1 /* 2 * Copyright (c) 1997, 2024, Oracle and/or its affiliates. All rights reserved. 3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. 4 * 5 * This code is free software; you can redistribute it and/or modify it 6 * under the terms of the GNU General Public License version 2 only, as 7 * published by the Free Software Foundation. 8 * 9 * This code is distributed in the hope that it will be useful, but WITHOUT 10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 12 * version 2 for more details (a copy is included in the LICENSE file that 13 * accompanied this code). 14 * 15 * You should have received a copy of the GNU General Public License version 16 * 2 along with this work; if not, write to the Free Software Foundation, 17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. 18 * 19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA 20 * or visit www.oracle.com if you need additional information or have any 21 * questions. 22 * 23 */ 24 25 #ifndef SHARE_RUNTIME_GLOBALS_HPP 26 #define SHARE_RUNTIME_GLOBALS_HPP 27 28 #include "compiler/compiler_globals_pd.hpp" 29 #include "runtime/globals_shared.hpp" 30 #include "utilities/align.hpp" 31 #include "utilities/globalDefinitions.hpp" 32 #include "utilities/macros.hpp" 33 #include CPU_HEADER(globals) 34 #include OS_HEADER(globals) 35 #include OS_CPU_HEADER(globals) 36 37 // develop flags are settable / visible only during development and are constant in the PRODUCT version 38 // product flags are always settable / visible 39 // notproduct flags are settable / visible only during development and are not declared in the PRODUCT version 40 // develop_pd/product_pd flags are the same as develop/product, except that their default values 41 // are specified in platform-dependent header files. 42 43 // Flags must be declared with the following number of parameters: 44 // non-pd flags: 45 // (type, name, default_value, doc), or 46 // (type, name, default_value, extra_attrs, doc) 47 // pd flags: 48 // (type, name, doc), or 49 // (type, name, extra_attrs, doc) 50 51 // A flag must be declared with one of the following types: 52 // bool, int, uint, intx, uintx, size_t, ccstr, ccstrlist, double, or uint64_t. 53 // The type "ccstr" and "ccstrlist" are an alias for "const char*" and is used 54 // only in this file, because the macrology requires single-token type names. 55 56 // The optional extra_attrs parameter may have one of the following values: 57 // DIAGNOSTIC, EXPERIMENTAL, or MANAGEABLE. Currently extra_attrs can be used 58 // only with product/product_pd flags. 59 // 60 // DIAGNOSTIC options are not meant for VM tuning or for product modes. 61 // They are to be used for VM quality assurance or field diagnosis 62 // of VM bugs. They are hidden so that users will not be encouraged to 63 // try them as if they were VM ordinary execution options. However, they 64 // are available in the product version of the VM. Under instruction 65 // from support engineers, VM customers can turn them on to collect 66 // diagnostic information about VM problems. To use a VM diagnostic 67 // option, you must first specify +UnlockDiagnosticVMOptions. 68 // (This master switch also affects the behavior of -Xprintflags.) 69 // 70 // EXPERIMENTAL flags are in support of features that may not be 71 // an officially supported part of a product, but may be available 72 // for experimenting with. They could, for example, be performance 73 // features that may not have undergone full or rigorous QA, but which may 74 // help performance in some cases and released for experimentation 75 // by the community of users and developers. This flag also allows one to 76 // be able to build a fully supported product that nonetheless also 77 // ships with some unsupported, lightly tested, experimental features. 78 // Refer to the documentation of any products using this code for details 79 // on support and fitness for production. 80 // Like the UnlockDiagnosticVMOptions flag above, there is a corresponding 81 // UnlockExperimentalVMOptions flag, which allows the control and 82 // modification of the experimental flags. 83 // 84 // Nota bene: neither diagnostic nor experimental options should be used casually, 85 // Refer to the documentation of any products using this code for details. 86 // 87 // MANAGEABLE flags are writeable external product flags. 88 // They are dynamically writeable through the JDK management interface 89 // (com.sun.management.HotSpotDiagnosticMXBean API) and also through JConsole. 90 // These flags are external exported interface (see CSR). The list of 91 // manageable flags can be queried programmatically through the management 92 // interface. 93 // 94 // A flag can be made as "manageable" only if 95 // - the flag is defined in a CSR request as an external exported interface. 96 // - the VM implementation supports dynamic setting of the flag. 97 // This implies that the VM must *always* query the flag variable 98 // and not reuse state related to the flag state at any given time. 99 // - you want the flag to be queried programmatically by the customers. 100 // 101 102 // 103 // range is a macro that will expand to min and max arguments for range 104 // checking code if provided - see jvmFlagLimit.hpp 105 // 106 // constraint is a macro that will expand to custom function call 107 // for constraint checking if provided - see jvmFlagLimit.hpp 108 109 // Default and minimum StringTable and SymbolTable size values 110 // Must be powers of 2 111 const size_t defaultStringTableSize = NOT_LP64(1024) LP64_ONLY(65536); 112 const size_t minimumStringTableSize = 128; 113 const size_t defaultSymbolTableSize = 32768; // 2^15 114 const size_t minimumSymbolTableSize = 1024; 115 116 #ifdef _LP64 117 #define LP64_RUNTIME_FLAGS(develop, \ 118 develop_pd, \ 119 product, \ 120 product_pd, \ 121 notproduct, \ 122 range, \ 123 constraint) \ 124 \ 125 product(bool, UseCompressedOops, false, \ 126 "Use 32-bit object references in 64-bit VM. " \ 127 "lp64_product means flag is always constant in 32 bit VM") \ 128 \ 129 product(bool, UseCompressedClassPointers, true, \ 130 "Use 32-bit class pointers in 64-bit VM. " \ 131 "lp64_product means flag is always constant in 32 bit VM") \ 132 \ 133 product(int, ObjectAlignmentInBytes, 8, \ 134 "Default object alignment in bytes, 8 is minimum") \ 135 range(8, 256) \ 136 constraint(ObjectAlignmentInBytesConstraintFunc, AtParse) 137 138 #else 139 // !_LP64 140 141 #define LP64_RUNTIME_FLAGS(develop, \ 142 develop_pd, \ 143 product, \ 144 product_pd, \ 145 notproduct, \ 146 range, \ 147 constraint) 148 const bool UseCompressedOops = false; 149 const bool UseCompressedClassPointers = false; 150 const int ObjectAlignmentInBytes = 8; 151 152 #endif // _LP64 153 154 #define RUNTIME_FLAGS(develop, \ 155 develop_pd, \ 156 product, \ 157 product_pd, \ 158 notproduct, \ 159 range, \ 160 constraint) \ 161 \ 162 notproduct(bool, CheckCompressedOops, true, \ 163 "Generate checks in encoding/decoding code in debug VM") \ 164 \ 165 product(uintx, HeapSearchSteps, 3 PPC64_ONLY(+17), \ 166 "Heap allocation steps through preferred address regions to find" \ 167 " where it can allocate the heap. Number of steps to take per " \ 168 "region.") \ 169 range(1, max_uintx) \ 170 \ 171 product(uint, HandshakeTimeout, 0, DIAGNOSTIC, \ 172 "If nonzero set a timeout in milliseconds for handshakes") \ 173 \ 174 product(bool, AlwaysSafeConstructors, false, EXPERIMENTAL, \ 175 "Force safe construction, as if all fields are final.") \ 176 \ 177 product(bool, UnlockDiagnosticVMOptions, trueInDebug, DIAGNOSTIC, \ 178 "Enable normal processing of flags relating to field diagnostics")\ 179 \ 180 product(bool, UnlockExperimentalVMOptions, false, EXPERIMENTAL, \ 181 "Enable normal processing of flags relating to experimental " \ 182 "features") \ 183 \ 184 product(bool, JavaMonitorsInStackTrace, true, \ 185 "Print information about Java monitor locks when the stacks are " \ 186 "dumped") \ 187 \ 188 product_pd(bool, UseLargePages, \ 189 "Use large page memory") \ 190 \ 191 product_pd(bool, UseLargePagesIndividualAllocation, \ 192 "Allocate large pages individually for better affinity") \ 193 \ 194 develop(bool, LargePagesIndividualAllocationInjectError, false, \ 195 "Fail large pages individual allocation") \ 196 \ 197 product(bool, UseNUMA, false, \ 198 "Use NUMA if available") \ 199 \ 200 product(bool, UseNUMAInterleaving, false, \ 201 "Interleave memory across NUMA nodes if available") \ 202 \ 203 product(size_t, NUMAInterleaveGranularity, 2*M, \ 204 "Granularity to use for NUMA interleaving on Windows OS") \ 205 constraint(NUMAInterleaveGranularityConstraintFunc, AtParse) \ 206 \ 207 product(uintx, NUMAChunkResizeWeight, 20, \ 208 "Percentage (0-100) used to weight the current sample when " \ 209 "computing exponentially decaying average for " \ 210 "AdaptiveNUMAChunkSizing") \ 211 range(0, 100) \ 212 \ 213 product(size_t, NUMASpaceResizeRate, 1*G, \ 214 "Do not reallocate more than this amount per collection") \ 215 range(0, max_uintx) \ 216 \ 217 product(bool, UseAdaptiveNUMAChunkSizing, true, \ 218 "Enable adaptive chunk sizing for NUMA") \ 219 \ 220 product(bool, NUMAStats, false, \ 221 "Print NUMA stats in detailed heap information") \ 222 \ 223 product(uintx, NUMAPageScanRate, 256, \ 224 "Maximum number of pages to include in the page scan procedure") \ 225 range(0, max_uintx) \ 226 \ 227 product(bool, UseAES, false, \ 228 "Control whether AES instructions are used when available") \ 229 \ 230 product(bool, UseFMA, false, \ 231 "Control whether FMA instructions are used when available") \ 232 \ 233 product(bool, UseSHA, false, \ 234 "Control whether SHA instructions are used when available") \ 235 \ 236 product(bool, UseGHASHIntrinsics, false, DIAGNOSTIC, \ 237 "Use intrinsics for GHASH versions of crypto") \ 238 \ 239 product(bool, UseBASE64Intrinsics, false, \ 240 "Use intrinsics for java.util.Base64") \ 241 \ 242 product(bool, UsePoly1305Intrinsics, false, DIAGNOSTIC, \ 243 "Use intrinsics for sun.security.util.math.intpoly") \ 244 \ 245 product(size_t, LargePageSizeInBytes, 0, \ 246 "Maximum large page size used (0 will use the default large " \ 247 "page size for the environment as the maximum)") \ 248 range(0, max_uintx) \ 249 \ 250 product(size_t, LargePageHeapSizeThreshold, 128*M, \ 251 "Use large pages if maximum heap is at least this big") \ 252 range(0, max_uintx) \ 253 \ 254 product(bool, ForceTimeHighResolution, false, \ 255 "Using high time resolution (for Win32 only)") \ 256 \ 257 develop(bool, TracePcPatching, false, \ 258 "Trace usage of frame::patch_pc") \ 259 \ 260 develop(bool, TraceRelocator, false, \ 261 "Trace the bytecode relocator") \ 262 \ 263 \ 264 product(bool, SafepointALot, false, DIAGNOSTIC, \ 265 "Generate a lot of safepoints. This works with " \ 266 "GuaranteedSafepointInterval") \ 267 \ 268 product(bool, HandshakeALot, false, DIAGNOSTIC, \ 269 "Generate a lot of handshakes. This works with " \ 270 "GuaranteedSafepointInterval") \ 271 \ 272 product_pd(bool, BackgroundCompilation, \ 273 "A thread requesting compilation is not blocked during " \ 274 "compilation") \ 275 \ 276 product(bool, MethodFlushing, true, \ 277 "Reclamation of compiled methods") \ 278 \ 279 develop(bool, VerifyStack, false, \ 280 "Verify stack of each thread when it is entering a runtime call") \ 281 \ 282 product(bool, ForceUnreachable, false, DIAGNOSTIC, \ 283 "Make all non code cache addresses to be unreachable by " \ 284 "forcing use of 64bit literal fixups") \ 285 \ 286 develop(bool, TraceDerivedPointers, false, \ 287 "Trace traversal of derived pointers on stack") \ 288 \ 289 notproduct(bool, TraceCodeBlobStacks, false, \ 290 "Trace stack-walk of codeblobs") \ 291 \ 292 notproduct(bool, PrintRewrites, false, \ 293 "Print methods that are being rewritten") \ 294 \ 295 product(bool, UseInlineCaches, true, \ 296 "Use Inline Caches for virtual calls ") \ 297 \ 298 product(size_t, InlineCacheBufferSize, 10*K, EXPERIMENTAL, \ 299 "InlineCacheBuffer size") \ 300 \ 301 product(bool, InlineArrayCopy, true, DIAGNOSTIC, \ 302 "Inline arraycopy native that is known to be part of " \ 303 "base library DLL") \ 304 \ 305 product(bool, InlineObjectHash, true, DIAGNOSTIC, \ 306 "Inline Object::hashCode() native that is known to be part " \ 307 "of base library DLL") \ 308 \ 309 product(bool, InlineNatives, true, DIAGNOSTIC, \ 310 "Inline natives that are known to be part of base library DLL") \ 311 \ 312 product(bool, InlineMathNatives, true, DIAGNOSTIC, \ 313 "Inline SinD, CosD, etc.") \ 314 \ 315 product(bool, InlineClassNatives, true, DIAGNOSTIC, \ 316 "Inline Class.isInstance, etc") \ 317 \ 318 product(bool, InlineThreadNatives, true, DIAGNOSTIC, \ 319 "Inline Thread.currentThread, etc") \ 320 \ 321 product(bool, InlineUnsafeOps, true, DIAGNOSTIC, \ 322 "Inline memory ops (native methods) from Unsafe") \ 323 \ 324 product(bool, UseAESIntrinsics, false, DIAGNOSTIC, \ 325 "Use intrinsics for AES versions of crypto") \ 326 \ 327 product(bool, UseAESCTRIntrinsics, false, DIAGNOSTIC, \ 328 "Use intrinsics for the paralleled version of AES/CTR crypto") \ 329 \ 330 product(bool, UseChaCha20Intrinsics, false, DIAGNOSTIC, \ 331 "Use intrinsics for the vectorized version of ChaCha20") \ 332 \ 333 product(bool, UseMD5Intrinsics, false, DIAGNOSTIC, \ 334 "Use intrinsics for MD5 crypto hash function") \ 335 \ 336 product(bool, UseSHA1Intrinsics, false, DIAGNOSTIC, \ 337 "Use intrinsics for SHA-1 crypto hash function. " \ 338 "Requires that UseSHA is enabled.") \ 339 \ 340 product(bool, UseSHA256Intrinsics, false, DIAGNOSTIC, \ 341 "Use intrinsics for SHA-224 and SHA-256 crypto hash functions. " \ 342 "Requires that UseSHA is enabled.") \ 343 \ 344 product(bool, UseSHA512Intrinsics, false, DIAGNOSTIC, \ 345 "Use intrinsics for SHA-384 and SHA-512 crypto hash functions. " \ 346 "Requires that UseSHA is enabled.") \ 347 \ 348 product(bool, UseSHA3Intrinsics, false, DIAGNOSTIC, \ 349 "Use intrinsics for SHA3 crypto hash function. " \ 350 "Requires that UseSHA is enabled.") \ 351 \ 352 product(bool, UseCRC32Intrinsics, false, DIAGNOSTIC, \ 353 "use intrinsics for java.util.zip.CRC32") \ 354 \ 355 product(bool, UseCRC32CIntrinsics, false, DIAGNOSTIC, \ 356 "use intrinsics for java.util.zip.CRC32C") \ 357 \ 358 product(bool, UseAdler32Intrinsics, false, DIAGNOSTIC, \ 359 "use intrinsics for java.util.zip.Adler32") \ 360 \ 361 product(bool, UseVectorizedMismatchIntrinsic, false, DIAGNOSTIC, \ 362 "Enables intrinsification of ArraysSupport.vectorizedMismatch()") \ 363 \ 364 product(bool, UseVectorizedHashCodeIntrinsic, false, DIAGNOSTIC, \ 365 "Enables intrinsification of ArraysSupport.vectorizedHashCode()") \ 366 \ 367 product(bool, UseCopySignIntrinsic, false, DIAGNOSTIC, \ 368 "Enables intrinsification of Math.copySign") \ 369 \ 370 product(bool, UseSignumIntrinsic, false, DIAGNOSTIC, \ 371 "Enables intrinsification of Math.signum") \ 372 \ 373 product_pd(bool, DelayCompilerStubsGeneration, DIAGNOSTIC, \ 374 "Use Compiler thread for compiler's stubs generation") \ 375 \ 376 product(ccstrlist, DisableIntrinsic, "", DIAGNOSTIC, \ 377 "do not expand intrinsics whose (internal) names appear here") \ 378 constraint(DisableIntrinsicConstraintFunc,AfterErgo) \ 379 \ 380 product(ccstrlist, ControlIntrinsic, "", DIAGNOSTIC, \ 381 "Control intrinsics using a list of +/- (internal) names, " \ 382 "separated by commas") \ 383 constraint(ControlIntrinsicConstraintFunc,AfterErgo) \ 384 \ 385 develop(bool, TraceCallFixup, false, \ 386 "Trace all call fixups") \ 387 \ 388 develop(bool, DeoptimizeALot, false, \ 389 "Deoptimize at every exit from the runtime system") \ 390 \ 391 notproduct(ccstrlist, DeoptimizeOnlyAt, "", \ 392 "A comma separated list of bcis to deoptimize at") \ 393 \ 394 develop(bool, DeoptimizeRandom, false, \ 395 "Deoptimize random frames on random exit from the runtime system")\ 396 \ 397 notproduct(bool, ZombieALot, false, \ 398 "Create non-entrant nmethods at exit from the runtime system") \ 399 \ 400 notproduct(bool, WalkStackALot, false, \ 401 "Trace stack (no print) at every exit from the runtime system") \ 402 \ 403 develop(bool, DeoptimizeObjectsALot, false, \ 404 "For testing purposes concurrent threads revert optimizations " \ 405 "based on escape analysis at intervals given with " \ 406 "DeoptimizeObjectsALotInterval=n. The thread count is given " \ 407 "with DeoptimizeObjectsALotThreadCountSingle and " \ 408 "DeoptimizeObjectsALotThreadCountAll.") \ 409 \ 410 develop(uint64_t, DeoptimizeObjectsALotInterval, 5, \ 411 "Interval for DeoptimizeObjectsALot.") \ 412 range(0, max_jlong) \ 413 \ 414 develop(int, DeoptimizeObjectsALotThreadCountSingle, 1, \ 415 "The number of threads that revert optimizations based on " \ 416 "escape analysis for a single thread if DeoptimizeObjectsALot " \ 417 "is enabled. The target thread is selected round robin." ) \ 418 range(0, max_jint) \ 419 \ 420 develop(int, DeoptimizeObjectsALotThreadCountAll, 1, \ 421 "The number of threads that revert optimizations based on " \ 422 "escape analysis for all threads if DeoptimizeObjectsALot " \ 423 "is enabled." ) \ 424 range(0, max_jint) \ 425 \ 426 notproduct(bool, VerifyLastFrame, false, \ 427 "Verify oops on last frame on entry to VM") \ 428 \ 429 product(bool, SafepointTimeout, false, \ 430 "Time out and warn or fail after SafepointTimeoutDelay " \ 431 "milliseconds if failed to reach safepoint") \ 432 \ 433 product(bool, AbortVMOnSafepointTimeout, false, DIAGNOSTIC, \ 434 "Abort upon failure to reach safepoint (see SafepointTimeout)") \ 435 \ 436 product(bool, AbortVMOnVMOperationTimeout, false, DIAGNOSTIC, \ 437 "Abort upon failure to complete VM operation promptly") \ 438 \ 439 product(intx, AbortVMOnVMOperationTimeoutDelay, 1000, DIAGNOSTIC, \ 440 "Delay in milliseconds for option AbortVMOnVMOperationTimeout") \ 441 range(0, max_intx) \ 442 \ 443 product(bool, MaxFDLimit, true, \ 444 "Bump the number of file descriptors to maximum (Unix only)") \ 445 \ 446 product(bool, LogEvents, true, DIAGNOSTIC, \ 447 "Enable the various ring buffer event logs") \ 448 \ 449 product(uintx, LogEventsBufferEntries, 20, DIAGNOSTIC, \ 450 "Number of ring buffer event logs") \ 451 range(1, NOT_LP64(1*K) LP64_ONLY(1*M)) \ 452 \ 453 product(bool, BytecodeVerificationRemote, true, DIAGNOSTIC, \ 454 "Enable the Java bytecode verifier for remote classes") \ 455 \ 456 product(bool, BytecodeVerificationLocal, false, DIAGNOSTIC, \ 457 "Enable the Java bytecode verifier for local classes") \ 458 \ 459 develop(bool, VerifyStackAtCalls, false, \ 460 "Verify that the stack pointer is unchanged after calls") \ 461 \ 462 develop(bool, TraceJavaAssertions, false, \ 463 "Trace java language assertions") \ 464 \ 465 notproduct(bool, VerifyCodeCache, false, \ 466 "Verify code cache on memory allocation/deallocation") \ 467 \ 468 develop(bool, ZapResourceArea, trueInDebug, \ 469 "Zap freed resource/arena space") \ 470 \ 471 notproduct(bool, ZapVMHandleArea, trueInDebug, \ 472 "Zap freed VM handle space") \ 473 \ 474 notproduct(bool, ZapStackSegments, trueInDebug, \ 475 "Zap allocated/freed stack segments") \ 476 \ 477 develop(bool, ZapUnusedHeapArea, trueInDebug, \ 478 "Zap unused heap space") \ 479 \ 480 develop(bool, CheckZapUnusedHeapArea, false, \ 481 "Check zapping of unused heap space") \ 482 \ 483 develop(bool, ZapFillerObjects, trueInDebug, \ 484 "Zap filler objects") \ 485 \ 486 product(bool, ExecutingUnitTests, false, \ 487 "Whether the JVM is running unit tests or not") \ 488 \ 489 develop(uint, ErrorHandlerTest, 0, \ 490 "If > 0, provokes an error after VM initialization; the value " \ 491 "determines which error to provoke. See controlled_crash() " \ 492 "in vmError.cpp.") \ 493 range(0, 17) \ 494 \ 495 develop(uint, TestCrashInErrorHandler, 0, \ 496 "If > 0, provokes an error inside VM error handler (a secondary " \ 497 "crash). see controlled_crash() in vmError.cpp") \ 498 range(0, 17) \ 499 \ 500 develop(bool, TestSafeFetchInErrorHandler, false , \ 501 "If true, tests SafeFetch inside error handler.") \ 502 \ 503 develop(bool, TestUnresponsiveErrorHandler, false, \ 504 "If true, simulates an unresponsive error handler.") \ 505 \ 506 develop(bool, Verbose, false, \ 507 "Print additional debugging information from other modes") \ 508 \ 509 develop(bool, PrintMiscellaneous, false, \ 510 "Print uncategorized debugging information (requires +Verbose)") \ 511 \ 512 develop(bool, WizardMode, false, \ 513 "Print much more debugging information") \ 514 \ 515 product(bool, ShowMessageBoxOnError, false, \ 516 "Keep process alive on VM fatal error") \ 517 \ 518 product(bool, CreateCoredumpOnCrash, true, \ 519 "Create core/mini dump on VM fatal error") \ 520 \ 521 product(uint64_t, ErrorLogTimeout, 2 * 60, \ 522 "Timeout, in seconds, to limit the time spent on writing an " \ 523 "error log in case of a crash.") \ 524 range(0, (uint64_t)max_jlong/1000) \ 525 \ 526 product(bool, ErrorLogSecondaryErrorDetails, false, DIAGNOSTIC, \ 527 "If enabled, show details on secondary crashes in the error log") \ 528 \ 529 develop(intx, TraceDwarfLevel, 0, \ 530 "Debug levels for the dwarf parser") \ 531 range(0, 4) \ 532 \ 533 product(bool, SuppressFatalErrorMessage, false, \ 534 "Report NO fatal error message (avoid deadlock)") \ 535 \ 536 product(ccstrlist, OnError, "", \ 537 "Run user-defined commands on fatal error; see VMError.cpp " \ 538 "for examples") \ 539 \ 540 product(ccstrlist, OnOutOfMemoryError, "", \ 541 "Run user-defined commands on first java.lang.OutOfMemoryError " \ 542 "thrown from JVM") \ 543 \ 544 product(bool, HeapDumpBeforeFullGC, false, MANAGEABLE, \ 545 "Dump heap to file before any major stop-the-world GC") \ 546 \ 547 product(bool, HeapDumpAfterFullGC, false, MANAGEABLE, \ 548 "Dump heap to file after any major stop-the-world GC") \ 549 \ 550 product(bool, HeapDumpOnOutOfMemoryError, false, MANAGEABLE, \ 551 "Dump heap to file when java.lang.OutOfMemoryError is thrown " \ 552 "from JVM") \ 553 \ 554 product(ccstr, HeapDumpPath, nullptr, MANAGEABLE, \ 555 "When HeapDumpOnOutOfMemoryError is on, the path (filename or " \ 556 "directory) of the dump file (defaults to java_pid<pid>.hprof " \ 557 "in the working directory)") \ 558 \ 559 product(intx, HeapDumpGzipLevel, 0, MANAGEABLE, \ 560 "When HeapDumpOnOutOfMemoryError is on, the gzip compression " \ 561 "level of the dump file. 0 (the default) disables gzip " \ 562 "compression. Otherwise the level must be between 1 and 9.") \ 563 range(0, 9) \ 564 \ 565 product(ccstr, NativeMemoryTracking, DEBUG_ONLY("summary") NOT_DEBUG("off"), \ 566 "Native memory tracking options") \ 567 \ 568 product(bool, PrintNMTStatistics, false, DIAGNOSTIC, \ 569 "Print native memory tracking summary data if it is on") \ 570 \ 571 product(bool, LogCompilation, false, DIAGNOSTIC, \ 572 "Log compilation activity in detail to LogFile") \ 573 \ 574 product(bool, PrintCompilation, false, \ 575 "Print compilations") \ 576 \ 577 product(intx, RepeatCompilation, 0, DIAGNOSTIC, \ 578 "Repeat compilation without installing code (number of times)") \ 579 range(0, max_jint) \ 580 \ 581 product(bool, PrintExtendedThreadInfo, false, \ 582 "Print more information in thread dump") \ 583 \ 584 product(intx, ScavengeRootsInCode, 2, DIAGNOSTIC, \ 585 "0: do not allow scavengable oops in the code cache; " \ 586 "1: allow scavenging from the code cache; " \ 587 "2: emit as many constants as the compiler can see") \ 588 range(0, 2) \ 589 \ 590 product(bool, AlwaysRestoreFPU, false, \ 591 "Restore the FPU control word after every JNI call (expensive)") \ 592 \ 593 product(bool, PrintCompilation2, false, DIAGNOSTIC, \ 594 "Print additional statistics per compilation") \ 595 \ 596 product(bool, PrintAdapterHandlers, false, DIAGNOSTIC, \ 597 "Print code generated for i2c/c2i adapters") \ 598 \ 599 product(bool, VerifyAdapterCalls, trueInDebug, DIAGNOSTIC, \ 600 "Verify that i2c/c2i adapters are called properly") \ 601 \ 602 develop(bool, VerifyAdapterSharing, false, \ 603 "Verify that the code for shared adapters is the equivalent") \ 604 \ 605 product(bool, PrintAssembly, false, DIAGNOSTIC, \ 606 "Print assembly code (using external disassembler.so)") \ 607 \ 608 product(ccstr, PrintAssemblyOptions, nullptr, DIAGNOSTIC, \ 609 "Print options string passed to disassembler.so") \ 610 \ 611 notproduct(bool, PrintNMethodStatistics, false, \ 612 "Print a summary statistic for the generated nmethods") \ 613 \ 614 product(bool, PrintNMethods, false, DIAGNOSTIC, \ 615 "Print assembly code for nmethods when generated") \ 616 \ 617 product(bool, PrintNativeNMethods, false, DIAGNOSTIC, \ 618 "Print assembly code for native nmethods when generated") \ 619 \ 620 develop(bool, PrintDebugInfo, false, \ 621 "Print debug information for all nmethods when generated") \ 622 \ 623 develop(bool, PrintRelocations, false, \ 624 "Print relocation information for all nmethods when generated") \ 625 \ 626 develop(bool, PrintDependencies, false, \ 627 "Print dependency information for all nmethods when generated") \ 628 \ 629 develop(bool, PrintExceptionHandlers, false, \ 630 "Print exception handler tables for all nmethods when generated") \ 631 \ 632 develop(bool, StressCompiledExceptionHandlers, false, \ 633 "Exercise compiled exception handlers") \ 634 \ 635 develop(bool, InterceptOSException, false, \ 636 "Start debugger when an implicit OS (e.g. null pointer) " \ 637 "exception happens") \ 638 \ 639 product(bool, PrintCodeCache, false, \ 640 "Print the code cache memory usage when exiting") \ 641 \ 642 develop(bool, PrintCodeCache2, false, \ 643 "Print detailed usage information on the code cache when exiting")\ 644 \ 645 product(bool, PrintCodeCacheOnCompilation, false, \ 646 "Print the code cache memory usage each time a method is " \ 647 "compiled") \ 648 \ 649 product(bool, PrintCodeHeapAnalytics, false, DIAGNOSTIC, \ 650 "Print code heap usage statistics on exit and on full condition") \ 651 \ 652 product(bool, PrintStubCode, false, DIAGNOSTIC, \ 653 "Print generated stub code") \ 654 \ 655 product(bool, StackTraceInThrowable, true, \ 656 "Collect backtrace in throwable when exception happens") \ 657 \ 658 product(bool, OmitStackTraceInFastThrow, true, \ 659 "Omit backtraces for some 'hot' exceptions in optimized code") \ 660 \ 661 product(bool, ShowCodeDetailsInExceptionMessages, true, MANAGEABLE, \ 662 "Show exception messages from RuntimeExceptions that contain " \ 663 "snippets of the failing code. Disable this to improve privacy.") \ 664 \ 665 product(bool, PrintWarnings, true, \ 666 "Print JVM warnings to output stream") \ 667 \ 668 product(bool, RegisterFinalizersAtInit, true, \ 669 "Register finalizable objects at end of Object.<init> or " \ 670 "after allocation") \ 671 \ 672 develop(bool, RegisterReferences, true, \ 673 "Tell whether the VM should register soft/weak/final/phantom " \ 674 "references") \ 675 \ 676 develop(bool, PrintCodeCacheExtension, false, \ 677 "Print extension of code cache") \ 678 \ 679 develop(bool, UsePrivilegedStack, true, \ 680 "Enable the security JVM functions") \ 681 \ 682 product(bool, ClassUnloading, true, \ 683 "Do unloading of classes") \ 684 \ 685 product(bool, ClassUnloadingWithConcurrentMark, true, \ 686 "Do unloading of classes with a concurrent marking cycle") \ 687 \ 688 notproduct(bool, PrintSystemDictionaryAtExit, false, \ 689 "Print the system dictionary at exit") \ 690 \ 691 notproduct(bool, PrintClassLoaderDataGraphAtExit, false, \ 692 "Print the class loader data graph at exit") \ 693 \ 694 product(bool, AllowParallelDefineClass, false, \ 695 "Allow parallel defineClass requests for class loaders " \ 696 "registering as parallel capable") \ 697 \ 698 product_pd(bool, DontYieldALot, \ 699 "Throw away obvious excess yield calls") \ 700 \ 701 product(bool, DisablePrimordialThreadGuardPages, false, EXPERIMENTAL, \ 702 "Disable the use of stack guard pages if the JVM is loaded " \ 703 "on the primordial process thread") \ 704 \ 705 product(bool, DoJVMTIVirtualThreadTransitions, true, EXPERIMENTAL, \ 706 "Do JVMTI virtual thread mount/unmount transitions " \ 707 "(disabling this flag implies no JVMTI events are posted)") \ 708 \ 709 /* notice: the max range value here is max_jint, not max_intx */ \ 710 /* because of overflow issue */ \ 711 product(intx, AsyncDeflationInterval, 250, DIAGNOSTIC, \ 712 "Async deflate idle monitors every so many milliseconds when " \ 713 "MonitorUsedDeflationThreshold is exceeded (0 is off).") \ 714 range(0, max_jint) \ 715 \ 716 /* notice: the max range value here is max_jint, not max_intx */ \ 717 /* because of overflow issue */ \ 718 product(intx, GuaranteedAsyncDeflationInterval, 60000, DIAGNOSTIC, \ 719 "Async deflate idle monitors every so many milliseconds even " \ 720 "when MonitorUsedDeflationThreshold is NOT exceeded (0 is off).") \ 721 range(0, max_jint) \ 722 \ 723 product(size_t, AvgMonitorsPerThreadEstimate, 1024, DIAGNOSTIC, \ 724 "Used to estimate a variable ceiling based on number of threads " \ 725 "for use with MonitorUsedDeflationThreshold (0 is off).") \ 726 range(0, max_uintx) \ 727 \ 728 /* notice: the max range value here is max_jint, not max_intx */ \ 729 /* because of overflow issue */ \ 730 product(intx, MonitorDeflationMax, 1000000, DIAGNOSTIC, \ 731 "The maximum number of monitors to deflate, unlink and delete " \ 732 "at one time (minimum is 1024).") \ 733 range(1024, max_jint) \ 734 \ 735 product(intx, MonitorUsedDeflationThreshold, 90, DIAGNOSTIC, \ 736 "Percentage of used monitors before triggering deflation (0 is " \ 737 "off). The check is performed on GuaranteedSafepointInterval, " \ 738 "AsyncDeflationInterval or GuaranteedAsyncDeflationInterval, " \ 739 "whichever is lower.") \ 740 range(0, 100) \ 741 \ 742 product(uintx, NoAsyncDeflationProgressMax, 3, DIAGNOSTIC, \ 743 "Max number of no progress async deflation attempts to tolerate " \ 744 "before adjusting the in_use_list_ceiling up (0 is off).") \ 745 range(0, max_uintx) \ 746 \ 747 product(intx, hashCode, 5, EXPERIMENTAL, \ 748 "(Unstable) select hashCode generation algorithm") \ 749 \ 750 product(bool, ReduceSignalUsage, false, \ 751 "Reduce the use of OS signals in Java and/or the VM") \ 752 \ 753 develop(bool, LoadLineNumberTables, true, \ 754 "Tell whether the class file parser loads line number tables") \ 755 \ 756 develop(bool, LoadLocalVariableTables, true, \ 757 "Tell whether the class file parser loads local variable tables") \ 758 \ 759 develop(bool, LoadLocalVariableTypeTables, true, \ 760 "Tell whether the class file parser loads local variable type" \ 761 "tables") \ 762 \ 763 product(bool, AllowUserSignalHandlers, false, \ 764 "Application will install primary signal handlers for the JVM " \ 765 "(Unix only)") \ 766 \ 767 product(bool, UseSignalChaining, true, \ 768 "Use signal-chaining to invoke signal handlers installed " \ 769 "by the application (Unix only)") \ 770 \ 771 product(bool, RestoreMXCSROnJNICalls, false, \ 772 "Restore MXCSR when returning from JNI calls") \ 773 \ 774 product(bool, CheckJNICalls, false, \ 775 "Verify all arguments to JNI calls") \ 776 \ 777 product(bool, UseFastJNIAccessors, true, \ 778 "Use optimized versions of Get<Primitive>Field") \ 779 \ 780 product(intx, MaxJNILocalCapacity, 65536, \ 781 "Maximum allowable local JNI handle capacity to " \ 782 "EnsureLocalCapacity() and PushLocalFrame(), " \ 783 "where <= 0 is unlimited, default: 65536") \ 784 range(min_intx, max_intx) \ 785 \ 786 product(bool, EagerXrunInit, false, \ 787 "Eagerly initialize -Xrun libraries; allows startup profiling, " \ 788 "but not all -Xrun libraries may support the state of the VM " \ 789 "at this time") \ 790 \ 791 product(bool, PreserveAllAnnotations, false, \ 792 "Preserve RuntimeInvisibleAnnotations as well " \ 793 "as RuntimeVisibleAnnotations") \ 794 \ 795 develop(uintx, PreallocatedOutOfMemoryErrorCount, 4, \ 796 "Number of OutOfMemoryErrors preallocated with backtrace") \ 797 \ 798 product(bool, UseXMMForArrayCopy, false, \ 799 "Use SSE2 MOVQ instruction for Arraycopy") \ 800 \ 801 notproduct(bool, PrintFieldLayout, false, \ 802 "Print field layout for each class") \ 803 \ 804 /* Need to limit the extent of the padding to reasonable size. */\ 805 /* 8K is well beyond the reasonable HW cache line size, even with */\ 806 /* aggressive prefetching, while still leaving the room for segregating */\ 807 /* among the distinct pages. */\ 808 product(intx, ContendedPaddingWidth, 128, \ 809 "How many bytes to pad the fields/classes marked @Contended with")\ 810 range(0, 8192) \ 811 constraint(ContendedPaddingWidthConstraintFunc,AfterErgo) \ 812 \ 813 product(bool, EnableContended, true, \ 814 "Enable @Contended annotation support") \ 815 \ 816 product(bool, RestrictContended, true, \ 817 "Restrict @Contended to trusted classes") \ 818 \ 819 product(int, DiagnoseSyncOnValueBasedClasses, 0, DIAGNOSTIC, \ 820 "Detect and take action upon identifying synchronization on " \ 821 "value based classes. Modes: " \ 822 "0: off; " \ 823 "1: exit with fatal error; " \ 824 "2: log message to stdout. Output file can be specified with " \ 825 " -Xlog:valuebasedclasses. If JFR is running it will " \ 826 " also generate JFR events.") \ 827 range(0, 2) \ 828 \ 829 product(bool, ExitOnOutOfMemoryError, false, \ 830 "JVM exits on the first occurrence of an out-of-memory error " \ 831 "thrown from JVM") \ 832 \ 833 product(bool, CrashOnOutOfMemoryError, false, \ 834 "JVM aborts, producing an error log and core/mini dump, on the " \ 835 "first occurrence of an out-of-memory error thrown from JVM") \ 836 \ 837 /* tracing */ \ 838 \ 839 develop(bool, StressRewriter, false, \ 840 "Stress linktime bytecode rewriting") \ 841 \ 842 product(ccstr, TraceJVMTI, nullptr, \ 843 "Trace flags for JVMTI functions and events") \ 844 \ 845 product(bool, StressLdcRewrite, false, DIAGNOSTIC, \ 846 "Force ldc -> ldc_w rewrite during RedefineClasses. " \ 847 "This option can change an EMCP method into an obsolete method " \ 848 "and can affect tests that expect specific methods to be EMCP. " \ 849 "This option should be used with caution.") \ 850 \ 851 product(bool, AllowRedefinitionToAddDeleteMethods, false, \ 852 "(Deprecated) Allow redefinition to add and delete private " \ 853 "static or final methods for compatibility with old releases") \ 854 \ 855 develop(bool, TraceBytecodes, false, \ 856 "Trace bytecode execution") \ 857 \ 858 develop(bool, TraceICs, false, \ 859 "Trace inline cache changes") \ 860 \ 861 notproduct(bool, TraceInvocationCounterOverflow, false, \ 862 "Trace method invocation counter overflow") \ 863 \ 864 develop(bool, TraceInlineCacheClearing, false, \ 865 "Trace clearing of inline caches in nmethods") \ 866 \ 867 develop(bool, VerifyDependencies, trueInDebug, \ 868 "Exercise and verify the compilation dependency mechanism") \ 869 \ 870 develop(bool, TraceNewOopMapGeneration, false, \ 871 "Trace OopMapGeneration") \ 872 \ 873 develop(bool, TraceNewOopMapGenerationDetailed, false, \ 874 "Trace OopMapGeneration: print detailed cell states") \ 875 \ 876 develop(bool, TimeOopMap, false, \ 877 "Time calls to GenerateOopMap::compute_map() in sum") \ 878 \ 879 develop(bool, TimeOopMap2, false, \ 880 "Time calls to GenerateOopMap::compute_map() individually") \ 881 \ 882 develop(bool, TraceOopMapRewrites, false, \ 883 "Trace rewriting of methods during oop map generation") \ 884 \ 885 develop(bool, TraceICBuffer, false, \ 886 "Trace usage of IC buffer") \ 887 \ 888 develop(bool, TraceCompiledIC, false, \ 889 "Trace changes of compiled IC") \ 890 \ 891 develop(bool, FLSVerifyDictionary, false, \ 892 "Do lots of (expensive) FLS dictionary verification") \ 893 \ 894 product(uintx, ProcessDistributionStride, 4, \ 895 "Stride through processors when distributing processes") \ 896 range(0, max_juint) \ 897 \ 898 develop(bool, TraceFinalizerRegistration, false, \ 899 "Trace registration of final references") \ 900 \ 901 product(bool, IgnoreEmptyClassPaths, false, \ 902 "Ignore empty path elements in -classpath") \ 903 \ 904 product(bool, PrintHeapAtSIGBREAK, true, \ 905 "Print heap layout in response to SIGBREAK") \ 906 \ 907 product(bool, PrintClassHistogram, false, MANAGEABLE, \ 908 "Print a histogram of class instances") \ 909 \ 910 product(double, ObjectCountCutOffPercent, 0.5, EXPERIMENTAL, \ 911 "The percentage of the used heap that the instances of a class " \ 912 "must occupy for the class to generate a trace event") \ 913 range(0.0, 100.0) \ 914 \ 915 /* JVMTI heap profiling */ \ 916 \ 917 product(bool, VerifyBeforeIteration, false, DIAGNOSTIC, \ 918 "Verify memory system before JVMTI iteration") \ 919 \ 920 /* compiler */ \ 921 \ 922 /* notice: the max range value here is max_jint, not max_intx */ \ 923 /* because of overflow issue */ \ 924 product(intx, CICompilerCount, CI_COMPILER_COUNT, \ 925 "Number of compiler threads to run") \ 926 range(0, max_jint) \ 927 constraint(CICompilerCountConstraintFunc, AfterErgo) \ 928 \ 929 product(bool, UseDynamicNumberOfCompilerThreads, true, \ 930 "Dynamically choose the number of parallel compiler threads") \ 931 \ 932 product(bool, ReduceNumberOfCompilerThreads, true, DIAGNOSTIC, \ 933 "Reduce the number of parallel compiler threads when they " \ 934 "are not used") \ 935 \ 936 product(bool, TraceCompilerThreads, false, DIAGNOSTIC, \ 937 "Trace creation and removal of compiler threads") \ 938 \ 939 develop(bool, InjectCompilerCreationFailure, false, \ 940 "Inject thread creation failures for " \ 941 "UseDynamicNumberOfCompilerThreads") \ 942 \ 943 develop(bool, GenerateSynchronizationCode, true, \ 944 "generate locking/unlocking code for synchronized methods and " \ 945 "monitors") \ 946 \ 947 product_pd(bool, ImplicitNullChecks, DIAGNOSTIC, \ 948 "Generate code for implicit null checks") \ 949 \ 950 product_pd(bool, TrapBasedNullChecks, \ 951 "Generate code for null checks that uses a cmp and trap " \ 952 "instruction raising SIGTRAP. This is only used if an access to" \ 953 "null (+offset) will not raise a SIGSEGV, i.e.," \ 954 "ImplicitNullChecks don't work (PPC64).") \ 955 \ 956 product(bool, EnableThreadSMRStatistics, trueInDebug, DIAGNOSTIC, \ 957 "Enable Thread SMR Statistics") \ 958 \ 959 product(bool, UseNotificationThread, true, \ 960 "Use Notification Thread") \ 961 \ 962 product(bool, Inline, true, \ 963 "Enable inlining") \ 964 \ 965 product(bool, ClipInlining, true, \ 966 "Clip inlining if aggregate method exceeds DesiredMethodLimit") \ 967 \ 968 develop(bool, UseCHA, true, \ 969 "Enable CHA") \ 970 \ 971 product(bool, UseVtableBasedCHA, true, DIAGNOSTIC, \ 972 "Use vtable information during CHA") \ 973 \ 974 product(bool, UseTypeProfile, true, \ 975 "Check interpreter profile for historically monomorphic calls") \ 976 \ 977 product(bool, PrintInlining, false, DIAGNOSTIC, \ 978 "Print inlining optimizations") \ 979 \ 980 product(bool, UsePopCountInstruction, false, \ 981 "Use population count instruction") \ 982 \ 983 develop(bool, TraceMethodReplacement, false, \ 984 "Print when methods are replaced do to recompilation") \ 985 \ 986 product(bool, PrintMethodFlushingStatistics, false, DIAGNOSTIC, \ 987 "print statistics about method flushing") \ 988 \ 989 product(intx, MinPassesBeforeFlush, 10, DIAGNOSTIC, \ 990 "Minimum number of sweeper passes before an nmethod " \ 991 "can be flushed") \ 992 range(0, max_intx) \ 993 \ 994 develop(bool, StressCodeBuffers, false, \ 995 "Exercise code buffer expansion and other rare state changes") \ 996 \ 997 product(bool, DebugNonSafepoints, trueInDebug, DIAGNOSTIC, \ 998 "Generate extra debugging information for non-safepoints in " \ 999 "nmethods") \ 1000 \ 1001 product(bool, PrintVMOptions, false, \ 1002 "Print flags that appeared on the command line") \ 1003 \ 1004 product(bool, IgnoreUnrecognizedVMOptions, false, \ 1005 "Ignore unrecognized VM options") \ 1006 \ 1007 product(bool, PrintCommandLineFlags, false, \ 1008 "Print flags specified on command line or set by ergonomics") \ 1009 \ 1010 product(bool, PrintFlagsInitial, false, \ 1011 "Print all VM flags before argument processing and exit VM") \ 1012 \ 1013 product(bool, PrintFlagsFinal, false, \ 1014 "Print all VM flags after argument and ergonomic processing") \ 1015 \ 1016 notproduct(bool, PrintFlagsWithComments, false, \ 1017 "Print all VM flags with default values and descriptions and " \ 1018 "exit") \ 1019 \ 1020 product(bool, PrintFlagsRanges, false, \ 1021 "Print VM flags and their ranges") \ 1022 \ 1023 product(bool, SerializeVMOutput, true, DIAGNOSTIC, \ 1024 "Use a mutex to serialize output to tty and LogFile") \ 1025 \ 1026 product(bool, DisplayVMOutput, true, DIAGNOSTIC, \ 1027 "Display all VM output on the tty, independently of LogVMOutput") \ 1028 \ 1029 product(bool, LogVMOutput, false, DIAGNOSTIC, \ 1030 "Save VM output to LogFile") \ 1031 \ 1032 product(ccstr, LogFile, nullptr, DIAGNOSTIC, \ 1033 "If LogVMOutput or LogCompilation is on, save VM output to " \ 1034 "this file [default: ./hotspot_pid%p.log] (%p replaced with pid)")\ 1035 \ 1036 product(ccstr, ErrorFile, nullptr, \ 1037 "If an error occurs, save the error data to this file " \ 1038 "[default: ./hs_err_pid%p.log] (%p replaced with pid)") \ 1039 \ 1040 product(bool, ExtensiveErrorReports, \ 1041 PRODUCT_ONLY(false) NOT_PRODUCT(true), \ 1042 "Error reports are more extensive.") \ 1043 \ 1044 product(bool, DisplayVMOutputToStderr, false, \ 1045 "If DisplayVMOutput is true, display all VM output to stderr") \ 1046 \ 1047 product(bool, DisplayVMOutputToStdout, false, \ 1048 "If DisplayVMOutput is true, display all VM output to stdout") \ 1049 \ 1050 product(bool, ErrorFileToStderr, false, \ 1051 "If true, error data is printed to stderr instead of a file") \ 1052 \ 1053 product(bool, ErrorFileToStdout, false, \ 1054 "If true, error data is printed to stdout instead of a file") \ 1055 \ 1056 develop(bool, VerifyHeavyMonitors, false, \ 1057 "Checks that no stack locking happens when using " \ 1058 "-XX:LockingMode=0 (LM_MONITOR)") \ 1059 \ 1060 product(bool, PrintStringTableStatistics, false, \ 1061 "print statistics about the StringTable and SymbolTable") \ 1062 \ 1063 product(bool, VerifyStringTableAtExit, false, DIAGNOSTIC, \ 1064 "verify StringTable contents at exit") \ 1065 \ 1066 notproduct(bool, PrintSymbolTableSizeHistogram, false, \ 1067 "print histogram of the symbol table") \ 1068 \ 1069 product(ccstr, AbortVMOnException, nullptr, DIAGNOSTIC, \ 1070 "Call fatal if this exception is thrown. Example: " \ 1071 "java -XX:AbortVMOnException=java.lang.NullPointerException Foo") \ 1072 \ 1073 product(ccstr, AbortVMOnExceptionMessage, nullptr, DIAGNOSTIC, \ 1074 "Call fatal if the exception pointed by AbortVMOnException " \ 1075 "has this message") \ 1076 \ 1077 develop(bool, DebugVtables, false, \ 1078 "add debugging code to vtable dispatch") \ 1079 \ 1080 product(bool, RangeCheckElimination, true, \ 1081 "Eliminate range checks") \ 1082 \ 1083 develop_pd(bool, UncommonNullCast, \ 1084 "track occurrences of null in casts; adjust compiler tactics") \ 1085 \ 1086 develop(bool, TypeProfileCasts, true, \ 1087 "treat casts like calls for purposes of type profiling") \ 1088 \ 1089 develop(bool, TraceLivenessGen, false, \ 1090 "Trace the generation of liveness analysis information") \ 1091 \ 1092 notproduct(bool, TraceLivenessQuery, false, \ 1093 "Trace queries of liveness analysis information") \ 1094 \ 1095 notproduct(bool, CollectIndexSetStatistics, false, \ 1096 "Collect information about IndexSets") \ 1097 \ 1098 develop(intx, FastAllocateSizeLimit, 128*K, \ 1099 /* Note: This value is zero mod 1<<13 for a cheap sparc set. */ \ 1100 "Inline allocations larger than this in doublewords must go slow")\ 1101 \ 1102 product_pd(bool, CompactStrings, \ 1103 "Enable Strings to use single byte chars in backing store") \ 1104 \ 1105 product_pd(uint, TypeProfileLevel, \ 1106 "=XYZ, with Z: Type profiling of arguments at call; " \ 1107 "Y: Type profiling of return value at call; " \ 1108 "X: Type profiling of parameters to methods; " \ 1109 "X, Y and Z in 0=off ; 1=jsr292 only; 2=all methods") \ 1110 constraint(TypeProfileLevelConstraintFunc, AfterErgo) \ 1111 \ 1112 product(intx, TypeProfileArgsLimit, 2, \ 1113 "max number of call arguments to consider for type profiling") \ 1114 range(0, 16) \ 1115 \ 1116 product(intx, TypeProfileParmsLimit, 2, \ 1117 "max number of incoming parameters to consider for type profiling"\ 1118 ", -1 for all") \ 1119 range(-1, 64) \ 1120 \ 1121 /* statistics */ \ 1122 develop(bool, CountCompiledCalls, false, \ 1123 "Count method invocations") \ 1124 \ 1125 notproduct(bool, ICMissHistogram, false, \ 1126 "Produce histogram of IC misses") \ 1127 \ 1128 /* interpreter */ \ 1129 product_pd(bool, RewriteBytecodes, \ 1130 "Allow rewriting of bytecodes (bytecodes are not immutable)") \ 1131 \ 1132 product_pd(bool, RewriteFrequentPairs, \ 1133 "Rewrite frequently used bytecode pairs into a single bytecode") \ 1134 \ 1135 product(bool, PrintInterpreter, false, DIAGNOSTIC, \ 1136 "Print the generated interpreter code") \ 1137 \ 1138 product(bool, UseInterpreter, true, \ 1139 "Use interpreter for non-compiled methods") \ 1140 \ 1141 develop(bool, UseFastSignatureHandlers, true, \ 1142 "Use fast signature handlers for native calls") \ 1143 \ 1144 product(bool, UseLoopCounter, true, \ 1145 "Increment invocation counter on backward branch") \ 1146 \ 1147 product_pd(bool, UseOnStackReplacement, \ 1148 "Use on stack replacement, calls runtime if invoc. counter " \ 1149 "overflows in loop") \ 1150 \ 1151 notproduct(bool, TraceOnStackReplacement, false, \ 1152 "Trace on stack replacement") \ 1153 \ 1154 product_pd(bool, PreferInterpreterNativeStubs, \ 1155 "Use always interpreter stubs for native methods invoked via " \ 1156 "interpreter") \ 1157 \ 1158 develop(bool, CountBytecodes, false, \ 1159 "Count number of bytecodes executed") \ 1160 \ 1161 develop(bool, PrintBytecodeHistogram, false, \ 1162 "Print histogram of the executed bytecodes") \ 1163 \ 1164 develop(bool, PrintBytecodePairHistogram, false, \ 1165 "Print histogram of the executed bytecode pairs") \ 1166 \ 1167 product(bool, PrintSignatureHandlers, false, DIAGNOSTIC, \ 1168 "Print code generated for native method signature handlers") \ 1169 \ 1170 develop(bool, VerifyOops, false, \ 1171 "Do plausibility checks for oops") \ 1172 \ 1173 develop(bool, CheckUnhandledOops, false, \ 1174 "Check for unhandled oops in VM code") \ 1175 \ 1176 develop(bool, VerifyJNIFields, trueInDebug, \ 1177 "Verify jfieldIDs for instance fields") \ 1178 \ 1179 develop(bool, VerifyFPU, false, \ 1180 "Verify FPU state (check for NaN's, etc.)") \ 1181 \ 1182 develop(bool, VerifyActivationFrameSize, false, \ 1183 "Verify that activation frame didn't become smaller than its " \ 1184 "minimal size") \ 1185 \ 1186 develop(bool, TraceFrequencyInlining, false, \ 1187 "Trace frequency based inlining") \ 1188 \ 1189 develop_pd(bool, InlineIntrinsics, \ 1190 "Use intrinsics in Interpreter that can be statically resolved") \ 1191 \ 1192 product_pd(bool, ProfileInterpreter, \ 1193 "Profile at the bytecode level during interpretation") \ 1194 \ 1195 develop_pd(bool, ProfileTraps, \ 1196 "Profile deoptimization traps at the bytecode level") \ 1197 \ 1198 product(intx, ProfileMaturityPercentage, 20, \ 1199 "number of method invocations/branches (expressed as % of " \ 1200 "CompileThreshold) before using the method's profile") \ 1201 range(0, 100) \ 1202 \ 1203 product(bool, PrintMethodData, false, DIAGNOSTIC, \ 1204 "Print the results of +ProfileInterpreter at end of run") \ 1205 \ 1206 develop(bool, VerifyDataPointer, trueInDebug, \ 1207 "Verify the method data pointer during interpreter profiling") \ 1208 \ 1209 notproduct(bool, CrashGCForDumpingJavaThread, false, \ 1210 "Manually make GC thread crash then dump java stack trace; " \ 1211 "Test only") \ 1212 \ 1213 /* compilation */ \ 1214 product(bool, UseCompiler, true, \ 1215 "Use Just-In-Time compilation") \ 1216 \ 1217 product(bool, UseCounterDecay, true, \ 1218 "Adjust recompilation counters") \ 1219 \ 1220 develop(intx, CounterHalfLifeTime, 30, \ 1221 "Half-life time of invocation counters (in seconds)") \ 1222 \ 1223 develop(intx, CounterDecayMinIntervalLength, 500, \ 1224 "The minimum interval (in milliseconds) between invocation of " \ 1225 "CounterDecay") \ 1226 \ 1227 product(bool, AlwaysCompileLoopMethods, false, \ 1228 "When using recompilation, never interpret methods " \ 1229 "containing loops") \ 1230 \ 1231 product(intx, AllocatePrefetchStyle, 1, \ 1232 "0 = no prefetch, " \ 1233 "1 = generate prefetch instructions for each allocation, " \ 1234 "2 = use TLAB watermark to gate allocation prefetch, " \ 1235 "3 = generate one prefetch instruction per cache line") \ 1236 range(0, 3) \ 1237 \ 1238 product(intx, AllocatePrefetchDistance, -1, \ 1239 "Distance to prefetch ahead of allocation pointer. " \ 1240 "-1: use system-specific value (automatically determined") \ 1241 constraint(AllocatePrefetchDistanceConstraintFunc,AfterMemoryInit)\ 1242 \ 1243 product(intx, AllocatePrefetchLines, 3, \ 1244 "Number of lines to prefetch ahead of array allocation pointer") \ 1245 range(1, 64) \ 1246 \ 1247 product(intx, AllocateInstancePrefetchLines, 1, \ 1248 "Number of lines to prefetch ahead of instance allocation " \ 1249 "pointer") \ 1250 range(1, 64) \ 1251 \ 1252 product(intx, AllocatePrefetchStepSize, 16, \ 1253 "Step size in bytes of sequential prefetch instructions") \ 1254 range(1, 512) \ 1255 constraint(AllocatePrefetchStepSizeConstraintFunc,AfterMemoryInit)\ 1256 \ 1257 product(intx, AllocatePrefetchInstr, 0, \ 1258 "Select instruction to prefetch ahead of allocation pointer") \ 1259 constraint(AllocatePrefetchInstrConstraintFunc, AfterMemoryInit) \ 1260 \ 1261 /* deoptimization */ \ 1262 product(bool, TraceDeoptimization, false, DIAGNOSTIC, \ 1263 "Trace deoptimization") \ 1264 \ 1265 develop(bool, PrintDeoptimizationDetails, false, \ 1266 "Print more information about deoptimization") \ 1267 \ 1268 develop(bool, DebugDeoptimization, false, \ 1269 "Tracing various information while debugging deoptimization") \ 1270 \ 1271 product(double, SelfDestructTimer, 0.0, \ 1272 "Will cause VM to terminate after a given time " \ 1273 "(in fractional minutes) " \ 1274 "(0.0 means off)") \ 1275 range(0.0, (double)max_intx) \ 1276 \ 1277 product(intx, MaxJavaStackTraceDepth, 1024, \ 1278 "The maximum number of lines in the stack trace for Java " \ 1279 "exceptions (0 means all)") \ 1280 range(0, max_jint/2) \ 1281 \ 1282 /* notice: the max range value here is max_jint, not max_intx */ \ 1283 /* because of overflow issue */ \ 1284 product(intx, GuaranteedSafepointInterval, 1000, DIAGNOSTIC, \ 1285 "Guarantee a safepoint (at least) every so many milliseconds " \ 1286 "(0 means none)") \ 1287 range(0, max_jint) \ 1288 \ 1289 product(intx, SafepointTimeoutDelay, 10000, \ 1290 "Delay in milliseconds for option SafepointTimeout") \ 1291 range(0, max_intx LP64_ONLY(/MICROUNITS)) \ 1292 \ 1293 product(bool, UseSystemMemoryBarrier, false, \ 1294 "Try to enable system memory barrier if supported by OS") \ 1295 \ 1296 product(intx, NmethodSweepActivity, 4, \ 1297 "Removes cold nmethods from code cache if > 0. Higher values " \ 1298 "result in more aggressive sweeping") \ 1299 range(0, 2000) \ 1300 \ 1301 develop(intx, MallocCatchPtr, -1, \ 1302 "Hit breakpoint when mallocing/freeing this pointer") \ 1303 \ 1304 develop(intx, StackPrintLimit, 100, \ 1305 "number of stack frames to print in VM-level stack dump") \ 1306 \ 1307 product(int, ErrorLogPrintCodeLimit, 3, DIAGNOSTIC, \ 1308 "max number of compiled code units to print in error log") \ 1309 range(0, VMError::max_error_log_print_code) \ 1310 \ 1311 notproduct(intx, MaxElementPrintSize, 256, \ 1312 "maximum number of elements to print") \ 1313 \ 1314 notproduct(intx, MaxSubklassPrintSize, 4, \ 1315 "maximum number of subklasses to print when printing klass") \ 1316 \ 1317 develop(intx, MaxForceInlineLevel, 100, \ 1318 "maximum number of nested calls that are forced for inlining " \ 1319 "(using CompileCommand or marked w/ @ForceInline)") \ 1320 range(0, max_jint) \ 1321 \ 1322 develop(intx, MethodHistogramCutoff, 100, \ 1323 "The cutoff value for method invocation histogram (+CountCalls)") \ 1324 \ 1325 develop(intx, DontYieldALotInterval, 10, \ 1326 "Interval between which yields will be dropped (milliseconds)") \ 1327 \ 1328 notproduct(intx, DeoptimizeALotInterval, 5, \ 1329 "Number of exits until DeoptimizeALot kicks in") \ 1330 \ 1331 notproduct(intx, ZombieALotInterval, 5, \ 1332 "Number of exits until ZombieALot kicks in") \ 1333 \ 1334 product(ccstr, MallocLimit, nullptr, DIAGNOSTIC, \ 1335 "Limit malloc allocation size from VM. Reaching a limit will " \ 1336 "trigger an action (see flag). This feature requires " \ 1337 "NativeMemoryTracking=summary or NativeMemoryTracking=detail." \ 1338 "Usage:" \ 1339 "\"-XX:MallocLimit=<size>[:<flag>]\" sets a total limit." \ 1340 "\"-XX:MallocLimit=<category>:<size>[:<flag>][,<category>:<size>[:<flag>] ...]\"" \ 1341 "sets one or more category-specific limits." \ 1342 "<flag> defines the action upon reaching the limit:" \ 1343 "\"fatal\": end VM with a fatal error at the allocation site" \ 1344 "\"oom\" : will mimic a native OOM" \ 1345 "If <flag> is omitted, \"fatal\" is the default." \ 1346 "Examples:\n" \ 1347 "-XX:MallocLimit=2g" \ 1348 "-XX:MallocLimit=2g:oom" \ 1349 "-XX:MallocLimit=compiler:200m:oom,code:100m") \ 1350 \ 1351 product(intx, TypeProfileWidth, 2, \ 1352 "Number of receiver types to record in call/cast profile") \ 1353 range(0, 8) \ 1354 \ 1355 develop(intx, BciProfileWidth, 2, \ 1356 "Number of return bci's to record in ret profile") \ 1357 \ 1358 product(intx, PerMethodRecompilationCutoff, 400, \ 1359 "After recompiling N times, stay in the interpreter (-1=>'Inf')") \ 1360 range(-1, max_intx) \ 1361 \ 1362 product(intx, PerBytecodeRecompilationCutoff, 200, \ 1363 "Per-BCI limit on repeated recompilation (-1=>'Inf')") \ 1364 range(-1, max_intx) \ 1365 \ 1366 product(intx, PerMethodTrapLimit, 100, \ 1367 "Limit on traps (of one kind) in a method (includes inlines)") \ 1368 range(0, max_jint) \ 1369 \ 1370 product(intx, PerMethodSpecTrapLimit, 5000, EXPERIMENTAL, \ 1371 "Limit on speculative traps (of one kind) in a method " \ 1372 "(includes inlines)") \ 1373 range(0, max_jint) \ 1374 \ 1375 product(intx, PerBytecodeTrapLimit, 4, \ 1376 "Limit on traps (of one kind) at a particular BCI") \ 1377 range(0, max_jint) \ 1378 \ 1379 product(intx, SpecTrapLimitExtraEntries, 3, EXPERIMENTAL, \ 1380 "Extra method data trap entries for speculation") \ 1381 \ 1382 product(double, InlineFrequencyRatio, 0.25, DIAGNOSTIC, \ 1383 "Ratio of call site execution to caller method invocation") \ 1384 \ 1385 product(double, MinInlineFrequencyRatio, 0.0085, DIAGNOSTIC, \ 1386 "Minimum ratio of call site execution to caller method" \ 1387 "invocation to be considered for inlining") \ 1388 \ 1389 develop(intx, InlineThrowCount, 50, \ 1390 "Force inlining of interpreted methods that throw this often") \ 1391 range(0, max_jint) \ 1392 \ 1393 develop(intx, InlineThrowMaxSize, 200, \ 1394 "Force inlining of throwing methods smaller than this") \ 1395 range(0, max_jint) \ 1396 \ 1397 product(size_t, MetaspaceSize, NOT_LP64(16 * M) LP64_ONLY(21 * M), \ 1398 "Initial threshold (in bytes) at which a garbage collection " \ 1399 "is done to reduce Metaspace usage") \ 1400 constraint(MetaspaceSizeConstraintFunc,AfterErgo) \ 1401 \ 1402 product(size_t, MaxMetaspaceSize, max_uintx, \ 1403 "Maximum size of Metaspaces (in bytes)") \ 1404 constraint(MaxMetaspaceSizeConstraintFunc,AfterErgo) \ 1405 \ 1406 product(size_t, CompressedClassSpaceSize, 1*G, \ 1407 "Maximum size of class area in Metaspace when compressed " \ 1408 "class pointers are used") \ 1409 range(1*M, 3*G) \ 1410 \ 1411 develop(size_t, CompressedClassSpaceBaseAddress, 0, \ 1412 "Force the class space to be allocated at this address or " \ 1413 "fails VM initialization (requires -Xshare=off.") \ 1414 \ 1415 product(bool, PrintMetaspaceStatisticsAtExit, false, DIAGNOSTIC, \ 1416 "Print metaspace statistics upon VM exit.") \ 1417 \ 1418 develop(bool, MetaspaceGuardAllocations, false, \ 1419 "Metapace allocations are guarded.") \ 1420 \ 1421 product(uintx, MinHeapFreeRatio, 40, MANAGEABLE, \ 1422 "The minimum percentage of heap free after GC to avoid expansion."\ 1423 " For most GCs this applies to the old generation. In G1 and" \ 1424 " ParallelGC it applies to the whole heap.") \ 1425 range(0, 100) \ 1426 constraint(MinHeapFreeRatioConstraintFunc,AfterErgo) \ 1427 \ 1428 product(uintx, MaxHeapFreeRatio, 70, MANAGEABLE, \ 1429 "The maximum percentage of heap free after GC to avoid shrinking."\ 1430 " For most GCs this applies to the old generation. In G1 and" \ 1431 " ParallelGC it applies to the whole heap.") \ 1432 range(0, 100) \ 1433 constraint(MaxHeapFreeRatioConstraintFunc,AfterErgo) \ 1434 \ 1435 product(bool, ShrinkHeapInSteps, true, \ 1436 "When disabled, informs the GC to shrink the java heap directly" \ 1437 " to the target size at the next full GC rather than requiring" \ 1438 " smaller steps during multiple full GCs.") \ 1439 \ 1440 product(intx, SoftRefLRUPolicyMSPerMB, 1000, \ 1441 "Number of milliseconds per MB of free space in the heap") \ 1442 range(0, max_intx) \ 1443 constraint(SoftRefLRUPolicyMSPerMBConstraintFunc,AfterMemoryInit) \ 1444 \ 1445 product(size_t, MinHeapDeltaBytes, ScaleForWordSize(128*K), \ 1446 "The minimum change in heap space due to GC (in bytes)") \ 1447 range(0, max_uintx) \ 1448 \ 1449 product(size_t, MinMetaspaceExpansion, ScaleForWordSize(256*K), \ 1450 "The minimum expansion of Metaspace (in bytes)") \ 1451 range(0, max_uintx) \ 1452 \ 1453 product(uintx, MaxMetaspaceFreeRatio, 70, \ 1454 "The maximum percentage of Metaspace free after GC to avoid " \ 1455 "shrinking") \ 1456 range(0, 100) \ 1457 constraint(MaxMetaspaceFreeRatioConstraintFunc,AfterErgo) \ 1458 \ 1459 product(uintx, MinMetaspaceFreeRatio, 40, \ 1460 "The minimum percentage of Metaspace free after GC to avoid " \ 1461 "expansion") \ 1462 range(0, 99) \ 1463 constraint(MinMetaspaceFreeRatioConstraintFunc,AfterErgo) \ 1464 \ 1465 product(size_t, MaxMetaspaceExpansion, ScaleForWordSize(4*M), \ 1466 "The maximum expansion of Metaspace without full GC (in bytes)") \ 1467 range(0, max_uintx) \ 1468 \ 1469 /* stack parameters */ \ 1470 product_pd(intx, StackYellowPages, \ 1471 "Number of yellow zone (recoverable overflows) pages of size " \ 1472 "4KB. If pages are bigger yellow zone is aligned up.") \ 1473 range(MIN_STACK_YELLOW_PAGES, (DEFAULT_STACK_YELLOW_PAGES+5)) \ 1474 \ 1475 product_pd(intx, StackRedPages, \ 1476 "Number of red zone (unrecoverable overflows) pages of size " \ 1477 "4KB. If pages are bigger red zone is aligned up.") \ 1478 range(MIN_STACK_RED_PAGES, (DEFAULT_STACK_RED_PAGES+2)) \ 1479 \ 1480 product_pd(intx, StackReservedPages, \ 1481 "Number of reserved zone (reserved to annotated methods) pages" \ 1482 " of size 4KB. If pages are bigger reserved zone is aligned up.") \ 1483 range(MIN_STACK_RESERVED_PAGES, (DEFAULT_STACK_RESERVED_PAGES+10))\ 1484 \ 1485 product(bool, RestrictReservedStack, true, \ 1486 "Restrict @ReservedStackAccess to trusted classes") \ 1487 \ 1488 /* greater stack shadow pages can't generate instruction to bang stack */ \ 1489 product_pd(intx, StackShadowPages, \ 1490 "Number of shadow zone (for overflow checking) pages of size " \ 1491 "4KB. If pages are bigger shadow zone is aligned up. " \ 1492 "This should exceed the depth of the VM and native call stack.") \ 1493 range(MIN_STACK_SHADOW_PAGES, (DEFAULT_STACK_SHADOW_PAGES+30)) \ 1494 \ 1495 product_pd(intx, ThreadStackSize, \ 1496 "Thread Stack Size (in Kbytes)") \ 1497 range(0, 1 * M) \ 1498 \ 1499 product_pd(intx, VMThreadStackSize, \ 1500 "Non-Java Thread Stack Size (in Kbytes)") \ 1501 range(0, max_intx/(1 * K)) \ 1502 \ 1503 product_pd(intx, CompilerThreadStackSize, \ 1504 "Compiler Thread Stack Size (in Kbytes)") \ 1505 range(0, max_intx/(1 * K)) \ 1506 \ 1507 develop_pd(size_t, JVMInvokeMethodSlack, \ 1508 "Stack space (bytes) required for JVM_InvokeMethod to complete") \ 1509 \ 1510 /* code cache parameters */ \ 1511 product_pd(uintx, CodeCacheSegmentSize, EXPERIMENTAL, \ 1512 "Code cache segment size (in bytes) - smallest unit of " \ 1513 "allocation") \ 1514 range(1, 1024) \ 1515 constraint(CodeCacheSegmentSizeConstraintFunc, AfterErgo) \ 1516 \ 1517 product_pd(intx, CodeEntryAlignment, EXPERIMENTAL, \ 1518 "Code entry alignment for generated code (in bytes)") \ 1519 constraint(CodeEntryAlignmentConstraintFunc, AfterErgo) \ 1520 \ 1521 product_pd(intx, OptoLoopAlignment, \ 1522 "Align inner loops to zero relative to this modulus") \ 1523 range(1, 128) \ 1524 constraint(OptoLoopAlignmentConstraintFunc, AfterErgo) \ 1525 \ 1526 product_pd(uintx, InitialCodeCacheSize, \ 1527 "Initial code cache size (in bytes)") \ 1528 constraint(VMPageSizeConstraintFunc, AtParse) \ 1529 \ 1530 develop_pd(uintx, CodeCacheMinimumUseSpace, \ 1531 "Minimum code cache size (in bytes) required to start VM.") \ 1532 range(0, max_uintx) \ 1533 \ 1534 product(bool, SegmentedCodeCache, false, \ 1535 "Use a segmented code cache") \ 1536 \ 1537 product_pd(uintx, ReservedCodeCacheSize, \ 1538 "Reserved code cache size (in bytes) - maximum code cache size") \ 1539 constraint(VMPageSizeConstraintFunc, AtParse) \ 1540 \ 1541 product_pd(uintx, NonProfiledCodeHeapSize, \ 1542 "Size of code heap with non-profiled methods (in bytes)") \ 1543 range(0, max_uintx) \ 1544 \ 1545 product_pd(uintx, ProfiledCodeHeapSize, \ 1546 "Size of code heap with profiled methods (in bytes)") \ 1547 range(0, max_uintx) \ 1548 \ 1549 product_pd(uintx, NonNMethodCodeHeapSize, \ 1550 "Size of code heap with non-nmethods (in bytes)") \ 1551 constraint(VMPageSizeConstraintFunc, AtParse) \ 1552 \ 1553 product_pd(uintx, CodeCacheExpansionSize, \ 1554 "Code cache expansion size (in bytes)") \ 1555 range(32*K, max_uintx) \ 1556 \ 1557 product_pd(uintx, CodeCacheMinBlockLength, DIAGNOSTIC, \ 1558 "Minimum number of segments in a code cache block") \ 1559 range(1, 100) \ 1560 \ 1561 notproduct(bool, ExitOnFullCodeCache, false, \ 1562 "Exit the VM if we fill the code cache") \ 1563 \ 1564 product(bool, UseCodeCacheFlushing, true, \ 1565 "Remove cold/old nmethods from the code cache") \ 1566 \ 1567 product(double, SweeperThreshold, 15.0, \ 1568 "Threshold when a code cache unloading GC is invoked." \ 1569 "Value is percentage of ReservedCodeCacheSize.") \ 1570 range(0.0, 100.0) \ 1571 \ 1572 product(uintx, StartAggressiveSweepingAt, 10, \ 1573 "Start aggressive sweeping if X[%] of the code cache is free." \ 1574 "Segmented code cache: X[%] of the non-profiled heap." \ 1575 "Non-segmented code cache: X[%] of the total code cache") \ 1576 range(0, 100) \ 1577 \ 1578 /* interpreter debugging */ \ 1579 develop(intx, BinarySwitchThreshold, 5, \ 1580 "Minimal number of lookupswitch entries for rewriting to binary " \ 1581 "switch") \ 1582 \ 1583 develop(intx, StopInterpreterAt, 0, \ 1584 "Stop interpreter execution at specified bytecode number") \ 1585 \ 1586 develop(intx, TraceBytecodesAt, 0, \ 1587 "Trace bytecodes starting with specified bytecode number") \ 1588 \ 1589 /* Priorities */ \ 1590 product_pd(bool, UseThreadPriorities, "Use native thread priorities") \ 1591 \ 1592 product(int, ThreadPriorityPolicy, 0, \ 1593 "0 : Normal. "\ 1594 " VM chooses priorities that are appropriate for normal "\ 1595 " applications. "\ 1596 " On Windows applications are allowed to use higher native "\ 1597 " priorities. However, with ThreadPriorityPolicy=0, VM will "\ 1598 " not use the highest possible native priority, "\ 1599 " THREAD_PRIORITY_TIME_CRITICAL, as it may interfere with "\ 1600 " system threads. On Linux thread priorities are ignored "\ 1601 " because the OS does not support static priority in "\ 1602 " SCHED_OTHER scheduling class which is the only choice for "\ 1603 " non-root, non-realtime applications. "\ 1604 "1 : Aggressive. "\ 1605 " Java thread priorities map over to the entire range of "\ 1606 " native thread priorities. Higher Java thread priorities map "\ 1607 " to higher native thread priorities. This policy should be "\ 1608 " used with care, as sometimes it can cause performance "\ 1609 " degradation in the application and/or the entire system. On "\ 1610 " Linux/BSD/macOS this policy requires root privilege or an "\ 1611 " extended capability.") \ 1612 range(0, 1) \ 1613 \ 1614 product(bool, ThreadPriorityVerbose, false, \ 1615 "Print priority changes") \ 1616 \ 1617 product(int, CompilerThreadPriority, -1, \ 1618 "The native priority at which compiler threads should run " \ 1619 "(-1 means no change)") \ 1620 range(min_jint, max_jint) \ 1621 \ 1622 product(int, VMThreadPriority, -1, \ 1623 "The native priority at which the VM thread should run " \ 1624 "(-1 means no change)") \ 1625 range(-1, 127) \ 1626 \ 1627 product(int, JavaPriority1_To_OSPriority, -1, \ 1628 "Map Java priorities to OS priorities") \ 1629 range(-1, 127) \ 1630 \ 1631 product(int, JavaPriority2_To_OSPriority, -1, \ 1632 "Map Java priorities to OS priorities") \ 1633 range(-1, 127) \ 1634 \ 1635 product(int, JavaPriority3_To_OSPriority, -1, \ 1636 "Map Java priorities to OS priorities") \ 1637 range(-1, 127) \ 1638 \ 1639 product(int, JavaPriority4_To_OSPriority, -1, \ 1640 "Map Java priorities to OS priorities") \ 1641 range(-1, 127) \ 1642 \ 1643 product(int, JavaPriority5_To_OSPriority, -1, \ 1644 "Map Java priorities to OS priorities") \ 1645 range(-1, 127) \ 1646 \ 1647 product(int, JavaPriority6_To_OSPriority, -1, \ 1648 "Map Java priorities to OS priorities") \ 1649 range(-1, 127) \ 1650 \ 1651 product(int, JavaPriority7_To_OSPriority, -1, \ 1652 "Map Java priorities to OS priorities") \ 1653 range(-1, 127) \ 1654 \ 1655 product(int, JavaPriority8_To_OSPriority, -1, \ 1656 "Map Java priorities to OS priorities") \ 1657 range(-1, 127) \ 1658 \ 1659 product(int, JavaPriority9_To_OSPriority, -1, \ 1660 "Map Java priorities to OS priorities") \ 1661 range(-1, 127) \ 1662 \ 1663 product(int, JavaPriority10_To_OSPriority,-1, \ 1664 "Map Java priorities to OS priorities") \ 1665 range(-1, 127) \ 1666 \ 1667 product(bool, UseCriticalJavaThreadPriority, false, EXPERIMENTAL, \ 1668 "Java thread priority 10 maps to critical scheduling priority") \ 1669 \ 1670 product(bool, UseCriticalCompilerThreadPriority, false, EXPERIMENTAL, \ 1671 "Compiler thread(s) run at critical scheduling priority") \ 1672 \ 1673 develop(intx, NewCodeParameter, 0, \ 1674 "Testing Only: Create a dedicated integer parameter before " \ 1675 "putback") \ 1676 \ 1677 /* new oopmap storage allocation */ \ 1678 develop(intx, MinOopMapAllocation, 8, \ 1679 "Minimum number of OopMap entries in an OopMapSet") \ 1680 \ 1681 /* recompilation */ \ 1682 product_pd(intx, CompileThreshold, \ 1683 "number of interpreted method invocations before (re-)compiling") \ 1684 constraint(CompileThresholdConstraintFunc, AfterErgo) \ 1685 \ 1686 product_pd(bool, TieredCompilation, \ 1687 "Enable tiered compilation") \ 1688 \ 1689 /* Properties for Java libraries */ \ 1690 \ 1691 product(uint64_t, MaxDirectMemorySize, 0, \ 1692 "Maximum total size of NIO direct-buffer allocations. " \ 1693 "Ignored if not explicitly set.") \ 1694 range(0, max_jlong) \ 1695 \ 1696 /* Flags used for temporary code during development */ \ 1697 \ 1698 product(bool, UseNewCode, false, DIAGNOSTIC, \ 1699 "Testing Only: Use the new version while testing") \ 1700 \ 1701 product(bool, UseNewCode2, false, DIAGNOSTIC, \ 1702 "Testing Only: Use the new version while testing") \ 1703 \ 1704 product(bool, UseNewCode3, false, DIAGNOSTIC, \ 1705 "Testing Only: Use the new version while testing") \ 1706 \ 1707 notproduct(bool, UseDebuggerErgo, false, \ 1708 "Debugging Only: Adjust the VM to be more debugger-friendly. " \ 1709 "Turns on the other UseDebuggerErgo* flags") \ 1710 \ 1711 notproduct(bool, UseDebuggerErgo1, false, \ 1712 "Debugging Only: Enable workarounds for debugger induced " \ 1713 "os::processor_id() >= os::processor_count() problems") \ 1714 \ 1715 notproduct(bool, UseDebuggerErgo2, false, \ 1716 "Debugging Only: Limit the number of spawned JVM threads") \ 1717 \ 1718 notproduct(bool, EnableJVMTIStackDepthAsserts, true, \ 1719 "Enable JVMTI asserts related to stack depth checks") \ 1720 \ 1721 /* flags for performance data collection */ \ 1722 \ 1723 product(bool, UsePerfData, true, \ 1724 "Flag to disable jvmstat instrumentation for performance testing "\ 1725 "and problem isolation purposes") \ 1726 \ 1727 product(bool, PerfDataSaveToFile, false, \ 1728 "Save PerfData memory to hsperfdata_<pid> file on exit") \ 1729 \ 1730 product(ccstr, PerfDataSaveFile, nullptr, \ 1731 "Save PerfData memory to the specified absolute pathname. " \ 1732 "The string %p in the file name (if present) " \ 1733 "will be replaced by pid") \ 1734 \ 1735 product(intx, PerfDataSamplingInterval, 50, \ 1736 "Data sampling interval (in milliseconds)") \ 1737 range(PeriodicTask::min_interval, max_jint) \ 1738 constraint(PerfDataSamplingIntervalFunc, AfterErgo) \ 1739 \ 1740 product(bool, PerfDisableSharedMem, false, \ 1741 "Store performance data in standard memory") \ 1742 \ 1743 product(int, PerfDataMemorySize, 32*K, \ 1744 "Size of performance data memory region. Will be rounded " \ 1745 "up to a multiple of the native os page size.") \ 1746 range(128, 32*64*K) \ 1747 \ 1748 product(int, PerfMaxStringConstLength, 1024, \ 1749 "Maximum PerfStringConstant string length before truncation") \ 1750 range(32, 32*K) \ 1751 \ 1752 product(bool, PerfAllowAtExitRegistration, false, \ 1753 "Allow registration of atexit() methods") \ 1754 \ 1755 product(bool, PerfBypassFileSystemCheck, false, \ 1756 "Bypass Win32 file system criteria checks (Windows Only)") \ 1757 \ 1758 product(int, UnguardOnExecutionViolation, 0, \ 1759 "Unguard page and retry on no-execute fault (Win32 only) " \ 1760 "0=off, 1=conservative, 2=aggressive") \ 1761 range(0, 2) \ 1762 \ 1763 /* Serviceability Support */ \ 1764 \ 1765 product(bool, ManagementServer, false, \ 1766 "Create JMX Management Server") \ 1767 \ 1768 product(bool, DisableAttachMechanism, false, \ 1769 "Disable mechanism that allows tools to attach to this VM") \ 1770 \ 1771 product(bool, StartAttachListener, false, \ 1772 "Always start Attach Listener at VM startup") \ 1773 \ 1774 product(bool, EnableDynamicAgentLoading, true, \ 1775 "Allow tools to load agents with the attach mechanism") \ 1776 \ 1777 product(bool, PrintConcurrentLocks, false, MANAGEABLE, \ 1778 "Print java.util.concurrent locks in thread dump") \ 1779 \ 1780 product(bool, PrintMethodHandleStubs, false, DIAGNOSTIC, \ 1781 "Print generated stub code for method handles") \ 1782 \ 1783 product(bool, VerifyMethodHandles, trueInDebug, DIAGNOSTIC, \ 1784 "perform extra checks when constructing method handles") \ 1785 \ 1786 product(bool, ShowHiddenFrames, false, DIAGNOSTIC, \ 1787 "show method handle implementation frames (usually hidden)") \ 1788 \ 1789 product(bool, ShowCarrierFrames, false, DIAGNOSTIC, \ 1790 "show virtual threads' carrier frames in exceptions") \ 1791 \ 1792 product(bool, TrustFinalNonStaticFields, false, EXPERIMENTAL, \ 1793 "trust final non-static declarations for constant folding") \ 1794 \ 1795 product(bool, FoldStableValues, true, DIAGNOSTIC, \ 1796 "Optimize loads from stable fields (marked w/ @Stable)") \ 1797 \ 1798 product(int, UseBootstrapCallInfo, 1, DIAGNOSTIC, \ 1799 "0: when resolving InDy or ConDy, force all BSM arguments to be " \ 1800 "resolved before the bootstrap method is called; 1: when a BSM " \ 1801 "that may accept a BootstrapCallInfo is detected, use that API " \ 1802 "to pass BSM arguments, which allows the BSM to delay their " \ 1803 "resolution; 2+: stress test the BCI API by calling more BSMs " \ 1804 "via that API, instead of with the eagerly-resolved array.") \ 1805 \ 1806 product(bool, PauseAtStartup, false, DIAGNOSTIC, \ 1807 "Causes the VM to pause at startup time and wait for the pause " \ 1808 "file to be removed (default: ./vm.paused.<pid>)") \ 1809 \ 1810 product(ccstr, PauseAtStartupFile, nullptr, DIAGNOSTIC, \ 1811 "The file to create and for whose removal to await when pausing " \ 1812 "at startup. (default: ./vm.paused.<pid>)") \ 1813 \ 1814 product(bool, PauseAtExit, false, DIAGNOSTIC, \ 1815 "Pause and wait for keypress on exit if a debugger is attached") \ 1816 \ 1817 product(bool, DTraceMethodProbes, false, \ 1818 "Enable dtrace tool probes for method-entry and method-exit") \ 1819 \ 1820 product(bool, DTraceAllocProbes, false, \ 1821 "Enable dtrace tool probes for object allocation") \ 1822 \ 1823 product(bool, DTraceMonitorProbes, false, \ 1824 "Enable dtrace tool probes for monitor events") \ 1825 \ 1826 product(bool, RelaxAccessControlCheck, false, \ 1827 "Relax the access control checks in the verifier") \ 1828 \ 1829 product(uintx, StringTableSize, defaultStringTableSize, \ 1830 "Number of buckets in the interned String table " \ 1831 "(will be rounded to nearest higher power of 2)") \ 1832 range(minimumStringTableSize, 16777216ul /* 2^24 */) \ 1833 \ 1834 product(uintx, SymbolTableSize, defaultSymbolTableSize, EXPERIMENTAL, \ 1835 "Number of buckets in the JVM internal Symbol table") \ 1836 range(minimumSymbolTableSize, 16777216ul /* 2^24 */) \ 1837 \ 1838 product(bool, UseStringDeduplication, false, \ 1839 "Use string deduplication") \ 1840 \ 1841 product(uint, StringDeduplicationAgeThreshold, 3, \ 1842 "A string must reach this age (or be promoted to an old region) " \ 1843 "to be considered for deduplication") \ 1844 range(1, markWord::max_age) \ 1845 \ 1846 product(size_t, StringDeduplicationInitialTableSize, 500, EXPERIMENTAL, \ 1847 "Approximate initial number of buckets in the table") \ 1848 range(1, 1 * G) \ 1849 \ 1850 product(double, StringDeduplicationGrowTableLoad, 14.0, EXPERIMENTAL, \ 1851 "Entries per bucket above which the table should be expanded") \ 1852 range(0.1, 1000.0) \ 1853 \ 1854 product(double, StringDeduplicationShrinkTableLoad, 1.0, EXPERIMENTAL, \ 1855 "Entries per bucket below which the table should be shrunk") \ 1856 range(0.01, 100.0) \ 1857 \ 1858 product(double, StringDeduplicationTargetTableLoad, 7.0, EXPERIMENTAL, \ 1859 "Desired entries per bucket when resizing the table") \ 1860 range(0.01, 1000.0) \ 1861 \ 1862 product(size_t, StringDeduplicationCleanupDeadMinimum, 100, EXPERIMENTAL, \ 1863 "Minimum number of dead table entries for cleaning the table") \ 1864 \ 1865 product(int, StringDeduplicationCleanupDeadPercent, 5, EXPERIMENTAL, \ 1866 "Minimum percentage of dead table entries for cleaning the table") \ 1867 range(1, 100) \ 1868 \ 1869 product(bool, StringDeduplicationResizeALot, false, DIAGNOSTIC, \ 1870 "Force more frequent table resizing") \ 1871 \ 1872 product(uint64_t, StringDeduplicationHashSeed, 0, DIAGNOSTIC, \ 1873 "Seed for the table hashing function; 0 requests computed seed") \ 1874 \ 1875 product(bool, WhiteBoxAPI, false, DIAGNOSTIC, \ 1876 "Enable internal testing APIs") \ 1877 \ 1878 product(size_t, ArrayAllocatorMallocLimit, SIZE_MAX, EXPERIMENTAL, \ 1879 "Allocation less than this value will be allocated " \ 1880 "using malloc. Larger allocations will use mmap.") \ 1881 \ 1882 product(bool, AlwaysAtomicAccesses, false, EXPERIMENTAL, \ 1883 "Accesses to all variables should always be atomic") \ 1884 \ 1885 product(bool, UseUnalignedAccesses, false, DIAGNOSTIC, \ 1886 "Use unaligned memory accesses in Unsafe") \ 1887 \ 1888 product_pd(bool, PreserveFramePointer, \ 1889 "Use the FP register for holding the frame pointer " \ 1890 "and not as a general purpose register.") \ 1891 \ 1892 product(size_t, AsyncLogBufferSize, 2*M, \ 1893 "Memory budget (in bytes) for the buffer of Asynchronous " \ 1894 "Logging (-Xlog:async).") \ 1895 range(100*K, 50*M) \ 1896 \ 1897 product(bool, CheckIntrinsics, true, DIAGNOSTIC, \ 1898 "When a class C is loaded, check that " \ 1899 "(1) all intrinsics defined by the VM for class C are present "\ 1900 "in the loaded class file and are marked with the " \ 1901 "@IntrinsicCandidate annotation, that " \ 1902 "(2) there is an intrinsic registered for all loaded methods " \ 1903 "that are annotated with the @IntrinsicCandidate annotation, " \ 1904 "and that " \ 1905 "(3) no orphan methods exist for class C (i.e., methods for " \ 1906 "which the VM declares an intrinsic but that are not declared "\ 1907 "in the loaded class C. " \ 1908 "Check (3) is available only in debug builds.") \ 1909 \ 1910 product_pd(intx, InitArrayShortSize, DIAGNOSTIC, \ 1911 "Threshold small size (in bytes) for clearing arrays. " \ 1912 "Anything this size or smaller may get converted to discrete " \ 1913 "scalar stores.") \ 1914 range(0, max_intx) \ 1915 constraint(InitArrayShortSizeConstraintFunc, AfterErgo) \ 1916 \ 1917 product(ccstr, AllocateHeapAt, nullptr, \ 1918 "Path to the directory where a temporary file will be created " \ 1919 "to use as the backing store for Java Heap.") \ 1920 \ 1921 product_pd(bool, VMContinuations, EXPERIMENTAL, \ 1922 "Enable VM continuations support") \ 1923 \ 1924 develop(bool, LoomDeoptAfterThaw, false, \ 1925 "Deopt stack after thaw") \ 1926 \ 1927 develop(bool, LoomVerifyAfterThaw, false, \ 1928 "Verify stack after thaw") \ 1929 \ 1930 develop(bool, VerifyContinuations, false, \ 1931 "Verify continuation consistency") \ 1932 \ 1933 develop(bool, UseContinuationFastPath, true, \ 1934 "Use fast-path frame walking in continuations") \ 1935 \ 1936 develop(int, VerifyMetaspaceInterval, DEBUG_ONLY(500) NOT_DEBUG(0), \ 1937 "Run periodic metaspace verifications (0 - none, " \ 1938 "1 - always, >1 every nth interval)") \ 1939 \ 1940 product(bool, ShowRegistersOnAssert, true, DIAGNOSTIC, \ 1941 "On internal errors, include registers in error report.") \ 1942 \ 1943 product(bool, UseSwitchProfiling, true, DIAGNOSTIC, \ 1944 "leverage profiling for table/lookup switch") \ 1945 \ 1946 develop(bool, TraceMemoryWriteback, false, \ 1947 "Trace memory writeback operations") \ 1948 \ 1949 JFR_ONLY(product(bool, FlightRecorder, false, \ 1950 "(Deprecated) Enable Flight Recorder")) \ 1951 \ 1952 JFR_ONLY(product(ccstr, FlightRecorderOptions, nullptr, \ 1953 "Flight Recorder options")) \ 1954 \ 1955 JFR_ONLY(product(ccstr, StartFlightRecording, nullptr, \ 1956 "Start flight recording with options")) \ 1957 \ 1958 product(bool, UseFastUnorderedTimeStamps, false, EXPERIMENTAL, \ 1959 "Use platform unstable time where supported for timestamps only") \ 1960 \ 1961 product(bool, UseEmptySlotsInSupers, true, \ 1962 "Allow allocating fields in empty slots of super-classes") \ 1963 \ 1964 product(bool, DeoptimizeNMethodBarriersALot, false, DIAGNOSTIC, \ 1965 "Make nmethod barriers deoptimise a lot.") \ 1966 \ 1967 develop(bool, VerifyCrossModifyFence, \ 1968 false AARCH64_ONLY(DEBUG_ONLY(||true)), \ 1969 "Mark all threads after a safepoint, and clear on a modify " \ 1970 "fence. Add cleanliness checks.") \ 1971 \ 1972 product(int, LockingMode, LM_LEGACY, EXPERIMENTAL, \ 1973 "Select locking mode: " \ 1974 "0: monitors only (LM_MONITOR), " \ 1975 "1: monitors & legacy stack-locking (LM_LEGACY, default), " \ 1976 "2: monitors & new lightweight locking (LM_LIGHTWEIGHT)") \ 1977 range(0, 2) \ 1978 \ 1979 product(uint, TrimNativeHeapInterval, 0, \ 1980 "Interval, in ms, at which the JVM will trim the native heap if " \ 1981 "the platform supports that. Lower values will reclaim memory " \ 1982 "more eagerly at the cost of higher overhead. A value of 0 " \ 1983 "(default) disables native heap trimming.") \ 1984 range(0, UINT_MAX) \ 1985 1986 // end of RUNTIME_FLAGS 1987 1988 DECLARE_FLAGS(LP64_RUNTIME_FLAGS) 1989 DECLARE_ARCH_FLAGS(ARCH_FLAGS) 1990 DECLARE_FLAGS(RUNTIME_FLAGS) 1991 DECLARE_FLAGS(RUNTIME_OS_FLAGS) 1992 1993 #endif // SHARE_RUNTIME_GLOBALS_HPP