1 /* 2 * Copyright (c) 1997, 2022, Oracle and/or its affiliates. All rights reserved. 3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. 4 * 5 * This code is free software; you can redistribute it and/or modify it 6 * under the terms of the GNU General Public License version 2 only, as 7 * published by the Free Software Foundation. 8 * 9 * This code is distributed in the hope that it will be useful, but WITHOUT 10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 12 * version 2 for more details (a copy is included in the LICENSE file that 13 * accompanied this code). 14 * 15 * You should have received a copy of the GNU General Public License version 16 * 2 along with this work; if not, write to the Free Software Foundation, 17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. 18 * 19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA 20 * or visit www.oracle.com if you need additional information or have any 21 * questions. 22 * 23 */ 24 25 #ifndef SHARE_RUNTIME_GLOBALS_HPP 26 #define SHARE_RUNTIME_GLOBALS_HPP 27 28 #include "compiler/compiler_globals_pd.hpp" 29 #include "runtime/globals_shared.hpp" 30 #include "utilities/align.hpp" 31 #include "utilities/globalDefinitions.hpp" 32 #include "utilities/macros.hpp" 33 #include CPU_HEADER(globals) 34 #include OS_HEADER(globals) 35 #include OS_CPU_HEADER(globals) 36 37 // develop flags are settable / visible only during development and are constant in the PRODUCT version 38 // product flags are always settable / visible 39 // notproduct flags are settable / visible only during development and are not declared in the PRODUCT version 40 // develop_pd/product_pd flags are the same as develop/product, except that their default values 41 // are specified in platform-dependent header files. 42 43 // Flags must be declared with the following number of parameters: 44 // non-pd flags: 45 // (type, name, default_value, doc), or 46 // (type, name, default_value, extra_attrs, doc) 47 // pd flags: 48 // (type, name, doc), or 49 // (type, name, extra_attrs, doc) 50 51 // A flag must be declared with one of the following types: 52 // bool, int, uint, intx, uintx, size_t, ccstr, ccstrlist, double, or uint64_t. 53 // The type "ccstr" and "ccstrlist" are an alias for "const char*" and is used 54 // only in this file, because the macrology requires single-token type names. 55 56 // The optional extra_attrs parameter may have one of the following values: 57 // DIAGNOSTIC, EXPERIMENTAL, or MANAGEABLE. Currently extra_attrs can be used 58 // only with product/product_pd flags. 59 // 60 // DIAGNOSTIC options are not meant for VM tuning or for product modes. 61 // They are to be used for VM quality assurance or field diagnosis 62 // of VM bugs. They are hidden so that users will not be encouraged to 63 // try them as if they were VM ordinary execution options. However, they 64 // are available in the product version of the VM. Under instruction 65 // from support engineers, VM customers can turn them on to collect 66 // diagnostic information about VM problems. To use a VM diagnostic 67 // option, you must first specify +UnlockDiagnosticVMOptions. 68 // (This master switch also affects the behavior of -Xprintflags.) 69 // 70 // EXPERIMENTAL flags are in support of features that are not 71 // part of the officially supported product, but are available 72 // for experimenting with. They could, for example, be performance 73 // features that may not have undergone full or rigorous QA, but which may 74 // help performance in some cases and released for experimentation 75 // by the community of users and developers. This flag also allows one to 76 // be able to build a fully supported product that nonetheless also 77 // ships with some unsupported, lightly tested, experimental features. 78 // Like the UnlockDiagnosticVMOptions flag above, there is a corresponding 79 // UnlockExperimentalVMOptions flag, which allows the control and 80 // modification of the experimental flags. 81 // 82 // Nota bene: neither diagnostic nor experimental options should be used casually, 83 // and they are not supported on production loads, except under explicit 84 // direction from support engineers. 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 notproduct, \ 121 range, \ 122 constraint) \ 123 \ 124 product(bool, UseCompressedOops, false, \ 125 "Use 32-bit object references in 64-bit VM. " \ 126 "lp64_product means flag is always constant in 32 bit VM") \ 127 \ 128 product(bool, UseCompressedClassPointers, false, \ 129 "Use 32-bit class pointers in 64-bit VM. " \ 130 "lp64_product means flag is always constant in 32 bit VM") \ 131 \ 132 product(int, ObjectAlignmentInBytes, 8, \ 133 "Default object alignment in bytes, 8 is minimum") \ 134 range(8, 256) \ 135 constraint(ObjectAlignmentInBytesConstraintFunc, AtParse) 136 137 #else 138 // !_LP64 139 140 #define LP64_RUNTIME_FLAGS(develop, \ 141 develop_pd, \ 142 product, \ 143 product_pd, \ 144 notproduct, \ 145 range, \ 146 constraint) 147 const bool UseCompressedOops = false; 148 const bool UseCompressedClassPointers = false; 149 const int ObjectAlignmentInBytes = 8; 150 151 #endif // _LP64 152 153 #define RUNTIME_FLAGS(develop, \ 154 develop_pd, \ 155 product, \ 156 product_pd, \ 157 notproduct, \ 158 range, \ 159 constraint) \ 160 \ 161 notproduct(bool, CheckCompressedOops, true, \ 162 "Generate checks in encoding/decoding code in debug VM") \ 163 \ 164 product(uintx, HeapSearchSteps, 3 PPC64_ONLY(+17), \ 165 "Heap allocation steps through preferred address regions to find" \ 166 " where it can allocate the heap. Number of steps to take per " \ 167 "region.") \ 168 range(1, max_uintx) \ 169 \ 170 product(uint, HandshakeTimeout, 0, DIAGNOSTIC, \ 171 "If nonzero set a timeout in milliseconds for handshakes") \ 172 \ 173 product(bool, AlwaysSafeConstructors, false, EXPERIMENTAL, \ 174 "Force safe construction, as if all fields are final.") \ 175 \ 176 product(bool, UnlockDiagnosticVMOptions, trueInDebug, DIAGNOSTIC, \ 177 "Enable normal processing of flags relating to field diagnostics")\ 178 \ 179 product(bool, UnlockExperimentalVMOptions, false, EXPERIMENTAL, \ 180 "Enable normal processing of flags relating to experimental " \ 181 "features") \ 182 \ 183 product(bool, JavaMonitorsInStackTrace, true, \ 184 "Print information about Java monitor locks when the stacks are " \ 185 "dumped") \ 186 \ 187 product_pd(bool, UseLargePages, \ 188 "Use large page memory") \ 189 \ 190 product_pd(bool, UseLargePagesIndividualAllocation, \ 191 "Allocate large pages individually for better affinity") \ 192 \ 193 develop(bool, LargePagesIndividualAllocationInjectError, false, \ 194 "Fail large pages individual allocation") \ 195 \ 196 product(bool, UseNUMA, false, \ 197 "Use NUMA if available") \ 198 \ 199 product(bool, UseNUMAInterleaving, false, \ 200 "Interleave memory across NUMA nodes if available") \ 201 \ 202 product(size_t, NUMAInterleaveGranularity, 2*M, \ 203 "Granularity to use for NUMA interleaving on Windows OS") \ 204 constraint(NUMAInterleaveGranularityConstraintFunc, AtParse) \ 205 \ 206 product(uintx, NUMAChunkResizeWeight, 20, \ 207 "Percentage (0-100) used to weight the current sample when " \ 208 "computing exponentially decaying average for " \ 209 "AdaptiveNUMAChunkSizing") \ 210 range(0, 100) \ 211 \ 212 product(size_t, NUMASpaceResizeRate, 1*G, \ 213 "Do not reallocate more than this amount per collection") \ 214 range(0, max_uintx) \ 215 \ 216 product(bool, UseAdaptiveNUMAChunkSizing, true, \ 217 "Enable adaptive chunk sizing for NUMA") \ 218 \ 219 product(bool, NUMAStats, false, \ 220 "Print NUMA stats in detailed heap information") \ 221 \ 222 product(uintx, NUMAPageScanRate, 256, \ 223 "Maximum number of pages to include in the page scan procedure") \ 224 range(0, max_uintx) \ 225 \ 226 product(bool, UseAES, false, \ 227 "Control whether AES instructions are used when available") \ 228 \ 229 product(bool, UseFMA, false, \ 230 "Control whether FMA instructions are used when available") \ 231 \ 232 product(bool, UseSHA, false, \ 233 "Control whether SHA instructions are used when available") \ 234 \ 235 product(bool, UseGHASHIntrinsics, false, DIAGNOSTIC, \ 236 "Use intrinsics for GHASH versions of crypto") \ 237 \ 238 product(bool, UseBASE64Intrinsics, false, \ 239 "Use intrinsics for java.util.Base64") \ 240 \ 241 product(bool, UsePoly1305Intrinsics, false, DIAGNOSTIC, \ 242 "Use intrinsics for sun.security.util.math.intpoly") \ 243 \ 244 product(size_t, LargePageSizeInBytes, 0, \ 245 "Maximum large page size used (0 will use the default large " \ 246 "page size for the environment as the maximum)") \ 247 range(0, max_uintx) \ 248 \ 249 product(size_t, LargePageHeapSizeThreshold, 128*M, \ 250 "Use large pages if maximum heap is at least this big") \ 251 range(0, max_uintx) \ 252 \ 253 product(bool, ForceTimeHighResolution, false, \ 254 "Using high time resolution (for Win32 only)") \ 255 \ 256 develop(bool, TracePcPatching, false, \ 257 "Trace usage of frame::patch_pc") \ 258 \ 259 develop(bool, TraceRelocator, false, \ 260 "Trace the bytecode relocator") \ 261 \ 262 \ 263 product(bool, SafepointALot, false, DIAGNOSTIC, \ 264 "Generate a lot of safepoints. This works with " \ 265 "GuaranteedSafepointInterval") \ 266 \ 267 product(bool, HandshakeALot, false, DIAGNOSTIC, \ 268 "Generate a lot of handshakes. This works with " \ 269 "GuaranteedSafepointInterval") \ 270 \ 271 product_pd(bool, BackgroundCompilation, \ 272 "A thread requesting compilation is not blocked during " \ 273 "compilation") \ 274 \ 275 product(bool, MethodFlushing, true, \ 276 "Reclamation of compiled methods") \ 277 \ 278 develop(bool, VerifyStack, false, \ 279 "Verify stack of each thread when it is entering a runtime call") \ 280 \ 281 product(bool, ForceUnreachable, false, DIAGNOSTIC, \ 282 "Make all non code cache addresses to be unreachable by " \ 283 "forcing use of 64bit literal fixups") \ 284 \ 285 develop(bool, TraceDerivedPointers, false, \ 286 "Trace traversal of derived pointers on stack") \ 287 \ 288 notproduct(bool, TraceCodeBlobStacks, false, \ 289 "Trace stack-walk of codeblobs") \ 290 \ 291 notproduct(bool, PrintRewrites, false, \ 292 "Print methods that are being rewritten") \ 293 \ 294 product(bool, UseInlineCaches, true, \ 295 "Use Inline Caches for virtual calls ") \ 296 \ 297 product(bool, InlineArrayCopy, true, DIAGNOSTIC, \ 298 "Inline arraycopy native that is known to be part of " \ 299 "base library DLL") \ 300 \ 301 product(bool, InlineObjectHash, true, DIAGNOSTIC, \ 302 "Inline Object::hashCode() native that is known to be part " \ 303 "of base library DLL") \ 304 \ 305 product(bool, InlineNatives, true, DIAGNOSTIC, \ 306 "Inline natives that are known to be part of base library DLL") \ 307 \ 308 product(bool, InlineMathNatives, true, DIAGNOSTIC, \ 309 "Inline SinD, CosD, etc.") \ 310 \ 311 product(bool, InlineClassNatives, true, DIAGNOSTIC, \ 312 "Inline Class.isInstance, etc") \ 313 \ 314 product(bool, InlineThreadNatives, true, DIAGNOSTIC, \ 315 "Inline Thread.currentThread, etc") \ 316 \ 317 product(bool, InlineUnsafeOps, true, DIAGNOSTIC, \ 318 "Inline memory ops (native methods) from Unsafe") \ 319 \ 320 product(bool, UseAESIntrinsics, false, DIAGNOSTIC, \ 321 "Use intrinsics for AES versions of crypto") \ 322 \ 323 product(bool, UseAESCTRIntrinsics, false, DIAGNOSTIC, \ 324 "Use intrinsics for the paralleled version of AES/CTR crypto") \ 325 \ 326 product(bool, UseChaCha20Intrinsics, false, DIAGNOSTIC, \ 327 "Use intrinsics for the vectorized version of ChaCha20") \ 328 \ 329 product(bool, UseMD5Intrinsics, false, DIAGNOSTIC, \ 330 "Use intrinsics for MD5 crypto hash function") \ 331 \ 332 product(bool, UseSHA1Intrinsics, false, DIAGNOSTIC, \ 333 "Use intrinsics for SHA-1 crypto hash function. " \ 334 "Requires that UseSHA is enabled.") \ 335 \ 336 product(bool, UseSHA256Intrinsics, false, DIAGNOSTIC, \ 337 "Use intrinsics for SHA-224 and SHA-256 crypto hash functions. " \ 338 "Requires that UseSHA is enabled.") \ 339 \ 340 product(bool, UseSHA512Intrinsics, false, DIAGNOSTIC, \ 341 "Use intrinsics for SHA-384 and SHA-512 crypto hash functions. " \ 342 "Requires that UseSHA is enabled.") \ 343 \ 344 product(bool, UseSHA3Intrinsics, false, DIAGNOSTIC, \ 345 "Use intrinsics for SHA3 crypto hash function. " \ 346 "Requires that UseSHA is enabled.") \ 347 \ 348 product(bool, UseCRC32Intrinsics, false, DIAGNOSTIC, \ 349 "use intrinsics for java.util.zip.CRC32") \ 350 \ 351 product(bool, UseCRC32CIntrinsics, false, DIAGNOSTIC, \ 352 "use intrinsics for java.util.zip.CRC32C") \ 353 \ 354 product(bool, UseAdler32Intrinsics, false, DIAGNOSTIC, \ 355 "use intrinsics for java.util.zip.Adler32") \ 356 \ 357 product(bool, UseVectorizedMismatchIntrinsic, false, DIAGNOSTIC, \ 358 "Enables intrinsification of ArraysSupport.vectorizedMismatch()") \ 359 \ 360 product(bool, UseCopySignIntrinsic, false, DIAGNOSTIC, \ 361 "Enables intrinsification of Math.copySign") \ 362 \ 363 product(bool, UseSignumIntrinsic, false, DIAGNOSTIC, \ 364 "Enables intrinsification of Math.signum") \ 365 \ 366 product(ccstrlist, DisableIntrinsic, "", DIAGNOSTIC, \ 367 "do not expand intrinsics whose (internal) names appear here") \ 368 constraint(DisableIntrinsicConstraintFunc,AfterErgo) \ 369 \ 370 product(ccstrlist, ControlIntrinsic, "", DIAGNOSTIC, \ 371 "Control intrinsics using a list of +/- (internal) names, " \ 372 "separated by commas") \ 373 constraint(ControlIntrinsicConstraintFunc,AfterErgo) \ 374 \ 375 develop(bool, TraceCallFixup, false, \ 376 "Trace all call fixups") \ 377 \ 378 develop(bool, DeoptimizeALot, false, \ 379 "Deoptimize at every exit from the runtime system") \ 380 \ 381 notproduct(ccstrlist, DeoptimizeOnlyAt, "", \ 382 "A comma separated list of bcis to deoptimize at") \ 383 \ 384 develop(bool, DeoptimizeRandom, false, \ 385 "Deoptimize random frames on random exit from the runtime system")\ 386 \ 387 notproduct(bool, ZombieALot, false, \ 388 "Create non-entrant nmethods at exit from the runtime system") \ 389 \ 390 notproduct(bool, WalkStackALot, false, \ 391 "Trace stack (no print) at every exit from the runtime system") \ 392 \ 393 develop(bool, DeoptimizeObjectsALot, false, \ 394 "For testing purposes concurrent threads revert optimizations " \ 395 "based on escape analysis at intervals given with " \ 396 "DeoptimizeObjectsALotInterval=n. The thread count is given " \ 397 "with DeoptimizeObjectsALotThreadCountSingle and " \ 398 "DeoptimizeObjectsALotThreadCountAll.") \ 399 \ 400 develop(uint64_t, DeoptimizeObjectsALotInterval, 5, \ 401 "Interval for DeoptimizeObjectsALot.") \ 402 range(0, max_jlong) \ 403 \ 404 develop(int, DeoptimizeObjectsALotThreadCountSingle, 1, \ 405 "The number of threads that revert optimizations based on " \ 406 "escape analysis for a single thread if DeoptimizeObjectsALot " \ 407 "is enabled. The target thread is selected round robin." ) \ 408 range(0, max_jint) \ 409 \ 410 develop(int, DeoptimizeObjectsALotThreadCountAll, 1, \ 411 "The number of threads that revert optimizations based on " \ 412 "escape analysis for all threads if DeoptimizeObjectsALot " \ 413 "is enabled." ) \ 414 range(0, max_jint) \ 415 \ 416 notproduct(bool, VerifyLastFrame, false, \ 417 "Verify oops on last frame on entry to VM") \ 418 \ 419 product(bool, SafepointTimeout, false, \ 420 "Time out and warn or fail after SafepointTimeoutDelay " \ 421 "milliseconds if failed to reach safepoint") \ 422 \ 423 product(bool, AbortVMOnSafepointTimeout, false, DIAGNOSTIC, \ 424 "Abort upon failure to reach safepoint (see SafepointTimeout)") \ 425 \ 426 product(bool, AbortVMOnVMOperationTimeout, false, DIAGNOSTIC, \ 427 "Abort upon failure to complete VM operation promptly") \ 428 \ 429 product(intx, AbortVMOnVMOperationTimeoutDelay, 1000, DIAGNOSTIC, \ 430 "Delay in milliseconds for option AbortVMOnVMOperationTimeout") \ 431 range(0, max_intx) \ 432 \ 433 product(bool, MaxFDLimit, true, \ 434 "Bump the number of file descriptors to maximum (Unix only)") \ 435 \ 436 product(bool, LogEvents, true, DIAGNOSTIC, \ 437 "Enable the various ring buffer event logs") \ 438 \ 439 product(uintx, LogEventsBufferEntries, 20, DIAGNOSTIC, \ 440 "Number of ring buffer event logs") \ 441 range(1, NOT_LP64(1*K) LP64_ONLY(1*M)) \ 442 \ 443 product(bool, BytecodeVerificationRemote, true, DIAGNOSTIC, \ 444 "Enable the Java bytecode verifier for remote classes") \ 445 \ 446 product(bool, BytecodeVerificationLocal, false, DIAGNOSTIC, \ 447 "Enable the Java bytecode verifier for local classes") \ 448 \ 449 develop(bool, VerifyStackAtCalls, false, \ 450 "Verify that the stack pointer is unchanged after calls") \ 451 \ 452 develop(bool, TraceJavaAssertions, false, \ 453 "Trace java language assertions") \ 454 \ 455 notproduct(bool, VerifyCodeCache, false, \ 456 "Verify code cache on memory allocation/deallocation") \ 457 \ 458 develop(bool, ZapResourceArea, trueInDebug, \ 459 "Zap freed resource/arena space") \ 460 \ 461 notproduct(bool, ZapVMHandleArea, trueInDebug, \ 462 "Zap freed VM handle space") \ 463 \ 464 notproduct(bool, ZapStackSegments, trueInDebug, \ 465 "Zap allocated/freed stack segments") \ 466 \ 467 develop(bool, ZapUnusedHeapArea, trueInDebug, \ 468 "Zap unused heap space") \ 469 \ 470 develop(bool, CheckZapUnusedHeapArea, false, \ 471 "Check zapping of unused heap space") \ 472 \ 473 develop(bool, ZapFillerObjects, trueInDebug, \ 474 "Zap filler objects") \ 475 \ 476 product(bool, ExecutingUnitTests, false, \ 477 "Whether the JVM is running unit tests or not") \ 478 \ 479 develop(uint, ErrorHandlerTest, 0, \ 480 "If > 0, provokes an error after VM initialization; the value " \ 481 "determines which error to provoke. See controlled_crash() " \ 482 "in vmError.cpp.") \ 483 range(0, 17) \ 484 \ 485 develop(uint, TestCrashInErrorHandler, 0, \ 486 "If > 0, provokes an error inside VM error handler (a secondary " \ 487 "crash). see controlled_crash() in vmError.cpp") \ 488 range(0, 17) \ 489 \ 490 develop(bool, TestSafeFetchInErrorHandler, false , \ 491 "If true, tests SafeFetch inside error handler.") \ 492 \ 493 develop(bool, TestUnresponsiveErrorHandler, false, \ 494 "If true, simulates an unresponsive error handler.") \ 495 \ 496 develop(bool, Verbose, false, \ 497 "Print additional debugging information from other modes") \ 498 \ 499 develop(bool, PrintMiscellaneous, false, \ 500 "Print uncategorized debugging information (requires +Verbose)") \ 501 \ 502 develop(bool, WizardMode, false, \ 503 "Print much more debugging information") \ 504 \ 505 product(bool, ShowMessageBoxOnError, false, \ 506 "Keep process alive on VM fatal error") \ 507 \ 508 product(bool, CreateCoredumpOnCrash, true, \ 509 "Create core/mini dump on VM fatal error") \ 510 \ 511 product(uint64_t, ErrorLogTimeout, 2 * 60, \ 512 "Timeout, in seconds, to limit the time spent on writing an " \ 513 "error log in case of a crash.") \ 514 range(0, (uint64_t)max_jlong/1000) \ 515 \ 516 product(bool, ErrorLogSecondaryErrorDetails, false, DIAGNOSTIC, \ 517 "If enabled, show details on secondary crashes in the error log") \ 518 \ 519 develop(intx, TraceDwarfLevel, 0, \ 520 "Debug levels for the dwarf parser") \ 521 range(0, 4) \ 522 \ 523 product(bool, SuppressFatalErrorMessage, false, \ 524 "Report NO fatal error message (avoid deadlock)") \ 525 \ 526 product(ccstrlist, OnError, "", \ 527 "Run user-defined commands on fatal error; see VMError.cpp " \ 528 "for examples") \ 529 \ 530 product(ccstrlist, OnOutOfMemoryError, "", \ 531 "Run user-defined commands on first java.lang.OutOfMemoryError " \ 532 "thrown from JVM") \ 533 \ 534 product(bool, HeapDumpBeforeFullGC, false, MANAGEABLE, \ 535 "Dump heap to file before any major stop-the-world GC") \ 536 \ 537 product(bool, HeapDumpAfterFullGC, false, MANAGEABLE, \ 538 "Dump heap to file after any major stop-the-world GC") \ 539 \ 540 product(bool, HeapDumpOnOutOfMemoryError, false, MANAGEABLE, \ 541 "Dump heap to file when java.lang.OutOfMemoryError is thrown " \ 542 "from JVM") \ 543 \ 544 product(ccstr, HeapDumpPath, NULL, MANAGEABLE, \ 545 "When HeapDumpOnOutOfMemoryError is on, the path (filename or " \ 546 "directory) of the dump file (defaults to java_pid<pid>.hprof " \ 547 "in the working directory)") \ 548 \ 549 product(intx, HeapDumpGzipLevel, 0, MANAGEABLE, \ 550 "When HeapDumpOnOutOfMemoryError is on, the gzip compression " \ 551 "level of the dump file. 0 (the default) disables gzip " \ 552 "compression. Otherwise the level must be between 1 and 9.") \ 553 range(0, 9) \ 554 \ 555 product(ccstr, NativeMemoryTracking, DEBUG_ONLY("summary") NOT_DEBUG("off"), \ 556 "Native memory tracking options") \ 557 \ 558 product(bool, PrintNMTStatistics, false, DIAGNOSTIC, \ 559 "Print native memory tracking summary data if it is on") \ 560 \ 561 product(bool, LogCompilation, false, DIAGNOSTIC, \ 562 "Log compilation activity in detail to LogFile") \ 563 \ 564 product(bool, PrintCompilation, false, \ 565 "Print compilations") \ 566 \ 567 product(intx, RepeatCompilation, 0, DIAGNOSTIC, \ 568 "Repeat compilation without installing code (number of times)") \ 569 range(0, max_jint) \ 570 \ 571 product(bool, PrintExtendedThreadInfo, false, \ 572 "Print more information in thread dump") \ 573 \ 574 product(intx, ScavengeRootsInCode, 2, DIAGNOSTIC, \ 575 "0: do not allow scavengable oops in the code cache; " \ 576 "1: allow scavenging from the code cache; " \ 577 "2: emit as many constants as the compiler can see") \ 578 range(0, 2) \ 579 \ 580 product(bool, AlwaysRestoreFPU, false, \ 581 "Restore the FPU control word after every JNI call (expensive)") \ 582 \ 583 product(bool, PrintCompilation2, false, DIAGNOSTIC, \ 584 "Print additional statistics per compilation") \ 585 \ 586 product(bool, PrintAdapterHandlers, false, DIAGNOSTIC, \ 587 "Print code generated for i2c/c2i adapters") \ 588 \ 589 product(bool, VerifyAdapterCalls, trueInDebug, DIAGNOSTIC, \ 590 "Verify that i2c/c2i adapters are called properly") \ 591 \ 592 develop(bool, VerifyAdapterSharing, false, \ 593 "Verify that the code for shared adapters is the equivalent") \ 594 \ 595 product(bool, PrintAssembly, false, DIAGNOSTIC, \ 596 "Print assembly code (using external disassembler.so)") \ 597 \ 598 product(ccstr, PrintAssemblyOptions, NULL, DIAGNOSTIC, \ 599 "Print options string passed to disassembler.so") \ 600 \ 601 notproduct(bool, PrintNMethodStatistics, false, \ 602 "Print a summary statistic for the generated nmethods") \ 603 \ 604 product(bool, PrintNMethods, false, DIAGNOSTIC, \ 605 "Print assembly code for nmethods when generated") \ 606 \ 607 product(bool, PrintNativeNMethods, false, DIAGNOSTIC, \ 608 "Print assembly code for native nmethods when generated") \ 609 \ 610 develop(bool, PrintDebugInfo, false, \ 611 "Print debug information for all nmethods when generated") \ 612 \ 613 develop(bool, PrintRelocations, false, \ 614 "Print relocation information for all nmethods when generated") \ 615 \ 616 develop(bool, PrintDependencies, false, \ 617 "Print dependency information for all nmethods when generated") \ 618 \ 619 develop(bool, PrintExceptionHandlers, false, \ 620 "Print exception handler tables for all nmethods when generated") \ 621 \ 622 develop(bool, StressCompiledExceptionHandlers, false, \ 623 "Exercise compiled exception handlers") \ 624 \ 625 develop(bool, InterceptOSException, false, \ 626 "Start debugger when an implicit OS (e.g. NULL) " \ 627 "exception happens") \ 628 \ 629 product(bool, PrintCodeCache, false, \ 630 "Print the code cache memory usage when exiting") \ 631 \ 632 develop(bool, PrintCodeCache2, false, \ 633 "Print detailed usage information on the code cache when exiting")\ 634 \ 635 product(bool, PrintCodeCacheOnCompilation, false, \ 636 "Print the code cache memory usage each time a method is " \ 637 "compiled") \ 638 \ 639 product(bool, PrintCodeHeapAnalytics, false, DIAGNOSTIC, \ 640 "Print code heap usage statistics on exit and on full condition") \ 641 \ 642 product(bool, PrintStubCode, false, DIAGNOSTIC, \ 643 "Print generated stub code") \ 644 \ 645 product(bool, StackTraceInThrowable, true, \ 646 "Collect backtrace in throwable when exception happens") \ 647 \ 648 product(bool, OmitStackTraceInFastThrow, true, \ 649 "Omit backtraces for some 'hot' exceptions in optimized code") \ 650 \ 651 product(bool, ShowCodeDetailsInExceptionMessages, true, MANAGEABLE, \ 652 "Show exception messages from RuntimeExceptions that contain " \ 653 "snippets of the failing code. Disable this to improve privacy.") \ 654 \ 655 product(bool, PrintWarnings, true, \ 656 "Print JVM warnings to output stream") \ 657 \ 658 product(bool, RegisterFinalizersAtInit, true, \ 659 "Register finalizable objects at end of Object.<init> or " \ 660 "after allocation") \ 661 \ 662 develop(bool, RegisterReferences, true, \ 663 "Tell whether the VM should register soft/weak/final/phantom " \ 664 "references") \ 665 \ 666 develop(bool, PrintCodeCacheExtension, false, \ 667 "Print extension of code cache") \ 668 \ 669 develop(bool, UsePrivilegedStack, true, \ 670 "Enable the security JVM functions") \ 671 \ 672 product(bool, ClassUnloading, true, \ 673 "Do unloading of classes") \ 674 \ 675 product(bool, ClassUnloadingWithConcurrentMark, true, \ 676 "Do unloading of classes with a concurrent marking cycle") \ 677 \ 678 notproduct(bool, PrintSystemDictionaryAtExit, false, \ 679 "Print the system dictionary at exit") \ 680 \ 681 notproduct(bool, PrintClassLoaderDataGraphAtExit, false, \ 682 "Print the class loader data graph at exit") \ 683 \ 684 product(bool, AllowParallelDefineClass, false, \ 685 "Allow parallel defineClass requests for class loaders " \ 686 "registering as parallel capable") \ 687 \ 688 product(bool, EnableWaitForParallelLoad, false, \ 689 "(Deprecated) Enable legacy parallel classloading logic for " \ 690 "class loaders not registered as parallel capable") \ 691 \ 692 product_pd(bool, DontYieldALot, \ 693 "Throw away obvious excess yield calls") \ 694 \ 695 product(bool, DisablePrimordialThreadGuardPages, false, EXPERIMENTAL, \ 696 "Disable the use of stack guard pages if the JVM is loaded " \ 697 "on the primordial process thread") \ 698 \ 699 product(bool, PostVirtualThreadCompatibleLifecycleEvents, true, EXPERIMENTAL, \ 700 "Post virtual thread ThreadStart and ThreadEnd events for " \ 701 "virtual thread unaware agents") \ 702 \ 703 product(bool, DoJVMTIVirtualThreadTransitions, true, EXPERIMENTAL, \ 704 "Do JVMTI virtual thread mount/unmount transitions " \ 705 "(disabling this flag implies no JVMTI events are posted)") \ 706 \ 707 /* notice: the max range value here is max_jint, not max_intx */ \ 708 /* because of overflow issue */ \ 709 product(intx, AsyncDeflationInterval, 250, DIAGNOSTIC, \ 710 "Async deflate idle monitors every so many milliseconds when " \ 711 "MonitorUsedDeflationThreshold is exceeded (0 is off).") \ 712 range(0, max_jint) \ 713 \ 714 product(size_t, AvgMonitorsPerThreadEstimate, 1024, DIAGNOSTIC, \ 715 "Used to estimate a variable ceiling based on number of threads " \ 716 "for use with MonitorUsedDeflationThreshold (0 is off).") \ 717 range(0, max_uintx) \ 718 \ 719 /* notice: the max range value here is max_jint, not max_intx */ \ 720 /* because of overflow issue */ \ 721 product(intx, MonitorDeflationMax, 1000000, DIAGNOSTIC, \ 722 "The maximum number of monitors to deflate, unlink and delete " \ 723 "at one time (minimum is 1024).") \ 724 range(1024, max_jint) \ 725 \ 726 product(intx, MonitorUsedDeflationThreshold, 90, DIAGNOSTIC, \ 727 "Percentage of used monitors before triggering deflation (0 is " \ 728 "off). The check is performed on GuaranteedSafepointInterval " \ 729 "or AsyncDeflationInterval.") \ 730 range(0, 100) \ 731 \ 732 product(uintx, NoAsyncDeflationProgressMax, 3, DIAGNOSTIC, \ 733 "Max number of no progress async deflation attempts to tolerate " \ 734 "before adjusting the in_use_list_ceiling up (0 is off).") \ 735 range(0, max_uintx) \ 736 \ 737 product(intx, hashCode, 5, EXPERIMENTAL, \ 738 "(Unstable) select hashCode generation algorithm") \ 739 \ 740 product(bool, ReduceSignalUsage, false, \ 741 "Reduce the use of OS signals in Java and/or the VM") \ 742 \ 743 develop(bool, LoadLineNumberTables, true, \ 744 "Tell whether the class file parser loads line number tables") \ 745 \ 746 develop(bool, LoadLocalVariableTables, true, \ 747 "Tell whether the class file parser loads local variable tables") \ 748 \ 749 develop(bool, LoadLocalVariableTypeTables, true, \ 750 "Tell whether the class file parser loads local variable type" \ 751 "tables") \ 752 \ 753 product(bool, AllowUserSignalHandlers, false, \ 754 "Application will install primary signal handlers for the JVM " \ 755 "(Unix only)") \ 756 \ 757 product(bool, UseSignalChaining, true, \ 758 "Use signal-chaining to invoke signal handlers installed " \ 759 "by the application (Unix only)") \ 760 \ 761 product(bool, RestoreMXCSROnJNICalls, false, \ 762 "Restore MXCSR when returning from JNI calls") \ 763 \ 764 product(bool, CheckJNICalls, false, \ 765 "Verify all arguments to JNI calls") \ 766 \ 767 product(bool, UseFastJNIAccessors, true, \ 768 "Use optimized versions of Get<Primitive>Field") \ 769 \ 770 product(intx, MaxJNILocalCapacity, 65536, \ 771 "Maximum allowable local JNI handle capacity to " \ 772 "EnsureLocalCapacity() and PushLocalFrame(), " \ 773 "where <= 0 is unlimited, default: 65536") \ 774 range(min_intx, max_intx) \ 775 \ 776 product(bool, EagerXrunInit, false, \ 777 "Eagerly initialize -Xrun libraries; allows startup profiling, " \ 778 "but not all -Xrun libraries may support the state of the VM " \ 779 "at this time") \ 780 \ 781 product(bool, PreserveAllAnnotations, false, \ 782 "Preserve RuntimeInvisibleAnnotations as well " \ 783 "as RuntimeVisibleAnnotations") \ 784 \ 785 develop(uintx, PreallocatedOutOfMemoryErrorCount, 4, \ 786 "Number of OutOfMemoryErrors preallocated with backtrace") \ 787 \ 788 product(bool, UseXMMForArrayCopy, false, \ 789 "Use SSE2 MOVQ instruction for Arraycopy") \ 790 \ 791 notproduct(bool, PrintFieldLayout, false, \ 792 "Print field layout for each class") \ 793 \ 794 notproduct(bool, PrintInlineLayout, false, \ 795 "Print field layout for each inline type") \ 796 \ 797 notproduct(bool, PrintFlatArrayLayout, false, \ 798 "Print array layout for each inline type array") \ 799 \ 800 product(intx, FlatArrayElementMaxSize, -1, \ 801 "Max size for flattening inline array elements, <0 no limit") \ 802 \ 803 product(intx, InlineFieldMaxFlatSize, 128, \ 804 "Max size for flattening inline type fields, <0 no limit") \ 805 \ 806 product(intx, FlatArrayElementMaxOops, 4, \ 807 "Max nof embedded object references in an inline type to flatten, <0 no limit") \ 808 \ 809 product(bool, InlineArrayAtomicAccess, false, \ 810 "Atomic inline array accesses by-default, for all inline arrays") \ 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(intx, 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 /* tracing */ \ 846 \ 847 develop(bool, StressRewriter, false, \ 848 "Stress linktime bytecode rewriting") \ 849 \ 850 product(ccstr, TraceJVMTI, NULL, \ 851 "Trace flags for JVMTI functions and events") \ 852 \ 853 product(bool, StressLdcRewrite, false, DIAGNOSTIC, \ 854 "Force ldc -> ldc_w rewrite during RedefineClasses. " \ 855 "This option can change an EMCP method into an obsolete method " \ 856 "and can affect tests that expect specific methods to be EMCP. " \ 857 "This option should be used with caution.") \ 858 \ 859 product(bool, AllowRedefinitionToAddDeleteMethods, false, \ 860 "(Deprecated) Allow redefinition to add and delete private " \ 861 "static or final methods for compatibility with old releases") \ 862 \ 863 develop(bool, TraceBytecodes, false, \ 864 "Trace bytecode execution") \ 865 \ 866 develop(bool, TraceICs, false, \ 867 "Trace inline cache changes") \ 868 \ 869 notproduct(bool, TraceInvocationCounterOverflow, false, \ 870 "Trace method invocation counter overflow") \ 871 \ 872 develop(bool, TraceInlineCacheClearing, false, \ 873 "Trace clearing of inline caches in nmethods") \ 874 \ 875 develop(bool, TraceDependencies, false, \ 876 "Trace dependencies") \ 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, TraceICBuffer, false, \ 897 "Trace usage of IC buffer") \ 898 \ 899 develop(bool, TraceCompiledIC, false, \ 900 "Trace changes of compiled IC") \ 901 \ 902 develop(bool, FLSVerifyDictionary, false, \ 903 "Do lots of (expensive) FLS dictionary verification") \ 904 \ 905 \ 906 notproduct(bool, CheckMemoryInitialization, false, \ 907 "Check memory initialization") \ 908 \ 909 product(uintx, ProcessDistributionStride, 4, \ 910 "Stride through processors when distributing processes") \ 911 range(0, max_juint) \ 912 \ 913 develop(bool, TraceFinalizerRegistration, false, \ 914 "Trace registration of final references") \ 915 \ 916 product(bool, IgnoreEmptyClassPaths, false, \ 917 "Ignore empty path elements in -classpath") \ 918 \ 919 product(bool, PrintHeapAtSIGBREAK, true, \ 920 "Print heap layout in response to SIGBREAK") \ 921 \ 922 product(bool, PrintClassHistogram, false, MANAGEABLE, \ 923 "Print a histogram of class instances") \ 924 \ 925 product(double, ObjectCountCutOffPercent, 0.5, EXPERIMENTAL, \ 926 "The percentage of the used heap that the instances of a class " \ 927 "must occupy for the class to generate a trace event") \ 928 range(0.0, 100.0) \ 929 \ 930 /* JVMTI heap profiling */ \ 931 \ 932 product(bool, VerifyBeforeIteration, false, DIAGNOSTIC, \ 933 "Verify memory system before JVMTI iteration") \ 934 \ 935 /* compiler */ \ 936 \ 937 /* notice: the max range value here is max_jint, not max_intx */ \ 938 /* because of overflow issue */ \ 939 product(intx, CICompilerCount, CI_COMPILER_COUNT, \ 940 "Number of compiler threads to run") \ 941 range(0, max_jint) \ 942 constraint(CICompilerCountConstraintFunc, AfterErgo) \ 943 \ 944 product(bool, UseDynamicNumberOfCompilerThreads, true, \ 945 "Dynamically choose the number of parallel compiler threads") \ 946 \ 947 product(bool, ReduceNumberOfCompilerThreads, true, DIAGNOSTIC, \ 948 "Reduce the number of parallel compiler threads when they " \ 949 "are not used") \ 950 \ 951 product(bool, TraceCompilerThreads, false, DIAGNOSTIC, \ 952 "Trace creation and removal of compiler threads") \ 953 \ 954 develop(bool, InjectCompilerCreationFailure, false, \ 955 "Inject thread creation failures for " \ 956 "UseDynamicNumberOfCompilerThreads") \ 957 \ 958 develop(bool, GenerateSynchronizationCode, true, \ 959 "generate locking/unlocking code for synchronized methods and " \ 960 "monitors") \ 961 \ 962 develop(bool, GenerateRangeChecks, true, \ 963 "Generate range checks for array accesses") \ 964 \ 965 product_pd(bool, ImplicitNullChecks, DIAGNOSTIC, \ 966 "Generate code for implicit null checks") \ 967 \ 968 product_pd(bool, TrapBasedNullChecks, \ 969 "Generate code for null checks that uses a cmp and trap " \ 970 "instruction raising SIGTRAP. This is only used if an access to" \ 971 "null (+offset) will not raise a SIGSEGV, i.e.," \ 972 "ImplicitNullChecks don't work (PPC64).") \ 973 \ 974 product(bool, EnableThreadSMRExtraValidityChecks, true, DIAGNOSTIC, \ 975 "Enable Thread SMR extra validity checks") \ 976 \ 977 product(bool, EnableThreadSMRStatistics, trueInDebug, DIAGNOSTIC, \ 978 "Enable Thread SMR Statistics") \ 979 \ 980 product(bool, UseNotificationThread, true, \ 981 "Use Notification Thread") \ 982 \ 983 product(bool, Inline, true, \ 984 "Enable inlining") \ 985 \ 986 product(bool, ClipInlining, true, \ 987 "Clip inlining if aggregate method exceeds DesiredMethodLimit") \ 988 \ 989 develop(bool, UseCHA, true, \ 990 "Enable CHA") \ 991 \ 992 product(bool, UseVtableBasedCHA, true, DIAGNOSTIC, \ 993 "Use vtable information during CHA") \ 994 \ 995 product(bool, UseTypeProfile, true, \ 996 "Check interpreter profile for historically monomorphic calls") \ 997 \ 998 product(bool, PrintInlining, false, DIAGNOSTIC, \ 999 "Print inlining optimizations") \ 1000 \ 1001 product(bool, UsePopCountInstruction, false, \ 1002 "Use population count instruction") \ 1003 \ 1004 develop(bool, TraceMethodReplacement, false, \ 1005 "Print when methods are replaced do to recompilation") \ 1006 \ 1007 product(bool, PrintMethodFlushingStatistics, false, DIAGNOSTIC, \ 1008 "print statistics about method flushing") \ 1009 \ 1010 product(intx, MinPassesBeforeFlush, 10, DIAGNOSTIC, \ 1011 "Minimum number of sweeper passes before an nmethod " \ 1012 "can be flushed") \ 1013 range(0, max_intx) \ 1014 \ 1015 develop(bool, StressCodeBuffers, false, \ 1016 "Exercise code buffer expansion and other rare state changes") \ 1017 \ 1018 product(bool, DebugNonSafepoints, trueInDebug, DIAGNOSTIC, \ 1019 "Generate extra debugging information for non-safepoints in " \ 1020 "nmethods") \ 1021 \ 1022 product(bool, PrintVMOptions, false, \ 1023 "Print flags that appeared on the command line") \ 1024 \ 1025 product(bool, IgnoreUnrecognizedVMOptions, false, \ 1026 "Ignore unrecognized VM options") \ 1027 \ 1028 product(bool, PrintCommandLineFlags, false, \ 1029 "Print flags specified on command line or set by ergonomics") \ 1030 \ 1031 product(bool, PrintFlagsInitial, false, \ 1032 "Print all VM flags before argument processing and exit VM") \ 1033 \ 1034 product(bool, PrintFlagsFinal, false, \ 1035 "Print all VM flags after argument and ergonomic processing") \ 1036 \ 1037 notproduct(bool, PrintFlagsWithComments, false, \ 1038 "Print all VM flags with default values and descriptions and " \ 1039 "exit") \ 1040 \ 1041 product(bool, PrintFlagsRanges, false, \ 1042 "Print VM flags and their ranges") \ 1043 \ 1044 product(bool, SerializeVMOutput, true, DIAGNOSTIC, \ 1045 "Use a mutex to serialize output to tty and LogFile") \ 1046 \ 1047 product(bool, DisplayVMOutput, true, DIAGNOSTIC, \ 1048 "Display all VM output on the tty, independently of LogVMOutput") \ 1049 \ 1050 product(bool, LogVMOutput, false, DIAGNOSTIC, \ 1051 "Save VM output to LogFile") \ 1052 \ 1053 product(ccstr, LogFile, NULL, DIAGNOSTIC, \ 1054 "If LogVMOutput or LogCompilation is on, save VM output to " \ 1055 "this file [default: ./hotspot_pid%p.log] (%p replaced with pid)")\ 1056 \ 1057 product(ccstr, ErrorFile, NULL, \ 1058 "If an error occurs, save the error data to this file " \ 1059 "[default: ./hs_err_pid%p.log] (%p replaced with pid)") \ 1060 \ 1061 product(bool, ExtensiveErrorReports, \ 1062 PRODUCT_ONLY(false) NOT_PRODUCT(true), \ 1063 "Error reports are more extensive.") \ 1064 \ 1065 product(bool, DisplayVMOutputToStderr, false, \ 1066 "If DisplayVMOutput is true, display all VM output to stderr") \ 1067 \ 1068 product(bool, DisplayVMOutputToStdout, false, \ 1069 "If DisplayVMOutput is true, display all VM output to stdout") \ 1070 \ 1071 product(bool, ErrorFileToStderr, false, \ 1072 "If true, error data is printed to stderr instead of a file") \ 1073 \ 1074 product(bool, ErrorFileToStdout, false, \ 1075 "If true, error data is printed to stdout instead of a file") \ 1076 \ 1077 develop(bool, UseHeavyMonitors, false, \ 1078 "(Deprecated) Use heavyweight instead of lightweight Java " \ 1079 "monitors") \ 1080 \ 1081 develop(bool, VerifyHeavyMonitors, false, \ 1082 "Checks that no stack locking happens when using " \ 1083 "+UseHeavyMonitors") \ 1084 \ 1085 product(bool, PrintStringTableStatistics, false, \ 1086 "print statistics about the StringTable and SymbolTable") \ 1087 \ 1088 product(bool, VerifyStringTableAtExit, false, DIAGNOSTIC, \ 1089 "verify StringTable contents at exit") \ 1090 \ 1091 notproduct(bool, PrintSymbolTableSizeHistogram, false, \ 1092 "print histogram of the symbol table") \ 1093 \ 1094 product(ccstr, AbortVMOnException, NULL, DIAGNOSTIC, \ 1095 "Call fatal if this exception is thrown. Example: " \ 1096 "java -XX:AbortVMOnException=java.lang.NullPointerException Foo") \ 1097 \ 1098 product(ccstr, AbortVMOnExceptionMessage, NULL, DIAGNOSTIC, \ 1099 "Call fatal if the exception pointed by AbortVMOnException " \ 1100 "has this message") \ 1101 \ 1102 develop(bool, DebugVtables, false, \ 1103 "add debugging code to vtable dispatch") \ 1104 \ 1105 product(bool, RangeCheckElimination, true, \ 1106 "Eliminate range checks") \ 1107 \ 1108 develop_pd(bool, UncommonNullCast, \ 1109 "track occurrences of null in casts; adjust compiler tactics") \ 1110 \ 1111 develop(bool, TypeProfileCasts, true, \ 1112 "treat casts like calls for purposes of type profiling") \ 1113 \ 1114 develop(bool, TraceLivenessGen, false, \ 1115 "Trace the generation of liveness analysis information") \ 1116 \ 1117 notproduct(bool, TraceLivenessQuery, false, \ 1118 "Trace queries of liveness analysis information") \ 1119 \ 1120 notproduct(bool, CollectIndexSetStatistics, false, \ 1121 "Collect information about IndexSets") \ 1122 \ 1123 develop(intx, FastAllocateSizeLimit, 128*K, \ 1124 /* Note: This value is zero mod 1<<13 for a cheap sparc set. */ \ 1125 "Inline allocations larger than this in doublewords must go slow")\ 1126 \ 1127 product_pd(bool, CompactStrings, \ 1128 "Enable Strings to use single byte chars in backing store") \ 1129 \ 1130 product_pd(uintx, TypeProfileLevel, \ 1131 "=XYZ, with Z: Type profiling of arguments at call; " \ 1132 "Y: Type profiling of return value at call; " \ 1133 "X: Type profiling of parameters to methods; " \ 1134 "X, Y and Z in 0=off ; 1=jsr292 only; 2=all methods") \ 1135 constraint(TypeProfileLevelConstraintFunc, AfterErgo) \ 1136 \ 1137 product(intx, TypeProfileArgsLimit, 2, \ 1138 "max number of call arguments to consider for type profiling") \ 1139 range(0, 16) \ 1140 \ 1141 product(intx, TypeProfileParmsLimit, 2, \ 1142 "max number of incoming parameters to consider for type profiling"\ 1143 ", -1 for all") \ 1144 range(-1, 64) \ 1145 \ 1146 /* statistics */ \ 1147 develop(bool, CountCompiledCalls, false, \ 1148 "Count method invocations") \ 1149 \ 1150 notproduct(bool, ICMissHistogram, false, \ 1151 "Produce histogram of IC misses") \ 1152 \ 1153 /* interpreter */ \ 1154 product_pd(bool, RewriteBytecodes, \ 1155 "Allow rewriting of bytecodes (bytecodes are not immutable)") \ 1156 \ 1157 product_pd(bool, RewriteFrequentPairs, \ 1158 "Rewrite frequently used bytecode pairs into a single bytecode") \ 1159 \ 1160 product(bool, PrintInterpreter, false, DIAGNOSTIC, \ 1161 "Print the generated interpreter code") \ 1162 \ 1163 product(bool, UseInterpreter, true, \ 1164 "Use interpreter for non-compiled methods") \ 1165 \ 1166 develop(bool, UseFastSignatureHandlers, true, \ 1167 "Use fast signature handlers for native calls") \ 1168 \ 1169 product(bool, UseLoopCounter, true, \ 1170 "Increment invocation counter on backward branch") \ 1171 \ 1172 product_pd(bool, UseOnStackReplacement, \ 1173 "Use on stack replacement, calls runtime if invoc. counter " \ 1174 "overflows in loop") \ 1175 \ 1176 notproduct(bool, TraceOnStackReplacement, false, \ 1177 "Trace on stack replacement") \ 1178 \ 1179 product_pd(bool, PreferInterpreterNativeStubs, \ 1180 "Use always interpreter stubs for native methods invoked via " \ 1181 "interpreter") \ 1182 \ 1183 develop(bool, CountBytecodes, false, \ 1184 "Count number of bytecodes executed") \ 1185 \ 1186 develop(bool, PrintBytecodeHistogram, false, \ 1187 "Print histogram of the executed bytecodes") \ 1188 \ 1189 develop(bool, PrintBytecodePairHistogram, false, \ 1190 "Print histogram of the executed bytecode pairs") \ 1191 \ 1192 product(bool, PrintSignatureHandlers, false, DIAGNOSTIC, \ 1193 "Print code generated for native method signature handlers") \ 1194 \ 1195 develop(bool, VerifyOops, false, \ 1196 "Do plausibility checks for oops") \ 1197 \ 1198 develop(bool, CheckUnhandledOops, false, \ 1199 "Check for unhandled oops in VM code") \ 1200 \ 1201 develop(bool, VerifyJNIFields, trueInDebug, \ 1202 "Verify jfieldIDs for instance fields") \ 1203 \ 1204 develop(bool, VerifyFPU, false, \ 1205 "Verify FPU state (check for NaN's, etc.)") \ 1206 \ 1207 develop(bool, VerifyThread, false, \ 1208 "Watch the thread register for corruption (SPARC only)") \ 1209 \ 1210 develop(bool, VerifyActivationFrameSize, false, \ 1211 "Verify that activation frame didn't become smaller than its " \ 1212 "minimal size") \ 1213 \ 1214 develop(bool, TraceFrequencyInlining, false, \ 1215 "Trace frequency based inlining") \ 1216 \ 1217 develop_pd(bool, InlineIntrinsics, \ 1218 "Inline intrinsics that can be statically resolved") \ 1219 \ 1220 product_pd(bool, ProfileInterpreter, \ 1221 "Profile at the bytecode level during interpretation") \ 1222 \ 1223 develop_pd(bool, ProfileTraps, \ 1224 "Profile deoptimization traps at the bytecode level") \ 1225 \ 1226 product(intx, ProfileMaturityPercentage, 20, \ 1227 "number of method invocations/branches (expressed as % of " \ 1228 "CompileThreshold) before using the method's profile") \ 1229 range(0, 100) \ 1230 \ 1231 product(bool, PrintMethodData, false, DIAGNOSTIC, \ 1232 "Print the results of +ProfileInterpreter at end of run") \ 1233 \ 1234 develop(bool, VerifyDataPointer, trueInDebug, \ 1235 "Verify the method data pointer during interpreter profiling") \ 1236 \ 1237 notproduct(bool, CrashGCForDumpingJavaThread, false, \ 1238 "Manually make GC thread crash then dump java stack trace; " \ 1239 "Test only") \ 1240 \ 1241 /* compilation */ \ 1242 product(bool, UseCompiler, true, \ 1243 "Use Just-In-Time compilation") \ 1244 \ 1245 product(bool, UseCounterDecay, true, \ 1246 "Adjust recompilation counters") \ 1247 \ 1248 develop(intx, CounterHalfLifeTime, 30, \ 1249 "Half-life time of invocation counters (in seconds)") \ 1250 \ 1251 develop(intx, CounterDecayMinIntervalLength, 500, \ 1252 "The minimum interval (in milliseconds) between invocation of " \ 1253 "CounterDecay") \ 1254 \ 1255 product(bool, AlwaysCompileLoopMethods, false, \ 1256 "When using recompilation, never interpret methods " \ 1257 "containing loops") \ 1258 \ 1259 product(intx, AllocatePrefetchStyle, 1, \ 1260 "0 = no prefetch, " \ 1261 "1 = generate prefetch instructions for each allocation, " \ 1262 "2 = use TLAB watermark to gate allocation prefetch, " \ 1263 "3 = generate one prefetch instruction per cache line") \ 1264 range(0, 3) \ 1265 \ 1266 product(intx, AllocatePrefetchDistance, -1, \ 1267 "Distance to prefetch ahead of allocation pointer. " \ 1268 "-1: use system-specific value (automatically determined") \ 1269 constraint(AllocatePrefetchDistanceConstraintFunc,AfterMemoryInit)\ 1270 \ 1271 product(intx, AllocatePrefetchLines, 3, \ 1272 "Number of lines to prefetch ahead of array allocation pointer") \ 1273 range(1, 64) \ 1274 \ 1275 product(intx, AllocateInstancePrefetchLines, 1, \ 1276 "Number of lines to prefetch ahead of instance allocation " \ 1277 "pointer") \ 1278 range(1, 64) \ 1279 \ 1280 product(intx, AllocatePrefetchStepSize, 16, \ 1281 "Step size in bytes of sequential prefetch instructions") \ 1282 range(1, 512) \ 1283 constraint(AllocatePrefetchStepSizeConstraintFunc,AfterMemoryInit)\ 1284 \ 1285 product(intx, AllocatePrefetchInstr, 0, \ 1286 "Select instruction to prefetch ahead of allocation pointer") \ 1287 constraint(AllocatePrefetchInstrConstraintFunc, AfterMemoryInit) \ 1288 \ 1289 /* deoptimization */ \ 1290 product(bool, TraceDeoptimization, false, DIAGNOSTIC, \ 1291 "Trace deoptimization") \ 1292 \ 1293 develop(bool, PrintDeoptimizationDetails, false, \ 1294 "Print more information about deoptimization") \ 1295 \ 1296 develop(bool, DebugDeoptimization, false, \ 1297 "Tracing various information while debugging deoptimization") \ 1298 \ 1299 product(double, SelfDestructTimer, 0.0, \ 1300 "Will cause VM to terminate after a given time " \ 1301 "(in fractional minutes) " \ 1302 "(0.0 means off)") \ 1303 range(0.0, (double)max_intx) \ 1304 \ 1305 product(intx, MaxJavaStackTraceDepth, 1024, \ 1306 "The maximum number of lines in the stack trace for Java " \ 1307 "exceptions (0 means all)") \ 1308 range(0, max_jint/2) \ 1309 \ 1310 /* notice: the max range value here is max_jint, not max_intx */ \ 1311 /* because of overflow issue */ \ 1312 product(intx, GuaranteedSafepointInterval, 1000, DIAGNOSTIC, \ 1313 "Guarantee a safepoint (at least) every so many milliseconds " \ 1314 "(0 means none)") \ 1315 range(0, max_jint) \ 1316 \ 1317 product(intx, SafepointTimeoutDelay, 10000, \ 1318 "Delay in milliseconds for option SafepointTimeout") \ 1319 range(0, max_intx LP64_ONLY(/MICROUNITS)) \ 1320 \ 1321 product(bool, UseSystemMemoryBarrier, false, EXPERIMENTAL, \ 1322 "Try to enable system memory barrier") \ 1323 \ 1324 product(intx, NmethodSweepActivity, 4, \ 1325 "Removes cold nmethods from code cache if > 0. Higher values " \ 1326 "result in more aggressive sweeping") \ 1327 range(0, 2000) \ 1328 \ 1329 develop(intx, MallocCatchPtr, -1, \ 1330 "Hit breakpoint when mallocing/freeing this pointer") \ 1331 \ 1332 notproduct(ccstrlist, SuppressErrorAt, "", \ 1333 "List of assertions (file:line) to muzzle") \ 1334 \ 1335 develop(intx, StackPrintLimit, 100, \ 1336 "number of stack frames to print in VM-level stack dump") \ 1337 \ 1338 product(int, ErrorLogPrintCodeLimit, 3, DIAGNOSTIC, \ 1339 "max number of compiled code units to print in error log") \ 1340 range(0, VMError::max_error_log_print_code) \ 1341 \ 1342 notproduct(intx, MaxElementPrintSize, 256, \ 1343 "maximum number of elements to print") \ 1344 \ 1345 notproduct(intx, MaxSubklassPrintSize, 4, \ 1346 "maximum number of subklasses to print when printing klass") \ 1347 \ 1348 develop(intx, MaxForceInlineLevel, 100, \ 1349 "maximum number of nested calls that are forced for inlining " \ 1350 "(using CompileCommand or marked w/ @ForceInline)") \ 1351 range(0, max_jint) \ 1352 \ 1353 develop(intx, MethodHistogramCutoff, 100, \ 1354 "The cutoff value for method invocation histogram (+CountCalls)") \ 1355 \ 1356 develop(intx, DontYieldALotInterval, 10, \ 1357 "Interval between which yields will be dropped (milliseconds)") \ 1358 \ 1359 notproduct(intx, DeoptimizeALotInterval, 5, \ 1360 "Number of exits until DeoptimizeALot kicks in") \ 1361 \ 1362 notproduct(intx, ZombieALotInterval, 5, \ 1363 "Number of exits until ZombieALot kicks in") \ 1364 \ 1365 product(uintx, MallocMaxTestWords, 0, DIAGNOSTIC, \ 1366 "If non-zero, maximum number of words that malloc/realloc can " \ 1367 "allocate (for testing only)") \ 1368 range(0, max_uintx) \ 1369 \ 1370 product(ccstr, MallocLimit, nullptr, DIAGNOSTIC, \ 1371 "Limit malloc allocation size from VM. Reaching the limit will " \ 1372 "trigger a fatal error. This feature requires " \ 1373 "NativeMemoryTracking=summary or NativeMemoryTracking=detail." \ 1374 "Usage:" \ 1375 "- MallocLimit=<size> to set a total limit. " \ 1376 "- MallocLimit=<NMT category>:<size>[,<NMT category>:<size>...] " \ 1377 " to set one or more category-specific limits." \ 1378 "Example: -XX:MallocLimit=compiler:500m") \ 1379 \ 1380 product(intx, TypeProfileWidth, 2, \ 1381 "Number of receiver types to record in call/cast profile") \ 1382 range(0, 8) \ 1383 \ 1384 develop(intx, BciProfileWidth, 2, \ 1385 "Number of return bci's to record in ret profile") \ 1386 \ 1387 product(intx, PerMethodRecompilationCutoff, 400, \ 1388 "After recompiling N times, stay in the interpreter (-1=>'Inf')") \ 1389 range(-1, max_intx) \ 1390 \ 1391 product(intx, PerBytecodeRecompilationCutoff, 200, \ 1392 "Per-BCI limit on repeated recompilation (-1=>'Inf')") \ 1393 range(-1, max_intx) \ 1394 \ 1395 product(intx, PerMethodTrapLimit, 100, \ 1396 "Limit on traps (of one kind) in a method (includes inlines)") \ 1397 range(0, max_jint) \ 1398 \ 1399 product(intx, PerMethodSpecTrapLimit, 5000, EXPERIMENTAL, \ 1400 "Limit on speculative traps (of one kind) in a method " \ 1401 "(includes inlines)") \ 1402 range(0, max_jint) \ 1403 \ 1404 product(intx, PerBytecodeTrapLimit, 4, \ 1405 "Limit on traps (of one kind) at a particular BCI") \ 1406 range(0, max_jint) \ 1407 \ 1408 product(intx, SpecTrapLimitExtraEntries, 3, EXPERIMENTAL, \ 1409 "Extra method data trap entries for speculation") \ 1410 \ 1411 product(double, InlineFrequencyRatio, 0.25, DIAGNOSTIC, \ 1412 "Ratio of call site execution to caller method invocation") \ 1413 \ 1414 product(double, MinInlineFrequencyRatio, 0.0085, DIAGNOSTIC, \ 1415 "Minimum ratio of call site execution to caller method" \ 1416 "invocation to be considered for inlining") \ 1417 \ 1418 develop(intx, InlineThrowCount, 50, \ 1419 "Force inlining of interpreted methods that throw this often") \ 1420 range(0, max_jint) \ 1421 \ 1422 develop(intx, InlineThrowMaxSize, 200, \ 1423 "Force inlining of throwing methods smaller than this") \ 1424 range(0, max_jint) \ 1425 \ 1426 product(size_t, MetaspaceSize, NOT_LP64(16 * M) LP64_ONLY(21 * M), \ 1427 "Initial threshold (in bytes) at which a garbage collection " \ 1428 "is done to reduce Metaspace usage") \ 1429 constraint(MetaspaceSizeConstraintFunc,AfterErgo) \ 1430 \ 1431 product(size_t, MaxMetaspaceSize, max_uintx, \ 1432 "Maximum size of Metaspaces (in bytes)") \ 1433 constraint(MaxMetaspaceSizeConstraintFunc,AfterErgo) \ 1434 \ 1435 product(size_t, CompressedClassSpaceSize, 1*G, \ 1436 "Maximum size of class area in Metaspace when compressed " \ 1437 "class pointers are used") \ 1438 range(1*M, 3*G) \ 1439 \ 1440 develop(size_t, CompressedClassSpaceBaseAddress, 0, \ 1441 "Force the class space to be allocated at this address or " \ 1442 "fails VM initialization (requires -Xshare=off.") \ 1443 \ 1444 product(ccstr, MetaspaceReclaimPolicy, "balanced", \ 1445 "options: balanced, aggressive, none") \ 1446 \ 1447 product(bool, PrintMetaspaceStatisticsAtExit, false, DIAGNOSTIC, \ 1448 "Print metaspace statistics upon VM exit.") \ 1449 \ 1450 develop(bool, MetaspaceGuardAllocations, false, \ 1451 "Metapace allocations are guarded.") \ 1452 \ 1453 product(uintx, MinHeapFreeRatio, 40, MANAGEABLE, \ 1454 "The minimum percentage of heap free after GC to avoid expansion."\ 1455 " For most GCs this applies to the old generation. In G1 and" \ 1456 " ParallelGC it applies to the whole heap.") \ 1457 range(0, 100) \ 1458 constraint(MinHeapFreeRatioConstraintFunc,AfterErgo) \ 1459 \ 1460 product(uintx, MaxHeapFreeRatio, 70, MANAGEABLE, \ 1461 "The maximum percentage of heap free after GC to avoid shrinking."\ 1462 " For most GCs this applies to the old generation. In G1 and" \ 1463 " ParallelGC it applies to the whole heap.") \ 1464 range(0, 100) \ 1465 constraint(MaxHeapFreeRatioConstraintFunc,AfterErgo) \ 1466 \ 1467 product(bool, ShrinkHeapInSteps, true, \ 1468 "When disabled, informs the GC to shrink the java heap directly" \ 1469 " to the target size at the next full GC rather than requiring" \ 1470 " smaller steps during multiple full GCs.") \ 1471 \ 1472 product(intx, SoftRefLRUPolicyMSPerMB, 1000, \ 1473 "Number of milliseconds per MB of free space in the heap") \ 1474 range(0, max_intx) \ 1475 constraint(SoftRefLRUPolicyMSPerMBConstraintFunc,AfterMemoryInit) \ 1476 \ 1477 product(size_t, MinHeapDeltaBytes, ScaleForWordSize(128*K), \ 1478 "The minimum change in heap space due to GC (in bytes)") \ 1479 range(0, max_uintx) \ 1480 \ 1481 product(size_t, MinMetaspaceExpansion, ScaleForWordSize(256*K), \ 1482 "The minimum expansion of Metaspace (in bytes)") \ 1483 range(0, max_uintx) \ 1484 \ 1485 product(uintx, MaxMetaspaceFreeRatio, 70, \ 1486 "The maximum percentage of Metaspace free after GC to avoid " \ 1487 "shrinking") \ 1488 range(0, 100) \ 1489 constraint(MaxMetaspaceFreeRatioConstraintFunc,AfterErgo) \ 1490 \ 1491 product(uintx, MinMetaspaceFreeRatio, 40, \ 1492 "The minimum percentage of Metaspace free after GC to avoid " \ 1493 "expansion") \ 1494 range(0, 99) \ 1495 constraint(MinMetaspaceFreeRatioConstraintFunc,AfterErgo) \ 1496 \ 1497 product(size_t, MaxMetaspaceExpansion, ScaleForWordSize(4*M), \ 1498 "The maximum expansion of Metaspace without full GC (in bytes)") \ 1499 range(0, max_uintx) \ 1500 \ 1501 /* stack parameters */ \ 1502 product_pd(intx, StackYellowPages, \ 1503 "Number of yellow zone (recoverable overflows) pages of size " \ 1504 "4KB. If pages are bigger yellow zone is aligned up.") \ 1505 range(MIN_STACK_YELLOW_PAGES, (DEFAULT_STACK_YELLOW_PAGES+5)) \ 1506 \ 1507 product_pd(intx, StackRedPages, \ 1508 "Number of red zone (unrecoverable overflows) pages of size " \ 1509 "4KB. If pages are bigger red zone is aligned up.") \ 1510 range(MIN_STACK_RED_PAGES, (DEFAULT_STACK_RED_PAGES+2)) \ 1511 \ 1512 product_pd(intx, StackReservedPages, \ 1513 "Number of reserved zone (reserved to annotated methods) pages" \ 1514 " of size 4KB. If pages are bigger reserved zone is aligned up.") \ 1515 range(MIN_STACK_RESERVED_PAGES, (DEFAULT_STACK_RESERVED_PAGES+10))\ 1516 \ 1517 product(bool, RestrictReservedStack, true, \ 1518 "Restrict @ReservedStackAccess to trusted classes") \ 1519 \ 1520 /* greater stack shadow pages can't generate instruction to bang stack */ \ 1521 product_pd(intx, StackShadowPages, \ 1522 "Number of shadow zone (for overflow checking) pages of size " \ 1523 "4KB. If pages are bigger shadow zone is aligned up. " \ 1524 "This should exceed the depth of the VM and native call stack.") \ 1525 range(MIN_STACK_SHADOW_PAGES, (DEFAULT_STACK_SHADOW_PAGES+30)) \ 1526 \ 1527 product_pd(intx, ThreadStackSize, \ 1528 "Thread Stack Size (in Kbytes)") \ 1529 range(0, 1 * M) \ 1530 \ 1531 product_pd(intx, VMThreadStackSize, \ 1532 "Non-Java Thread Stack Size (in Kbytes)") \ 1533 range(0, max_intx/(1 * K)) \ 1534 \ 1535 product_pd(intx, CompilerThreadStackSize, \ 1536 "Compiler Thread Stack Size (in Kbytes)") \ 1537 range(0, max_intx/(1 * K)) \ 1538 \ 1539 develop_pd(size_t, JVMInvokeMethodSlack, \ 1540 "Stack space (bytes) required for JVM_InvokeMethod to complete") \ 1541 \ 1542 /* code cache parameters */ \ 1543 product_pd(uintx, CodeCacheSegmentSize, EXPERIMENTAL, \ 1544 "Code cache segment size (in bytes) - smallest unit of " \ 1545 "allocation") \ 1546 range(1, 1024) \ 1547 constraint(CodeCacheSegmentSizeConstraintFunc, AfterErgo) \ 1548 \ 1549 product_pd(intx, CodeEntryAlignment, EXPERIMENTAL, \ 1550 "Code entry alignment for generated code (in bytes)") \ 1551 constraint(CodeEntryAlignmentConstraintFunc, AfterErgo) \ 1552 \ 1553 product_pd(intx, OptoLoopAlignment, \ 1554 "Align inner loops to zero relative to this modulus") \ 1555 range(1, 128) \ 1556 constraint(OptoLoopAlignmentConstraintFunc, AfterErgo) \ 1557 \ 1558 product_pd(uintx, InitialCodeCacheSize, \ 1559 "Initial code cache size (in bytes)") \ 1560 constraint(VMPageSizeConstraintFunc, AtParse) \ 1561 \ 1562 develop_pd(uintx, CodeCacheMinimumUseSpace, \ 1563 "Minimum code cache size (in bytes) required to start VM.") \ 1564 range(0, max_uintx) \ 1565 \ 1566 product(bool, SegmentedCodeCache, false, \ 1567 "Use a segmented code cache") \ 1568 \ 1569 product_pd(uintx, ReservedCodeCacheSize, \ 1570 "Reserved code cache size (in bytes) - maximum code cache size") \ 1571 constraint(VMPageSizeConstraintFunc, AtParse) \ 1572 \ 1573 product_pd(uintx, NonProfiledCodeHeapSize, \ 1574 "Size of code heap with non-profiled methods (in bytes)") \ 1575 range(0, max_uintx) \ 1576 \ 1577 product_pd(uintx, ProfiledCodeHeapSize, \ 1578 "Size of code heap with profiled methods (in bytes)") \ 1579 range(0, max_uintx) \ 1580 \ 1581 product_pd(uintx, NonNMethodCodeHeapSize, \ 1582 "Size of code heap with non-nmethods (in bytes)") \ 1583 constraint(VMPageSizeConstraintFunc, AtParse) \ 1584 \ 1585 product_pd(uintx, CodeCacheExpansionSize, \ 1586 "Code cache expansion size (in bytes)") \ 1587 range(32*K, max_uintx) \ 1588 \ 1589 product_pd(uintx, CodeCacheMinBlockLength, DIAGNOSTIC, \ 1590 "Minimum number of segments in a code cache block") \ 1591 range(1, 100) \ 1592 \ 1593 notproduct(bool, ExitOnFullCodeCache, false, \ 1594 "Exit the VM if we fill the code cache") \ 1595 \ 1596 product(bool, UseCodeCacheFlushing, true, \ 1597 "Remove cold/old nmethods from the code cache") \ 1598 \ 1599 product(double, SweeperThreshold, 15.0, \ 1600 "Threshold when a code cache unloading GC is invoked." \ 1601 "Value is percentage of ReservedCodeCacheSize.") \ 1602 range(0.0, 100.0) \ 1603 \ 1604 product(uintx, StartAggressiveSweepingAt, 10, \ 1605 "Start aggressive sweeping if X[%] of the code cache is free." \ 1606 "Segmented code cache: X[%] of the non-profiled heap." \ 1607 "Non-segmented code cache: X[%] of the total code cache") \ 1608 range(0, 100) \ 1609 \ 1610 /* interpreter debugging */ \ 1611 develop(intx, BinarySwitchThreshold, 5, \ 1612 "Minimal number of lookupswitch entries for rewriting to binary " \ 1613 "switch") \ 1614 \ 1615 develop(intx, StopInterpreterAt, 0, \ 1616 "Stop interpreter execution at specified bytecode number") \ 1617 \ 1618 develop(intx, TraceBytecodesAt, 0, \ 1619 "Trace bytecodes starting with specified bytecode number") \ 1620 \ 1621 /* Priorities */ \ 1622 product_pd(bool, UseThreadPriorities, "Use native thread priorities") \ 1623 \ 1624 product(int, ThreadPriorityPolicy, 0, \ 1625 "0 : Normal. "\ 1626 " VM chooses priorities that are appropriate for normal "\ 1627 " applications. "\ 1628 " On Windows applications are allowed to use higher native "\ 1629 " priorities. However, with ThreadPriorityPolicy=0, VM will "\ 1630 " not use the highest possible native priority, "\ 1631 " THREAD_PRIORITY_TIME_CRITICAL, as it may interfere with "\ 1632 " system threads. On Linux thread priorities are ignored "\ 1633 " because the OS does not support static priority in "\ 1634 " SCHED_OTHER scheduling class which is the only choice for "\ 1635 " non-root, non-realtime applications. "\ 1636 "1 : Aggressive. "\ 1637 " Java thread priorities map over to the entire range of "\ 1638 " native thread priorities. Higher Java thread priorities map "\ 1639 " to higher native thread priorities. This policy should be "\ 1640 " used with care, as sometimes it can cause performance "\ 1641 " degradation in the application and/or the entire system. On "\ 1642 " Linux/BSD/macOS this policy requires root privilege or an "\ 1643 " extended capability.") \ 1644 range(0, 1) \ 1645 \ 1646 product(bool, ThreadPriorityVerbose, false, \ 1647 "Print priority changes") \ 1648 \ 1649 product(int, CompilerThreadPriority, -1, \ 1650 "The native priority at which compiler threads should run " \ 1651 "(-1 means no change)") \ 1652 range(min_jint, max_jint) \ 1653 \ 1654 product(int, VMThreadPriority, -1, \ 1655 "The native priority at which the VM thread should run " \ 1656 "(-1 means no change)") \ 1657 range(-1, 127) \ 1658 \ 1659 product(int, JavaPriority1_To_OSPriority, -1, \ 1660 "Map Java priorities to OS priorities") \ 1661 range(-1, 127) \ 1662 \ 1663 product(int, JavaPriority2_To_OSPriority, -1, \ 1664 "Map Java priorities to OS priorities") \ 1665 range(-1, 127) \ 1666 \ 1667 product(int, JavaPriority3_To_OSPriority, -1, \ 1668 "Map Java priorities to OS priorities") \ 1669 range(-1, 127) \ 1670 \ 1671 product(int, JavaPriority4_To_OSPriority, -1, \ 1672 "Map Java priorities to OS priorities") \ 1673 range(-1, 127) \ 1674 \ 1675 product(int, JavaPriority5_To_OSPriority, -1, \ 1676 "Map Java priorities to OS priorities") \ 1677 range(-1, 127) \ 1678 \ 1679 product(int, JavaPriority6_To_OSPriority, -1, \ 1680 "Map Java priorities to OS priorities") \ 1681 range(-1, 127) \ 1682 \ 1683 product(int, JavaPriority7_To_OSPriority, -1, \ 1684 "Map Java priorities to OS priorities") \ 1685 range(-1, 127) \ 1686 \ 1687 product(int, JavaPriority8_To_OSPriority, -1, \ 1688 "Map Java priorities to OS priorities") \ 1689 range(-1, 127) \ 1690 \ 1691 product(int, JavaPriority9_To_OSPriority, -1, \ 1692 "Map Java priorities to OS priorities") \ 1693 range(-1, 127) \ 1694 \ 1695 product(int, JavaPriority10_To_OSPriority,-1, \ 1696 "Map Java priorities to OS priorities") \ 1697 range(-1, 127) \ 1698 \ 1699 product(bool, UseCriticalJavaThreadPriority, false, EXPERIMENTAL, \ 1700 "Java thread priority 10 maps to critical scheduling priority") \ 1701 \ 1702 product(bool, UseCriticalCompilerThreadPriority, false, EXPERIMENTAL, \ 1703 "Compiler thread(s) run at critical scheduling priority") \ 1704 \ 1705 develop(intx, NewCodeParameter, 0, \ 1706 "Testing Only: Create a dedicated integer parameter before " \ 1707 "putback") \ 1708 \ 1709 /* new oopmap storage allocation */ \ 1710 develop(intx, MinOopMapAllocation, 8, \ 1711 "Minimum number of OopMap entries in an OopMapSet") \ 1712 \ 1713 /* recompilation */ \ 1714 product_pd(intx, CompileThreshold, \ 1715 "number of interpreted method invocations before (re-)compiling") \ 1716 constraint(CompileThresholdConstraintFunc, AfterErgo) \ 1717 \ 1718 product_pd(bool, TieredCompilation, \ 1719 "Enable tiered compilation") \ 1720 \ 1721 /* Properties for Java libraries */ \ 1722 \ 1723 product(uint64_t, MaxDirectMemorySize, 0, \ 1724 "Maximum total size of NIO direct-buffer allocations. " \ 1725 "Ignored if not explicitly set.") \ 1726 range(0, max_jlong) \ 1727 \ 1728 /* Flags used for temporary code during development */ \ 1729 \ 1730 product(bool, UseNewCode, false, DIAGNOSTIC, \ 1731 "Testing Only: Use the new version while testing") \ 1732 \ 1733 product(bool, UseNewCode2, false, DIAGNOSTIC, \ 1734 "Testing Only: Use the new version while testing") \ 1735 \ 1736 product(bool, UseNewCode3, false, DIAGNOSTIC, \ 1737 "Testing Only: Use the new version while testing") \ 1738 \ 1739 notproduct(bool, UseDebuggerErgo, false, \ 1740 "Debugging Only: Adjust the VM to be more debugger-friendly. " \ 1741 "Turns on the other UseDebuggerErgo* flags") \ 1742 \ 1743 notproduct(bool, UseDebuggerErgo1, false, \ 1744 "Debugging Only: Enable workarounds for debugger induced " \ 1745 "os::processor_id() >= os::processor_count() problems") \ 1746 \ 1747 notproduct(bool, UseDebuggerErgo2, false, \ 1748 "Debugging Only: Limit the number of spawned JVM threads") \ 1749 \ 1750 notproduct(bool, EnableJVMTIStackDepthAsserts, true, \ 1751 "Enable JVMTI asserts related to stack depth checks") \ 1752 \ 1753 /* flags for performance data collection */ \ 1754 \ 1755 product(bool, UsePerfData, true, \ 1756 "Flag to disable jvmstat instrumentation for performance testing "\ 1757 "and problem isolation purposes") \ 1758 \ 1759 product(bool, PerfDataSaveToFile, false, \ 1760 "Save PerfData memory to hsperfdata_<pid> file on exit") \ 1761 \ 1762 product(ccstr, PerfDataSaveFile, NULL, \ 1763 "Save PerfData memory to the specified absolute pathname. " \ 1764 "The string %p in the file name (if present) " \ 1765 "will be replaced by pid") \ 1766 \ 1767 product(intx, PerfDataSamplingInterval, 50, \ 1768 "Data sampling interval (in milliseconds)") \ 1769 range(PeriodicTask::min_interval, max_jint) \ 1770 constraint(PerfDataSamplingIntervalFunc, AfterErgo) \ 1771 \ 1772 product(bool, PerfDisableSharedMem, false, \ 1773 "Store performance data in standard memory") \ 1774 \ 1775 product(int, PerfDataMemorySize, 32*K, \ 1776 "Size of performance data memory region. Will be rounded " \ 1777 "up to a multiple of the native os page size.") \ 1778 range(128, 32*64*K) \ 1779 \ 1780 product(int, PerfMaxStringConstLength, 1024, \ 1781 "Maximum PerfStringConstant string length before truncation") \ 1782 range(32, 32*K) \ 1783 \ 1784 product(bool, PerfAllowAtExitRegistration, false, \ 1785 "Allow registration of atexit() methods") \ 1786 \ 1787 product(bool, PerfBypassFileSystemCheck, false, \ 1788 "Bypass Win32 file system criteria checks (Windows Only)") \ 1789 \ 1790 product(int, UnguardOnExecutionViolation, 0, \ 1791 "Unguard page and retry on no-execute fault (Win32 only) " \ 1792 "0=off, 1=conservative, 2=aggressive") \ 1793 range(0, 2) \ 1794 \ 1795 /* Serviceability Support */ \ 1796 \ 1797 product(bool, ManagementServer, false, \ 1798 "Create JMX Management Server") \ 1799 \ 1800 product(bool, DisableAttachMechanism, false, \ 1801 "Disable mechanism that allows tools to attach to this VM") \ 1802 \ 1803 product(bool, StartAttachListener, false, \ 1804 "Always start Attach Listener at VM startup") \ 1805 \ 1806 product(bool, EnableDynamicAgentLoading, true, \ 1807 "Allow tools to load agents with the attach mechanism") \ 1808 \ 1809 product(bool, PrintConcurrentLocks, false, MANAGEABLE, \ 1810 "Print java.util.concurrent locks in thread dump") \ 1811 \ 1812 product(bool, PrintMethodHandleStubs, false, DIAGNOSTIC, \ 1813 "Print generated stub code for method handles") \ 1814 \ 1815 product(bool, VerifyMethodHandles, trueInDebug, DIAGNOSTIC, \ 1816 "perform extra checks when constructing method handles") \ 1817 \ 1818 product(bool, ShowHiddenFrames, false, DIAGNOSTIC, \ 1819 "show method handle implementation frames (usually hidden)") \ 1820 \ 1821 product(bool, ShowCarrierFrames, false, DIAGNOSTIC, \ 1822 "show virtual threads' carrier frames in exceptions") \ 1823 \ 1824 product(bool, TrustFinalNonStaticFields, false, EXPERIMENTAL, \ 1825 "trust final non-static declarations for constant folding") \ 1826 \ 1827 product(bool, FoldStableValues, true, DIAGNOSTIC, \ 1828 "Optimize loads from stable fields (marked w/ @Stable)") \ 1829 \ 1830 product(int, UseBootstrapCallInfo, 1, DIAGNOSTIC, \ 1831 "0: when resolving InDy or ConDy, force all BSM arguments to be " \ 1832 "resolved before the bootstrap method is called; 1: when a BSM " \ 1833 "that may accept a BootstrapCallInfo is detected, use that API " \ 1834 "to pass BSM arguments, which allows the BSM to delay their " \ 1835 "resolution; 2+: stress test the BCI API by calling more BSMs " \ 1836 "via that API, instead of with the eagerly-resolved array.") \ 1837 \ 1838 product(bool, PauseAtStartup, false, DIAGNOSTIC, \ 1839 "Causes the VM to pause at startup time and wait for the pause " \ 1840 "file to be removed (default: ./vm.paused.<pid>)") \ 1841 \ 1842 product(ccstr, PauseAtStartupFile, NULL, DIAGNOSTIC, \ 1843 "The file to create and for whose removal to await when pausing " \ 1844 "at startup. (default: ./vm.paused.<pid>)") \ 1845 \ 1846 product(bool, PauseAtExit, false, DIAGNOSTIC, \ 1847 "Pause and wait for keypress on exit if a debugger is attached") \ 1848 \ 1849 product(bool, DTraceMethodProbes, false, \ 1850 "Enable dtrace tool probes for method-entry and method-exit") \ 1851 \ 1852 product(bool, DTraceAllocProbes, false, \ 1853 "Enable dtrace tool probes for object allocation") \ 1854 \ 1855 product(bool, DTraceMonitorProbes, false, \ 1856 "Enable dtrace tool probes for monitor events") \ 1857 \ 1858 product(bool, RelaxAccessControlCheck, false, \ 1859 "Relax the access control checks in the verifier") \ 1860 \ 1861 product(uintx, StringTableSize, defaultStringTableSize, \ 1862 "Number of buckets in the interned String table " \ 1863 "(will be rounded to nearest higher power of 2)") \ 1864 range(minimumStringTableSize, 16777216ul /* 2^24 */) \ 1865 \ 1866 product(uintx, SymbolTableSize, defaultSymbolTableSize, EXPERIMENTAL, \ 1867 "Number of buckets in the JVM internal Symbol table") \ 1868 range(minimumSymbolTableSize, 16777216ul /* 2^24 */) \ 1869 \ 1870 product(bool, UseStringDeduplication, false, \ 1871 "Use string deduplication") \ 1872 \ 1873 product(uint, StringDeduplicationAgeThreshold, 3, \ 1874 "A string must reach this age (or be promoted to an old region) " \ 1875 "to be considered for deduplication") \ 1876 range(1, markWord::max_age) \ 1877 \ 1878 product(size_t, StringDeduplicationInitialTableSize, 500, EXPERIMENTAL, \ 1879 "Approximate initial number of buckets in the table") \ 1880 range(1, 1 * G) \ 1881 \ 1882 product(double, StringDeduplicationGrowTableLoad, 14.0, EXPERIMENTAL, \ 1883 "Entries per bucket above which the table should be expanded") \ 1884 range(0.1, 1000.0) \ 1885 \ 1886 product(double, StringDeduplicationShrinkTableLoad, 1.0, EXPERIMENTAL, \ 1887 "Entries per bucket below which the table should be shrunk") \ 1888 range(0.01, 100.0) \ 1889 \ 1890 product(double, StringDeduplicationTargetTableLoad, 7.0, EXPERIMENTAL, \ 1891 "Desired entries per bucket when resizing the table") \ 1892 range(0.01, 1000.0) \ 1893 \ 1894 product(size_t, StringDeduplicationCleanupDeadMinimum, 100, EXPERIMENTAL, \ 1895 "Minimum number of dead table entries for cleaning the table") \ 1896 \ 1897 product(int, StringDeduplicationCleanupDeadPercent, 5, EXPERIMENTAL, \ 1898 "Minimum percentage of dead table entries for cleaning the table") \ 1899 range(1, 100) \ 1900 \ 1901 product(bool, StringDeduplicationResizeALot, false, DIAGNOSTIC, \ 1902 "Force more frequent table resizing") \ 1903 \ 1904 product(uint64_t, StringDeduplicationHashSeed, 0, DIAGNOSTIC, \ 1905 "Seed for the table hashing function; 0 requests computed seed") \ 1906 \ 1907 product(bool, WhiteBoxAPI, false, DIAGNOSTIC, \ 1908 "Enable internal testing APIs") \ 1909 \ 1910 product(size_t, ArrayAllocatorMallocLimit, (size_t)-1, EXPERIMENTAL, \ 1911 "Allocation less than this value will be allocated " \ 1912 "using malloc. Larger allocations will use mmap.") \ 1913 \ 1914 product(bool, AlwaysAtomicAccesses, false, EXPERIMENTAL, \ 1915 "Accesses to all variables should always be atomic") \ 1916 \ 1917 product(bool, UseUnalignedAccesses, false, DIAGNOSTIC, \ 1918 "Use unaligned memory accesses in Unsafe") \ 1919 \ 1920 product_pd(bool, PreserveFramePointer, \ 1921 "Use the FP register for holding the frame pointer " \ 1922 "and not as a general purpose register.") \ 1923 \ 1924 product(size_t, AsyncLogBufferSize, 2*M, \ 1925 "Memory budget (in bytes) for the buffer of Asynchronous " \ 1926 "Logging (-Xlog:async).") \ 1927 range(100*K, 50*M) \ 1928 \ 1929 product(bool, CheckIntrinsics, true, DIAGNOSTIC, \ 1930 "When a class C is loaded, check that " \ 1931 "(1) all intrinsics defined by the VM for class C are present "\ 1932 "in the loaded class file and are marked with the " \ 1933 "@IntrinsicCandidate annotation, that " \ 1934 "(2) there is an intrinsic registered for all loaded methods " \ 1935 "that are annotated with the @IntrinsicCandidate annotation, " \ 1936 "and that " \ 1937 "(3) no orphan methods exist for class C (i.e., methods for " \ 1938 "which the VM declares an intrinsic but that are not declared "\ 1939 "in the loaded class C. " \ 1940 "Check (3) is available only in debug builds.") \ 1941 \ 1942 product_pd(intx, InitArrayShortSize, DIAGNOSTIC, \ 1943 "Threshold small size (in bytes) for clearing arrays. " \ 1944 "Anything this size or smaller may get converted to discrete " \ 1945 "scalar stores.") \ 1946 range(0, max_intx) \ 1947 constraint(InitArrayShortSizeConstraintFunc, AfterErgo) \ 1948 \ 1949 product(ccstr, AllocateHeapAt, NULL, \ 1950 "Path to the directory where a temporary file will be created " \ 1951 "to use as the backing store for Java Heap.") \ 1952 \ 1953 product_pd(bool, VMContinuations, EXPERIMENTAL, \ 1954 "Enable VM continuations support") \ 1955 \ 1956 develop(bool, LoomDeoptAfterThaw, false, \ 1957 "Deopt stack after thaw") \ 1958 \ 1959 develop(bool, LoomVerifyAfterThaw, false, \ 1960 "Verify stack after thaw") \ 1961 \ 1962 develop(bool, VerifyContinuations, false, \ 1963 "Verify continuation consistency") \ 1964 \ 1965 develop(bool, UseContinuationFastPath, true, \ 1966 "Use fast-path frame walking in continuations") \ 1967 \ 1968 develop(int, VerifyMetaspaceInterval, DEBUG_ONLY(500) NOT_DEBUG(0), \ 1969 "Run periodic metaspace verifications (0 - none, " \ 1970 "1 - always, >1 every nth interval)") \ 1971 \ 1972 product(bool, ShowRegistersOnAssert, true, DIAGNOSTIC, \ 1973 "On internal errors, include registers in error report.") \ 1974 \ 1975 product(bool, UseSwitchProfiling, true, DIAGNOSTIC, \ 1976 "leverage profiling for table/lookup switch") \ 1977 \ 1978 develop(bool, TraceMemoryWriteback, false, \ 1979 "Trace memory writeback operations") \ 1980 \ 1981 JFR_ONLY(product(bool, FlightRecorder, false, \ 1982 "(Deprecated) Enable Flight Recorder")) \ 1983 \ 1984 JFR_ONLY(product(ccstr, FlightRecorderOptions, NULL, \ 1985 "Flight Recorder options")) \ 1986 \ 1987 JFR_ONLY(product(ccstr, StartFlightRecording, NULL, \ 1988 "Start flight recording with options")) \ 1989 \ 1990 product(bool, UseFastUnorderedTimeStamps, false, EXPERIMENTAL, \ 1991 "Use platform unstable time where supported for timestamps only") \ 1992 \ 1993 product(bool, EnableValhalla, true, \ 1994 "Enable experimental Valhalla features") \ 1995 \ 1996 product(bool, EnablePrimitiveClasses, false, \ 1997 "Enable experimental Valhalla primitive classes") \ 1998 \ 1999 product_pd(bool, InlineTypePassFieldsAsArgs, \ 2000 "Pass each inline type field as an argument at calls") \ 2001 \ 2002 product_pd(bool, InlineTypeReturnedAsFields, \ 2003 "Return fields instead of an inline type reference") \ 2004 \ 2005 develop(bool, StressInlineTypeReturnedAsFields, false, \ 2006 "Stress return of fields instead of an inline type reference") \ 2007 \ 2008 product(bool, UseArrayMarkWordCheck, NOT_LP64(false) LP64_ONLY(true), \ 2009 "Use bits in the mark word to check for flat/null-free arrays") \ 2010 \ 2011 product(ccstrlist, ForceNonTearable, "", DIAGNOSTIC, \ 2012 "List of inline classes which are forced to be atomic " \ 2013 "(whitespace and commas separate names, " \ 2014 "and leading and trailing stars '*' are wildcards)") \ 2015 \ 2016 product(bool, UseEmptySlotsInSupers, true, \ 2017 "Allow allocating fields in empty slots of super-classes") \ 2018 \ 2019 product(bool, DeoptimizeNMethodBarriersALot, false, DIAGNOSTIC, \ 2020 "Make nmethod barriers deoptimise a lot.") \ 2021 \ 2022 develop(bool, VerifyCrossModifyFence, \ 2023 false AARCH64_ONLY(DEBUG_ONLY(||true)), \ 2024 "Mark all threads after a safepoint, and clear on a modify " \ 2025 "fence. Add cleanliness checks.") \ 2026 2027 // end of RUNTIME_FLAGS 2028 2029 DECLARE_FLAGS(LP64_RUNTIME_FLAGS) 2030 DECLARE_ARCH_FLAGS(ARCH_FLAGS) 2031 DECLARE_FLAGS(RUNTIME_FLAGS) 2032 DECLARE_FLAGS(RUNTIME_OS_FLAGS) 2033 2034 #endif // SHARE_RUNTIME_GLOBALS_HPP