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