1 /* 2 * Copyright (c) 1997, 2023, 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(bool, UseCompactObjectHeaders, false, EXPERIMENTAL, \ 134 "Use 64-bit object headers instead of 96-bit headers") \ 135 \ 136 product(int, ObjectAlignmentInBytes, 8, \ 137 "Default object alignment in bytes, 8 is minimum") \ 138 range(8, 256) \ 139 constraint(ObjectAlignmentInBytesConstraintFunc, AtParse) 140 141 #else 142 // !_LP64 143 144 #define LP64_RUNTIME_FLAGS(develop, \ 145 develop_pd, \ 146 product, \ 147 product_pd, \ 148 notproduct, \ 149 range, \ 150 constraint) 151 const bool UseCompressedOops = false; 152 const bool UseCompressedClassPointers = false; 153 const bool UseCompactObjectHeaders = false; 154 const int ObjectAlignmentInBytes = 8; 155 156 #endif // _LP64 157 158 #define RUNTIME_FLAGS(develop, \ 159 develop_pd, \ 160 product, \ 161 product_pd, \ 162 notproduct, \ 163 range, \ 164 constraint) \ 165 \ 166 notproduct(bool, CheckCompressedOops, true, \ 167 "Generate checks in encoding/decoding code in debug VM") \ 168 \ 169 product(uintx, HeapSearchSteps, 3 PPC64_ONLY(+17), \ 170 "Heap allocation steps through preferred address regions to find" \ 171 " where it can allocate the heap. Number of steps to take per " \ 172 "region.") \ 173 range(1, max_uintx) \ 174 \ 175 product(uint, HandshakeTimeout, 0, DIAGNOSTIC, \ 176 "If nonzero set a timeout in milliseconds for handshakes") \ 177 \ 178 product(bool, AlwaysSafeConstructors, false, EXPERIMENTAL, \ 179 "Force safe construction, as if all fields are final.") \ 180 \ 181 product(bool, UnlockDiagnosticVMOptions, trueInDebug, DIAGNOSTIC, \ 182 "Enable normal processing of flags relating to field diagnostics")\ 183 \ 184 product(bool, UnlockExperimentalVMOptions, false, EXPERIMENTAL, \ 185 "Enable normal processing of flags relating to experimental " \ 186 "features") \ 187 \ 188 product(bool, JavaMonitorsInStackTrace, true, \ 189 "Print information about Java monitor locks when the stacks are " \ 190 "dumped") \ 191 \ 192 product_pd(bool, UseLargePages, \ 193 "Use large page memory") \ 194 \ 195 product_pd(bool, UseLargePagesIndividualAllocation, \ 196 "Allocate large pages individually for better affinity") \ 197 \ 198 develop(bool, LargePagesIndividualAllocationInjectError, false, \ 199 "Fail large pages individual allocation") \ 200 \ 201 product(bool, UseNUMA, false, \ 202 "Use NUMA if available") \ 203 \ 204 product(bool, UseNUMAInterleaving, false, \ 205 "Interleave memory across NUMA nodes if available") \ 206 \ 207 product(size_t, NUMAInterleaveGranularity, 2*M, \ 208 "Granularity to use for NUMA interleaving on Windows OS") \ 209 constraint(NUMAInterleaveGranularityConstraintFunc, AtParse) \ 210 \ 211 product(uintx, NUMAChunkResizeWeight, 20, \ 212 "Percentage (0-100) used to weight the current sample when " \ 213 "computing exponentially decaying average for " \ 214 "AdaptiveNUMAChunkSizing") \ 215 range(0, 100) \ 216 \ 217 product(size_t, NUMASpaceResizeRate, 1*G, \ 218 "Do not reallocate more than this amount per collection") \ 219 range(0, max_uintx) \ 220 \ 221 product(bool, UseAdaptiveNUMAChunkSizing, true, \ 222 "Enable adaptive chunk sizing for NUMA") \ 223 \ 224 product(bool, NUMAStats, false, \ 225 "Print NUMA stats in detailed heap information") \ 226 \ 227 product(uintx, NUMAPageScanRate, 256, \ 228 "Maximum number of pages to include in the page scan procedure") \ 229 range(0, max_uintx) \ 230 \ 231 product(bool, UseAES, false, \ 232 "Control whether AES instructions are used when available") \ 233 \ 234 product(bool, UseFMA, false, \ 235 "Control whether FMA instructions are used when available") \ 236 \ 237 product(bool, UseSHA, false, \ 238 "Control whether SHA instructions are used when available") \ 239 \ 240 product(bool, UseGHASHIntrinsics, false, DIAGNOSTIC, \ 241 "Use intrinsics for GHASH versions of crypto") \ 242 \ 243 product(bool, UseBASE64Intrinsics, false, \ 244 "Use intrinsics for java.util.Base64") \ 245 \ 246 product(bool, UsePoly1305Intrinsics, false, DIAGNOSTIC, \ 247 "Use intrinsics for sun.security.util.math.intpoly") \ 248 \ 249 product(size_t, LargePageSizeInBytes, 0, \ 250 "Maximum large page size used (0 will use the default large " \ 251 "page size for the environment as the maximum)") \ 252 range(0, max_uintx) \ 253 \ 254 product(size_t, LargePageHeapSizeThreshold, 128*M, \ 255 "Use large pages if maximum heap is at least this big") \ 256 range(0, max_uintx) \ 257 \ 258 product(bool, ForceTimeHighResolution, false, \ 259 "Using high time resolution (for Win32 only)") \ 260 \ 261 develop(bool, TracePcPatching, false, \ 262 "Trace usage of frame::patch_pc") \ 263 \ 264 develop(bool, TraceRelocator, false, \ 265 "Trace the bytecode relocator") \ 266 \ 267 \ 268 product(bool, SafepointALot, false, DIAGNOSTIC, \ 269 "Generate a lot of safepoints. This works with " \ 270 "GuaranteedSafepointInterval") \ 271 \ 272 product(bool, HandshakeALot, false, DIAGNOSTIC, \ 273 "Generate a lot of handshakes. This works with " \ 274 "GuaranteedSafepointInterval") \ 275 \ 276 product_pd(bool, BackgroundCompilation, \ 277 "A thread requesting compilation is not blocked during " \ 278 "compilation") \ 279 \ 280 product(bool, MethodFlushing, true, \ 281 "Reclamation of compiled methods") \ 282 \ 283 develop(bool, VerifyStack, false, \ 284 "Verify stack of each thread when it is entering a runtime call") \ 285 \ 286 product(bool, ForceUnreachable, false, DIAGNOSTIC, \ 287 "Make all non code cache addresses to be unreachable by " \ 288 "forcing use of 64bit literal fixups") \ 289 \ 290 develop(bool, TraceDerivedPointers, false, \ 291 "Trace traversal of derived pointers on stack") \ 292 \ 293 notproduct(bool, TraceCodeBlobStacks, false, \ 294 "Trace stack-walk of codeblobs") \ 295 \ 296 notproduct(bool, PrintRewrites, false, \ 297 "Print methods that are being rewritten") \ 298 \ 299 product(bool, UseInlineCaches, true, \ 300 "Use Inline Caches for virtual calls ") \ 301 \ 302 product(bool, InlineArrayCopy, true, DIAGNOSTIC, \ 303 "Inline arraycopy native that is known to be part of " \ 304 "base library DLL") \ 305 \ 306 product(bool, InlineObjectHash, true, DIAGNOSTIC, \ 307 "Inline Object::hashCode() native that is known to be part " \ 308 "of base library DLL") \ 309 \ 310 product(bool, InlineNatives, true, DIAGNOSTIC, \ 311 "Inline natives that are known to be part of base library DLL") \ 312 \ 313 product(bool, InlineMathNatives, true, DIAGNOSTIC, \ 314 "Inline SinD, CosD, etc.") \ 315 \ 316 product(bool, InlineClassNatives, true, DIAGNOSTIC, \ 317 "Inline Class.isInstance, etc") \ 318 \ 319 product(bool, InlineThreadNatives, true, DIAGNOSTIC, \ 320 "Inline Thread.currentThread, etc") \ 321 \ 322 product(bool, InlineUnsafeOps, true, DIAGNOSTIC, \ 323 "Inline memory ops (native methods) from Unsafe") \ 324 \ 325 product(bool, UseAESIntrinsics, false, DIAGNOSTIC, \ 326 "Use intrinsics for AES versions of crypto") \ 327 \ 328 product(bool, UseAESCTRIntrinsics, false, DIAGNOSTIC, \ 329 "Use intrinsics for the paralleled version of AES/CTR crypto") \ 330 \ 331 product(bool, UseChaCha20Intrinsics, false, DIAGNOSTIC, \ 332 "Use intrinsics for the vectorized version of ChaCha20") \ 333 \ 334 product(bool, UseMD5Intrinsics, false, DIAGNOSTIC, \ 335 "Use intrinsics for MD5 crypto hash function") \ 336 \ 337 product(bool, UseSHA1Intrinsics, false, DIAGNOSTIC, \ 338 "Use intrinsics for SHA-1 crypto hash function. " \ 339 "Requires that UseSHA is enabled.") \ 340 \ 341 product(bool, UseSHA256Intrinsics, false, DIAGNOSTIC, \ 342 "Use intrinsics for SHA-224 and SHA-256 crypto hash functions. " \ 343 "Requires that UseSHA is enabled.") \ 344 \ 345 product(bool, UseSHA512Intrinsics, false, DIAGNOSTIC, \ 346 "Use intrinsics for SHA-384 and SHA-512 crypto hash functions. " \ 347 "Requires that UseSHA is enabled.") \ 348 \ 349 product(bool, UseSHA3Intrinsics, false, DIAGNOSTIC, \ 350 "Use intrinsics for SHA3 crypto hash function. " \ 351 "Requires that UseSHA is enabled.") \ 352 \ 353 product(bool, UseCRC32Intrinsics, false, DIAGNOSTIC, \ 354 "use intrinsics for java.util.zip.CRC32") \ 355 \ 356 product(bool, UseCRC32CIntrinsics, false, DIAGNOSTIC, \ 357 "use intrinsics for java.util.zip.CRC32C") \ 358 \ 359 product(bool, UseAdler32Intrinsics, false, DIAGNOSTIC, \ 360 "use intrinsics for java.util.zip.Adler32") \ 361 \ 362 product(bool, UseVectorizedMismatchIntrinsic, false, DIAGNOSTIC, \ 363 "Enables intrinsification of ArraysSupport.vectorizedMismatch()") \ 364 \ 365 product(bool, UseVectorizedHashCodeIntrinsic, false, DIAGNOSTIC, \ 366 "Enables intrinsification of ArraysSupport.vectorizedHashCode()") \ 367 \ 368 product(bool, UseCopySignIntrinsic, false, DIAGNOSTIC, \ 369 "Enables intrinsification of Math.copySign") \ 370 \ 371 product(bool, UseSignumIntrinsic, false, DIAGNOSTIC, \ 372 "Enables intrinsification of Math.signum") \ 373 \ 374 product_pd(bool, DelayCompilerStubsGeneration, DIAGNOSTIC, \ 375 "Use Compiler thread for compiler's stubs generation") \ 376 \ 377 product(ccstrlist, DisableIntrinsic, "", DIAGNOSTIC, \ 378 "do not expand intrinsics whose (internal) names appear here") \ 379 constraint(DisableIntrinsicConstraintFunc,AfterErgo) \ 380 \ 381 product(ccstrlist, ControlIntrinsic, "", DIAGNOSTIC, \ 382 "Control intrinsics using a list of +/- (internal) names, " \ 383 "separated by commas") \ 384 constraint(ControlIntrinsicConstraintFunc,AfterErgo) \ 385 \ 386 develop(bool, TraceCallFixup, false, \ 387 "Trace all call fixups") \ 388 \ 389 develop(bool, DeoptimizeALot, false, \ 390 "Deoptimize at every exit from the runtime system") \ 391 \ 392 notproduct(ccstrlist, DeoptimizeOnlyAt, "", \ 393 "A comma separated list of bcis to deoptimize at") \ 394 \ 395 develop(bool, DeoptimizeRandom, false, \ 396 "Deoptimize random frames on random exit from the runtime system")\ 397 \ 398 notproduct(bool, ZombieALot, false, \ 399 "Create non-entrant nmethods at exit from the runtime system") \ 400 \ 401 notproduct(bool, WalkStackALot, false, \ 402 "Trace stack (no print) at every exit from the runtime system") \ 403 \ 404 develop(bool, DeoptimizeObjectsALot, false, \ 405 "For testing purposes concurrent threads revert optimizations " \ 406 "based on escape analysis at intervals given with " \ 407 "DeoptimizeObjectsALotInterval=n. The thread count is given " \ 408 "with DeoptimizeObjectsALotThreadCountSingle and " \ 409 "DeoptimizeObjectsALotThreadCountAll.") \ 410 \ 411 develop(uint64_t, DeoptimizeObjectsALotInterval, 5, \ 412 "Interval for DeoptimizeObjectsALot.") \ 413 range(0, max_jlong) \ 414 \ 415 develop(int, DeoptimizeObjectsALotThreadCountSingle, 1, \ 416 "The number of threads that revert optimizations based on " \ 417 "escape analysis for a single thread if DeoptimizeObjectsALot " \ 418 "is enabled. The target thread is selected round robin." ) \ 419 range(0, max_jint) \ 420 \ 421 develop(int, DeoptimizeObjectsALotThreadCountAll, 1, \ 422 "The number of threads that revert optimizations based on " \ 423 "escape analysis for all threads if DeoptimizeObjectsALot " \ 424 "is enabled." ) \ 425 range(0, max_jint) \ 426 \ 427 notproduct(bool, VerifyLastFrame, false, \ 428 "Verify oops on last frame on entry to VM") \ 429 \ 430 product(bool, SafepointTimeout, false, \ 431 "Time out and warn or fail after SafepointTimeoutDelay " \ 432 "milliseconds if failed to reach safepoint") \ 433 \ 434 product(bool, AbortVMOnSafepointTimeout, false, DIAGNOSTIC, \ 435 "Abort upon failure to reach safepoint (see SafepointTimeout)") \ 436 \ 437 product(bool, AbortVMOnVMOperationTimeout, false, DIAGNOSTIC, \ 438 "Abort upon failure to complete VM operation promptly") \ 439 \ 440 product(intx, AbortVMOnVMOperationTimeoutDelay, 1000, DIAGNOSTIC, \ 441 "Delay in milliseconds for option AbortVMOnVMOperationTimeout") \ 442 range(0, max_intx) \ 443 \ 444 product(bool, MaxFDLimit, true, \ 445 "Bump the number of file descriptors to maximum (Unix only)") \ 446 \ 447 product(bool, LogEvents, true, DIAGNOSTIC, \ 448 "Enable the various ring buffer event logs") \ 449 \ 450 product(int, LogEventsBufferEntries, 20, DIAGNOSTIC, \ 451 "Number of ring buffer event logs") \ 452 range(1, NOT_LP64(1*K) LP64_ONLY(1*M)) \ 453 \ 454 product(bool, BytecodeVerificationRemote, true, DIAGNOSTIC, \ 455 "Enable the Java bytecode verifier for remote classes") \ 456 \ 457 product(bool, BytecodeVerificationLocal, false, DIAGNOSTIC, \ 458 "Enable the Java bytecode verifier for local classes") \ 459 \ 460 develop(bool, VerifyStackAtCalls, false, \ 461 "Verify that the stack pointer is unchanged after calls") \ 462 \ 463 develop(bool, TraceJavaAssertions, false, \ 464 "Trace java language assertions") \ 465 \ 466 notproduct(bool, VerifyCodeCache, false, \ 467 "Verify code cache on memory allocation/deallocation") \ 468 \ 469 develop(bool, ZapResourceArea, trueInDebug, \ 470 "Zap freed resource/arena space") \ 471 \ 472 notproduct(bool, ZapVMHandleArea, trueInDebug, \ 473 "Zap freed VM handle space") \ 474 \ 475 notproduct(bool, ZapStackSegments, trueInDebug, \ 476 "Zap allocated/freed stack segments") \ 477 \ 478 develop(bool, ZapUnusedHeapArea, trueInDebug, \ 479 "Zap unused heap space") \ 480 \ 481 develop(bool, CheckZapUnusedHeapArea, false, \ 482 "Check zapping of unused heap space") \ 483 \ 484 develop(bool, ZapFillerObjects, trueInDebug, \ 485 "Zap filler objects") \ 486 \ 487 product(bool, ExecutingUnitTests, false, \ 488 "Whether the JVM is running unit tests or not") \ 489 \ 490 develop(uint, ErrorHandlerTest, 0, \ 491 "If > 0, provokes an error after VM initialization; the value " \ 492 "determines which error to provoke. See controlled_crash() " \ 493 "in vmError.cpp.") \ 494 range(0, 17) \ 495 \ 496 develop(uint, TestCrashInErrorHandler, 0, \ 497 "If > 0, provokes an error inside VM error handler (a secondary " \ 498 "crash). see controlled_crash() in vmError.cpp") \ 499 range(0, 17) \ 500 \ 501 develop(bool, TestSafeFetchInErrorHandler, false , \ 502 "If true, tests SafeFetch inside error handler.") \ 503 \ 504 develop(bool, TestUnresponsiveErrorHandler, false, \ 505 "If true, simulates an unresponsive error handler.") \ 506 \ 507 develop(bool, Verbose, false, \ 508 "Print additional debugging information from other modes") \ 509 \ 510 develop(bool, PrintMiscellaneous, false, \ 511 "Print uncategorized debugging information (requires +Verbose)") \ 512 \ 513 develop(bool, WizardMode, false, \ 514 "Print much more debugging information") \ 515 \ 516 product(bool, ShowMessageBoxOnError, false, \ 517 "Keep process alive on VM fatal error") \ 518 \ 519 product(bool, CreateCoredumpOnCrash, true, \ 520 "Create core/mini dump on VM fatal error") \ 521 \ 522 product(uint64_t, ErrorLogTimeout, 2 * 60, \ 523 "Timeout, in seconds, to limit the time spent on writing an " \ 524 "error log in case of a crash.") \ 525 range(0, (uint64_t)max_jlong/1000) \ 526 \ 527 product(bool, ErrorLogSecondaryErrorDetails, false, DIAGNOSTIC, \ 528 "If enabled, show details on secondary crashes in the error log") \ 529 \ 530 develop(intx, TraceDwarfLevel, 0, \ 531 "Debug levels for the dwarf parser") \ 532 range(0, 4) \ 533 \ 534 product(bool, SuppressFatalErrorMessage, false, \ 535 "Report NO fatal error message (avoid deadlock)") \ 536 \ 537 product(ccstrlist, OnError, "", \ 538 "Run user-defined commands on fatal error; see VMError.cpp " \ 539 "for examples") \ 540 \ 541 product(ccstrlist, OnOutOfMemoryError, "", \ 542 "Run user-defined commands on first java.lang.OutOfMemoryError " \ 543 "thrown from JVM") \ 544 \ 545 product(bool, HeapDumpBeforeFullGC, false, MANAGEABLE, \ 546 "Dump heap to file before any major stop-the-world GC") \ 547 \ 548 product(bool, HeapDumpAfterFullGC, false, MANAGEABLE, \ 549 "Dump heap to file after any major stop-the-world GC") \ 550 \ 551 product(bool, HeapDumpOnOutOfMemoryError, false, MANAGEABLE, \ 552 "Dump heap to file when java.lang.OutOfMemoryError is thrown " \ 553 "from JVM") \ 554 \ 555 product(ccstr, HeapDumpPath, nullptr, MANAGEABLE, \ 556 "When HeapDumpOnOutOfMemoryError is on, the path (filename or " \ 557 "directory) of the dump file (defaults to java_pid<pid>.hprof " \ 558 "in the working directory)") \ 559 \ 560 product(intx, HeapDumpGzipLevel, 0, MANAGEABLE, \ 561 "When HeapDumpOnOutOfMemoryError is on, the gzip compression " \ 562 "level of the dump file. 0 (the default) disables gzip " \ 563 "compression. Otherwise the level must be between 1 and 9.") \ 564 range(0, 9) \ 565 \ 566 product(ccstr, NativeMemoryTracking, DEBUG_ONLY("summary") NOT_DEBUG("off"), \ 567 "Native memory tracking options") \ 568 \ 569 product(bool, PrintNMTStatistics, false, DIAGNOSTIC, \ 570 "Print native memory tracking summary data if it is on") \ 571 \ 572 product(bool, LogCompilation, false, DIAGNOSTIC, \ 573 "Log compilation activity in detail to LogFile") \ 574 \ 575 product(bool, PrintCompilation, false, \ 576 "Print compilations") \ 577 \ 578 product(intx, RepeatCompilation, 0, DIAGNOSTIC, \ 579 "Repeat compilation without installing code (number of times)") \ 580 range(0, max_jint) \ 581 \ 582 product(bool, PrintExtendedThreadInfo, false, \ 583 "Print more information in thread dump") \ 584 \ 585 product(intx, ScavengeRootsInCode, 2, DIAGNOSTIC, \ 586 "0: do not allow scavengable oops in the code cache; " \ 587 "1: allow scavenging from the code cache; " \ 588 "2: emit as many constants as the compiler can see") \ 589 range(0, 2) \ 590 \ 591 product(bool, AlwaysRestoreFPU, false, \ 592 "Restore the FPU control word after every JNI call (expensive)") \ 593 \ 594 product(bool, PrintCompilation2, false, DIAGNOSTIC, \ 595 "Print additional statistics per compilation") \ 596 \ 597 product(bool, PrintAdapterHandlers, false, DIAGNOSTIC, \ 598 "Print code generated for i2c/c2i adapters") \ 599 \ 600 product(bool, VerifyAdapterCalls, trueInDebug, DIAGNOSTIC, \ 601 "Verify that i2c/c2i adapters are called properly") \ 602 \ 603 develop(bool, VerifyAdapterSharing, false, \ 604 "Verify that the code for shared adapters is the equivalent") \ 605 \ 606 product(bool, PrintAssembly, false, DIAGNOSTIC, \ 607 "Print assembly code (using external disassembler.so)") \ 608 \ 609 product(ccstr, PrintAssemblyOptions, nullptr, DIAGNOSTIC, \ 610 "Print options string passed to disassembler.so") \ 611 \ 612 notproduct(bool, PrintNMethodStatistics, false, \ 613 "Print a summary statistic for the generated nmethods") \ 614 \ 615 product(bool, PrintNMethods, false, DIAGNOSTIC, \ 616 "Print assembly code for nmethods when generated") \ 617 \ 618 product(bool, PrintNativeNMethods, false, DIAGNOSTIC, \ 619 "Print assembly code for native nmethods when generated") \ 620 \ 621 develop(bool, PrintDebugInfo, false, \ 622 "Print debug information for all nmethods when generated") \ 623 \ 624 develop(bool, PrintRelocations, false, \ 625 "Print relocation information for all nmethods when generated") \ 626 \ 627 develop(bool, PrintDependencies, false, \ 628 "Print dependency information for all nmethods when generated") \ 629 \ 630 develop(bool, PrintExceptionHandlers, false, \ 631 "Print exception handler tables for all nmethods when generated") \ 632 \ 633 develop(bool, StressCompiledExceptionHandlers, false, \ 634 "Exercise compiled exception handlers") \ 635 \ 636 develop(bool, InterceptOSException, false, \ 637 "Start debugger when an implicit OS (e.g. null pointer) " \ 638 "exception happens") \ 639 \ 640 product(bool, PrintCodeCache, false, \ 641 "Print the code cache memory usage when exiting") \ 642 \ 643 develop(bool, PrintCodeCache2, false, \ 644 "Print detailed usage information on the code cache when exiting")\ 645 \ 646 product(bool, PrintCodeCacheOnCompilation, false, \ 647 "Print the code cache memory usage each time a method is " \ 648 "compiled") \ 649 \ 650 product(bool, PrintCodeHeapAnalytics, false, DIAGNOSTIC, \ 651 "Print code heap usage statistics on exit and on full condition") \ 652 \ 653 product(bool, PrintStubCode, false, DIAGNOSTIC, \ 654 "Print generated stub code") \ 655 \ 656 product(bool, StackTraceInThrowable, true, \ 657 "Collect backtrace in throwable when exception happens") \ 658 \ 659 product(bool, OmitStackTraceInFastThrow, true, \ 660 "Omit backtraces for some 'hot' exceptions in optimized code") \ 661 \ 662 product(bool, ShowCodeDetailsInExceptionMessages, true, MANAGEABLE, \ 663 "Show exception messages from RuntimeExceptions that contain " \ 664 "snippets of the failing code. Disable this to improve privacy.") \ 665 \ 666 product(bool, PrintWarnings, true, \ 667 "Print JVM warnings to output stream") \ 668 \ 669 product(bool, RegisterFinalizersAtInit, true, \ 670 "Register finalizable objects at end of Object.<init> or " \ 671 "after allocation") \ 672 \ 673 develop(bool, RegisterReferences, true, \ 674 "Tell whether the VM should register soft/weak/final/phantom " \ 675 "references") \ 676 \ 677 develop(bool, PrintCodeCacheExtension, false, \ 678 "Print extension of code cache") \ 679 \ 680 develop(bool, UsePrivilegedStack, true, \ 681 "Enable the security JVM functions") \ 682 \ 683 product(bool, ClassUnloading, true, \ 684 "Do unloading of classes") \ 685 \ 686 product(bool, ClassUnloadingWithConcurrentMark, true, \ 687 "Do unloading of classes with a concurrent marking cycle") \ 688 \ 689 notproduct(bool, PrintSystemDictionaryAtExit, false, \ 690 "Print the system dictionary at exit") \ 691 \ 692 notproduct(bool, PrintClassLoaderDataGraphAtExit, false, \ 693 "Print the class loader data graph at exit") \ 694 \ 695 product(bool, AllowParallelDefineClass, false, \ 696 "Allow parallel defineClass requests for class loaders " \ 697 "registering as parallel capable") \ 698 \ 699 product_pd(bool, DontYieldALot, \ 700 "Throw away obvious excess yield calls") \ 701 \ 702 product(bool, DisablePrimordialThreadGuardPages, false, EXPERIMENTAL, \ 703 "Disable the use of stack guard pages if the JVM is loaded " \ 704 "on the primordial process thread") \ 705 \ 706 product(bool, DoJVMTIVirtualThreadTransitions, true, EXPERIMENTAL, \ 707 "Do JVMTI virtual thread mount/unmount transitions " \ 708 "(disabling this flag implies no JVMTI events are posted)") \ 709 \ 710 /* notice: the max range value here is max_jint, not max_intx */ \ 711 /* because of overflow issue */ \ 712 product(intx, AsyncDeflationInterval, 250, DIAGNOSTIC, \ 713 "Async deflate idle monitors every so many milliseconds when " \ 714 "MonitorUsedDeflationThreshold is exceeded (0 is off).") \ 715 range(0, max_jint) \ 716 \ 717 /* notice: the max range value here is max_jint, not max_intx */ \ 718 /* because of overflow issue */ \ 719 product(intx, GuaranteedAsyncDeflationInterval, 60000, DIAGNOSTIC, \ 720 "Async deflate idle monitors every so many milliseconds even " \ 721 "when MonitorUsedDeflationThreshold is NOT exceeded (0 is off).") \ 722 range(0, max_jint) \ 723 \ 724 product(size_t, AvgMonitorsPerThreadEstimate, 1024, DIAGNOSTIC, \ 725 "Used to estimate a variable ceiling based on number of threads " \ 726 "for use with MonitorUsedDeflationThreshold (0 is off).") \ 727 range(0, max_uintx) \ 728 \ 729 /* notice: the max range value here is max_jint, not max_intx */ \ 730 /* because of overflow issue */ \ 731 product(intx, MonitorDeflationMax, 1000000, DIAGNOSTIC, \ 732 "The maximum number of monitors to deflate, unlink and delete " \ 733 "at one time (minimum is 1024).") \ 734 range(1024, max_jint) \ 735 \ 736 product(int, MonitorUsedDeflationThreshold, 90, DIAGNOSTIC, \ 737 "Percentage of used monitors before triggering deflation (0 is " \ 738 "off). The check is performed on GuaranteedSafepointInterval, " \ 739 "AsyncDeflationInterval or GuaranteedAsyncDeflationInterval, " \ 740 "whichever is lower.") \ 741 range(0, 100) \ 742 \ 743 product(uintx, NoAsyncDeflationProgressMax, 3, DIAGNOSTIC, \ 744 "Max number of no progress async deflation attempts to tolerate " \ 745 "before adjusting the in_use_list_ceiling up (0 is off).") \ 746 range(0, max_uintx) \ 747 \ 748 product(intx, hashCode, 5, EXPERIMENTAL, \ 749 "(Unstable) select hashCode generation algorithm") \ 750 \ 751 product(bool, ReduceSignalUsage, false, \ 752 "Reduce the use of OS signals in Java and/or the VM") \ 753 \ 754 develop(bool, LoadLineNumberTables, true, \ 755 "Tell whether the class file parser loads line number tables") \ 756 \ 757 develop(bool, LoadLocalVariableTables, true, \ 758 "Tell whether the class file parser loads local variable tables") \ 759 \ 760 develop(bool, LoadLocalVariableTypeTables, true, \ 761 "Tell whether the class file parser loads local variable type" \ 762 "tables") \ 763 \ 764 product(bool, AllowUserSignalHandlers, false, \ 765 "Application will install primary signal handlers for the JVM " \ 766 "(Unix only)") \ 767 \ 768 product(bool, UseSignalChaining, true, \ 769 "Use signal-chaining to invoke signal handlers installed " \ 770 "by the application (Unix only)") \ 771 \ 772 product(bool, RestoreMXCSROnJNICalls, false, \ 773 "Restore MXCSR when returning from JNI calls") \ 774 \ 775 product(bool, CheckJNICalls, false, \ 776 "Verify all arguments to JNI calls") \ 777 \ 778 product(bool, UseFastJNIAccessors, true, \ 779 "Use optimized versions of Get<Primitive>Field") \ 780 \ 781 product(intx, MaxJNILocalCapacity, 65536, \ 782 "Maximum allowable local JNI handle capacity to " \ 783 "EnsureLocalCapacity() and PushLocalFrame(), " \ 784 "where <= 0 is unlimited, default: 65536") \ 785 range(min_intx, max_intx) \ 786 \ 787 product(bool, EagerXrunInit, false, \ 788 "Eagerly initialize -Xrun libraries; allows startup profiling, " \ 789 "but not all -Xrun libraries may support the state of the VM " \ 790 "at this time") \ 791 \ 792 product(bool, PreserveAllAnnotations, false, \ 793 "Preserve RuntimeInvisibleAnnotations as well " \ 794 "as RuntimeVisibleAnnotations") \ 795 \ 796 develop(uintx, PreallocatedOutOfMemoryErrorCount, 4, \ 797 "Number of OutOfMemoryErrors preallocated with backtrace") \ 798 \ 799 product(bool, UseXMMForArrayCopy, false, \ 800 "Use SSE2 MOVQ instruction for Arraycopy") \ 801 \ 802 notproduct(bool, PrintFieldLayout, false, \ 803 "Print field layout for each class") \ 804 \ 805 /* Need to limit the extent of the padding to reasonable size. */\ 806 /* 8K is well beyond the reasonable HW cache line size, even with */\ 807 /* aggressive prefetching, while still leaving the room for segregating */\ 808 /* among the distinct pages. */\ 809 product(int, ContendedPaddingWidth, 128, \ 810 "How many bytes to pad the fields/classes marked @Contended with")\ 811 range(0, 8192) \ 812 constraint(ContendedPaddingWidthConstraintFunc,AfterErgo) \ 813 \ 814 product(bool, EnableContended, true, \ 815 "Enable @Contended annotation support") \ 816 \ 817 product(bool, RestrictContended, true, \ 818 "Restrict @Contended to trusted classes") \ 819 \ 820 product(int, DiagnoseSyncOnValueBasedClasses, 0, DIAGNOSTIC, \ 821 "Detect and take action upon identifying synchronization on " \ 822 "value based classes. Modes: " \ 823 "0: off; " \ 824 "1: exit with fatal error; " \ 825 "2: log message to stdout. Output file can be specified with " \ 826 " -Xlog:valuebasedclasses. If JFR is running it will " \ 827 " also generate JFR events.") \ 828 range(0, 2) \ 829 \ 830 product(bool, ExitOnOutOfMemoryError, false, \ 831 "JVM exits on the first occurrence of an out-of-memory error " \ 832 "thrown from JVM") \ 833 \ 834 product(bool, CrashOnOutOfMemoryError, false, \ 835 "JVM aborts, producing an error log and core/mini dump, on the " \ 836 "first occurrence of an out-of-memory error thrown from JVM") \ 837 \ 838 /* tracing */ \ 839 \ 840 develop(bool, StressRewriter, false, \ 841 "Stress linktime bytecode rewriting") \ 842 \ 843 product(ccstr, TraceJVMTI, nullptr, \ 844 "Trace flags for JVMTI functions and events") \ 845 \ 846 product(bool, StressLdcRewrite, false, DIAGNOSTIC, \ 847 "Force ldc -> ldc_w rewrite during RedefineClasses. " \ 848 "This option can change an EMCP method into an obsolete method " \ 849 "and can affect tests that expect specific methods to be EMCP. " \ 850 "This option should be used with caution.") \ 851 \ 852 product(bool, AllowRedefinitionToAddDeleteMethods, false, \ 853 "(Deprecated) Allow redefinition to add and delete private " \ 854 "static or final methods for compatibility with old releases") \ 855 \ 856 develop(bool, TraceBytecodes, false, \ 857 "Trace bytecode execution") \ 858 \ 859 develop(bool, TraceICs, false, \ 860 "Trace inline cache changes") \ 861 \ 862 notproduct(bool, TraceInvocationCounterOverflow, false, \ 863 "Trace method invocation counter overflow") \ 864 \ 865 develop(bool, TraceInlineCacheClearing, false, \ 866 "Trace clearing of inline caches in nmethods") \ 867 \ 868 develop(bool, VerifyDependencies, trueInDebug, \ 869 "Exercise and verify the compilation dependency mechanism") \ 870 \ 871 develop(bool, TraceNewOopMapGeneration, false, \ 872 "Trace OopMapGeneration") \ 873 \ 874 develop(bool, TraceNewOopMapGenerationDetailed, false, \ 875 "Trace OopMapGeneration: print detailed cell states") \ 876 \ 877 develop(bool, TimeOopMap, false, \ 878 "Time calls to GenerateOopMap::compute_map() in sum") \ 879 \ 880 develop(bool, TimeOopMap2, false, \ 881 "Time calls to GenerateOopMap::compute_map() individually") \ 882 \ 883 develop(bool, TraceOopMapRewrites, false, \ 884 "Trace rewriting of methods during oop map generation") \ 885 \ 886 develop(bool, TraceICBuffer, false, \ 887 "Trace usage of IC buffer") \ 888 \ 889 develop(bool, TraceCompiledIC, false, \ 890 "Trace changes of compiled IC") \ 891 \ 892 develop(bool, FLSVerifyDictionary, false, \ 893 "Do lots of (expensive) FLS dictionary verification") \ 894 \ 895 product(uintx, ProcessDistributionStride, 4, \ 896 "Stride through processors when distributing processes") \ 897 range(0, max_juint) \ 898 \ 899 develop(bool, TraceFinalizerRegistration, false, \ 900 "Trace registration of final references") \ 901 \ 902 product(bool, IgnoreEmptyClassPaths, false, \ 903 "Ignore empty path elements in -classpath") \ 904 \ 905 product(bool, PrintHeapAtSIGBREAK, true, \ 906 "Print heap layout in response to SIGBREAK") \ 907 \ 908 product(bool, PrintClassHistogram, false, MANAGEABLE, \ 909 "Print a histogram of class instances") \ 910 \ 911 product(double, ObjectCountCutOffPercent, 0.5, EXPERIMENTAL, \ 912 "The percentage of the used heap that the instances of a class " \ 913 "must occupy for the class to generate a trace event") \ 914 range(0.0, 100.0) \ 915 \ 916 /* JVMTI heap profiling */ \ 917 \ 918 product(bool, VerifyBeforeIteration, false, DIAGNOSTIC, \ 919 "Verify memory system before JVMTI iteration") \ 920 \ 921 /* compiler */ \ 922 \ 923 /* notice: the max range value here is max_jint, not max_intx */ \ 924 /* because of overflow issue */ \ 925 product(intx, CICompilerCount, CI_COMPILER_COUNT, \ 926 "Number of compiler threads to run") \ 927 range(0, max_jint) \ 928 constraint(CICompilerCountConstraintFunc, AfterErgo) \ 929 \ 930 product(bool, UseDynamicNumberOfCompilerThreads, true, \ 931 "Dynamically choose the number of parallel compiler threads") \ 932 \ 933 product(bool, ReduceNumberOfCompilerThreads, true, DIAGNOSTIC, \ 934 "Reduce the number of parallel compiler threads when they " \ 935 "are not used") \ 936 \ 937 product(bool, TraceCompilerThreads, false, DIAGNOSTIC, \ 938 "Trace creation and removal of compiler threads") \ 939 \ 940 product(ccstr, LogClassLoadingCauseFor, nullptr, \ 941 "Apply -Xlog:class+load+cause* to classes whose fully " \ 942 "qualified name contains this string (\"*\" matches " \ 943 "any class).") \ 944 \ 945 develop(bool, InjectCompilerCreationFailure, false, \ 946 "Inject thread creation failures for " \ 947 "UseDynamicNumberOfCompilerThreads") \ 948 \ 949 develop(bool, GenerateSynchronizationCode, true, \ 950 "generate locking/unlocking code for synchronized methods and " \ 951 "monitors") \ 952 \ 953 product_pd(bool, ImplicitNullChecks, DIAGNOSTIC, \ 954 "Generate code for implicit null checks") \ 955 \ 956 product_pd(bool, TrapBasedNullChecks, \ 957 "Generate code for null checks that uses a cmp and trap " \ 958 "instruction raising SIGTRAP. This is only used if an access to" \ 959 "null (+offset) will not raise a SIGSEGV, i.e.," \ 960 "ImplicitNullChecks don't work (PPC64).") \ 961 \ 962 product(bool, EnableThreadSMRStatistics, trueInDebug, DIAGNOSTIC, \ 963 "Enable Thread SMR Statistics") \ 964 \ 965 product(bool, UseNotificationThread, true, \ 966 "Use Notification Thread") \ 967 \ 968 product(bool, Inline, true, \ 969 "Enable inlining") \ 970 \ 971 product(bool, ClipInlining, true, \ 972 "Clip inlining if aggregate method exceeds DesiredMethodLimit") \ 973 \ 974 develop(bool, UseCHA, true, \ 975 "Enable CHA") \ 976 \ 977 product(bool, UseVtableBasedCHA, true, DIAGNOSTIC, \ 978 "Use vtable information during CHA") \ 979 \ 980 product(bool, UseTypeProfile, true, \ 981 "Check interpreter profile for historically monomorphic calls") \ 982 \ 983 product(bool, PrintInlining, false, DIAGNOSTIC, \ 984 "Print inlining optimizations") \ 985 \ 986 product(bool, UsePopCountInstruction, false, \ 987 "Use population count instruction") \ 988 \ 989 develop(bool, TraceMethodReplacement, false, \ 990 "Print when methods are replaced do to recompilation") \ 991 \ 992 product(bool, PrintMethodFlushingStatistics, false, DIAGNOSTIC, \ 993 "print statistics about method flushing") \ 994 \ 995 product(intx, MinPassesBeforeFlush, 10, DIAGNOSTIC, \ 996 "Minimum number of sweeper passes before an nmethod " \ 997 "can be flushed") \ 998 range(0, max_intx) \ 999 \ 1000 develop(bool, StressCodeBuffers, false, \ 1001 "Exercise code buffer expansion and other rare state changes") \ 1002 \ 1003 product(bool, DebugNonSafepoints, trueInDebug, DIAGNOSTIC, \ 1004 "Generate extra debugging information for non-safepoints in " \ 1005 "nmethods") \ 1006 \ 1007 product(bool, PrintVMOptions, false, \ 1008 "Print flags that appeared on the command line") \ 1009 \ 1010 product(bool, IgnoreUnrecognizedVMOptions, false, \ 1011 "Ignore unrecognized VM options") \ 1012 \ 1013 product(bool, PrintCommandLineFlags, false, \ 1014 "Print flags specified on command line or set by ergonomics") \ 1015 \ 1016 product(bool, PrintFlagsInitial, false, \ 1017 "Print all VM flags before argument processing and exit VM") \ 1018 \ 1019 product(bool, PrintFlagsFinal, false, \ 1020 "Print all VM flags after argument and ergonomic processing") \ 1021 \ 1022 notproduct(bool, PrintFlagsWithComments, false, \ 1023 "Print all VM flags with default values and descriptions and " \ 1024 "exit") \ 1025 \ 1026 product(bool, PrintFlagsRanges, false, \ 1027 "Print VM flags and their ranges") \ 1028 \ 1029 product(bool, SerializeVMOutput, true, DIAGNOSTIC, \ 1030 "Use a mutex to serialize output to tty and LogFile") \ 1031 \ 1032 product(bool, DisplayVMOutput, true, DIAGNOSTIC, \ 1033 "Display all VM output on the tty, independently of LogVMOutput") \ 1034 \ 1035 product(bool, LogVMOutput, false, DIAGNOSTIC, \ 1036 "Save VM output to LogFile") \ 1037 \ 1038 product(ccstr, LogFile, nullptr, DIAGNOSTIC, \ 1039 "If LogVMOutput or LogCompilation is on, save VM output to " \ 1040 "this file [default: ./hotspot_pid%p.log] (%p replaced with pid)")\ 1041 \ 1042 product(ccstr, ErrorFile, nullptr, \ 1043 "If an error occurs, save the error data to this file " \ 1044 "[default: ./hs_err_pid%p.log] (%p replaced with pid)") \ 1045 \ 1046 product(bool, ExtensiveErrorReports, \ 1047 PRODUCT_ONLY(false) NOT_PRODUCT(true), \ 1048 "Error reports are more extensive.") \ 1049 \ 1050 product(bool, DisplayVMOutputToStderr, false, \ 1051 "If DisplayVMOutput is true, display all VM output to stderr") \ 1052 \ 1053 product(bool, DisplayVMOutputToStdout, false, \ 1054 "If DisplayVMOutput is true, display all VM output to stdout") \ 1055 \ 1056 product(bool, ErrorFileToStderr, false, \ 1057 "If true, error data is printed to stderr instead of a file") \ 1058 \ 1059 product(bool, ErrorFileToStdout, false, \ 1060 "If true, error data is printed to stdout instead of a file") \ 1061 \ 1062 product(bool, UseHeavyMonitors, false, DIAGNOSTIC, \ 1063 "(Deprecated) Use heavyweight instead of lightweight Java " \ 1064 "monitors") \ 1065 \ 1066 develop(bool, VerifyHeavyMonitors, false, \ 1067 "Checks that no stack locking happens when using " \ 1068 "+UseHeavyMonitors") \ 1069 \ 1070 product(bool, PrintStringTableStatistics, false, \ 1071 "print statistics about the StringTable and SymbolTable") \ 1072 \ 1073 product(bool, VerifyStringTableAtExit, false, DIAGNOSTIC, \ 1074 "verify StringTable contents at exit") \ 1075 \ 1076 notproduct(bool, PrintSymbolTableSizeHistogram, false, \ 1077 "print histogram of the symbol table") \ 1078 \ 1079 product(ccstr, AbortVMOnException, nullptr, DIAGNOSTIC, \ 1080 "Call fatal if this exception is thrown. Example: " \ 1081 "java -XX:AbortVMOnException=java.lang.NullPointerException Foo") \ 1082 \ 1083 product(ccstr, AbortVMOnExceptionMessage, nullptr, DIAGNOSTIC, \ 1084 "Call fatal if the exception pointed by AbortVMOnException " \ 1085 "has this message") \ 1086 \ 1087 develop(bool, DebugVtables, false, \ 1088 "add debugging code to vtable dispatch") \ 1089 \ 1090 product(bool, RangeCheckElimination, true, \ 1091 "Eliminate range checks") \ 1092 \ 1093 develop_pd(bool, UncommonNullCast, \ 1094 "track occurrences of null in casts; adjust compiler tactics") \ 1095 \ 1096 develop(bool, TypeProfileCasts, true, \ 1097 "treat casts like calls for purposes of type profiling") \ 1098 \ 1099 develop(bool, TraceLivenessGen, false, \ 1100 "Trace the generation of liveness analysis information") \ 1101 \ 1102 notproduct(bool, TraceLivenessQuery, false, \ 1103 "Trace queries of liveness analysis information") \ 1104 \ 1105 notproduct(bool, CollectIndexSetStatistics, false, \ 1106 "Collect information about IndexSets") \ 1107 \ 1108 develop(int, FastAllocateSizeLimit, 128*K, \ 1109 /* Note: This value is zero mod 1<<13 for a cheap sparc set. */ \ 1110 "Inline allocations larger than this in doublewords must go slow")\ 1111 \ 1112 product_pd(bool, CompactStrings, \ 1113 "Enable Strings to use single byte chars in backing store") \ 1114 \ 1115 product_pd(uint, TypeProfileLevel, \ 1116 "=XYZ, with Z: Type profiling of arguments at call; " \ 1117 "Y: Type profiling of return value at call; " \ 1118 "X: Type profiling of parameters to methods; " \ 1119 "X, Y and Z in 0=off ; 1=jsr292 only; 2=all methods") \ 1120 constraint(TypeProfileLevelConstraintFunc, AfterErgo) \ 1121 \ 1122 product(int, TypeProfileArgsLimit, 2, \ 1123 "max number of call arguments to consider for type profiling") \ 1124 range(0, 16) \ 1125 \ 1126 product(int, TypeProfileParmsLimit, 2, \ 1127 "max number of incoming parameters to consider for type profiling"\ 1128 ", -1 for all") \ 1129 range(-1, 64) \ 1130 \ 1131 /* statistics */ \ 1132 develop(bool, CountCompiledCalls, false, \ 1133 "Count method invocations") \ 1134 \ 1135 notproduct(bool, ICMissHistogram, false, \ 1136 "Produce histogram of IC misses") \ 1137 \ 1138 /* interpreter */ \ 1139 product_pd(bool, RewriteBytecodes, \ 1140 "Allow rewriting of bytecodes (bytecodes are not immutable)") \ 1141 \ 1142 product_pd(bool, RewriteFrequentPairs, \ 1143 "Rewrite frequently used bytecode pairs into a single bytecode") \ 1144 \ 1145 product(bool, PrintInterpreter, false, DIAGNOSTIC, \ 1146 "Print the generated interpreter code") \ 1147 \ 1148 product(bool, UseInterpreter, true, \ 1149 "Use interpreter for non-compiled methods") \ 1150 \ 1151 develop(bool, UseFastSignatureHandlers, true, \ 1152 "Use fast signature handlers for native calls") \ 1153 \ 1154 product(bool, UseLoopCounter, true, \ 1155 "Increment invocation counter on backward branch") \ 1156 \ 1157 product_pd(bool, UseOnStackReplacement, \ 1158 "Use on stack replacement, calls runtime if invoc. counter " \ 1159 "overflows in loop") \ 1160 \ 1161 notproduct(bool, TraceOnStackReplacement, false, \ 1162 "Trace on stack replacement") \ 1163 \ 1164 product_pd(bool, PreferInterpreterNativeStubs, \ 1165 "Use always interpreter stubs for native methods invoked via " \ 1166 "interpreter") \ 1167 \ 1168 develop(bool, CountBytecodes, false, \ 1169 "Count number of bytecodes executed") \ 1170 \ 1171 develop(bool, PrintBytecodeHistogram, false, \ 1172 "Print histogram of the executed bytecodes") \ 1173 \ 1174 develop(bool, PrintBytecodePairHistogram, false, \ 1175 "Print histogram of the executed bytecode pairs") \ 1176 \ 1177 product(bool, PrintSignatureHandlers, false, DIAGNOSTIC, \ 1178 "Print code generated for native method signature handlers") \ 1179 \ 1180 develop(bool, VerifyOops, false, \ 1181 "Do plausibility checks for oops") \ 1182 \ 1183 develop(bool, CheckUnhandledOops, false, \ 1184 "Check for unhandled oops in VM code") \ 1185 \ 1186 develop(bool, VerifyJNIFields, trueInDebug, \ 1187 "Verify jfieldIDs for instance fields") \ 1188 \ 1189 develop(bool, VerifyFPU, false, \ 1190 "Verify FPU state (check for NaN's, etc.)") \ 1191 \ 1192 develop(bool, VerifyActivationFrameSize, false, \ 1193 "Verify that activation frame didn't become smaller than its " \ 1194 "minimal size") \ 1195 \ 1196 develop(bool, TraceFrequencyInlining, false, \ 1197 "Trace frequency based inlining") \ 1198 \ 1199 develop_pd(bool, InlineIntrinsics, \ 1200 "Use intrinsics in Interpreter that can be statically resolved") \ 1201 \ 1202 product_pd(bool, ProfileInterpreter, \ 1203 "Profile at the bytecode level during interpretation") \ 1204 \ 1205 develop_pd(bool, ProfileTraps, \ 1206 "Profile deoptimization traps at the bytecode level") \ 1207 \ 1208 product(intx, ProfileMaturityPercentage, 20, \ 1209 "number of method invocations/branches (expressed as % of " \ 1210 "CompileThreshold) before using the method's profile") \ 1211 range(0, 100) \ 1212 \ 1213 product(bool, PrintMethodData, false, DIAGNOSTIC, \ 1214 "Print the results of +ProfileInterpreter at end of run") \ 1215 \ 1216 develop(bool, VerifyDataPointer, trueInDebug, \ 1217 "Verify the method data pointer during interpreter profiling") \ 1218 \ 1219 notproduct(bool, CrashGCForDumpingJavaThread, false, \ 1220 "Manually make GC thread crash then dump java stack trace; " \ 1221 "Test only") \ 1222 \ 1223 /* compilation */ \ 1224 product(bool, UseCompiler, true, \ 1225 "Use Just-In-Time compilation") \ 1226 \ 1227 product(bool, UseCounterDecay, true, \ 1228 "Adjust recompilation counters") \ 1229 \ 1230 develop(intx, CounterHalfLifeTime, 30, \ 1231 "Half-life time of invocation counters (in seconds)") \ 1232 \ 1233 develop(intx, CounterDecayMinIntervalLength, 500, \ 1234 "The minimum interval (in milliseconds) between invocation of " \ 1235 "CounterDecay") \ 1236 \ 1237 product(bool, AlwaysCompileLoopMethods, false, \ 1238 "When using recompilation, never interpret methods " \ 1239 "containing loops") \ 1240 \ 1241 product(int, AllocatePrefetchStyle, 1, \ 1242 "0 = no prefetch, " \ 1243 "1 = generate prefetch instructions for each allocation, " \ 1244 "2 = use TLAB watermark to gate allocation prefetch, " \ 1245 "3 = generate one prefetch instruction per cache line") \ 1246 range(0, 3) \ 1247 \ 1248 product(int, AllocatePrefetchDistance, -1, \ 1249 "Distance to prefetch ahead of allocation pointer. " \ 1250 "-1: use system-specific value (automatically determined") \ 1251 range(-1, 512) \ 1252 \ 1253 product(int, AllocatePrefetchLines, 3, \ 1254 "Number of lines to prefetch ahead of array allocation pointer") \ 1255 range(1, 64) \ 1256 \ 1257 product(int, AllocateInstancePrefetchLines, 1, \ 1258 "Number of lines to prefetch ahead of instance allocation " \ 1259 "pointer") \ 1260 range(1, 64) \ 1261 \ 1262 product(int, AllocatePrefetchStepSize, 16, \ 1263 "Step size in bytes of sequential prefetch instructions") \ 1264 range(1, 512) \ 1265 constraint(AllocatePrefetchStepSizeConstraintFunc,AfterMemoryInit)\ 1266 \ 1267 product(intx, AllocatePrefetchInstr, 0, \ 1268 "Select instruction to prefetch ahead of allocation pointer") \ 1269 constraint(AllocatePrefetchInstrConstraintFunc, AfterMemoryInit) \ 1270 \ 1271 /* deoptimization */ \ 1272 product(bool, TraceDeoptimization, false, DIAGNOSTIC, \ 1273 "Trace deoptimization") \ 1274 \ 1275 develop(bool, PrintDeoptimizationDetails, false, \ 1276 "Print more information about deoptimization") \ 1277 \ 1278 develop(bool, DebugDeoptimization, false, \ 1279 "Tracing various information while debugging deoptimization") \ 1280 \ 1281 product(double, SelfDestructTimer, 0.0, \ 1282 "Will cause VM to terminate after a given time " \ 1283 "(in fractional minutes) " \ 1284 "(0.0 means off)") \ 1285 range(0.0, (double)max_intx) \ 1286 \ 1287 product(int, MaxJavaStackTraceDepth, 1024, \ 1288 "The maximum number of lines in the stack trace for Java " \ 1289 "exceptions (0 means all)") \ 1290 range(0, max_jint/2) \ 1291 \ 1292 /* notice: the max range value here is max_jint, not max_intx */ \ 1293 /* because of overflow issue */ \ 1294 product(intx, GuaranteedSafepointInterval, 1000, DIAGNOSTIC, \ 1295 "Guarantee a safepoint (at least) every so many milliseconds " \ 1296 "(0 means none)") \ 1297 range(0, max_jint) \ 1298 \ 1299 product(double, SafepointTimeoutDelay, 10000, \ 1300 "Delay in milliseconds for option SafepointTimeout; " \ 1301 "supports sub-millisecond resolution with fractional values.") \ 1302 range(0, max_jlongDouble LP64_ONLY(/MICROUNITS)) \ 1303 \ 1304 product(bool, UseSystemMemoryBarrier, false, \ 1305 "Try to enable system memory barrier if supported by OS") \ 1306 \ 1307 product(intx, NmethodSweepActivity, 4, \ 1308 "Removes cold nmethods from code cache if > 0. Higher values " \ 1309 "result in more aggressive sweeping") \ 1310 range(0, 2000) \ 1311 \ 1312 develop(intx, MallocCatchPtr, -1, \ 1313 "Hit breakpoint when mallocing/freeing this pointer") \ 1314 \ 1315 develop(int, StackPrintLimit, 100, \ 1316 "number of stack frames to print in VM-level stack dump") \ 1317 \ 1318 product(int, ErrorLogPrintCodeLimit, 3, DIAGNOSTIC, \ 1319 "max number of compiled code units to print in error log") \ 1320 range(0, VMError::max_error_log_print_code) \ 1321 \ 1322 notproduct(intx, MaxElementPrintSize, 256, \ 1323 "maximum number of elements to print") \ 1324 \ 1325 notproduct(intx, MaxSubklassPrintSize, 4, \ 1326 "maximum number of subklasses to print when printing klass") \ 1327 \ 1328 develop(intx, MaxForceInlineLevel, 100, \ 1329 "maximum number of nested calls that are forced for inlining " \ 1330 "(using CompileCommand or marked w/ @ForceInline)") \ 1331 range(0, max_jint) \ 1332 \ 1333 develop(intx, MethodHistogramCutoff, 100, \ 1334 "The cutoff value for method invocation histogram (+CountCalls)") \ 1335 \ 1336 develop(intx, DontYieldALotInterval, 10, \ 1337 "Interval between which yields will be dropped (milliseconds)") \ 1338 \ 1339 notproduct(intx, DeoptimizeALotInterval, 5, \ 1340 "Number of exits until DeoptimizeALot kicks in") \ 1341 \ 1342 notproduct(intx, ZombieALotInterval, 5, \ 1343 "Number of exits until ZombieALot kicks in") \ 1344 \ 1345 product(ccstr, MallocLimit, nullptr, DIAGNOSTIC, \ 1346 "Limit malloc allocation size from VM. Reaching a limit will " \ 1347 "trigger an action (see flag). This feature requires " \ 1348 "NativeMemoryTracking=summary or NativeMemoryTracking=detail." \ 1349 "Usage:" \ 1350 "\"-XX:MallocLimit=<size>[:<flag>]\" sets a total limit." \ 1351 "\"-XX:MallocLimit=<category>:<size>[:<flag>][,<category>:<size>[:<flag>] ...]\"" \ 1352 "sets one or more category-specific limits." \ 1353 "<flag> defines the action upon reaching the limit:" \ 1354 "\"fatal\": end VM with a fatal error at the allocation site" \ 1355 "\"oom\" : will mimic a native OOM" \ 1356 "If <flag> is omitted, \"fatal\" is the default." \ 1357 "Examples:\n" \ 1358 "-XX:MallocLimit=2g" \ 1359 "-XX:MallocLimit=2g:oom" \ 1360 "-XX:MallocLimit=compiler:200m:oom,code:100m") \ 1361 \ 1362 product(intx, TypeProfileWidth, 2, \ 1363 "Number of receiver types to record in call/cast profile") \ 1364 range(0, 8) \ 1365 \ 1366 develop(intx, BciProfileWidth, 2, \ 1367 "Number of return bci's to record in ret profile") \ 1368 \ 1369 product(intx, PerMethodRecompilationCutoff, 400, \ 1370 "After recompiling N times, stay in the interpreter (-1=>'Inf')") \ 1371 range(-1, max_intx) \ 1372 \ 1373 product(intx, PerBytecodeRecompilationCutoff, 200, \ 1374 "Per-BCI limit on repeated recompilation (-1=>'Inf')") \ 1375 range(-1, max_intx) \ 1376 \ 1377 product(intx, PerMethodTrapLimit, 100, \ 1378 "Limit on traps (of one kind) in a method (includes inlines)") \ 1379 range(0, max_jint) \ 1380 \ 1381 product(intx, PerMethodSpecTrapLimit, 5000, EXPERIMENTAL, \ 1382 "Limit on speculative traps (of one kind) in a method " \ 1383 "(includes inlines)") \ 1384 range(0, max_jint) \ 1385 \ 1386 product(intx, PerBytecodeTrapLimit, 4, \ 1387 "Limit on traps (of one kind) at a particular BCI") \ 1388 range(0, max_jint) \ 1389 \ 1390 product(int, SpecTrapLimitExtraEntries, 3, EXPERIMENTAL, \ 1391 "Extra method data trap entries for speculation") \ 1392 \ 1393 product(double, InlineFrequencyRatio, 0.25, DIAGNOSTIC, \ 1394 "Ratio of call site execution to caller method invocation") \ 1395 \ 1396 product(double, MinInlineFrequencyRatio, 0.0085, DIAGNOSTIC, \ 1397 "Minimum ratio of call site execution to caller method" \ 1398 "invocation to be considered for inlining") \ 1399 \ 1400 develop(intx, InlineThrowCount, 50, \ 1401 "Force inlining of interpreted methods that throw this often") \ 1402 range(0, max_jint) \ 1403 \ 1404 develop(intx, InlineThrowMaxSize, 200, \ 1405 "Force inlining of throwing methods smaller than this") \ 1406 range(0, max_jint) \ 1407 \ 1408 product(size_t, MetaspaceSize, NOT_LP64(16 * M) LP64_ONLY(21 * M), \ 1409 "Initial threshold (in bytes) at which a garbage collection " \ 1410 "is done to reduce Metaspace usage") \ 1411 constraint(MetaspaceSizeConstraintFunc,AfterErgo) \ 1412 \ 1413 product(size_t, MaxMetaspaceSize, max_uintx, \ 1414 "Maximum size of Metaspaces (in bytes)") \ 1415 constraint(MaxMetaspaceSizeConstraintFunc,AfterErgo) \ 1416 \ 1417 product(size_t, CompressedClassSpaceSize, 1*G, \ 1418 "Maximum size of class area in Metaspace when compressed " \ 1419 "class pointers are used") \ 1420 range(1*M, 3*G) \ 1421 \ 1422 develop(size_t, CompressedClassSpaceBaseAddress, 0, \ 1423 "Force the class space to be allocated at this address or " \ 1424 "fails VM initialization (requires -Xshare=off.") \ 1425 \ 1426 product(bool, PrintMetaspaceStatisticsAtExit, false, DIAGNOSTIC, \ 1427 "Print metaspace statistics upon VM exit.") \ 1428 \ 1429 develop(bool, MetaspaceGuardAllocations, false, \ 1430 "Metapace allocations are guarded.") \ 1431 \ 1432 product(uintx, MinHeapFreeRatio, 40, MANAGEABLE, \ 1433 "The minimum percentage of heap free after GC to avoid expansion."\ 1434 " For most GCs this applies to the old generation. In G1 and" \ 1435 " ParallelGC it applies to the whole heap.") \ 1436 range(0, 100) \ 1437 constraint(MinHeapFreeRatioConstraintFunc,AfterErgo) \ 1438 \ 1439 product(uintx, MaxHeapFreeRatio, 70, MANAGEABLE, \ 1440 "The maximum percentage of heap free after GC to avoid shrinking."\ 1441 " For most GCs this applies to the old generation. In G1 and" \ 1442 " ParallelGC it applies to the whole heap.") \ 1443 range(0, 100) \ 1444 constraint(MaxHeapFreeRatioConstraintFunc,AfterErgo) \ 1445 \ 1446 product(bool, ShrinkHeapInSteps, true, \ 1447 "When disabled, informs the GC to shrink the java heap directly" \ 1448 " to the target size at the next full GC rather than requiring" \ 1449 " smaller steps during multiple full GCs.") \ 1450 \ 1451 product(intx, SoftRefLRUPolicyMSPerMB, 1000, \ 1452 "Number of milliseconds per MB of free space in the heap") \ 1453 range(0, max_intx) \ 1454 constraint(SoftRefLRUPolicyMSPerMBConstraintFunc,AfterMemoryInit) \ 1455 \ 1456 product(size_t, MinHeapDeltaBytes, ScaleForWordSize(128*K), \ 1457 "The minimum change in heap space due to GC (in bytes)") \ 1458 range(0, max_uintx) \ 1459 \ 1460 product(size_t, MinMetaspaceExpansion, ScaleForWordSize(256*K), \ 1461 "The minimum expansion of Metaspace (in bytes)") \ 1462 range(0, max_uintx) \ 1463 \ 1464 product(uintx, MaxMetaspaceFreeRatio, 70, \ 1465 "The maximum percentage of Metaspace free after GC to avoid " \ 1466 "shrinking") \ 1467 range(0, 100) \ 1468 constraint(MaxMetaspaceFreeRatioConstraintFunc,AfterErgo) \ 1469 \ 1470 product(uintx, MinMetaspaceFreeRatio, 40, \ 1471 "The minimum percentage of Metaspace free after GC to avoid " \ 1472 "expansion") \ 1473 range(0, 99) \ 1474 constraint(MinMetaspaceFreeRatioConstraintFunc,AfterErgo) \ 1475 \ 1476 product(size_t, MaxMetaspaceExpansion, ScaleForWordSize(4*M), \ 1477 "The maximum expansion of Metaspace without full GC (in bytes)") \ 1478 range(0, max_uintx) \ 1479 \ 1480 /* stack parameters */ \ 1481 product_pd(intx, StackYellowPages, \ 1482 "Number of yellow zone (recoverable overflows) pages of size " \ 1483 "4KB. If pages are bigger yellow zone is aligned up.") \ 1484 range(MIN_STACK_YELLOW_PAGES, (DEFAULT_STACK_YELLOW_PAGES+5)) \ 1485 \ 1486 product_pd(intx, StackRedPages, \ 1487 "Number of red zone (unrecoverable overflows) pages of size " \ 1488 "4KB. If pages are bigger red zone is aligned up.") \ 1489 range(MIN_STACK_RED_PAGES, (DEFAULT_STACK_RED_PAGES+2)) \ 1490 \ 1491 product_pd(intx, StackReservedPages, \ 1492 "Number of reserved zone (reserved to annotated methods) pages" \ 1493 " of size 4KB. If pages are bigger reserved zone is aligned up.") \ 1494 range(MIN_STACK_RESERVED_PAGES, (DEFAULT_STACK_RESERVED_PAGES+10))\ 1495 \ 1496 product(bool, RestrictReservedStack, true, \ 1497 "Restrict @ReservedStackAccess to trusted classes") \ 1498 \ 1499 /* greater stack shadow pages can't generate instruction to bang stack */ \ 1500 product_pd(intx, StackShadowPages, \ 1501 "Number of shadow zone (for overflow checking) pages of size " \ 1502 "4KB. If pages are bigger shadow zone is aligned up. " \ 1503 "This should exceed the depth of the VM and native call stack.") \ 1504 range(MIN_STACK_SHADOW_PAGES, (DEFAULT_STACK_SHADOW_PAGES+30)) \ 1505 \ 1506 product_pd(intx, ThreadStackSize, \ 1507 "Thread Stack Size (in Kbytes)") \ 1508 range(0, 1 * M) \ 1509 \ 1510 product_pd(intx, VMThreadStackSize, \ 1511 "Non-Java Thread Stack Size (in Kbytes)") \ 1512 range(0, max_intx/(1 * K)) \ 1513 \ 1514 product_pd(intx, CompilerThreadStackSize, \ 1515 "Compiler Thread Stack Size (in Kbytes)") \ 1516 range(0, max_intx/(1 * K)) \ 1517 \ 1518 develop_pd(size_t, JVMInvokeMethodSlack, \ 1519 "Stack space (bytes) required for JVM_InvokeMethod to complete") \ 1520 \ 1521 /* code cache parameters */ \ 1522 product_pd(uintx, CodeCacheSegmentSize, EXPERIMENTAL, \ 1523 "Code cache segment size (in bytes) - smallest unit of " \ 1524 "allocation") \ 1525 range(1, 1024) \ 1526 constraint(CodeCacheSegmentSizeConstraintFunc, AfterErgo) \ 1527 \ 1528 product_pd(intx, CodeEntryAlignment, EXPERIMENTAL, \ 1529 "Code entry alignment for generated code (in bytes)") \ 1530 constraint(CodeEntryAlignmentConstraintFunc, AfterErgo) \ 1531 \ 1532 product_pd(intx, OptoLoopAlignment, \ 1533 "Align inner loops to zero relative to this modulus") \ 1534 range(1, 128) \ 1535 constraint(OptoLoopAlignmentConstraintFunc, AfterErgo) \ 1536 \ 1537 product_pd(uintx, InitialCodeCacheSize, \ 1538 "Initial code cache size (in bytes)") \ 1539 constraint(VMPageSizeConstraintFunc, AtParse) \ 1540 \ 1541 develop_pd(uintx, CodeCacheMinimumUseSpace, \ 1542 "Minimum code cache size (in bytes) required to start VM.") \ 1543 range(0, max_uintx) \ 1544 \ 1545 product(bool, SegmentedCodeCache, false, \ 1546 "Use a segmented code cache") \ 1547 \ 1548 product_pd(uintx, ReservedCodeCacheSize, \ 1549 "Reserved code cache size (in bytes) - maximum code cache size") \ 1550 constraint(VMPageSizeConstraintFunc, AtParse) \ 1551 \ 1552 product_pd(uintx, NonProfiledCodeHeapSize, \ 1553 "Size of code heap with non-profiled methods (in bytes)") \ 1554 range(0, max_uintx) \ 1555 \ 1556 product_pd(uintx, ProfiledCodeHeapSize, \ 1557 "Size of code heap with profiled methods (in bytes)") \ 1558 range(0, max_uintx) \ 1559 \ 1560 product_pd(uintx, NonNMethodCodeHeapSize, \ 1561 "Size of code heap with non-nmethods (in bytes)") \ 1562 constraint(VMPageSizeConstraintFunc, AtParse) \ 1563 \ 1564 product_pd(uintx, CodeCacheExpansionSize, \ 1565 "Code cache expansion size (in bytes)") \ 1566 range(32*K, max_uintx) \ 1567 \ 1568 product_pd(uintx, CodeCacheMinBlockLength, DIAGNOSTIC, \ 1569 "Minimum number of segments in a code cache block") \ 1570 range(1, 100) \ 1571 \ 1572 notproduct(bool, ExitOnFullCodeCache, false, \ 1573 "Exit the VM if we fill the code cache") \ 1574 \ 1575 product(bool, UseCodeCacheFlushing, true, \ 1576 "Remove cold/old nmethods from the code cache") \ 1577 \ 1578 product(double, SweeperThreshold, 15.0, \ 1579 "Threshold when a code cache unloading GC is invoked." \ 1580 "Value is percentage of ReservedCodeCacheSize.") \ 1581 range(0.0, 100.0) \ 1582 \ 1583 product(uintx, StartAggressiveSweepingAt, 10, \ 1584 "Start aggressive sweeping if X[%] of the code cache is free." \ 1585 "Segmented code cache: X[%] of the non-profiled heap." \ 1586 "Non-segmented code cache: X[%] of the total code cache") \ 1587 range(0, 100) \ 1588 \ 1589 /* interpreter debugging */ \ 1590 develop(intx, BinarySwitchThreshold, 5, \ 1591 "Minimal number of lookupswitch entries for rewriting to binary " \ 1592 "switch") \ 1593 \ 1594 develop(intx, StopInterpreterAt, 0, \ 1595 "Stop interpreter execution at specified bytecode number") \ 1596 \ 1597 develop(intx, TraceBytecodesAt, 0, \ 1598 "Trace bytecodes starting with specified bytecode number") \ 1599 \ 1600 develop(intx, TraceBytecodesStopAt, 0, \ 1601 "Stop bytecode tracing at the specified bytecode number") \ 1602 \ 1603 /* Priorities */ \ 1604 product_pd(bool, UseThreadPriorities, "Use native thread priorities") \ 1605 \ 1606 product(int, ThreadPriorityPolicy, 0, \ 1607 "0 : Normal. "\ 1608 " VM chooses priorities that are appropriate for normal "\ 1609 " applications. "\ 1610 " On Windows applications are allowed to use higher native "\ 1611 " priorities. However, with ThreadPriorityPolicy=0, VM will "\ 1612 " not use the highest possible native priority, "\ 1613 " THREAD_PRIORITY_TIME_CRITICAL, as it may interfere with "\ 1614 " system threads. On Linux thread priorities are ignored "\ 1615 " because the OS does not support static priority in "\ 1616 " SCHED_OTHER scheduling class which is the only choice for "\ 1617 " non-root, non-realtime applications. "\ 1618 "1 : Aggressive. "\ 1619 " Java thread priorities map over to the entire range of "\ 1620 " native thread priorities. Higher Java thread priorities map "\ 1621 " to higher native thread priorities. This policy should be "\ 1622 " used with care, as sometimes it can cause performance "\ 1623 " degradation in the application and/or the entire system. On "\ 1624 " Linux/BSD/macOS this policy requires root privilege or an "\ 1625 " extended capability.") \ 1626 range(0, 1) \ 1627 \ 1628 product(bool, ThreadPriorityVerbose, false, \ 1629 "Print priority changes") \ 1630 \ 1631 product(int, CompilerThreadPriority, -1, \ 1632 "The native priority at which compiler threads should run " \ 1633 "(-1 means no change)") \ 1634 range(min_jint, max_jint) \ 1635 \ 1636 product(int, VMThreadPriority, -1, \ 1637 "The native priority at which the VM thread should run " \ 1638 "(-1 means no change)") \ 1639 range(-1, 127) \ 1640 \ 1641 product(int, JavaPriority1_To_OSPriority, -1, \ 1642 "Map Java priorities to OS priorities") \ 1643 range(-1, 127) \ 1644 \ 1645 product(int, JavaPriority2_To_OSPriority, -1, \ 1646 "Map Java priorities to OS priorities") \ 1647 range(-1, 127) \ 1648 \ 1649 product(int, JavaPriority3_To_OSPriority, -1, \ 1650 "Map Java priorities to OS priorities") \ 1651 range(-1, 127) \ 1652 \ 1653 product(int, JavaPriority4_To_OSPriority, -1, \ 1654 "Map Java priorities to OS priorities") \ 1655 range(-1, 127) \ 1656 \ 1657 product(int, JavaPriority5_To_OSPriority, -1, \ 1658 "Map Java priorities to OS priorities") \ 1659 range(-1, 127) \ 1660 \ 1661 product(int, JavaPriority6_To_OSPriority, -1, \ 1662 "Map Java priorities to OS priorities") \ 1663 range(-1, 127) \ 1664 \ 1665 product(int, JavaPriority7_To_OSPriority, -1, \ 1666 "Map Java priorities to OS priorities") \ 1667 range(-1, 127) \ 1668 \ 1669 product(int, JavaPriority8_To_OSPriority, -1, \ 1670 "Map Java priorities to OS priorities") \ 1671 range(-1, 127) \ 1672 \ 1673 product(int, JavaPriority9_To_OSPriority, -1, \ 1674 "Map Java priorities to OS priorities") \ 1675 range(-1, 127) \ 1676 \ 1677 product(int, JavaPriority10_To_OSPriority,-1, \ 1678 "Map Java priorities to OS priorities") \ 1679 range(-1, 127) \ 1680 \ 1681 product(bool, UseCriticalJavaThreadPriority, false, EXPERIMENTAL, \ 1682 "Java thread priority 10 maps to critical scheduling priority") \ 1683 \ 1684 product(bool, UseCriticalCompilerThreadPriority, false, EXPERIMENTAL, \ 1685 "Compiler thread(s) run at critical scheduling priority") \ 1686 \ 1687 develop(intx, NewCodeParameter, 0, \ 1688 "Testing Only: Create a dedicated integer parameter before " \ 1689 "putback") \ 1690 \ 1691 /* new oopmap storage allocation */ \ 1692 develop(intx, MinOopMapAllocation, 8, \ 1693 "Minimum number of OopMap entries in an OopMapSet") \ 1694 \ 1695 /* recompilation */ \ 1696 product_pd(intx, CompileThreshold, \ 1697 "number of interpreted method invocations before (re-)compiling") \ 1698 constraint(CompileThresholdConstraintFunc, AfterErgo) \ 1699 \ 1700 product_pd(bool, TieredCompilation, \ 1701 "Enable tiered compilation") \ 1702 \ 1703 /* Properties for Java libraries */ \ 1704 \ 1705 product(uint64_t, MaxDirectMemorySize, 0, \ 1706 "Maximum total size of NIO direct-buffer allocations. " \ 1707 "Ignored if not explicitly set.") \ 1708 range(0, max_jlong) \ 1709 \ 1710 /* Flags used for temporary code during development */ \ 1711 \ 1712 product(bool, UseNewCode, false, DIAGNOSTIC, \ 1713 "Testing Only: Use the new version while testing") \ 1714 \ 1715 product(bool, UseNewCode2, false, DIAGNOSTIC, \ 1716 "Testing Only: Use the new version while testing") \ 1717 \ 1718 product(bool, UseNewCode3, false, DIAGNOSTIC, \ 1719 "Testing Only: Use the new version while testing") \ 1720 \ 1721 notproduct(bool, UseDebuggerErgo, false, \ 1722 "Debugging Only: Adjust the VM to be more debugger-friendly. " \ 1723 "Turns on the other UseDebuggerErgo* flags") \ 1724 \ 1725 notproduct(bool, UseDebuggerErgo1, false, \ 1726 "Debugging Only: Enable workarounds for debugger induced " \ 1727 "os::processor_id() >= os::processor_count() problems") \ 1728 \ 1729 notproduct(bool, UseDebuggerErgo2, false, \ 1730 "Debugging Only: Limit the number of spawned JVM threads") \ 1731 \ 1732 notproduct(bool, EnableJVMTIStackDepthAsserts, true, \ 1733 "Enable JVMTI asserts related to stack depth checks") \ 1734 \ 1735 /* flags for performance data collection */ \ 1736 \ 1737 product(bool, UsePerfData, true, \ 1738 "Flag to disable jvmstat instrumentation for performance testing "\ 1739 "and problem isolation purposes") \ 1740 \ 1741 product(bool, PerfDataSaveToFile, false, \ 1742 "Save PerfData memory to hsperfdata_<pid> file on exit") \ 1743 \ 1744 product(ccstr, PerfDataSaveFile, nullptr, \ 1745 "Save PerfData memory to the specified absolute pathname. " \ 1746 "The string %p in the file name (if present) " \ 1747 "will be replaced by pid") \ 1748 \ 1749 product(int, PerfDataSamplingInterval, 50, \ 1750 "Data sampling interval (in milliseconds)") \ 1751 range(PeriodicTask::min_interval, max_jint) \ 1752 constraint(PerfDataSamplingIntervalFunc, AfterErgo) \ 1753 \ 1754 product(bool, PerfDisableSharedMem, false, \ 1755 "Store performance data in standard memory") \ 1756 \ 1757 product(int, PerfDataMemorySize, 32*K, \ 1758 "Size of performance data memory region. Will be rounded " \ 1759 "up to a multiple of the native os page size.") \ 1760 range(128, 32*64*K) \ 1761 \ 1762 product(int, PerfMaxStringConstLength, 1024, \ 1763 "Maximum PerfStringConstant string length before truncation") \ 1764 range(32, 32*K) \ 1765 \ 1766 product(bool, PerfAllowAtExitRegistration, false, \ 1767 "Allow registration of atexit() methods") \ 1768 \ 1769 product(bool, PerfBypassFileSystemCheck, false, \ 1770 "Bypass Win32 file system criteria checks (Windows Only)") \ 1771 \ 1772 product(int, UnguardOnExecutionViolation, 0, \ 1773 "Unguard page and retry on no-execute fault (Win32 only) " \ 1774 "0=off, 1=conservative, 2=aggressive") \ 1775 range(0, 2) \ 1776 \ 1777 /* Serviceability Support */ \ 1778 \ 1779 product(bool, ManagementServer, false, \ 1780 "Create JMX Management Server") \ 1781 \ 1782 product(bool, DisableAttachMechanism, false, \ 1783 "Disable mechanism that allows tools to attach to this VM") \ 1784 \ 1785 product(bool, StartAttachListener, false, \ 1786 "Always start Attach Listener at VM startup") \ 1787 \ 1788 product(bool, EnableDynamicAgentLoading, true, \ 1789 "Allow tools to load agents with the attach mechanism") \ 1790 \ 1791 product(bool, PrintConcurrentLocks, false, MANAGEABLE, \ 1792 "Print java.util.concurrent locks in thread dump") \ 1793 \ 1794 product(bool, PrintMethodHandleStubs, false, DIAGNOSTIC, \ 1795 "Print generated stub code for method handles") \ 1796 \ 1797 product(bool, VerifyMethodHandles, trueInDebug, DIAGNOSTIC, \ 1798 "perform extra checks when constructing method handles") \ 1799 \ 1800 product(bool, ShowHiddenFrames, false, DIAGNOSTIC, \ 1801 "show method handle implementation frames (usually hidden)") \ 1802 \ 1803 product(bool, ShowCarrierFrames, false, DIAGNOSTIC, \ 1804 "show virtual threads' carrier frames in exceptions") \ 1805 \ 1806 product(bool, TrustFinalNonStaticFields, false, EXPERIMENTAL, \ 1807 "trust final non-static declarations for constant folding") \ 1808 \ 1809 product(bool, FoldStableValues, true, DIAGNOSTIC, \ 1810 "Optimize loads from stable fields (marked w/ @Stable)") \ 1811 \ 1812 product(int, UseBootstrapCallInfo, 1, DIAGNOSTIC, \ 1813 "0: when resolving InDy or ConDy, force all BSM arguments to be " \ 1814 "resolved before the bootstrap method is called; 1: when a BSM " \ 1815 "that may accept a BootstrapCallInfo is detected, use that API " \ 1816 "to pass BSM arguments, which allows the BSM to delay their " \ 1817 "resolution; 2+: stress test the BCI API by calling more BSMs " \ 1818 "via that API, instead of with the eagerly-resolved array.") \ 1819 \ 1820 product(bool, PauseAtStartup, false, DIAGNOSTIC, \ 1821 "Causes the VM to pause at startup time and wait for the pause " \ 1822 "file to be removed (default: ./vm.paused.<pid>)") \ 1823 \ 1824 product(ccstr, PauseAtStartupFile, nullptr, DIAGNOSTIC, \ 1825 "The file to create and for whose removal to await when pausing " \ 1826 "at startup. (default: ./vm.paused.<pid>)") \ 1827 \ 1828 product(bool, PauseAtExit, false, DIAGNOSTIC, \ 1829 "Pause and wait for keypress on exit if a debugger is attached") \ 1830 \ 1831 product(bool, DTraceMethodProbes, false, \ 1832 "Enable dtrace tool probes for method-entry and method-exit") \ 1833 \ 1834 product(bool, DTraceAllocProbes, false, \ 1835 "Enable dtrace tool probes for object allocation") \ 1836 \ 1837 product(bool, DTraceMonitorProbes, false, \ 1838 "Enable dtrace tool probes for monitor events") \ 1839 \ 1840 product(bool, RelaxAccessControlCheck, false, \ 1841 "Relax the access control checks in the verifier") \ 1842 \ 1843 product(uintx, StringTableSize, defaultStringTableSize, \ 1844 "Number of buckets in the interned String table " \ 1845 "(will be rounded to nearest higher power of 2)") \ 1846 range(minimumStringTableSize, 16777216ul /* 2^24 */) \ 1847 \ 1848 product(uintx, SymbolTableSize, defaultSymbolTableSize, EXPERIMENTAL, \ 1849 "Number of buckets in the JVM internal Symbol table") \ 1850 range(minimumSymbolTableSize, 16777216ul /* 2^24 */) \ 1851 \ 1852 product(bool, UseStringDeduplication, false, \ 1853 "Use string deduplication") \ 1854 \ 1855 product(uint, StringDeduplicationAgeThreshold, 3, \ 1856 "A string must reach this age (or be promoted to an old region) " \ 1857 "to be considered for deduplication") \ 1858 range(1, markWord::max_age) \ 1859 \ 1860 product(size_t, StringDeduplicationInitialTableSize, 500, EXPERIMENTAL, \ 1861 "Approximate initial number of buckets in the table") \ 1862 range(1, 1 * G) \ 1863 \ 1864 product(double, StringDeduplicationGrowTableLoad, 14.0, EXPERIMENTAL, \ 1865 "Entries per bucket above which the table should be expanded") \ 1866 range(0.1, 1000.0) \ 1867 \ 1868 product(double, StringDeduplicationShrinkTableLoad, 1.0, EXPERIMENTAL, \ 1869 "Entries per bucket below which the table should be shrunk") \ 1870 range(0.01, 100.0) \ 1871 \ 1872 product(double, StringDeduplicationTargetTableLoad, 7.0, EXPERIMENTAL, \ 1873 "Desired entries per bucket when resizing the table") \ 1874 range(0.01, 1000.0) \ 1875 \ 1876 product(size_t, StringDeduplicationCleanupDeadMinimum, 100, EXPERIMENTAL, \ 1877 "Minimum number of dead table entries for cleaning the table") \ 1878 \ 1879 product(int, StringDeduplicationCleanupDeadPercent, 5, EXPERIMENTAL, \ 1880 "Minimum percentage of dead table entries for cleaning the table") \ 1881 range(1, 100) \ 1882 \ 1883 product(bool, StringDeduplicationResizeALot, false, DIAGNOSTIC, \ 1884 "Force more frequent table resizing") \ 1885 \ 1886 product(uint64_t, StringDeduplicationHashSeed, 0, DIAGNOSTIC, \ 1887 "Seed for the table hashing function; 0 requests computed seed") \ 1888 \ 1889 product(bool, WhiteBoxAPI, false, DIAGNOSTIC, \ 1890 "Enable internal testing APIs") \ 1891 \ 1892 product(size_t, ArrayAllocatorMallocLimit, SIZE_MAX, EXPERIMENTAL, \ 1893 "Allocation less than this value will be allocated " \ 1894 "using malloc. Larger allocations will use mmap.") \ 1895 \ 1896 product(bool, AlwaysAtomicAccesses, false, EXPERIMENTAL, \ 1897 "Accesses to all variables should always be atomic") \ 1898 \ 1899 product(bool, UseUnalignedAccesses, false, DIAGNOSTIC, \ 1900 "Use unaligned memory accesses in Unsafe") \ 1901 \ 1902 product_pd(bool, PreserveFramePointer, \ 1903 "Use the FP register for holding the frame pointer " \ 1904 "and not as a general purpose register.") \ 1905 \ 1906 product(size_t, AsyncLogBufferSize, 2*M, \ 1907 "Memory budget (in bytes) for the buffer of Asynchronous " \ 1908 "Logging (-Xlog:async).") \ 1909 range(100*K, 50*M) \ 1910 \ 1911 product(bool, CheckIntrinsics, true, DIAGNOSTIC, \ 1912 "When a class C is loaded, check that " \ 1913 "(1) all intrinsics defined by the VM for class C are present "\ 1914 "in the loaded class file and are marked with the " \ 1915 "@IntrinsicCandidate annotation, that " \ 1916 "(2) there is an intrinsic registered for all loaded methods " \ 1917 "that are annotated with the @IntrinsicCandidate annotation, " \ 1918 "and that " \ 1919 "(3) no orphan methods exist for class C (i.e., methods for " \ 1920 "which the VM declares an intrinsic but that are not declared "\ 1921 "in the loaded class C. " \ 1922 "Check (3) is available only in debug builds.") \ 1923 \ 1924 product_pd(intx, InitArrayShortSize, DIAGNOSTIC, \ 1925 "Threshold small size (in bytes) for clearing arrays. " \ 1926 "Anything this size or smaller may get converted to discrete " \ 1927 "scalar stores.") \ 1928 range(0, max_intx) \ 1929 constraint(InitArrayShortSizeConstraintFunc, AfterErgo) \ 1930 \ 1931 product(ccstr, AllocateHeapAt, nullptr, \ 1932 "Path to the directory where a temporary file will be created " \ 1933 "to use as the backing store for Java Heap.") \ 1934 \ 1935 product_pd(bool, VMContinuations, EXPERIMENTAL, \ 1936 "Enable VM continuations support") \ 1937 \ 1938 develop(bool, LoomDeoptAfterThaw, false, \ 1939 "Deopt stack after thaw") \ 1940 \ 1941 develop(bool, LoomVerifyAfterThaw, false, \ 1942 "Verify stack after thaw") \ 1943 \ 1944 develop(bool, VerifyContinuations, false, \ 1945 "Verify continuation consistency") \ 1946 \ 1947 develop(bool, UseContinuationFastPath, true, \ 1948 "Use fast-path frame walking in continuations") \ 1949 \ 1950 develop(int, VerifyMetaspaceInterval, DEBUG_ONLY(500) NOT_DEBUG(0), \ 1951 "Run periodic metaspace verifications (0 - none, " \ 1952 "1 - always, >1 every nth interval)") \ 1953 \ 1954 product(bool, ShowRegistersOnAssert, true, DIAGNOSTIC, \ 1955 "On internal errors, include registers in error report.") \ 1956 \ 1957 product(bool, UseSwitchProfiling, true, DIAGNOSTIC, \ 1958 "leverage profiling for table/lookup switch") \ 1959 \ 1960 develop(bool, TraceMemoryWriteback, false, \ 1961 "Trace memory writeback operations") \ 1962 \ 1963 JFR_ONLY(product(bool, FlightRecorder, false, \ 1964 "(Deprecated) Enable Flight Recorder")) \ 1965 \ 1966 JFR_ONLY(product(ccstr, FlightRecorderOptions, nullptr, \ 1967 "Flight Recorder options")) \ 1968 \ 1969 JFR_ONLY(product(ccstr, StartFlightRecording, nullptr, \ 1970 "Start flight recording with options")) \ 1971 \ 1972 product(bool, UseFastUnorderedTimeStamps, false, EXPERIMENTAL, \ 1973 "Use platform unstable time where supported for timestamps only") \ 1974 \ 1975 product(bool, UseEmptySlotsInSupers, true, \ 1976 "Allow allocating fields in empty slots of super-classes") \ 1977 \ 1978 product(bool, DeoptimizeNMethodBarriersALot, false, DIAGNOSTIC, \ 1979 "Make nmethod barriers deoptimise a lot.") \ 1980 \ 1981 develop(bool, VerifyCrossModifyFence, \ 1982 false AARCH64_ONLY(DEBUG_ONLY(||true)), \ 1983 "Mark all threads after a safepoint, and clear on a modify " \ 1984 "fence. Add cleanliness checks.") \ 1985 \ 1986 product(bool, HeapObjectStats, false, DIAGNOSTIC, \ 1987 "Enable gathering of heap object statistics") \ 1988 \ 1989 product(size_t, HeapObjectStatsSamplingInterval, 500, DIAGNOSTIC, \ 1990 "Heap object statistics sampling interval (ms)") \ 1991 \ 1992 product(int, LockingMode, LM_LEGACY, EXPERIMENTAL, \ 1993 "Select locking mode: " \ 1994 "0: monitors only (LM_MONITOR), " \ 1995 "1: monitors & legacy stack-locking (LM_LEGACY, default), " \ 1996 "2: monitors & new lightweight locking (LM_LIGHTWEIGHT)") \ 1997 range(0, 2) \ 1998 \ 1999 product(uint, TrimNativeHeapInterval, 0, EXPERIMENTAL, \ 2000 "Interval, in ms, at which the JVM will trim the native heap if " \ 2001 "the platform supports that. Lower values will reclaim memory " \ 2002 "more eagerly at the cost of higher overhead. A value of 0 " \ 2003 "(default) disables native heap trimming.") \ 2004 range(0, UINT_MAX) \ 2005 2006 // end of RUNTIME_FLAGS 2007 2008 DECLARE_FLAGS(LP64_RUNTIME_FLAGS) 2009 DECLARE_ARCH_FLAGS(ARCH_FLAGS) 2010 DECLARE_FLAGS(RUNTIME_FLAGS) 2011 DECLARE_FLAGS(RUNTIME_OS_FLAGS) 2012 2013 #endif // SHARE_RUNTIME_GLOBALS_HPP