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, HeapDumpPath, HeapDumpGzipLevel)")\ 546 \ 547 product(bool, HeapDumpAfterFullGC, false, MANAGEABLE, \ 548 "Dump heap to file after any major stop-the-world GC " \ 549 "(also see FullGCHeapDumpLimit, HeapDumpPath, HeapDumpGzipLevel)")\ 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 "(also see HeapDumpPath, HeapDumpGzipLevel)") \ 560 \ 561 product(ccstr, HeapDumpPath, nullptr, MANAGEABLE, \ 562 "When HeapDumpOnOutOfMemoryError, HeapDumpBeforeFullGC " \ 563 "or HeapDumpAfterFullGC is on, the path (filename or " \ 564 "directory) of the dump file (defaults to java_pid<pid>.hprof " \ 565 "in the working directory)") \ 566 \ 567 product(int, HeapDumpGzipLevel, 0, MANAGEABLE, \ 568 "When HeapDumpOnOutOfMemoryError, HeapDumpBeforeFullGC " \ 569 "or HeapDumpAfterFullGC is on, the gzip compression " \ 570 "level of the dump file. 0 (the default) disables gzip " \ 571 "compression. Otherwise the level must be between 1 and 9.") \ 572 range(0, 9) \ 573 \ 574 product(ccstr, NativeMemoryTracking, DEBUG_ONLY("summary") NOT_DEBUG("off"), \ 575 "Native memory tracking options") \ 576 \ 577 product(bool, PrintNMTStatistics, false, DIAGNOSTIC, \ 578 "Print native memory tracking summary data if it is on") \ 579 \ 580 product(bool, LogCompilation, false, DIAGNOSTIC, \ 581 "Log compilation activity in detail to LogFile") \ 582 \ 583 product(bool, PrintCompilation, false, \ 584 "Print compilations") \ 585 \ 586 product(intx, RepeatCompilation, 0, DIAGNOSTIC, \ 587 "Repeat compilation without installing code (number of times)") \ 588 range(0, max_jint) \ 589 \ 590 product(bool, PrintExtendedThreadInfo, false, \ 591 "Print more information in thread dump") \ 592 \ 593 product(intx, ScavengeRootsInCode, 2, DIAGNOSTIC, \ 594 "0: do not allow scavengable oops in the code cache; " \ 595 "1: allow scavenging from the code cache; " \ 596 "2: emit as many constants as the compiler can see") \ 597 range(0, 2) \ 598 \ 599 product(bool, AlwaysRestoreFPU, false, \ 600 "Restore the FPU control word after every JNI call (expensive)") \ 601 \ 602 product(bool, PrintCompilation2, false, DIAGNOSTIC, \ 603 "Print additional statistics per compilation") \ 604 \ 605 product(bool, PrintAdapterHandlers, false, DIAGNOSTIC, \ 606 "Print code generated for i2c/c2i adapters") \ 607 \ 608 product(bool, VerifyAdapterCalls, trueInDebug, DIAGNOSTIC, \ 609 "Verify that i2c/c2i adapters are called properly") \ 610 \ 611 develop(bool, VerifyAdapterSharing, false, \ 612 "Verify that the code for shared adapters is the equivalent") \ 613 \ 614 product(bool, PrintAssembly, false, DIAGNOSTIC, \ 615 "Print assembly code (using external disassembler.so)") \ 616 \ 617 product(ccstr, PrintAssemblyOptions, nullptr, DIAGNOSTIC, \ 618 "Print options string passed to disassembler.so") \ 619 \ 620 develop(bool, PrintNMethodStatistics, false, \ 621 "Print a summary statistic for the generated nmethods") \ 622 \ 623 product(bool, PrintNMethods, false, DIAGNOSTIC, \ 624 "Print assembly code for nmethods when generated") \ 625 \ 626 product(bool, PrintNativeNMethods, false, DIAGNOSTIC, \ 627 "Print assembly code for native nmethods when generated") \ 628 \ 629 develop(bool, PrintDebugInfo, false, \ 630 "Print debug information for all nmethods when generated") \ 631 \ 632 develop(bool, PrintRelocations, false, \ 633 "Print relocation information for all nmethods when generated") \ 634 \ 635 develop(bool, PrintDependencies, false, \ 636 "Print dependency information for all nmethods when generated") \ 637 \ 638 develop(bool, PrintExceptionHandlers, false, \ 639 "Print exception handler tables for all nmethods when generated") \ 640 \ 641 develop(bool, StressCompiledExceptionHandlers, false, \ 642 "Exercise compiled exception handlers") \ 643 \ 644 develop(bool, InterceptOSException, false, \ 645 "Start debugger when an implicit OS (e.g. null pointer) " \ 646 "exception happens") \ 647 \ 648 product(bool, PrintCodeCache, false, \ 649 "Print the code cache memory usage when exiting") \ 650 \ 651 develop(bool, PrintCodeCache2, false, \ 652 "Print detailed usage information on the code cache when exiting")\ 653 \ 654 product(bool, PrintCodeCacheOnCompilation, false, \ 655 "Print the code cache memory usage each time a method is " \ 656 "compiled") \ 657 \ 658 product(bool, PrintCodeHeapAnalytics, false, DIAGNOSTIC, \ 659 "Print code heap usage statistics on exit and on full condition") \ 660 \ 661 product(bool, PrintStubCode, false, DIAGNOSTIC, \ 662 "Print generated stub code") \ 663 \ 664 product(bool, StackTraceInThrowable, true, \ 665 "Collect backtrace in throwable when exception happens") \ 666 \ 667 product(bool, OmitStackTraceInFastThrow, true, \ 668 "Omit backtraces for some 'hot' exceptions in optimized code") \ 669 \ 670 product(bool, ShowCodeDetailsInExceptionMessages, true, MANAGEABLE, \ 671 "Show exception messages from RuntimeExceptions that contain " \ 672 "snippets of the failing code. Disable this to improve privacy.") \ 673 \ 674 product(bool, PrintWarnings, true, \ 675 "Print JVM warnings to output stream") \ 676 \ 677 develop(bool, RegisterReferences, true, \ 678 "Tell whether the VM should register soft/weak/final/phantom " \ 679 "references") \ 680 \ 681 develop(bool, PrintCodeCacheExtension, false, \ 682 "Print extension of code cache") \ 683 \ 684 develop(bool, UsePrivilegedStack, true, \ 685 "Enable the security JVM functions") \ 686 \ 687 product(bool, ClassUnloading, true, \ 688 "Do unloading of classes") \ 689 \ 690 product(bool, ClassUnloadingWithConcurrentMark, true, \ 691 "Do unloading of classes with a concurrent marking cycle") \ 692 \ 693 develop(bool, PrintSystemDictionaryAtExit, false, \ 694 "Print the system dictionary at exit") \ 695 \ 696 develop(bool, PrintClassLoaderDataGraphAtExit, false, \ 697 "Print the class loader data graph at exit") \ 698 \ 699 product(bool, AllowParallelDefineClass, false, \ 700 "Allow parallel defineClass requests for class loaders " \ 701 "registering as parallel capable") \ 702 \ 703 product_pd(bool, DontYieldALot, \ 704 "(Deprecated) Throw away obvious excess yield calls") \ 705 \ 706 product(bool, DisablePrimordialThreadGuardPages, false, EXPERIMENTAL, \ 707 "Disable the use of stack guard pages if the JVM is loaded " \ 708 "on the primordial process thread") \ 709 \ 710 product(bool, DoJVMTIVirtualThreadTransitions, true, EXPERIMENTAL, \ 711 "Do JVMTI virtual thread mount/unmount transitions " \ 712 "(disabling this flag implies no JVMTI events are posted)") \ 713 \ 714 /* notice: the max range value here is max_jint, not max_intx */ \ 715 /* because of overflow issue */ \ 716 product(intx, AsyncDeflationInterval, 250, DIAGNOSTIC, \ 717 "Async deflate idle monitors every so many milliseconds when " \ 718 "MonitorUsedDeflationThreshold is exceeded (0 is off).") \ 719 range(0, max_jint) \ 720 \ 721 /* notice: the max range value here is max_jint, not max_intx */ \ 722 /* because of overflow issue */ \ 723 product(intx, GuaranteedAsyncDeflationInterval, 60000, DIAGNOSTIC, \ 724 "Async deflate idle monitors every so many milliseconds even " \ 725 "when MonitorUsedDeflationThreshold is NOT exceeded (0 is off).") \ 726 range(0, max_jint) \ 727 \ 728 product(size_t, AvgMonitorsPerThreadEstimate, 1024, DIAGNOSTIC, \ 729 "Used to estimate a variable ceiling based on number of threads " \ 730 "for use with MonitorUsedDeflationThreshold (0 is off).") \ 731 range(0, max_uintx) \ 732 \ 733 /* notice: the max range value here is max_jint, not max_intx */ \ 734 /* because of overflow issue */ \ 735 product(intx, MonitorDeflationMax, 1000000, DIAGNOSTIC, \ 736 "The maximum number of monitors to deflate, unlink and delete " \ 737 "at one time (minimum is 1024).") \ 738 range(1024, max_jint) \ 739 \ 740 product(intx, MonitorUnlinkBatch, 500, DIAGNOSTIC, \ 741 "The maximum number of monitors to unlink in one batch. ") \ 742 range(1, max_jint) \ 743 \ 744 product(int, MonitorUsedDeflationThreshold, 90, DIAGNOSTIC, \ 745 "Percentage of used monitors before triggering deflation (0 is " \ 746 "off). The check is performed on AsyncDeflationInterval or " \ 747 "GuaranteedAsyncDeflationInterval, whichever is lower.") \ 748 range(0, 100) \ 749 \ 750 product(uintx, NoAsyncDeflationProgressMax, 3, DIAGNOSTIC, \ 751 "Max number of no progress async deflation attempts to tolerate " \ 752 "before adjusting the in_use_list_ceiling up (0 is off).") \ 753 range(0, max_uintx) \ 754 \ 755 product(intx, hashCode, 5, EXPERIMENTAL, \ 756 "(Unstable) select hashCode generation algorithm") \ 757 \ 758 product(bool, ReduceSignalUsage, false, \ 759 "Reduce the use of OS signals in Java and/or the VM") \ 760 \ 761 develop(bool, LoadLineNumberTables, true, \ 762 "Tell whether the class file parser loads line number tables") \ 763 \ 764 develop(bool, LoadLocalVariableTables, true, \ 765 "Tell whether the class file parser loads local variable tables") \ 766 \ 767 develop(bool, LoadLocalVariableTypeTables, true, \ 768 "Tell whether the class file parser loads local variable type" \ 769 "tables") \ 770 \ 771 product(bool, AllowUserSignalHandlers, false, \ 772 "Application will install primary signal handlers for the JVM " \ 773 "(Unix only)") \ 774 \ 775 product(bool, UseSignalChaining, true, \ 776 "Use signal-chaining to invoke signal handlers installed " \ 777 "by the application (Unix only)") \ 778 \ 779 product(bool, RestoreMXCSROnJNICalls, false, \ 780 "Restore MXCSR when returning from JNI calls") \ 781 \ 782 product(bool, CheckJNICalls, false, \ 783 "Verify all arguments to JNI calls") \ 784 \ 785 product(bool, UseFastJNIAccessors, true, \ 786 "Use optimized versions of Get<Primitive>Field") \ 787 \ 788 product(intx, MaxJNILocalCapacity, 65536, \ 789 "Maximum allowable local JNI handle capacity to " \ 790 "EnsureLocalCapacity() and PushLocalFrame(), " \ 791 "where <= 0 is unlimited, default: 65536") \ 792 range(min_intx, max_intx) \ 793 \ 794 product(bool, EagerXrunInit, false, \ 795 "Eagerly initialize -Xrun libraries; allows startup profiling, " \ 796 "but not all -Xrun libraries may support the state of the VM " \ 797 "at this time") \ 798 \ 799 product(bool, PreserveAllAnnotations, false, \ 800 "(Deprecated) Preserve RuntimeInvisibleAnnotations as well " \ 801 "as RuntimeVisibleAnnotations") \ 802 \ 803 develop(uintx, PreallocatedOutOfMemoryErrorCount, 4, \ 804 "Number of OutOfMemoryErrors preallocated with backtrace") \ 805 \ 806 product(bool, UseXMMForArrayCopy, false, \ 807 "Use SSE2 MOVQ instruction for Arraycopy") \ 808 \ 809 develop(bool, PrintFieldLayout, false, \ 810 "Print field layout for each class") \ 811 \ 812 /* Need to limit the extent of the padding to reasonable size. */\ 813 /* 8K is well beyond the reasonable HW cache line size, even with */\ 814 /* aggressive prefetching, while still leaving the room for segregating */\ 815 /* among the distinct pages. */\ 816 product(int, ContendedPaddingWidth, 128, \ 817 "How many bytes to pad the fields/classes marked @Contended with")\ 818 range(0, 8192) \ 819 constraint(ContendedPaddingWidthConstraintFunc,AfterErgo) \ 820 \ 821 product(bool, EnableContended, true, \ 822 "Enable @Contended annotation support") \ 823 \ 824 product(bool, RestrictContended, true, \ 825 "Restrict @Contended to trusted classes") \ 826 \ 827 product(int, DiagnoseSyncOnValueBasedClasses, 0, DIAGNOSTIC, \ 828 "Detect and take action upon identifying synchronization on " \ 829 "value based classes. Modes: " \ 830 "0: off; " \ 831 "1: exit with fatal error; " \ 832 "2: log message to stdout. Output file can be specified with " \ 833 " -Xlog:valuebasedclasses. If JFR is running it will " \ 834 " also generate JFR events.") \ 835 range(0, 2) \ 836 \ 837 product(bool, ExitOnOutOfMemoryError, false, \ 838 "JVM exits on the first occurrence of an out-of-memory error " \ 839 "thrown from JVM") \ 840 \ 841 product(bool, CrashOnOutOfMemoryError, false, \ 842 "JVM aborts, producing an error log and core/mini dump, on the " \ 843 "first occurrence of an out-of-memory error thrown from JVM") \ 844 \ 845 product(intx, UserThreadWaitAttemptsAtExit, 30, \ 846 "The number of times to wait for user threads to stop executing " \ 847 "native code during JVM exit. Each wait lasts 10 milliseconds. " \ 848 "The maximum number of waits is 1000, to wait at most 10 " \ 849 "seconds.") \ 850 range(0, 1000) \ 851 \ 852 /* tracing */ \ 853 \ 854 develop(bool, StressRewriter, false, \ 855 "Stress linktime bytecode rewriting") \ 856 \ 857 product(ccstr, TraceJVMTI, nullptr, \ 858 "Trace flags for JVMTI functions and events") \ 859 \ 860 product(bool, StressLdcRewrite, false, DIAGNOSTIC, \ 861 "Force ldc -> ldc_w rewrite during RedefineClasses. " \ 862 "This option can change an EMCP method into an obsolete method " \ 863 "and can affect tests that expect specific methods to be EMCP. " \ 864 "This option should be used with caution.") \ 865 \ 866 product(bool, AllowRedefinitionToAddDeleteMethods, false, \ 867 "(Deprecated) Allow redefinition to add and delete private " \ 868 "static or final methods for compatibility with old releases") \ 869 \ 870 develop(bool, TraceBytecodes, false, \ 871 "Trace bytecode execution") \ 872 \ 873 develop(bool, VerifyDependencies, trueInDebug, \ 874 "Exercise and verify the compilation dependency mechanism") \ 875 \ 876 develop(bool, TraceNewOopMapGeneration, false, \ 877 "Trace OopMapGeneration") \ 878 \ 879 develop(bool, TraceNewOopMapGenerationDetailed, false, \ 880 "Trace OopMapGeneration: print detailed cell states") \ 881 \ 882 develop(bool, TimeOopMap, false, \ 883 "Time calls to GenerateOopMap::compute_map() in sum") \ 884 \ 885 develop(bool, TimeOopMap2, false, \ 886 "Time calls to GenerateOopMap::compute_map() individually") \ 887 \ 888 develop(bool, TraceOopMapRewrites, false, \ 889 "Trace rewriting of methods during oop map generation") \ 890 \ 891 develop(bool, TraceFinalizerRegistration, false, \ 892 "Trace registration of final references") \ 893 \ 894 product(bool, IgnoreEmptyClassPaths, false, \ 895 "Ignore empty path elements in -classpath") \ 896 \ 897 product(bool, PrintHeapAtSIGBREAK, true, \ 898 "Print heap layout in response to SIGBREAK") \ 899 \ 900 product(bool, PrintClassHistogram, false, MANAGEABLE, \ 901 "Print a histogram of class instances") \ 902 \ 903 product(double, ObjectCountCutOffPercent, 0.5, EXPERIMENTAL, \ 904 "The percentage of the used heap that the instances of a class " \ 905 "must occupy for the class to generate a trace event") \ 906 range(0.0, 100.0) \ 907 \ 908 /* JVMTI heap profiling */ \ 909 \ 910 product(bool, VerifyBeforeIteration, false, DIAGNOSTIC, \ 911 "Verify memory system before JVMTI iteration") \ 912 \ 913 /* compiler */ \ 914 \ 915 /* notice: the max range value here is max_jint, not max_intx */ \ 916 /* because of overflow issue */ \ 917 product(intx, CICompilerCount, CI_COMPILER_COUNT, \ 918 "Number of compiler threads to run") \ 919 range(0, max_jint) \ 920 constraint(CICompilerCountConstraintFunc, AfterErgo) \ 921 \ 922 product(bool, UseDynamicNumberOfCompilerThreads, true, \ 923 "Dynamically choose the number of parallel compiler threads") \ 924 \ 925 product(bool, ReduceNumberOfCompilerThreads, true, DIAGNOSTIC, \ 926 "Reduce the number of parallel compiler threads when they " \ 927 "are not used") \ 928 \ 929 product(bool, TraceCompilerThreads, false, DIAGNOSTIC, \ 930 "Trace creation and removal of compiler threads") \ 931 \ 932 product(ccstr, LogClassLoadingCauseFor, nullptr, \ 933 "Apply -Xlog:class+load+cause* to classes whose fully " \ 934 "qualified name contains this string (\"*\" matches " \ 935 "any class).") \ 936 \ 937 develop(bool, InjectCompilerCreationFailure, false, \ 938 "Inject thread creation failures for " \ 939 "UseDynamicNumberOfCompilerThreads") \ 940 \ 941 develop(bool, GenerateSynchronizationCode, true, \ 942 "generate locking/unlocking code for synchronized methods and " \ 943 "monitors") \ 944 \ 945 product_pd(bool, ImplicitNullChecks, DIAGNOSTIC, \ 946 "Generate code for implicit null checks") \ 947 \ 948 product_pd(bool, TrapBasedNullChecks, \ 949 "Generate code for null checks that uses a cmp and trap " \ 950 "instruction raising SIGTRAP. This is only used if an access to" \ 951 "null (+offset) will not raise a SIGSEGV, i.e.," \ 952 "ImplicitNullChecks don't work (PPC64).") \ 953 \ 954 product(bool, EnableThreadSMRStatistics, trueInDebug, DIAGNOSTIC, \ 955 "Enable Thread SMR Statistics") \ 956 \ 957 product(bool, UseNotificationThread, true, \ 958 "(Deprecated) Use Notification Thread") \ 959 \ 960 product(bool, Inline, true, \ 961 "Enable inlining") \ 962 \ 963 product(bool, ClipInlining, true, \ 964 "Clip inlining if aggregate method exceeds DesiredMethodLimit") \ 965 \ 966 develop(bool, UseCHA, true, \ 967 "Enable CHA") \ 968 \ 969 product(bool, UseVtableBasedCHA, true, DIAGNOSTIC, \ 970 "Use vtable information during CHA") \ 971 \ 972 product(bool, UseTypeProfile, true, \ 973 "Check interpreter profile for historically monomorphic calls") \ 974 \ 975 product(bool, PrintInlining, false, DIAGNOSTIC, \ 976 "Print inlining optimizations") \ 977 \ 978 product(bool, UsePopCountInstruction, false, \ 979 "Use population count instruction") \ 980 \ 981 develop(bool, TraceMethodReplacement, false, \ 982 "Print when methods are replaced do to recompilation") \ 983 \ 984 product(intx, MinPassesBeforeFlush, 10, DIAGNOSTIC, \ 985 "Minimum number of sweeper passes before an nmethod " \ 986 "can be flushed") \ 987 range(0, max_intx) \ 988 \ 989 develop(bool, StressCodeBuffers, false, \ 990 "Exercise code buffer expansion and other rare state changes") \ 991 \ 992 product(bool, DebugNonSafepoints, trueInDebug, DIAGNOSTIC, \ 993 "Generate extra debugging information for non-safepoints in " \ 994 "nmethods") \ 995 \ 996 product(bool, PrintVMOptions, false, \ 997 "Print flags that appeared on the command line") \ 998 \ 999 product(bool, IgnoreUnrecognizedVMOptions, false, \ 1000 "Ignore unrecognized VM options") \ 1001 \ 1002 product(bool, PrintCommandLineFlags, false, \ 1003 "Print flags specified on command line or set by ergonomics") \ 1004 \ 1005 product(bool, PrintFlagsInitial, false, \ 1006 "Print all VM flags before argument processing and exit VM") \ 1007 \ 1008 product(bool, PrintFlagsFinal, false, \ 1009 "Print all VM flags after argument and ergonomic processing") \ 1010 \ 1011 develop(bool, PrintFlagsWithComments, false, \ 1012 "Print all VM flags with default values and descriptions and " \ 1013 "exit") \ 1014 \ 1015 product(bool, PrintFlagsRanges, false, \ 1016 "Print VM flags and their ranges") \ 1017 \ 1018 product(bool, SerializeVMOutput, true, DIAGNOSTIC, \ 1019 "Use a mutex to serialize output to tty and LogFile") \ 1020 \ 1021 product(bool, DisplayVMOutput, true, DIAGNOSTIC, \ 1022 "Display all VM output on the tty, independently of LogVMOutput") \ 1023 \ 1024 product(bool, LogVMOutput, false, DIAGNOSTIC, \ 1025 "Save VM output to LogFile") \ 1026 \ 1027 product(ccstr, LogFile, nullptr, DIAGNOSTIC, \ 1028 "If LogVMOutput or LogCompilation is on, save VM output to " \ 1029 "this file [default: ./hotspot_%p.log] (%p replaced with pidNNN)")\ 1030 \ 1031 product(ccstr, ErrorFile, nullptr, \ 1032 "If an error occurs, save the error data to this file " \ 1033 "[default: ./hs_err_%p.log] (%p replaced with pidNNN)") \ 1034 \ 1035 product(bool, ExtensiveErrorReports, \ 1036 PRODUCT_ONLY(false) NOT_PRODUCT(true), \ 1037 "Error reports are more extensive.") \ 1038 \ 1039 product(bool, DisplayVMOutputToStderr, false, \ 1040 "If DisplayVMOutput is true, display all VM output to stderr") \ 1041 \ 1042 product(bool, DisplayVMOutputToStdout, false, \ 1043 "If DisplayVMOutput is true, display all VM output to stdout") \ 1044 \ 1045 product(bool, ErrorFileToStderr, false, \ 1046 "If true, error data is printed to stderr instead of a file") \ 1047 \ 1048 product(bool, ErrorFileToStdout, false, \ 1049 "If true, error data is printed to stdout instead of a file") \ 1050 \ 1051 develop(bool, VerifyHeavyMonitors, false, \ 1052 "Checks that no stack locking happens when using " \ 1053 "-XX:LockingMode=0 (LM_MONITOR)") \ 1054 \ 1055 product(bool, PrintStringTableStatistics, false, \ 1056 "print statistics about the StringTable and SymbolTable") \ 1057 \ 1058 product(bool, VerifyStringTableAtExit, false, DIAGNOSTIC, \ 1059 "verify StringTable contents at exit") \ 1060 \ 1061 develop(bool, PrintSymbolTableSizeHistogram, false, \ 1062 "print histogram of the symbol table") \ 1063 \ 1064 product(ccstr, AbortVMOnException, nullptr, DIAGNOSTIC, \ 1065 "Call fatal if this exception is thrown. Example: " \ 1066 "java -XX:AbortVMOnException=java.lang.NullPointerException Foo") \ 1067 \ 1068 product(ccstr, AbortVMOnExceptionMessage, nullptr, DIAGNOSTIC, \ 1069 "Call fatal if the exception pointed by AbortVMOnException " \ 1070 "has this message") \ 1071 \ 1072 develop(bool, DebugVtables, false, \ 1073 "add debugging code to vtable dispatch") \ 1074 \ 1075 product(bool, RangeCheckElimination, true, \ 1076 "Eliminate range checks") \ 1077 \ 1078 develop_pd(bool, UncommonNullCast, \ 1079 "track occurrences of null in casts; adjust compiler tactics") \ 1080 \ 1081 develop(bool, TypeProfileCasts, true, \ 1082 "treat casts like calls for purposes of type profiling") \ 1083 \ 1084 develop(bool, TraceLivenessGen, false, \ 1085 "Trace the generation of liveness analysis information") \ 1086 \ 1087 develop(bool, TraceLivenessQuery, false, \ 1088 "Trace queries of liveness analysis information") \ 1089 \ 1090 develop(bool, CollectIndexSetStatistics, false, \ 1091 "Collect information about IndexSets") \ 1092 \ 1093 develop(int, FastAllocateSizeLimit, 128*K, \ 1094 /* Note: This value is zero mod 1<<13 for a cheap sparc set. */ \ 1095 "Inline allocations larger than this in doublewords must go slow")\ 1096 \ 1097 product_pd(bool, CompactStrings, \ 1098 "Enable Strings to use single byte chars in backing store") \ 1099 \ 1100 product_pd(uint, TypeProfileLevel, \ 1101 "=XYZ, with Z: Type profiling of arguments at call; " \ 1102 "Y: Type profiling of return value at call; " \ 1103 "X: Type profiling of parameters to methods; " \ 1104 "X, Y and Z in 0=off ; 1=jsr292 only; 2=all methods") \ 1105 constraint(TypeProfileLevelConstraintFunc, AfterErgo) \ 1106 \ 1107 product(int, TypeProfileArgsLimit, 2, \ 1108 "max number of call arguments to consider for type profiling") \ 1109 range(0, 16) \ 1110 \ 1111 product(int, TypeProfileParmsLimit, 2, \ 1112 "max number of incoming parameters to consider for type profiling"\ 1113 ", -1 for all") \ 1114 range(-1, 64) \ 1115 \ 1116 /* statistics */ \ 1117 develop(bool, CountCompiledCalls, false, \ 1118 "Count method invocations") \ 1119 \ 1120 develop(bool, ICMissHistogram, false, \ 1121 "Produce histogram of IC misses") \ 1122 \ 1123 /* interpreter */ \ 1124 product_pd(bool, RewriteBytecodes, \ 1125 "Allow rewriting of bytecodes (bytecodes are not immutable)") \ 1126 \ 1127 product_pd(bool, RewriteFrequentPairs, \ 1128 "Rewrite frequently used bytecode pairs into a single bytecode") \ 1129 \ 1130 product(bool, PrintInterpreter, false, DIAGNOSTIC, \ 1131 "Print the generated interpreter code") \ 1132 \ 1133 product(bool, UseInterpreter, true, \ 1134 "Use interpreter for non-compiled methods") \ 1135 \ 1136 develop(bool, UseFastSignatureHandlers, true, \ 1137 "Use fast signature handlers for native calls") \ 1138 \ 1139 product(bool, UseLoopCounter, true, \ 1140 "Increment invocation counter on backward branch") \ 1141 \ 1142 product_pd(bool, UseOnStackReplacement, \ 1143 "Use on stack replacement, calls runtime if invoc. counter " \ 1144 "overflows in loop") \ 1145 \ 1146 develop(bool, TraceOnStackReplacement, false, \ 1147 "Trace on stack replacement") \ 1148 \ 1149 product_pd(bool, PreferInterpreterNativeStubs, \ 1150 "Use always interpreter stubs for native methods invoked via " \ 1151 "interpreter") \ 1152 \ 1153 product(bool, CountBytecodes, false, DIAGNOSTIC, \ 1154 "Count number of bytecodes executed") \ 1155 \ 1156 product(bool, CountBytecodesPerThread, false, DIAGNOSTIC, \ 1157 "Count number of bytecodes executed per thread") \ 1158 \ 1159 product(bool, PrintBytecodeHistogram, false, DIAGNOSTIC, \ 1160 "Print histogram of the executed bytecodes") \ 1161 \ 1162 product(double, PrintBytecodeHistogramCutoff, 0.01, \ 1163 "Print cutoff for histogram of the executed bytecodes") \ 1164 range(0.0, 100.0) \ 1165 \ 1166 develop(bool, PrintBytecodePairHistogram, false, \ 1167 "Print histogram of the executed bytecode pairs") \ 1168 \ 1169 product(bool, PrintSignatureHandlers, false, DIAGNOSTIC, \ 1170 "Print code generated for native method signature handlers") \ 1171 \ 1172 develop(bool, VerifyOops, false, \ 1173 "Do plausibility checks for oops") \ 1174 \ 1175 develop(bool, CheckUnhandledOops, false, \ 1176 "Check for unhandled oops in VM code") \ 1177 \ 1178 develop(bool, VerifyJNIFields, trueInDebug, \ 1179 "Verify jfieldIDs for instance fields") \ 1180 \ 1181 develop(bool, VerifyFPU, false, \ 1182 "Verify FPU state (check for NaN's, etc.)") \ 1183 \ 1184 develop(bool, VerifyActivationFrameSize, false, \ 1185 "Verify that activation frame didn't become smaller than its " \ 1186 "minimal size") \ 1187 \ 1188 develop(bool, TraceFrequencyInlining, false, \ 1189 "Trace frequency based inlining") \ 1190 \ 1191 develop_pd(bool, InlineIntrinsics, \ 1192 "Use intrinsics in Interpreter that can be statically resolved") \ 1193 \ 1194 product_pd(bool, ProfileInterpreter, \ 1195 "Profile at the bytecode level during interpretation") \ 1196 \ 1197 develop_pd(bool, ProfileTraps, \ 1198 "Profile deoptimization traps at the bytecode level") \ 1199 \ 1200 product(intx, ProfileMaturityPercentage, 20, \ 1201 "number of method invocations/branches (expressed as % of " \ 1202 "CompileThreshold) before using the method's profile") \ 1203 range(0, 100) \ 1204 \ 1205 product(bool, ForceProfiling, false, DIAGNOSTIC, \ 1206 "Eagerly allocate MDOs") \ 1207 \ 1208 product(bool, PrintMethodData, false, DIAGNOSTIC, \ 1209 "Print the results of +ProfileInterpreter at end of run") \ 1210 \ 1211 develop(bool, VerifyDataPointer, trueInDebug, \ 1212 "Verify the method data pointer during interpreter profiling") \ 1213 \ 1214 develop(bool, CrashGCForDumpingJavaThread, false, \ 1215 "Manually make GC thread crash then dump java stack trace; " \ 1216 "Test only") \ 1217 \ 1218 /* compilation */ \ 1219 product(bool, UseCompiler, true, \ 1220 "Use Just-In-Time compilation") \ 1221 \ 1222 develop(intx, CounterHalfLifeTime, 30, \ 1223 "Half-life time of invocation counters (in seconds)") \ 1224 \ 1225 product(bool, AlwaysCompileLoopMethods, false, \ 1226 "When using recompilation, never interpret methods " \ 1227 "containing loops") \ 1228 \ 1229 product(int, AllocatePrefetchStyle, 1, \ 1230 "0 = no prefetch, " \ 1231 "1 = generate prefetch instructions for each allocation, " \ 1232 "2 = use TLAB watermark to gate allocation prefetch, " \ 1233 "3 = generate one prefetch instruction per cache line") \ 1234 range(0, 3) \ 1235 \ 1236 product(int, AllocatePrefetchDistance, -1, \ 1237 "Distance to prefetch ahead of allocation pointer. " \ 1238 "-1: use system-specific value (automatically determined") \ 1239 range(-1, 512) \ 1240 \ 1241 product(int, AllocatePrefetchLines, 3, \ 1242 "Number of lines to prefetch ahead of array allocation pointer") \ 1243 range(1, 64) \ 1244 \ 1245 product(int, AllocateInstancePrefetchLines, 1, \ 1246 "Number of lines to prefetch ahead of instance allocation " \ 1247 "pointer") \ 1248 range(1, 64) \ 1249 \ 1250 product(int, AllocatePrefetchStepSize, 16, \ 1251 "Step size in bytes of sequential prefetch instructions") \ 1252 range(1, 512) \ 1253 constraint(AllocatePrefetchStepSizeConstraintFunc,AfterMemoryInit)\ 1254 \ 1255 product(intx, AllocatePrefetchInstr, 0, \ 1256 "Select instruction to prefetch ahead of allocation pointer") \ 1257 constraint(AllocatePrefetchInstrConstraintFunc, AfterMemoryInit) \ 1258 \ 1259 /* deoptimization */ \ 1260 product(bool, TraceDeoptimization, false, DIAGNOSTIC, \ 1261 "Trace deoptimization") \ 1262 \ 1263 develop(bool, PrintDeoptimizationDetails, false, \ 1264 "Print more information about deoptimization") \ 1265 \ 1266 develop(bool, DebugDeoptimization, false, \ 1267 "Tracing various information while debugging deoptimization") \ 1268 \ 1269 product(double, SelfDestructTimer, 0.0, \ 1270 "Will cause VM to terminate after a given time " \ 1271 "(in fractional minutes) " \ 1272 "(0.0 means off)") \ 1273 range(0.0, (double)max_intx) \ 1274 \ 1275 product(int, MaxJavaStackTraceDepth, 1024, \ 1276 "The maximum number of lines in the stack trace for Java " \ 1277 "exceptions (0 means all)") \ 1278 range(0, max_jint/2) \ 1279 \ 1280 /* notice: the max range value here is max_jint, not max_intx */ \ 1281 /* because of overflow issue */ \ 1282 product(intx, GuaranteedSafepointInterval, 0, DIAGNOSTIC, \ 1283 "Guarantee a safepoint (at least) every so many milliseconds " \ 1284 "(0 means none)") \ 1285 range(0, max_jint) \ 1286 \ 1287 product(intx, ServiceThreadCleanupInterval, 1000, DIAGNOSTIC, \ 1288 "Wake the ServiceThread to do periodic cleanup checks every so " \ 1289 "many milliseconds (0 means none)") \ 1290 range(0, max_jint) \ 1291 \ 1292 product(double, SafepointTimeoutDelay, 10000, \ 1293 "Delay in milliseconds for option SafepointTimeout; " \ 1294 "supports sub-millisecond resolution with fractional values.") \ 1295 range(0, max_jlongDouble LP64_ONLY(/MICROUNITS)) \ 1296 \ 1297 product(bool, UseSystemMemoryBarrier, false, \ 1298 "Try to enable system memory barrier if supported by OS") \ 1299 \ 1300 product(intx, NmethodSweepActivity, 4, \ 1301 "Removes cold nmethods from code cache if > 0. Higher values " \ 1302 "result in more aggressive sweeping") \ 1303 range(0, 2000) \ 1304 \ 1305 develop(intx, MallocCatchPtr, -1, \ 1306 "Hit breakpoint when mallocing/freeing this pointer") \ 1307 \ 1308 develop(int, StackPrintLimit, 100, \ 1309 "number of stack frames to print in VM-level stack dump") \ 1310 \ 1311 product(int, ErrorLogPrintCodeLimit, 3, DIAGNOSTIC, \ 1312 "max number of compiled code units to print in error log") \ 1313 range(0, VMError::max_error_log_print_code) \ 1314 \ 1315 develop(int, MaxElementPrintSize, 256, \ 1316 "maximum number of elements to print") \ 1317 \ 1318 develop(intx, MaxSubklassPrintSize, 4, \ 1319 "maximum number of subklasses to print when printing klass") \ 1320 \ 1321 develop(intx, MaxForceInlineLevel, 100, \ 1322 "maximum number of nested calls that are forced for inlining " \ 1323 "(using CompileCommand or marked w/ @ForceInline)") \ 1324 range(0, max_jint) \ 1325 \ 1326 develop(intx, MethodHistogramCutoff, 100, \ 1327 "The cutoff value for method invocation histogram (+CountCalls)") \ 1328 \ 1329 develop(intx, DeoptimizeALotInterval, 5, \ 1330 "Number of exits until DeoptimizeALot kicks in") \ 1331 \ 1332 develop(intx, ZombieALotInterval, 5, \ 1333 "Number of exits until ZombieALot kicks in") \ 1334 \ 1335 product(ccstr, MallocLimit, nullptr, DIAGNOSTIC, \ 1336 "Limit malloc allocation size from VM. Reaching a limit will " \ 1337 "trigger an action (see flag). This feature requires " \ 1338 "NativeMemoryTracking=summary or NativeMemoryTracking=detail." \ 1339 "Usage:" \ 1340 "\"-XX:MallocLimit=<size>[:<flag>]\" sets a total limit." \ 1341 "\"-XX:MallocLimit=<category>:<size>[:<flag>][,<category>:<size>[:<flag>] ...]\"" \ 1342 "sets one or more category-specific limits." \ 1343 "<flag> defines the action upon reaching the limit:" \ 1344 "\"fatal\": end VM with a fatal error at the allocation site" \ 1345 "\"oom\" : will mimic a native OOM" \ 1346 "If <flag> is omitted, \"fatal\" is the default." \ 1347 "Examples:\n" \ 1348 "-XX:MallocLimit=2g" \ 1349 "-XX:MallocLimit=2g:oom" \ 1350 "-XX:MallocLimit=compiler:200m:oom,code:100m") \ 1351 \ 1352 product(intx, TypeProfileWidth, 2, \ 1353 "Number of receiver types to record in call/cast profile") \ 1354 range(0, 8) \ 1355 \ 1356 develop(intx, BciProfileWidth, 2, \ 1357 "Number of return bci's to record in ret profile") \ 1358 \ 1359 product(intx, PerMethodRecompilationCutoff, 400, \ 1360 "After recompiling N times, stay in the interpreter (-1=>'Inf')") \ 1361 range(-1, max_intx) \ 1362 \ 1363 product(intx, PerBytecodeRecompilationCutoff, 200, \ 1364 "Per-BCI limit on repeated recompilation (-1=>'Inf')") \ 1365 range(-1, max_intx) \ 1366 \ 1367 product(intx, PerMethodTrapLimit, 100, \ 1368 "Limit on traps (of one kind) in a method (includes inlines)") \ 1369 range(0, max_jint) \ 1370 \ 1371 product(intx, PerMethodSpecTrapLimit, 5000, EXPERIMENTAL, \ 1372 "Limit on speculative traps (of one kind) in a method " \ 1373 "(includes inlines)") \ 1374 range(0, max_jint) \ 1375 \ 1376 product(intx, PerBytecodeTrapLimit, 4, \ 1377 "Limit on traps (of one kind) at a particular BCI") \ 1378 range(0, max_jint) \ 1379 \ 1380 product(int, SpecTrapLimitExtraEntries, 3, EXPERIMENTAL, \ 1381 "Extra method data trap entries for speculation") \ 1382 \ 1383 product(double, InlineFrequencyRatio, 0.25, DIAGNOSTIC, \ 1384 "Ratio of call site execution to caller method invocation") \ 1385 \ 1386 product(double, MinInlineFrequencyRatio, 0.0085, DIAGNOSTIC, \ 1387 "Minimum ratio of call site execution to caller method" \ 1388 "invocation to be considered for inlining") \ 1389 \ 1390 develop(intx, InlineThrowCount, 50, \ 1391 "Force inlining of interpreted methods that throw this often") \ 1392 range(0, max_jint) \ 1393 \ 1394 develop(intx, InlineThrowMaxSize, 200, \ 1395 "Force inlining of throwing methods smaller than this") \ 1396 range(0, max_jint) \ 1397 \ 1398 product(size_t, MetaspaceSize, NOT_LP64(16 * M) LP64_ONLY(21 * M), \ 1399 "Initial threshold (in bytes) at which a garbage collection " \ 1400 "is done to reduce Metaspace usage") \ 1401 constraint(MetaspaceSizeConstraintFunc,AfterErgo) \ 1402 \ 1403 product(size_t, MaxMetaspaceSize, max_uintx, \ 1404 "Maximum size of Metaspaces (in bytes)") \ 1405 constraint(MaxMetaspaceSizeConstraintFunc,AfterErgo) \ 1406 \ 1407 product(size_t, CompressedClassSpaceSize, 1*G, \ 1408 "Maximum size of class area in Metaspace when compressed " \ 1409 "class pointers are used") \ 1410 range(1*M, 3*G) \ 1411 \ 1412 develop(size_t, CompressedClassSpaceBaseAddress, 0, \ 1413 "Force the class space to be allocated at this address or " \ 1414 "fails VM initialization (requires -Xshare=off.") \ 1415 \ 1416 develop(bool, RandomizeClassSpaceLocation, true, \ 1417 "Randomize location of class space.") \ 1418 \ 1419 product(bool, PrintMetaspaceStatisticsAtExit, false, DIAGNOSTIC, \ 1420 "Print metaspace statistics upon VM exit.") \ 1421 \ 1422 develop(bool, MetaspaceGuardAllocations, false, \ 1423 "Metapace allocations are guarded.") \ 1424 \ 1425 product(uintx, MinHeapFreeRatio, 40, MANAGEABLE, \ 1426 "The minimum percentage of heap free after GC to avoid expansion."\ 1427 " For most GCs this applies to the old generation. In G1 and" \ 1428 " ParallelGC it applies to the whole heap.") \ 1429 range(0, 100) \ 1430 constraint(MinHeapFreeRatioConstraintFunc,AfterErgo) \ 1431 \ 1432 product(uintx, MaxHeapFreeRatio, 70, MANAGEABLE, \ 1433 "The maximum percentage of heap free after GC to avoid shrinking."\ 1434 " For most GCs this applies to the old generation. In G1 and" \ 1435 " ParallelGC it applies to the whole heap.") \ 1436 range(0, 100) \ 1437 constraint(MaxHeapFreeRatioConstraintFunc,AfterErgo) \ 1438 \ 1439 product(bool, ShrinkHeapInSteps, true, \ 1440 "When disabled, informs the GC to shrink the java heap directly" \ 1441 " to the target size at the next full GC rather than requiring" \ 1442 " smaller steps during multiple full GCs.") \ 1443 \ 1444 product(intx, SoftRefLRUPolicyMSPerMB, 1000, \ 1445 "Number of milliseconds per MB of free space in the heap") \ 1446 range(0, max_intx) \ 1447 constraint(SoftRefLRUPolicyMSPerMBConstraintFunc,AfterMemoryInit) \ 1448 \ 1449 product(size_t, MinHeapDeltaBytes, ScaleForWordSize(128*K), \ 1450 "The minimum change in heap space due to GC (in bytes)") \ 1451 range(0, max_uintx) \ 1452 \ 1453 product(size_t, MinMetaspaceExpansion, ScaleForWordSize(256*K), \ 1454 "The minimum expansion of Metaspace (in bytes)") \ 1455 range(0, max_uintx) \ 1456 \ 1457 product(uint, MaxMetaspaceFreeRatio, 70, \ 1458 "The maximum percentage of Metaspace free after GC to avoid " \ 1459 "shrinking") \ 1460 range(0, 100) \ 1461 constraint(MaxMetaspaceFreeRatioConstraintFunc,AfterErgo) \ 1462 \ 1463 product(uint, MinMetaspaceFreeRatio, 40, \ 1464 "The minimum percentage of Metaspace free after GC to avoid " \ 1465 "expansion") \ 1466 range(0, 99) \ 1467 constraint(MinMetaspaceFreeRatioConstraintFunc,AfterErgo) \ 1468 \ 1469 product(size_t, MaxMetaspaceExpansion, ScaleForWordSize(4*M), \ 1470 "The maximum expansion of Metaspace without full GC (in bytes)") \ 1471 range(0, max_uintx) \ 1472 \ 1473 /* stack parameters */ \ 1474 product_pd(intx, StackYellowPages, \ 1475 "Number of yellow zone (recoverable overflows) pages of size " \ 1476 "4KB. If pages are bigger yellow zone is aligned up.") \ 1477 range(MIN_STACK_YELLOW_PAGES, (DEFAULT_STACK_YELLOW_PAGES+5)) \ 1478 \ 1479 product_pd(intx, StackRedPages, \ 1480 "Number of red zone (unrecoverable overflows) pages of size " \ 1481 "4KB. If pages are bigger red zone is aligned up.") \ 1482 range(MIN_STACK_RED_PAGES, (DEFAULT_STACK_RED_PAGES+2)) \ 1483 \ 1484 product_pd(intx, StackReservedPages, \ 1485 "Number of reserved zone (reserved to annotated methods) pages" \ 1486 " of size 4KB. If pages are bigger reserved zone is aligned up.") \ 1487 range(MIN_STACK_RESERVED_PAGES, (DEFAULT_STACK_RESERVED_PAGES+10))\ 1488 \ 1489 product(bool, RestrictReservedStack, true, \ 1490 "Restrict @ReservedStackAccess to trusted classes") \ 1491 \ 1492 /* greater stack shadow pages can't generate instruction to bang stack */ \ 1493 product_pd(intx, StackShadowPages, \ 1494 "Number of shadow zone (for overflow checking) pages of size " \ 1495 "4KB. If pages are bigger shadow zone is aligned up. " \ 1496 "This should exceed the depth of the VM and native call stack.") \ 1497 range(MIN_STACK_SHADOW_PAGES, (DEFAULT_STACK_SHADOW_PAGES+30)) \ 1498 \ 1499 product_pd(intx, ThreadStackSize, \ 1500 "Thread Stack Size (in Kbytes)") \ 1501 range(0, 1 * M) \ 1502 \ 1503 product_pd(intx, VMThreadStackSize, \ 1504 "Non-Java Thread Stack Size (in Kbytes)") \ 1505 range(0, max_intx/(1 * K)) \ 1506 \ 1507 product_pd(intx, CompilerThreadStackSize, \ 1508 "Compiler Thread Stack Size (in Kbytes)") \ 1509 range(0, max_intx/(1 * K)) \ 1510 \ 1511 develop_pd(size_t, JVMInvokeMethodSlack, \ 1512 "Stack space (bytes) required for JVM_InvokeMethod to complete") \ 1513 \ 1514 /* code cache parameters */ \ 1515 product_pd(uintx, CodeCacheSegmentSize, EXPERIMENTAL, \ 1516 "Code cache segment size (in bytes) - smallest unit of " \ 1517 "allocation") \ 1518 range(1, 1024) \ 1519 constraint(CodeCacheSegmentSizeConstraintFunc, AfterErgo) \ 1520 \ 1521 product_pd(intx, CodeEntryAlignment, EXPERIMENTAL, \ 1522 "Code entry alignment for generated code (in bytes)") \ 1523 constraint(CodeEntryAlignmentConstraintFunc, AfterErgo) \ 1524 \ 1525 product_pd(intx, OptoLoopAlignment, \ 1526 "Align inner loops to zero relative to this modulus") \ 1527 range(1, 128) \ 1528 constraint(OptoLoopAlignmentConstraintFunc, AfterErgo) \ 1529 \ 1530 product_pd(uintx, InitialCodeCacheSize, \ 1531 "Initial code cache size (in bytes)") \ 1532 constraint(VMPageSizeConstraintFunc, AtParse) \ 1533 \ 1534 develop_pd(uintx, CodeCacheMinimumUseSpace, \ 1535 "Minimum code cache size (in bytes) required to start VM.") \ 1536 range(0, max_uintx) \ 1537 \ 1538 product(bool, SegmentedCodeCache, false, \ 1539 "Use a segmented code cache") \ 1540 \ 1541 product_pd(uintx, ReservedCodeCacheSize, \ 1542 "Reserved code cache size (in bytes) - maximum code cache size") \ 1543 constraint(VMPageSizeConstraintFunc, AtParse) \ 1544 \ 1545 product_pd(uintx, NonProfiledCodeHeapSize, \ 1546 "Size of code heap with non-profiled methods (in bytes)") \ 1547 range(0, max_uintx) \ 1548 \ 1549 product_pd(uintx, ProfiledCodeHeapSize, \ 1550 "Size of code heap with profiled methods (in bytes)") \ 1551 range(0, max_uintx) \ 1552 \ 1553 product_pd(uintx, NonNMethodCodeHeapSize, \ 1554 "Size of code heap with non-nmethods (in bytes)") \ 1555 constraint(VMPageSizeConstraintFunc, AtParse) \ 1556 \ 1557 product_pd(uintx, CodeCacheExpansionSize, \ 1558 "Code cache expansion size (in bytes)") \ 1559 range(32*K, max_uintx) \ 1560 \ 1561 product_pd(uintx, CodeCacheMinBlockLength, DIAGNOSTIC, \ 1562 "Minimum number of segments in a code cache block") \ 1563 range(1, 100) \ 1564 \ 1565 develop(bool, ExitOnFullCodeCache, false, \ 1566 "Exit the VM if we fill the code cache") \ 1567 \ 1568 product(bool, UseCodeCacheFlushing, true, \ 1569 "Remove cold/old nmethods from the code cache") \ 1570 \ 1571 product(double, SweeperThreshold, 15.0, \ 1572 "Threshold when a code cache unloading GC is invoked." \ 1573 "Value is percentage of ReservedCodeCacheSize.") \ 1574 range(0.0, 100.0) \ 1575 \ 1576 product(uintx, StartAggressiveSweepingAt, 10, \ 1577 "Start aggressive sweeping if X[%] of the code cache is free." \ 1578 "Segmented code cache: X[%] of the non-profiled heap." \ 1579 "Non-segmented code cache: X[%] of the total code cache") \ 1580 range(0, 100) \ 1581 \ 1582 /* interpreter debugging */ \ 1583 develop(intx, BinarySwitchThreshold, 5, \ 1584 "Minimal number of lookupswitch entries for rewriting to binary " \ 1585 "switch") \ 1586 \ 1587 develop(intx, StopInterpreterAt, 0, \ 1588 "Stop interpreter execution at specified bytecode number") \ 1589 \ 1590 develop(intx, TraceBytecodesAt, 0, \ 1591 "Trace bytecodes starting with specified bytecode number") \ 1592 \ 1593 develop(intx, TraceBytecodesStopAt, 0, \ 1594 "Stop bytecode tracing at the specified bytecode number") \ 1595 \ 1596 /* Priorities */ \ 1597 product_pd(bool, UseThreadPriorities, "Use native thread priorities") \ 1598 \ 1599 product(int, ThreadPriorityPolicy, 0, \ 1600 "0 : Normal. "\ 1601 " VM chooses priorities that are appropriate for normal "\ 1602 " applications. "\ 1603 " On Windows applications are allowed to use higher native "\ 1604 " priorities. However, with ThreadPriorityPolicy=0, VM will "\ 1605 " not use the highest possible native priority, "\ 1606 " THREAD_PRIORITY_TIME_CRITICAL, as it may interfere with "\ 1607 " system threads. On Linux thread priorities are ignored "\ 1608 " because the OS does not support static priority in "\ 1609 " SCHED_OTHER scheduling class which is the only choice for "\ 1610 " non-root, non-realtime applications. "\ 1611 "1 : Aggressive. "\ 1612 " Java thread priorities map over to the entire range of "\ 1613 " native thread priorities. Higher Java thread priorities map "\ 1614 " to higher native thread priorities. This policy should be "\ 1615 " used with care, as sometimes it can cause performance "\ 1616 " degradation in the application and/or the entire system. On "\ 1617 " Linux/BSD/macOS this policy requires root privilege or an "\ 1618 " extended capability.") \ 1619 range(0, 1) \ 1620 \ 1621 product(bool, ThreadPriorityVerbose, false, \ 1622 "Print priority changes") \ 1623 \ 1624 product(int, CompilerThreadPriority, -1, \ 1625 "The native priority at which compiler threads should run " \ 1626 "(-1 means no change)") \ 1627 range(min_jint, max_jint) \ 1628 \ 1629 product(int, VMThreadPriority, -1, \ 1630 "The native priority at which the VM thread should run " \ 1631 "(-1 means no change)") \ 1632 range(-1, 127) \ 1633 \ 1634 product(int, JavaPriority1_To_OSPriority, -1, \ 1635 "Map Java priorities to OS priorities") \ 1636 range(-1, 127) \ 1637 \ 1638 product(int, JavaPriority2_To_OSPriority, -1, \ 1639 "Map Java priorities to OS priorities") \ 1640 range(-1, 127) \ 1641 \ 1642 product(int, JavaPriority3_To_OSPriority, -1, \ 1643 "Map Java priorities to OS priorities") \ 1644 range(-1, 127) \ 1645 \ 1646 product(int, JavaPriority4_To_OSPriority, -1, \ 1647 "Map Java priorities to OS priorities") \ 1648 range(-1, 127) \ 1649 \ 1650 product(int, JavaPriority5_To_OSPriority, -1, \ 1651 "Map Java priorities to OS priorities") \ 1652 range(-1, 127) \ 1653 \ 1654 product(int, JavaPriority6_To_OSPriority, -1, \ 1655 "Map Java priorities to OS priorities") \ 1656 range(-1, 127) \ 1657 \ 1658 product(int, JavaPriority7_To_OSPriority, -1, \ 1659 "Map Java priorities to OS priorities") \ 1660 range(-1, 127) \ 1661 \ 1662 product(int, JavaPriority8_To_OSPriority, -1, \ 1663 "Map Java priorities to OS priorities") \ 1664 range(-1, 127) \ 1665 \ 1666 product(int, JavaPriority9_To_OSPriority, -1, \ 1667 "Map Java priorities to OS priorities") \ 1668 range(-1, 127) \ 1669 \ 1670 product(int, JavaPriority10_To_OSPriority,-1, \ 1671 "Map Java priorities to OS priorities") \ 1672 range(-1, 127) \ 1673 \ 1674 product(bool, UseCriticalJavaThreadPriority, false, EXPERIMENTAL, \ 1675 "Java thread priority 10 maps to critical scheduling priority") \ 1676 \ 1677 product(bool, UseCriticalCompilerThreadPriority, false, EXPERIMENTAL, \ 1678 "Compiler thread(s) run at critical scheduling priority") \ 1679 \ 1680 develop(intx, NewCodeParameter, 0, \ 1681 "Testing Only: Create a dedicated integer parameter before " \ 1682 "putback") \ 1683 \ 1684 /* new oopmap storage allocation */ \ 1685 develop(intx, MinOopMapAllocation, 8, \ 1686 "Minimum number of OopMap entries in an OopMapSet") \ 1687 \ 1688 /* recompilation */ \ 1689 product_pd(intx, CompileThreshold, \ 1690 "number of interpreted method invocations before (re-)compiling") \ 1691 constraint(CompileThresholdConstraintFunc, AfterErgo) \ 1692 \ 1693 product_pd(bool, TieredCompilation, \ 1694 "Enable tiered compilation") \ 1695 \ 1696 /* Properties for Java libraries */ \ 1697 \ 1698 product(uint64_t, MaxDirectMemorySize, 0, \ 1699 "Maximum total size of NIO direct-buffer allocations. " \ 1700 "Ignored if not explicitly set.") \ 1701 range(0, max_jlong) \ 1702 \ 1703 /* Flags used for temporary code during development */ \ 1704 \ 1705 product(bool, UseNewCode, false, DIAGNOSTIC, \ 1706 "Testing Only: Use the new version while testing") \ 1707 \ 1708 product(bool, UseNewCode2, false, DIAGNOSTIC, \ 1709 "Testing Only: Use the new version while testing") \ 1710 \ 1711 product(bool, UseNewCode3, false, DIAGNOSTIC, \ 1712 "Testing Only: Use the new version while testing") \ 1713 \ 1714 develop(bool, UseDebuggerErgo, false, \ 1715 "Debugging Only: Adjust the VM to be more debugger-friendly. " \ 1716 "Turns on the other UseDebuggerErgo* flags") \ 1717 \ 1718 develop(bool, UseDebuggerErgo1, false, \ 1719 "Debugging Only: Enable workarounds for debugger induced " \ 1720 "os::processor_id() >= os::processor_count() problems") \ 1721 \ 1722 develop(bool, UseDebuggerErgo2, false, \ 1723 "Debugging Only: Limit the number of spawned JVM threads") \ 1724 \ 1725 develop(bool, EnableJVMTIStackDepthAsserts, true, \ 1726 "Enable JVMTI asserts related to stack depth checks") \ 1727 \ 1728 /* flags for performance data collection */ \ 1729 \ 1730 product(bool, UsePerfData, true, \ 1731 "Flag to disable jvmstat instrumentation for performance testing "\ 1732 "and problem isolation purposes") \ 1733 \ 1734 product(bool, PerfDataSaveToFile, false, \ 1735 "Save PerfData memory to hsperfdata_<pid> file on exit") \ 1736 \ 1737 product(ccstr, PerfDataSaveFile, nullptr, \ 1738 "Save PerfData memory to the specified absolute pathname. " \ 1739 "The string %p in the file name (if present) " \ 1740 "will be replaced by pid") \ 1741 \ 1742 product(int, PerfDataSamplingInterval, 50, \ 1743 "Data sampling interval (in milliseconds)") \ 1744 range(PeriodicTask::min_interval, max_jint) \ 1745 constraint(PerfDataSamplingIntervalFunc, AfterErgo) \ 1746 \ 1747 product(bool, PerfDisableSharedMem, false, \ 1748 "Store performance data in standard memory") \ 1749 \ 1750 product(int, PerfDataMemorySize, 64*K, \ 1751 "Size of performance data memory region. Will be rounded " \ 1752 "up to a multiple of the native os page size.") \ 1753 range(128, 32*64*K) \ 1754 \ 1755 product(int, PerfMaxStringConstLength, 1024, \ 1756 "Maximum PerfStringConstant string length before truncation") \ 1757 range(32, 32*K) \ 1758 \ 1759 product(bool, PerfAllowAtExitRegistration, false, \ 1760 "Allow registration of atexit() methods") \ 1761 \ 1762 product(bool, PerfBypassFileSystemCheck, false, \ 1763 "Bypass Win32 file system criteria checks (Windows Only)") \ 1764 \ 1765 product(int, UnguardOnExecutionViolation, 0, \ 1766 "Unguard page and retry on no-execute fault (Win32 only) " \ 1767 "0=off, 1=conservative, 2=aggressive") \ 1768 range(0, 2) \ 1769 \ 1770 /* Serviceability Support */ \ 1771 \ 1772 product(bool, ManagementServer, false, \ 1773 "Create JMX Management Server") \ 1774 \ 1775 product(bool, DisableAttachMechanism, false, \ 1776 "Disable mechanism that allows tools to attach to this VM") \ 1777 \ 1778 product(bool, StartAttachListener, false, \ 1779 "Always start Attach Listener at VM startup") \ 1780 \ 1781 product(bool, EnableDynamicAgentLoading, true, \ 1782 "Allow tools to load agents with the attach mechanism") \ 1783 \ 1784 product(bool, PrintConcurrentLocks, false, MANAGEABLE, \ 1785 "Print java.util.concurrent locks in thread dump") \ 1786 \ 1787 product(bool, PrintMethodHandleStubs, false, DIAGNOSTIC, \ 1788 "Print generated stub code for method handles") \ 1789 \ 1790 product(bool, VerifyMethodHandles, trueInDebug, DIAGNOSTIC, \ 1791 "perform extra checks when constructing method handles") \ 1792 \ 1793 product(bool, ShowHiddenFrames, false, DIAGNOSTIC, \ 1794 "show method handle implementation frames (usually hidden)") \ 1795 \ 1796 product(bool, ShowCarrierFrames, false, DIAGNOSTIC, \ 1797 "show virtual threads' carrier frames in exceptions") \ 1798 \ 1799 product(bool, TrustFinalNonStaticFields, false, EXPERIMENTAL, \ 1800 "trust final non-static declarations for constant folding") \ 1801 \ 1802 product(bool, FoldStableValues, true, DIAGNOSTIC, \ 1803 "Optimize loads from stable fields (marked w/ @Stable)") \ 1804 \ 1805 product(int, UseBootstrapCallInfo, 1, DIAGNOSTIC, \ 1806 "0: when resolving InDy or ConDy, force all BSM arguments to be " \ 1807 "resolved before the bootstrap method is called; 1: when a BSM " \ 1808 "that may accept a BootstrapCallInfo is detected, use that API " \ 1809 "to pass BSM arguments, which allows the BSM to delay their " \ 1810 "resolution; 2+: stress test the BCI API by calling more BSMs " \ 1811 "via that API, instead of with the eagerly-resolved array.") \ 1812 \ 1813 product(bool, PauseAtStartup, false, DIAGNOSTIC, \ 1814 "Causes the VM to pause at startup time and wait for the pause " \ 1815 "file to be removed (default: ./vm.paused.<pid>)") \ 1816 \ 1817 product(ccstr, PauseAtStartupFile, nullptr, DIAGNOSTIC, \ 1818 "The file to create and for whose removal to await when pausing " \ 1819 "at startup. (default: ./vm.paused.<pid>)") \ 1820 \ 1821 product(bool, PauseAtExit, false, DIAGNOSTIC, \ 1822 "Pause and wait for keypress on exit if a debugger is attached") \ 1823 \ 1824 product(bool, DTraceMethodProbes, false, \ 1825 "Enable dtrace tool probes for method-entry and method-exit") \ 1826 \ 1827 product(bool, DTraceAllocProbes, false, \ 1828 "Enable dtrace tool probes for object allocation") \ 1829 \ 1830 product(bool, DTraceMonitorProbes, false, \ 1831 "Enable dtrace tool probes for monitor events") \ 1832 \ 1833 product(bool, RelaxAccessControlCheck, false, \ 1834 "Relax the access control checks in the verifier") \ 1835 \ 1836 product(uintx, StringTableSize, defaultStringTableSize, \ 1837 "Number of buckets in the interned String table " \ 1838 "(will be rounded to nearest higher power of 2)") \ 1839 range(minimumStringTableSize, 16777216ul /* 2^24 */) \ 1840 \ 1841 product(uintx, SymbolTableSize, defaultSymbolTableSize, EXPERIMENTAL, \ 1842 "Number of buckets in the JVM internal Symbol table") \ 1843 range(minimumSymbolTableSize, 16777216ul /* 2^24 */) \ 1844 \ 1845 product(bool, UseStringDeduplication, false, \ 1846 "Use string deduplication") \ 1847 \ 1848 product(uint, StringDeduplicationAgeThreshold, 3, \ 1849 "A string must reach this age (or be promoted to an old region) " \ 1850 "to be considered for deduplication") \ 1851 range(1, markWord::max_age) \ 1852 \ 1853 product(size_t, StringDeduplicationInitialTableSize, 500, EXPERIMENTAL, \ 1854 "Approximate initial number of buckets in the table") \ 1855 range(1, 1 * G) \ 1856 \ 1857 product(double, StringDeduplicationGrowTableLoad, 14.0, EXPERIMENTAL, \ 1858 "Entries per bucket above which the table should be expanded") \ 1859 range(0.1, 1000.0) \ 1860 \ 1861 product(double, StringDeduplicationShrinkTableLoad, 1.0, EXPERIMENTAL, \ 1862 "Entries per bucket below which the table should be shrunk") \ 1863 range(0.01, 100.0) \ 1864 \ 1865 product(double, StringDeduplicationTargetTableLoad, 7.0, EXPERIMENTAL, \ 1866 "Desired entries per bucket when resizing the table") \ 1867 range(0.01, 1000.0) \ 1868 \ 1869 product(size_t, StringDeduplicationCleanupDeadMinimum, 100, EXPERIMENTAL, \ 1870 "Minimum number of dead table entries for cleaning the table") \ 1871 \ 1872 product(int, StringDeduplicationCleanupDeadPercent, 5, EXPERIMENTAL, \ 1873 "Minimum percentage of dead table entries for cleaning the table") \ 1874 range(1, 100) \ 1875 \ 1876 product(bool, StringDeduplicationResizeALot, false, DIAGNOSTIC, \ 1877 "Force more frequent table resizing") \ 1878 \ 1879 product(uint64_t, StringDeduplicationHashSeed, 0, DIAGNOSTIC, \ 1880 "Seed for the table hashing function; 0 requests computed seed") \ 1881 \ 1882 product(bool, WhiteBoxAPI, false, DIAGNOSTIC, \ 1883 "Enable internal testing APIs") \ 1884 \ 1885 product(bool, AlwaysAtomicAccesses, false, EXPERIMENTAL, \ 1886 "Accesses to all variables should always be atomic") \ 1887 \ 1888 product(bool, UseUnalignedAccesses, false, DIAGNOSTIC, \ 1889 "Use unaligned memory accesses in Unsafe") \ 1890 \ 1891 product_pd(bool, PreserveFramePointer, \ 1892 "Use the FP register for holding the frame pointer " \ 1893 "and not as a general purpose register.") \ 1894 \ 1895 product(size_t, AsyncLogBufferSize, 2*M, \ 1896 "Memory budget (in bytes) for the buffer of Asynchronous " \ 1897 "Logging (-Xlog:async).") \ 1898 range(100*K, 50*M) \ 1899 \ 1900 product(bool, CheckIntrinsics, true, DIAGNOSTIC, \ 1901 "When a class C is loaded, check that " \ 1902 "(1) all intrinsics defined by the VM for class C are present "\ 1903 "in the loaded class file and are marked with the " \ 1904 "@IntrinsicCandidate annotation, that " \ 1905 "(2) there is an intrinsic registered for all loaded methods " \ 1906 "that are annotated with the @IntrinsicCandidate annotation, " \ 1907 "and that " \ 1908 "(3) no orphan methods exist for class C (i.e., methods for " \ 1909 "which the VM declares an intrinsic but that are not declared "\ 1910 "in the loaded class C. " \ 1911 "Check (3) is available only in debug builds.") \ 1912 \ 1913 product_pd(intx, InitArrayShortSize, DIAGNOSTIC, \ 1914 "Threshold small size (in bytes) for clearing arrays. " \ 1915 "Anything this size or smaller may get converted to discrete " \ 1916 "scalar stores.") \ 1917 range(0, max_intx) \ 1918 constraint(InitArrayShortSizeConstraintFunc, AfterErgo) \ 1919 \ 1920 product(ccstr, AllocateHeapAt, nullptr, \ 1921 "Path to the directory where a temporary file will be created " \ 1922 "to use as the backing store for Java Heap.") \ 1923 \ 1924 product_pd(bool, VMContinuations, EXPERIMENTAL, \ 1925 "Enable VM continuations support") \ 1926 \ 1927 develop(bool, LoomDeoptAfterThaw, false, \ 1928 "Deopt stack after thaw") \ 1929 \ 1930 develop(bool, LoomVerifyAfterThaw, false, \ 1931 "Verify stack after thaw") \ 1932 \ 1933 develop(bool, VerifyContinuations, false, \ 1934 "Verify continuation consistency") \ 1935 \ 1936 develop(bool, UseContinuationFastPath, true, \ 1937 "Use fast-path frame walking in continuations") \ 1938 \ 1939 develop(int, VerifyMetaspaceInterval, DEBUG_ONLY(500) NOT_DEBUG(0), \ 1940 "Run periodic metaspace verifications (0 - none, " \ 1941 "1 - always, >1 every nth interval)") \ 1942 \ 1943 product(bool, ShowRegistersOnAssert, true, DIAGNOSTIC, \ 1944 "On internal errors, include registers in error report.") \ 1945 \ 1946 product(bool, UseSwitchProfiling, true, DIAGNOSTIC, \ 1947 "leverage profiling for table/lookup switch") \ 1948 \ 1949 develop(bool, TraceMemoryWriteback, false, \ 1950 "Trace memory writeback operations") \ 1951 \ 1952 JFR_ONLY(product(bool, FlightRecorder, false, \ 1953 "(Deprecated) Enable Flight Recorder")) \ 1954 \ 1955 JFR_ONLY(product(ccstr, FlightRecorderOptions, nullptr, \ 1956 "Flight Recorder options")) \ 1957 \ 1958 JFR_ONLY(product(ccstr, StartFlightRecording, nullptr, \ 1959 "Start flight recording with options")) \ 1960 \ 1961 product(bool, UseFastUnorderedTimeStamps, false, EXPERIMENTAL, \ 1962 "Use platform unstable time where supported for timestamps only") \ 1963 \ 1964 product(bool, UseEmptySlotsInSupers, true, \ 1965 "(Deprecated) Allow allocating fields in empty slots of " \ 1966 "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 product(bool, ProfileVMLocks, false, DIAGNOSTIC, \ 1991 "Profile VM locks usage on main thread") \ 1992 \ 1993 product(bool, ProfileVMCalls, false, DIAGNOSTIC, \ 1994 "Profile VM calls on main thread") \ 1995 \ 1996 product(bool, ProfileVMOps, true, DIAGNOSTIC, \ 1997 "Profile VM operations on main thread") \ 1998 \ 1999 product(bool, ProfileRuntimeCalls, false, DIAGNOSTIC, \ 2000 "Profile calls into VM runtime on main thread") \ 2001 \ 2002 develop(bool, SimulateFullAddressSpace, false, \ 2003 "Simulates a very populated, fragmented address space; no " \ 2004 "targeted reservations will succeed.") \ 2005 \ 2006 product(bool, ProfileExceptionHandlers, true, \ 2007 "Profile exception handlers") \ 2008 \ 2009 product(bool, AlwaysRecordEvolDependencies, true, EXPERIMENTAL, \ 2010 "Unconditionally record nmethod dependencies on class " \ 2011 "rewriting/transformation independently of the JVMTI " \ 2012 "can_{retransform/redefine}_classes capabilities.") \ 2013 \ 2014 product(bool, TraceThreadTime, false, \ 2015 "Enable tracing of thread time in Perf counters") \ 2016 \ 2017 product(bool, UseSecondarySupersCache, true, DIAGNOSTIC, \ 2018 "Use secondary supers cache during subtype checks.") \ 2019 \ 2020 product(bool, UseSecondarySupersTable, false, DIAGNOSTIC, \ 2021 "Use hash table to lookup secondary supers.") \ 2022 \ 2023 product(bool, VerifySecondarySupers, false, DIAGNOSTIC, \ 2024 "Check that linear and hashed secondary lookups return the same result.") \ 2025 \ 2026 product(bool, StressSecondarySupers, false, DIAGNOSTIC, \ 2027 "Use a terrible hash function in order to generate many collisions.") \ 2028 2029 2030 // end of RUNTIME_FLAGS 2031 2032 DECLARE_FLAGS(LP64_RUNTIME_FLAGS) 2033 DECLARE_ARCH_FLAGS(ARCH_FLAGS) 2034 DECLARE_FLAGS(RUNTIME_FLAGS) 2035 DECLARE_FLAGS(RUNTIME_OS_FLAGS) 2036 2037 #endif // SHARE_RUNTIME_GLOBALS_HPP