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