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