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 // develop_pd/product_pd flags are the same as develop/product, except that their default values 40 // are specified in platform-dependent header files. 41 42 // Flags must be declared with the following number of parameters: 43 // non-pd flags: 44 // (type, name, default_value, doc), or 45 // (type, name, default_value, extra_attrs, doc) 46 // pd flags: 47 // (type, name, doc), or 48 // (type, name, extra_attrs, doc) 49 50 // A flag must be declared with one of the following types: 51 // bool, int, uint, intx, uintx, size_t, ccstr, ccstrlist, double, or uint64_t. 52 // The type "ccstr" and "ccstrlist" are an alias for "const char*" and is used 53 // only in this file, because the macrology requires single-token type names. 54 55 // The optional extra_attrs parameter may have one of the following values: 56 // DIAGNOSTIC, EXPERIMENTAL, or MANAGEABLE. Currently extra_attrs can be used 57 // only with product/product_pd flags. 58 // 59 // DIAGNOSTIC options are not meant for VM tuning or for product modes. 60 // They are to be used for VM quality assurance or field diagnosis 61 // of VM bugs. They are hidden so that users will not be encouraged to 62 // try them as if they were VM ordinary execution options. However, they 63 // are available in the product version of the VM. Under instruction 64 // from support engineers, VM customers can turn them on to collect 65 // diagnostic information about VM problems. To use a VM diagnostic 66 // option, you must first specify +UnlockDiagnosticVMOptions. 67 // (This master switch also affects the behavior of -Xprintflags.) 68 // 69 // EXPERIMENTAL flags are in support of features that may not be 70 // an officially supported part of a product, but may be available 71 // for experimenting with. They could, for example, be performance 72 // features that may not have undergone full or rigorous QA, but which may 73 // help performance in some cases and released for experimentation 74 // by the community of users and developers. This flag also allows one to 75 // be able to build a fully supported product that nonetheless also 76 // ships with some unsupported, lightly tested, experimental features. 77 // Refer to the documentation of any products using this code for details 78 // on support and fitness for production. 79 // Like the UnlockDiagnosticVMOptions flag above, there is a corresponding 80 // UnlockExperimentalVMOptions flag, which allows the control and 81 // modification of the experimental flags. 82 // 83 // Nota bene: neither diagnostic nor experimental options should be used casually, 84 // Refer to the documentation of any products using this code for details. 85 // 86 // MANAGEABLE flags are writeable external product flags. 87 // They are dynamically writeable through the JDK management interface 88 // (com.sun.management.HotSpotDiagnosticMXBean API) and also through JConsole. 89 // These flags are external exported interface (see CSR). The list of 90 // manageable flags can be queried programmatically through the management 91 // interface. 92 // 93 // A flag can be made as "manageable" only if 94 // - the flag is defined in a CSR request as an external exported interface. 95 // - the VM implementation supports dynamic setting of the flag. 96 // This implies that the VM must *always* query the flag variable 97 // and not reuse state related to the flag state at any given time. 98 // - you want the flag to be queried programmatically by the customers. 99 // 100 101 // 102 // range is a macro that will expand to min and max arguments for range 103 // checking code if provided - see jvmFlagLimit.hpp 104 // 105 // constraint is a macro that will expand to custom function call 106 // for constraint checking if provided - see jvmFlagLimit.hpp 107 108 // Default and minimum StringTable and SymbolTable size values 109 // Must be powers of 2 110 const size_t defaultStringTableSize = NOT_LP64(1024) LP64_ONLY(65536); 111 const size_t minimumStringTableSize = 128; 112 const size_t defaultSymbolTableSize = 32768; // 2^15 113 const size_t minimumSymbolTableSize = 1024; 114 115 #ifdef _LP64 116 #define LP64_RUNTIME_FLAGS(develop, \ 117 develop_pd, \ 118 product, \ 119 product_pd, \ 120 range, \ 121 constraint) \ 122 \ 123 product(bool, UseCompressedOops, false, \ 124 "Use 32-bit object references in 64-bit VM. " \ 125 "lp64_product means flag is always constant in 32 bit VM") \ 126 \ 127 product(bool, UseCompressedClassPointers, true, \ 128 "Use 32-bit class pointers in 64-bit VM. " \ 129 "lp64_product means flag is always constant in 32 bit VM") \ 130 \ 131 product(int, ObjectAlignmentInBytes, 8, \ 132 "Default object alignment in bytes, 8 is minimum") \ 133 range(8, 256) \ 134 constraint(ObjectAlignmentInBytesConstraintFunc, AtParse) 135 136 #else 137 // !_LP64 138 139 #define LP64_RUNTIME_FLAGS(develop, \ 140 develop_pd, \ 141 product, \ 142 product_pd, \ 143 range, \ 144 constraint) 145 const bool UseCompressedOops = false; 146 const bool UseCompressedClassPointers = false; 147 const int ObjectAlignmentInBytes = 8; 148 149 #endif // _LP64 150 151 #define RUNTIME_FLAGS(develop, \ 152 develop_pd, \ 153 product, \ 154 product_pd, \ 155 range, \ 156 constraint) \ 157 \ 158 develop(bool, CheckCompressedOops, true, \ 159 "Generate checks in encoding/decoding code in debug VM") \ 160 \ 161 product(uintx, HeapSearchSteps, 3 PPC64_ONLY(+17), \ 162 "Heap allocation steps through preferred address regions to find" \ 163 " where it can allocate the heap. Number of steps to take per " \ 164 "region.") \ 165 range(1, max_uintx) \ 166 \ 167 product(uint, HandshakeTimeout, 0, DIAGNOSTIC, \ 168 "If nonzero set a timeout in milliseconds for handshakes") \ 169 \ 170 product(bool, AlwaysSafeConstructors, false, EXPERIMENTAL, \ 171 "Force safe construction, as if all fields are final.") \ 172 \ 173 product(bool, UnlockDiagnosticVMOptions, trueInDebug, DIAGNOSTIC, \ 174 "Enable normal processing of flags relating to field diagnostics")\ 175 \ 176 product(bool, UnlockExperimentalVMOptions, false, EXPERIMENTAL, \ 177 "Enable normal processing of flags relating to experimental " \ 178 "features") \ 179 \ 180 product(bool, JavaMonitorsInStackTrace, true, \ 181 "Print information about Java monitor locks when the stacks are " \ 182 "dumped") \ 183 \ 184 product_pd(bool, UseLargePages, \ 185 "Use large page memory") \ 186 \ 187 product_pd(bool, UseLargePagesIndividualAllocation, \ 188 "Allocate large pages individually for better affinity") \ 189 \ 190 develop(bool, LargePagesIndividualAllocationInjectError, false, \ 191 "Fail large pages individual allocation") \ 192 \ 193 product(bool, UseNUMA, false, \ 194 "Use NUMA if available") \ 195 \ 196 product(bool, UseNUMAInterleaving, false, \ 197 "Interleave memory across NUMA nodes if available") \ 198 \ 199 product(size_t, NUMAInterleaveGranularity, 2*M, \ 200 "Granularity to use for NUMA interleaving on Windows OS") \ 201 constraint(NUMAInterleaveGranularityConstraintFunc, AtParse) \ 202 \ 203 product(uintx, NUMAChunkResizeWeight, 20, \ 204 "Percentage (0-100) used to weight the current sample when " \ 205 "computing exponentially decaying average for " \ 206 "AdaptiveNUMAChunkSizing") \ 207 range(0, 100) \ 208 \ 209 product(size_t, NUMASpaceResizeRate, 1*G, \ 210 "Do not reallocate more than this amount per collection") \ 211 range(0, max_uintx) \ 212 \ 213 product(bool, UseAdaptiveNUMAChunkSizing, true, \ 214 "Enable adaptive chunk sizing for NUMA") \ 215 \ 216 product(bool, NUMAStats, false, \ 217 "Print NUMA stats in detailed heap information") \ 218 \ 219 product(bool, UseAES, false, \ 220 "Control whether AES instructions are used when available") \ 221 \ 222 product(bool, UseFMA, false, \ 223 "Control whether FMA instructions are used when available") \ 224 \ 225 product(bool, UseSHA, false, \ 226 "Control whether SHA instructions are used when available") \ 227 \ 228 product(bool, UseGHASHIntrinsics, false, DIAGNOSTIC, \ 229 "Use intrinsics for GHASH versions of crypto") \ 230 \ 231 product(bool, UseBASE64Intrinsics, false, \ 232 "Use intrinsics for java.util.Base64") \ 233 \ 234 product(bool, UsePoly1305Intrinsics, false, DIAGNOSTIC, \ 235 "Use intrinsics for sun.security.util.math.intpoly") \ 236 product(bool, UseIntPolyIntrinsics, false, DIAGNOSTIC, \ 237 "Use intrinsics for sun.security.util.math.intpoly.MontgomeryIntegerPolynomialP256") \ 238 \ 239 product(size_t, LargePageSizeInBytes, 0, \ 240 "Maximum large page size used (0 will use the default large " \ 241 "page size for the environment as the maximum)") \ 242 range(0, max_uintx) \ 243 \ 244 product(size_t, LargePageHeapSizeThreshold, 128*M, \ 245 "Use large pages if maximum heap is at least this big") \ 246 range(0, max_uintx) \ 247 \ 248 product(bool, ForceTimeHighResolution, false, \ 249 "Using high time resolution (for Win32 only)") \ 250 \ 251 develop(bool, TracePcPatching, false, \ 252 "Trace usage of frame::patch_pc") \ 253 \ 254 develop(bool, TraceRelocator, false, \ 255 "Trace the bytecode relocator") \ 256 \ 257 \ 258 product(bool, SafepointALot, false, DIAGNOSTIC, \ 259 "Generate a lot of safepoints. This works with " \ 260 "GuaranteedSafepointInterval") \ 261 \ 262 product(bool, HandshakeALot, false, DIAGNOSTIC, \ 263 "Generate a lot of handshakes. This works with " \ 264 "GuaranteedSafepointInterval") \ 265 \ 266 product_pd(bool, BackgroundCompilation, \ 267 "A thread requesting compilation is not blocked during " \ 268 "compilation") \ 269 \ 270 product(bool, MethodFlushing, true, \ 271 "Reclamation of compiled methods") \ 272 \ 273 develop(bool, VerifyStack, false, \ 274 "Verify stack of each thread when it is entering a runtime call") \ 275 \ 276 product(bool, ForceUnreachable, false, DIAGNOSTIC, \ 277 "Make all non code cache addresses to be unreachable by " \ 278 "forcing use of 64bit literal fixups") \ 279 \ 280 develop(bool, TraceDerivedPointers, false, \ 281 "Trace traversal of derived pointers on stack") \ 282 \ 283 develop(bool, TraceCodeBlobStacks, false, \ 284 "Trace stack-walk of codeblobs") \ 285 \ 286 develop(bool, PrintRewrites, false, \ 287 "Print methods that are being rewritten") \ 288 \ 289 product(bool, UseInlineCaches, true, \ 290 "Use Inline Caches for virtual calls ") \ 291 \ 292 product(size_t, InlineCacheBufferSize, 10*K, EXPERIMENTAL, \ 293 "InlineCacheBuffer size") \ 294 \ 295 product(bool, InlineArrayCopy, true, DIAGNOSTIC, \ 296 "Inline arraycopy native that is known to be part of " \ 297 "base library DLL") \ 298 \ 299 product(bool, InlineObjectHash, true, DIAGNOSTIC, \ 300 "Inline Object::hashCode() native that is known to be part " \ 301 "of base library DLL") \ 302 \ 303 product(bool, InlineNatives, true, DIAGNOSTIC, \ 304 "Inline natives that are known to be part of base library DLL") \ 305 \ 306 product(bool, InlineMathNatives, true, DIAGNOSTIC, \ 307 "Inline SinD, CosD, etc.") \ 308 \ 309 product(bool, InlineClassNatives, true, DIAGNOSTIC, \ 310 "Inline Class.isInstance, etc") \ 311 \ 312 product(bool, InlineThreadNatives, true, DIAGNOSTIC, \ 313 "Inline Thread.currentThread, etc") \ 314 \ 315 product(bool, InlineUnsafeOps, true, DIAGNOSTIC, \ 316 "Inline memory ops (native methods) from Unsafe") \ 317 \ 318 product(bool, UseAESIntrinsics, false, DIAGNOSTIC, \ 319 "Use intrinsics for AES versions of crypto") \ 320 \ 321 product(bool, UseAESCTRIntrinsics, false, DIAGNOSTIC, \ 322 "Use intrinsics for the paralleled version of AES/CTR crypto") \ 323 \ 324 product(bool, UseChaCha20Intrinsics, false, DIAGNOSTIC, \ 325 "Use intrinsics for the vectorized version of ChaCha20") \ 326 \ 327 product(bool, UseMD5Intrinsics, false, DIAGNOSTIC, \ 328 "Use intrinsics for MD5 crypto hash function") \ 329 \ 330 product(bool, UseSHA1Intrinsics, false, DIAGNOSTIC, \ 331 "Use intrinsics for SHA-1 crypto hash function. " \ 332 "Requires that UseSHA is enabled.") \ 333 \ 334 product(bool, UseSHA256Intrinsics, false, DIAGNOSTIC, \ 335 "Use intrinsics for SHA-224 and SHA-256 crypto hash functions. " \ 336 "Requires that UseSHA is enabled.") \ 337 \ 338 product(bool, UseSHA512Intrinsics, false, DIAGNOSTIC, \ 339 "Use intrinsics for SHA-384 and SHA-512 crypto hash functions. " \ 340 "Requires that UseSHA is enabled.") \ 341 \ 342 product(bool, UseSHA3Intrinsics, false, DIAGNOSTIC, \ 343 "Use intrinsics for SHA3 crypto hash function. " \ 344 "Requires that UseSHA is enabled.") \ 345 \ 346 product(bool, UseCRC32Intrinsics, false, DIAGNOSTIC, \ 347 "use intrinsics for java.util.zip.CRC32") \ 348 \ 349 product(bool, UseCRC32CIntrinsics, false, DIAGNOSTIC, \ 350 "use intrinsics for java.util.zip.CRC32C") \ 351 \ 352 product(bool, UseAdler32Intrinsics, false, DIAGNOSTIC, \ 353 "use intrinsics for java.util.zip.Adler32") \ 354 \ 355 product(bool, UseVectorizedMismatchIntrinsic, false, DIAGNOSTIC, \ 356 "Enables intrinsification of ArraysSupport.vectorizedMismatch()") \ 357 \ 358 product(bool, UseVectorizedHashCodeIntrinsic, false, DIAGNOSTIC, \ 359 "Enables intrinsification of ArraysSupport.vectorizedHashCode()") \ 360 \ 361 product(bool, UseCopySignIntrinsic, false, DIAGNOSTIC, \ 362 "Enables intrinsification of Math.copySign") \ 363 \ 364 product(bool, UseSignumIntrinsic, false, DIAGNOSTIC, \ 365 "Enables intrinsification of Math.signum") \ 366 \ 367 product_pd(bool, DelayCompilerStubsGeneration, DIAGNOSTIC, \ 368 "Use Compiler thread for compiler's stubs generation") \ 369 \ 370 product(ccstrlist, DisableIntrinsic, "", DIAGNOSTIC, \ 371 "do not expand intrinsics whose (internal) names appear here") \ 372 constraint(DisableIntrinsicConstraintFunc,AfterErgo) \ 373 \ 374 product(ccstrlist, ControlIntrinsic, "", DIAGNOSTIC, \ 375 "Control intrinsics using a list of +/- (internal) names, " \ 376 "separated by commas") \ 377 constraint(ControlIntrinsicConstraintFunc,AfterErgo) \ 378 \ 379 develop(bool, TraceCallFixup, false, \ 380 "Trace all call fixups") \ 381 \ 382 develop(bool, DeoptimizeALot, false, \ 383 "Deoptimize at every exit from the runtime system") \ 384 \ 385 develop(ccstrlist, DeoptimizeOnlyAt, "", \ 386 "A comma separated list of bcis to deoptimize at") \ 387 \ 388 develop(bool, DeoptimizeRandom, false, \ 389 "Deoptimize random frames on random exit from the runtime system")\ 390 \ 391 develop(bool, ZombieALot, false, \ 392 "Create non-entrant nmethods at exit from the runtime system") \ 393 \ 394 develop(bool, WalkStackALot, false, \ 395 "Trace stack (no print) at every exit from the runtime system") \ 396 \ 397 develop(bool, DeoptimizeObjectsALot, false, \ 398 "For testing purposes concurrent threads revert optimizations " \ 399 "based on escape analysis at intervals given with " \ 400 "DeoptimizeObjectsALotInterval=n. The thread count is given " \ 401 "with DeoptimizeObjectsALotThreadCountSingle and " \ 402 "DeoptimizeObjectsALotThreadCountAll.") \ 403 \ 404 develop(uint64_t, DeoptimizeObjectsALotInterval, 5, \ 405 "Interval for DeoptimizeObjectsALot.") \ 406 range(0, max_jlong) \ 407 \ 408 develop(int, DeoptimizeObjectsALotThreadCountSingle, 1, \ 409 "The number of threads that revert optimizations based on " \ 410 "escape analysis for a single thread if DeoptimizeObjectsALot " \ 411 "is enabled. The target thread is selected round robin." ) \ 412 range(0, max_jint) \ 413 \ 414 develop(int, DeoptimizeObjectsALotThreadCountAll, 1, \ 415 "The number of threads that revert optimizations based on " \ 416 "escape analysis for all threads if DeoptimizeObjectsALot " \ 417 "is enabled." ) \ 418 range(0, max_jint) \ 419 \ 420 develop(bool, VerifyLastFrame, false, \ 421 "Verify oops on last frame on entry to VM") \ 422 \ 423 product(bool, SafepointTimeout, false, \ 424 "Time out and warn or fail after SafepointTimeoutDelay " \ 425 "milliseconds if failed to reach safepoint") \ 426 \ 427 product(bool, AbortVMOnSafepointTimeout, false, DIAGNOSTIC, \ 428 "Abort upon failure to reach safepoint (see SafepointTimeout)") \ 429 \ 430 product(uint64_t, AbortVMOnSafepointTimeoutDelay, 0, DIAGNOSTIC, \ 431 "Delay in milliseconds for option AbortVMOnSafepointTimeout") \ 432 range(0, max_jlong) \ 433 \ 434 product(bool, AbortVMOnVMOperationTimeout, false, DIAGNOSTIC, \ 435 "Abort upon failure to complete VM operation promptly") \ 436 \ 437 product(intx, AbortVMOnVMOperationTimeoutDelay, 1000, DIAGNOSTIC, \ 438 "Delay in milliseconds for option AbortVMOnVMOperationTimeout") \ 439 range(0, max_intx) \ 440 \ 441 product(bool, MaxFDLimit, true, \ 442 "Bump the number of file descriptors to maximum (Unix only)") \ 443 \ 444 product(bool, LogEvents, true, DIAGNOSTIC, \ 445 "Enable the various ring buffer event logs") \ 446 \ 447 product(int, LogEventsBufferEntries, 20, DIAGNOSTIC, \ 448 "Number of ring buffer event logs") \ 449 range(1, NOT_LP64(1*K) LP64_ONLY(1*M)) \ 450 \ 451 product(bool, BytecodeVerificationRemote, true, DIAGNOSTIC, \ 452 "Enable the Java bytecode verifier for remote classes") \ 453 \ 454 product(bool, BytecodeVerificationLocal, false, DIAGNOSTIC, \ 455 "Enable the Java bytecode verifier for local classes") \ 456 \ 457 develop(bool, VerifyStackAtCalls, false, \ 458 "Verify that the stack pointer is unchanged after calls") \ 459 \ 460 develop(bool, TraceJavaAssertions, false, \ 461 "Trace java language assertions") \ 462 \ 463 develop(bool, VerifyCodeCache, false, \ 464 "Verify code cache on memory allocation/deallocation") \ 465 \ 466 develop(bool, ZapResourceArea, trueInDebug, \ 467 "Zap freed resource/arena space") \ 468 \ 469 develop(bool, ZapVMHandleArea, trueInDebug, \ 470 "Zap freed VM handle space") \ 471 \ 472 develop(bool, ZapStackSegments, trueInDebug, \ 473 "Zap allocated/freed stack segments") \ 474 \ 475 develop(bool, ZapUnusedHeapArea, trueInDebug, \ 476 "Zap unused heap space") \ 477 \ 478 develop(bool, ZapFillerObjects, trueInDebug, \ 479 "Zap filler objects") \ 480 \ 481 develop(bool, ZapTLAB, trueInDebug, \ 482 "Zap allocated TLABs") \ 483 \ 484 product(bool, ExecutingUnitTests, false, \ 485 "Whether the JVM is running unit tests or not") \ 486 \ 487 develop(uint, ErrorHandlerTest, 0, \ 488 "If > 0, provokes an error after VM initialization; the value " \ 489 "determines which error to provoke. See controlled_crash() " \ 490 "in vmError.cpp.") \ 491 range(0, 17) \ 492 \ 493 develop(uint, TestCrashInErrorHandler, 0, \ 494 "If > 0, provokes an error inside VM error handler (a secondary " \ 495 "crash). see controlled_crash() in vmError.cpp") \ 496 range(0, 17) \ 497 \ 498 develop(bool, TestSafeFetchInErrorHandler, false , \ 499 "If true, tests SafeFetch inside error handler.") \ 500 \ 501 develop(bool, TestUnresponsiveErrorHandler, false, \ 502 "If true, simulates an unresponsive error handler.") \ 503 \ 504 develop(bool, Verbose, false, \ 505 "Print additional debugging information from other modes") \ 506 \ 507 develop(bool, PrintMiscellaneous, false, \ 508 "Print uncategorized debugging information (requires +Verbose)") \ 509 \ 510 develop(bool, WizardMode, false, \ 511 "Print much more debugging information") \ 512 \ 513 product(bool, ShowMessageBoxOnError, false, \ 514 "Keep process alive on VM fatal error") \ 515 \ 516 product(bool, CreateCoredumpOnCrash, true, \ 517 "Create core/mini dump on VM fatal error") \ 518 \ 519 product(uint64_t, ErrorLogTimeout, 2 * 60, \ 520 "Timeout, in seconds, to limit the time spent on writing an " \ 521 "error log in case of a crash.") \ 522 range(0, (uint64_t)max_jlong/1000) \ 523 \ 524 product(bool, ErrorLogSecondaryErrorDetails, false, DIAGNOSTIC, \ 525 "If enabled, show details on secondary crashes in the error log") \ 526 \ 527 develop(intx, TraceDwarfLevel, 0, \ 528 "Debug levels for the dwarf parser") \ 529 range(0, 4) \ 530 \ 531 product(bool, SuppressFatalErrorMessage, false, \ 532 "Report NO fatal error message (avoid deadlock)") \ 533 \ 534 product(ccstrlist, OnError, "", \ 535 "Run user-defined commands on fatal error; see VMError.cpp " \ 536 "for examples") \ 537 \ 538 product(ccstrlist, OnOutOfMemoryError, "", \ 539 "Run user-defined commands on first java.lang.OutOfMemoryError " \ 540 "thrown from JVM") \ 541 \ 542 product(bool, HeapDumpBeforeFullGC, false, MANAGEABLE, \ 543 "Dump heap to file before any major stop-the-world GC " \ 544 "(also see FullGCHeapDumpLimit, HeapDumpPath, HeapDumpGzipLevel)")\ 545 \ 546 product(bool, HeapDumpAfterFullGC, false, MANAGEABLE, \ 547 "Dump heap to file after any major stop-the-world GC " \ 548 "(also see FullGCHeapDumpLimit, HeapDumpPath, HeapDumpGzipLevel)")\ 549 \ 550 product(uint, FullGCHeapDumpLimit, 0, MANAGEABLE, \ 551 "Limit the number of heap dumps triggered by " \ 552 "HeapDumpBeforeFullGC or HeapDumpAfterFullGC " \ 553 "(0 means no limit)") \ 554 \ 555 product(bool, HeapDumpOnOutOfMemoryError, false, MANAGEABLE, \ 556 "Dump heap to file when java.lang.OutOfMemoryError is thrown " \ 557 "from JVM " \ 558 "(also see HeapDumpPath, HeapDumpGzipLevel)") \ 559 \ 560 product(ccstr, HeapDumpPath, nullptr, MANAGEABLE, \ 561 "When HeapDumpOnOutOfMemoryError, HeapDumpBeforeFullGC " \ 562 "or HeapDumpAfterFullGC is on, the path (filename or " \ 563 "directory) of the dump file (defaults to java_pid<pid>.hprof " \ 564 "in the working directory)") \ 565 \ 566 product(int, HeapDumpGzipLevel, 0, MANAGEABLE, \ 567 "When HeapDumpOnOutOfMemoryError, HeapDumpBeforeFullGC " \ 568 "or HeapDumpAfterFullGC is on, the gzip compression " \ 569 "level of the dump file. 0 (the default) disables gzip " \ 570 "compression. Otherwise the level must be between 1 and 9.") \ 571 range(0, 9) \ 572 \ 573 product(ccstr, NativeMemoryTracking, DEBUG_ONLY("summary") NOT_DEBUG("off"), \ 574 "Native memory tracking options") \ 575 \ 576 product(bool, PrintNMTStatistics, false, DIAGNOSTIC, \ 577 "Print native memory tracking summary data if it is on") \ 578 \ 579 product(bool, LogCompilation, false, DIAGNOSTIC, \ 580 "Log compilation activity in detail to LogFile") \ 581 \ 582 product(bool, PrintCompilation, false, \ 583 "Print compilations") \ 584 \ 585 product(intx, RepeatCompilation, 0, DIAGNOSTIC, \ 586 "Repeat compilation without installing code (number of times)") \ 587 range(0, max_jint) \ 588 \ 589 product(bool, PrintExtendedThreadInfo, false, \ 590 "Print more information in thread dump") \ 591 \ 592 product(intx, ScavengeRootsInCode, 2, DIAGNOSTIC, \ 593 "0: do not allow scavengable oops in the code cache; " \ 594 "1: allow scavenging from the code cache; " \ 595 "2: emit as many constants as the compiler can see") \ 596 range(0, 2) \ 597 \ 598 product(bool, AlwaysRestoreFPU, false, \ 599 "Restore the FPU control word after every JNI call (expensive)") \ 600 \ 601 product(bool, PrintCompilation2, false, DIAGNOSTIC, \ 602 "Print additional statistics per compilation") \ 603 \ 604 product(bool, PrintAdapterHandlers, false, DIAGNOSTIC, \ 605 "Print code generated for i2c/c2i adapters") \ 606 \ 607 product(bool, VerifyAdapterCalls, trueInDebug, DIAGNOSTIC, \ 608 "Verify that i2c/c2i adapters are called properly") \ 609 \ 610 develop(bool, VerifyAdapterSharing, false, \ 611 "Verify that the code for shared adapters is the equivalent") \ 612 \ 613 product(bool, PrintAssembly, false, DIAGNOSTIC, \ 614 "Print assembly code (using external disassembler.so)") \ 615 \ 616 product(ccstr, PrintAssemblyOptions, nullptr, DIAGNOSTIC, \ 617 "Print options string passed to disassembler.so") \ 618 \ 619 develop(bool, PrintNMethodStatistics, false, \ 620 "Print a summary statistic for the generated nmethods") \ 621 \ 622 product(bool, PrintNMethods, false, DIAGNOSTIC, \ 623 "Print assembly code for nmethods when generated") \ 624 \ 625 product(bool, PrintNativeNMethods, false, DIAGNOSTIC, \ 626 "Print assembly code for native nmethods when generated") \ 627 \ 628 develop(bool, PrintDebugInfo, false, \ 629 "Print debug information for all nmethods when generated") \ 630 \ 631 develop(bool, PrintRelocations, false, \ 632 "Print relocation information for all nmethods when generated") \ 633 \ 634 develop(bool, PrintDependencies, false, \ 635 "Print dependency information for all nmethods when generated") \ 636 \ 637 develop(bool, PrintExceptionHandlers, false, \ 638 "Print exception handler tables for all nmethods when generated") \ 639 \ 640 develop(bool, StressCompiledExceptionHandlers, false, \ 641 "Exercise compiled exception handlers") \ 642 \ 643 develop(bool, InterceptOSException, false, \ 644 "Start debugger when an implicit OS (e.g. null pointer) " \ 645 "exception happens") \ 646 \ 647 product(bool, PrintCodeCache, false, \ 648 "Print the code cache memory usage when exiting") \ 649 \ 650 develop(bool, PrintCodeCache2, false, \ 651 "Print detailed usage information on the code cache when exiting")\ 652 \ 653 product(bool, PrintCodeCacheOnCompilation, false, \ 654 "Print the code cache memory usage each time a method is " \ 655 "compiled") \ 656 \ 657 product(bool, PrintCodeHeapAnalytics, false, DIAGNOSTIC, \ 658 "Print code heap usage statistics on exit and on full condition") \ 659 \ 660 product(bool, PrintStubCode, false, DIAGNOSTIC, \ 661 "Print generated stub code") \ 662 \ 663 product(bool, StackTraceInThrowable, true, \ 664 "Collect backtrace in throwable when exception happens") \ 665 \ 666 product(bool, OmitStackTraceInFastThrow, true, \ 667 "Omit backtraces for some 'hot' exceptions in optimized code") \ 668 \ 669 product(bool, ShowCodeDetailsInExceptionMessages, true, MANAGEABLE, \ 670 "Show exception messages from RuntimeExceptions that contain " \ 671 "snippets of the failing code. Disable this to improve privacy.") \ 672 \ 673 product(bool, PrintWarnings, true, \ 674 "Print JVM warnings to output stream") \ 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 develop(bool, PrintSystemDictionaryAtExit, false, \ 693 "Print the system dictionary at exit") \ 694 \ 695 develop(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 "(Deprecated) 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, MonitorUnlinkBatch, 500, DIAGNOSTIC, \ 740 "The maximum number of monitors to unlink in one batch. ") \ 741 range(1, max_jint) \ 742 \ 743 product(int, MonitorUsedDeflationThreshold, 90, DIAGNOSTIC, \ 744 "Percentage of used monitors before triggering deflation (0 is " \ 745 "off). The check is performed on AsyncDeflationInterval or " \ 746 "GuaranteedAsyncDeflationInterval, whichever is lower.") \ 747 range(0, 100) \ 748 \ 749 product(uintx, NoAsyncDeflationProgressMax, 3, DIAGNOSTIC, \ 750 "Max number of no progress async deflation attempts to tolerate " \ 751 "before adjusting the in_use_list_ceiling up (0 is off).") \ 752 range(0, max_uintx) \ 753 \ 754 product(intx, hashCode, 5, EXPERIMENTAL, \ 755 "(Unstable) select hashCode generation algorithm") \ 756 \ 757 product(bool, ReduceSignalUsage, false, \ 758 "Reduce the use of OS signals in Java and/or the VM") \ 759 \ 760 develop(bool, LoadLineNumberTables, true, \ 761 "Tell whether the class file parser loads line number tables") \ 762 \ 763 develop(bool, LoadLocalVariableTables, true, \ 764 "Tell whether the class file parser loads local variable tables") \ 765 \ 766 develop(bool, LoadLocalVariableTypeTables, true, \ 767 "Tell whether the class file parser loads local variable type" \ 768 "tables") \ 769 \ 770 product(bool, AllowUserSignalHandlers, false, \ 771 "Application will install primary signal handlers for the JVM " \ 772 "(Unix only)") \ 773 \ 774 product(bool, UseSignalChaining, true, \ 775 "Use signal-chaining to invoke signal handlers installed " \ 776 "by the application (Unix only)") \ 777 \ 778 product(bool, RestoreMXCSROnJNICalls, false, \ 779 "Restore MXCSR when returning from JNI calls") \ 780 \ 781 product(bool, CheckJNICalls, false, \ 782 "Verify all arguments to JNI calls") \ 783 \ 784 product(bool, UseFastJNIAccessors, true, \ 785 "Use optimized versions of Get<Primitive>Field") \ 786 \ 787 product(intx, MaxJNILocalCapacity, 65536, \ 788 "Maximum allowable local JNI handle capacity to " \ 789 "EnsureLocalCapacity() and PushLocalFrame(), " \ 790 "where <= 0 is unlimited, default: 65536") \ 791 range(min_intx, max_intx) \ 792 \ 793 product(bool, EagerXrunInit, false, \ 794 "Eagerly initialize -Xrun libraries; allows startup profiling, " \ 795 "but not all -Xrun libraries may support the state of the VM " \ 796 "at this time") \ 797 \ 798 product(bool, PreserveAllAnnotations, false, \ 799 "(Deprecated) Preserve RuntimeInvisibleAnnotations as well " \ 800 "as RuntimeVisibleAnnotations") \ 801 \ 802 develop(uintx, PreallocatedOutOfMemoryErrorCount, 4, \ 803 "Number of OutOfMemoryErrors preallocated with backtrace") \ 804 \ 805 product(bool, UseXMMForArrayCopy, false, \ 806 "Use SSE2 MOVQ instruction for Arraycopy") \ 807 \ 808 product(bool, PrintFieldLayout, false, DIAGNOSTIC, \ 809 "Print field layout for each class") \ 810 \ 811 product(bool, PrintInlineLayout, false, DIAGNOSTIC, \ 812 "Print field layout for each inline type or class with inline fields") \ 813 \ 814 product(bool, PrintFlatArrayLayout, false, DIAGNOSTIC, \ 815 "Print array layout for each inline type array") \ 816 \ 817 product(intx, FlatArrayElementMaxSize, -1, \ 818 "Max size for flattening inline array elements, <0 no limit") \ 819 \ 820 product(intx, InlineFieldMaxFlatSize, 128, \ 821 "Max size for flattening inline type fields, <0 no limit") \ 822 \ 823 develop(bool, EnableNullableFieldFlattening, false, \ 824 "Allow the JVM to flatten some nullable fields") \ 825 \ 826 product(intx, FlatArrayElementMaxOops, 4, \ 827 "Max nof embedded object references in an inline type to flatten, <0 no limit") \ 828 \ 829 product(bool, InlineArrayAtomicAccess, false, \ 830 "Atomic inline array accesses by-default, for all inline arrays") \ 831 \ 832 /* Need to limit the extent of the padding to reasonable size. */\ 833 /* 8K is well beyond the reasonable HW cache line size, even with */\ 834 /* aggressive prefetching, while still leaving the room for segregating */\ 835 /* among the distinct pages. */\ 836 product(int, ContendedPaddingWidth, 128, \ 837 "How many bytes to pad the fields/classes marked @Contended with")\ 838 range(0, 8192) \ 839 constraint(ContendedPaddingWidthConstraintFunc,AfterErgo) \ 840 \ 841 product(bool, EnableContended, true, \ 842 "Enable @Contended annotation support") \ 843 \ 844 product(bool, RestrictContended, true, \ 845 "Restrict @Contended to trusted classes") \ 846 \ 847 product(int, DiagnoseSyncOnValueBasedClasses, 0, DIAGNOSTIC, \ 848 "Detect and take action upon identifying synchronization on " \ 849 "value based classes. Modes: " \ 850 "0: off; " \ 851 "1: exit with fatal error; " \ 852 "2: log message to stdout. Output file can be specified with " \ 853 " -Xlog:valuebasedclasses. If JFR is running it will " \ 854 " also generate JFR events.") \ 855 range(0, 2) \ 856 \ 857 product(bool, ExitOnOutOfMemoryError, false, \ 858 "JVM exits on the first occurrence of an out-of-memory error " \ 859 "thrown from JVM") \ 860 \ 861 product(bool, CrashOnOutOfMemoryError, false, \ 862 "JVM aborts, producing an error log and core/mini dump, on the " \ 863 "first occurrence of an out-of-memory error thrown from JVM") \ 864 \ 865 product(intx, UserThreadWaitAttemptsAtExit, 30, \ 866 "The number of times to wait for user threads to stop executing " \ 867 "native code during JVM exit. Each wait lasts 10 milliseconds. " \ 868 "The maximum number of waits is 1000, to wait at most 10 " \ 869 "seconds.") \ 870 range(0, 1000) \ 871 \ 872 /* tracing */ \ 873 \ 874 develop(bool, StressRewriter, false, \ 875 "Stress linktime bytecode rewriting") \ 876 \ 877 product(ccstr, TraceJVMTI, nullptr, \ 878 "Trace flags for JVMTI functions and events") \ 879 \ 880 product(bool, StressLdcRewrite, false, DIAGNOSTIC, \ 881 "Force ldc -> ldc_w rewrite during RedefineClasses. " \ 882 "This option can change an EMCP method into an obsolete method " \ 883 "and can affect tests that expect specific methods to be EMCP. " \ 884 "This option should be used with caution.") \ 885 \ 886 product(bool, AllowRedefinitionToAddDeleteMethods, false, \ 887 "(Deprecated) Allow redefinition to add and delete private " \ 888 "static or final methods for compatibility with old releases") \ 889 \ 890 develop(bool, TraceBytecodes, false, \ 891 "Trace bytecode execution") \ 892 \ 893 develop(bool, TraceBytecodesTruncated, false, \ 894 "Truncate non control-flow bytecode when tracing bytecode") \ 895 \ 896 develop(bool, VerifyDependencies, trueInDebug, \ 897 "Exercise and verify the compilation dependency mechanism") \ 898 \ 899 develop(bool, TraceNewOopMapGeneration, false, \ 900 "Trace OopMapGeneration") \ 901 \ 902 develop(bool, TraceNewOopMapGenerationDetailed, false, \ 903 "Trace OopMapGeneration: print detailed cell states") \ 904 \ 905 develop(bool, TimeOopMap, false, \ 906 "Time calls to GenerateOopMap::compute_map() in sum") \ 907 \ 908 develop(bool, TimeOopMap2, false, \ 909 "Time calls to GenerateOopMap::compute_map() individually") \ 910 \ 911 develop(bool, TraceOopMapRewrites, false, \ 912 "Trace rewriting of methods during oop map generation") \ 913 \ 914 develop(bool, TraceFinalizerRegistration, false, \ 915 "Trace registration of final references") \ 916 \ 917 product(bool, IgnoreEmptyClassPaths, false, \ 918 "Ignore empty path elements in -classpath") \ 919 \ 920 product(bool, PrintHeapAtSIGBREAK, true, \ 921 "Print heap layout in response to SIGBREAK") \ 922 \ 923 product(bool, PrintClassHistogram, false, MANAGEABLE, \ 924 "Print a histogram of class instances") \ 925 \ 926 product(double, ObjectCountCutOffPercent, 0.5, EXPERIMENTAL, \ 927 "The percentage of the used heap that the instances of a class " \ 928 "must occupy for the class to generate a trace event") \ 929 range(0.0, 100.0) \ 930 \ 931 /* JVMTI heap profiling */ \ 932 \ 933 product(bool, VerifyBeforeIteration, false, DIAGNOSTIC, \ 934 "Verify memory system before JVMTI iteration") \ 935 \ 936 /* compiler */ \ 937 \ 938 /* notice: the max range value here is max_jint, not max_intx */ \ 939 /* because of overflow issue */ \ 940 product(intx, CICompilerCount, CI_COMPILER_COUNT, \ 941 "Number of compiler threads to run") \ 942 range(0, max_jint) \ 943 constraint(CICompilerCountConstraintFunc, AfterErgo) \ 944 \ 945 product(bool, UseDynamicNumberOfCompilerThreads, true, \ 946 "Dynamically choose the number of parallel compiler threads") \ 947 \ 948 product(bool, ReduceNumberOfCompilerThreads, true, DIAGNOSTIC, \ 949 "Reduce the number of parallel compiler threads when they " \ 950 "are not used") \ 951 \ 952 product(bool, TraceCompilerThreads, false, DIAGNOSTIC, \ 953 "Trace creation and removal of compiler threads") \ 954 \ 955 product(ccstr, LogClassLoadingCauseFor, nullptr, \ 956 "Apply -Xlog:class+load+cause* to classes whose fully " \ 957 "qualified name contains this string (\"*\" matches " \ 958 "any class).") \ 959 \ 960 develop(bool, InjectCompilerCreationFailure, false, \ 961 "Inject thread creation failures for " \ 962 "UseDynamicNumberOfCompilerThreads") \ 963 \ 964 develop(bool, GenerateSynchronizationCode, true, \ 965 "generate locking/unlocking code for synchronized methods and " \ 966 "monitors") \ 967 \ 968 product_pd(bool, ImplicitNullChecks, DIAGNOSTIC, \ 969 "Generate code for implicit null checks") \ 970 \ 971 product_pd(bool, TrapBasedNullChecks, \ 972 "Generate code for null checks that uses a cmp and trap " \ 973 "instruction raising SIGTRAP. This is only used if an access to" \ 974 "null (+offset) will not raise a SIGSEGV, i.e.," \ 975 "ImplicitNullChecks don't work (PPC64).") \ 976 \ 977 product(bool, EnableThreadSMRStatistics, trueInDebug, DIAGNOSTIC, \ 978 "Enable Thread SMR Statistics") \ 979 \ 980 product(bool, UseNotificationThread, true, \ 981 "(Deprecated) Use Notification Thread") \ 982 \ 983 product(bool, Inline, true, \ 984 "Enable inlining") \ 985 \ 986 product(bool, ClipInlining, true, \ 987 "Clip inlining if aggregate method exceeds DesiredMethodLimit") \ 988 \ 989 develop(bool, UseCHA, true, \ 990 "Enable CHA") \ 991 \ 992 product(bool, UseVtableBasedCHA, true, DIAGNOSTIC, \ 993 "Use vtable information during CHA") \ 994 \ 995 product(bool, UseTypeProfile, true, \ 996 "Check interpreter profile for historically monomorphic calls") \ 997 \ 998 product(bool, PrintInlining, false, DIAGNOSTIC, \ 999 "Print inlining optimizations") \ 1000 \ 1001 product(bool, UsePopCountInstruction, false, \ 1002 "Use population count instruction") \ 1003 \ 1004 develop(bool, TraceMethodReplacement, false, \ 1005 "Print when methods are replaced do to recompilation") \ 1006 \ 1007 product(intx, MinPassesBeforeFlush, 10, DIAGNOSTIC, \ 1008 "Minimum number of sweeper passes before an nmethod " \ 1009 "can be flushed") \ 1010 range(0, max_intx) \ 1011 \ 1012 develop(bool, StressCodeBuffers, false, \ 1013 "Exercise code buffer expansion and other rare state changes") \ 1014 \ 1015 product(bool, DebugNonSafepoints, trueInDebug, DIAGNOSTIC, \ 1016 "Generate extra debugging information for non-safepoints in " \ 1017 "nmethods") \ 1018 \ 1019 product(bool, PrintVMOptions, false, \ 1020 "Print flags that appeared on the command line") \ 1021 \ 1022 product(bool, IgnoreUnrecognizedVMOptions, false, \ 1023 "Ignore unrecognized VM options") \ 1024 \ 1025 product(bool, PrintCommandLineFlags, false, \ 1026 "Print flags specified on command line or set by ergonomics") \ 1027 \ 1028 product(bool, PrintFlagsInitial, false, \ 1029 "Print all VM flags before argument processing and exit VM") \ 1030 \ 1031 product(bool, PrintFlagsFinal, false, \ 1032 "Print all VM flags after argument and ergonomic processing") \ 1033 \ 1034 develop(bool, PrintFlagsWithComments, false, \ 1035 "Print all VM flags with default values and descriptions and " \ 1036 "exit") \ 1037 \ 1038 product(bool, PrintFlagsRanges, false, \ 1039 "Print VM flags and their ranges") \ 1040 \ 1041 product(bool, SerializeVMOutput, true, DIAGNOSTIC, \ 1042 "Use a mutex to serialize output to tty and LogFile") \ 1043 \ 1044 product(bool, DisplayVMOutput, true, DIAGNOSTIC, \ 1045 "Display all VM output on the tty, independently of LogVMOutput") \ 1046 \ 1047 product(bool, LogVMOutput, false, DIAGNOSTIC, \ 1048 "Save VM output to LogFile") \ 1049 \ 1050 product(ccstr, LogFile, nullptr, DIAGNOSTIC, \ 1051 "If LogVMOutput or LogCompilation is on, save VM output to " \ 1052 "this file [default: ./hotspot_pid%p.log] (%p replaced with pid)")\ 1053 \ 1054 product(ccstr, ErrorFile, nullptr, \ 1055 "If an error occurs, save the error data to this file " \ 1056 "[default: ./hs_err_pid%p.log] (%p replaced with pid)") \ 1057 \ 1058 product(bool, ExtensiveErrorReports, \ 1059 PRODUCT_ONLY(false) NOT_PRODUCT(true), \ 1060 "Error reports are more extensive.") \ 1061 \ 1062 product(bool, DisplayVMOutputToStderr, false, \ 1063 "If DisplayVMOutput is true, display all VM output to stderr") \ 1064 \ 1065 product(bool, DisplayVMOutputToStdout, false, \ 1066 "If DisplayVMOutput is true, display all VM output to stdout") \ 1067 \ 1068 product(bool, ErrorFileToStderr, false, \ 1069 "If true, error data is printed to stderr instead of a file") \ 1070 \ 1071 product(bool, ErrorFileToStdout, false, \ 1072 "If true, error data is printed to stdout instead of a file") \ 1073 \ 1074 develop(bool, VerifyHeavyMonitors, false, \ 1075 "Checks that no stack locking happens when using " \ 1076 "-XX:LockingMode=0 (LM_MONITOR)") \ 1077 \ 1078 product(bool, PrintStringTableStatistics, false, \ 1079 "print statistics about the StringTable and SymbolTable") \ 1080 \ 1081 product(bool, VerifyStringTableAtExit, false, DIAGNOSTIC, \ 1082 "verify StringTable contents at exit") \ 1083 \ 1084 develop(bool, PrintSymbolTableSizeHistogram, false, \ 1085 "print histogram of the symbol table") \ 1086 \ 1087 product(ccstr, AbortVMOnException, nullptr, DIAGNOSTIC, \ 1088 "Call fatal if this exception is thrown. Example: " \ 1089 "java -XX:AbortVMOnException=java.lang.NullPointerException Foo") \ 1090 \ 1091 product(ccstr, AbortVMOnExceptionMessage, nullptr, DIAGNOSTIC, \ 1092 "Call fatal if the exception pointed by AbortVMOnException " \ 1093 "has this message") \ 1094 \ 1095 develop(bool, DebugVtables, false, \ 1096 "add debugging code to vtable dispatch") \ 1097 \ 1098 product(bool, RangeCheckElimination, true, \ 1099 "Eliminate range checks") \ 1100 \ 1101 develop_pd(bool, UncommonNullCast, \ 1102 "track occurrences of null in casts; adjust compiler tactics") \ 1103 \ 1104 develop(bool, TypeProfileCasts, true, \ 1105 "treat casts like calls for purposes of type profiling") \ 1106 \ 1107 develop(bool, TraceLivenessGen, false, \ 1108 "Trace the generation of liveness analysis information") \ 1109 \ 1110 develop(bool, TraceLivenessQuery, false, \ 1111 "Trace queries of liveness analysis information") \ 1112 \ 1113 develop(bool, CollectIndexSetStatistics, false, \ 1114 "Collect information about IndexSets") \ 1115 \ 1116 develop(int, FastAllocateSizeLimit, 128*K, \ 1117 /* Note: This value is zero mod 1<<13 for a cheap sparc set. */ \ 1118 "Inline allocations larger than this in doublewords must go slow")\ 1119 \ 1120 product_pd(bool, CompactStrings, \ 1121 "Enable Strings to use single byte chars in backing store") \ 1122 \ 1123 product_pd(uint, TypeProfileLevel, \ 1124 "=XYZ, with Z: Type profiling of arguments at call; " \ 1125 "Y: Type profiling of return value at call; " \ 1126 "X: Type profiling of parameters to methods; " \ 1127 "X, Y and Z in 0=off ; 1=jsr292 only; 2=all methods") \ 1128 constraint(TypeProfileLevelConstraintFunc, AfterErgo) \ 1129 \ 1130 product(int, TypeProfileArgsLimit, 2, \ 1131 "max number of call arguments to consider for type profiling") \ 1132 range(0, 16) \ 1133 \ 1134 product(int, TypeProfileParmsLimit, 2, \ 1135 "max number of incoming parameters to consider for type profiling"\ 1136 ", -1 for all") \ 1137 range(-1, 64) \ 1138 \ 1139 /* statistics */ \ 1140 develop(bool, CountCompiledCalls, false, \ 1141 "Count method invocations") \ 1142 \ 1143 develop(bool, ICMissHistogram, false, \ 1144 "Produce histogram of IC misses") \ 1145 \ 1146 /* interpreter */ \ 1147 product_pd(bool, RewriteBytecodes, \ 1148 "Allow rewriting of bytecodes (bytecodes are not immutable)") \ 1149 \ 1150 product_pd(bool, RewriteFrequentPairs, \ 1151 "Rewrite frequently used bytecode pairs into a single bytecode") \ 1152 \ 1153 product(bool, PrintInterpreter, false, DIAGNOSTIC, \ 1154 "Print the generated interpreter code") \ 1155 \ 1156 product(bool, UseInterpreter, true, \ 1157 "Use interpreter for non-compiled methods") \ 1158 \ 1159 develop(bool, UseFastSignatureHandlers, true, \ 1160 "Use fast signature handlers for native calls") \ 1161 \ 1162 product(bool, UseLoopCounter, true, \ 1163 "Increment invocation counter on backward branch") \ 1164 \ 1165 product_pd(bool, UseOnStackReplacement, \ 1166 "Use on stack replacement, calls runtime if invoc. counter " \ 1167 "overflows in loop") \ 1168 \ 1169 develop(bool, TraceOnStackReplacement, false, \ 1170 "Trace on stack replacement") \ 1171 \ 1172 product_pd(bool, PreferInterpreterNativeStubs, \ 1173 "Use always interpreter stubs for native methods invoked via " \ 1174 "interpreter") \ 1175 \ 1176 develop(bool, CountBytecodes, false, \ 1177 "Count number of bytecodes executed") \ 1178 \ 1179 develop(bool, PrintBytecodeHistogram, false, \ 1180 "Print histogram of the executed bytecodes") \ 1181 \ 1182 develop(bool, PrintBytecodePairHistogram, false, \ 1183 "Print histogram of the executed bytecode pairs") \ 1184 \ 1185 product(bool, PrintSignatureHandlers, false, DIAGNOSTIC, \ 1186 "Print code generated for native method signature handlers") \ 1187 \ 1188 develop(bool, VerifyOops, false, \ 1189 "Do plausibility checks for oops") \ 1190 \ 1191 develop(bool, CheckUnhandledOops, false, \ 1192 "Check for unhandled oops in VM code") \ 1193 \ 1194 develop(bool, VerifyJNIFields, trueInDebug, \ 1195 "Verify jfieldIDs for instance fields") \ 1196 \ 1197 develop(bool, VerifyFPU, false, \ 1198 "Verify FPU state (check for NaN's, etc.)") \ 1199 \ 1200 develop(bool, VerifyActivationFrameSize, false, \ 1201 "Verify that activation frame didn't become smaller than its " \ 1202 "minimal size") \ 1203 \ 1204 develop(bool, TraceFrequencyInlining, false, \ 1205 "Trace frequency based inlining") \ 1206 \ 1207 develop_pd(bool, InlineIntrinsics, \ 1208 "Use intrinsics in Interpreter that can be statically resolved") \ 1209 \ 1210 product_pd(bool, ProfileInterpreter, \ 1211 "Profile at the bytecode level during interpretation") \ 1212 \ 1213 develop_pd(bool, ProfileTraps, \ 1214 "Profile deoptimization traps at the bytecode level") \ 1215 \ 1216 product(intx, ProfileMaturityPercentage, 20, \ 1217 "number of method invocations/branches (expressed as % of " \ 1218 "CompileThreshold) before using the method's profile") \ 1219 range(0, 100) \ 1220 \ 1221 product(bool, PrintMethodData, false, DIAGNOSTIC, \ 1222 "Print the results of +ProfileInterpreter at end of run") \ 1223 \ 1224 develop(bool, VerifyDataPointer, trueInDebug, \ 1225 "Verify the method data pointer during interpreter profiling") \ 1226 \ 1227 develop(bool, CrashGCForDumpingJavaThread, false, \ 1228 "Manually make GC thread crash then dump java stack trace; " \ 1229 "Test only") \ 1230 \ 1231 /* compilation */ \ 1232 product(bool, UseCompiler, true, \ 1233 "Use Just-In-Time compilation") \ 1234 \ 1235 develop(intx, CounterHalfLifeTime, 30, \ 1236 "Half-life time of invocation counters (in seconds)") \ 1237 \ 1238 product(bool, AlwaysCompileLoopMethods, false, \ 1239 "When using recompilation, never interpret methods " \ 1240 "containing loops") \ 1241 \ 1242 product(int, AllocatePrefetchStyle, 1, \ 1243 "0 = no prefetch, " \ 1244 "1 = generate prefetch instructions for each allocation, " \ 1245 "2 = use TLAB watermark to gate allocation prefetch, " \ 1246 "3 = generate one prefetch instruction per cache line") \ 1247 range(0, 3) \ 1248 \ 1249 product(int, AllocatePrefetchDistance, -1, \ 1250 "Distance to prefetch ahead of allocation pointer. " \ 1251 "-1: use system-specific value (automatically determined") \ 1252 range(-1, 512) \ 1253 \ 1254 product(int, AllocatePrefetchLines, 3, \ 1255 "Number of lines to prefetch ahead of array allocation pointer") \ 1256 range(1, 64) \ 1257 \ 1258 product(int, AllocateInstancePrefetchLines, 1, \ 1259 "Number of lines to prefetch ahead of instance allocation " \ 1260 "pointer") \ 1261 range(1, 64) \ 1262 \ 1263 product(int, AllocatePrefetchStepSize, 16, \ 1264 "Step size in bytes of sequential prefetch instructions") \ 1265 range(1, 512) \ 1266 constraint(AllocatePrefetchStepSizeConstraintFunc,AfterMemoryInit)\ 1267 \ 1268 product(intx, AllocatePrefetchInstr, 0, \ 1269 "Select instruction to prefetch ahead of allocation pointer") \ 1270 constraint(AllocatePrefetchInstrConstraintFunc, AfterMemoryInit) \ 1271 \ 1272 /* deoptimization */ \ 1273 product(bool, TraceDeoptimization, false, DIAGNOSTIC, \ 1274 "Trace deoptimization") \ 1275 \ 1276 develop(bool, PrintDeoptimizationDetails, false, \ 1277 "Print more information about deoptimization") \ 1278 \ 1279 develop(bool, DebugDeoptimization, false, \ 1280 "Tracing various information while debugging deoptimization") \ 1281 \ 1282 product(double, SelfDestructTimer, 0.0, \ 1283 "Will cause VM to terminate after a given time " \ 1284 "(in fractional minutes) " \ 1285 "(0.0 means off)") \ 1286 range(0.0, (double)max_intx) \ 1287 \ 1288 product(int, MaxJavaStackTraceDepth, 1024, \ 1289 "The maximum number of lines in the stack trace for Java " \ 1290 "exceptions (0 means all)") \ 1291 range(0, max_jint/2) \ 1292 \ 1293 /* notice: the max range value here is max_jint, not max_intx */ \ 1294 /* because of overflow issue */ \ 1295 product(intx, GuaranteedSafepointInterval, 0, DIAGNOSTIC, \ 1296 "Guarantee a safepoint (at least) every so many milliseconds " \ 1297 "(0 means none)") \ 1298 range(0, max_jint) \ 1299 \ 1300 product(intx, ServiceThreadCleanupInterval, 1000, DIAGNOSTIC, \ 1301 "Wake the ServiceThread to do periodic cleanup checks every so " \ 1302 "many milliseconds (0 means none)") \ 1303 range(0, max_jint) \ 1304 \ 1305 product(double, SafepointTimeoutDelay, 10000, \ 1306 "Delay in milliseconds for option SafepointTimeout; " \ 1307 "supports sub-millisecond resolution with fractional values.") \ 1308 range(0, max_jlongDouble LP64_ONLY(/MICROUNITS)) \ 1309 \ 1310 product(bool, UseSystemMemoryBarrier, false, \ 1311 "Try to enable system memory barrier if supported by OS") \ 1312 \ 1313 product(intx, NmethodSweepActivity, 4, \ 1314 "Removes cold nmethods from code cache if > 0. Higher values " \ 1315 "result in more aggressive sweeping") \ 1316 range(0, 2000) \ 1317 \ 1318 develop(intx, MallocCatchPtr, -1, \ 1319 "Hit breakpoint when mallocing/freeing this pointer") \ 1320 \ 1321 develop(int, StackPrintLimit, 100, \ 1322 "number of stack frames to print in VM-level stack dump") \ 1323 \ 1324 product(int, ErrorLogPrintCodeLimit, 3, DIAGNOSTIC, \ 1325 "max number of compiled code units to print in error log") \ 1326 range(0, VMError::max_error_log_print_code) \ 1327 \ 1328 develop(int, MaxElementPrintSize, 256, \ 1329 "maximum number of elements to print") \ 1330 \ 1331 develop(intx, MaxSubklassPrintSize, 4, \ 1332 "maximum number of subklasses to print when printing klass") \ 1333 \ 1334 develop(intx, MaxForceInlineLevel, 100, \ 1335 "maximum number of nested calls that are forced for inlining " \ 1336 "(using CompileCommand or marked w/ @ForceInline)") \ 1337 range(0, max_jint) \ 1338 \ 1339 develop(intx, MethodHistogramCutoff, 100, \ 1340 "The cutoff value for method invocation histogram (+CountCalls)") \ 1341 \ 1342 develop(intx, DeoptimizeALotInterval, 5, \ 1343 "Number of exits until DeoptimizeALot kicks in") \ 1344 \ 1345 develop(intx, ZombieALotInterval, 5, \ 1346 "Number of exits until ZombieALot kicks in") \ 1347 \ 1348 product(ccstr, MallocLimit, nullptr, DIAGNOSTIC, \ 1349 "Limit malloc allocation size from VM. Reaching a limit will " \ 1350 "trigger an action (see flag). This feature requires " \ 1351 "NativeMemoryTracking=summary or NativeMemoryTracking=detail." \ 1352 "Usage:" \ 1353 "\"-XX:MallocLimit=<size>[:<flag>]\" sets a total limit." \ 1354 "\"-XX:MallocLimit=<category>:<size>[:<flag>][,<category>:<size>[:<flag>] ...]\"" \ 1355 "sets one or more category-specific limits." \ 1356 "<flag> defines the action upon reaching the limit:" \ 1357 "\"fatal\": end VM with a fatal error at the allocation site" \ 1358 "\"oom\" : will mimic a native OOM" \ 1359 "If <flag> is omitted, \"fatal\" is the default." \ 1360 "Examples:\n" \ 1361 "-XX:MallocLimit=2g" \ 1362 "-XX:MallocLimit=2g:oom" \ 1363 "-XX:MallocLimit=compiler:200m:oom,code:100m") \ 1364 \ 1365 product(intx, TypeProfileWidth, 2, \ 1366 "Number of receiver types to record in call/cast profile") \ 1367 range(0, 8) \ 1368 \ 1369 develop(intx, BciProfileWidth, 2, \ 1370 "Number of return bci's to record in ret profile") \ 1371 \ 1372 product(intx, PerMethodRecompilationCutoff, 400, \ 1373 "After recompiling N times, stay in the interpreter (-1=>'Inf')") \ 1374 range(-1, max_intx) \ 1375 \ 1376 product(intx, PerBytecodeRecompilationCutoff, 200, \ 1377 "Per-BCI limit on repeated recompilation (-1=>'Inf')") \ 1378 range(-1, max_intx) \ 1379 \ 1380 product(intx, PerMethodTrapLimit, 100, \ 1381 "Limit on traps (of one kind) in a method (includes inlines)") \ 1382 range(0, max_jint) \ 1383 \ 1384 product(intx, PerMethodSpecTrapLimit, 5000, EXPERIMENTAL, \ 1385 "Limit on speculative traps (of one kind) in a method " \ 1386 "(includes inlines)") \ 1387 range(0, max_jint) \ 1388 \ 1389 product(intx, PerBytecodeTrapLimit, 4, \ 1390 "Limit on traps (of one kind) at a particular BCI") \ 1391 range(0, max_jint) \ 1392 \ 1393 product(int, SpecTrapLimitExtraEntries, 3, EXPERIMENTAL, \ 1394 "Extra method data trap entries for speculation") \ 1395 \ 1396 product(double, InlineFrequencyRatio, 0.25, DIAGNOSTIC, \ 1397 "Ratio of call site execution to caller method invocation") \ 1398 \ 1399 product(double, MinInlineFrequencyRatio, 0.0085, DIAGNOSTIC, \ 1400 "Minimum ratio of call site execution to caller method" \ 1401 "invocation to be considered for inlining") \ 1402 \ 1403 develop(intx, InlineThrowCount, 50, \ 1404 "Force inlining of interpreted methods that throw this often") \ 1405 range(0, max_jint) \ 1406 \ 1407 develop(intx, InlineThrowMaxSize, 200, \ 1408 "Force inlining of throwing methods smaller than this") \ 1409 range(0, max_jint) \ 1410 \ 1411 product(size_t, MetaspaceSize, NOT_LP64(16 * M) LP64_ONLY(21 * M), \ 1412 "Initial threshold (in bytes) at which a garbage collection " \ 1413 "is done to reduce Metaspace usage") \ 1414 constraint(MetaspaceSizeConstraintFunc,AfterErgo) \ 1415 \ 1416 product(size_t, MaxMetaspaceSize, max_uintx, \ 1417 "Maximum size of Metaspaces (in bytes)") \ 1418 constraint(MaxMetaspaceSizeConstraintFunc,AfterErgo) \ 1419 \ 1420 product(size_t, CompressedClassSpaceSize, 1*G, \ 1421 "Maximum size of class area in Metaspace when compressed " \ 1422 "class pointers are used") \ 1423 range(1*M, LP64_ONLY(4*G) NOT_LP64(max_uintx)) \ 1424 \ 1425 develop(size_t, CompressedClassSpaceBaseAddress, 0, \ 1426 "Force the class space to be allocated at this address or " \ 1427 "fails VM initialization (requires -Xshare=off.") \ 1428 \ 1429 develop(bool, RandomizeClassSpaceLocation, true, \ 1430 "Randomize location of class space.") \ 1431 \ 1432 product(bool, PrintMetaspaceStatisticsAtExit, false, DIAGNOSTIC, \ 1433 "Print metaspace statistics upon VM exit.") \ 1434 \ 1435 develop(bool, MetaspaceGuardAllocations, false, \ 1436 "Metapace allocations are guarded.") \ 1437 \ 1438 product(uintx, MinHeapFreeRatio, 40, MANAGEABLE, \ 1439 "The minimum percentage of heap free after GC to avoid expansion."\ 1440 " For most GCs this applies to the old generation. In G1 and" \ 1441 " ParallelGC it applies to the whole heap.") \ 1442 range(0, 100) \ 1443 constraint(MinHeapFreeRatioConstraintFunc,AfterErgo) \ 1444 \ 1445 product(uintx, MaxHeapFreeRatio, 70, MANAGEABLE, \ 1446 "The maximum percentage of heap free after GC to avoid shrinking."\ 1447 " For most GCs this applies to the old generation. In G1 and" \ 1448 " ParallelGC it applies to the whole heap.") \ 1449 range(0, 100) \ 1450 constraint(MaxHeapFreeRatioConstraintFunc,AfterErgo) \ 1451 \ 1452 product(intx, SoftRefLRUPolicyMSPerMB, 1000, \ 1453 "Number of milliseconds per MB of free space in the heap") \ 1454 range(0, max_intx) \ 1455 constraint(SoftRefLRUPolicyMSPerMBConstraintFunc,AfterMemoryInit) \ 1456 \ 1457 product(size_t, MinHeapDeltaBytes, ScaleForWordSize(128*K), \ 1458 "The minimum change in heap space due to GC (in bytes)") \ 1459 range(0, max_uintx) \ 1460 \ 1461 product(size_t, MinMetaspaceExpansion, ScaleForWordSize(256*K), \ 1462 "The minimum expansion of Metaspace (in bytes)") \ 1463 range(0, max_uintx) \ 1464 \ 1465 product(uint, MaxMetaspaceFreeRatio, 70, \ 1466 "The maximum percentage of Metaspace free after GC to avoid " \ 1467 "shrinking") \ 1468 range(0, 100) \ 1469 constraint(MaxMetaspaceFreeRatioConstraintFunc,AfterErgo) \ 1470 \ 1471 product(uint, MinMetaspaceFreeRatio, 40, \ 1472 "The minimum percentage of Metaspace free after GC to avoid " \ 1473 "expansion") \ 1474 range(0, 99) \ 1475 constraint(MinMetaspaceFreeRatioConstraintFunc,AfterErgo) \ 1476 \ 1477 product(size_t, MaxMetaspaceExpansion, ScaleForWordSize(4*M), \ 1478 "The maximum expansion of Metaspace without full GC (in bytes)") \ 1479 range(0, max_uintx) \ 1480 \ 1481 /* stack parameters */ \ 1482 product_pd(intx, StackYellowPages, \ 1483 "Number of yellow zone (recoverable overflows) pages of size " \ 1484 "4KB. If pages are bigger yellow zone is aligned up.") \ 1485 range(MIN_STACK_YELLOW_PAGES, (DEFAULT_STACK_YELLOW_PAGES+5)) \ 1486 \ 1487 product_pd(intx, StackRedPages, \ 1488 "Number of red zone (unrecoverable overflows) pages of size " \ 1489 "4KB. If pages are bigger red zone is aligned up.") \ 1490 range(MIN_STACK_RED_PAGES, (DEFAULT_STACK_RED_PAGES+2)) \ 1491 \ 1492 product_pd(intx, StackReservedPages, \ 1493 "Number of reserved zone (reserved to annotated methods) pages" \ 1494 " of size 4KB. If pages are bigger reserved zone is aligned up.") \ 1495 range(MIN_STACK_RESERVED_PAGES, (DEFAULT_STACK_RESERVED_PAGES+10))\ 1496 \ 1497 product(bool, RestrictReservedStack, true, \ 1498 "Restrict @ReservedStackAccess to trusted classes") \ 1499 \ 1500 /* greater stack shadow pages can't generate instruction to bang stack */ \ 1501 product_pd(intx, StackShadowPages, \ 1502 "Number of shadow zone (for overflow checking) pages of size " \ 1503 "4KB. If pages are bigger shadow zone is aligned up. " \ 1504 "This should exceed the depth of the VM and native call stack.") \ 1505 range(MIN_STACK_SHADOW_PAGES, (DEFAULT_STACK_SHADOW_PAGES+30)) \ 1506 \ 1507 product_pd(intx, ThreadStackSize, \ 1508 "Thread Stack Size (in Kbytes)") \ 1509 range(0, 1 * M) \ 1510 \ 1511 product_pd(intx, VMThreadStackSize, \ 1512 "Non-Java Thread Stack Size (in Kbytes)") \ 1513 range(0, max_intx/(1 * K)) \ 1514 \ 1515 product_pd(intx, CompilerThreadStackSize, \ 1516 "Compiler Thread Stack Size (in Kbytes)") \ 1517 range(0, max_intx/(1 * K)) \ 1518 \ 1519 develop_pd(size_t, JVMInvokeMethodSlack, \ 1520 "Stack space (bytes) required for JVM_InvokeMethod to complete") \ 1521 \ 1522 /* code cache parameters */ \ 1523 product_pd(uintx, CodeCacheSegmentSize, EXPERIMENTAL, \ 1524 "Code cache segment size (in bytes) - smallest unit of " \ 1525 "allocation") \ 1526 range(1, 1024) \ 1527 constraint(CodeCacheSegmentSizeConstraintFunc, AfterErgo) \ 1528 \ 1529 product_pd(intx, CodeEntryAlignment, EXPERIMENTAL, \ 1530 "Code entry alignment for generated code (in bytes)") \ 1531 constraint(CodeEntryAlignmentConstraintFunc, AfterErgo) \ 1532 \ 1533 product_pd(intx, OptoLoopAlignment, \ 1534 "Align inner loops to zero relative to this modulus") \ 1535 range(1, 128) \ 1536 constraint(OptoLoopAlignmentConstraintFunc, AfterErgo) \ 1537 \ 1538 product_pd(uintx, InitialCodeCacheSize, \ 1539 "Initial code cache size (in bytes)") \ 1540 constraint(VMPageSizeConstraintFunc, AtParse) \ 1541 \ 1542 develop_pd(uintx, CodeCacheMinimumUseSpace, \ 1543 "Minimum code cache size (in bytes) required to start VM.") \ 1544 range(0, max_uintx) \ 1545 \ 1546 product(bool, SegmentedCodeCache, false, \ 1547 "Use a segmented code cache") \ 1548 \ 1549 product_pd(uintx, ReservedCodeCacheSize, \ 1550 "Reserved code cache size (in bytes) - maximum code cache size") \ 1551 constraint(VMPageSizeConstraintFunc, AtParse) \ 1552 \ 1553 product_pd(uintx, NonProfiledCodeHeapSize, \ 1554 "Size of code heap with non-profiled methods (in bytes)") \ 1555 range(0, max_uintx) \ 1556 \ 1557 product_pd(uintx, ProfiledCodeHeapSize, \ 1558 "Size of code heap with profiled methods (in bytes)") \ 1559 range(0, max_uintx) \ 1560 \ 1561 product_pd(uintx, NonNMethodCodeHeapSize, \ 1562 "Size of code heap with non-nmethods (in bytes)") \ 1563 constraint(VMPageSizeConstraintFunc, AtParse) \ 1564 \ 1565 product_pd(uintx, CodeCacheExpansionSize, \ 1566 "Code cache expansion size (in bytes)") \ 1567 range(32*K, max_uintx) \ 1568 \ 1569 product_pd(uintx, CodeCacheMinBlockLength, DIAGNOSTIC, \ 1570 "Minimum number of segments in a code cache block") \ 1571 range(1, 100) \ 1572 \ 1573 develop(bool, ExitOnFullCodeCache, false, \ 1574 "Exit the VM if we fill the code cache") \ 1575 \ 1576 product(bool, UseCodeCacheFlushing, true, \ 1577 "Remove cold/old nmethods from the code cache") \ 1578 \ 1579 product(double, SweeperThreshold, 15.0, \ 1580 "Threshold when a code cache unloading GC is invoked." \ 1581 "Value is percentage of ReservedCodeCacheSize.") \ 1582 range(0.0, 100.0) \ 1583 \ 1584 product(uintx, StartAggressiveSweepingAt, 10, \ 1585 "Start aggressive sweeping if X[%] of the code cache is free." \ 1586 "Segmented code cache: X[%] of the non-profiled heap." \ 1587 "Non-segmented code cache: X[%] of the total code cache") \ 1588 range(0, 100) \ 1589 \ 1590 /* interpreter debugging */ \ 1591 develop(intx, BinarySwitchThreshold, 5, \ 1592 "Minimal number of lookupswitch entries for rewriting to binary " \ 1593 "switch") \ 1594 \ 1595 develop(intx, StopInterpreterAt, 0, \ 1596 "Stop interpreter execution at specified bytecode number") \ 1597 \ 1598 develop(intx, TraceBytecodesAt, 0, \ 1599 "Trace bytecodes starting with specified bytecode number") \ 1600 \ 1601 develop(intx, TraceBytecodesStopAt, 0, \ 1602 "Stop bytecode tracing at the specified bytecode number") \ 1603 \ 1604 /* Priorities */ \ 1605 product_pd(bool, UseThreadPriorities, "Use native thread priorities") \ 1606 \ 1607 product(int, ThreadPriorityPolicy, 0, \ 1608 "0 : Normal. "\ 1609 " VM chooses priorities that are appropriate for normal "\ 1610 " applications. "\ 1611 " On Windows applications are allowed to use higher native "\ 1612 " priorities. However, with ThreadPriorityPolicy=0, VM will "\ 1613 " not use the highest possible native priority, "\ 1614 " THREAD_PRIORITY_TIME_CRITICAL, as it may interfere with "\ 1615 " system threads. On Linux thread priorities are ignored "\ 1616 " because the OS does not support static priority in "\ 1617 " SCHED_OTHER scheduling class which is the only choice for "\ 1618 " non-root, non-realtime applications. "\ 1619 "1 : Aggressive. "\ 1620 " Java thread priorities map over to the entire range of "\ 1621 " native thread priorities. Higher Java thread priorities map "\ 1622 " to higher native thread priorities. This policy should be "\ 1623 " used with care, as sometimes it can cause performance "\ 1624 " degradation in the application and/or the entire system. On "\ 1625 " Linux/BSD/macOS this policy requires root privilege or an "\ 1626 " extended capability.") \ 1627 range(0, 1) \ 1628 \ 1629 product(bool, ThreadPriorityVerbose, false, \ 1630 "Print priority changes") \ 1631 \ 1632 product(int, CompilerThreadPriority, -1, \ 1633 "The native priority at which compiler threads should run " \ 1634 "(-1 means no change)") \ 1635 range(min_jint, max_jint) \ 1636 \ 1637 product(int, VMThreadPriority, -1, \ 1638 "The native priority at which the VM thread should run " \ 1639 "(-1 means no change)") \ 1640 range(-1, 127) \ 1641 \ 1642 product(int, JavaPriority1_To_OSPriority, -1, \ 1643 "Map Java priorities to OS priorities") \ 1644 range(-1, 127) \ 1645 \ 1646 product(int, JavaPriority2_To_OSPriority, -1, \ 1647 "Map Java priorities to OS priorities") \ 1648 range(-1, 127) \ 1649 \ 1650 product(int, JavaPriority3_To_OSPriority, -1, \ 1651 "Map Java priorities to OS priorities") \ 1652 range(-1, 127) \ 1653 \ 1654 product(int, JavaPriority4_To_OSPriority, -1, \ 1655 "Map Java priorities to OS priorities") \ 1656 range(-1, 127) \ 1657 \ 1658 product(int, JavaPriority5_To_OSPriority, -1, \ 1659 "Map Java priorities to OS priorities") \ 1660 range(-1, 127) \ 1661 \ 1662 product(int, JavaPriority6_To_OSPriority, -1, \ 1663 "Map Java priorities to OS priorities") \ 1664 range(-1, 127) \ 1665 \ 1666 product(int, JavaPriority7_To_OSPriority, -1, \ 1667 "Map Java priorities to OS priorities") \ 1668 range(-1, 127) \ 1669 \ 1670 product(int, JavaPriority8_To_OSPriority, -1, \ 1671 "Map Java priorities to OS priorities") \ 1672 range(-1, 127) \ 1673 \ 1674 product(int, JavaPriority9_To_OSPriority, -1, \ 1675 "Map Java priorities to OS priorities") \ 1676 range(-1, 127) \ 1677 \ 1678 product(int, JavaPriority10_To_OSPriority,-1, \ 1679 "Map Java priorities to OS priorities") \ 1680 range(-1, 127) \ 1681 \ 1682 product(bool, UseCriticalJavaThreadPriority, false, EXPERIMENTAL, \ 1683 "Java thread priority 10 maps to critical scheduling priority") \ 1684 \ 1685 product(bool, UseCriticalCompilerThreadPriority, false, EXPERIMENTAL, \ 1686 "Compiler thread(s) run at critical scheduling priority") \ 1687 \ 1688 develop(intx, NewCodeParameter, 0, \ 1689 "Testing Only: Create a dedicated integer parameter before " \ 1690 "putback") \ 1691 \ 1692 /* new oopmap storage allocation */ \ 1693 develop(intx, MinOopMapAllocation, 8, \ 1694 "Minimum number of OopMap entries in an OopMapSet") \ 1695 \ 1696 /* recompilation */ \ 1697 product_pd(intx, CompileThreshold, \ 1698 "number of interpreted method invocations before (re-)compiling") \ 1699 constraint(CompileThresholdConstraintFunc, AfterErgo) \ 1700 \ 1701 product_pd(bool, TieredCompilation, \ 1702 "Enable tiered compilation") \ 1703 \ 1704 /* Properties for Java libraries */ \ 1705 \ 1706 product(uint64_t, MaxDirectMemorySize, 0, \ 1707 "Maximum total size of NIO direct-buffer allocations. " \ 1708 "Ignored if not explicitly set.") \ 1709 range(0, max_jlong) \ 1710 \ 1711 /* Flags used for temporary code during development */ \ 1712 \ 1713 product(bool, UseNewCode, false, DIAGNOSTIC, \ 1714 "Testing Only: Use the new version while testing") \ 1715 \ 1716 product(bool, UseNewCode2, false, DIAGNOSTIC, \ 1717 "Testing Only: Use the new version while testing") \ 1718 \ 1719 product(bool, UseNewCode3, false, DIAGNOSTIC, \ 1720 "Testing Only: Use the new version while testing") \ 1721 \ 1722 develop(bool, UseDebuggerErgo, false, \ 1723 "Debugging Only: Adjust the VM to be more debugger-friendly. " \ 1724 "Turns on the other UseDebuggerErgo* flags") \ 1725 \ 1726 develop(bool, UseDebuggerErgo1, false, \ 1727 "Debugging Only: Enable workarounds for debugger induced " \ 1728 "os::processor_id() >= os::processor_count() problems") \ 1729 \ 1730 develop(bool, UseDebuggerErgo2, false, \ 1731 "Debugging Only: Limit the number of spawned JVM threads") \ 1732 \ 1733 develop(bool, EnableJVMTIStackDepthAsserts, true, \ 1734 "Enable JVMTI asserts related to stack depth checks") \ 1735 \ 1736 /* flags for performance data collection */ \ 1737 \ 1738 product(bool, UsePerfData, true, \ 1739 "Flag to disable jvmstat instrumentation for performance testing "\ 1740 "and problem isolation purposes") \ 1741 \ 1742 product(bool, PerfDataSaveToFile, false, \ 1743 "Save PerfData memory to hsperfdata_<pid> file on exit") \ 1744 \ 1745 product(ccstr, PerfDataSaveFile, nullptr, \ 1746 "Save PerfData memory to the specified absolute pathname. " \ 1747 "The string %p in the file name (if present) " \ 1748 "will be replaced by pid") \ 1749 \ 1750 product(int, PerfDataSamplingInterval, 50, \ 1751 "Data sampling interval (in milliseconds)") \ 1752 range(PeriodicTask::min_interval, max_jint) \ 1753 constraint(PerfDataSamplingIntervalFunc, AfterErgo) \ 1754 \ 1755 product(bool, PerfDisableSharedMem, false, \ 1756 "Store performance data in standard memory") \ 1757 \ 1758 product(int, PerfDataMemorySize, 32*K, \ 1759 "Size of performance data memory region. Will be rounded " \ 1760 "up to a multiple of the native os page size.") \ 1761 range(128, 32*64*K) \ 1762 \ 1763 product(int, PerfMaxStringConstLength, 1024, \ 1764 "Maximum PerfStringConstant string length before truncation") \ 1765 range(32, 32*K) \ 1766 \ 1767 product(bool, PerfAllowAtExitRegistration, false, \ 1768 "Allow registration of atexit() methods") \ 1769 \ 1770 product(bool, PerfBypassFileSystemCheck, false, \ 1771 "Bypass Win32 file system criteria checks (Windows Only)") \ 1772 \ 1773 product(int, UnguardOnExecutionViolation, 0, \ 1774 "Unguard page and retry on no-execute fault (Win32 only) " \ 1775 "0=off, 1=conservative, 2=aggressive") \ 1776 range(0, 2) \ 1777 \ 1778 /* Serviceability Support */ \ 1779 \ 1780 product(bool, ManagementServer, false, \ 1781 "Create JMX Management Server") \ 1782 \ 1783 product(bool, DisableAttachMechanism, false, \ 1784 "Disable mechanism that allows tools to attach to this VM") \ 1785 \ 1786 product(bool, StartAttachListener, false, \ 1787 "Always start Attach Listener at VM startup") \ 1788 \ 1789 product(bool, EnableDynamicAgentLoading, true, \ 1790 "Allow tools to load agents with the attach mechanism") \ 1791 \ 1792 product(bool, PrintConcurrentLocks, false, MANAGEABLE, \ 1793 "Print java.util.concurrent locks in thread dump") \ 1794 \ 1795 product(bool, PrintMethodHandleStubs, false, DIAGNOSTIC, \ 1796 "Print generated stub code for method handles") \ 1797 \ 1798 product(bool, VerifyMethodHandles, trueInDebug, DIAGNOSTIC, \ 1799 "perform extra checks when constructing method handles") \ 1800 \ 1801 product(bool, ShowHiddenFrames, false, DIAGNOSTIC, \ 1802 "show method handle implementation frames (usually hidden)") \ 1803 \ 1804 product(bool, ShowCarrierFrames, false, DIAGNOSTIC, \ 1805 "show virtual threads' carrier frames in exceptions") \ 1806 \ 1807 product(bool, TrustFinalNonStaticFields, false, EXPERIMENTAL, \ 1808 "trust final non-static declarations for constant folding") \ 1809 \ 1810 product(bool, FoldStableValues, true, DIAGNOSTIC, \ 1811 "Optimize loads from stable fields (marked w/ @Stable)") \ 1812 \ 1813 product(int, UseBootstrapCallInfo, 1, DIAGNOSTIC, \ 1814 "0: when resolving InDy or ConDy, force all BSM arguments to be " \ 1815 "resolved before the bootstrap method is called; 1: when a BSM " \ 1816 "that may accept a BootstrapCallInfo is detected, use that API " \ 1817 "to pass BSM arguments, which allows the BSM to delay their " \ 1818 "resolution; 2+: stress test the BCI API by calling more BSMs " \ 1819 "via that API, instead of with the eagerly-resolved array.") \ 1820 \ 1821 product(bool, PauseAtStartup, false, DIAGNOSTIC, \ 1822 "Causes the VM to pause at startup time and wait for the pause " \ 1823 "file to be removed (default: ./vm.paused.<pid>)") \ 1824 \ 1825 product(ccstr, PauseAtStartupFile, nullptr, DIAGNOSTIC, \ 1826 "The file to create and for whose removal to await when pausing " \ 1827 "at startup. (default: ./vm.paused.<pid>)") \ 1828 \ 1829 product(bool, PauseAtExit, false, DIAGNOSTIC, \ 1830 "Pause and wait for keypress on exit if a debugger is attached") \ 1831 \ 1832 product(bool, DTraceMethodProbes, false, \ 1833 "Enable dtrace tool probes for method-entry and method-exit") \ 1834 \ 1835 product(bool, DTraceAllocProbes, false, \ 1836 "Enable dtrace tool probes for object allocation") \ 1837 \ 1838 product(bool, DTraceMonitorProbes, false, \ 1839 "Enable dtrace tool probes for monitor events") \ 1840 \ 1841 product(bool, RelaxAccessControlCheck, false, \ 1842 "Relax the access control checks in the verifier") \ 1843 \ 1844 product(uintx, StringTableSize, defaultStringTableSize, \ 1845 "Number of buckets in the interned String table " \ 1846 "(will be rounded to nearest higher power of 2)") \ 1847 range(minimumStringTableSize, 16777216ul /* 2^24 */) \ 1848 \ 1849 product(uintx, SymbolTableSize, defaultSymbolTableSize, EXPERIMENTAL, \ 1850 "Number of buckets in the JVM internal Symbol table") \ 1851 range(minimumSymbolTableSize, 16777216ul /* 2^24 */) \ 1852 \ 1853 product(bool, UseStringDeduplication, false, \ 1854 "Use string deduplication") \ 1855 \ 1856 product(uint, StringDeduplicationAgeThreshold, 3, \ 1857 "A string must reach this age (or be promoted to an old region) " \ 1858 "to be considered for deduplication") \ 1859 range(1, markWord::max_age) \ 1860 \ 1861 product(size_t, StringDeduplicationInitialTableSize, 500, EXPERIMENTAL, \ 1862 "Approximate initial number of buckets in the table") \ 1863 range(1, 1 * G) \ 1864 \ 1865 product(double, StringDeduplicationGrowTableLoad, 14.0, EXPERIMENTAL, \ 1866 "Entries per bucket above which the table should be expanded") \ 1867 range(0.1, 1000.0) \ 1868 \ 1869 product(double, StringDeduplicationShrinkTableLoad, 1.0, EXPERIMENTAL, \ 1870 "Entries per bucket below which the table should be shrunk") \ 1871 range(0.01, 100.0) \ 1872 \ 1873 product(double, StringDeduplicationTargetTableLoad, 7.0, EXPERIMENTAL, \ 1874 "Desired entries per bucket when resizing the table") \ 1875 range(0.01, 1000.0) \ 1876 \ 1877 product(size_t, StringDeduplicationCleanupDeadMinimum, 100, EXPERIMENTAL, \ 1878 "Minimum number of dead table entries for cleaning the table") \ 1879 \ 1880 product(int, StringDeduplicationCleanupDeadPercent, 5, EXPERIMENTAL, \ 1881 "Minimum percentage of dead table entries for cleaning the table") \ 1882 range(1, 100) \ 1883 \ 1884 product(bool, StringDeduplicationResizeALot, false, DIAGNOSTIC, \ 1885 "Force more frequent table resizing") \ 1886 \ 1887 product(uint64_t, StringDeduplicationHashSeed, 0, DIAGNOSTIC, \ 1888 "Seed for the table hashing function; 0 requests computed seed") \ 1889 \ 1890 product(bool, WhiteBoxAPI, false, DIAGNOSTIC, \ 1891 "Enable internal testing APIs") \ 1892 \ 1893 product(bool, AlwaysAtomicAccesses, false, EXPERIMENTAL, \ 1894 "Accesses to all variables should always be atomic") \ 1895 \ 1896 product(bool, UseUnalignedAccesses, false, DIAGNOSTIC, \ 1897 "Use unaligned memory accesses in Unsafe") \ 1898 \ 1899 product_pd(bool, PreserveFramePointer, \ 1900 "Use the FP register for holding the frame pointer " \ 1901 "and not as a general purpose register.") \ 1902 \ 1903 product(size_t, AsyncLogBufferSize, 2*M, \ 1904 "Memory budget (in bytes) for the buffer of Asynchronous " \ 1905 "Logging (-Xlog:async).") \ 1906 range(100*K, 50*M) \ 1907 \ 1908 product(bool, CheckIntrinsics, true, DIAGNOSTIC, \ 1909 "When a class C is loaded, check that " \ 1910 "(1) all intrinsics defined by the VM for class C are present "\ 1911 "in the loaded class file and are marked with the " \ 1912 "@IntrinsicCandidate annotation, that " \ 1913 "(2) there is an intrinsic registered for all loaded methods " \ 1914 "that are annotated with the @IntrinsicCandidate annotation, " \ 1915 "and that " \ 1916 "(3) no orphan methods exist for class C (i.e., methods for " \ 1917 "which the VM declares an intrinsic but that are not declared "\ 1918 "in the loaded class C. " \ 1919 "Check (3) is available only in debug builds.") \ 1920 \ 1921 product_pd(intx, InitArrayShortSize, DIAGNOSTIC, \ 1922 "Threshold small size (in bytes) for clearing arrays. " \ 1923 "Anything this size or smaller may get converted to discrete " \ 1924 "scalar stores.") \ 1925 range(0, max_intx) \ 1926 constraint(InitArrayShortSizeConstraintFunc, AfterErgo) \ 1927 \ 1928 product(ccstr, AllocateHeapAt, nullptr, \ 1929 "Path to the directory where a temporary file will be created " \ 1930 "to use as the backing store for Java Heap.") \ 1931 \ 1932 product_pd(bool, VMContinuations, EXPERIMENTAL, \ 1933 "Enable VM continuations support") \ 1934 \ 1935 develop(bool, LoomDeoptAfterThaw, false, \ 1936 "Deopt stack after thaw") \ 1937 \ 1938 develop(bool, LoomVerifyAfterThaw, false, \ 1939 "Verify stack after thaw") \ 1940 \ 1941 develop(bool, VerifyContinuations, false, \ 1942 "Verify continuation consistency") \ 1943 \ 1944 develop(bool, UseContinuationFastPath, true, \ 1945 "Use fast-path frame walking in continuations") \ 1946 \ 1947 develop(int, VerifyMetaspaceInterval, DEBUG_ONLY(500) NOT_DEBUG(0), \ 1948 "Run periodic metaspace verifications (0 - none, " \ 1949 "1 - always, >1 every nth interval)") \ 1950 \ 1951 product(bool, ShowRegistersOnAssert, true, DIAGNOSTIC, \ 1952 "On internal errors, include registers in error report.") \ 1953 \ 1954 product(bool, UseSwitchProfiling, true, DIAGNOSTIC, \ 1955 "leverage profiling for table/lookup switch") \ 1956 \ 1957 develop(bool, TraceMemoryWriteback, false, \ 1958 "Trace memory writeback operations") \ 1959 \ 1960 JFR_ONLY(product(bool, FlightRecorder, false, \ 1961 "(Deprecated) Enable Flight Recorder")) \ 1962 \ 1963 JFR_ONLY(product(ccstr, FlightRecorderOptions, nullptr, \ 1964 "Flight Recorder options")) \ 1965 \ 1966 JFR_ONLY(product(ccstr, StartFlightRecording, nullptr, \ 1967 "Start flight recording with options")) \ 1968 \ 1969 product(bool, UseFastUnorderedTimeStamps, false, EXPERIMENTAL, \ 1970 "Use platform unstable time where supported for timestamps only") \ 1971 \ 1972 product(bool, EnableValhalla, true, \ 1973 "Enable experimental Valhalla features") \ 1974 \ 1975 product_pd(bool, InlineTypePassFieldsAsArgs, \ 1976 "Pass each inline type field as an argument at calls") \ 1977 \ 1978 product_pd(bool, InlineTypeReturnedAsFields, \ 1979 "Return fields instead of an inline type reference") \ 1980 \ 1981 develop(bool, StressCallingConvention, false, \ 1982 "Stress the scalarized calling convention.") \ 1983 \ 1984 product(ccstrlist, ForceNonTearable, "", DIAGNOSTIC, \ 1985 "List of inline classes which are forced to be atomic " \ 1986 "(whitespace and commas separate names, " \ 1987 "and leading and trailing stars '*' are wildcards)") \ 1988 \ 1989 product(bool, UseEmptySlotsInSupers, true, \ 1990 "(Deprecated) Allow allocating fields in empty slots of " \ 1991 "super-classes") \ 1992 \ 1993 product(bool, DeoptimizeNMethodBarriersALot, false, DIAGNOSTIC, \ 1994 "Make nmethod barriers deoptimise a lot.") \ 1995 \ 1996 develop(bool, VerifyCrossModifyFence, \ 1997 false AARCH64_ONLY(DEBUG_ONLY(||true)), \ 1998 "Mark all threads after a safepoint, and clear on a modify " \ 1999 "fence. Add cleanliness checks.") \ 2000 \ 2001 product(int, LockingMode, LM_LIGHTWEIGHT, \ 2002 "Select locking mode: " \ 2003 "0: monitors only (LM_MONITOR), " \ 2004 "1: monitors & legacy stack-locking (LM_LEGACY), " \ 2005 "2: monitors & new lightweight locking (LM_LIGHTWEIGHT, default)") \ 2006 range(0, 2) \ 2007 \ 2008 product(uint, TrimNativeHeapInterval, 0, \ 2009 "Interval, in ms, at which the JVM will trim the native heap if " \ 2010 "the platform supports that. Lower values will reclaim memory " \ 2011 "more eagerly at the cost of higher overhead. A value of 0 " \ 2012 "(default) disables native heap trimming.") \ 2013 range(0, UINT_MAX) \ 2014 \ 2015 develop(bool, SimulateFullAddressSpace, false, \ 2016 "Simulates a very populated, fragmented address space; no " \ 2017 "targeted reservations will succeed.") \ 2018 \ 2019 product(bool, ProfileExceptionHandlers, true, \ 2020 "Profile exception handlers") \ 2021 \ 2022 product(bool, AlwaysRecordEvolDependencies, true, EXPERIMENTAL, \ 2023 "Unconditionally record nmethod dependencies on class " \ 2024 "rewriting/transformation independently of the JVMTI " \ 2025 "can_{retransform/redefine}_classes capabilities.") \ 2026 \ 2027 product(bool, UseSecondarySupersCache, true, DIAGNOSTIC, \ 2028 "Use secondary supers cache during subtype checks.") \ 2029 \ 2030 product(bool, UseSecondarySupersTable, false, DIAGNOSTIC, \ 2031 "Use hash table to lookup secondary supers.") \ 2032 \ 2033 product(bool, VerifySecondarySupers, false, DIAGNOSTIC, \ 2034 "Check that linear and hashed secondary lookups return the same result.") \ 2035 \ 2036 product(bool, StressSecondarySupers, false, DIAGNOSTIC, \ 2037 "Use a terrible hash function in order to generate many collisions.") \ 2038 2039 // end of RUNTIME_FLAGS 2040 2041 DECLARE_FLAGS(LP64_RUNTIME_FLAGS) 2042 DECLARE_ARCH_FLAGS(ARCH_FLAGS) 2043 DECLARE_FLAGS(RUNTIME_FLAGS) 2044 DECLARE_FLAGS(RUNTIME_OS_FLAGS) 2045 2046 #endif // SHARE_RUNTIME_GLOBALS_HPP