1 /* 2 * Copyright (c) 2010, 2020, Oracle and/or its affiliates. All rights reserved. 3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. 4 * 5 * This code is free software; you can redistribute it and/or modify it 6 * under the terms of the GNU General Public License version 2 only, as 7 * published by the Free Software Foundation. 8 * 9 * This code is distributed in the hope that it will be useful, but WITHOUT 10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 12 * version 2 for more details (a copy is included in the LICENSE file that 13 * accompanied this code). 14 * 15 * You should have received a copy of the GNU General Public License version 16 * 2 along with this work; if not, write to the Free Software Foundation, 17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. 18 * 19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA 20 * or visit www.oracle.com if you need additional information or have any 21 * questions. 22 * 23 */ 24 25 #include "precompiled.hpp" 26 #include "compiler/compileBroker.hpp" 27 #include "compiler/compilerOracle.hpp" 28 #include "compiler/tieredThresholdPolicy.hpp" 29 #include "memory/resourceArea.hpp" 30 #include "runtime/arguments.hpp" 31 #include "runtime/frame.inline.hpp" 32 #include "runtime/handles.inline.hpp" 33 #include "runtime/safepoint.hpp" 34 #include "runtime/safepointVerifiers.hpp" 35 #include "code/scopeDesc.hpp" 36 #include "oops/method.inline.hpp" 37 #if INCLUDE_JVMCI 38 #include "jvmci/jvmci.hpp" 39 #endif 40 41 #ifdef TIERED 42 43 #include "c1/c1_Compiler.hpp" 44 #include "opto/c2compiler.hpp" 45 46 bool TieredThresholdPolicy::call_predicate_helper(const methodHandle& method, CompLevel cur_level, int i, int b, double scale) { 47 double threshold_scaling; 48 if (CompilerOracle::has_option_value(method, "CompileThresholdScaling", threshold_scaling)) { 49 scale *= threshold_scaling; 50 } 51 switch(cur_level) { 52 case CompLevel_aot: 53 if (CompilationModeFlag::disable_intermediate()) { 54 return (i >= Tier0AOTInvocationThreshold * scale) || 55 (i >= Tier0AOTMinInvocationThreshold * scale && i + b >= Tier0AOTCompileThreshold * scale); 56 } else { 57 return (i >= Tier3AOTInvocationThreshold * scale) || 58 (i >= Tier3AOTMinInvocationThreshold * scale && i + b >= Tier3AOTCompileThreshold * scale); 59 } 60 case CompLevel_none: 61 if (CompilationModeFlag::disable_intermediate()) { 62 return (i >= Tier40InvocationThreshold * scale) || 63 (i >= Tier40MinInvocationThreshold * scale && i + b >= Tier40CompileThreshold * scale); 64 } 65 // Fall through 66 case CompLevel_limited_profile: 67 return (i >= Tier3InvocationThreshold * scale) || 68 (i >= Tier3MinInvocationThreshold * scale && i + b >= Tier3CompileThreshold * scale); 69 case CompLevel_full_profile: 70 return (i >= Tier4InvocationThreshold * scale) || 71 (i >= Tier4MinInvocationThreshold * scale && i + b >= Tier4CompileThreshold * scale); 72 default: 73 return true; 74 } 75 } 76 77 bool TieredThresholdPolicy::loop_predicate_helper(const methodHandle& method, CompLevel cur_level, int i, int b, double scale) { 78 double threshold_scaling; 79 if (CompilerOracle::has_option_value(method, "CompileThresholdScaling", threshold_scaling)) { 80 scale *= threshold_scaling; 81 } 82 switch(cur_level) { 83 case CompLevel_aot: 84 if (CompilationModeFlag::disable_intermediate()) { 85 return b >= Tier0AOTBackEdgeThreshold * scale; 86 } else { 87 return b >= Tier3AOTBackEdgeThreshold * scale; 88 } 89 case CompLevel_none: 90 if (CompilationModeFlag::disable_intermediate()) { 91 return b >= Tier40BackEdgeThreshold * scale; 92 } 93 // Fall through 94 case CompLevel_limited_profile: 95 return b >= Tier3BackEdgeThreshold * scale; 96 case CompLevel_full_profile: 97 return b >= Tier4BackEdgeThreshold * scale; 98 default: 99 return true; 100 } 101 } 102 103 // Simple methods are as good being compiled with C1 as C2. 104 // Determine if a given method is such a case. 105 bool TieredThresholdPolicy::is_trivial(Method* method) { 106 if (method->is_accessor() || 107 method->is_constant_getter()) { 108 return true; 109 } 110 return false; 111 } 112 113 bool TieredThresholdPolicy::force_comp_at_level_simple(const methodHandle& method) { 114 if (CompilationModeFlag::quick_internal()) { 115 #if INCLUDE_JVMCI 116 if (UseJVMCICompiler) { 117 AbstractCompiler* comp = CompileBroker::compiler(CompLevel_full_optimization); 118 if (comp != NULL && comp->is_jvmci() && ((JVMCICompiler*) comp)->force_comp_at_level_simple(method)) { 119 return true; 120 } 121 } 122 #endif 123 } 124 return false; 125 } 126 127 CompLevel TieredThresholdPolicy::comp_level(Method* method) { 128 CompiledMethod *nm = method->code(); 129 if (nm != NULL && nm->is_in_use()) { 130 return (CompLevel)nm->comp_level(); 131 } 132 return CompLevel_none; 133 } 134 135 void TieredThresholdPolicy::print_counters(const char* prefix, Method* m) { 136 int invocation_count = m->invocation_count(); 137 int backedge_count = m->backedge_count(); 138 MethodData* mdh = m->method_data(); 139 int mdo_invocations = 0, mdo_backedges = 0; 140 int mdo_invocations_start = 0, mdo_backedges_start = 0; 141 if (mdh != NULL) { 142 mdo_invocations = mdh->invocation_count(); 143 mdo_backedges = mdh->backedge_count(); 144 mdo_invocations_start = mdh->invocation_count_start(); 145 mdo_backedges_start = mdh->backedge_count_start(); 146 } 147 tty->print(" %stotal=%d,%d %smdo=%d(%d),%d(%d)", prefix, 148 invocation_count, backedge_count, prefix, 149 mdo_invocations, mdo_invocations_start, 150 mdo_backedges, mdo_backedges_start); 151 tty->print(" %smax levels=%d,%d", prefix, 152 m->highest_comp_level(), m->highest_osr_comp_level()); 153 } 154 155 // Print an event. 156 void TieredThresholdPolicy::print_event(EventType type, Method* m, Method* im, 157 int bci, CompLevel level) { 158 bool inlinee_event = m != im; 159 160 ttyLocker tty_lock; 161 tty->print("%lf: [", os::elapsedTime()); 162 163 switch(type) { 164 case CALL: 165 tty->print("call"); 166 break; 167 case LOOP: 168 tty->print("loop"); 169 break; 170 case COMPILE: 171 tty->print("compile"); 172 break; 173 case REMOVE_FROM_QUEUE: 174 tty->print("remove-from-queue"); 175 break; 176 case UPDATE_IN_QUEUE: 177 tty->print("update-in-queue"); 178 break; 179 case REPROFILE: 180 tty->print("reprofile"); 181 break; 182 case MAKE_NOT_ENTRANT: 183 tty->print("make-not-entrant"); 184 break; 185 default: 186 tty->print("unknown"); 187 } 188 189 tty->print(" level=%d ", level); 190 191 ResourceMark rm; 192 char *method_name = m->name_and_sig_as_C_string(); 193 tty->print("[%s", method_name); 194 if (inlinee_event) { 195 char *inlinee_name = im->name_and_sig_as_C_string(); 196 tty->print(" [%s]] ", inlinee_name); 197 } 198 else tty->print("] "); 199 tty->print("@%d queues=%d,%d", bci, CompileBroker::queue_size(CompLevel_full_profile), 200 CompileBroker::queue_size(CompLevel_full_optimization)); 201 202 tty->print(" rate="); 203 if (m->prev_time() == 0) tty->print("n/a"); 204 else tty->print("%f", m->rate()); 205 206 tty->print(" k=%.2lf,%.2lf", threshold_scale(CompLevel_full_profile, Tier3LoadFeedback), 207 threshold_scale(CompLevel_full_optimization, Tier4LoadFeedback)); 208 209 if (type != COMPILE) { 210 print_counters("", m); 211 if (inlinee_event) { 212 print_counters("inlinee ", im); 213 } 214 tty->print(" compilable="); 215 bool need_comma = false; 216 if (!m->is_not_compilable(CompLevel_full_profile)) { 217 tty->print("c1"); 218 need_comma = true; 219 } 220 if (!m->is_not_osr_compilable(CompLevel_full_profile)) { 221 if (need_comma) tty->print(","); 222 tty->print("c1-osr"); 223 need_comma = true; 224 } 225 if (!m->is_not_compilable(CompLevel_full_optimization)) { 226 if (need_comma) tty->print(","); 227 tty->print("c2"); 228 need_comma = true; 229 } 230 if (!m->is_not_osr_compilable(CompLevel_full_optimization)) { 231 if (need_comma) tty->print(","); 232 tty->print("c2-osr"); 233 } 234 tty->print(" status="); 235 if (m->queued_for_compilation()) { 236 tty->print("in-queue"); 237 } else tty->print("idle"); 238 } 239 tty->print_cr("]"); 240 } 241 242 243 void TieredThresholdPolicy::initialize() { 244 int count = CICompilerCount; 245 bool c1_only = TieredStopAtLevel < CompLevel_full_optimization || CompilationModeFlag::quick_only(); 246 bool c2_only = CompilationModeFlag::high_only(); 247 #ifdef _LP64 248 // Turn on ergonomic compiler count selection 249 if (FLAG_IS_DEFAULT(CICompilerCountPerCPU) && FLAG_IS_DEFAULT(CICompilerCount)) { 250 FLAG_SET_DEFAULT(CICompilerCountPerCPU, true); 251 } 252 if (CICompilerCountPerCPU) { 253 // Simple log n seems to grow too slowly for tiered, try something faster: log n * log log n 254 int log_cpu = log2_int(os::active_processor_count()); 255 int loglog_cpu = log2_int(MAX2(log_cpu, 1)); 256 count = MAX2(log_cpu * loglog_cpu * 3 / 2, 2); 257 // Make sure there is enough space in the code cache to hold all the compiler buffers 258 size_t c1_size = Compiler::code_buffer_size(); 259 size_t c2_size = C2Compiler::initial_code_buffer_size(); 260 size_t buffer_size = c1_only ? c1_size : (c1_size/3 + 2*c2_size/3); 261 int max_count = (ReservedCodeCacheSize - (CodeCacheMinimumUseSpace DEBUG_ONLY(* 3))) / (int)buffer_size; 262 if (count > max_count) { 263 // Lower the compiler count such that all buffers fit into the code cache 264 count = MAX2(max_count, c1_only ? 1 : 2); 265 } 266 FLAG_SET_ERGO(CICompilerCount, count); 267 } 268 #else 269 // On 32-bit systems, the number of compiler threads is limited to 3. 270 // On these systems, the virtual address space available to the JVM 271 // is usually limited to 2-4 GB (the exact value depends on the platform). 272 // As the compilers (especially C2) can consume a large amount of 273 // memory, scaling the number of compiler threads with the number of 274 // available cores can result in the exhaustion of the address space 275 /// available to the VM and thus cause the VM to crash. 276 if (FLAG_IS_DEFAULT(CICompilerCount)) { 277 count = 3; 278 FLAG_SET_ERGO(CICompilerCount, count); 279 } 280 #endif 281 282 if (c1_only) { 283 // No C2 compiler thread required 284 set_c1_count(count); 285 } else if (c2_only) { 286 set_c2_count(count); 287 } else { 288 set_c1_count(MAX2(count / 3, 1)); 289 set_c2_count(MAX2(count - c1_count(), 1)); 290 } 291 assert(count == c1_count() + c2_count(), "inconsistent compiler thread count"); 292 293 // Some inlining tuning 294 #ifdef X86 295 if (FLAG_IS_DEFAULT(InlineSmallCode)) { 296 FLAG_SET_DEFAULT(InlineSmallCode, 2000); 297 } 298 #endif 299 300 #if defined AARCH64 301 if (FLAG_IS_DEFAULT(InlineSmallCode)) { 302 FLAG_SET_DEFAULT(InlineSmallCode, 2500); 303 } 304 #endif 305 306 set_increase_threshold_at_ratio(); 307 set_start_time(nanos_to_millis(os::javaTimeNanos())); 308 } 309 310 311 #ifdef ASSERT 312 bool TieredThresholdPolicy::verify_level(CompLevel level) { 313 // AOT and interpreter levels are always valid. 314 if (level == CompLevel_aot || level == CompLevel_none) { 315 return true; 316 } 317 if (CompilationModeFlag::normal()) { 318 return true; 319 } else if (CompilationModeFlag::quick_only()) { 320 return level == CompLevel_simple; 321 } else if (CompilationModeFlag::high_only()) { 322 return level == CompLevel_full_optimization; 323 } else if (CompilationModeFlag::high_only_quick_internal()) { 324 return level == CompLevel_full_optimization || level == CompLevel_simple; 325 } 326 return false; 327 } 328 #endif 329 330 331 CompLevel TieredThresholdPolicy::limit_level(CompLevel level) { 332 if (CompilationModeFlag::quick_only()) { 333 level = MIN2(level, CompLevel_simple); 334 } 335 assert(verify_level(level), "Invalid compilation level %d", level); 336 if (level <= TieredStopAtLevel) { 337 return level; 338 } 339 // Some compilation levels are not valid depending on a compilation mode: 340 // a) quick_only - levels 2,3,4 are invalid; levels -1,0,1 are valid; 341 // b) high_only - levels 1,2,3 are invalid; levels -1,0,4 are valid; 342 // c) high_only_quick_internal - levels 2,3 are invalid; levels -1,0,1,4 are valid. 343 // The invalid levels are actually sequential so a single comparison is sufficient. 344 // Down here we already have (level > TieredStopAtLevel), which also implies that 345 // (TieredStopAtLevel < Highest Possible Level), so we need to return a level that is: 346 // a) a max level that is strictly less than the highest for a given compilation mode 347 // b) less or equal to TieredStopAtLevel 348 if (CompilationModeFlag::normal() || CompilationModeFlag::quick_only()) { 349 return (CompLevel)TieredStopAtLevel; 350 } 351 352 if (CompilationModeFlag::high_only() || CompilationModeFlag::high_only_quick_internal()) { 353 return MIN2(CompLevel_none, (CompLevel)TieredStopAtLevel); 354 } 355 356 ShouldNotReachHere(); 357 return CompLevel_any; 358 } 359 360 CompLevel TieredThresholdPolicy::initial_compile_level_helper(const methodHandle& method) { 361 if (CompilationModeFlag::normal()) { 362 return CompLevel_full_profile; 363 } else if (CompilationModeFlag::quick_only()) { 364 return CompLevel_simple; 365 } else if (CompilationModeFlag::high_only()) { 366 return CompLevel_full_optimization; 367 } else if (CompilationModeFlag::high_only_quick_internal()) { 368 if (force_comp_at_level_simple(method)) { 369 return CompLevel_simple; 370 } else { 371 return CompLevel_full_optimization; 372 } 373 } 374 ShouldNotReachHere(); 375 return CompLevel_any; 376 } 377 378 CompLevel TieredThresholdPolicy::initial_compile_level(const methodHandle& method) { 379 return limit_level(initial_compile_level_helper(method)); 380 } 381 382 // Set carry flags on the counters if necessary 383 void TieredThresholdPolicy::handle_counter_overflow(Method* method) { 384 MethodCounters *mcs = method->method_counters(); 385 if (mcs != NULL) { 386 mcs->invocation_counter()->set_carry_on_overflow(); 387 mcs->backedge_counter()->set_carry_on_overflow(); 388 } 389 MethodData* mdo = method->method_data(); 390 if (mdo != NULL) { 391 mdo->invocation_counter()->set_carry_on_overflow(); 392 mdo->backedge_counter()->set_carry_on_overflow(); 393 } 394 } 395 396 // Called with the queue locked and with at least one element 397 CompileTask* TieredThresholdPolicy::select_task(CompileQueue* compile_queue) { 398 CompileTask *max_blocking_task = NULL; 399 CompileTask *max_task = NULL; 400 Method* max_method = NULL; 401 jlong t = nanos_to_millis(os::javaTimeNanos()); 402 // Iterate through the queue and find a method with a maximum rate. 403 for (CompileTask* task = compile_queue->first(); task != NULL;) { 404 CompileTask* next_task = task->next(); 405 Method* method = task->method(); 406 // If a method was unloaded or has been stale for some time, remove it from the queue. 407 // Blocking tasks and tasks submitted from whitebox API don't become stale 408 if (task->is_unloaded() || (task->can_become_stale() && is_stale(t, TieredCompileTaskTimeout, method) && !is_old(method))) { 409 if (!task->is_unloaded()) { 410 if (PrintTieredEvents) { 411 print_event(REMOVE_FROM_QUEUE, method, method, task->osr_bci(), (CompLevel) task->comp_level()); 412 } 413 method->clear_queued_for_compilation(); 414 } 415 compile_queue->remove_and_mark_stale(task); 416 task = next_task; 417 continue; 418 } 419 update_rate(t, method); 420 if (max_task == NULL || compare_methods(method, max_method)) { 421 // Select a method with the highest rate 422 max_task = task; 423 max_method = method; 424 } 425 426 if (task->is_blocking()) { 427 if (max_blocking_task == NULL || compare_methods(method, max_blocking_task->method())) { 428 max_blocking_task = task; 429 } 430 } 431 432 task = next_task; 433 } 434 435 if (max_blocking_task != NULL) { 436 // In blocking compilation mode, the CompileBroker will make 437 // compilations submitted by a JVMCI compiler thread non-blocking. These 438 // compilations should be scheduled after all blocking compilations 439 // to service non-compiler related compilations sooner and reduce the 440 // chance of such compilations timing out. 441 max_task = max_blocking_task; 442 max_method = max_task->method(); 443 } 444 445 methodHandle max_method_h(Thread::current(), max_method); 446 447 if (max_task != NULL && max_task->comp_level() == CompLevel_full_profile && 448 TieredStopAtLevel > CompLevel_full_profile && 449 max_method != NULL && is_method_profiled(max_method_h)) { 450 max_task->set_comp_level(CompLevel_limited_profile); 451 452 if (CompileBroker::compilation_is_complete(max_method_h, max_task->osr_bci(), CompLevel_limited_profile)) { 453 if (PrintTieredEvents) { 454 print_event(REMOVE_FROM_QUEUE, max_method, max_method, max_task->osr_bci(), (CompLevel)max_task->comp_level()); 455 } 456 compile_queue->remove_and_mark_stale(max_task); 457 max_method->clear_queued_for_compilation(); 458 return NULL; 459 } 460 461 if (PrintTieredEvents) { 462 print_event(UPDATE_IN_QUEUE, max_method, max_method, max_task->osr_bci(), (CompLevel)max_task->comp_level()); 463 } 464 } 465 466 return max_task; 467 } 468 469 void TieredThresholdPolicy::reprofile(ScopeDesc* trap_scope, bool is_osr) { 470 for (ScopeDesc* sd = trap_scope;; sd = sd->sender()) { 471 if (PrintTieredEvents) { 472 print_event(REPROFILE, sd->method(), sd->method(), InvocationEntryBci, CompLevel_none); 473 } 474 MethodData* mdo = sd->method()->method_data(); 475 if (mdo != NULL) { 476 mdo->reset_start_counters(); 477 } 478 if (sd->is_top()) break; 479 } 480 } 481 482 nmethod* TieredThresholdPolicy::event(const methodHandle& method, const methodHandle& inlinee, 483 int branch_bci, int bci, CompLevel comp_level, CompiledMethod* nm, JavaThread* thread) { 484 if (comp_level == CompLevel_none && 485 JvmtiExport::can_post_interpreter_events() && 486 thread->is_interp_only_mode()) { 487 return NULL; 488 } 489 if (ReplayCompiles) { 490 // Don't trigger other compiles in testing mode 491 return NULL; 492 } 493 494 handle_counter_overflow(method()); 495 if (method() != inlinee()) { 496 handle_counter_overflow(inlinee()); 497 } 498 499 if (PrintTieredEvents) { 500 print_event(bci == InvocationEntryBci ? CALL : LOOP, method(), inlinee(), bci, comp_level); 501 } 502 503 if (bci == InvocationEntryBci) { 504 method_invocation_event(method, inlinee, comp_level, nm, thread); 505 } else { 506 // method == inlinee if the event originated in the main method 507 method_back_branch_event(method, inlinee, bci, comp_level, nm, thread); 508 // Check if event led to a higher level OSR compilation 509 CompLevel expected_comp_level = comp_level; 510 if (!CompilationModeFlag::disable_intermediate() && inlinee->is_not_osr_compilable(expected_comp_level)) { 511 // It's not possble to reach the expected level so fall back to simple. 512 expected_comp_level = CompLevel_simple; 513 } 514 nmethod* osr_nm = inlinee->lookup_osr_nmethod_for(bci, expected_comp_level, false); 515 assert(osr_nm == NULL || osr_nm->comp_level() >= expected_comp_level, "lookup_osr_nmethod_for is broken"); 516 if (osr_nm != NULL) { 517 // Perform OSR with new nmethod 518 return osr_nm; 519 } 520 } 521 return NULL; 522 } 523 524 // Check if the method can be compiled, change level if necessary 525 void TieredThresholdPolicy::compile(const methodHandle& mh, int bci, CompLevel level, JavaThread* thread) { 526 assert(verify_level(level) && level <= TieredStopAtLevel, "Invalid compilation level %d", level); 527 528 if (level == CompLevel_none) { 529 if (mh->has_compiled_code()) { 530 // Happens when we switch from AOT to interpreter to profile. 531 MutexLocker ml(Compile_lock); 532 NoSafepointVerifier nsv; 533 if (mh->has_compiled_code()) { 534 mh->code()->make_not_used(); 535 } 536 // Deoptimize immediately (we don't have to wait for a compile). 537 RegisterMap map(thread, false); 538 frame fr = thread->last_frame().sender(&map); 539 Deoptimization::deoptimize_frame(thread, fr.id()); 540 } 541 return; 542 } 543 if (level == CompLevel_aot) { 544 if (mh->has_aot_code()) { 545 if (PrintTieredEvents) { 546 print_event(COMPILE, mh(), mh(), bci, level); 547 } 548 MutexLocker ml(Compile_lock); 549 NoSafepointVerifier nsv; 550 if (mh->has_aot_code() && mh->code() != mh->aot_code()) { 551 mh->aot_code()->make_entrant(); 552 if (mh->has_compiled_code()) { 553 mh->code()->make_not_entrant(); 554 } 555 MutexLocker pl(CompiledMethod_lock, Mutex::_no_safepoint_check_flag); 556 Method::set_code(mh, mh->aot_code()); 557 } 558 } 559 return; 560 } 561 562 if (!CompilationModeFlag::disable_intermediate()) { 563 // Check if the method can be compiled. If it cannot be compiled with C1, continue profiling 564 // in the interpreter and then compile with C2 (the transition function will request that, 565 // see common() ). If the method cannot be compiled with C2 but still can with C1, compile it with 566 // pure C1. 567 if ((bci == InvocationEntryBci && !can_be_compiled(mh, level))) { 568 if (level == CompLevel_full_optimization && can_be_compiled(mh, CompLevel_simple)) { 569 compile(mh, bci, CompLevel_simple, thread); 570 } 571 return; 572 } 573 if ((bci != InvocationEntryBci && !can_be_osr_compiled(mh, level))) { 574 if (level == CompLevel_full_optimization && can_be_osr_compiled(mh, CompLevel_simple)) { 575 nmethod* osr_nm = mh->lookup_osr_nmethod_for(bci, CompLevel_simple, false); 576 if (osr_nm != NULL && osr_nm->comp_level() > CompLevel_simple) { 577 // Invalidate the existing OSR nmethod so that a compile at CompLevel_simple is permitted. 578 osr_nm->make_not_entrant(); 579 } 580 compile(mh, bci, CompLevel_simple, thread); 581 } 582 return; 583 } 584 } 585 if (bci != InvocationEntryBci && mh->is_not_osr_compilable(level)) { 586 return; 587 } 588 if (!CompileBroker::compilation_is_in_queue(mh)) { 589 if (PrintTieredEvents) { 590 print_event(COMPILE, mh(), mh(), bci, level); 591 } 592 int hot_count = (bci == InvocationEntryBci) ? mh->invocation_count() : mh->backedge_count(); 593 update_rate(nanos_to_millis(os::javaTimeNanos()), mh()); 594 CompileBroker::compile_method(mh, bci, level, mh, hot_count, CompileTask::Reason_Tiered, thread); 595 } 596 } 597 598 // update_rate() is called from select_task() while holding a compile queue lock. 599 void TieredThresholdPolicy::update_rate(jlong t, Method* m) { 600 // Skip update if counters are absent. 601 // Can't allocate them since we are holding compile queue lock. 602 if (m->method_counters() == NULL) return; 603 604 if (is_old(m)) { 605 // We don't remove old methods from the queue, 606 // so we can just zero the rate. 607 m->set_rate(0); 608 return; 609 } 610 611 // We don't update the rate if we've just came out of a safepoint. 612 // delta_s is the time since last safepoint in milliseconds. 613 jlong delta_s = t - SafepointTracing::end_of_last_safepoint_ms(); 614 jlong delta_t = t - (m->prev_time() != 0 ? m->prev_time() : start_time()); // milliseconds since the last measurement 615 // How many events were there since the last time? 616 int event_count = m->invocation_count() + m->backedge_count(); 617 int delta_e = event_count - m->prev_event_count(); 618 619 // We should be running for at least 1ms. 620 if (delta_s >= TieredRateUpdateMinTime) { 621 // And we must've taken the previous point at least 1ms before. 622 if (delta_t >= TieredRateUpdateMinTime && delta_e > 0) { 623 m->set_prev_time(t); 624 m->set_prev_event_count(event_count); 625 m->set_rate((float)delta_e / (float)delta_t); // Rate is events per millisecond 626 } else { 627 if (delta_t > TieredRateUpdateMaxTime && delta_e == 0) { 628 // If nothing happened for 25ms, zero the rate. Don't modify prev values. 629 m->set_rate(0); 630 } 631 } 632 } 633 } 634 635 // Check if this method has been stale for a given number of milliseconds. 636 // See select_task(). 637 bool TieredThresholdPolicy::is_stale(jlong t, jlong timeout, Method* m) { 638 jlong delta_s = t - SafepointTracing::end_of_last_safepoint_ms(); 639 jlong delta_t = t - m->prev_time(); 640 if (delta_t > timeout && delta_s > timeout) { 641 int event_count = m->invocation_count() + m->backedge_count(); 642 int delta_e = event_count - m->prev_event_count(); 643 // Return true if there were no events. 644 return delta_e == 0; 645 } 646 return false; 647 } 648 649 // We don't remove old methods from the compile queue even if they have 650 // very low activity. See select_task(). 651 bool TieredThresholdPolicy::is_old(Method* method) { 652 return method->invocation_count() > 50000 || method->backedge_count() > 500000; 653 } 654 655 double TieredThresholdPolicy::weight(Method* method) { 656 return (double)(method->rate() + 1) * 657 (method->invocation_count() + 1) * (method->backedge_count() + 1); 658 } 659 660 // Apply heuristics and return true if x should be compiled before y 661 bool TieredThresholdPolicy::compare_methods(Method* x, Method* y) { 662 if (x->highest_comp_level() > y->highest_comp_level()) { 663 // recompilation after deopt 664 return true; 665 } else 666 if (x->highest_comp_level() == y->highest_comp_level()) { 667 if (weight(x) > weight(y)) { 668 return true; 669 } 670 } 671 return false; 672 } 673 674 // Is method profiled enough? 675 bool TieredThresholdPolicy::is_method_profiled(const methodHandle& method) { 676 MethodData* mdo = method->method_data(); 677 if (mdo != NULL) { 678 int i = mdo->invocation_count_delta(); 679 int b = mdo->backedge_count_delta(); 680 return call_predicate_helper(method, CompilationModeFlag::disable_intermediate() ? CompLevel_none : CompLevel_full_profile, i, b, 1); 681 } 682 return false; 683 } 684 685 double TieredThresholdPolicy::threshold_scale(CompLevel level, int feedback_k) { 686 int comp_count = compiler_count(level); 687 if (comp_count > 0) { 688 double queue_size = CompileBroker::queue_size(level); 689 double k = queue_size / (feedback_k * comp_count) + 1; 690 691 // Increase C1 compile threshold when the code cache is filled more 692 // than specified by IncreaseFirstTierCompileThresholdAt percentage. 693 // The main intention is to keep enough free space for C2 compiled code 694 // to achieve peak performance if the code cache is under stress. 695 if (!CompilationModeFlag::disable_intermediate() && TieredStopAtLevel == CompLevel_full_optimization && level != CompLevel_full_optimization) { 696 double current_reverse_free_ratio = CodeCache::reverse_free_ratio(CodeCache::get_code_blob_type(level)); 697 if (current_reverse_free_ratio > _increase_threshold_at_ratio) { 698 k *= exp(current_reverse_free_ratio - _increase_threshold_at_ratio); 699 } 700 } 701 return k; 702 } 703 return 1; 704 } 705 706 // Call and loop predicates determine whether a transition to a higher 707 // compilation level should be performed (pointers to predicate functions 708 // are passed to common()). 709 // Tier?LoadFeedback is basically a coefficient that determines of 710 // how many methods per compiler thread can be in the queue before 711 // the threshold values double. 712 bool TieredThresholdPolicy::loop_predicate(int i, int b, CompLevel cur_level, const methodHandle& method) { 713 double k = 1; 714 switch(cur_level) { 715 case CompLevel_aot: { 716 k = CompilationModeFlag::disable_intermediate() ? 1 : threshold_scale(CompLevel_full_profile, Tier3LoadFeedback); 717 break; 718 } 719 case CompLevel_none: { 720 if (CompilationModeFlag::disable_intermediate()) { 721 k = threshold_scale(CompLevel_full_optimization, Tier4LoadFeedback); 722 break; 723 } 724 } 725 // Fall through 726 case CompLevel_limited_profile: { 727 k = threshold_scale(CompLevel_full_profile, Tier3LoadFeedback); 728 break; 729 } 730 case CompLevel_full_profile: { 731 k = threshold_scale(CompLevel_full_optimization, Tier4LoadFeedback); 732 break; 733 } 734 default: 735 return true; 736 } 737 return loop_predicate_helper(method, cur_level, i, b, k); 738 } 739 740 bool TieredThresholdPolicy::call_predicate(int i, int b, CompLevel cur_level, const methodHandle& method) { 741 double k = 1; 742 switch(cur_level) { 743 case CompLevel_aot: { 744 k = CompilationModeFlag::disable_intermediate() ? 1 : threshold_scale(CompLevel_full_profile, Tier3LoadFeedback); 745 break; 746 } 747 case CompLevel_none: { 748 if (CompilationModeFlag::disable_intermediate()) { 749 k = threshold_scale(CompLevel_full_optimization, Tier4LoadFeedback); 750 break; 751 } 752 } 753 // Fall through 754 case CompLevel_limited_profile: { 755 k = threshold_scale(CompLevel_full_profile, Tier3LoadFeedback); 756 break; 757 } 758 case CompLevel_full_profile: { 759 k = threshold_scale(CompLevel_full_optimization, Tier4LoadFeedback); 760 break; 761 } 762 default: 763 return true; 764 } 765 return call_predicate_helper(method, cur_level, i, b, k); 766 } 767 768 // Determine is a method is mature. 769 bool TieredThresholdPolicy::is_mature(Method* method) { 770 methodHandle mh(Thread::current(), method); 771 if (is_trivial(method) || force_comp_at_level_simple(mh)) return true; 772 MethodData* mdo = method->method_data(); 773 if (mdo != NULL) { 774 int i = mdo->invocation_count(); 775 int b = mdo->backedge_count(); 776 double k = ProfileMaturityPercentage / 100.0; 777 CompLevel main_profile_level = CompilationModeFlag::disable_intermediate() ? CompLevel_none : CompLevel_full_profile; 778 return call_predicate_helper(mh, main_profile_level, i, b, k) || loop_predicate_helper(mh, main_profile_level, i, b, k); 779 } 780 return false; 781 } 782 783 // If a method is old enough and is still in the interpreter we would want to 784 // start profiling without waiting for the compiled method to arrive. 785 // We also take the load on compilers into the account. 786 bool TieredThresholdPolicy::should_create_mdo(const methodHandle& method, CompLevel cur_level) { 787 if (cur_level != CompLevel_none || force_comp_at_level_simple(method)) { 788 return false; 789 } 790 int i = method->invocation_count(); 791 int b = method->backedge_count(); 792 double k = Tier0ProfilingStartPercentage / 100.0; 793 794 // If the top level compiler is not keeping up, delay profiling. 795 if (CompileBroker::queue_size(CompLevel_full_optimization) <= (CompilationModeFlag::disable_intermediate() ? Tier0Delay : Tier3DelayOn) * compiler_count(CompLevel_full_optimization)) { 796 return call_predicate_helper(method, CompLevel_none, i, b, k) || loop_predicate_helper(method, CompLevel_none, i, b, k); 797 } 798 return false; 799 } 800 801 // Inlining control: if we're compiling a profiled method with C1 and the callee 802 // is known to have OSRed in a C2 version, don't inline it. 803 bool TieredThresholdPolicy::should_not_inline(ciEnv* env, ciMethod* callee) { 804 CompLevel comp_level = (CompLevel)env->comp_level(); 805 if (comp_level == CompLevel_full_profile || 806 comp_level == CompLevel_limited_profile) { 807 return callee->highest_osr_comp_level() == CompLevel_full_optimization; 808 } 809 return false; 810 } 811 812 // Create MDO if necessary. 813 void TieredThresholdPolicy::create_mdo(const methodHandle& mh, JavaThread* THREAD) { 814 if (mh->is_native() || 815 mh->is_abstract() || 816 mh->is_accessor() || 817 mh->is_constant_getter()) { 818 return; 819 } 820 if (mh->method_data() == NULL) { 821 Method::build_interpreter_method_data(mh, CHECK_AND_CLEAR); 822 } 823 } 824 825 826 /* 827 * Method states: 828 * 0 - interpreter (CompLevel_none) 829 * 1 - pure C1 (CompLevel_simple) 830 * 2 - C1 with invocation and backedge counting (CompLevel_limited_profile) 831 * 3 - C1 with full profiling (CompLevel_full_profile) 832 * 4 - C2 or Graal (CompLevel_full_optimization) 833 * 834 * Common state transition patterns: 835 * a. 0 -> 3 -> 4. 836 * The most common path. But note that even in this straightforward case 837 * profiling can start at level 0 and finish at level 3. 838 * 839 * b. 0 -> 2 -> 3 -> 4. 840 * This case occurs when the load on C2 is deemed too high. So, instead of transitioning 841 * into state 3 directly and over-profiling while a method is in the C2 queue we transition to 842 * level 2 and wait until the load on C2 decreases. This path is disabled for OSRs. 843 * 844 * c. 0 -> (3->2) -> 4. 845 * In this case we enqueue a method for compilation at level 3, but the C1 queue is long enough 846 * to enable the profiling to fully occur at level 0. In this case we change the compilation level 847 * of the method to 2 while the request is still in-queue, because it'll allow it to run much faster 848 * without full profiling while c2 is compiling. 849 * 850 * d. 0 -> 3 -> 1 or 0 -> 2 -> 1. 851 * After a method was once compiled with C1 it can be identified as trivial and be compiled to 852 * level 1. These transition can also occur if a method can't be compiled with C2 but can with C1. 853 * 854 * e. 0 -> 4. 855 * This can happen if a method fails C1 compilation (it will still be profiled in the interpreter) 856 * or because of a deopt that didn't require reprofiling (compilation won't happen in this case because 857 * the compiled version already exists). 858 * 859 * Note that since state 0 can be reached from any other state via deoptimization different loops 860 * are possible. 861 * 862 */ 863 864 // Common transition function. Given a predicate determines if a method should transition to another level. 865 CompLevel TieredThresholdPolicy::common(Predicate p, const methodHandle& method, CompLevel cur_level, bool disable_feedback) { 866 CompLevel next_level = cur_level; 867 int i = method->invocation_count(); 868 int b = method->backedge_count(); 869 870 if (force_comp_at_level_simple(method)) { 871 next_level = CompLevel_simple; 872 } else { 873 if (!CompilationModeFlag::disable_intermediate() && is_trivial(method())) { 874 next_level = CompLevel_simple; 875 } else { 876 switch(cur_level) { 877 default: break; 878 case CompLevel_aot: 879 if (CompilationModeFlag::disable_intermediate()) { 880 if (disable_feedback || (CompileBroker::queue_size(CompLevel_full_optimization) <= 881 Tier0Delay * compiler_count(CompLevel_full_optimization) && 882 (this->*p)(i, b, cur_level, method))) { 883 next_level = CompLevel_none; 884 } 885 } else { 886 // If we were at full profile level, would we switch to full opt? 887 if (common(p, method, CompLevel_full_profile, disable_feedback) == CompLevel_full_optimization) { 888 next_level = CompLevel_full_optimization; 889 } else if (disable_feedback || (CompileBroker::queue_size(CompLevel_full_optimization) <= 890 Tier3DelayOff * compiler_count(CompLevel_full_optimization) && 891 (this->*p)(i, b, cur_level, method))) { 892 next_level = CompLevel_full_profile; 893 } 894 } 895 break; 896 case CompLevel_none: 897 if (CompilationModeFlag::disable_intermediate()) { 898 MethodData* mdo = method->method_data(); 899 if (mdo != NULL) { 900 // If mdo exists that means we are in a normal profiling mode. 901 int mdo_i = mdo->invocation_count_delta(); 902 int mdo_b = mdo->backedge_count_delta(); 903 if ((this->*p)(mdo_i, mdo_b, cur_level, method)) { 904 next_level = CompLevel_full_optimization; 905 } 906 } 907 } else { 908 // If we were at full profile level, would we switch to full opt? 909 if (common(p, method, CompLevel_full_profile, disable_feedback) == CompLevel_full_optimization) { 910 next_level = CompLevel_full_optimization; 911 } else if ((this->*p)(i, b, cur_level, method)) { 912 #if INCLUDE_JVMCI 913 if (EnableJVMCI && UseJVMCICompiler) { 914 // Since JVMCI takes a while to warm up, its queue inevitably backs up during 915 // early VM execution. As of 2014-06-13, JVMCI's inliner assumes that the root 916 // compilation method and all potential inlinees have mature profiles (which 917 // includes type profiling). If it sees immature profiles, JVMCI's inliner 918 // can perform pathologically bad (e.g., causing OutOfMemoryErrors due to 919 // exploring/inlining too many graphs). Since a rewrite of the inliner is 920 // in progress, we simply disable the dialing back heuristic for now and will 921 // revisit this decision once the new inliner is completed. 922 next_level = CompLevel_full_profile; 923 } else 924 #endif 925 { 926 // C1-generated fully profiled code is about 30% slower than the limited profile 927 // code that has only invocation and backedge counters. The observation is that 928 // if C2 queue is large enough we can spend too much time in the fully profiled code 929 // while waiting for C2 to pick the method from the queue. To alleviate this problem 930 // we introduce a feedback on the C2 queue size. If the C2 queue is sufficiently long 931 // we choose to compile a limited profiled version and then recompile with full profiling 932 // when the load on C2 goes down. 933 if (!disable_feedback && CompileBroker::queue_size(CompLevel_full_optimization) > 934 Tier3DelayOn * compiler_count(CompLevel_full_optimization)) { 935 next_level = CompLevel_limited_profile; 936 } else { 937 next_level = CompLevel_full_profile; 938 } 939 } 940 } 941 } 942 break; 943 case CompLevel_limited_profile: 944 if (is_method_profiled(method)) { 945 // Special case: we got here because this method was fully profiled in the interpreter. 946 next_level = CompLevel_full_optimization; 947 } else { 948 MethodData* mdo = method->method_data(); 949 if (mdo != NULL) { 950 if (mdo->would_profile()) { 951 if (disable_feedback || (CompileBroker::queue_size(CompLevel_full_optimization) <= 952 Tier3DelayOff * compiler_count(CompLevel_full_optimization) && 953 (this->*p)(i, b, cur_level, method))) { 954 next_level = CompLevel_full_profile; 955 } 956 } else { 957 next_level = CompLevel_full_optimization; 958 } 959 } else { 960 // If there is no MDO we need to profile 961 if (disable_feedback || (CompileBroker::queue_size(CompLevel_full_optimization) <= 962 Tier3DelayOff * compiler_count(CompLevel_full_optimization) && 963 (this->*p)(i, b, cur_level, method))) { 964 next_level = CompLevel_full_profile; 965 } 966 } 967 } 968 break; 969 case CompLevel_full_profile: 970 { 971 MethodData* mdo = method->method_data(); 972 if (mdo != NULL) { 973 if (mdo->would_profile()) { 974 int mdo_i = mdo->invocation_count_delta(); 975 int mdo_b = mdo->backedge_count_delta(); 976 if ((this->*p)(mdo_i, mdo_b, cur_level, method)) { 977 next_level = CompLevel_full_optimization; 978 } 979 } else { 980 next_level = CompLevel_full_optimization; 981 } 982 } 983 } 984 break; 985 } 986 } 987 } 988 return limit_level(next_level); 989 } 990 991 992 993 // Determine if a method should be compiled with a normal entry point at a different level. 994 CompLevel TieredThresholdPolicy::call_event(const methodHandle& method, CompLevel cur_level, JavaThread* thread) { 995 CompLevel osr_level = MIN2((CompLevel) method->highest_osr_comp_level(), 996 common(&TieredThresholdPolicy::loop_predicate, method, cur_level, true)); 997 CompLevel next_level = common(&TieredThresholdPolicy::call_predicate, method, cur_level); 998 999 // If OSR method level is greater than the regular method level, the levels should be 1000 // equalized by raising the regular method level in order to avoid OSRs during each 1001 // invocation of the method. 1002 if (osr_level == CompLevel_full_optimization && cur_level == CompLevel_full_profile) { 1003 MethodData* mdo = method->method_data(); 1004 guarantee(mdo != NULL, "MDO should not be NULL"); 1005 if (mdo->invocation_count() >= 1) { 1006 next_level = CompLevel_full_optimization; 1007 } 1008 } else { 1009 next_level = MAX2(osr_level, next_level); 1010 } 1011 return next_level; 1012 } 1013 1014 // Determine if we should do an OSR compilation of a given method. 1015 CompLevel TieredThresholdPolicy::loop_event(const methodHandle& method, CompLevel cur_level, JavaThread* thread) { 1016 CompLevel next_level = common(&TieredThresholdPolicy::loop_predicate, method, cur_level, true); 1017 if (cur_level == CompLevel_none) { 1018 // If there is a live OSR method that means that we deopted to the interpreter 1019 // for the transition. 1020 CompLevel osr_level = MIN2((CompLevel)method->highest_osr_comp_level(), next_level); 1021 if (osr_level > CompLevel_none) { 1022 return osr_level; 1023 } 1024 } 1025 return next_level; 1026 } 1027 1028 bool TieredThresholdPolicy::maybe_switch_to_aot(const methodHandle& mh, CompLevel cur_level, CompLevel next_level, JavaThread* thread) { 1029 if (UseAOT) { 1030 if (cur_level == CompLevel_full_profile || cur_level == CompLevel_none) { 1031 // If the current level is full profile or interpreter and we're switching to any other level, 1032 // activate the AOT code back first so that we won't waste time overprofiling. 1033 compile(mh, InvocationEntryBci, CompLevel_aot, thread); 1034 // Fall through for JIT compilation. 1035 } 1036 if (next_level == CompLevel_limited_profile && cur_level != CompLevel_aot && mh->has_aot_code()) { 1037 // If the next level is limited profile, use the aot code (if there is any), 1038 // since it's essentially the same thing. 1039 compile(mh, InvocationEntryBci, CompLevel_aot, thread); 1040 // Not need to JIT, we're done. 1041 return true; 1042 } 1043 } 1044 return false; 1045 } 1046 1047 1048 // Handle the invocation event. 1049 void TieredThresholdPolicy::method_invocation_event(const methodHandle& mh, const methodHandle& imh, 1050 CompLevel level, CompiledMethod* nm, JavaThread* thread) { 1051 if (should_create_mdo(mh, level)) { 1052 create_mdo(mh, thread); 1053 } 1054 CompLevel next_level = call_event(mh, level, thread); 1055 if (next_level != level) { 1056 if (maybe_switch_to_aot(mh, level, next_level, thread)) { 1057 // No JITting necessary 1058 return; 1059 } 1060 if (is_compilation_enabled() && !CompileBroker::compilation_is_in_queue(mh)) { 1061 compile(mh, InvocationEntryBci, next_level, thread); 1062 } 1063 } 1064 } 1065 1066 // Handle the back branch event. Notice that we can compile the method 1067 // with a regular entry from here. 1068 void TieredThresholdPolicy::method_back_branch_event(const methodHandle& mh, const methodHandle& imh, 1069 int bci, CompLevel level, CompiledMethod* nm, JavaThread* thread) { 1070 if (should_create_mdo(mh, level)) { 1071 create_mdo(mh, thread); 1072 } 1073 // Check if MDO should be created for the inlined method 1074 if (should_create_mdo(imh, level)) { 1075 create_mdo(imh, thread); 1076 } 1077 1078 if (is_compilation_enabled()) { 1079 CompLevel next_osr_level = loop_event(imh, level, thread); 1080 CompLevel max_osr_level = (CompLevel)imh->highest_osr_comp_level(); 1081 // At the very least compile the OSR version 1082 if (!CompileBroker::compilation_is_in_queue(imh) && (next_osr_level != level)) { 1083 compile(imh, bci, next_osr_level, thread); 1084 } 1085 1086 // Use loop event as an opportunity to also check if there's been 1087 // enough calls. 1088 CompLevel cur_level, next_level; 1089 if (mh() != imh()) { // If there is an enclosing method 1090 if (level == CompLevel_aot) { 1091 // Recompile the enclosing method to prevent infinite OSRs. Stay at AOT level while it's compiling. 1092 if (max_osr_level != CompLevel_none && !CompileBroker::compilation_is_in_queue(mh)) { 1093 CompLevel enclosing_level = limit_level(CompLevel_full_profile); 1094 compile(mh, InvocationEntryBci, enclosing_level, thread); 1095 } 1096 } else { 1097 // Current loop event level is not AOT 1098 guarantee(nm != NULL, "Should have nmethod here"); 1099 cur_level = comp_level(mh()); 1100 next_level = call_event(mh, cur_level, thread); 1101 1102 if (max_osr_level == CompLevel_full_optimization) { 1103 // The inlinee OSRed to full opt, we need to modify the enclosing method to avoid deopts 1104 bool make_not_entrant = false; 1105 if (nm->is_osr_method()) { 1106 // This is an osr method, just make it not entrant and recompile later if needed 1107 make_not_entrant = true; 1108 } else { 1109 if (next_level != CompLevel_full_optimization) { 1110 // next_level is not full opt, so we need to recompile the 1111 // enclosing method without the inlinee 1112 cur_level = CompLevel_none; 1113 make_not_entrant = true; 1114 } 1115 } 1116 if (make_not_entrant) { 1117 if (PrintTieredEvents) { 1118 int osr_bci = nm->is_osr_method() ? nm->osr_entry_bci() : InvocationEntryBci; 1119 print_event(MAKE_NOT_ENTRANT, mh(), mh(), osr_bci, level); 1120 } 1121 nm->make_not_entrant(); 1122 } 1123 } 1124 // Fix up next_level if necessary to avoid deopts 1125 if (next_level == CompLevel_limited_profile && max_osr_level == CompLevel_full_profile) { 1126 next_level = CompLevel_full_profile; 1127 } 1128 if (cur_level != next_level) { 1129 if (!maybe_switch_to_aot(mh, cur_level, next_level, thread) && !CompileBroker::compilation_is_in_queue(mh)) { 1130 compile(mh, InvocationEntryBci, next_level, thread); 1131 } 1132 } 1133 } 1134 } else { 1135 cur_level = comp_level(mh()); 1136 next_level = call_event(mh, cur_level, thread); 1137 if (next_level != cur_level) { 1138 if (!maybe_switch_to_aot(mh, cur_level, next_level, thread) && !CompileBroker::compilation_is_in_queue(mh)) { 1139 compile(mh, InvocationEntryBci, next_level, thread); 1140 } 1141 } 1142 } 1143 } 1144 } 1145 1146 #endif