_jvmci_compiler_enabled()) {
812 level = CompLevel_full_optimization;
813 } else if (CompilerConfig::is_c1_enabled()) {
814 if (CompilerConfig::is_c1_simple_only()) {
815 level = CompLevel_simple;
816 } else {
817 level = CompLevel_full_profile;
818 }
819 }
820 }
821 // Clamp the maximum level with TieredStopAtLevel.
822 if (TieredCompilation) {
823 level = MIN2(level, (CompLevel) TieredStopAtLevel);
824 }
825
826 // Fix it up if after the clamping it has become invalid.
827 // Bring it monotonically down depending on the next available level for
828 // the compilation mode.
829 if (!CompilationModeFlag::normal()) {
830 // a) quick_only - levels 2,3,4 are invalid; levels -1,0,1 are valid;
831 // b) high_only - levels 1,2,3 are invalid; levels -1,0,4 are valid;
832 // c) high_only_quick_internal - levels 2,3 are invalid; levels -1,0,1,4 are valid.
833 if (CompilationModeFlag::quick_only()) {
834 if (level == CompLevel_limited_profile || level == CompLevel_full_profile || level == CompLevel_full_optimization) {
835 level = CompLevel_simple;
836 }
837 } else if (CompilationModeFlag::high_only()) {
838 if (level == CompLevel_simple || level == CompLevel_limited_profile || level == CompLevel_full_profile) {
839 level = CompLevel_none;
840 }
841 } else if (CompilationModeFlag::high_only_quick_internal()) {
842 if (level == CompLevel_limited_profile || level == CompLevel_full_profile) {
843 level = CompLevel_simple;
844 }
845 }
846 }
847
848 assert(verify_level(level), "Invalid highest compilation level: %d", level);
849 return level;
850 }
851
852 CompLevel CompilationPolicy::limit_level(CompLevel level) {
853 level = MIN2(level, highest_compile_level());
854 assert(verify_level(level), "Invalid compilation level: %d", level);
855 return level;
856 }
857
858 CompLevel CompilationPolicy::initial_compile_level(const methodHandle& method) {
859 CompLevel level = CompLevel_any;
860 if (CompilationModeFlag::normal()) {
861 level = CompLevel_full_profile;
862 } else if (CompilationModeFlag::quick_only()) {
863 level = CompLevel_simple;
864 } else if (CompilationModeFlag::high_only()) {
865 level = CompLevel_full_optimization;
866 } else if (CompilationModeFlag::high_only_quick_internal()) {
867 if (force_comp_at_level_simple(method)) {
868 level = CompLevel_simple;
869 } else {
870 level = CompLevel_full_optimization;
871 }
872 }
873 assert(level != CompLevel_any, "Unhandled compilation mode");
874 return limit_level(level);
875 }
876
877 // Set carry flags on the counters if necessary
878 void CompilationPolicy::handle_counter_overflow(const methodHandle& method) {
879 MethodCounters *mcs = method->method_counters();
880 if (mcs != nullptr) {
881 mcs->invocation_counter()->set_carry_on_overflow();
882 mcs->backedge_counter()->set_carry_on_overflow();
883 }
884 MethodData* mdo = method->method_data();
885 if (mdo != nullptr) {
886 mdo->invocation_counter()->set_carry_on_overflow();
887 mdo->backedge_counter()->set_carry_on_overflow();
888 }
889 }
890
891 // Called with the queue locked and with at least one element
892 CompileTask* CompilationPolicy::select_task(CompileQueue* compile_queue, JavaThread* THREAD) {
893 CompileTask *max_blocking_task = nullptr;
894 CompileTask *max_task = nullptr;
895 Method* max_method = nullptr;
896
897 int64_t t = nanos_to_millis(os::javaTimeNanos());
898 // Iterate through the queue and find a method with a maximum rate.
899 for (CompileTask* task = compile_queue->first(); task != nullptr;) {
900 CompileTask* next_task = task->next();
901 // If a method was unloaded or has been stale for some time, remove it from the queue.
902 // Blocking tasks and tasks submitted from whitebox API don't become stale
903 if (task->is_unloaded()) {
904 compile_queue->remove_and_mark_stale(task);
905 task = next_task;
906 continue;
907 }
908 Method* method = task->method();
909 methodHandle mh(THREAD, method);
910 if (task->can_become_stale() && is_stale(t, TieredCompileTaskTimeout, mh) && !is_old(mh)) {
911 if (PrintTieredEvents) {
912 print_event(REMOVE_FROM_QUEUE, method, method, task->osr_bci(), (CompLevel) task->comp_level());
913 }
914 method->clear_queued_for_compilation();
915 method->set_pending_queue_processed(false);
916 compile_queue->remove_and_mark_stale(task);
917 task = next_task;
918 continue;
919 }
920 update_rate(t, mh);
921 if (max_task == nullptr || compare_methods(method, max_method) || compare_tasks(task, max_task)) {
922 // Select a method with the highest rate
923 max_task = task;
924 max_method = method;
925 }
926
927 if (task->is_blocking()) {
928 if (max_blocking_task == nullptr || compare_methods(method, max_blocking_task->method())) {
929 max_blocking_task = task;
930 }
931 }
932
933 task = next_task;
934 }
935
936 if (max_blocking_task != nullptr) {
937 // In blocking compilation mode, the CompileBroker will make
938 // compilations submitted by a JVMCI compiler thread non-blocking. These
939 // compilations should be scheduled after all blocking compilations
940 // to service non-compiler related compilations sooner and reduce the
941 // chance of such compilations timing out.
942 max_task = max_blocking_task;
943 max_method = max_task->method();
944 }
945
946 methodHandle max_method_h(THREAD, max_method);
947
948 if (max_task != nullptr && max_task->comp_level() == CompLevel_full_profile && TieredStopAtLevel > CompLevel_full_profile &&
949 max_method != nullptr && is_method_profiled(max_method_h) && !Arguments::is_compiler_only()) {
950 max_task->set_comp_level(CompLevel_limited_profile);
951
952 if (CompileBroker::compilation_is_complete(max_method_h(), max_task->osr_bci(), CompLevel_limited_profile,
953 false /* requires_online_compilation */,
954 CompileTask::Reason_None)) {
955 if (PrintTieredEvents) {
956 print_event(REMOVE_FROM_QUEUE, max_method, max_method, max_task->osr_bci(), (CompLevel)max_task->comp_level());
957 }
958 compile_queue->remove_and_mark_stale(max_task);
959 max_method->clear_queued_for_compilation();
960 return nullptr;
961 }
962
963 if (PrintTieredEvents) {
964 print_event(UPDATE_IN_QUEUE, max_method, max_method, max_task->osr_bci(), (CompLevel)max_task->comp_level());
965 }
966 }
967 return max_task;
968 }
969
970 void CompilationPolicy::reprofile(ScopeDesc* trap_scope, bool is_osr) {
971 for (ScopeDesc* sd = trap_scope;; sd = sd->sender()) {
972 if (PrintTieredEvents) {
973 print_event(REPROFILE, sd->method(), sd->method(), InvocationEntryBci, CompLevel_none);
974 }
975 MethodData* mdo = sd->method()->method_data();
976 if (mdo != nullptr) {
977 mdo->reset_start_counters();
978 }
979 if (sd->is_top()) break;
980 }
981 }
982
983 nmethod* CompilationPolicy::event(const methodHandle& method, const methodHandle& inlinee,
984 int branch_bci, int bci, CompLevel comp_level, nmethod* nm, TRAPS) {
985 if (PrintTieredEvents) {
986 print_event(bci == InvocationEntryBci ? CALL : LOOP, method(), inlinee(), bci, comp_level);
987 }
988
989 #if INCLUDE_JVMCI
990 if (EnableJVMCI && UseJVMCICompiler &&
991 comp_level == CompLevel_full_optimization && !ClassPreloader::class_preloading_finished()) {
992 return nullptr;
993 }
994 #endif
995
996 if (comp_level == CompLevel_none &&
997 JvmtiExport::can_post_interpreter_events() &&
998 THREAD->is_interp_only_mode()) {
999 return nullptr;
1000 }
1001 if (ReplayCompiles) {
1002 // Don't trigger other compiles in testing mode
1003 return nullptr;
1004 }
1005
1006 handle_counter_overflow(method);
1007 if (method() != inlinee()) {
1008 handle_counter_overflow(inlinee);
1009 }
1010
1011 if (bci == InvocationEntryBci) {
1012 method_invocation_event(method, inlinee, comp_level, nm, THREAD);
1013 } else {
1014 // method == inlinee if the event originated in the main method
1015 method_back_branch_event(method, inlinee, bci, comp_level, nm, THREAD);
1016 // Check if event led to a higher level OSR compilation
1017 CompLevel expected_comp_level = MIN2(CompLevel_full_optimization, static_cast<CompLevel>(comp_level + 1));
1018 if (!CompilationModeFlag::disable_intermediate() && inlinee->is_not_osr_compilable(expected_comp_level)) {
1019 // It's not possible to reach the expected level so fall back to simple.
1020 expected_comp_level = CompLevel_simple;
1021 }
1022 CompLevel max_osr_level = static_cast<CompLevel>(inlinee->highest_osr_comp_level());
1023 if (max_osr_level >= expected_comp_level) { // fast check to avoid locking in a typical scenario
1024 nmethod* osr_nm = inlinee->lookup_osr_nmethod_for(bci, expected_comp_level, false);
1025 assert(osr_nm == nullptr || osr_nm->comp_level() >= expected_comp_level, "lookup_osr_nmethod_for is broken");
1026 if (osr_nm != nullptr && osr_nm->comp_level() != comp_level) {
1027 // Perform OSR with new nmethod
1028 return osr_nm;
1029 }
1030 }
1031 }
1032 return nullptr;
1033 }
1034
1035 // Check if the method can be compiled, change level if necessary
1036 void CompilationPolicy::compile(const methodHandle& mh, int bci, CompLevel level, TRAPS) {
1037 assert(verify_level(level), "Invalid compilation level requested: %d", level);
1038
1039 if (level == CompLevel_none) {
1040 if (mh->has_compiled_code()) {
1041 // Happens when we switch to interpreter to profile.
1042 MutexLocker ml(Compile_lock);
1043 NoSafepointVerifier nsv;
1044 if (mh->has_compiled_code()) {
1045 mh->code()->make_not_used();
1046 }
1047 // Deoptimize immediately (we don't have to wait for a compile).
1048 JavaThread* jt = THREAD;
1049 RegisterMap map(jt,
1050 RegisterMap::UpdateMap::skip,
1051 RegisterMap::ProcessFrames::include,
1052 RegisterMap::WalkContinuation::skip);
1053 frame fr = jt->last_frame().sender(&map);
1054 Deoptimization::deoptimize_frame(jt, fr.id());
1055 }
1056 return;
1057 }
1058
1059 if (!CompilationModeFlag::disable_intermediate()) {
1060 // Check if the method can be compiled. If it cannot be compiled with C1, continue profiling
1061 // in the interpreter and then compile with C2 (the transition function will request that,
1062 // see common() ). If the method cannot be compiled with C2 but still can with C1, compile it with
1063 // pure C1.
1064 if ((bci == InvocationEntryBci && !can_be_compiled(mh, level))) {
1065 if (level == CompLevel_full_optimization && can_be_compiled(mh, CompLevel_simple)) {
1066 compile(mh, bci, CompLevel_simple, THREAD);
1067 }
1068 return;
1069 }
1070 if ((bci != InvocationEntryBci && !can_be_osr_compiled(mh, level))) {
1071 if (level == CompLevel_full_optimization && can_be_osr_compiled(mh, CompLevel_simple)) {
1072 nmethod* osr_nm = mh->lookup_osr_nmethod_for(bci, CompLevel_simple, false);
1073 if (osr_nm != nullptr && osr_nm->comp_level() > CompLevel_simple) {
1074 // Invalidate the existing OSR nmethod so that a compile at CompLevel_simple is permitted.
1075 osr_nm->make_not_entrant();
1076 }
1077 compile(mh, bci, CompLevel_simple, THREAD);
1078 }
1079 return;
1080 }
1081 }
1082 if (bci != InvocationEntryBci && mh->is_not_osr_compilable(level)) {
1083 return;
1084 }
1085 if (!CompileBroker::compilation_is_in_queue(mh)) {
1086 if (PrintTieredEvents) {
1087 print_event(COMPILE, mh(), mh(), bci, level);
1088 }
1089 int hot_count = (bci == InvocationEntryBci) ? mh->invocation_count() : mh->backedge_count();
1090 update_rate(nanos_to_millis(os::javaTimeNanos()), mh);
1091 bool requires_online_compilation = false;
1092 if (TrainingData::have_data()) {
1093 MethodTrainingData* mtd = MethodTrainingData::find(mh);
1094 if (mtd != nullptr) {
1095 CompileTrainingData* ctd = mtd->last_toplevel_compile(level);
1096 if (ctd != nullptr) {
1097 requires_online_compilation = (ctd->init_deps_left() > 0);
1098 }
1099 }
1100 }
1101 CompileBroker::compile_method(mh, bci, level, mh, hot_count, requires_online_compilation, CompileTask::Reason_Tiered, THREAD);
1102 }
1103 }
1104
1105 // update_rate() is called from select_task() while holding a compile queue lock.
1106 void CompilationPolicy::update_rate(int64_t t, const methodHandle& method) {
1107 // Skip update if counters are absent.
1108 // Can't allocate them since we are holding compile queue lock.
1109 if (method->method_counters() == nullptr) return;
1110
1111 if (is_old(method)) {
1112 // We don't remove old methods from the queue,
1113 // so we can just zero the rate.
1114 method->set_rate(0);
1115 return;
1116 }
1117
1118 // We don't update the rate if we've just came out of a safepoint.
1119 // delta_s is the time since last safepoint in milliseconds.
1120 int64_t delta_s = t - SafepointTracing::end_of_last_safepoint_ms();
1121 int64_t delta_t = t - (method->prev_time() != 0 ? method->prev_time() : start_time()); // milliseconds since the last measurement
1122 // How many events were there since the last time?
1123 int event_count = method->invocation_count() + method->backedge_count();
1124 int delta_e = event_count - method->prev_event_count();
1125
1126 // We should be running for at least 1ms.
1127 if (delta_s >= TieredRateUpdateMinTime) {
1128 // And we must've taken the previous point at least 1ms before.
1129 if (delta_t >= TieredRateUpdateMinTime && delta_e > 0) {
1130 method->set_prev_time(t);
1131 method->set_prev_event_count(event_count);
1132 method->set_rate((float)delta_e / (float)delta_t); // Rate is events per millisecond
1133 } else {
1134 if (delta_t > TieredRateUpdateMaxTime && delta_e == 0) {
1135 // If nothing happened for 25ms, zero the rate. Don't modify prev values.
1136 method->set_rate(0);
1137 }
1138 }
1139 }
1140 }
1141
1142 // Check if this method has been stale for a given number of milliseconds.
1143 // See select_task().
1144 bool CompilationPolicy::is_stale(int64_t t, int64_t timeout, const methodHandle& method) {
1145 int64_t delta_s = t - SafepointTracing::end_of_last_safepoint_ms();
1146 int64_t delta_t = t - method->prev_time();
1147 if (delta_t > timeout && delta_s > timeout) {
1148 int event_count = method->invocation_count() + method->backedge_count();
1149 int delta_e = event_count - method->prev_event_count();
1150 // Return true if there were no events.
1151 return delta_e == 0;
1152 }
1153 return false;
1154 }
1155
1156 // We don't remove old methods from the compile queue even if they have
1157 // very low activity. See select_task().
1158 bool CompilationPolicy::is_old(const methodHandle& method) {
1159 int i = method->invocation_count();
1160 int b = method->backedge_count();
1161 double k = TieredOldPercentage / 100.0;
1162
1163 return CallPredicate::apply_scaled(method, CompLevel_none, i, b, k) || LoopPredicate::apply_scaled(method, CompLevel_none, i, b, k);
1164 }
1165
1166 double CompilationPolicy::weight(Method* method) {
1167 return (double)(method->rate() + 1) * (method->invocation_count() + 1) * (method->backedge_count() + 1);
1168 }
1169
1170 // Apply heuristics and return true if x should be compiled before y
1171 bool CompilationPolicy::compare_methods(Method* x, Method* y) {
1172 if (x->highest_comp_level() > y->highest_comp_level()) {
1173 // recompilation after deopt
1174 return true;
1175 } else
1176 if (x->highest_comp_level() == y->highest_comp_level()) {
1177 if (weight(x) > weight(y)) {
1178 return true;
1179 }
1180 }
1181 return false;
1182 }
1183
1184 bool CompilationPolicy::compare_tasks(CompileTask* x, CompileTask* y) {
1185 if (x->is_scc() && !y->is_scc()) {
1186 // x has cached code
1187 return true;
1188 }
1189 if (x->compile_reason() != y->compile_reason() && y->compile_reason() == CompileTask::Reason_MustBeCompiled) {
1190 return true;
1191 }
1192 return false;
1193 }
1194
1195 // Is method profiled enough?
1196 bool CompilationPolicy::is_method_profiled(const methodHandle& method) {
1197 MethodData* mdo = method->method_data();
1198 if (mdo != nullptr) {
1199 int i = mdo->invocation_count_delta();
1200 int b = mdo->backedge_count_delta();
1201 return CallPredicate::apply_scaled(method, CompLevel_full_profile, i, b, 1);
1202 }
1203 return false;
1204 }
1205
1206
1207 // Determine is a method is mature.
1208 bool CompilationPolicy::is_mature(MethodData* mdo) {
1209 if (Arguments::is_compiler_only()) {
1210 // Always report profiles as immature with -Xcomp
1211 return false;
1212 }
1213 methodHandle mh(Thread::current(), mdo->method());
1214 if (mdo != nullptr) {
1215 int i = mdo->invocation_count();
1216 int b = mdo->backedge_count();
1217 double k = ProfileMaturityPercentage / 100.0;
1218 return CallPredicate::apply_scaled(mh, CompLevel_full_profile, i, b, k) || LoopPredicate::apply_scaled(mh, CompLevel_full_profile, i, b, k);
1219 }
1220 return false;
1221 }
1222
1223 // If a method is old enough and is still in the interpreter we would want to
1224 // start profiling without waiting for the compiled method to arrive.
1225 // We also take the load on compilers into the account.
1226 bool CompilationPolicy::should_create_mdo(const methodHandle& method, CompLevel cur_level) {
1227 if (cur_level != CompLevel_none || force_comp_at_level_simple(method) || CompilationModeFlag::quick_only() || !ProfileInterpreter) {
1228 return false;
1229 }
1230
1231 if (TrainingData::have_data()) {
1232 MethodTrainingData* mtd = MethodTrainingData::find(method);
1233 if (mtd != nullptr && mtd->saw_level(CompLevel_full_optimization)) {
1234 return true;
1235 }
1236 return false;
1237 }
1238
1239 if (is_old(method)) {
1240 return true;
1241 }
1242
1243 int i = method->invocation_count();
1244 int b = method->backedge_count();
1245 double k = Tier0ProfilingStartPercentage / 100.0;
1246
1247 // If the top level compiler is not keeping up, delay profiling.
1248 if (CompileBroker::queue_size(CompLevel_full_optimization) <= Tier0Delay * compiler_count(CompLevel_full_optimization)) {
1249 return CallPredicate::apply_scaled(method, CompLevel_none, i, b, k) || LoopPredicate::apply_scaled(method, CompLevel_none, i, b, k);
1250 }
1251 return false;
1252 }
1253
1254 // Inlining control: if we're compiling a profiled method with C1 and the callee
1255 // is known to have OSRed in a C2 version, don't inline it.
1256 bool CompilationPolicy::should_not_inline(ciEnv* env, ciMethod* callee) {
1257 CompLevel comp_level = (CompLevel)env->comp_level();
1258 if (comp_level == CompLevel_full_profile ||
1259 comp_level == CompLevel_limited_profile) {
1260 return callee->highest_osr_comp_level() == CompLevel_full_optimization;
1261 }
1262 return false;
1263 }
1264
1265 // Create MDO if necessary.
1266 void CompilationPolicy::create_mdo(const methodHandle& mh, JavaThread* THREAD) {
1267 if (mh->is_native() ||
1268 mh->is_abstract() ||
1269 mh->is_accessor() ||
1270 mh->is_constant_getter()) {
1271 return;
1272 }
1273 if (mh->method_data() == nullptr) {
1274 Method::build_profiling_method_data(mh, CHECK_AND_CLEAR);
1275 }
1276 if (ProfileInterpreter && THREAD->has_last_Java_frame()) {
1277 MethodData* mdo = mh->method_data();
1278 if (mdo != nullptr) {
1279 frame last_frame = THREAD->last_frame();
1280 if (last_frame.is_interpreted_frame() && mh == last_frame.interpreter_frame_method()) {
1281 int bci = last_frame.interpreter_frame_bci();
1282 address dp = mdo->bci_to_dp(bci);
1283 last_frame.interpreter_frame_set_mdp(dp);
1284 }
1285 }
1286 }
1287 }
1288
1289 CompLevel CompilationPolicy::trained_transition_from_none(const methodHandle& method, CompLevel cur_level, MethodTrainingData* mtd, JavaThread* THREAD) {
1290 precond(mtd != nullptr);
1291 precond(cur_level == CompLevel_none);
1292
1293 if (mtd->only_inlined() && !mtd->saw_level(CompLevel_full_optimization)) {
1294 return CompLevel_none;
1295 }
1296
1297 bool training_has_profile = (mtd->final_profile() != nullptr);
1298 if (mtd->saw_level(CompLevel_full_optimization) && !training_has_profile) {
1299 return CompLevel_full_profile;
1300 }
1301
1302 CompLevel highest_training_level = static_cast<CompLevel>(mtd->highest_top_level());
1303 switch (highest_training_level) {
1304 case CompLevel_limited_profile:
1305 case CompLevel_full_profile:
1306 return CompLevel_limited_profile;
1307 case CompLevel_simple:
1308 return CompLevel_simple;
1309 case CompLevel_none:
1310 return CompLevel_none;
1311 default:
1312 break;
1313 }
1314
1315 // Now handle the case of level 4.
1316 assert(highest_training_level == CompLevel_full_optimization, "Unexpected compilation level: %d", highest_training_level);
1317 if (!training_has_profile) {
1318 // The method was a part of a level 4 compile, but don't have a stored profile,
1319 // we need to profile it.
1320 return CompLevel_full_profile;
1321 }
1322 const bool deopt = (static_cast<CompLevel>(method->highest_comp_level()) == CompLevel_full_optimization);
1323 // If we deopted, then we reprofile
1324 if (deopt && !is_method_profiled(method)) {
1325 return CompLevel_full_profile;
1326 }
1327
1328 CompileTrainingData* ctd = mtd->last_toplevel_compile(CompLevel_full_optimization);
1329 assert(ctd != nullptr, "Should have CTD for CompLevel_full_optimization");
1330 // With SkipTier2IfPossible and all deps satisfied, go to level 4 immediately
1331 if (SkipTier2IfPossible && ctd->init_deps_left() == 0) {
1332 if (method->method_data() == nullptr) {
1333 create_mdo(method, THREAD);
1334 }
1335 return CompLevel_full_optimization;
1336 }
1337
1338 // Otherwise go to level 2
1339 return CompLevel_limited_profile;
1340 }
1341
1342
1343 CompLevel CompilationPolicy::trained_transition_from_limited_profile(const methodHandle& method, CompLevel cur_level, MethodTrainingData* mtd, JavaThread* THREAD) {
1344 precond(mtd != nullptr);
1345 precond(cur_level == CompLevel_limited_profile);
1346
1347 // One of the main reasons that we can get here is that we're waiting for the stored C2 code to become ready.
1348
1349 // But first, check if we have a saved profile
1350 bool training_has_profile = (mtd->final_profile() != nullptr);
1351 if (!training_has_profile) {
1352 return CompLevel_full_profile;
1353 }
1354
1355
1356 assert(training_has_profile, "Have to have a profile to be here");
1357 // Check if the method is ready
1358 CompileTrainingData* ctd = mtd->last_toplevel_compile(CompLevel_full_optimization);
1359 if (ctd != nullptr && ctd->init_deps_left() == 0) {
1360 if (method->method_data() == nullptr) {
1361 create_mdo(method, THREAD);
1362 }
1363 return CompLevel_full_optimization;
1364 }
1365
1366 // Otherwise stay at the current level
1367 return CompLevel_limited_profile;
1368 }
1369
1370
1371 CompLevel CompilationPolicy::trained_transition_from_full_profile(const methodHandle& method, CompLevel cur_level, MethodTrainingData* mtd, JavaThread* THREAD) {
1372 precond(mtd != nullptr);
1373 precond(cur_level == CompLevel_full_profile);
1374
1375 CompLevel highest_training_level = static_cast<CompLevel>(mtd->highest_top_level());
1376 // We have method at the full profile level and we also know that it's possibly an important method.
1377 if (highest_training_level == CompLevel_full_optimization && !mtd->only_inlined()) {
1378 // Check if it is adequately profiled
1379 if (is_method_profiled(method)) {
1380 return CompLevel_full_optimization;
1381 }
1382 }
1383
1384 // Otherwise stay at the current level
1385 return CompLevel_full_profile;
1386 }
1387
1388 CompLevel CompilationPolicy::trained_transition(const methodHandle& method, CompLevel cur_level, MethodTrainingData* mtd, JavaThread* THREAD) {
1389 precond(MethodTrainingData::have_data());
1390
1391 // If there is no training data recorded for this method, bail out.
1392 if (mtd == nullptr) {
1393 return cur_level;
1394 }
1395
1396 CompLevel next_level = cur_level;
1397 switch(cur_level) {
1398 default: break;
1399 case CompLevel_none:
1400 next_level = trained_transition_from_none(method, cur_level, mtd, THREAD);
1401 break;
1402 case CompLevel_limited_profile:
1403 next_level = trained_transition_from_limited_profile(method, cur_level, mtd, THREAD);
1404 break;
1405 case CompLevel_full_profile:
1406 next_level = trained_transition_from_full_profile(method, cur_level, mtd, THREAD);
1407 break;
1408 }
1409
1410 // We don't have any special strategies for the C2-only compilation modes, so just fix up the levels for now.
1411 if (CompilationModeFlag::high_only_quick_internal() && CompLevel_simple < next_level && next_level < CompLevel_full_optimization) {
1412 return CompLevel_none;
1413 }
1414 if (CompilationModeFlag::high_only() && next_level < CompLevel_full_optimization) {
1415 return CompLevel_none;
1416 }
1417 return next_level;
1418 }
1419
1420 /*
1421 * Method states:
1422 * 0 - interpreter (CompLevel_none)
1423 * 1 - pure C1 (CompLevel_simple)
1424 * 2 - C1 with invocation and backedge counting (CompLevel_limited_profile)
1425 * 3 - C1 with full profiling (CompLevel_full_profile)
1426 * 4 - C2 or Graal (CompLevel_full_optimization)
1427 *
1428 * Common state transition patterns:
1429 * a. 0 -> 3 -> 4.
1430 * The most common path. But note that even in this straightforward case
1431 * profiling can start at level 0 and finish at level 3.
1432 *
1433 * b. 0 -> 2 -> 3 -> 4.
1434 * This case occurs when the load on C2 is deemed too high. So, instead of transitioning
1435 * into state 3 directly and over-profiling while a method is in the C2 queue we transition to
1436 * level 2 and wait until the load on C2 decreases. This path is disabled for OSRs.
1437 *
1438 * c. 0 -> (3->2) -> 4.
1439 * In this case we enqueue a method for compilation at level 3, but the C1 queue is long enough
1440 * to enable the profiling to fully occur at level 0. In this case we change the compilation level
1441 * of the method to 2 while the request is still in-queue, because it'll allow it to run much faster
1442 * without full profiling while c2 is compiling.
1443 *
1444 * d. 0 -> 3 -> 1 or 0 -> 2 -> 1.
1445 * After a method was once compiled with C1 it can be identified as trivial and be compiled to
1446 * level 1. These transition can also occur if a method can't be compiled with C2 but can with C1.
1447 *
1448 * e. 0 -> 4.
1449 * This can happen if a method fails C1 compilation (it will still be profiled in the interpreter)
1450 * or because of a deopt that didn't require reprofiling (compilation won't happen in this case because
1451 * the compiled version already exists).
1452 *
1453 * Note that since state 0 can be reached from any other state via deoptimization different loops
1454 * are possible.
1455 *
1456 */
1457
1458 // Common transition function. Given a predicate determines if a method should transition to another level.
1459 template<typename Predicate>
1460 CompLevel CompilationPolicy::common(const methodHandle& method, CompLevel cur_level, JavaThread* THREAD, bool disable_feedback) {
1461 CompLevel next_level = cur_level;
1462 int i = method->invocation_count();
1463 int b = method->backedge_count();
1464
1465 if (force_comp_at_level_simple(method)) {
1466 next_level = CompLevel_simple;
1467 } else {
1468 if (MethodTrainingData::have_data()) {
1469 MethodTrainingData* mtd = MethodTrainingData::find(method);
1470 if (mtd == nullptr) {
1471 // We haven't see compilations of this method in training. It's either very cold or the behavior changed.
1472 // Feed it to the standard TF with no profiling delay.
1473 next_level = standard_transition<Predicate>(method, cur_level, false /*delay_profiling*/, disable_feedback);
1474 } else {
1475 next_level = trained_transition(method, cur_level, mtd, THREAD);
1476 if (cur_level == next_level) {
1477 // trained_transtion() is going to return the same level if no startup/warmup optimizations apply.
1478 // In order to catch possible pathologies due to behavior change we feed the event to the regular
1479 // TF but with profiling delay.
1480 next_level = standard_transition<Predicate>(method, cur_level, true /*delay_profiling*/, disable_feedback);
1481 }
1482 }
1483 } else if (is_trivial(method) || method->is_native()) {
1484 next_level = CompilationModeFlag::disable_intermediate() ? CompLevel_full_optimization : CompLevel_simple;
1485 } else {
1486 next_level = standard_transition<Predicate>(method, cur_level, false /*delay_profiling*/, disable_feedback);
1487 }
1488 }
1489 return (next_level != cur_level) ? limit_level(next_level) : next_level;
1490 }
1491
1492
1493 template<typename Predicate>
1494 CompLevel CompilationPolicy::standard_transition(const methodHandle& method, CompLevel cur_level, bool delay_profiling, bool disable_feedback) {
1495 CompLevel next_level = cur_level;
1496 switch(cur_level) {
1497 default: break;
1498 case CompLevel_none:
1499 next_level = transition_from_none<Predicate>(method, cur_level, delay_profiling, disable_feedback);
1500 break;
1501 case CompLevel_limited_profile:
1502 next_level = transition_from_limited_profile<Predicate>(method, cur_level, delay_profiling, disable_feedback);
1503 break;
1504 case CompLevel_full_profile:
1505 next_level = transition_from_full_profile<Predicate>(method, cur_level);
1506 break;
1507 }
1508 return next_level;
1509 }
1510
1511 template<typename Predicate>
1512 CompLevel CompilationPolicy::transition_from_none(const methodHandle& method, CompLevel cur_level, bool delay_profiling, bool disable_feedback) {
1513 precond(cur_level == CompLevel_none);
1514 CompLevel next_level = cur_level;
1515 int i = method->invocation_count();
1516 int b = method->backedge_count();
1517 double scale = delay_profiling ? Tier0ProfileDelayFactor : 1.0;
1518 // If we were at full profile level, would we switch to full opt?
1519 if (transition_from_full_profile<Predicate>(method, CompLevel_full_profile) == CompLevel_full_optimization) {
1520 next_level = CompLevel_full_optimization;
1521 } else if (!CompilationModeFlag::disable_intermediate() && Predicate::apply_scaled(method, cur_level, i, b, scale)) {
1522 // C1-generated fully profiled code is about 30% slower than the limited profile
1523 // code that has only invocation and backedge counters. The observation is that
1524 // if C2 queue is large enough we can spend too much time in the fully profiled code
1525 // while waiting for C2 to pick the method from the queue. To alleviate this problem
1526 // we introduce a feedback on the C2 queue size. If the C2 queue is sufficiently long
1527 // we choose to compile a limited profiled version and then recompile with full profiling
1528 // when the load on C2 goes down.
1529 if (delay_profiling || (!disable_feedback && CompileBroker::queue_size(CompLevel_full_optimization) > Tier3DelayOn * compiler_count(CompLevel_full_optimization))) {
1530 next_level = CompLevel_limited_profile;
1531 } else {
1532 next_level = CompLevel_full_profile;
1533 }
1534 }
1535 return next_level;
1536 }
1537
1538 template<typename Predicate>
1539 CompLevel CompilationPolicy::transition_from_full_profile(const methodHandle& method, CompLevel cur_level) {
1540 precond(cur_level == CompLevel_full_profile);
1541 CompLevel next_level = cur_level;
1542 MethodData* mdo = method->method_data();
1543 if (mdo != nullptr) {
1544 if (mdo->would_profile() || CompilationModeFlag::disable_intermediate()) {
1545 int mdo_i = mdo->invocation_count_delta();
1546 int mdo_b = mdo->backedge_count_delta();
1547 if (Predicate::apply(method, cur_level, mdo_i, mdo_b)) {
1548 next_level = CompLevel_full_optimization;
1549 }
1550 } else {
1551 next_level = CompLevel_full_optimization;
1552 }
1553 }
1554 return next_level;
1555 }
1556
1557 template<typename Predicate>
1558 CompLevel CompilationPolicy::transition_from_limited_profile(const methodHandle& method, CompLevel cur_level, bool delay_profiling, bool disable_feedback) {
1559 precond(cur_level == CompLevel_limited_profile);
1560 CompLevel next_level = cur_level;
1561 int i = method->invocation_count();
1562 int b = method->backedge_count();
1563 double scale = delay_profiling ? Tier2ProfileDelayFactor : 1.0;
1564 MethodData* mdo = method->method_data();
1565 if (mdo != nullptr) {
1566 if (mdo->would_profile()) {
1567 if (disable_feedback || (CompileBroker::queue_size(CompLevel_full_optimization) <=
1568 Tier3DelayOff * compiler_count(CompLevel_full_optimization) &&
1569 Predicate::apply_scaled(method, cur_level, i, b, scale))) {
1570 next_level = CompLevel_full_profile;
1571 }
1572 } else {
1573 next_level = CompLevel_full_optimization;
1574 }
1575 } else {
1576 // If there is no MDO we need to profile
1577 if (disable_feedback || (CompileBroker::queue_size(CompLevel_full_optimization) <=
1578 Tier3DelayOff * compiler_count(CompLevel_full_optimization) &&
1579 Predicate::apply_scaled(method, cur_level, i, b, scale))) {
1580 next_level = CompLevel_full_profile;
1581 }
1582 }
1583 if (next_level == CompLevel_full_profile && is_method_profiled(method)) {
1584 next_level = CompLevel_full_optimization;
1585 }
1586 return next_level;
1587 }
1588
1589
1590 // Determine if a method should be compiled with a normal entry point at a different level.
1591 CompLevel CompilationPolicy::call_event(const methodHandle& method, CompLevel cur_level, JavaThread* THREAD) {
1592 CompLevel osr_level = MIN2((CompLevel) method->highest_osr_comp_level(), common<LoopPredicate>(method, cur_level, THREAD, true));
1593 CompLevel next_level = common<CallPredicate>(method, cur_level, THREAD, !TrainingData::have_data() && is_old(method));
1594
1595 // If OSR method level is greater than the regular method level, the levels should be
1596 // equalized by raising the regular method level in order to avoid OSRs during each
1597 // invocation of the method.
1598 if (osr_level == CompLevel_full_optimization && cur_level == CompLevel_full_profile) {
1599 MethodData* mdo = method->method_data();
1600 guarantee(mdo != nullptr, "MDO should not be nullptr");
1601 if (mdo->invocation_count() >= 1) {
1602 next_level = CompLevel_full_optimization;
1603 }
1604 } else {
1605 next_level = MAX2(osr_level, next_level);
1606 }
1607 #if INCLUDE_JVMCI
1608 if (EnableJVMCI && UseJVMCICompiler &&
1609 next_level == CompLevel_full_optimization && !ClassPreloader::class_preloading_finished()) {
1610 next_level = cur_level;
1611 }
1612 #endif
1613 return next_level;
1614 }
1615
1616 // Determine if we should do an OSR compilation of a given method.
1617 CompLevel CompilationPolicy::loop_event(const methodHandle& method, CompLevel cur_level, JavaThread* THREAD) {
1618 CompLevel next_level = common<LoopPredicate>(method, cur_level, THREAD, true);
1619 if (cur_level == CompLevel_none) {
1620 // If there is a live OSR method that means that we deopted to the interpreter
1621 // for the transition.
1622 CompLevel osr_level = MIN2((CompLevel)method->highest_osr_comp_level(), next_level);
1623 if (osr_level > CompLevel_none) {
1624 return osr_level;
1625 }
1626 }
1627 return next_level;
1628 }
1629
1630 // Handle the invocation event.
1631 void CompilationPolicy::method_invocation_event(const methodHandle& mh, const methodHandle& imh,
1632 CompLevel level, nmethod* nm, TRAPS) {
1633 if (should_create_mdo(mh, level)) {
1634 create_mdo(mh, THREAD);
1635 }
1636 CompLevel next_level = call_event(mh, level, THREAD);
1637 if (next_level != level) {
1638 if (is_compilation_enabled() && !CompileBroker::compilation_is_in_queue(mh)) {
1639 compile(mh, InvocationEntryBci, next_level, THREAD);
1640 }
1641 }
1642 }
1643
1644 // Handle the back branch event. Notice that we can compile the method
1645 // with a regular entry from here.
1646 void CompilationPolicy::method_back_branch_event(const methodHandle& mh, const methodHandle& imh,
1647 int bci, CompLevel level, nmethod* nm, TRAPS) {
1648 if (should_create_mdo(mh, level)) {
1649 create_mdo(mh, THREAD);
1650 }
1651 // Check if MDO should be created for the inlined method
1652 if (should_create_mdo(imh, level)) {
1653 create_mdo(imh, THREAD);
1654 }
1655
1656 if (is_compilation_enabled()) {
1657 CompLevel next_osr_level = loop_event(imh, level, THREAD);
1658 CompLevel max_osr_level = (CompLevel)imh->highest_osr_comp_level();
1659 // At the very least compile the OSR version
1660 if (!CompileBroker::compilation_is_in_queue(imh) && (next_osr_level != level)) {
1661 compile(imh, bci, next_osr_level, CHECK);
1662 }
1663
1664 // Use loop event as an opportunity to also check if there's been
1665 // enough calls.
1666 CompLevel cur_level, next_level;
1667 if (mh() != imh()) { // If there is an enclosing method
1668 {
1669 guarantee(nm != nullptr, "Should have nmethod here");
1670 cur_level = comp_level(mh());
1671 next_level = call_event(mh, cur_level, THREAD);
1672
1673 if (max_osr_level == CompLevel_full_optimization) {
1674 // The inlinee OSRed to full opt, we need to modify the enclosing method to avoid deopts
1675 bool make_not_entrant = false;
1676 if (nm->is_osr_method()) {
1677 // This is an osr method, just make it not entrant and recompile later if needed
1678 make_not_entrant = true;
1679 } else {
1680 if (next_level != CompLevel_full_optimization) {
1681 // next_level is not full opt, so we need to recompile the
1682 // enclosing method without the inlinee
1683 cur_level = CompLevel_none;
1684 make_not_entrant = true;
1685 }
1686 }
1687 if (make_not_entrant) {
1688 if (PrintTieredEvents) {
1689 int osr_bci = nm->is_osr_method() ? nm->osr_entry_bci() : InvocationEntryBci;
1690 print_event(MAKE_NOT_ENTRANT, mh(), mh(), osr_bci, level);
1691 }
1692 nm->make_not_entrant();
1693 }
1694 }
1695 // Fix up next_level if necessary to avoid deopts
1696 if (next_level == CompLevel_limited_profile && max_osr_level == CompLevel_full_profile) {
1697 next_level = CompLevel_full_profile;
1698 }
1699 if (cur_level != next_level) {
1700 if (!CompileBroker::compilation_is_in_queue(mh)) {
1701 compile(mh, InvocationEntryBci, next_level, THREAD);
1702 }
1703 }
1704 }
1705 } else {
1706 cur_level = comp_level(mh());
1707 next_level = call_event(mh, cur_level, THREAD);
1708 if (next_level != cur_level) {
1709 if (!CompileBroker::compilation_is_in_queue(mh)) {
1710 compile(mh, InvocationEntryBci, next_level, THREAD);
1711 }
1712 }
1713 }
1714 }
1715 }
1716