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(int, ObjectAlignmentInBytes, 8, \ 134 "Default object alignment in bytes, 8 is minimum") \ 135 range(8, 256) \ 136 constraint(ObjectAlignmentInBytesConstraintFunc, AtParse) 137 138 #else 139 // !_LP64 140 141 #define LP64_RUNTIME_FLAGS(develop, \ 142 develop_pd, \ 143 product, \ 144 product_pd, \ 145 notproduct, \ 146 range, \ 147 constraint) 148 const bool UseCompressedOops = false; 149 const bool UseCompressedClassPointers = false; 150 const int ObjectAlignmentInBytes = 8; 151 152 #endif // _LP64 153 154 #define RUNTIME_FLAGS(develop, \ 155 develop_pd, \ 156 product, \ 157 product_pd, \ 158 notproduct, \ 159 range, \ 160 constraint) \ 161 \ 162 notproduct(bool, CheckCompressedOops, true, \ 163 "Generate checks in encoding/decoding code in debug VM") \ 164 \ 165 product(uintx, HeapSearchSteps, 3 PPC64_ONLY(+17), \ 166 "Heap allocation steps through preferred address regions to find" \ 167 " where it can allocate the heap. Number of steps to take per " \ 168 "region.") \ 169 range(1, max_uintx) \ 170 \ 171 product(uint, HandshakeTimeout, 0, DIAGNOSTIC, \ 172 "If nonzero set a timeout in milliseconds for handshakes") \ 173 \ 174 product(bool, AlwaysSafeConstructors, false, EXPERIMENTAL, \ 175 "Force safe construction, as if all fields are final.") \ 176 \ 177 product(bool, UnlockDiagnosticVMOptions, trueInDebug, DIAGNOSTIC, \ 178 "Enable normal processing of flags relating to field diagnostics")\ 179 \ 180 product(bool, UnlockExperimentalVMOptions, false, EXPERIMENTAL, \ 181 "Enable normal processing of flags relating to experimental " \ 182 "features") \ 183 \ 184 product(bool, JavaMonitorsInStackTrace, true, \ 185 "Print information about Java monitor locks when the stacks are " \ 186 "dumped") \ 187 \ 188 product_pd(bool, UseLargePages, \ 189 "Use large page memory") \ 190 \ 191 product_pd(bool, UseLargePagesIndividualAllocation, \ 192 "Allocate large pages individually for better affinity") \ 193 \ 194 develop(bool, LargePagesIndividualAllocationInjectError, false, \ 195 "Fail large pages individual allocation") \ 196 \ 197 product(bool, UseNUMA, false, \ 198 "Use NUMA if available") \ 199 \ 200 product(bool, UseNUMAInterleaving, false, \ 201 "Interleave memory across NUMA nodes if available") \ 202 \ 203 product(size_t, NUMAInterleaveGranularity, 2*M, \ 204 "Granularity to use for NUMA interleaving on Windows OS") \ 205 constraint(NUMAInterleaveGranularityConstraintFunc, AtParse) \ 206 \ 207 product(uintx, NUMAChunkResizeWeight, 20, \ 208 "Percentage (0-100) used to weight the current sample when " \ 209 "computing exponentially decaying average for " \ 210 "AdaptiveNUMAChunkSizing") \ 211 range(0, 100) \ 212 \ 213 product(size_t, NUMASpaceResizeRate, 1*G, \ 214 "Do not reallocate more than this amount per collection") \ 215 range(0, max_uintx) \ 216 \ 217 product(bool, UseAdaptiveNUMAChunkSizing, true, \ 218 "Enable adaptive chunk sizing for NUMA") \ 219 \ 220 product(bool, NUMAStats, false, \ 221 "Print NUMA stats in detailed heap information") \ 222 \ 223 product(uintx, NUMAPageScanRate, 256, \ 224 "Maximum number of pages to include in the page scan procedure") \ 225 range(0, max_uintx) \ 226 \ 227 product(bool, UseAES, false, \ 228 "Control whether AES instructions are used when available") \ 229 \ 230 product(bool, UseFMA, false, \ 231 "Control whether FMA instructions are used when available") \ 232 \ 233 product(bool, UseSHA, false, \ 234 "Control whether SHA instructions are used when available") \ 235 \ 236 product(bool, UseGHASHIntrinsics, false, DIAGNOSTIC, \ 237 "Use intrinsics for GHASH versions of crypto") \ 238 \ 239 product(bool, UseBASE64Intrinsics, false, \ 240 "Use intrinsics for java.util.Base64") \ 241 \ 242 product(bool, UsePoly1305Intrinsics, false, DIAGNOSTIC, \ 243 "Use intrinsics for sun.security.util.math.intpoly") \ 244 \ 245 product(size_t, LargePageSizeInBytes, 0, \ 246 "Maximum large page size used (0 will use the default large " \ 247 "page size for the environment as the maximum)") \ 248 range(0, max_uintx) \ 249 \ 250 product(size_t, LargePageHeapSizeThreshold, 128*M, \ 251 "Use large pages if maximum heap is at least this big") \ 252 range(0, max_uintx) \ 253 \ 254 product(bool, ForceTimeHighResolution, false, \ 255 "Using high time resolution (for Win32 only)") \ 256 \ 257 develop(bool, TracePcPatching, false, \ 258 "Trace usage of frame::patch_pc") \ 259 \ 260 develop(bool, TraceRelocator, false, \ 261 "Trace the bytecode relocator") \ 262 \ 263 \ 264 product(bool, SafepointALot, false, DIAGNOSTIC, \ 265 "Generate a lot of safepoints. This works with " \ 266 "GuaranteedSafepointInterval") \ 267 \ 268 product(bool, HandshakeALot, false, DIAGNOSTIC, \ 269 "Generate a lot of handshakes. This works with " \ 270 "GuaranteedSafepointInterval") \ 271 \ 272 product_pd(bool, BackgroundCompilation, \ 273 "A thread requesting compilation is not blocked during " \ 274 "compilation") \ 275 \ 276 product(bool, MethodFlushing, true, \ 277 "Reclamation of compiled methods") \ 278 \ 279 develop(bool, VerifyStack, false, \ 280 "Verify stack of each thread when it is entering a runtime call") \ 281 \ 282 product(bool, ForceUnreachable, false, DIAGNOSTIC, \ 283 "Make all non code cache addresses to be unreachable by " \ 284 "forcing use of 64bit literal fixups") \ 285 \ 286 develop(bool, TraceDerivedPointers, false, \ 287 "Trace traversal of derived pointers on stack") \ 288 \ 289 notproduct(bool, TraceCodeBlobStacks, false, \ 290 "Trace stack-walk of codeblobs") \ 291 \ 292 notproduct(bool, PrintRewrites, false, \ 293 "Print methods that are being rewritten") \ 294 \ 295 product(bool, UseInlineCaches, true, \ 296 "Use Inline Caches for virtual calls ") \ 297 \ 298 product(bool, InlineArrayCopy, true, DIAGNOSTIC, \ 299 "Inline arraycopy native that is known to be part of " \ 300 "base library DLL") \ 301 \ 302 product(bool, InlineObjectHash, true, DIAGNOSTIC, \ 303 "Inline Object::hashCode() native that is known to be part " \ 304 "of base library DLL") \ 305 \ 306 product(bool, InlineNatives, true, DIAGNOSTIC, \ 307 "Inline natives that are known to be part of base library DLL") \ 308 \ 309 product(bool, InlineMathNatives, true, DIAGNOSTIC, \ 310 "Inline SinD, CosD, etc.") \ 311 \ 312 product(bool, InlineClassNatives, true, DIAGNOSTIC, \ 313 "Inline Class.isInstance, etc") \ 314 \ 315 product(bool, InlineThreadNatives, true, DIAGNOSTIC, \ 316 "Inline Thread.currentThread, etc") \ 317 \ 318 product(bool, InlineUnsafeOps, true, DIAGNOSTIC, \ 319 "Inline memory ops (native methods) from Unsafe") \ 320 \ 321 product(bool, UseAESIntrinsics, false, DIAGNOSTIC, \ 322 "Use intrinsics for AES versions of crypto") \ 323 \ 324 product(bool, UseAESCTRIntrinsics, false, DIAGNOSTIC, \ 325 "Use intrinsics for the paralleled version of AES/CTR crypto") \ 326 \ 327 product(bool, UseChaCha20Intrinsics, false, DIAGNOSTIC, \ 328 "Use intrinsics for the vectorized version of ChaCha20") \ 329 \ 330 product(bool, UseMD5Intrinsics, false, DIAGNOSTIC, \ 331 "Use intrinsics for MD5 crypto hash function") \ 332 \ 333 product(bool, UseSHA1Intrinsics, false, DIAGNOSTIC, \ 334 "Use intrinsics for SHA-1 crypto hash function. " \ 335 "Requires that UseSHA is enabled.") \ 336 \ 337 product(bool, UseSHA256Intrinsics, false, DIAGNOSTIC, \ 338 "Use intrinsics for SHA-224 and SHA-256 crypto hash functions. " \ 339 "Requires that UseSHA is enabled.") \ 340 \ 341 product(bool, UseSHA512Intrinsics, false, DIAGNOSTIC, \ 342 "Use intrinsics for SHA-384 and SHA-512 crypto hash functions. " \ 343 "Requires that UseSHA is enabled.") \ 344 \ 345 product(bool, UseSHA3Intrinsics, false, DIAGNOSTIC, \ 346 "Use intrinsics for SHA3 crypto hash function. " \ 347 "Requires that UseSHA is enabled.") \ 348 \ 349 product(bool, UseCRC32Intrinsics, false, DIAGNOSTIC, \ 350 "use intrinsics for java.util.zip.CRC32") \ 351 \ 352 product(bool, UseCRC32CIntrinsics, false, DIAGNOSTIC, \ 353 "use intrinsics for java.util.zip.CRC32C") \ 354 \ 355 product(bool, UseAdler32Intrinsics, false, DIAGNOSTIC, \ 356 "use intrinsics for java.util.zip.Adler32") \ 357 \ 358 product(bool, UseVectorizedMismatchIntrinsic, false, DIAGNOSTIC, \ 359 "Enables intrinsification of ArraysSupport.vectorizedMismatch()") \ 360 \ 361 product(bool, UseVectorizedHashCodeIntrinsic, false, DIAGNOSTIC, \ 362 "Enables intrinsification of ArraysSupport.vectorizedHashCode()") \ 363 \ 364 product(bool, UseCopySignIntrinsic, false, DIAGNOSTIC, \ 365 "Enables intrinsification of Math.copySign") \ 366 \ 367 product(bool, UseSignumIntrinsic, false, DIAGNOSTIC, \ 368 "Enables intrinsification of Math.signum") \ 369 \ 370 product_pd(bool, DelayCompilerStubsGeneration, DIAGNOSTIC, \ 371 "Use Compiler thread for compiler's stubs generation") \ 372 \ 373 product(ccstrlist, DisableIntrinsic, "", DIAGNOSTIC, \ 374 "do not expand intrinsics whose (internal) names appear here") \ 375 constraint(DisableIntrinsicConstraintFunc,AfterErgo) \ 376 \ 377 product(ccstrlist, ControlIntrinsic, "", DIAGNOSTIC, \ 378 "Control intrinsics using a list of +/- (internal) names, " \ 379 "separated by commas") \ 380 constraint(ControlIntrinsicConstraintFunc,AfterErgo) \ 381 \ 382 develop(bool, TraceCallFixup, false, \ 383 "Trace all call fixups") \ 384 \ 385 develop(bool, DeoptimizeALot, false, \ 386 "Deoptimize at every exit from the runtime system") \ 387 \ 388 notproduct(ccstrlist, DeoptimizeOnlyAt, "", \ 389 "A comma separated list of bcis to deoptimize at") \ 390 \ 391 develop(bool, DeoptimizeRandom, false, \ 392 "Deoptimize random frames on random exit from the runtime system")\ 393 \ 394 notproduct(bool, ZombieALot, false, \ 395 "Create non-entrant nmethods at exit from the runtime system") \ 396 \ 397 notproduct(bool, WalkStackALot, false, \ 398 "Trace stack (no print) at every exit from the runtime system") \ 399 \ 400 develop(bool, DeoptimizeObjectsALot, false, \ 401 "For testing purposes concurrent threads revert optimizations " \ 402 "based on escape analysis at intervals given with " \ 403 "DeoptimizeObjectsALotInterval=n. The thread count is given " \ 404 "with DeoptimizeObjectsALotThreadCountSingle and " \ 405 "DeoptimizeObjectsALotThreadCountAll.") \ 406 \ 407 develop(uint64_t, DeoptimizeObjectsALotInterval, 5, \ 408 "Interval for DeoptimizeObjectsALot.") \ 409 range(0, max_jlong) \ 410 \ 411 develop(int, DeoptimizeObjectsALotThreadCountSingle, 1, \ 412 "The number of threads that revert optimizations based on " \ 413 "escape analysis for a single thread if DeoptimizeObjectsALot " \ 414 "is enabled. The target thread is selected round robin." ) \ 415 range(0, max_jint) \ 416 \ 417 develop(int, DeoptimizeObjectsALotThreadCountAll, 1, \ 418 "The number of threads that revert optimizations based on " \ 419 "escape analysis for all threads if DeoptimizeObjectsALot " \ 420 "is enabled." ) \ 421 range(0, max_jint) \ 422 \ 423 notproduct(bool, VerifyLastFrame, false, \ 424 "Verify oops on last frame on entry to VM") \ 425 \ 426 product(bool, SafepointTimeout, false, \ 427 "Time out and warn or fail after SafepointTimeoutDelay " \ 428 "milliseconds if failed to reach safepoint") \ 429 \ 430 product(bool, AbortVMOnSafepointTimeout, false, DIAGNOSTIC, \ 431 "Abort upon failure to reach safepoint (see SafepointTimeout)") \ 432 \ 433 product(bool, AbortVMOnVMOperationTimeout, false, DIAGNOSTIC, \ 434 "Abort upon failure to complete VM operation promptly") \ 435 \ 436 product(intx, AbortVMOnVMOperationTimeoutDelay, 1000, DIAGNOSTIC, \ 437 "Delay in milliseconds for option AbortVMOnVMOperationTimeout") \ 438 range(0, max_intx) \ 439 \ 440 product(bool, MaxFDLimit, true, \ 441 "Bump the number of file descriptors to maximum (Unix only)") \ 442 \ 443 product(bool, LogEvents, true, DIAGNOSTIC, \ 444 "Enable the various ring buffer event logs") \ 445 \ 446 product(uintx, LogEventsBufferEntries, 20, DIAGNOSTIC, \ 447 "Number of ring buffer event logs") \ 448 range(1, NOT_LP64(1*K) LP64_ONLY(1*M)) \ 449 \ 450 product(bool, BytecodeVerificationRemote, true, DIAGNOSTIC, \ 451 "Enable the Java bytecode verifier for remote classes") \ 452 \ 453 product(bool, BytecodeVerificationLocal, false, DIAGNOSTIC, \ 454 "Enable the Java bytecode verifier for local classes") \ 455 \ 456 develop(bool, VerifyStackAtCalls, false, \ 457 "Verify that the stack pointer is unchanged after calls") \ 458 \ 459 develop(bool, TraceJavaAssertions, false, \ 460 "Trace java language assertions") \ 461 \ 462 notproduct(bool, VerifyCodeCache, false, \ 463 "Verify code cache on memory allocation/deallocation") \ 464 \ 465 develop(bool, ZapResourceArea, trueInDebug, \ 466 "Zap freed resource/arena space") \ 467 \ 468 notproduct(bool, ZapVMHandleArea, trueInDebug, \ 469 "Zap freed VM handle space") \ 470 \ 471 notproduct(bool, ZapStackSegments, trueInDebug, \ 472 "Zap allocated/freed stack segments") \ 473 \ 474 develop(bool, ZapUnusedHeapArea, trueInDebug, \ 475 "Zap unused heap space") \ 476 \ 477 develop(bool, CheckZapUnusedHeapArea, false, \ 478 "Check zapping of unused heap space") \ 479 \ 480 develop(bool, ZapFillerObjects, trueInDebug, \ 481 "Zap filler objects") \ 482 \ 483 product(bool, ExecutingUnitTests, false, \ 484 "Whether the JVM is running unit tests or not") \ 485 \ 486 develop(uint, ErrorHandlerTest, 0, \ 487 "If > 0, provokes an error after VM initialization; the value " \ 488 "determines which error to provoke. See controlled_crash() " \ 489 "in vmError.cpp.") \ 490 range(0, 17) \ 491 \ 492 develop(uint, TestCrashInErrorHandler, 0, \ 493 "If > 0, provokes an error inside VM error handler (a secondary " \ 494 "crash). see controlled_crash() in vmError.cpp") \ 495 range(0, 17) \ 496 \ 497 develop(bool, TestSafeFetchInErrorHandler, false , \ 498 "If true, tests SafeFetch inside error handler.") \ 499 \ 500 develop(bool, TestUnresponsiveErrorHandler, false, \ 501 "If true, simulates an unresponsive error handler.") \ 502 \ 503 develop(bool, Verbose, false, \ 504 "Print additional debugging information from other modes") \ 505 \ 506 develop(bool, PrintMiscellaneous, false, \ 507 "Print uncategorized debugging information (requires +Verbose)") \ 508 \ 509 develop(bool, WizardMode, false, \ 510 "Print much more debugging information") \ 511 \ 512 product(bool, ShowMessageBoxOnError, false, \ 513 "Keep process alive on VM fatal error") \ 514 \ 515 product(bool, CreateCoredumpOnCrash, true, \ 516 "Create core/mini dump on VM fatal error") \ 517 \ 518 product(uint64_t, ErrorLogTimeout, 2 * 60, \ 519 "Timeout, in seconds, to limit the time spent on writing an " \ 520 "error log in case of a crash.") \ 521 range(0, (uint64_t)max_jlong/1000) \ 522 \ 523 product(bool, ErrorLogSecondaryErrorDetails, false, DIAGNOSTIC, \ 524 "If enabled, show details on secondary crashes in the error log") \ 525 \ 526 develop(intx, TraceDwarfLevel, 0, \ 527 "Debug levels for the dwarf parser") \ 528 range(0, 4) \ 529 \ 530 product(bool, SuppressFatalErrorMessage, false, \ 531 "Report NO fatal error message (avoid deadlock)") \ 532 \ 533 product(ccstrlist, OnError, "", \ 534 "Run user-defined commands on fatal error; see VMError.cpp " \ 535 "for examples") \ 536 \ 537 product(ccstrlist, OnOutOfMemoryError, "", \ 538 "Run user-defined commands on first java.lang.OutOfMemoryError " \ 539 "thrown from JVM") \ 540 \ 541 product(bool, HeapDumpBeforeFullGC, false, MANAGEABLE, \ 542 "Dump heap to file before any major stop-the-world GC") \ 543 \ 544 product(bool, HeapDumpAfterFullGC, false, MANAGEABLE, \ 545 "Dump heap to file after any major stop-the-world GC") \ 546 \ 547 product(bool, HeapDumpOnOutOfMemoryError, false, MANAGEABLE, \ 548 "Dump heap to file when java.lang.OutOfMemoryError is thrown " \ 549 "from JVM") \ 550 \ 551 product(ccstr, HeapDumpPath, nullptr, MANAGEABLE, \ 552 "When HeapDumpOnOutOfMemoryError is on, the path (filename or " \ 553 "directory) of the dump file (defaults to java_pid<pid>.hprof " \ 554 "in the working directory)") \ 555 \ 556 product(intx, HeapDumpGzipLevel, 0, MANAGEABLE, \ 557 "When HeapDumpOnOutOfMemoryError is on, the gzip compression " \ 558 "level of the dump file. 0 (the default) disables gzip " \ 559 "compression. Otherwise the level must be between 1 and 9.") \ 560 range(0, 9) \ 561 \ 562 product(ccstr, NativeMemoryTracking, DEBUG_ONLY("summary") NOT_DEBUG("off"), \ 563 "Native memory tracking options") \ 564 \ 565 product(bool, PrintNMTStatistics, false, DIAGNOSTIC, \ 566 "Print native memory tracking summary data if it is on") \ 567 \ 568 product(bool, LogCompilation, false, DIAGNOSTIC, \ 569 "Log compilation activity in detail to LogFile") \ 570 \ 571 product(bool, PrintCompilation, false, \ 572 "Print compilations") \ 573 \ 574 product(intx, RepeatCompilation, 0, DIAGNOSTIC, \ 575 "Repeat compilation without installing code (number of times)") \ 576 range(0, max_jint) \ 577 \ 578 product(bool, PrintExtendedThreadInfo, false, \ 579 "Print more information in thread dump") \ 580 \ 581 product(intx, ScavengeRootsInCode, 2, DIAGNOSTIC, \ 582 "0: do not allow scavengable oops in the code cache; " \ 583 "1: allow scavenging from the code cache; " \ 584 "2: emit as many constants as the compiler can see") \ 585 range(0, 2) \ 586 \ 587 product(bool, AlwaysRestoreFPU, false, \ 588 "Restore the FPU control word after every JNI call (expensive)") \ 589 \ 590 product(bool, PrintCompilation2, false, DIAGNOSTIC, \ 591 "Print additional statistics per compilation") \ 592 \ 593 product(bool, PrintAdapterHandlers, false, DIAGNOSTIC, \ 594 "Print code generated for i2c/c2i adapters") \ 595 \ 596 product(bool, VerifyAdapterCalls, trueInDebug, DIAGNOSTIC, \ 597 "Verify that i2c/c2i adapters are called properly") \ 598 \ 599 develop(bool, VerifyAdapterSharing, false, \ 600 "Verify that the code for shared adapters is the equivalent") \ 601 \ 602 product(bool, PrintAssembly, false, DIAGNOSTIC, \ 603 "Print assembly code (using external disassembler.so)") \ 604 \ 605 product(ccstr, PrintAssemblyOptions, nullptr, DIAGNOSTIC, \ 606 "Print options string passed to disassembler.so") \ 607 \ 608 notproduct(bool, PrintNMethodStatistics, false, \ 609 "Print a summary statistic for the generated nmethods") \ 610 \ 611 product(bool, PrintNMethods, false, DIAGNOSTIC, \ 612 "Print assembly code for nmethods when generated") \ 613 \ 614 product(bool, PrintNativeNMethods, false, DIAGNOSTIC, \ 615 "Print assembly code for native nmethods when generated") \ 616 \ 617 develop(bool, PrintDebugInfo, false, \ 618 "Print debug information for all nmethods when generated") \ 619 \ 620 develop(bool, PrintRelocations, false, \ 621 "Print relocation information for all nmethods when generated") \ 622 \ 623 develop(bool, PrintDependencies, false, \ 624 "Print dependency information for all nmethods when generated") \ 625 \ 626 develop(bool, PrintExceptionHandlers, false, \ 627 "Print exception handler tables for all nmethods when generated") \ 628 \ 629 develop(bool, StressCompiledExceptionHandlers, false, \ 630 "Exercise compiled exception handlers") \ 631 \ 632 develop(bool, InterceptOSException, false, \ 633 "Start debugger when an implicit OS (e.g. null pointer) " \ 634 "exception happens") \ 635 \ 636 product(bool, PrintCodeCache, false, \ 637 "Print the code cache memory usage when exiting") \ 638 \ 639 develop(bool, PrintCodeCache2, false, \ 640 "Print detailed usage information on the code cache when exiting")\ 641 \ 642 product(bool, PrintCodeCacheOnCompilation, false, \ 643 "Print the code cache memory usage each time a method is " \ 644 "compiled") \ 645 \ 646 product(bool, PrintCodeHeapAnalytics, false, DIAGNOSTIC, \ 647 "Print code heap usage statistics on exit and on full condition") \ 648 \ 649 product(bool, PrintStubCode, false, DIAGNOSTIC, \ 650 "Print generated stub code") \ 651 \ 652 product(bool, StackTraceInThrowable, true, \ 653 "Collect backtrace in throwable when exception happens") \ 654 \ 655 product(bool, OmitStackTraceInFastThrow, true, \ 656 "Omit backtraces for some 'hot' exceptions in optimized code") \ 657 \ 658 product(bool, ShowCodeDetailsInExceptionMessages, true, MANAGEABLE, \ 659 "Show exception messages from RuntimeExceptions that contain " \ 660 "snippets of the failing code. Disable this to improve privacy.") \ 661 \ 662 product(bool, PrintWarnings, true, \ 663 "Print JVM warnings to output stream") \ 664 \ 665 product(bool, RegisterFinalizersAtInit, true, \ 666 "Register finalizable objects at end of Object.<init> or " \ 667 "after allocation") \ 668 \ 669 develop(bool, RegisterReferences, true, \ 670 "Tell whether the VM should register soft/weak/final/phantom " \ 671 "references") \ 672 \ 673 develop(bool, PrintCodeCacheExtension, false, \ 674 "Print extension of code cache") \ 675 \ 676 develop(bool, UsePrivilegedStack, true, \ 677 "Enable the security JVM functions") \ 678 \ 679 product(bool, ClassUnloading, true, \ 680 "Do unloading of classes") \ 681 \ 682 product(bool, ClassUnloadingWithConcurrentMark, true, \ 683 "Do unloading of classes with a concurrent marking cycle") \ 684 \ 685 notproduct(bool, PrintSystemDictionaryAtExit, false, \ 686 "Print the system dictionary at exit") \ 687 \ 688 notproduct(bool, PrintClassLoaderDataGraphAtExit, false, \ 689 "Print the class loader data graph at exit") \ 690 \ 691 product(bool, AllowParallelDefineClass, false, \ 692 "Allow parallel defineClass requests for class loaders " \ 693 "registering as parallel capable") \ 694 \ 695 product_pd(bool, DontYieldALot, \ 696 "Throw away obvious excess yield calls") \ 697 \ 698 product(bool, DisablePrimordialThreadGuardPages, false, EXPERIMENTAL, \ 699 "Disable the use of stack guard pages if the JVM is loaded " \ 700 "on the primordial process thread") \ 701 \ 702 product(bool, DoJVMTIVirtualThreadTransitions, true, EXPERIMENTAL, \ 703 "Do JVMTI virtual thread mount/unmount transitions " \ 704 "(disabling this flag implies no JVMTI events are posted)") \ 705 \ 706 /* notice: the max range value here is max_jint, not max_intx */ \ 707 /* because of overflow issue */ \ 708 product(intx, AsyncDeflationInterval, 250, DIAGNOSTIC, \ 709 "Async deflate idle monitors every so many milliseconds when " \ 710 "MonitorUsedDeflationThreshold is exceeded (0 is off).") \ 711 range(0, max_jint) \ 712 \ 713 /* notice: the max range value here is max_jint, not max_intx */ \ 714 /* because of overflow issue */ \ 715 product(intx, GuaranteedAsyncDeflationInterval, 60000, DIAGNOSTIC, \ 716 "Async deflate idle monitors every so many milliseconds even " \ 717 "when MonitorUsedDeflationThreshold is NOT exceeded (0 is off).") \ 718 range(0, max_jint) \ 719 \ 720 product(size_t, AvgMonitorsPerThreadEstimate, 1024, DIAGNOSTIC, \ 721 "Used to estimate a variable ceiling based on number of threads " \ 722 "for use with MonitorUsedDeflationThreshold (0 is off).") \ 723 range(0, max_uintx) \ 724 \ 725 /* notice: the max range value here is max_jint, not max_intx */ \ 726 /* because of overflow issue */ \ 727 product(intx, MonitorDeflationMax, 1000000, DIAGNOSTIC, \ 728 "The maximum number of monitors to deflate, unlink and delete " \ 729 "at one time (minimum is 1024).") \ 730 range(1024, max_jint) \ 731 \ 732 product(intx, MonitorUsedDeflationThreshold, 90, DIAGNOSTIC, \ 733 "Percentage of used monitors before triggering deflation (0 is " \ 734 "off). The check is performed on GuaranteedSafepointInterval, " \ 735 "AsyncDeflationInterval or GuaranteedAsyncDeflationInterval, " \ 736 "whichever is lower.") \ 737 range(0, 100) \ 738 \ 739 product(uintx, NoAsyncDeflationProgressMax, 3, DIAGNOSTIC, \ 740 "Max number of no progress async deflation attempts to tolerate " \ 741 "before adjusting the in_use_list_ceiling up (0 is off).") \ 742 range(0, max_uintx) \ 743 \ 744 product(intx, hashCode, 5, EXPERIMENTAL, \ 745 "(Unstable) select hashCode generation algorithm") \ 746 \ 747 product(bool, ReduceSignalUsage, false, \ 748 "Reduce the use of OS signals in Java and/or the VM") \ 749 \ 750 develop(bool, LoadLineNumberTables, true, \ 751 "Tell whether the class file parser loads line number tables") \ 752 \ 753 develop(bool, LoadLocalVariableTables, true, \ 754 "Tell whether the class file parser loads local variable tables") \ 755 \ 756 develop(bool, LoadLocalVariableTypeTables, true, \ 757 "Tell whether the class file parser loads local variable type" \ 758 "tables") \ 759 \ 760 product(bool, AllowUserSignalHandlers, false, \ 761 "Application will install primary signal handlers for the JVM " \ 762 "(Unix only)") \ 763 \ 764 product(bool, UseSignalChaining, true, \ 765 "Use signal-chaining to invoke signal handlers installed " \ 766 "by the application (Unix only)") \ 767 \ 768 product(bool, RestoreMXCSROnJNICalls, false, \ 769 "Restore MXCSR when returning from JNI calls") \ 770 \ 771 product(bool, CheckJNICalls, false, \ 772 "Verify all arguments to JNI calls") \ 773 \ 774 product(bool, UseFastJNIAccessors, true, \ 775 "Use optimized versions of Get<Primitive>Field") \ 776 \ 777 product(intx, MaxJNILocalCapacity, 65536, \ 778 "Maximum allowable local JNI handle capacity to " \ 779 "EnsureLocalCapacity() and PushLocalFrame(), " \ 780 "where <= 0 is unlimited, default: 65536") \ 781 range(min_intx, max_intx) \ 782 \ 783 product(bool, EagerXrunInit, false, \ 784 "Eagerly initialize -Xrun libraries; allows startup profiling, " \ 785 "but not all -Xrun libraries may support the state of the VM " \ 786 "at this time") \ 787 \ 788 product(bool, PreserveAllAnnotations, false, \ 789 "Preserve RuntimeInvisibleAnnotations as well " \ 790 "as RuntimeVisibleAnnotations") \ 791 \ 792 develop(uintx, PreallocatedOutOfMemoryErrorCount, 4, \ 793 "Number of OutOfMemoryErrors preallocated with backtrace") \ 794 \ 795 product(bool, UseXMMForArrayCopy, false, \ 796 "Use SSE2 MOVQ instruction for Arraycopy") \ 797 \ 798 notproduct(bool, PrintFieldLayout, false, \ 799 "Print field layout for each class") \ 800 \ 801 notproduct(bool, PrintInlineLayout, false, \ 802 "Print field layout for each inline type") \ 803 \ 804 notproduct(bool, PrintFlatArrayLayout, false, \ 805 "Print array layout for each inline type array") \ 806 \ 807 product(intx, FlatArrayElementMaxSize, -1, \ 808 "Max size for flattening inline array elements, <0 no limit") \ 809 \ 810 product(intx, InlineFieldMaxFlatSize, 128, \ 811 "Max size for flattening inline type fields, <0 no limit") \ 812 \ 813 product(intx, FlatArrayElementMaxOops, 4, \ 814 "Max nof embedded object references in an inline type to flatten, <0 no limit") \ 815 \ 816 product(bool, InlineArrayAtomicAccess, false, \ 817 "Atomic inline array accesses by-default, for all inline arrays") \ 818 \ 819 /* Need to limit the extent of the padding to reasonable size. */\ 820 /* 8K is well beyond the reasonable HW cache line size, even with */\ 821 /* aggressive prefetching, while still leaving the room for segregating */\ 822 /* among the distinct pages. */\ 823 product(intx, ContendedPaddingWidth, 128, \ 824 "How many bytes to pad the fields/classes marked @Contended with")\ 825 range(0, 8192) \ 826 constraint(ContendedPaddingWidthConstraintFunc,AfterErgo) \ 827 \ 828 product(bool, EnableContended, true, \ 829 "Enable @Contended annotation support") \ 830 \ 831 product(bool, RestrictContended, true, \ 832 "Restrict @Contended to trusted classes") \ 833 \ 834 product(int, DiagnoseSyncOnValueBasedClasses, 0, DIAGNOSTIC, \ 835 "Detect and take action upon identifying synchronization on " \ 836 "value based classes. Modes: " \ 837 "0: off; " \ 838 "1: exit with fatal error; " \ 839 "2: log message to stdout. Output file can be specified with " \ 840 " -Xlog:valuebasedclasses. If JFR is running it will " \ 841 " also generate JFR events.") \ 842 range(0, 2) \ 843 \ 844 product(bool, ExitOnOutOfMemoryError, false, \ 845 "JVM exits on the first occurrence of an out-of-memory error " \ 846 "thrown from JVM") \ 847 \ 848 product(bool, CrashOnOutOfMemoryError, false, \ 849 "JVM aborts, producing an error log and core/mini dump, on the " \ 850 "first occurrence of an out-of-memory error thrown from JVM") \ 851 \ 852 /* tracing */ \ 853 \ 854 develop(bool, StressRewriter, false, \ 855 "Stress linktime bytecode rewriting") \ 856 \ 857 product(ccstr, TraceJVMTI, nullptr, \ 858 "Trace flags for JVMTI functions and events") \ 859 \ 860 product(bool, StressLdcRewrite, false, DIAGNOSTIC, \ 861 "Force ldc -> ldc_w rewrite during RedefineClasses. " \ 862 "This option can change an EMCP method into an obsolete method " \ 863 "and can affect tests that expect specific methods to be EMCP. " \ 864 "This option should be used with caution.") \ 865 \ 866 product(bool, AllowRedefinitionToAddDeleteMethods, false, \ 867 "(Deprecated) Allow redefinition to add and delete private " \ 868 "static or final methods for compatibility with old releases") \ 869 \ 870 develop(bool, TraceBytecodes, false, \ 871 "Trace bytecode execution") \ 872 \ 873 develop(bool, TraceICs, false, \ 874 "Trace inline cache changes") \ 875 \ 876 notproduct(bool, TraceInvocationCounterOverflow, false, \ 877 "Trace method invocation counter overflow") \ 878 \ 879 develop(bool, TraceInlineCacheClearing, false, \ 880 "Trace clearing of inline caches in nmethods") \ 881 \ 882 develop(bool, VerifyDependencies, trueInDebug, \ 883 "Exercise and verify the compilation dependency mechanism") \ 884 \ 885 develop(bool, TraceNewOopMapGeneration, false, \ 886 "Trace OopMapGeneration") \ 887 \ 888 develop(bool, TraceNewOopMapGenerationDetailed, false, \ 889 "Trace OopMapGeneration: print detailed cell states") \ 890 \ 891 develop(bool, TimeOopMap, false, \ 892 "Time calls to GenerateOopMap::compute_map() in sum") \ 893 \ 894 develop(bool, TimeOopMap2, false, \ 895 "Time calls to GenerateOopMap::compute_map() individually") \ 896 \ 897 develop(bool, TraceOopMapRewrites, false, \ 898 "Trace rewriting of methods during oop map generation") \ 899 \ 900 develop(bool, TraceICBuffer, false, \ 901 "Trace usage of IC buffer") \ 902 \ 903 develop(bool, TraceCompiledIC, false, \ 904 "Trace changes of compiled IC") \ 905 \ 906 develop(bool, FLSVerifyDictionary, false, \ 907 "Do lots of (expensive) FLS dictionary verification") \ 908 \ 909 product(uintx, ProcessDistributionStride, 4, \ 910 "Stride through processors when distributing processes") \ 911 range(0, max_juint) \ 912 \ 913 develop(bool, TraceFinalizerRegistration, false, \ 914 "Trace registration of final references") \ 915 \ 916 product(bool, IgnoreEmptyClassPaths, false, \ 917 "Ignore empty path elements in -classpath") \ 918 \ 919 product(bool, PrintHeapAtSIGBREAK, true, \ 920 "Print heap layout in response to SIGBREAK") \ 921 \ 922 product(bool, PrintClassHistogram, false, MANAGEABLE, \ 923 "Print a histogram of class instances") \ 924 \ 925 product(double, ObjectCountCutOffPercent, 0.5, EXPERIMENTAL, \ 926 "The percentage of the used heap that the instances of a class " \ 927 "must occupy for the class to generate a trace event") \ 928 range(0.0, 100.0) \ 929 \ 930 /* JVMTI heap profiling */ \ 931 \ 932 product(bool, VerifyBeforeIteration, false, DIAGNOSTIC, \ 933 "Verify memory system before JVMTI iteration") \ 934 \ 935 /* compiler */ \ 936 \ 937 /* notice: the max range value here is max_jint, not max_intx */ \ 938 /* because of overflow issue */ \ 939 product(intx, CICompilerCount, CI_COMPILER_COUNT, \ 940 "Number of compiler threads to run") \ 941 range(0, max_jint) \ 942 constraint(CICompilerCountConstraintFunc, AfterErgo) \ 943 \ 944 product(bool, UseDynamicNumberOfCompilerThreads, true, \ 945 "Dynamically choose the number of parallel compiler threads") \ 946 \ 947 product(bool, ReduceNumberOfCompilerThreads, true, DIAGNOSTIC, \ 948 "Reduce the number of parallel compiler threads when they " \ 949 "are not used") \ 950 \ 951 product(bool, TraceCompilerThreads, false, DIAGNOSTIC, \ 952 "Trace creation and removal of compiler threads") \ 953 \ 954 product(ccstr, LogClassLoadingCauseFor, nullptr, \ 955 "Apply -Xlog:class+load+cause* to classes whose fully " \ 956 "qualified name contains this string (\"*\" matches " \ 957 "any class).") \ 958 \ 959 develop(bool, InjectCompilerCreationFailure, false, \ 960 "Inject thread creation failures for " \ 961 "UseDynamicNumberOfCompilerThreads") \ 962 \ 963 develop(bool, GenerateSynchronizationCode, true, \ 964 "generate locking/unlocking code for synchronized methods and " \ 965 "monitors") \ 966 \ 967 product_pd(bool, ImplicitNullChecks, DIAGNOSTIC, \ 968 "Generate code for implicit null checks") \ 969 \ 970 product_pd(bool, TrapBasedNullChecks, \ 971 "Generate code for null checks that uses a cmp and trap " \ 972 "instruction raising SIGTRAP. This is only used if an access to" \ 973 "null (+offset) will not raise a SIGSEGV, i.e.," \ 974 "ImplicitNullChecks don't work (PPC64).") \ 975 \ 976 product(bool, EnableThreadSMRStatistics, trueInDebug, DIAGNOSTIC, \ 977 "Enable Thread SMR Statistics") \ 978 \ 979 product(bool, UseNotificationThread, true, \ 980 "Use Notification Thread") \ 981 \ 982 product(bool, Inline, true, \ 983 "Enable inlining") \ 984 \ 985 product(bool, ClipInlining, true, \ 986 "Clip inlining if aggregate method exceeds DesiredMethodLimit") \ 987 \ 988 develop(bool, UseCHA, true, \ 989 "Enable CHA") \ 990 \ 991 product(bool, UseVtableBasedCHA, true, DIAGNOSTIC, \ 992 "Use vtable information during CHA") \ 993 \ 994 product(bool, UseTypeProfile, true, \ 995 "Check interpreter profile for historically monomorphic calls") \ 996 \ 997 product(bool, PrintInlining, false, DIAGNOSTIC, \ 998 "Print inlining optimizations") \ 999 \ 1000 product(bool, UsePopCountInstruction, false, \ 1001 "Use population count instruction") \ 1002 \ 1003 develop(bool, TraceMethodReplacement, false, \ 1004 "Print when methods are replaced do to recompilation") \ 1005 \ 1006 product(bool, PrintMethodFlushingStatistics, false, DIAGNOSTIC, \ 1007 "print statistics about method flushing") \ 1008 \ 1009 product(intx, MinPassesBeforeFlush, 10, DIAGNOSTIC, \ 1010 "Minimum number of sweeper passes before an nmethod " \ 1011 "can be flushed") \ 1012 range(0, max_intx) \ 1013 \ 1014 develop(bool, StressCodeBuffers, false, \ 1015 "Exercise code buffer expansion and other rare state changes") \ 1016 \ 1017 product(bool, DebugNonSafepoints, trueInDebug, DIAGNOSTIC, \ 1018 "Generate extra debugging information for non-safepoints in " \ 1019 "nmethods") \ 1020 \ 1021 product(bool, PrintVMOptions, false, \ 1022 "Print flags that appeared on the command line") \ 1023 \ 1024 product(bool, IgnoreUnrecognizedVMOptions, false, \ 1025 "Ignore unrecognized VM options") \ 1026 \ 1027 product(bool, PrintCommandLineFlags, false, \ 1028 "Print flags specified on command line or set by ergonomics") \ 1029 \ 1030 product(bool, PrintFlagsInitial, false, \ 1031 "Print all VM flags before argument processing and exit VM") \ 1032 \ 1033 product(bool, PrintFlagsFinal, false, \ 1034 "Print all VM flags after argument and ergonomic processing") \ 1035 \ 1036 notproduct(bool, PrintFlagsWithComments, false, \ 1037 "Print all VM flags with default values and descriptions and " \ 1038 "exit") \ 1039 \ 1040 product(bool, PrintFlagsRanges, false, \ 1041 "Print VM flags and their ranges") \ 1042 \ 1043 product(bool, SerializeVMOutput, true, DIAGNOSTIC, \ 1044 "Use a mutex to serialize output to tty and LogFile") \ 1045 \ 1046 product(bool, DisplayVMOutput, true, DIAGNOSTIC, \ 1047 "Display all VM output on the tty, independently of LogVMOutput") \ 1048 \ 1049 product(bool, LogVMOutput, false, DIAGNOSTIC, \ 1050 "Save VM output to LogFile") \ 1051 \ 1052 product(ccstr, LogFile, nullptr, DIAGNOSTIC, \ 1053 "If LogVMOutput or LogCompilation is on, save VM output to " \ 1054 "this file [default: ./hotspot_pid%p.log] (%p replaced with pid)")\ 1055 \ 1056 product(ccstr, ErrorFile, nullptr, \ 1057 "If an error occurs, save the error data to this file " \ 1058 "[default: ./hs_err_pid%p.log] (%p replaced with pid)") \ 1059 \ 1060 product(bool, ExtensiveErrorReports, \ 1061 PRODUCT_ONLY(false) NOT_PRODUCT(true), \ 1062 "Error reports are more extensive.") \ 1063 \ 1064 product(bool, DisplayVMOutputToStderr, false, \ 1065 "If DisplayVMOutput is true, display all VM output to stderr") \ 1066 \ 1067 product(bool, DisplayVMOutputToStdout, false, \ 1068 "If DisplayVMOutput is true, display all VM output to stdout") \ 1069 \ 1070 product(bool, ErrorFileToStderr, false, \ 1071 "If true, error data is printed to stderr instead of a file") \ 1072 \ 1073 product(bool, ErrorFileToStdout, false, \ 1074 "If true, error data is printed to stdout instead of a file") \ 1075 \ 1076 develop(bool, UseHeavyMonitors, false, \ 1077 "(Deprecated) Use heavyweight instead of lightweight Java " \ 1078 "monitors") \ 1079 \ 1080 develop(bool, VerifyHeavyMonitors, false, \ 1081 "Checks that no stack locking happens when using " \ 1082 "+UseHeavyMonitors") \ 1083 \ 1084 product(bool, PrintStringTableStatistics, false, \ 1085 "print statistics about the StringTable and SymbolTable") \ 1086 \ 1087 product(bool, VerifyStringTableAtExit, false, DIAGNOSTIC, \ 1088 "verify StringTable contents at exit") \ 1089 \ 1090 notproduct(bool, PrintSymbolTableSizeHistogram, false, \ 1091 "print histogram of the symbol table") \ 1092 \ 1093 product(ccstr, AbortVMOnException, nullptr, DIAGNOSTIC, \ 1094 "Call fatal if this exception is thrown. Example: " \ 1095 "java -XX:AbortVMOnException=java.lang.NullPointerException Foo") \ 1096 \ 1097 product(ccstr, AbortVMOnExceptionMessage, nullptr, DIAGNOSTIC, \ 1098 "Call fatal if the exception pointed by AbortVMOnException " \ 1099 "has this message") \ 1100 \ 1101 develop(bool, DebugVtables, false, \ 1102 "add debugging code to vtable dispatch") \ 1103 \ 1104 product(bool, RangeCheckElimination, true, \ 1105 "Eliminate range checks") \ 1106 \ 1107 develop_pd(bool, UncommonNullCast, \ 1108 "track occurrences of null in casts; adjust compiler tactics") \ 1109 \ 1110 develop(bool, TypeProfileCasts, true, \ 1111 "treat casts like calls for purposes of type profiling") \ 1112 \ 1113 develop(bool, TraceLivenessGen, false, \ 1114 "Trace the generation of liveness analysis information") \ 1115 \ 1116 notproduct(bool, TraceLivenessQuery, false, \ 1117 "Trace queries of liveness analysis information") \ 1118 \ 1119 notproduct(bool, CollectIndexSetStatistics, false, \ 1120 "Collect information about IndexSets") \ 1121 \ 1122 develop(intx, FastAllocateSizeLimit, 128*K, \ 1123 /* Note: This value is zero mod 1<<13 for a cheap sparc set. */ \ 1124 "Inline allocations larger than this in doublewords must go slow")\ 1125 \ 1126 product_pd(bool, CompactStrings, \ 1127 "Enable Strings to use single byte chars in backing store") \ 1128 \ 1129 product_pd(uint, TypeProfileLevel, \ 1130 "=XYZ, with Z: Type profiling of arguments at call; " \ 1131 "Y: Type profiling of return value at call; " \ 1132 "X: Type profiling of parameters to methods; " \ 1133 "X, Y and Z in 0=off ; 1=jsr292 only; 2=all methods") \ 1134 constraint(TypeProfileLevelConstraintFunc, AfterErgo) \ 1135 \ 1136 product(int, TypeProfileArgsLimit, 2, \ 1137 "max number of call arguments to consider for type profiling") \ 1138 range(0, 16) \ 1139 \ 1140 product(int, TypeProfileParmsLimit, 2, \ 1141 "max number of incoming parameters to consider for type profiling"\ 1142 ", -1 for all") \ 1143 range(-1, 64) \ 1144 \ 1145 /* statistics */ \ 1146 develop(bool, CountCompiledCalls, false, \ 1147 "Count method invocations") \ 1148 \ 1149 notproduct(bool, ICMissHistogram, false, \ 1150 "Produce histogram of IC misses") \ 1151 \ 1152 /* interpreter */ \ 1153 product_pd(bool, RewriteBytecodes, \ 1154 "Allow rewriting of bytecodes (bytecodes are not immutable)") \ 1155 \ 1156 product_pd(bool, RewriteFrequentPairs, \ 1157 "Rewrite frequently used bytecode pairs into a single bytecode") \ 1158 \ 1159 product(bool, PrintInterpreter, false, DIAGNOSTIC, \ 1160 "Print the generated interpreter code") \ 1161 \ 1162 product(bool, UseInterpreter, true, \ 1163 "Use interpreter for non-compiled methods") \ 1164 \ 1165 develop(bool, UseFastSignatureHandlers, true, \ 1166 "Use fast signature handlers for native calls") \ 1167 \ 1168 product(bool, UseLoopCounter, true, \ 1169 "Increment invocation counter on backward branch") \ 1170 \ 1171 product_pd(bool, UseOnStackReplacement, \ 1172 "Use on stack replacement, calls runtime if invoc. counter " \ 1173 "overflows in loop") \ 1174 \ 1175 notproduct(bool, TraceOnStackReplacement, false, \ 1176 "Trace on stack replacement") \ 1177 \ 1178 product_pd(bool, PreferInterpreterNativeStubs, \ 1179 "Use always interpreter stubs for native methods invoked via " \ 1180 "interpreter") \ 1181 \ 1182 develop(bool, CountBytecodes, false, \ 1183 "Count number of bytecodes executed") \ 1184 \ 1185 develop(bool, PrintBytecodeHistogram, false, \ 1186 "Print histogram of the executed bytecodes") \ 1187 \ 1188 develop(bool, PrintBytecodePairHistogram, false, \ 1189 "Print histogram of the executed bytecode pairs") \ 1190 \ 1191 product(bool, PrintSignatureHandlers, false, DIAGNOSTIC, \ 1192 "Print code generated for native method signature handlers") \ 1193 \ 1194 develop(bool, VerifyOops, false, \ 1195 "Do plausibility checks for oops") \ 1196 \ 1197 develop(bool, CheckUnhandledOops, false, \ 1198 "Check for unhandled oops in VM code") \ 1199 \ 1200 develop(bool, VerifyJNIFields, trueInDebug, \ 1201 "Verify jfieldIDs for instance fields") \ 1202 \ 1203 develop(bool, VerifyFPU, false, \ 1204 "Verify FPU state (check for NaN's, etc.)") \ 1205 \ 1206 develop(bool, VerifyActivationFrameSize, false, \ 1207 "Verify that activation frame didn't become smaller than its " \ 1208 "minimal size") \ 1209 \ 1210 develop(bool, TraceFrequencyInlining, false, \ 1211 "Trace frequency based inlining") \ 1212 \ 1213 develop_pd(bool, InlineIntrinsics, \ 1214 "Use intrinsics in Interpreter that can be statically resolved") \ 1215 \ 1216 product_pd(bool, ProfileInterpreter, \ 1217 "Profile at the bytecode level during interpretation") \ 1218 \ 1219 develop_pd(bool, ProfileTraps, \ 1220 "Profile deoptimization traps at the bytecode level") \ 1221 \ 1222 product(intx, ProfileMaturityPercentage, 20, \ 1223 "number of method invocations/branches (expressed as % of " \ 1224 "CompileThreshold) before using the method's profile") \ 1225 range(0, 100) \ 1226 \ 1227 product(bool, PrintMethodData, false, DIAGNOSTIC, \ 1228 "Print the results of +ProfileInterpreter at end of run") \ 1229 \ 1230 develop(bool, VerifyDataPointer, trueInDebug, \ 1231 "Verify the method data pointer during interpreter profiling") \ 1232 \ 1233 notproduct(bool, CrashGCForDumpingJavaThread, false, \ 1234 "Manually make GC thread crash then dump java stack trace; " \ 1235 "Test only") \ 1236 \ 1237 /* compilation */ \ 1238 product(bool, UseCompiler, true, \ 1239 "Use Just-In-Time compilation") \ 1240 \ 1241 product(bool, UseCounterDecay, true, \ 1242 "Adjust recompilation counters") \ 1243 \ 1244 develop(intx, CounterHalfLifeTime, 30, \ 1245 "Half-life time of invocation counters (in seconds)") \ 1246 \ 1247 develop(intx, CounterDecayMinIntervalLength, 500, \ 1248 "The minimum interval (in milliseconds) between invocation of " \ 1249 "CounterDecay") \ 1250 \ 1251 product(bool, AlwaysCompileLoopMethods, false, \ 1252 "When using recompilation, never interpret methods " \ 1253 "containing loops") \ 1254 \ 1255 product(intx, AllocatePrefetchStyle, 1, \ 1256 "0 = no prefetch, " \ 1257 "1 = generate prefetch instructions for each allocation, " \ 1258 "2 = use TLAB watermark to gate allocation prefetch, " \ 1259 "3 = generate one prefetch instruction per cache line") \ 1260 range(0, 3) \ 1261 \ 1262 product(intx, AllocatePrefetchDistance, -1, \ 1263 "Distance to prefetch ahead of allocation pointer. " \ 1264 "-1: use system-specific value (automatically determined") \ 1265 range(-1, 512) \ 1266 \ 1267 product(intx, AllocatePrefetchLines, 3, \ 1268 "Number of lines to prefetch ahead of array allocation pointer") \ 1269 range(1, 64) \ 1270 \ 1271 product(intx, AllocateInstancePrefetchLines, 1, \ 1272 "Number of lines to prefetch ahead of instance allocation " \ 1273 "pointer") \ 1274 range(1, 64) \ 1275 \ 1276 product(intx, AllocatePrefetchStepSize, 16, \ 1277 "Step size in bytes of sequential prefetch instructions") \ 1278 range(1, 512) \ 1279 constraint(AllocatePrefetchStepSizeConstraintFunc,AfterMemoryInit)\ 1280 \ 1281 product(intx, AllocatePrefetchInstr, 0, \ 1282 "Select instruction to prefetch ahead of allocation pointer") \ 1283 constraint(AllocatePrefetchInstrConstraintFunc, AfterMemoryInit) \ 1284 \ 1285 /* deoptimization */ \ 1286 product(bool, TraceDeoptimization, false, DIAGNOSTIC, \ 1287 "Trace deoptimization") \ 1288 \ 1289 develop(bool, PrintDeoptimizationDetails, false, \ 1290 "Print more information about deoptimization") \ 1291 \ 1292 develop(bool, DebugDeoptimization, false, \ 1293 "Tracing various information while debugging deoptimization") \ 1294 \ 1295 product(double, SelfDestructTimer, 0.0, \ 1296 "Will cause VM to terminate after a given time " \ 1297 "(in fractional minutes) " \ 1298 "(0.0 means off)") \ 1299 range(0.0, (double)max_intx) \ 1300 \ 1301 product(int, MaxJavaStackTraceDepth, 1024, \ 1302 "The maximum number of lines in the stack trace for Java " \ 1303 "exceptions (0 means all)") \ 1304 range(0, max_jint/2) \ 1305 \ 1306 /* notice: the max range value here is max_jint, not max_intx */ \ 1307 /* because of overflow issue */ \ 1308 product(intx, GuaranteedSafepointInterval, 1000, DIAGNOSTIC, \ 1309 "Guarantee a safepoint (at least) every so many milliseconds " \ 1310 "(0 means none)") \ 1311 range(0, max_jint) \ 1312 \ 1313 product(double, SafepointTimeoutDelay, 10000, \ 1314 "Delay in milliseconds for option SafepointTimeout; " \ 1315 "supports sub-millisecond resolution with fractional values.") \ 1316 range(0, max_jlongDouble LP64_ONLY(/MICROUNITS)) \ 1317 \ 1318 product(bool, UseSystemMemoryBarrier, false, \ 1319 "Try to enable system memory barrier if supported by OS") \ 1320 \ 1321 product(intx, NmethodSweepActivity, 4, \ 1322 "Removes cold nmethods from code cache if > 0. Higher values " \ 1323 "result in more aggressive sweeping") \ 1324 range(0, 2000) \ 1325 \ 1326 develop(intx, MallocCatchPtr, -1, \ 1327 "Hit breakpoint when mallocing/freeing this pointer") \ 1328 \ 1329 develop(intx, StackPrintLimit, 100, \ 1330 "number of stack frames to print in VM-level stack dump") \ 1331 \ 1332 product(int, ErrorLogPrintCodeLimit, 3, DIAGNOSTIC, \ 1333 "max number of compiled code units to print in error log") \ 1334 range(0, VMError::max_error_log_print_code) \ 1335 \ 1336 notproduct(intx, MaxElementPrintSize, 256, \ 1337 "maximum number of elements to print") \ 1338 \ 1339 notproduct(intx, MaxSubklassPrintSize, 4, \ 1340 "maximum number of subklasses to print when printing klass") \ 1341 \ 1342 develop(intx, MaxForceInlineLevel, 100, \ 1343 "maximum number of nested calls that are forced for inlining " \ 1344 "(using CompileCommand or marked w/ @ForceInline)") \ 1345 range(0, max_jint) \ 1346 \ 1347 develop(intx, MethodHistogramCutoff, 100, \ 1348 "The cutoff value for method invocation histogram (+CountCalls)") \ 1349 \ 1350 develop(intx, DontYieldALotInterval, 10, \ 1351 "Interval between which yields will be dropped (milliseconds)") \ 1352 \ 1353 notproduct(intx, DeoptimizeALotInterval, 5, \ 1354 "Number of exits until DeoptimizeALot kicks in") \ 1355 \ 1356 notproduct(intx, ZombieALotInterval, 5, \ 1357 "Number of exits until ZombieALot kicks in") \ 1358 \ 1359 product(ccstr, MallocLimit, nullptr, DIAGNOSTIC, \ 1360 "Limit malloc allocation size from VM. Reaching a limit will " \ 1361 "trigger an action (see flag). This feature requires " \ 1362 "NativeMemoryTracking=summary or NativeMemoryTracking=detail." \ 1363 "Usage:" \ 1364 "\"-XX:MallocLimit=<size>[:<flag>]\" sets a total limit." \ 1365 "\"-XX:MallocLimit=<category>:<size>[:<flag>][,<category>:<size>[:<flag>] ...]\"" \ 1366 "sets one or more category-specific limits." \ 1367 "<flag> defines the action upon reaching the limit:" \ 1368 "\"fatal\": end VM with a fatal error at the allocation site" \ 1369 "\"oom\" : will mimic a native OOM" \ 1370 "If <flag> is omitted, \"fatal\" is the default." \ 1371 "Examples:\n" \ 1372 "-XX:MallocLimit=2g" \ 1373 "-XX:MallocLimit=2g:oom" \ 1374 "-XX:MallocLimit=compiler:200m:oom,code:100m") \ 1375 \ 1376 product(intx, TypeProfileWidth, 2, \ 1377 "Number of receiver types to record in call/cast profile") \ 1378 range(0, 8) \ 1379 \ 1380 develop(intx, BciProfileWidth, 2, \ 1381 "Number of return bci's to record in ret profile") \ 1382 \ 1383 product(intx, PerMethodRecompilationCutoff, 400, \ 1384 "After recompiling N times, stay in the interpreter (-1=>'Inf')") \ 1385 range(-1, max_intx) \ 1386 \ 1387 product(intx, PerBytecodeRecompilationCutoff, 200, \ 1388 "Per-BCI limit on repeated recompilation (-1=>'Inf')") \ 1389 range(-1, max_intx) \ 1390 \ 1391 product(intx, PerMethodTrapLimit, 100, \ 1392 "Limit on traps (of one kind) in a method (includes inlines)") \ 1393 range(0, max_jint) \ 1394 \ 1395 product(intx, PerMethodSpecTrapLimit, 5000, EXPERIMENTAL, \ 1396 "Limit on speculative traps (of one kind) in a method " \ 1397 "(includes inlines)") \ 1398 range(0, max_jint) \ 1399 \ 1400 product(intx, PerBytecodeTrapLimit, 4, \ 1401 "Limit on traps (of one kind) at a particular BCI") \ 1402 range(0, max_jint) \ 1403 \ 1404 product(int, SpecTrapLimitExtraEntries, 3, EXPERIMENTAL, \ 1405 "Extra method data trap entries for speculation") \ 1406 \ 1407 product(double, InlineFrequencyRatio, 0.25, DIAGNOSTIC, \ 1408 "Ratio of call site execution to caller method invocation") \ 1409 \ 1410 product(double, MinInlineFrequencyRatio, 0.0085, DIAGNOSTIC, \ 1411 "Minimum ratio of call site execution to caller method" \ 1412 "invocation to be considered for inlining") \ 1413 \ 1414 develop(intx, InlineThrowCount, 50, \ 1415 "Force inlining of interpreted methods that throw this often") \ 1416 range(0, max_jint) \ 1417 \ 1418 develop(intx, InlineThrowMaxSize, 200, \ 1419 "Force inlining of throwing methods smaller than this") \ 1420 range(0, max_jint) \ 1421 \ 1422 product(size_t, MetaspaceSize, NOT_LP64(16 * M) LP64_ONLY(21 * M), \ 1423 "Initial threshold (in bytes) at which a garbage collection " \ 1424 "is done to reduce Metaspace usage") \ 1425 constraint(MetaspaceSizeConstraintFunc,AfterErgo) \ 1426 \ 1427 product(size_t, MaxMetaspaceSize, max_uintx, \ 1428 "Maximum size of Metaspaces (in bytes)") \ 1429 constraint(MaxMetaspaceSizeConstraintFunc,AfterErgo) \ 1430 \ 1431 product(size_t, CompressedClassSpaceSize, 1*G, \ 1432 "Maximum size of class area in Metaspace when compressed " \ 1433 "class pointers are used") \ 1434 range(1*M, 3*G) \ 1435 \ 1436 develop(size_t, CompressedClassSpaceBaseAddress, 0, \ 1437 "Force the class space to be allocated at this address or " \ 1438 "fails VM initialization (requires -Xshare=off.") \ 1439 \ 1440 product(bool, PrintMetaspaceStatisticsAtExit, false, DIAGNOSTIC, \ 1441 "Print metaspace statistics upon VM exit.") \ 1442 \ 1443 develop(bool, MetaspaceGuardAllocations, false, \ 1444 "Metapace allocations are guarded.") \ 1445 \ 1446 product(uintx, MinHeapFreeRatio, 40, MANAGEABLE, \ 1447 "The minimum percentage of heap free after GC to avoid expansion."\ 1448 " For most GCs this applies to the old generation. In G1 and" \ 1449 " ParallelGC it applies to the whole heap.") \ 1450 range(0, 100) \ 1451 constraint(MinHeapFreeRatioConstraintFunc,AfterErgo) \ 1452 \ 1453 product(uintx, MaxHeapFreeRatio, 70, MANAGEABLE, \ 1454 "The maximum percentage of heap free after GC to avoid shrinking."\ 1455 " For most GCs this applies to the old generation. In G1 and" \ 1456 " ParallelGC it applies to the whole heap.") \ 1457 range(0, 100) \ 1458 constraint(MaxHeapFreeRatioConstraintFunc,AfterErgo) \ 1459 \ 1460 product(bool, ShrinkHeapInSteps, true, \ 1461 "When disabled, informs the GC to shrink the java heap directly" \ 1462 " to the target size at the next full GC rather than requiring" \ 1463 " smaller steps during multiple full GCs.") \ 1464 \ 1465 product(intx, SoftRefLRUPolicyMSPerMB, 1000, \ 1466 "Number of milliseconds per MB of free space in the heap") \ 1467 range(0, max_intx) \ 1468 constraint(SoftRefLRUPolicyMSPerMBConstraintFunc,AfterMemoryInit) \ 1469 \ 1470 product(size_t, MinHeapDeltaBytes, ScaleForWordSize(128*K), \ 1471 "The minimum change in heap space due to GC (in bytes)") \ 1472 range(0, max_uintx) \ 1473 \ 1474 product(size_t, MinMetaspaceExpansion, ScaleForWordSize(256*K), \ 1475 "The minimum expansion of Metaspace (in bytes)") \ 1476 range(0, max_uintx) \ 1477 \ 1478 product(uintx, MaxMetaspaceFreeRatio, 70, \ 1479 "The maximum percentage of Metaspace free after GC to avoid " \ 1480 "shrinking") \ 1481 range(0, 100) \ 1482 constraint(MaxMetaspaceFreeRatioConstraintFunc,AfterErgo) \ 1483 \ 1484 product(uintx, MinMetaspaceFreeRatio, 40, \ 1485 "The minimum percentage of Metaspace free after GC to avoid " \ 1486 "expansion") \ 1487 range(0, 99) \ 1488 constraint(MinMetaspaceFreeRatioConstraintFunc,AfterErgo) \ 1489 \ 1490 product(size_t, MaxMetaspaceExpansion, ScaleForWordSize(4*M), \ 1491 "The maximum expansion of Metaspace without full GC (in bytes)") \ 1492 range(0, max_uintx) \ 1493 \ 1494 /* stack parameters */ \ 1495 product_pd(intx, StackYellowPages, \ 1496 "Number of yellow zone (recoverable overflows) pages of size " \ 1497 "4KB. If pages are bigger yellow zone is aligned up.") \ 1498 range(MIN_STACK_YELLOW_PAGES, (DEFAULT_STACK_YELLOW_PAGES+5)) \ 1499 \ 1500 product_pd(intx, StackRedPages, \ 1501 "Number of red zone (unrecoverable overflows) pages of size " \ 1502 "4KB. If pages are bigger red zone is aligned up.") \ 1503 range(MIN_STACK_RED_PAGES, (DEFAULT_STACK_RED_PAGES+2)) \ 1504 \ 1505 product_pd(intx, StackReservedPages, \ 1506 "Number of reserved zone (reserved to annotated methods) pages" \ 1507 " of size 4KB. If pages are bigger reserved zone is aligned up.") \ 1508 range(MIN_STACK_RESERVED_PAGES, (DEFAULT_STACK_RESERVED_PAGES+10))\ 1509 \ 1510 product(bool, RestrictReservedStack, true, \ 1511 "Restrict @ReservedStackAccess to trusted classes") \ 1512 \ 1513 /* greater stack shadow pages can't generate instruction to bang stack */ \ 1514 product_pd(intx, StackShadowPages, \ 1515 "Number of shadow zone (for overflow checking) pages of size " \ 1516 "4KB. If pages are bigger shadow zone is aligned up. " \ 1517 "This should exceed the depth of the VM and native call stack.") \ 1518 range(MIN_STACK_SHADOW_PAGES, (DEFAULT_STACK_SHADOW_PAGES+30)) \ 1519 \ 1520 product_pd(intx, ThreadStackSize, \ 1521 "Thread Stack Size (in Kbytes)") \ 1522 range(0, 1 * M) \ 1523 \ 1524 product_pd(intx, VMThreadStackSize, \ 1525 "Non-Java Thread Stack Size (in Kbytes)") \ 1526 range(0, max_intx/(1 * K)) \ 1527 \ 1528 product_pd(intx, CompilerThreadStackSize, \ 1529 "Compiler Thread Stack Size (in Kbytes)") \ 1530 range(0, max_intx/(1 * K)) \ 1531 \ 1532 develop_pd(size_t, JVMInvokeMethodSlack, \ 1533 "Stack space (bytes) required for JVM_InvokeMethod to complete") \ 1534 \ 1535 /* code cache parameters */ \ 1536 product_pd(uintx, CodeCacheSegmentSize, EXPERIMENTAL, \ 1537 "Code cache segment size (in bytes) - smallest unit of " \ 1538 "allocation") \ 1539 range(1, 1024) \ 1540 constraint(CodeCacheSegmentSizeConstraintFunc, AfterErgo) \ 1541 \ 1542 product_pd(intx, CodeEntryAlignment, EXPERIMENTAL, \ 1543 "Code entry alignment for generated code (in bytes)") \ 1544 constraint(CodeEntryAlignmentConstraintFunc, AfterErgo) \ 1545 \ 1546 product_pd(intx, OptoLoopAlignment, \ 1547 "Align inner loops to zero relative to this modulus") \ 1548 range(1, 128) \ 1549 constraint(OptoLoopAlignmentConstraintFunc, AfterErgo) \ 1550 \ 1551 product_pd(uintx, InitialCodeCacheSize, \ 1552 "Initial code cache size (in bytes)") \ 1553 constraint(VMPageSizeConstraintFunc, AtParse) \ 1554 \ 1555 develop_pd(uintx, CodeCacheMinimumUseSpace, \ 1556 "Minimum code cache size (in bytes) required to start VM.") \ 1557 range(0, max_uintx) \ 1558 \ 1559 product(bool, SegmentedCodeCache, false, \ 1560 "Use a segmented code cache") \ 1561 \ 1562 product_pd(uintx, ReservedCodeCacheSize, \ 1563 "Reserved code cache size (in bytes) - maximum code cache size") \ 1564 constraint(VMPageSizeConstraintFunc, AtParse) \ 1565 \ 1566 product_pd(uintx, NonProfiledCodeHeapSize, \ 1567 "Size of code heap with non-profiled methods (in bytes)") \ 1568 range(0, max_uintx) \ 1569 \ 1570 product_pd(uintx, ProfiledCodeHeapSize, \ 1571 "Size of code heap with profiled methods (in bytes)") \ 1572 range(0, max_uintx) \ 1573 \ 1574 product_pd(uintx, NonNMethodCodeHeapSize, \ 1575 "Size of code heap with non-nmethods (in bytes)") \ 1576 constraint(VMPageSizeConstraintFunc, AtParse) \ 1577 \ 1578 product_pd(uintx, CodeCacheExpansionSize, \ 1579 "Code cache expansion size (in bytes)") \ 1580 range(32*K, max_uintx) \ 1581 \ 1582 product_pd(uintx, CodeCacheMinBlockLength, DIAGNOSTIC, \ 1583 "Minimum number of segments in a code cache block") \ 1584 range(1, 100) \ 1585 \ 1586 notproduct(bool, ExitOnFullCodeCache, false, \ 1587 "Exit the VM if we fill the code cache") \ 1588 \ 1589 product(bool, UseCodeCacheFlushing, true, \ 1590 "Remove cold/old nmethods from the code cache") \ 1591 \ 1592 product(double, SweeperThreshold, 15.0, \ 1593 "Threshold when a code cache unloading GC is invoked." \ 1594 "Value is percentage of ReservedCodeCacheSize.") \ 1595 range(0.0, 100.0) \ 1596 \ 1597 product(uintx, StartAggressiveSweepingAt, 10, \ 1598 "Start aggressive sweeping if X[%] of the code cache is free." \ 1599 "Segmented code cache: X[%] of the non-profiled heap." \ 1600 "Non-segmented code cache: X[%] of the total code cache") \ 1601 range(0, 100) \ 1602 \ 1603 /* interpreter debugging */ \ 1604 develop(intx, BinarySwitchThreshold, 5, \ 1605 "Minimal number of lookupswitch entries for rewriting to binary " \ 1606 "switch") \ 1607 \ 1608 develop(intx, StopInterpreterAt, 0, \ 1609 "Stop interpreter execution at specified bytecode number") \ 1610 \ 1611 develop(intx, TraceBytecodesAt, 0, \ 1612 "Trace bytecodes starting with specified bytecode number") \ 1613 \ 1614 develop(intx, TraceBytecodesStopAt, 0, \ 1615 "Stop bytecode tracing at the specified bytecode number") \ 1616 \ 1617 /* Priorities */ \ 1618 product_pd(bool, UseThreadPriorities, "Use native thread priorities") \ 1619 \ 1620 product(int, ThreadPriorityPolicy, 0, \ 1621 "0 : Normal. "\ 1622 " VM chooses priorities that are appropriate for normal "\ 1623 " applications. "\ 1624 " On Windows applications are allowed to use higher native "\ 1625 " priorities. However, with ThreadPriorityPolicy=0, VM will "\ 1626 " not use the highest possible native priority, "\ 1627 " THREAD_PRIORITY_TIME_CRITICAL, as it may interfere with "\ 1628 " system threads. On Linux thread priorities are ignored "\ 1629 " because the OS does not support static priority in "\ 1630 " SCHED_OTHER scheduling class which is the only choice for "\ 1631 " non-root, non-realtime applications. "\ 1632 "1 : Aggressive. "\ 1633 " Java thread priorities map over to the entire range of "\ 1634 " native thread priorities. Higher Java thread priorities map "\ 1635 " to higher native thread priorities. This policy should be "\ 1636 " used with care, as sometimes it can cause performance "\ 1637 " degradation in the application and/or the entire system. On "\ 1638 " Linux/BSD/macOS this policy requires root privilege or an "\ 1639 " extended capability.") \ 1640 range(0, 1) \ 1641 \ 1642 product(bool, ThreadPriorityVerbose, false, \ 1643 "Print priority changes") \ 1644 \ 1645 product(int, CompilerThreadPriority, -1, \ 1646 "The native priority at which compiler threads should run " \ 1647 "(-1 means no change)") \ 1648 range(min_jint, max_jint) \ 1649 \ 1650 product(int, VMThreadPriority, -1, \ 1651 "The native priority at which the VM thread should run " \ 1652 "(-1 means no change)") \ 1653 range(-1, 127) \ 1654 \ 1655 product(int, JavaPriority1_To_OSPriority, -1, \ 1656 "Map Java priorities to OS priorities") \ 1657 range(-1, 127) \ 1658 \ 1659 product(int, JavaPriority2_To_OSPriority, -1, \ 1660 "Map Java priorities to OS priorities") \ 1661 range(-1, 127) \ 1662 \ 1663 product(int, JavaPriority3_To_OSPriority, -1, \ 1664 "Map Java priorities to OS priorities") \ 1665 range(-1, 127) \ 1666 \ 1667 product(int, JavaPriority4_To_OSPriority, -1, \ 1668 "Map Java priorities to OS priorities") \ 1669 range(-1, 127) \ 1670 \ 1671 product(int, JavaPriority5_To_OSPriority, -1, \ 1672 "Map Java priorities to OS priorities") \ 1673 range(-1, 127) \ 1674 \ 1675 product(int, JavaPriority6_To_OSPriority, -1, \ 1676 "Map Java priorities to OS priorities") \ 1677 range(-1, 127) \ 1678 \ 1679 product(int, JavaPriority7_To_OSPriority, -1, \ 1680 "Map Java priorities to OS priorities") \ 1681 range(-1, 127) \ 1682 \ 1683 product(int, JavaPriority8_To_OSPriority, -1, \ 1684 "Map Java priorities to OS priorities") \ 1685 range(-1, 127) \ 1686 \ 1687 product(int, JavaPriority9_To_OSPriority, -1, \ 1688 "Map Java priorities to OS priorities") \ 1689 range(-1, 127) \ 1690 \ 1691 product(int, JavaPriority10_To_OSPriority,-1, \ 1692 "Map Java priorities to OS priorities") \ 1693 range(-1, 127) \ 1694 \ 1695 product(bool, UseCriticalJavaThreadPriority, false, EXPERIMENTAL, \ 1696 "Java thread priority 10 maps to critical scheduling priority") \ 1697 \ 1698 product(bool, UseCriticalCompilerThreadPriority, false, EXPERIMENTAL, \ 1699 "Compiler thread(s) run at critical scheduling priority") \ 1700 \ 1701 develop(intx, NewCodeParameter, 0, \ 1702 "Testing Only: Create a dedicated integer parameter before " \ 1703 "putback") \ 1704 \ 1705 /* new oopmap storage allocation */ \ 1706 develop(intx, MinOopMapAllocation, 8, \ 1707 "Minimum number of OopMap entries in an OopMapSet") \ 1708 \ 1709 /* recompilation */ \ 1710 product_pd(intx, CompileThreshold, \ 1711 "number of interpreted method invocations before (re-)compiling") \ 1712 constraint(CompileThresholdConstraintFunc, AfterErgo) \ 1713 \ 1714 product_pd(bool, TieredCompilation, \ 1715 "Enable tiered compilation") \ 1716 \ 1717 /* Properties for Java libraries */ \ 1718 \ 1719 product(uint64_t, MaxDirectMemorySize, 0, \ 1720 "Maximum total size of NIO direct-buffer allocations. " \ 1721 "Ignored if not explicitly set.") \ 1722 range(0, max_jlong) \ 1723 \ 1724 /* Flags used for temporary code during development */ \ 1725 \ 1726 product(bool, UseNewCode, false, DIAGNOSTIC, \ 1727 "Testing Only: Use the new version while testing") \ 1728 \ 1729 product(bool, UseNewCode2, false, DIAGNOSTIC, \ 1730 "Testing Only: Use the new version while testing") \ 1731 \ 1732 product(bool, UseNewCode3, false, DIAGNOSTIC, \ 1733 "Testing Only: Use the new version while testing") \ 1734 \ 1735 notproduct(bool, UseDebuggerErgo, false, \ 1736 "Debugging Only: Adjust the VM to be more debugger-friendly. " \ 1737 "Turns on the other UseDebuggerErgo* flags") \ 1738 \ 1739 notproduct(bool, UseDebuggerErgo1, false, \ 1740 "Debugging Only: Enable workarounds for debugger induced " \ 1741 "os::processor_id() >= os::processor_count() problems") \ 1742 \ 1743 notproduct(bool, UseDebuggerErgo2, false, \ 1744 "Debugging Only: Limit the number of spawned JVM threads") \ 1745 \ 1746 notproduct(bool, EnableJVMTIStackDepthAsserts, true, \ 1747 "Enable JVMTI asserts related to stack depth checks") \ 1748 \ 1749 /* flags for performance data collection */ \ 1750 \ 1751 product(bool, UsePerfData, true, \ 1752 "Flag to disable jvmstat instrumentation for performance testing "\ 1753 "and problem isolation purposes") \ 1754 \ 1755 product(bool, PerfDataSaveToFile, false, \ 1756 "Save PerfData memory to hsperfdata_<pid> file on exit") \ 1757 \ 1758 product(ccstr, PerfDataSaveFile, nullptr, \ 1759 "Save PerfData memory to the specified absolute pathname. " \ 1760 "The string %p in the file name (if present) " \ 1761 "will be replaced by pid") \ 1762 \ 1763 product(intx, PerfDataSamplingInterval, 50, \ 1764 "Data sampling interval (in milliseconds)") \ 1765 range(PeriodicTask::min_interval, max_jint) \ 1766 constraint(PerfDataSamplingIntervalFunc, AfterErgo) \ 1767 \ 1768 product(bool, PerfDisableSharedMem, false, \ 1769 "Store performance data in standard memory") \ 1770 \ 1771 product(int, PerfDataMemorySize, 32*K, \ 1772 "Size of performance data memory region. Will be rounded " \ 1773 "up to a multiple of the native os page size.") \ 1774 range(128, 32*64*K) \ 1775 \ 1776 product(int, PerfMaxStringConstLength, 1024, \ 1777 "Maximum PerfStringConstant string length before truncation") \ 1778 range(32, 32*K) \ 1779 \ 1780 product(bool, PerfAllowAtExitRegistration, false, \ 1781 "Allow registration of atexit() methods") \ 1782 \ 1783 product(bool, PerfBypassFileSystemCheck, false, \ 1784 "Bypass Win32 file system criteria checks (Windows Only)") \ 1785 \ 1786 product(int, UnguardOnExecutionViolation, 0, \ 1787 "Unguard page and retry on no-execute fault (Win32 only) " \ 1788 "0=off, 1=conservative, 2=aggressive") \ 1789 range(0, 2) \ 1790 \ 1791 /* Serviceability Support */ \ 1792 \ 1793 product(bool, ManagementServer, false, \ 1794 "Create JMX Management Server") \ 1795 \ 1796 product(bool, DisableAttachMechanism, false, \ 1797 "Disable mechanism that allows tools to attach to this VM") \ 1798 \ 1799 product(bool, StartAttachListener, false, \ 1800 "Always start Attach Listener at VM startup") \ 1801 \ 1802 product(bool, EnableDynamicAgentLoading, true, \ 1803 "Allow tools to load agents with the attach mechanism") \ 1804 \ 1805 product(bool, PrintConcurrentLocks, false, MANAGEABLE, \ 1806 "Print java.util.concurrent locks in thread dump") \ 1807 \ 1808 product(bool, PrintMethodHandleStubs, false, DIAGNOSTIC, \ 1809 "Print generated stub code for method handles") \ 1810 \ 1811 product(bool, VerifyMethodHandles, trueInDebug, DIAGNOSTIC, \ 1812 "perform extra checks when constructing method handles") \ 1813 \ 1814 product(bool, ShowHiddenFrames, false, DIAGNOSTIC, \ 1815 "show method handle implementation frames (usually hidden)") \ 1816 \ 1817 product(bool, ShowCarrierFrames, false, DIAGNOSTIC, \ 1818 "show virtual threads' carrier frames in exceptions") \ 1819 \ 1820 product(bool, TrustFinalNonStaticFields, false, EXPERIMENTAL, \ 1821 "trust final non-static declarations for constant folding") \ 1822 \ 1823 product(bool, FoldStableValues, true, DIAGNOSTIC, \ 1824 "Optimize loads from stable fields (marked w/ @Stable)") \ 1825 \ 1826 product(int, UseBootstrapCallInfo, 1, DIAGNOSTIC, \ 1827 "0: when resolving InDy or ConDy, force all BSM arguments to be " \ 1828 "resolved before the bootstrap method is called; 1: when a BSM " \ 1829 "that may accept a BootstrapCallInfo is detected, use that API " \ 1830 "to pass BSM arguments, which allows the BSM to delay their " \ 1831 "resolution; 2+: stress test the BCI API by calling more BSMs " \ 1832 "via that API, instead of with the eagerly-resolved array.") \ 1833 \ 1834 product(bool, PauseAtStartup, false, DIAGNOSTIC, \ 1835 "Causes the VM to pause at startup time and wait for the pause " \ 1836 "file to be removed (default: ./vm.paused.<pid>)") \ 1837 \ 1838 product(ccstr, PauseAtStartupFile, nullptr, DIAGNOSTIC, \ 1839 "The file to create and for whose removal to await when pausing " \ 1840 "at startup. (default: ./vm.paused.<pid>)") \ 1841 \ 1842 product(bool, PauseAtExit, false, DIAGNOSTIC, \ 1843 "Pause and wait for keypress on exit if a debugger is attached") \ 1844 \ 1845 product(bool, DTraceMethodProbes, false, \ 1846 "Enable dtrace tool probes for method-entry and method-exit") \ 1847 \ 1848 product(bool, DTraceAllocProbes, false, \ 1849 "Enable dtrace tool probes for object allocation") \ 1850 \ 1851 product(bool, DTraceMonitorProbes, false, \ 1852 "Enable dtrace tool probes for monitor events") \ 1853 \ 1854 product(bool, RelaxAccessControlCheck, false, \ 1855 "Relax the access control checks in the verifier") \ 1856 \ 1857 product(uintx, StringTableSize, defaultStringTableSize, \ 1858 "Number of buckets in the interned String table " \ 1859 "(will be rounded to nearest higher power of 2)") \ 1860 range(minimumStringTableSize, 16777216ul /* 2^24 */) \ 1861 \ 1862 product(uintx, SymbolTableSize, defaultSymbolTableSize, EXPERIMENTAL, \ 1863 "Number of buckets in the JVM internal Symbol table") \ 1864 range(minimumSymbolTableSize, 16777216ul /* 2^24 */) \ 1865 \ 1866 product(bool, UseStringDeduplication, false, \ 1867 "Use string deduplication") \ 1868 \ 1869 product(uint, StringDeduplicationAgeThreshold, 3, \ 1870 "A string must reach this age (or be promoted to an old region) " \ 1871 "to be considered for deduplication") \ 1872 range(1, markWord::max_age) \ 1873 \ 1874 product(size_t, StringDeduplicationInitialTableSize, 500, EXPERIMENTAL, \ 1875 "Approximate initial number of buckets in the table") \ 1876 range(1, 1 * G) \ 1877 \ 1878 product(double, StringDeduplicationGrowTableLoad, 14.0, EXPERIMENTAL, \ 1879 "Entries per bucket above which the table should be expanded") \ 1880 range(0.1, 1000.0) \ 1881 \ 1882 product(double, StringDeduplicationShrinkTableLoad, 1.0, EXPERIMENTAL, \ 1883 "Entries per bucket below which the table should be shrunk") \ 1884 range(0.01, 100.0) \ 1885 \ 1886 product(double, StringDeduplicationTargetTableLoad, 7.0, EXPERIMENTAL, \ 1887 "Desired entries per bucket when resizing the table") \ 1888 range(0.01, 1000.0) \ 1889 \ 1890 product(size_t, StringDeduplicationCleanupDeadMinimum, 100, EXPERIMENTAL, \ 1891 "Minimum number of dead table entries for cleaning the table") \ 1892 \ 1893 product(int, StringDeduplicationCleanupDeadPercent, 5, EXPERIMENTAL, \ 1894 "Minimum percentage of dead table entries for cleaning the table") \ 1895 range(1, 100) \ 1896 \ 1897 product(bool, StringDeduplicationResizeALot, false, DIAGNOSTIC, \ 1898 "Force more frequent table resizing") \ 1899 \ 1900 product(uint64_t, StringDeduplicationHashSeed, 0, DIAGNOSTIC, \ 1901 "Seed for the table hashing function; 0 requests computed seed") \ 1902 \ 1903 product(bool, WhiteBoxAPI, false, DIAGNOSTIC, \ 1904 "Enable internal testing APIs") \ 1905 \ 1906 product(size_t, ArrayAllocatorMallocLimit, SIZE_MAX, EXPERIMENTAL, \ 1907 "Allocation less than this value will be allocated " \ 1908 "using malloc. Larger allocations will use mmap.") \ 1909 \ 1910 product(bool, AlwaysAtomicAccesses, false, EXPERIMENTAL, \ 1911 "Accesses to all variables should always be atomic") \ 1912 \ 1913 product(bool, UseUnalignedAccesses, false, DIAGNOSTIC, \ 1914 "Use unaligned memory accesses in Unsafe") \ 1915 \ 1916 product_pd(bool, PreserveFramePointer, \ 1917 "Use the FP register for holding the frame pointer " \ 1918 "and not as a general purpose register.") \ 1919 \ 1920 product(size_t, AsyncLogBufferSize, 2*M, \ 1921 "Memory budget (in bytes) for the buffer of Asynchronous " \ 1922 "Logging (-Xlog:async).") \ 1923 range(100*K, 50*M) \ 1924 \ 1925 product(bool, CheckIntrinsics, true, DIAGNOSTIC, \ 1926 "When a class C is loaded, check that " \ 1927 "(1) all intrinsics defined by the VM for class C are present "\ 1928 "in the loaded class file and are marked with the " \ 1929 "@IntrinsicCandidate annotation, that " \ 1930 "(2) there is an intrinsic registered for all loaded methods " \ 1931 "that are annotated with the @IntrinsicCandidate annotation, " \ 1932 "and that " \ 1933 "(3) no orphan methods exist for class C (i.e., methods for " \ 1934 "which the VM declares an intrinsic but that are not declared "\ 1935 "in the loaded class C. " \ 1936 "Check (3) is available only in debug builds.") \ 1937 \ 1938 product_pd(intx, InitArrayShortSize, DIAGNOSTIC, \ 1939 "Threshold small size (in bytes) for clearing arrays. " \ 1940 "Anything this size or smaller may get converted to discrete " \ 1941 "scalar stores.") \ 1942 range(0, max_intx) \ 1943 constraint(InitArrayShortSizeConstraintFunc, AfterErgo) \ 1944 \ 1945 product(ccstr, AllocateHeapAt, nullptr, \ 1946 "Path to the directory where a temporary file will be created " \ 1947 "to use as the backing store for Java Heap.") \ 1948 \ 1949 product_pd(bool, VMContinuations, EXPERIMENTAL, \ 1950 "Enable VM continuations support") \ 1951 \ 1952 develop(bool, LoomDeoptAfterThaw, false, \ 1953 "Deopt stack after thaw") \ 1954 \ 1955 develop(bool, LoomVerifyAfterThaw, false, \ 1956 "Verify stack after thaw") \ 1957 \ 1958 develop(bool, VerifyContinuations, false, \ 1959 "Verify continuation consistency") \ 1960 \ 1961 develop(bool, UseContinuationFastPath, true, \ 1962 "Use fast-path frame walking in continuations") \ 1963 \ 1964 develop(int, VerifyMetaspaceInterval, DEBUG_ONLY(500) NOT_DEBUG(0), \ 1965 "Run periodic metaspace verifications (0 - none, " \ 1966 "1 - always, >1 every nth interval)") \ 1967 \ 1968 product(bool, ShowRegistersOnAssert, true, DIAGNOSTIC, \ 1969 "On internal errors, include registers in error report.") \ 1970 \ 1971 product(bool, UseSwitchProfiling, true, DIAGNOSTIC, \ 1972 "leverage profiling for table/lookup switch") \ 1973 \ 1974 develop(bool, TraceMemoryWriteback, false, \ 1975 "Trace memory writeback operations") \ 1976 \ 1977 JFR_ONLY(product(bool, FlightRecorder, false, \ 1978 "(Deprecated) Enable Flight Recorder")) \ 1979 \ 1980 JFR_ONLY(product(ccstr, FlightRecorderOptions, nullptr, \ 1981 "Flight Recorder options")) \ 1982 \ 1983 JFR_ONLY(product(ccstr, StartFlightRecording, nullptr, \ 1984 "Start flight recording with options")) \ 1985 \ 1986 product(bool, UseFastUnorderedTimeStamps, false, EXPERIMENTAL, \ 1987 "Use platform unstable time where supported for timestamps only") \ 1988 \ 1989 product(bool, EnableValhalla, true, \ 1990 "Enable experimental Valhalla features") \ 1991 \ 1992 product(bool, EnablePrimitiveClasses, false, \ 1993 "Enable experimental Valhalla primitive classes") \ 1994 \ 1995 product_pd(bool, InlineTypePassFieldsAsArgs, \ 1996 "Pass each inline type field as an argument at calls") \ 1997 \ 1998 product_pd(bool, InlineTypeReturnedAsFields, \ 1999 "Return fields instead of an inline type reference") \ 2000 \ 2001 develop(bool, StressCallingConvention, false, \ 2002 "Stress the scalarized calling convention.") \ 2003 \ 2004 product(bool, UseArrayMarkWordCheck, NOT_LP64(false) LP64_ONLY(true), \ 2005 "Use bits in the mark word to check for flat/null-free arrays") \ 2006 \ 2007 product(ccstrlist, ForceNonTearable, "", DIAGNOSTIC, \ 2008 "List of inline classes which are forced to be atomic " \ 2009 "(whitespace and commas separate names, " \ 2010 "and leading and trailing stars '*' are wildcards)") \ 2011 \ 2012 product(bool, UseEmptySlotsInSupers, true, \ 2013 "Allow allocating fields in empty slots of super-classes") \ 2014 \ 2015 product(bool, DeoptimizeNMethodBarriersALot, false, DIAGNOSTIC, \ 2016 "Make nmethod barriers deoptimise a lot.") \ 2017 \ 2018 develop(bool, VerifyCrossModifyFence, \ 2019 false AARCH64_ONLY(DEBUG_ONLY(||true)), \ 2020 "Mark all threads after a safepoint, and clear on a modify " \ 2021 "fence. Add cleanliness checks.") \ 2022 \ 2023 product(int, LockingMode, LM_LEGACY, EXPERIMENTAL, \ 2024 "Select locking mode: " \ 2025 "0: monitors only (LM_MONITOR), " \ 2026 "1: monitors & legacy stack-locking (LM_LEGACY, default), " \ 2027 "2: monitors & new lightweight locking (LM_LIGHTWEIGHT)") \ 2028 range(0, 2) \ 2029 \ 2030 product(uint, TrimNativeHeapInterval, 0, EXPERIMENTAL, \ 2031 "Interval, in ms, at which the JVM will trim the native heap if " \ 2032 "the platform supports that. Lower values will reclaim memory " \ 2033 "more eagerly at the cost of higher overhead. A value of 0 " \ 2034 "(default) disables native heap trimming.") \ 2035 range(0, UINT_MAX) \ 2036 2037 // end of RUNTIME_FLAGS 2038 2039 DECLARE_FLAGS(LP64_RUNTIME_FLAGS) 2040 DECLARE_ARCH_FLAGS(ARCH_FLAGS) 2041 DECLARE_FLAGS(RUNTIME_FLAGS) 2042 DECLARE_FLAGS(RUNTIME_OS_FLAGS) 2043 2044 #endif // SHARE_RUNTIME_GLOBALS_HPP