1 /*
2 * Copyright (c) 2010, 2025, 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 "cds/aotLinkedClassBulkLoader.hpp"
26 #include "code/aotCodeCache.hpp"
27 #include "code/scopeDesc.hpp"
28 #include "compiler/compilationPolicy.hpp"
29 #include "compiler/compileBroker.hpp"
30 #include "compiler/compilerDefinitions.inline.hpp"
31 #include "compiler/compilerOracle.hpp"
32 #include "compiler/recompilationPolicy.hpp"
33 #include "memory/resourceArea.hpp"
34 #include "oops/method.inline.hpp"
35 #include "oops/methodData.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::_ac_count = 0;
61 double CompilationPolicy::_increase_threshold_at_ratio = 0;
62
63 CompilationPolicy::TrainingReplayQueue CompilationPolicy::_training_replay_queue;
64
65 void compilationPolicy_init() {
66 CompilationPolicy::initialize();
67 }
68
69 int CompilationPolicy::compiler_count(CompLevel comp_level) {
70 if (is_c1_compile(comp_level)) {
71 return c1_count();
72 } else if (is_c2_compile(comp_level)) {
73 return c2_count();
74 }
75 return 0;
76 }
77
78 // Returns true if m must be compiled before executing it
79 // This is intended to force compiles for methods (usually for
80 // debugging) that would otherwise be interpreted for some reason.
81 bool CompilationPolicy::must_be_compiled(const methodHandle& m, int comp_level) {
82 // Don't allow Xcomp to cause compiles in replay mode
83 if (ReplayCompiles) return false;
84
85 if (m->has_compiled_code()) return false; // already compiled
86 if (!can_be_compiled(m, comp_level)) return false;
87
88 return !UseInterpreter || // must compile all methods
89 (AlwaysCompileLoopMethods && m->has_loops() && CompileBroker::should_compile_new_jobs()); // eagerly compile loop methods
90 }
91
92 void CompilationPolicy::maybe_compile_early(const methodHandle& m, MethodTrainingData* mtd, TRAPS) {
93 if (m->method_holder()->is_not_initialized()) {
94 // 'is_not_initialized' means not only '!is_initialized', but also that
95 // initialization has not been started yet ('!being_initialized')
96 // Do not force compilation of methods in uninitialized classes.
97 return;
98 }
99 // Consider replacing conservatively compiled AOT Preload code with faster AOT code
100 nmethod* nm = m->code();
101 bool recompile = (nm != nullptr) && nm->preloaded();
102 CompLevel cur_level = static_cast<CompLevel>(m->highest_comp_level());
103 CompLevel next_level = trained_transition(m, cur_level, mtd, THREAD);
104 if ((next_level != cur_level || recompile) && can_be_compiled(m, next_level) && !CompileBroker::compilation_is_in_queue(m)) {
105 // We are here becasue some of CTD have all init deps satisifed.
106 CompileTrainingData* ctd = mtd->compile_data_for_aot_code(next_level);
107 bool requires_online_compilation = true;
108 if (ctd != nullptr) {
109 // Can't load normal AOT code - not all dependancies are ready,
110 // request normal compilation
111 requires_online_compilation = (ctd->init_deps_left_acquire() > 0);
112 }
113 // Skip compilation if next_level doesn't have CDT or CDT
114 // does not have all class init dependencies satisfied.
115 if (requires_online_compilation) {
116 return;
117 }
118 if (PrintTieredEvents) {
119 print_event(FORCE_COMPILE, m(), m(), InvocationEntryBci, next_level);
120 }
121 CompileBroker::compile_method(m, InvocationEntryBci, next_level, 0, requires_online_compilation, CompileTask::Reason_MustBeCompiled, THREAD);
122 if (HAS_PENDING_EXCEPTION) {
123 CLEAR_PENDING_EXCEPTION;
124 }
125 }
126 }
127
128 void CompilationPolicy::compile_if_required(const methodHandle& m, TRAPS) {
129 if (!THREAD->can_call_java() || THREAD->is_Compiler_thread()) {
130 // don't force compilation, resolve was on behalf of compiler
131 return;
132 }
133 if (m->method_holder()->is_not_initialized()) {
134 // 'is_not_initialized' means not only '!is_initialized', but also that
135 // initialization has not been started yet ('!being_initialized')
136 // Do not force compilation of methods in uninitialized classes.
137 // Note that doing this would throw an assert later,
138 // in CompileBroker::compile_method.
139 // We sometimes use the link resolver to do reflective lookups
140 // even before classes are initialized.
141 return;
142 }
143
144 if (must_be_compiled(m)) {
145 // This path is unusual, mostly used by the '-Xcomp' stress test mode.
146 CompLevel level = initial_compile_level(m);
147 if (PrintTieredEvents) {
148 print_event(FORCE_COMPILE, m(), m(), InvocationEntryBci, level);
149 }
150 // Test AOT code too
151 bool requires_online_compilation = true;
152 if (TrainingData::have_data()) {
153 MethodTrainingData* mtd = MethodTrainingData::find_fast(m);
154 if (mtd != nullptr) {
155 CompileTrainingData* ctd = mtd->last_toplevel_compile(level);
156 if (ctd != nullptr) {
157 requires_online_compilation = (ctd->init_deps_left_acquire() > 0);
158 }
159 }
160 }
161 CompileBroker::compile_method(m, InvocationEntryBci, level, 0, requires_online_compilation, CompileTask::Reason_MustBeCompiled, THREAD);
162 }
163 }
164
165 void CompilationPolicy::replay_training_at_init_impl(InstanceKlass* klass, JavaThread* current) {
166 if (!klass->has_init_deps_processed()) {
167 ResourceMark rm;
168 log_debug(training)("Replay training: %s", klass->external_name());
169
170 KlassTrainingData* ktd = KlassTrainingData::find(klass);
171 if (ktd != nullptr) {
172 guarantee(ktd->has_holder(), "");
173 ktd->notice_fully_initialized(); // sets klass->has_init_deps_processed bit
174 assert(klass->has_init_deps_processed(), "");
175
176 if (AOTCompileEagerly) {
177 GrowableArray<MethodTrainingData*> mtds;
178 ktd->iterate_comp_deps([&](CompileTrainingData* ctd) {
179 if (ctd->init_deps_left_acquire() == 0) {
180 MethodTrainingData* mtd = ctd->method();
181 if (mtd->has_holder()) {
182 mtds.push(mtd);
183 }
184 }
185 });
186 for (int i = 0; i < mtds.length(); i++) {
187 MethodTrainingData* mtd = mtds.at(i);
188 const methodHandle mh(current, const_cast<Method*>(mtd->holder()));
189 CompilationPolicy::maybe_compile_early(mh, mtd, current);
190 }
191 }
192 }
193 }
194 }
195
196 void CompilationPolicy::replay_training_at_init(InstanceKlass* klass, JavaThread* current) {
197 assert(klass->is_initialized(), "");
198 if (TrainingData::have_data() && klass->in_aot_cache()) {
199 _training_replay_queue.push(klass, TrainingReplayQueue_lock, current);
200 }
201 }
202
203 // For TrainingReplayQueue
204 template<>
205 void CompilationPolicyUtils::Queue<InstanceKlass>::print_on(outputStream* st) {
206 int pos = 0;
207 for (QueueNode* cur = _head; cur != nullptr; cur = cur->next()) {
208 ResourceMark rm;
209 InstanceKlass* ik = cur->value();
210 st->print_cr("%3d: " INTPTR_FORMAT " %s", ++pos, p2i(ik), ik->external_name());
211 }
212 }
213
214 void CompilationPolicy::replay_training_at_init_loop(JavaThread* current) {
215 while (!CompileBroker::is_compilation_disabled_forever()) {
216 InstanceKlass* ik = _training_replay_queue.pop(TrainingReplayQueue_lock, current);
217 if (ik != nullptr) {
218 replay_training_at_init_impl(ik, current);
219 }
220 }
221 }
222
223 static inline CompLevel adjust_level_for_compilability_query(CompLevel comp_level) {
224 if (comp_level == CompLevel_any) {
225 if (CompilerConfig::is_c1_only()) {
226 comp_level = CompLevel_simple;
227 } else if (CompilerConfig::is_c2_or_jvmci_compiler_only()) {
228 comp_level = CompLevel_full_optimization;
229 }
230 }
231 return comp_level;
232 }
233
234 // Returns true if m is allowed to be compiled
235 bool CompilationPolicy::can_be_compiled(const methodHandle& m, int comp_level) {
236 // allow any levels for WhiteBox
237 assert(WhiteBoxAPI || comp_level == CompLevel_any || is_compile(comp_level), "illegal compilation level %d", comp_level);
238
239 if (m->is_abstract()) return false;
240 if (DontCompileHugeMethods && m->code_size() > HugeMethodLimit) return false;
241
242 // Math intrinsics should never be compiled as this can lead to
243 // monotonicity problems because the interpreter will prefer the
244 // compiled code to the intrinsic version. This can't happen in
245 // production because the invocation counter can't be incremented
246 // but we shouldn't expose the system to this problem in testing
247 // modes.
248 if (!AbstractInterpreter::can_be_compiled(m)) {
249 return false;
250 }
251 comp_level = adjust_level_for_compilability_query((CompLevel) comp_level);
252 if (comp_level == CompLevel_any || is_compile(comp_level)) {
253 return !m->is_not_compilable(comp_level);
254 }
255 return false;
256 }
257
258 // Returns true if m is allowed to be osr compiled
259 bool CompilationPolicy::can_be_osr_compiled(const methodHandle& m, int comp_level) {
260 bool result = false;
261 comp_level = adjust_level_for_compilability_query((CompLevel) comp_level);
262 if (comp_level == CompLevel_any || is_compile(comp_level)) {
263 result = !m->is_not_osr_compilable(comp_level);
264 }
265 return (result && can_be_compiled(m, comp_level));
266 }
267
268 bool CompilationPolicy::is_compilation_enabled() {
269 // NOTE: CompileBroker::should_compile_new_jobs() checks for UseCompiler
270 return CompileBroker::should_compile_new_jobs();
271 }
272
273 CompileTask* CompilationPolicy::select_task_helper(CompileQueue* compile_queue) {
274 // Remove unloaded methods from the queue
275 for (CompileTask* task = compile_queue->first(); task != nullptr; ) {
276 CompileTask* next = task->next();
277 if (task->is_unloaded()) {
278 compile_queue->remove_and_mark_stale(task);
279 }
280 task = next;
281 }
282 #if INCLUDE_JVMCI
283 if (UseJVMCICompiler && !BackgroundCompilation) {
284 /*
285 * In blocking compilation mode, the CompileBroker will make
286 * compilations submitted by a JVMCI compiler thread non-blocking. These
287 * compilations should be scheduled after all blocking compilations
288 * to service non-compiler related compilations sooner and reduce the
289 * chance of such compilations timing out.
290 */
291 for (CompileTask* task = compile_queue->first(); task != nullptr; task = task->next()) {
292 if (task->is_blocking()) {
293 return task;
294 }
295 }
296 }
297 #endif
298 return compile_queue->first();
299 }
300
301 // Simple methods are as good being compiled with C1 as C2.
302 // Determine if a given method is such a case.
303 bool CompilationPolicy::is_trivial(const methodHandle& method) {
304 if (method->is_accessor() ||
305 method->is_constant_getter()) {
306 return true;
307 }
308 return false;
309 }
310
311 bool CompilationPolicy::force_comp_at_level_simple(const methodHandle& method) {
312 if (CompilationModeFlag::quick_internal()) {
313 #if INCLUDE_JVMCI
314 if (UseJVMCICompiler) {
315 AbstractCompiler* comp = CompileBroker::compiler(CompLevel_full_optimization);
316 if (comp != nullptr && comp->is_jvmci() && ((JVMCICompiler*) comp)->force_comp_at_level_simple(method)) {
317 return true;
318 }
319 }
320 #endif
321 }
322 return false;
323 }
324
325 CompLevel CompilationPolicy::comp_level(Method* method) {
326 nmethod *nm = method->code();
327 if (nm != nullptr && nm->is_in_use()) {
328 return (CompLevel)nm->comp_level();
329 }
330 return CompLevel_none;
331 }
332
333 // Call and loop predicates determine whether a transition to a higher
334 // compilation level should be performed (pointers to predicate functions
335 // are passed to common()).
336 // Tier?LoadFeedback is basically a coefficient that determines of
337 // how many methods per compiler thread can be in the queue before
338 // the threshold values double.
339 class LoopPredicate : AllStatic {
340 public:
341 static bool apply_scaled(const methodHandle& method, CompLevel cur_level, int i, int b, double scale) {
342 double threshold_scaling;
343 if (CompilerOracle::has_option_value(method, CompileCommandEnum::CompileThresholdScaling, threshold_scaling)) {
344 scale *= threshold_scaling;
345 }
346 switch(cur_level) {
347 case CompLevel_none:
348 case CompLevel_limited_profile:
349 return b >= Tier3BackEdgeThreshold * scale;
350 case CompLevel_full_profile:
351 return b >= Tier4BackEdgeThreshold * scale;
352 default:
353 return true;
354 }
355 }
356
357 static bool apply(const methodHandle& method, CompLevel cur_level, int i, int b) {
358 double k = 1;
359 switch(cur_level) {
360 case CompLevel_none:
361 // Fall through
362 case CompLevel_limited_profile: {
363 k = CompilationPolicy::threshold_scale(CompLevel_full_profile, Tier3LoadFeedback);
364 break;
365 }
366 case CompLevel_full_profile: {
367 k = CompilationPolicy::threshold_scale(CompLevel_full_optimization, Tier4LoadFeedback);
368 break;
369 }
370 default:
371 return true;
372 }
373 return apply_scaled(method, cur_level, i, b, k);
374 }
375 };
376
377 class CallPredicate : AllStatic {
378 public:
379 static bool apply_scaled(const methodHandle& method, CompLevel cur_level, int i, int b, double scale) {
380 double threshold_scaling;
381 if (CompilerOracle::has_option_value(method, CompileCommandEnum::CompileThresholdScaling, threshold_scaling)) {
382 scale *= threshold_scaling;
383 }
384 switch(cur_level) {
385 case CompLevel_none:
386 case CompLevel_limited_profile:
387 return (i >= Tier3InvocationThreshold * scale) ||
388 (i >= Tier3MinInvocationThreshold * scale && i + b >= Tier3CompileThreshold * scale);
389 case CompLevel_full_profile:
390 return (i >= Tier4InvocationThreshold * scale) ||
391 (i >= Tier4MinInvocationThreshold * scale && i + b >= Tier4CompileThreshold * scale);
392 default:
393 return true;
394 }
395 }
396
397 static bool apply(const methodHandle& method, CompLevel cur_level, int i, int b) {
398 double k = 1;
399 switch(cur_level) {
400 case CompLevel_none:
401 case CompLevel_limited_profile: {
402 k = CompilationPolicy::threshold_scale(CompLevel_full_profile, Tier3LoadFeedback);
403 break;
404 }
405 case CompLevel_full_profile: {
406 k = CompilationPolicy::threshold_scale(CompLevel_full_optimization, Tier4LoadFeedback);
407 break;
408 }
409 default:
410 return true;
411 }
412 return apply_scaled(method, cur_level, i, b, k);
413 }
414 };
415
416 double CompilationPolicy::threshold_scale(CompLevel level, int feedback_k) {
417 int comp_count = compiler_count(level);
418 if (comp_count > 0 && feedback_k > 0) {
419 double queue_size = CompileBroker::queue_size(level);
420 double k = (double)queue_size / ((double)feedback_k * (double)comp_count) + 1;
421
422 // Increase C1 compile threshold when the code cache is filled more
423 // than specified by IncreaseFirstTierCompileThresholdAt percentage.
424 // The main intention is to keep enough free space for C2 compiled code
425 // to achieve peak performance if the code cache is under stress.
426 if (CompilerConfig::is_tiered() && !CompilationModeFlag::disable_intermediate() && is_c1_compile(level)) {
427 double current_reverse_free_ratio = CodeCache::reverse_free_ratio();
428 if (current_reverse_free_ratio > _increase_threshold_at_ratio) {
429 k *= exp(current_reverse_free_ratio - _increase_threshold_at_ratio);
430 }
431 }
432 return k;
433 }
434 return 1;
435 }
436
437 void CompilationPolicy::print_counters_on(outputStream* st, const char* prefix, Method* m) {
438 int invocation_count = m->invocation_count();
439 int backedge_count = m->backedge_count();
440 MethodData* mdh = m->method_data();
441 int mdo_invocations = 0, mdo_backedges = 0;
442 int mdo_invocations_start = 0, mdo_backedges_start = 0;
443 if (mdh != nullptr) {
444 mdo_invocations = mdh->invocation_count();
445 mdo_backedges = mdh->backedge_count();
446 mdo_invocations_start = mdh->invocation_count_start();
447 mdo_backedges_start = mdh->backedge_count_start();
448 }
449 st->print(" %stotal=%d,%d %smdo=%d(%d),%d(%d)", prefix,
450 invocation_count, backedge_count, prefix,
451 mdo_invocations, mdo_invocations_start,
452 mdo_backedges, mdo_backedges_start);
453 st->print(" %smax levels=%d,%d", prefix, m->highest_comp_level(), m->highest_osr_comp_level());
454 }
455
456 void CompilationPolicy::print_training_data_on(outputStream* st, const char* prefix, Method* method, CompLevel cur_level) {
457 methodHandle m(Thread::current(), method);
458 st->print(" %smtd: ", prefix);
459 MethodTrainingData* mtd = MethodTrainingData::find(m);
460 if (mtd == nullptr) {
461 st->print("null");
462 } else {
463 if (should_delay_standard_transition(m, cur_level, mtd)) {
464 st->print("delayed, ");
465 }
466 MethodData* md = mtd->final_profile();
467 st->print("mdo=");
468 if (md == nullptr) {
469 st->print("null");
470 } else {
471 int mdo_invocations = md->invocation_count();
472 int mdo_backedges = md->backedge_count();
473 int mdo_invocations_start = md->invocation_count_start();
474 int mdo_backedges_start = md->backedge_count_start();
475 st->print("%d(%d), %d(%d)", mdo_invocations, mdo_invocations_start, mdo_backedges, mdo_backedges_start);
476 }
477 CompileTrainingData* ctd = mtd->last_toplevel_compile(CompLevel_full_optimization);
478 st->print(", deps=");
479 if (ctd == nullptr) {
480 st->print("null");
481 } else {
482 st->print("%d", ctd->init_deps_left_acquire());
483 }
484 }
485 }
486
487 // Print an event.
488 void CompilationPolicy::print_event_on(outputStream *st, EventType type, Method* m, Method* im, int bci, CompLevel level) {
489 bool inlinee_event = m != im;
490
491 st->print("%lf: [", os::elapsedTime());
492
493 switch(type) {
494 case CALL:
495 st->print("call");
496 break;
497 case LOOP:
498 st->print("loop");
499 break;
500 case COMPILE:
501 st->print("compile");
502 break;
503 case FORCE_COMPILE:
504 st->print("force-compile");
505 break;
506 case FORCE_RECOMPILE:
507 st->print("force-recompile");
508 break;
509 case REMOVE_FROM_QUEUE:
510 st->print("remove-from-queue");
511 break;
512 case UPDATE_IN_QUEUE:
513 st->print("update-in-queue");
514 break;
515 case REPROFILE:
516 st->print("reprofile");
517 break;
518 case MAKE_NOT_ENTRANT:
519 st->print("make-not-entrant");
520 break;
521 default:
522 st->print("unknown");
523 }
524
525 st->print(" level=%d ", level);
526
527 ResourceMark rm;
528 char *method_name = m->name_and_sig_as_C_string();
529 st->print("[%s", method_name);
530 if (inlinee_event) {
531 char *inlinee_name = im->name_and_sig_as_C_string();
532 st->print(" [%s]] ", inlinee_name);
533 }
534 else st->print("] ");
535 st->print("@%d queues=%d,%d", bci, CompileBroker::queue_size(CompLevel_full_profile),
536 CompileBroker::queue_size(CompLevel_full_optimization));
537
538 st->print(" rate=");
539 if (m->prev_time() == 0) st->print("n/a");
540 else st->print("%f", m->rate());
541
542 RecompilationPolicy::print_load_average(st);
543
544 st->print(" k=%.2lf,%.2lf", threshold_scale(CompLevel_full_profile, Tier3LoadFeedback),
545 threshold_scale(CompLevel_full_optimization, Tier4LoadFeedback));
546
547 if (type != COMPILE) {
548 print_counters_on(st, "", m);
549 if (inlinee_event) {
550 print_counters_on(st, "inlinee ", im);
551 }
552 st->print(" compilable=");
553 bool need_comma = false;
554 if (!m->is_not_compilable(CompLevel_full_profile)) {
555 st->print("c1");
556 need_comma = true;
557 }
558 if (!m->is_not_osr_compilable(CompLevel_full_profile)) {
559 if (need_comma) st->print(",");
560 st->print("c1-osr");
561 need_comma = true;
562 }
563 if (!m->is_not_compilable(CompLevel_full_optimization)) {
564 if (need_comma) st->print(",");
565 st->print("c2");
566 need_comma = true;
567 }
568 if (!m->is_not_osr_compilable(CompLevel_full_optimization)) {
569 if (need_comma) st->print(",");
570 st->print("c2-osr");
571 }
572 st->print(" status=");
573 if (m->queued_for_compilation()) {
574 st->print("in-queue");
575 } else st->print("idle");
576
577 print_training_data_on(st, "", m, level);
578 if (inlinee_event) {
579 print_training_data_on(st, "inlinee ", im, level);
580 }
581 }
582 st->print_cr("]");
583
584 }
585
586 void CompilationPolicy::print_event(EventType type, Method* m, Method* im, int bci, CompLevel level) {
587 stringStream s;
588 print_event_on(&s, type, m, im, bci, level);
589 ResourceMark rm;
590 tty->print("%s", s.as_string());
591 }
592
593 void CompilationPolicy::initialize() {
594 if (!CompilerConfig::is_interpreter_only()) {
595 int count = CICompilerCount;
596 bool c1_only = CompilerConfig::is_c1_only();
597 bool c2_only = CompilerConfig::is_c2_or_jvmci_compiler_only();
598 int min_count = (c1_only || c2_only) ? 1 : 2;
599
600 #ifdef _LP64
601 // Turn on ergonomic compiler count selection
602 if (AOTCodeCache::maybe_dumping_code()) {
603 // Assembly phase runs C1 and C2 compilation in separate phases,
604 // and can use all the CPU threads it can reach. Adjust the common
605 // options before policy starts overwriting them.
606 FLAG_SET_ERGO_IF_DEFAULT(UseDynamicNumberOfCompilerThreads, false);
607 FLAG_SET_ERGO_IF_DEFAULT(CICompilerCountPerCPU, false);
608 if (FLAG_IS_DEFAULT(CICompilerCount)) {
609 count = MAX2(count, os::active_processor_count());
610 }
611 }
612 if (FLAG_IS_DEFAULT(CICompilerCountPerCPU) && FLAG_IS_DEFAULT(CICompilerCount)) {
613 FLAG_SET_DEFAULT(CICompilerCountPerCPU, true);
614 }
615 if (CICompilerCountPerCPU) {
616 // Simple log n seems to grow too slowly for tiered, try something faster: log n * log log n
617 int log_cpu = log2i(os::active_processor_count());
618 int loglog_cpu = log2i(MAX2(log_cpu, 1));
619 count = MAX2(log_cpu * loglog_cpu * 3 / 2, min_count);
620 }
621 if (FLAG_IS_DEFAULT(CICompilerCount)) {
622 // Make sure there is enough space in the code cache to hold all the compiler buffers
623 size_t c1_size = 0;
624 #ifdef COMPILER1
625 c1_size = Compiler::code_buffer_size();
626 #endif
627 size_t c2_size = 0;
628 #ifdef COMPILER2
629 c2_size = C2Compiler::initial_code_buffer_size();
630 #endif
631 size_t buffer_size = 0;
632 if (c1_only) {
633 buffer_size = c1_size;
634 } else if (c2_only) {
635 buffer_size = c2_size;
636 } else {
637 buffer_size = c1_size / 3 + 2 * c2_size / 3;
638 }
639 size_t max_count = (NonNMethodCodeHeapSize - (CodeCacheMinimumUseSpace DEBUG_ONLY(* 3))) / buffer_size;
640 if ((size_t)count > max_count) {
641 // Lower the compiler count such that all buffers fit into the code cache
642 count = MAX2((int)max_count, min_count);
643 }
644 FLAG_SET_ERGO(CICompilerCount, count);
645 }
646 #else
647 // On 32-bit systems, the number of compiler threads is limited to 3.
648 // On these systems, the virtual address space available to the JVM
649 // is usually limited to 2-4 GB (the exact value depends on the platform).
650 // As the compilers (especially C2) can consume a large amount of
651 // memory, scaling the number of compiler threads with the number of
652 // available cores can result in the exhaustion of the address space
653 /// available to the VM and thus cause the VM to crash.
654 if (FLAG_IS_DEFAULT(CICompilerCount)) {
655 count = 3;
656 FLAG_SET_ERGO(CICompilerCount, count);
657 }
658 #endif // _LP64
659
660 if (c1_only) {
661 // No C2 compiler threads are needed
662 set_c1_count(count);
663 } else if (c2_only) {
664 // No C1 compiler threads are needed
665 set_c2_count(count);
666 } else {
667 #if INCLUDE_JVMCI
668 if (UseJVMCICompiler && UseJVMCINativeLibrary) {
669 int libjvmci_count = MAX2((int) (count * JVMCINativeLibraryThreadFraction), 1);
670 int c1_count = MAX2(count - libjvmci_count, 1);
671 set_c2_count(libjvmci_count);
672 set_c1_count(c1_count);
673 } else
674 #endif
675 {
676 set_c1_count(MAX2(count / 3, 1));
677 set_c2_count(MAX2(count - c1_count(), 1));
678 }
679 }
680 if (AOTCodeCache::is_code_load_thread_on()) {
681 set_ac_count((c1_only || c2_only) ? 1 : 2); // At minimum we need 2 threads to load C1 and C2 AOT code in parallel
682 }
683 assert(count == c1_count() + c2_count(), "inconsistent compiler thread count");
684 set_increase_threshold_at_ratio();
685 } else {
686 // Interpreter mode creates no compilers
687 FLAG_SET_ERGO(CICompilerCount, 0);
688 }
689 set_start_time(nanos_to_millis(os::javaTimeNanos()));
690 }
691
692
693 #ifdef ASSERT
694 bool CompilationPolicy::verify_level(CompLevel level) {
695 if (TieredCompilation && level > TieredStopAtLevel) {
696 return false;
697 }
698 // Check if there is a compiler to process the requested level
699 if (!CompilerConfig::is_c1_enabled() && is_c1_compile(level)) {
700 return false;
701 }
702 if (!CompilerConfig::is_c2_or_jvmci_compiler_enabled() && is_c2_compile(level)) {
703 return false;
704 }
705
706 // Interpreter level is always valid.
707 if (level == CompLevel_none) {
708 return true;
709 }
710 if (CompilationModeFlag::normal()) {
711 return true;
712 } else if (CompilationModeFlag::quick_only()) {
713 return level == CompLevel_simple;
714 } else if (CompilationModeFlag::high_only()) {
715 return level == CompLevel_full_optimization;
716 } else if (CompilationModeFlag::high_only_quick_internal()) {
717 return level == CompLevel_full_optimization || level == CompLevel_simple;
718 }
719 return false;
720 }
721 #endif
722
723
724 CompLevel CompilationPolicy::highest_compile_level() {
725 CompLevel level = CompLevel_none;
726 // Setup the maximum level available for the current compiler configuration.
727 if (!CompilerConfig::is_interpreter_only()) {
728 if (CompilerConfig::is_c2_or_jvmci_compiler_enabled()) {
729 level = CompLevel_full_optimization;
730 } else if (CompilerConfig::is_c1_enabled()) {
731 if (CompilerConfig::is_c1_simple_only()) {
732 level = CompLevel_simple;
733 } else {
734 level = CompLevel_full_profile;
735 }
736 }
737 }
738 // Clamp the maximum level with TieredStopAtLevel.
739 if (TieredCompilation) {
740 level = MIN2(level, (CompLevel) TieredStopAtLevel);
741 }
742
743 // Fix it up if after the clamping it has become invalid.
744 // Bring it monotonically down depending on the next available level for
745 // the compilation mode.
746 if (!CompilationModeFlag::normal()) {
747 // a) quick_only - levels 2,3,4 are invalid; levels -1,0,1 are valid;
748 // b) high_only - levels 1,2,3 are invalid; levels -1,0,4 are valid;
749 // c) high_only_quick_internal - levels 2,3 are invalid; levels -1,0,1,4 are valid.
750 if (CompilationModeFlag::quick_only()) {
751 if (level == CompLevel_limited_profile || level == CompLevel_full_profile || level == CompLevel_full_optimization) {
752 level = CompLevel_simple;
753 }
754 } else if (CompilationModeFlag::high_only()) {
755 if (level == CompLevel_simple || level == CompLevel_limited_profile || level == CompLevel_full_profile) {
756 level = CompLevel_none;
757 }
758 } else if (CompilationModeFlag::high_only_quick_internal()) {
759 if (level == CompLevel_limited_profile || level == CompLevel_full_profile) {
760 level = CompLevel_simple;
761 }
762 }
763 }
764
765 assert(verify_level(level), "Invalid highest compilation level: %d", level);
766 return level;
767 }
768
769 CompLevel CompilationPolicy::limit_level(CompLevel level) {
770 level = MIN2(level, highest_compile_level());
771 assert(verify_level(level), "Invalid compilation level: %d", level);
772 return level;
773 }
774
775 CompLevel CompilationPolicy::initial_compile_level(const methodHandle& method) {
776 CompLevel level = CompLevel_any;
777 if (CompilationModeFlag::normal()) {
778 level = CompLevel_full_profile;
779 } else if (CompilationModeFlag::quick_only()) {
780 level = CompLevel_simple;
781 } else if (CompilationModeFlag::high_only()) {
782 level = CompLevel_full_optimization;
783 } else if (CompilationModeFlag::high_only_quick_internal()) {
784 if (force_comp_at_level_simple(method)) {
785 level = CompLevel_simple;
786 } else {
787 level = CompLevel_full_optimization;
788 }
789 }
790 assert(level != CompLevel_any, "Unhandled compilation mode");
791 return limit_level(level);
792 }
793
794 // Set carry flags on the counters if necessary
795 void CompilationPolicy::handle_counter_overflow(const methodHandle& method) {
796 MethodCounters *mcs = method->method_counters();
797 if (mcs != nullptr) {
798 mcs->invocation_counter()->set_carry_on_overflow();
799 mcs->backedge_counter()->set_carry_on_overflow();
800 }
801 MethodData* mdo = method->method_data();
802 if (mdo != nullptr) {
803 mdo->invocation_counter()->set_carry_on_overflow();
804 mdo->backedge_counter()->set_carry_on_overflow();
805 }
806 }
807
808 // Called with the queue locked and with at least one element
809 CompileTask* CompilationPolicy::select_task(CompileQueue* compile_queue, JavaThread* THREAD) {
810 CompileTask *max_blocking_task = nullptr;
811 CompileTask *max_task = nullptr;
812 Method* max_method = nullptr;
813
814 int64_t t = nanos_to_millis(os::javaTimeNanos());
815 // Iterate through the queue and find a method with a maximum rate.
816 for (CompileTask* task = compile_queue->first(); task != nullptr;) {
817 CompileTask* next_task = task->next();
818 // If a method was unloaded or has been stale for some time, remove it from the queue.
819 // Blocking tasks and tasks submitted from whitebox API don't become stale
820 if (task->is_unloaded()) {
821 compile_queue->remove_and_mark_stale(task);
822 task = next_task;
823 continue;
824 }
825 if (task->is_aot_load()) {
826 // AOTCodeCache tasks are on separate queue, and they should load fast. There is no need to walk
827 // the rest of the queue, just take the task and go.
828 return task;
829 }
830 if (task->is_blocking() && task->compile_reason() == CompileTask::Reason_Whitebox) {
831 // CTW tasks, submitted as blocking Whitebox requests, do not participate in rate
832 // selection and/or any level adjustments. Just return them in order.
833 return task;
834 }
835 Method* method = task->method();
836 methodHandle mh(THREAD, method);
837 if (task->can_become_stale() && is_stale(t, TieredCompileTaskTimeout, mh) && !is_old(mh)) {
838 if (PrintTieredEvents) {
839 print_event(REMOVE_FROM_QUEUE, method, method, task->osr_bci(), (CompLevel) task->comp_level());
840 }
841 method->clear_queued_for_compilation();
842 method->set_pending_queue_processed(false);
843 compile_queue->remove_and_mark_stale(task);
844 task = next_task;
845 continue;
846 }
847 update_rate(t, mh);
848 if (max_task == nullptr || compare_methods(method, max_method) || compare_tasks(task, max_task)) {
849 // Select a method with the highest rate
850 max_task = task;
851 max_method = method;
852 }
853
854 if (task->is_blocking()) {
855 if (max_blocking_task == nullptr || compare_methods(method, max_blocking_task->method())) {
856 max_blocking_task = task;
857 }
858 }
859
860 task = next_task;
861 }
862
863 if (max_blocking_task != nullptr) {
864 // In blocking compilation mode, the CompileBroker will make
865 // compilations submitted by a JVMCI compiler thread non-blocking. These
866 // compilations should be scheduled after all blocking compilations
867 // to service non-compiler related compilations sooner and reduce the
868 // chance of such compilations timing out.
869 max_task = max_blocking_task;
870 max_method = max_task->method();
871 }
872
873 methodHandle max_method_h(THREAD, max_method);
874
875 if (max_task != nullptr && max_task->comp_level() == CompLevel_full_profile && TieredStopAtLevel > CompLevel_full_profile &&
876 max_method != nullptr && is_method_profiled(max_method_h) && !Arguments::is_compiler_only()) {
877 max_task->set_comp_level(CompLevel_limited_profile);
878
879 if (CompileBroker::compilation_is_complete(max_method_h(), max_task->osr_bci(), CompLevel_limited_profile,
880 true /* requires_online_compilation */,
881 CompileTask::Reason_None)) {
882 if (PrintTieredEvents) {
883 print_event(REMOVE_FROM_QUEUE, max_method, max_method, max_task->osr_bci(), (CompLevel)max_task->comp_level());
884 }
885 compile_queue->remove_and_mark_stale(max_task);
886 max_method->clear_queued_for_compilation();
887 return nullptr;
888 }
889
890 if (PrintTieredEvents) {
891 print_event(UPDATE_IN_QUEUE, max_method, max_method, max_task->osr_bci(), (CompLevel)max_task->comp_level());
892 }
893 }
894
895 return max_task;
896 }
897
898 void CompilationPolicy::reprofile(ScopeDesc* trap_scope, bool is_osr) {
899 for (ScopeDesc* sd = trap_scope;; sd = sd->sender()) {
900 if (PrintTieredEvents) {
901 print_event(REPROFILE, sd->method(), sd->method(), InvocationEntryBci, CompLevel_none);
902 }
903 MethodData* mdo = sd->method()->method_data();
904 if (mdo != nullptr) {
905 mdo->reset_start_counters();
906 }
907 if (sd->is_top()) break;
908 }
909 }
910
911 nmethod* CompilationPolicy::event(const methodHandle& method, const methodHandle& inlinee,
912 int branch_bci, int bci, CompLevel comp_level, nmethod* nm, TRAPS) {
913 if (PrintTieredEvents) {
914 print_event(bci == InvocationEntryBci ? CALL : LOOP, method(), inlinee(), bci, comp_level);
915 }
916
917 if (comp_level == CompLevel_none &&
918 JvmtiExport::can_post_interpreter_events() &&
919 THREAD->is_interp_only_mode()) {
920 return nullptr;
921 }
922 if (ReplayCompiles) {
923 // Don't trigger other compiles in testing mode
924 return nullptr;
925 }
926
927 handle_counter_overflow(method);
928 if (method() != inlinee()) {
929 handle_counter_overflow(inlinee);
930 }
931
932 if (bci == InvocationEntryBci) {
933 method_invocation_event(method, inlinee, comp_level, nm, THREAD);
934 } else {
935 // method == inlinee if the event originated in the main method
936 method_back_branch_event(method, inlinee, bci, comp_level, nm, THREAD);
937 // Check if event led to a higher level OSR compilation
938 CompLevel expected_comp_level = MIN2(CompLevel_full_optimization, static_cast<CompLevel>(comp_level + 1));
939 if (!CompilationModeFlag::disable_intermediate() && inlinee->is_not_osr_compilable(expected_comp_level)) {
940 // It's not possible to reach the expected level so fall back to simple.
941 expected_comp_level = CompLevel_simple;
942 }
943 CompLevel max_osr_level = static_cast<CompLevel>(inlinee->highest_osr_comp_level());
944 if (max_osr_level >= expected_comp_level) { // fast check to avoid locking in a typical scenario
945 nmethod* osr_nm = inlinee->lookup_osr_nmethod_for(bci, expected_comp_level, false);
946 assert(osr_nm == nullptr || osr_nm->comp_level() >= expected_comp_level, "lookup_osr_nmethod_for is broken");
947 if (osr_nm != nullptr && osr_nm->comp_level() != comp_level) {
948 // Perform OSR with new nmethod
949 return osr_nm;
950 }
951 }
952 }
953 return nullptr;
954 }
955
956 // Check if the method can be compiled, change level if necessary
957 void CompilationPolicy::compile(const methodHandle& mh, int bci, CompLevel level, TRAPS) {
958 assert(verify_level(level), "Invalid compilation level requested: %d", level);
959
960 if (level == CompLevel_none) {
961 if (mh->has_compiled_code()) {
962 // Happens when we switch to interpreter to profile.
963 MutexLocker ml(Compile_lock);
964 NoSafepointVerifier nsv;
965 if (mh->has_compiled_code()) {
966 mh->code()->make_not_used();
967 }
968 // Deoptimize immediately (we don't have to wait for a compile).
969 JavaThread* jt = THREAD;
970 RegisterMap map(jt,
971 RegisterMap::UpdateMap::skip,
972 RegisterMap::ProcessFrames::include,
973 RegisterMap::WalkContinuation::skip);
974 frame fr = jt->last_frame().sender(&map);
975 Deoptimization::deoptimize_frame(jt, fr.id());
976 }
977 return;
978 }
979
980 // Check if the method can be compiled. Additional logic for TieredCompilation:
981 // If it cannot be compiled with C1, continue profiling in the interpreter
982 // and then compile with C2 (the transition function will request that,
983 // see common() ). If the method cannot be compiled with C2 but still can with C1, compile it with
984 // pure C1.
985 if ((bci == InvocationEntryBci && !can_be_compiled(mh, level))) {
986 if (!CompilationModeFlag::disable_intermediate() &&
987 level == CompLevel_full_optimization && can_be_compiled(mh, CompLevel_simple)) {
988 compile(mh, bci, CompLevel_simple, THREAD);
989 }
990 return;
991 }
992 if ((bci != InvocationEntryBci && !can_be_osr_compiled(mh, level))) {
993 if (!CompilationModeFlag::disable_intermediate() &&
994 level == CompLevel_full_optimization && can_be_osr_compiled(mh, CompLevel_simple)) {
995 nmethod* osr_nm = mh->lookup_osr_nmethod_for(bci, CompLevel_simple, false);
996 if (osr_nm != nullptr && osr_nm->comp_level() > CompLevel_simple) {
997 // Invalidate the existing OSR nmethod so that a compile at CompLevel_simple is permitted.
998 osr_nm->make_not_entrant(nmethod::InvalidationReason::OSR_INVALIDATION_FOR_COMPILING_WITH_C1);
999 }
1000 compile(mh, bci, CompLevel_simple, THREAD);
1001 }
1002 return;
1003 }
1004 if (bci != InvocationEntryBci && mh->is_not_osr_compilable(level)) {
1005 return;
1006 }
1007 if (!CompileBroker::compilation_is_in_queue(mh)) {
1008 if (PrintTieredEvents) {
1009 print_event(COMPILE, mh(), mh(), bci, level);
1010 }
1011 int hot_count = (bci == InvocationEntryBci) ? mh->invocation_count() : mh->backedge_count();
1012 update_rate(nanos_to_millis(os::javaTimeNanos()), mh);
1013 bool requires_online_compilation = true;
1014 if (TrainingData::have_data()) {
1015 MethodTrainingData* mtd = MethodTrainingData::find_fast(mh);
1016 if (mtd != nullptr) {
1017 CompileTrainingData* ctd = mtd->last_toplevel_compile(level);
1018 if (ctd != nullptr) {
1019 requires_online_compilation = (ctd->init_deps_left_acquire() > 0);
1020 }
1021 }
1022 }
1023 CompileBroker::compile_method(mh, bci, level, hot_count, requires_online_compilation, CompileTask::Reason_Tiered, THREAD);
1024 }
1025 }
1026
1027 // update_rate() is called from select_task() while holding a compile queue lock.
1028 void CompilationPolicy::update_rate(int64_t t, const methodHandle& method) {
1029 // Skip update if counters are absent.
1030 // Can't allocate them since we are holding compile queue lock.
1031 if (method->method_counters() == nullptr) return;
1032
1033 if (is_old(method)) {
1034 // We don't remove old methods from the queue,
1035 // so we can just zero the rate.
1036 method->set_rate(0);
1037 return;
1038 }
1039
1040 // We don't update the rate if we've just came out of a safepoint.
1041 // delta_s is the time since last safepoint in milliseconds.
1042 int64_t delta_s = t - SafepointTracing::end_of_last_safepoint_ms();
1043 int64_t delta_t = t - (method->prev_time() != 0 ? method->prev_time() : start_time()); // milliseconds since the last measurement
1044 // How many events were there since the last time?
1045 int event_count = method->invocation_count() + method->backedge_count();
1046 int delta_e = event_count - method->prev_event_count();
1047
1048 // We should be running for at least 1ms.
1049 if (delta_s >= TieredRateUpdateMinTime) {
1050 // And we must've taken the previous point at least 1ms before.
1051 if (delta_t >= TieredRateUpdateMinTime && delta_e > 0) {
1052 method->set_prev_time(t);
1053 method->set_prev_event_count(event_count);
1054 method->set_rate((float)delta_e / (float)delta_t); // Rate is events per millisecond
1055 } else {
1056 if (delta_t > TieredRateUpdateMaxTime && delta_e == 0) {
1057 // If nothing happened for 25ms, zero the rate. Don't modify prev values.
1058 method->set_rate(0);
1059 }
1060 }
1061 }
1062 }
1063
1064 // Check if this method has been stale for a given number of milliseconds.
1065 // See select_task().
1066 bool CompilationPolicy::is_stale(int64_t t, int64_t timeout, const methodHandle& method) {
1067 int64_t delta_s = t - SafepointTracing::end_of_last_safepoint_ms();
1068 int64_t delta_t = t - method->prev_time();
1069 if (delta_t > timeout && delta_s > timeout) {
1070 int event_count = method->invocation_count() + method->backedge_count();
1071 int delta_e = event_count - method->prev_event_count();
1072 // Return true if there were no events.
1073 return delta_e == 0;
1074 }
1075 return false;
1076 }
1077
1078 // We don't remove old methods from the compile queue even if they have
1079 // very low activity. See select_task().
1080 bool CompilationPolicy::is_old(const methodHandle& method) {
1081 int i = method->invocation_count();
1082 int b = method->backedge_count();
1083 double k = TieredOldPercentage / 100.0;
1084
1085 return CallPredicate::apply_scaled(method, CompLevel_none, i, b, k) || LoopPredicate::apply_scaled(method, CompLevel_none, i, b, k);
1086 }
1087
1088 double CompilationPolicy::weight(Method* method) {
1089 return (double)(method->rate() + 1) * (method->invocation_count() + 1) * (method->backedge_count() + 1);
1090 }
1091
1092 // Apply heuristics and return true if x should be compiled before y
1093 bool CompilationPolicy::compare_methods(Method* x, Method* y) {
1094 if (x->highest_comp_level() > y->highest_comp_level()) {
1095 // recompilation after deopt
1096 return true;
1097 } else
1098 if (x->highest_comp_level() == y->highest_comp_level()) {
1099 if (weight(x) > weight(y)) {
1100 return true;
1101 }
1102 }
1103 return false;
1104 }
1105
1106 bool CompilationPolicy::compare_tasks(CompileTask* x, CompileTask* y) {
1107 assert(!x->is_aot_load() && !y->is_aot_load(), "AOT code caching tasks are not expected here");
1108 if (x->compile_reason() != y->compile_reason() && x->compile_reason() == CompileTask::Reason_MustBeCompiled) {
1109 return true;
1110 }
1111 return false;
1112 }
1113
1114 // Is method profiled enough?
1115 bool CompilationPolicy::is_method_profiled(const methodHandle& method) {
1116 MethodData* mdo = method->method_data();
1117 if (mdo != nullptr) {
1118 int i = mdo->invocation_count_delta();
1119 int b = mdo->backedge_count_delta();
1120 return CallPredicate::apply_scaled(method, CompLevel_full_profile, i, b, 1);
1121 }
1122 return false;
1123 }
1124
1125
1126 // Determine is a method is mature.
1127 bool CompilationPolicy::is_mature(MethodData* mdo) {
1128 if (Arguments::is_compiler_only()) {
1129 // Always report profiles as immature with -Xcomp
1130 return false;
1131 }
1132 methodHandle mh(Thread::current(), mdo->method());
1133 if (mdo != nullptr) {
1134 int i = mdo->invocation_count();
1135 int b = mdo->backedge_count();
1136 double k = ProfileMaturityPercentage / 100.0;
1137 return CallPredicate::apply_scaled(mh, CompLevel_full_profile, i, b, k) || LoopPredicate::apply_scaled(mh, CompLevel_full_profile, i, b, k);
1138 }
1139 return false;
1140 }
1141
1142 // If a method is old enough and is still in the interpreter we would want to
1143 // start profiling without waiting for the compiled method to arrive.
1144 // We also take the load on compilers into the account.
1145 bool CompilationPolicy::should_create_mdo(const methodHandle& method, CompLevel cur_level) {
1146 if (cur_level != CompLevel_none || force_comp_at_level_simple(method) || CompilationModeFlag::quick_only() || !ProfileInterpreter) {
1147 return false;
1148 }
1149
1150 if (TrainingData::have_data()) {
1151 MethodTrainingData* mtd = MethodTrainingData::find_fast(method);
1152 if (mtd != nullptr && mtd->saw_level(CompLevel_full_optimization)) {
1153 return true;
1154 }
1155 }
1156
1157 if (is_old(method)) {
1158 return true;
1159 }
1160 int i = method->invocation_count();
1161 int b = method->backedge_count();
1162 double k = Tier0ProfilingStartPercentage / 100.0;
1163
1164 // If the top level compiler is not keeping up, delay profiling.
1165 if (CompileBroker::queue_size(CompLevel_full_optimization) <= Tier0Delay * compiler_count(CompLevel_full_optimization)) {
1166 return CallPredicate::apply_scaled(method, CompLevel_none, i, b, k) || LoopPredicate::apply_scaled(method, CompLevel_none, i, b, k);
1167 }
1168 return false;
1169 }
1170
1171 // Inlining control: if we're compiling a profiled method with C1 and the callee
1172 // is known to have OSRed in a C2 version, don't inline it.
1173 bool CompilationPolicy::should_not_inline(ciEnv* env, ciMethod* callee) {
1174 CompLevel comp_level = (CompLevel)env->comp_level();
1175 if (comp_level == CompLevel_full_profile ||
1176 comp_level == CompLevel_limited_profile) {
1177 return callee->highest_osr_comp_level() == CompLevel_full_optimization;
1178 }
1179 return false;
1180 }
1181
1182 // Create MDO if necessary.
1183 void CompilationPolicy::create_mdo(const methodHandle& mh, JavaThread* THREAD) {
1184 if (mh->is_native() ||
1185 mh->is_abstract() ||
1186 mh->is_accessor() ||
1187 mh->is_constant_getter()) {
1188 return;
1189 }
1190 if (mh->method_data() == nullptr) {
1191 Method::build_profiling_method_data(mh, CHECK_AND_CLEAR);
1192 }
1193 if (ProfileInterpreter && THREAD->has_last_Java_frame()) {
1194 MethodData* mdo = mh->method_data();
1195 if (mdo != nullptr) {
1196 frame last_frame = THREAD->last_frame();
1197 if (last_frame.is_interpreted_frame() && mh == last_frame.interpreter_frame_method()) {
1198 int bci = last_frame.interpreter_frame_bci();
1199 address dp = mdo->bci_to_dp(bci);
1200 last_frame.interpreter_frame_set_mdp(dp);
1201 }
1202 }
1203 }
1204 }
1205
1206 CompLevel CompilationPolicy::trained_transition_from_none(const methodHandle& method, CompLevel cur_level, MethodTrainingData* mtd, JavaThread* THREAD) {
1207 precond(mtd != nullptr);
1208 precond(cur_level == CompLevel_none);
1209
1210 if (mtd->only_inlined() && !mtd->saw_level(CompLevel_full_optimization)) {
1211 return CompLevel_none;
1212 }
1213
1214 bool training_has_profile = (mtd->final_profile() != nullptr);
1215 if (mtd->saw_level(CompLevel_full_optimization) && !training_has_profile) {
1216 return CompLevel_full_profile;
1217 }
1218
1219 CompLevel highest_training_level = static_cast<CompLevel>(mtd->highest_top_level());
1220 switch (highest_training_level) {
1221 case CompLevel_limited_profile:
1222 case CompLevel_full_profile:
1223 return CompLevel_limited_profile;
1224 case CompLevel_simple:
1225 return CompLevel_simple;
1226 case CompLevel_none:
1227 return CompLevel_none;
1228 default:
1229 break;
1230 }
1231
1232 // Now handle the case of level 4.
1233 assert(highest_training_level == CompLevel_full_optimization, "Unexpected compilation level: %d", highest_training_level);
1234 if (!training_has_profile) {
1235 // The method was a part of a level 4 compile, but doesn't have a stored profile,
1236 // we need to profile it.
1237 return CompLevel_full_profile;
1238 }
1239 const bool deopt = (static_cast<CompLevel>(method->highest_comp_level()) == CompLevel_full_optimization);
1240 // If we deopted, then we reprofile
1241 if (deopt && !is_method_profiled(method)) {
1242 return CompLevel_full_profile;
1243 }
1244
1245 CompileTrainingData* ctd = mtd->last_toplevel_compile(CompLevel_full_optimization);
1246 assert(ctd != nullptr, "Should have CTD for CompLevel_full_optimization");
1247 // With SkipTier2IfPossible and all deps satisfied, go to level 4 immediately
1248 if (SkipTier2IfPossible && ctd->init_deps_left_acquire() == 0) {
1249 if (method->method_data() == nullptr) {
1250 create_mdo(method, THREAD);
1251 }
1252 return CompLevel_full_optimization;
1253 }
1254
1255 // Otherwise go to level 2
1256 return CompLevel_limited_profile;
1257 }
1258
1259
1260 CompLevel CompilationPolicy::trained_transition_from_limited_profile(const methodHandle& method, CompLevel cur_level, MethodTrainingData* mtd, JavaThread* THREAD) {
1261 precond(mtd != nullptr);
1262 precond(cur_level == CompLevel_limited_profile);
1263
1264 // One of the main reasons that we can get here is that we're waiting for the stored C2 code to become ready.
1265
1266 // But first, check if we have a saved profile
1267 bool training_has_profile = (mtd->final_profile() != nullptr);
1268 if (!training_has_profile) {
1269 return CompLevel_full_profile;
1270 }
1271
1272
1273 assert(training_has_profile, "Have to have a profile to be here");
1274 // Check if the method is ready
1275 CompileTrainingData* ctd = mtd->last_toplevel_compile(CompLevel_full_optimization);
1276 if (ctd != nullptr && ctd->init_deps_left_acquire() == 0) {
1277 if (method->method_data() == nullptr) {
1278 create_mdo(method, THREAD);
1279 }
1280 return CompLevel_full_optimization;
1281 }
1282
1283 // Otherwise stay at the current level
1284 return CompLevel_limited_profile;
1285 }
1286
1287
1288 CompLevel CompilationPolicy::trained_transition_from_full_profile(const methodHandle& method, CompLevel cur_level, MethodTrainingData* mtd, JavaThread* THREAD) {
1289 precond(mtd != nullptr);
1290 precond(cur_level == CompLevel_full_profile);
1291
1292 CompLevel highest_training_level = static_cast<CompLevel>(mtd->highest_top_level());
1293 // We have method at the full profile level and we also know that it's possibly an important method.
1294 if (highest_training_level == CompLevel_full_optimization && !mtd->only_inlined()) {
1295 // Check if it is adequately profiled
1296 if (is_method_profiled(method)) {
1297 return CompLevel_full_optimization;
1298 }
1299 }
1300
1301 // Otherwise stay at the current level
1302 return CompLevel_full_profile;
1303 }
1304
1305 CompLevel CompilationPolicy::trained_transition(const methodHandle& method, CompLevel cur_level, MethodTrainingData* mtd, JavaThread* THREAD) {
1306 precond(MethodTrainingData::have_data());
1307
1308 // If there is no training data recorded for this method, bail out.
1309 if (mtd == nullptr) {
1310 return cur_level;
1311 }
1312
1313 CompLevel next_level = cur_level;
1314 switch(cur_level) {
1315 default: break;
1316 case CompLevel_none:
1317 next_level = trained_transition_from_none(method, cur_level, mtd, THREAD);
1318 break;
1319 case CompLevel_limited_profile:
1320 next_level = trained_transition_from_limited_profile(method, cur_level, mtd, THREAD);
1321 break;
1322 case CompLevel_full_profile:
1323 next_level = trained_transition_from_full_profile(method, cur_level, mtd, THREAD);
1324 break;
1325 }
1326
1327 // We don't have any special strategies for the C2-only compilation modes, so just fix up the levels for now.
1328 if (CompilationModeFlag::high_only_quick_internal() && CompLevel_simple < next_level && next_level < CompLevel_full_optimization) {
1329 return CompLevel_none;
1330 }
1331 if (CompilationModeFlag::high_only() && next_level < CompLevel_full_optimization) {
1332 return CompLevel_none;
1333 }
1334 return (cur_level != next_level) ? limit_level(next_level) : cur_level;
1335 }
1336
1337 /*
1338 * Method states:
1339 * 0 - interpreter (CompLevel_none)
1340 * 1 - pure C1 (CompLevel_simple)
1341 * 2 - C1 with invocation and backedge counting (CompLevel_limited_profile)
1342 * 3 - C1 with full profiling (CompLevel_full_profile)
1343 * 4 - C2 or Graal (CompLevel_full_optimization)
1344 *
1345 * Common state transition patterns:
1346 * a. 0 -> 3 -> 4.
1347 * The most common path. But note that even in this straightforward case
1348 * profiling can start at level 0 and finish at level 3.
1349 *
1350 * b. 0 -> 2 -> 3 -> 4.
1351 * This case occurs when the load on C2 is deemed too high. So, instead of transitioning
1352 * into state 3 directly and over-profiling while a method is in the C2 queue we transition to
1353 * level 2 and wait until the load on C2 decreases. This path is disabled for OSRs.
1354 *
1355 * c. 0 -> (3->2) -> 4.
1356 * In this case we enqueue a method for compilation at level 3, but the C1 queue is long enough
1357 * to enable the profiling to fully occur at level 0. In this case we change the compilation level
1358 * of the method to 2 while the request is still in-queue, because it'll allow it to run much faster
1359 * without full profiling while c2 is compiling.
1360 *
1361 * d. 0 -> 3 -> 1 or 0 -> 2 -> 1.
1362 * After a method was once compiled with C1 it can be identified as trivial and be compiled to
1363 * level 1. These transition can also occur if a method can't be compiled with C2 but can with C1.
1364 *
1365 * e. 0 -> 4.
1366 * This can happen if a method fails C1 compilation (it will still be profiled in the interpreter)
1367 * or because of a deopt that didn't require reprofiling (compilation won't happen in this case because
1368 * the compiled version already exists).
1369 *
1370 * Note that since state 0 can be reached from any other state via deoptimization different loops
1371 * are possible.
1372 *
1373 */
1374
1375 // Common transition function. Given a predicate determines if a method should transition to another level.
1376 template<typename Predicate>
1377 CompLevel CompilationPolicy::common(const methodHandle& method, CompLevel cur_level, JavaThread* THREAD, bool disable_feedback) {
1378 CompLevel next_level = cur_level;
1379
1380 if (force_comp_at_level_simple(method)) {
1381 next_level = CompLevel_simple;
1382 } else if (is_trivial(method) || method->is_native()) {
1383 // We do not care if there is profiling data for these methods, throw them to compiler.
1384 next_level = CompilationModeFlag::disable_intermediate() ? CompLevel_full_optimization : CompLevel_simple;
1385 } else if (MethodTrainingData::have_data()) {
1386 MethodTrainingData* mtd = MethodTrainingData::find_fast(method);
1387 if (mtd == nullptr) {
1388 // We haven't see compilations of this method in training. It's either very cold or the behavior changed.
1389 // Feed it to the standard TF with no profiling delay.
1390 next_level = standard_transition<Predicate>(method, cur_level, disable_feedback);
1391 } else {
1392 next_level = trained_transition(method, cur_level, mtd, THREAD);
1393 if (cur_level == next_level && !should_delay_standard_transition(method, cur_level, mtd)) {
1394 // trained_transtion() is going to return the same level if no startup/warmup optimizations apply.
1395 // In order to catch possible pathologies due to behavior change we feed the event to the regular
1396 // TF but with profiling delay.
1397 next_level = standard_transition<Predicate>(method, cur_level, disable_feedback);
1398 }
1399 }
1400 } else {
1401 next_level = standard_transition<Predicate>(method, cur_level, disable_feedback);
1402 }
1403 return (next_level != cur_level) ? limit_level(next_level) : next_level;
1404 }
1405
1406 bool CompilationPolicy::should_delay_standard_transition(const methodHandle& method, CompLevel cur_level, MethodTrainingData* mtd) {
1407 precond(mtd != nullptr);
1408 CompLevel highest_training_level = static_cast<CompLevel>(mtd->highest_top_level());
1409 if (highest_training_level != CompLevel_full_optimization && cur_level == CompLevel_limited_profile) {
1410 // This is a lukewarm method - it hasn't been compiled with C2 during the tranining run and is currently
1411 // running at level 2. Delay any further state changes until its counters exceed the training run counts.
1412 MethodCounters* mc = method->method_counters();
1413 if (mc == nullptr) {
1414 return false;
1415 }
1416 if (mc->invocation_counter()->carry() || mc->backedge_counter()->carry()) {
1417 return false;
1418 }
1419 if (static_cast<int>(mc->invocation_counter()->count()) <= mtd->invocation_count() &&
1420 static_cast<int>(mc->backedge_counter()->count()) <= mtd->backedge_count()) {
1421 return true;
1422 }
1423 }
1424 return false;
1425 }
1426
1427 template<typename Predicate>
1428 CompLevel CompilationPolicy::standard_transition(const methodHandle& method, CompLevel cur_level, bool disable_feedback) {
1429 CompLevel next_level = cur_level;
1430 switch(cur_level) {
1431 default: break;
1432 case CompLevel_none:
1433 next_level = transition_from_none<Predicate>(method, cur_level, disable_feedback);
1434 break;
1435 case CompLevel_limited_profile:
1436 next_level = transition_from_limited_profile<Predicate>(method, cur_level, disable_feedback);
1437 break;
1438 case CompLevel_full_profile:
1439 next_level = transition_from_full_profile<Predicate>(method, cur_level);
1440 break;
1441 }
1442 return next_level;
1443 }
1444
1445 template<typename Predicate>
1446 CompLevel CompilationPolicy::transition_from_none(const methodHandle& method, CompLevel cur_level, bool disable_feedback) {
1447 precond(cur_level == CompLevel_none);
1448 CompLevel next_level = cur_level;
1449 int i = method->invocation_count();
1450 int b = method->backedge_count();
1451 // If we were at full profile level, would we switch to full opt?
1452 if (transition_from_full_profile<Predicate>(method, CompLevel_full_profile) == CompLevel_full_optimization) {
1453 next_level = CompLevel_full_optimization;
1454 } else if (!CompilationModeFlag::disable_intermediate() && Predicate::apply(method, cur_level, i, b)) {
1455 // C1-generated fully profiled code is about 30% slower than the limited profile
1456 // code that has only invocation and backedge counters. The observation is that
1457 // if C2 queue is large enough we can spend too much time in the fully profiled code
1458 // while waiting for C2 to pick the method from the queue. To alleviate this problem
1459 // we introduce a feedback on the C2 queue size. If the C2 queue is sufficiently long
1460 // we choose to compile a limited profiled version and then recompile with full profiling
1461 // when the load on C2 goes down.
1462 if (!disable_feedback && CompileBroker::queue_size(CompLevel_full_optimization) > Tier3DelayOn * compiler_count(CompLevel_full_optimization)) {
1463 next_level = CompLevel_limited_profile;
1464 } else {
1465 next_level = CompLevel_full_profile;
1466 }
1467 }
1468 return next_level;
1469 }
1470
1471 template<typename Predicate>
1472 CompLevel CompilationPolicy::transition_from_full_profile(const methodHandle& method, CompLevel cur_level) {
1473 precond(cur_level == CompLevel_full_profile);
1474 CompLevel next_level = cur_level;
1475 MethodData* mdo = method->method_data();
1476 if (mdo != nullptr) {
1477 if (mdo->would_profile() || CompilationModeFlag::disable_intermediate()) {
1478 int mdo_i = mdo->invocation_count_delta();
1479 int mdo_b = mdo->backedge_count_delta();
1480 if (Predicate::apply(method, cur_level, mdo_i, mdo_b)) {
1481 next_level = CompLevel_full_optimization;
1482 }
1483 } else {
1484 next_level = CompLevel_full_optimization;
1485 }
1486 }
1487 return next_level;
1488 }
1489
1490 template<typename Predicate>
1491 CompLevel CompilationPolicy::transition_from_limited_profile(const methodHandle& method, CompLevel cur_level, bool disable_feedback) {
1492 precond(cur_level == CompLevel_limited_profile);
1493 CompLevel next_level = cur_level;
1494 int i = method->invocation_count();
1495 int b = method->backedge_count();
1496 MethodData* mdo = method->method_data();
1497 if (mdo != nullptr) {
1498 if (mdo->would_profile()) {
1499 if (disable_feedback || (CompileBroker::queue_size(CompLevel_full_optimization) <=
1500 Tier3DelayOff * compiler_count(CompLevel_full_optimization) &&
1501 Predicate::apply(method, cur_level, i, b))) {
1502 next_level = CompLevel_full_profile;
1503 }
1504 } else {
1505 next_level = CompLevel_full_optimization;
1506 }
1507 } else {
1508 // If there is no MDO we need to profile
1509 if (disable_feedback || (CompileBroker::queue_size(CompLevel_full_optimization) <=
1510 Tier3DelayOff * compiler_count(CompLevel_full_optimization) &&
1511 Predicate::apply(method, cur_level, i, b))) {
1512 next_level = CompLevel_full_profile;
1513 }
1514 }
1515 if (next_level == CompLevel_full_profile && is_method_profiled(method)) {
1516 next_level = CompLevel_full_optimization;
1517 }
1518 return next_level;
1519 }
1520
1521
1522 // Determine if a method should be compiled with a normal entry point at a different level.
1523 CompLevel CompilationPolicy::call_event(const methodHandle& method, CompLevel cur_level, JavaThread* THREAD) {
1524 CompLevel osr_level = MIN2((CompLevel) method->highest_osr_comp_level(), common<LoopPredicate>(method, cur_level, THREAD, true));
1525 CompLevel next_level = common<CallPredicate>(method, cur_level, THREAD, !TrainingData::have_data() && is_old(method));
1526
1527 // If OSR method level is greater than the regular method level, the levels should be
1528 // equalized by raising the regular method level in order to avoid OSRs during each
1529 // invocation of the method.
1530 if (osr_level == CompLevel_full_optimization && cur_level == CompLevel_full_profile) {
1531 MethodData* mdo = method->method_data();
1532 guarantee(mdo != nullptr, "MDO should not be nullptr");
1533 if (mdo->invocation_count() >= 1) {
1534 next_level = CompLevel_full_optimization;
1535 }
1536 } else {
1537 next_level = MAX2(osr_level, next_level);
1538 }
1539
1540 return next_level;
1541 }
1542
1543 // Determine if we should do an OSR compilation of a given method.
1544 CompLevel CompilationPolicy::loop_event(const methodHandle& method, CompLevel cur_level, JavaThread* THREAD) {
1545 CompLevel next_level = common<LoopPredicate>(method, cur_level, THREAD, true);
1546 if (cur_level == CompLevel_none) {
1547 // If there is a live OSR method that means that we deopted to the interpreter
1548 // for the transition.
1549 CompLevel osr_level = MIN2((CompLevel)method->highest_osr_comp_level(), next_level);
1550 if (osr_level > CompLevel_none) {
1551 return osr_level;
1552 }
1553 }
1554 return next_level;
1555 }
1556
1557 // Handle the invocation event.
1558 void CompilationPolicy::method_invocation_event(const methodHandle& mh, const methodHandle& imh,
1559 CompLevel level, nmethod* nm, TRAPS) {
1560 if (should_create_mdo(mh, level)) {
1561 create_mdo(mh, THREAD);
1562 }
1563 CompLevel next_level = call_event(mh, level, THREAD);
1564 if (next_level != level) {
1565 if (is_compilation_enabled() && !CompileBroker::compilation_is_in_queue(mh)) {
1566 compile(mh, InvocationEntryBci, next_level, THREAD);
1567 }
1568 }
1569 }
1570
1571 // Handle the back branch event. Notice that we can compile the method
1572 // with a regular entry from here.
1573 void CompilationPolicy::method_back_branch_event(const methodHandle& mh, const methodHandle& imh,
1574 int bci, CompLevel level, nmethod* nm, TRAPS) {
1575 if (should_create_mdo(mh, level)) {
1576 create_mdo(mh, THREAD);
1577 }
1578 // Check if MDO should be created for the inlined method
1579 if (should_create_mdo(imh, level)) {
1580 create_mdo(imh, THREAD);
1581 }
1582
1583 if (is_compilation_enabled()) {
1584 CompLevel next_osr_level = loop_event(imh, level, THREAD);
1585 CompLevel max_osr_level = (CompLevel)imh->highest_osr_comp_level();
1586 // At the very least compile the OSR version
1587 if (!CompileBroker::compilation_is_in_queue(imh) && (next_osr_level != level)) {
1588 compile(imh, bci, next_osr_level, CHECK);
1589 }
1590
1591 // Use loop event as an opportunity to also check if there's been
1592 // enough calls.
1593 CompLevel cur_level, next_level;
1594 if (mh() != imh()) { // If there is an enclosing method
1595 {
1596 guarantee(nm != nullptr, "Should have nmethod here");
1597 cur_level = comp_level(mh());
1598 next_level = call_event(mh, cur_level, THREAD);
1599
1600 if (max_osr_level == CompLevel_full_optimization) {
1601 // The inlinee OSRed to full opt, we need to modify the enclosing method to avoid deopts
1602 bool make_not_entrant = false;
1603 if (nm->is_osr_method()) {
1604 // This is an osr method, just make it not entrant and recompile later if needed
1605 make_not_entrant = true;
1606 } else {
1607 if (next_level != CompLevel_full_optimization) {
1608 // next_level is not full opt, so we need to recompile the
1609 // enclosing method without the inlinee
1610 cur_level = CompLevel_none;
1611 make_not_entrant = true;
1612 }
1613 }
1614 if (make_not_entrant) {
1615 if (PrintTieredEvents) {
1616 int osr_bci = nm->is_osr_method() ? nm->osr_entry_bci() : InvocationEntryBci;
1617 print_event(MAKE_NOT_ENTRANT, mh(), mh(), osr_bci, level);
1618 }
1619 nm->make_not_entrant(nmethod::InvalidationReason::OSR_INVALIDATION_BACK_BRANCH);
1620 }
1621 }
1622 // Fix up next_level if necessary to avoid deopts
1623 if (next_level == CompLevel_limited_profile && max_osr_level == CompLevel_full_profile) {
1624 next_level = CompLevel_full_profile;
1625 }
1626 if (cur_level != next_level) {
1627 if (!CompileBroker::compilation_is_in_queue(mh)) {
1628 compile(mh, InvocationEntryBci, next_level, THREAD);
1629 }
1630 }
1631 }
1632 } else {
1633 cur_level = comp_level(mh());
1634 next_level = call_event(mh, cur_level, THREAD);
1635 if (next_level != cur_level) {
1636 if (!CompileBroker::compilation_is_in_queue(mh)) {
1637 compile(mh, InvocationEntryBci, next_level, THREAD);
1638 }
1639 }
1640 }
1641 }
1642 }
1643