1 /* 2 * Copyright (c) 1997, 2018, 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_GC_SHARED_GC_GLOBALS_HPP 26 #define SHARE_GC_SHARED_GC_GLOBALS_HPP 27 28 #include "utilities/macros.hpp" 29 #if INCLUDE_CMSGC 30 #include "gc/cms/cms_globals.hpp" 31 #endif 32 #if INCLUDE_G1GC 33 #include "gc/g1/g1_globals.hpp" 34 #endif 35 #if INCLUDE_PARALLELGC 36 #include "gc/parallel/parallel_globals.hpp" 37 #endif 38 #if INCLUDE_SERIALGC 39 #include "gc/serial/serial_globals.hpp" 40 #endif 41 42 #define GC_FLAGS(develop, \ 43 develop_pd, \ 44 product, \ 45 product_pd, \ 46 diagnostic, \ 47 diagnostic_pd, \ 48 experimental, \ 49 notproduct, \ 50 manageable, \ 51 product_rw, \ 52 lp64_product, \ 53 range, \ 54 constraint, \ 55 writeable) \ 56 \ 57 CMSGC_ONLY(GC_CMS_FLAGS( \ 58 develop, \ 59 develop_pd, \ 60 product, \ 61 product_pd, \ 62 diagnostic, \ 63 diagnostic_pd, \ 64 experimental, \ 65 notproduct, \ 66 manageable, \ 67 product_rw, \ 68 lp64_product, \ 69 range, \ 70 constraint, \ 71 writeable)) \ 72 \ 73 G1GC_ONLY(GC_G1_FLAGS( \ 74 develop, \ 75 develop_pd, \ 76 product, \ 77 product_pd, \ 78 diagnostic, \ 79 diagnostic_pd, \ 80 experimental, \ 81 notproduct, \ 82 manageable, \ 83 product_rw, \ 84 lp64_product, \ 85 range, \ 86 constraint, \ 87 writeable)) \ 88 \ 89 PARALLELGC_ONLY(GC_PARALLEL_FLAGS( \ 90 develop, \ 91 develop_pd, \ 92 product, \ 93 product_pd, \ 94 diagnostic, \ 95 diagnostic_pd, \ 96 experimental, \ 97 notproduct, \ 98 manageable, \ 99 product_rw, \ 100 lp64_product, \ 101 range, \ 102 constraint, \ 103 writeable)) \ 104 \ 105 SERIALGC_ONLY(GC_SERIAL_FLAGS( \ 106 develop, \ 107 develop_pd, \ 108 product, \ 109 product_pd, \ 110 diagnostic, \ 111 diagnostic_pd, \ 112 experimental, \ 113 notproduct, \ 114 manageable, \ 115 product_rw, \ 116 lp64_product, \ 117 range, \ 118 constraint, \ 119 writeable)) \ 120 \ 121 /* gc */ \ 122 \ 123 product(bool, UseConcMarkSweepGC, false, \ 124 "Use Concurrent Mark-Sweep GC in the old generation") \ 125 \ 126 product(bool, UseSerialGC, false, \ 127 "Use the Serial garbage collector") \ 128 \ 129 product(bool, UseG1GC, false, \ 130 "Use the Garbage-First garbage collector") \ 131 \ 132 product(bool, UseParallelGC, false, \ 133 "Use the Parallel Scavenge garbage collector") \ 134 \ 135 product(bool, UseParallelOldGC, false, \ 136 "Use the Parallel Old garbage collector") \ 137 \ 138 product(uint, ParallelGCThreads, 0, \ 139 "Number of parallel threads parallel gc will use") \ 140 constraint(ParallelGCThreadsConstraintFunc,AfterErgo) \ 141 \ 142 diagnostic(bool, UseSemaphoreGCThreadsSynchronization, true, \ 143 "Use semaphore synchronization for the GC Threads, " \ 144 "instead of synchronization based on mutexes") \ 145 \ 146 product(bool, UseDynamicNumberOfGCThreads, true, \ 147 "Dynamically choose the number of threads up to a maximum of " \ 148 "ParallelGCThreads parallel collectors will use for garbage " \ 149 "collection work") \ 150 \ 151 diagnostic(bool, InjectGCWorkerCreationFailure, false, \ 152 "Inject thread creation failures for " \ 153 "UseDynamicNumberOfGCThreads") \ 154 \ 155 diagnostic(bool, ForceDynamicNumberOfGCThreads, false, \ 156 "Force dynamic selection of the number of " \ 157 "parallel threads parallel gc will use to aid debugging") \ 158 \ 159 product(size_t, HeapSizePerGCThread, ScaleForWordSize(32*M), \ 160 "Size of heap (bytes) per GC thread used in calculating the " \ 161 "number of GC threads") \ 162 range((size_t)os::vm_page_size(), (size_t)max_uintx) \ 163 \ 164 product(uint, ConcGCThreads, 0, \ 165 "Number of threads concurrent gc will use") \ 166 constraint(ConcGCThreadsConstraintFunc,AfterErgo) \ 167 \ 168 product(uint, GCTaskTimeStampEntries, 200, \ 169 "Number of time stamp entries per gc worker thread") \ 170 range(1, max_jint) \ 171 \ 172 product(bool, AlwaysTenure, false, \ 173 "Always tenure objects in eden (ParallelGC only)") \ 174 \ 175 product(bool, NeverTenure, false, \ 176 "Never tenure objects in eden, may tenure on overflow " \ 177 "(ParallelGC only)") \ 178 \ 179 product(bool, ScavengeBeforeFullGC, true, \ 180 "Scavenge youngest generation before each full GC.") \ 181 \ 182 product(bool, ExplicitGCInvokesConcurrent, false, \ 183 "A System.gc() request invokes a concurrent collection; " \ 184 "(effective only when using concurrent collectors)") \ 185 \ 186 product(bool, GCLockerInvokesConcurrent, false, \ 187 "The exit of a JNI critical section necessitating a scavenge, " \ 188 "also kicks off a background concurrent collection") \ 189 \ 190 product(uintx, GCLockerEdenExpansionPercent, 5, \ 191 "How much the GC can expand the eden by while the GC locker " \ 192 "is active (as a percentage)") \ 193 range(0, 100) \ 194 \ 195 diagnostic(uintx, GCLockerRetryAllocationCount, 2, \ 196 "Number of times to retry allocations when " \ 197 "blocked by the GC locker") \ 198 range(0, max_uintx) \ 199 \ 200 product(uintx, ParallelGCBufferWastePct, 10, \ 201 "Wasted fraction of parallel allocation buffer") \ 202 range(0, 100) \ 203 \ 204 product(uintx, TargetPLABWastePct, 10, \ 205 "Target wasted space in last buffer as percent of overall " \ 206 "allocation") \ 207 range(1, 100) \ 208 \ 209 product(uintx, PLABWeight, 75, \ 210 "Percentage (0-100) used to weight the current sample when " \ 211 "computing exponentially decaying average for ResizePLAB") \ 212 range(0, 100) \ 213 \ 214 product(bool, ResizePLAB, true, \ 215 "Dynamically resize (survivor space) promotion LAB's") \ 216 \ 217 product(int, ParGCArrayScanChunk, 50, \ 218 "Scan a subset of object array and push remainder, if array is " \ 219 "bigger than this") \ 220 range(1, max_jint/3) \ 221 \ 222 product(uintx, OldPLABWeight, 50, \ 223 "Percentage (0-100) used to weight the current sample when " \ 224 "computing exponentially decaying average for resizing " \ 225 "OldPLABSize") \ 226 range(0, 100) \ 227 \ 228 product(bool, ResizeOldPLAB, true, \ 229 "Dynamically resize (old gen) promotion LAB's") \ 230 \ 231 product(bool, AlwaysPreTouch, false, \ 232 "Force all freshly committed pages to be pre-touched") \ 233 \ 234 product(size_t, PreTouchParallelChunkSize, 1 * G, \ 235 "Per-thread chunk size for parallel memory pre-touch.") \ 236 range(1, SIZE_MAX / 2) \ 237 \ 238 /* where does the range max value of (max_jint - 1) come from? */ \ 239 product(size_t, MarkStackSizeMax, NOT_LP64(4*M) LP64_ONLY(512*M), \ 240 "Maximum size of marking stack") \ 241 range(1, (max_jint - 1)) \ 242 \ 243 product(size_t, MarkStackSize, NOT_LP64(32*K) LP64_ONLY(4*M), \ 244 "Size of marking stack") \ 245 constraint(MarkStackSizeConstraintFunc,AfterErgo) \ 246 \ 247 develop(bool, VerifyBlockOffsetArray, false, \ 248 "Do (expensive) block offset array verification") \ 249 \ 250 diagnostic(bool, BlockOffsetArrayUseUnallocatedBlock, false, \ 251 "Maintain _unallocated_block in BlockOffsetArray " \ 252 "(currently applicable only to CMS collector)") \ 253 \ 254 product(intx, RefDiscoveryPolicy, 0, \ 255 "Select type of reference discovery policy: " \ 256 "reference-based(0) or referent-based(1)") \ 257 range(ReferenceProcessor::DiscoveryPolicyMin, \ 258 ReferenceProcessor::DiscoveryPolicyMax) \ 259 \ 260 product(bool, ParallelRefProcEnabled, false, \ 261 "Enable parallel reference processing whenever possible") \ 262 \ 263 product(bool, ParallelRefProcBalancingEnabled, true, \ 264 "Enable balancing of reference processing queues") \ 265 \ 266 product(uintx, InitiatingHeapOccupancyPercent, 45, \ 267 "The percent occupancy (IHOP) of the current old generation " \ 268 "capacity above which a concurrent mark cycle will be initiated " \ 269 "Its value may change over time if adaptive IHOP is enabled, " \ 270 "otherwise the value remains constant. " \ 271 "In the latter case a value of 0 will result as frequent as " \ 272 "possible concurrent marking cycles. A value of 100 disables " \ 273 "concurrent marking. " \ 274 "Fragmentation waste in the old generation is not considered " \ 275 "free space in this calculation. (G1 collector only)") \ 276 range(0, 100) \ 277 \ 278 notproduct(bool, ScavengeALot, false, \ 279 "Force scavenge at every Nth exit from the runtime system " \ 280 "(N=ScavengeALotInterval)") \ 281 \ 282 develop(bool, FullGCALot, false, \ 283 "Force full gc at every Nth exit from the runtime system " \ 284 "(N=FullGCALotInterval)") \ 285 \ 286 notproduct(bool, GCALotAtAllSafepoints, false, \ 287 "Enforce ScavengeALot/GCALot at all potential safepoints") \ 288 \ 289 notproduct(bool, PromotionFailureALot, false, \ 290 "Use promotion failure handling on every youngest generation " \ 291 "collection") \ 292 \ 293 develop(uintx, PromotionFailureALotCount, 1000, \ 294 "Number of promotion failures occurring at PLAB " \ 295 "refill attempts (ParNew) or promotion attempts " \ 296 "(other young collectors)") \ 297 \ 298 develop(uintx, PromotionFailureALotInterval, 5, \ 299 "Total collections between promotion failures a lot") \ 300 \ 301 experimental(uintx, WorkStealingSleepMillis, 1, \ 302 "Sleep time when sleep is used for yields") \ 303 \ 304 experimental(uintx, WorkStealingYieldsBeforeSleep, 5000, \ 305 "Number of yields before a sleep is done during work stealing") \ 306 \ 307 experimental(uintx, WorkStealingHardSpins, 4096, \ 308 "Number of iterations in a spin loop between checks on " \ 309 "time out of hard spin") \ 310 \ 311 experimental(uintx, WorkStealingSpinToYieldRatio, 10, \ 312 "Ratio of hard spins to calls to yield") \ 313 \ 314 develop(uintx, ObjArrayMarkingStride, 2048, \ 315 "Number of object array elements to push onto the marking stack " \ 316 "before pushing a continuation entry") \ 317 \ 318 develop(bool, MetadataAllocationFailALot, false, \ 319 "Fail metadata allocations at intervals controlled by " \ 320 "MetadataAllocationFailALotInterval") \ 321 \ 322 develop(uintx, MetadataAllocationFailALotInterval, 1000, \ 323 "Metadata allocation failure a lot interval") \ 324 \ 325 notproduct(bool, ExecuteInternalVMTests, false, \ 326 "Enable execution of internal VM tests") \ 327 \ 328 notproduct(bool, VerboseInternalVMTests, false, \ 329 "Turn on logging for internal VM tests.") \ 330 \ 331 product(bool, ExecutingUnitTests, false, \ 332 "Whether the JVM is running unit tests or not") \ 333 \ 334 product_pd(bool, UseTLAB, "Use thread-local object allocation") \ 335 \ 336 product_pd(bool, ResizeTLAB, \ 337 "Dynamically resize TLAB size for threads") \ 338 \ 339 product(bool, ZeroTLAB, false, \ 340 "Zero out the newly created TLAB") \ 341 \ 342 product(bool, TLABStats, true, \ 343 "Provide more detailed and expensive TLAB statistics.") \ 344 \ 345 product_pd(bool, NeverActAsServerClassMachine, \ 346 "Never act like a server-class machine") \ 347 \ 348 product(bool, AlwaysActAsServerClassMachine, false, \ 349 "Always act like a server-class machine") \ 350 \ 351 product_pd(uint64_t, MaxRAM, \ 352 "Real memory size (in bytes) used to set maximum heap size") \ 353 range(0, 0XFFFFFFFFFFFFFFFF) \ 354 \ 355 product(bool, AggressiveHeap, false, \ 356 "Optimize heap options for long-running memory intensive apps") \ 357 \ 358 product(size_t, ErgoHeapSizeLimit, 0, \ 359 "Maximum ergonomically set heap size (in bytes); zero means use " \ 360 "MaxRAM * MaxRAMPercentage / 100") \ 361 range(0, max_uintx) \ 362 \ 363 product(uintx, MaxRAMFraction, 4, \ 364 "Maximum fraction (1/n) of real memory used for maximum heap " \ 365 "size. " \ 366 "Deprecated, use MaxRAMPercentage instead") \ 367 range(1, max_uintx) \ 368 \ 369 product(uintx, MinRAMFraction, 2, \ 370 "Minimum fraction (1/n) of real memory used for maximum heap " \ 371 "size on systems with small physical memory size. " \ 372 "Deprecated, use MinRAMPercentage instead") \ 373 range(1, max_uintx) \ 374 \ 375 product(uintx, InitialRAMFraction, 64, \ 376 "Fraction (1/n) of real memory used for initial heap size. " \ 377 "Deprecated, use InitialRAMPercentage instead") \ 378 range(1, max_uintx) \ 379 \ 380 product(double, MaxRAMPercentage, 25.0, \ 381 "Maximum percentage of real memory used for maximum heap size") \ 382 range(0.0, 100.0) \ 383 \ 384 product(double, MinRAMPercentage, 50.0, \ 385 "Minimum percentage of real memory used for maximum heap" \ 386 "size on systems with small physical memory size") \ 387 range(0.0, 100.0) \ 388 \ 389 product(double, InitialRAMPercentage, 1.5625, \ 390 "Percentage of real memory used for initial heap size") \ 391 range(0.0, 100.0) \ 392 \ 393 product(int, ActiveProcessorCount, -1, \ 394 "Specify the CPU count the VM should use and report as active") \ 395 \ 396 develop(uintx, MaxVirtMemFraction, 2, \ 397 "Maximum fraction (1/n) of virtual memory used for ergonomically "\ 398 "determining maximum heap size") \ 399 \ 400 product(bool, UseAdaptiveSizePolicy, true, \ 401 "Use adaptive generation sizing policies") \ 402 \ 403 product(bool, UsePSAdaptiveSurvivorSizePolicy, true, \ 404 "Use adaptive survivor sizing policies") \ 405 \ 406 product(bool, UseAdaptiveGenerationSizePolicyAtMinorCollection, true, \ 407 "Use adaptive young-old sizing policies at minor collections") \ 408 \ 409 product(bool, UseAdaptiveGenerationSizePolicyAtMajorCollection, true, \ 410 "Use adaptive young-old sizing policies at major collections") \ 411 \ 412 product(bool, UseAdaptiveSizePolicyWithSystemGC, false, \ 413 "Include statistics from System.gc() for adaptive size policy") \ 414 \ 415 product(bool, UseAdaptiveGCBoundary, false, \ 416 "Allow young-old boundary to move") \ 417 \ 418 develop(intx, PSAdaptiveSizePolicyResizeVirtualSpaceAlot, -1, \ 419 "Resize the virtual spaces of the young or old generations") \ 420 range(-1, 1) \ 421 \ 422 product(uintx, AdaptiveSizeThroughPutPolicy, 0, \ 423 "Policy for changing generation size for throughput goals") \ 424 range(0, 1) \ 425 \ 426 product(uintx, AdaptiveSizePolicyInitializingSteps, 20, \ 427 "Number of steps where heuristics is used before data is used") \ 428 range(0, max_uintx) \ 429 \ 430 develop(uintx, AdaptiveSizePolicyReadyThreshold, 5, \ 431 "Number of collections before the adaptive sizing is started") \ 432 \ 433 product(uintx, AdaptiveSizePolicyOutputInterval, 0, \ 434 "Collection interval for printing information; zero means never") \ 435 range(0, max_uintx) \ 436 \ 437 product(bool, UseAdaptiveSizePolicyFootprintGoal, true, \ 438 "Use adaptive minimum footprint as a goal") \ 439 \ 440 product(uintx, AdaptiveSizePolicyWeight, 10, \ 441 "Weight given to exponential resizing, between 0 and 100") \ 442 range(0, 100) \ 443 \ 444 product(uintx, AdaptiveTimeWeight, 25, \ 445 "Weight given to time in adaptive policy, between 0 and 100") \ 446 range(0, 100) \ 447 \ 448 product(uintx, PausePadding, 1, \ 449 "How much buffer to keep for pause time") \ 450 range(0, max_juint) \ 451 \ 452 product(uintx, PromotedPadding, 3, \ 453 "How much buffer to keep for promotion failure") \ 454 range(0, max_juint) \ 455 \ 456 product(uintx, SurvivorPadding, 3, \ 457 "How much buffer to keep for survivor overflow") \ 458 range(0, max_juint) \ 459 \ 460 product(uintx, ThresholdTolerance, 10, \ 461 "Allowed collection cost difference between generations") \ 462 range(0, 100) \ 463 \ 464 product(uintx, AdaptiveSizePolicyCollectionCostMargin, 50, \ 465 "If collection costs are within margin, reduce both by full " \ 466 "delta") \ 467 range(0, 100) \ 468 \ 469 product(uintx, YoungGenerationSizeIncrement, 20, \ 470 "Adaptive size percentage change in young generation") \ 471 range(0, 100) \ 472 \ 473 product(uintx, YoungGenerationSizeSupplement, 80, \ 474 "Supplement to YoungedGenerationSizeIncrement used at startup") \ 475 range(0, 100) \ 476 \ 477 product(uintx, YoungGenerationSizeSupplementDecay, 8, \ 478 "Decay factor to YoungedGenerationSizeSupplement") \ 479 range(1, max_uintx) \ 480 \ 481 product(uintx, TenuredGenerationSizeIncrement, 20, \ 482 "Adaptive size percentage change in tenured generation") \ 483 range(0, 100) \ 484 \ 485 product(uintx, TenuredGenerationSizeSupplement, 80, \ 486 "Supplement to TenuredGenerationSizeIncrement used at startup") \ 487 range(0, 100) \ 488 \ 489 product(uintx, TenuredGenerationSizeSupplementDecay, 2, \ 490 "Decay factor to TenuredGenerationSizeIncrement") \ 491 range(1, max_uintx) \ 492 \ 493 product(uintx, MaxGCPauseMillis, max_uintx - 1, \ 494 "Adaptive size policy maximum GC pause time goal in millisecond, "\ 495 "or (G1 Only) the maximum GC time per MMU time slice") \ 496 range(1, max_uintx - 1) \ 497 constraint(MaxGCPauseMillisConstraintFunc,AfterErgo) \ 498 \ 499 product(uintx, GCPauseIntervalMillis, 0, \ 500 "Time slice for MMU specification") \ 501 constraint(GCPauseIntervalMillisConstraintFunc,AfterErgo) \ 502 \ 503 product(uintx, MaxGCMinorPauseMillis, max_uintx, \ 504 "Adaptive size policy maximum GC minor pause time goal " \ 505 "in millisecond") \ 506 range(0, max_uintx) \ 507 \ 508 product(uintx, GCTimeRatio, 99, \ 509 "Adaptive size policy application time to GC time ratio") \ 510 range(0, max_juint) \ 511 \ 512 product(uintx, AdaptiveSizeDecrementScaleFactor, 4, \ 513 "Adaptive size scale down factor for shrinking") \ 514 range(1, max_uintx) \ 515 \ 516 product(bool, UseAdaptiveSizeDecayMajorGCCost, true, \ 517 "Adaptive size decays the major cost for long major intervals") \ 518 \ 519 product(uintx, AdaptiveSizeMajorGCDecayTimeScale, 10, \ 520 "Time scale over which major costs decay") \ 521 range(0, max_uintx) \ 522 \ 523 product(uintx, MinSurvivorRatio, 3, \ 524 "Minimum ratio of young generation/survivor space size") \ 525 range(3, max_uintx) \ 526 \ 527 product(uintx, InitialSurvivorRatio, 8, \ 528 "Initial ratio of young generation/survivor space size") \ 529 range(0, max_uintx) \ 530 \ 531 product(size_t, BaseFootPrintEstimate, 256*M, \ 532 "Estimate of footprint other than Java Heap") \ 533 range(0, max_uintx) \ 534 \ 535 product(bool, UseGCOverheadLimit, true, \ 536 "Use policy to limit of proportion of time spent in GC " \ 537 "before an OutOfMemory error is thrown") \ 538 \ 539 product(uintx, GCTimeLimit, 98, \ 540 "Limit of the proportion of time spent in GC before " \ 541 "an OutOfMemoryError is thrown (used with GCHeapFreeLimit)") \ 542 range(0, 100) \ 543 \ 544 product(uintx, GCHeapFreeLimit, 2, \ 545 "Minimum percentage of free space after a full GC before an " \ 546 "OutOfMemoryError is thrown (used with GCTimeLimit)") \ 547 range(0, 100) \ 548 \ 549 develop(uintx, AdaptiveSizePolicyGCTimeLimitThreshold, 5, \ 550 "Number of consecutive collections before gc time limit fires") \ 551 range(1, max_uintx) \ 552 \ 553 product(intx, PrefetchCopyIntervalInBytes, -1, \ 554 "How far ahead to prefetch destination area (<= 0 means off)") \ 555 range(-1, max_jint) \ 556 \ 557 product(intx, PrefetchScanIntervalInBytes, -1, \ 558 "How far ahead to prefetch scan area (<= 0 means off)") \ 559 range(-1, max_jint) \ 560 \ 561 product(intx, PrefetchFieldsAhead, -1, \ 562 "How many fields ahead to prefetch in oop scan (<= 0 means off)") \ 563 range(-1, max_jint) \ 564 \ 565 diagnostic(bool, VerifyDuringStartup, false, \ 566 "Verify memory system before executing any Java code " \ 567 "during VM initialization") \ 568 \ 569 diagnostic(bool, VerifyBeforeExit, trueInDebug, \ 570 "Verify system before exiting") \ 571 \ 572 diagnostic(bool, VerifyBeforeGC, false, \ 573 "Verify memory system before GC") \ 574 \ 575 diagnostic(bool, VerifyAfterGC, false, \ 576 "Verify memory system after GC") \ 577 \ 578 diagnostic(bool, VerifyDuringGC, false, \ 579 "Verify memory system during GC (between phases)") \ 580 \ 581 diagnostic(ccstrlist, VerifyGCType, "", \ 582 "GC type(s) to verify when Verify*GC is enabled." \ 583 "Available types are collector specific.") \ 584 \ 585 diagnostic(ccstrlist, VerifySubSet, "", \ 586 "Memory sub-systems to verify when Verify*GC flag(s) " \ 587 "are enabled. One or more sub-systems can be specified " \ 588 "in a comma separated string. Sub-systems are: " \ 589 "threads, heap, symbol_table, string_table, codecache, " \ 590 "dictionary, classloader_data_graph, metaspace, jni_handles, " \ 591 "codecache_oops") \ 592 \ 593 diagnostic(bool, GCParallelVerificationEnabled, true, \ 594 "Enable parallel memory system verification") \ 595 \ 596 diagnostic(bool, DeferInitialCardMark, false, \ 597 "When +ReduceInitialCardMarks, explicitly defer any that " \ 598 "may arise from new_pre_store_barrier") \ 599 \ 600 product(bool, UseCondCardMark, false, \ 601 "Check for already marked card before updating card table") \ 602 \ 603 diagnostic(bool, VerifyRememberedSets, false, \ 604 "Verify GC remembered sets") \ 605 \ 606 diagnostic(bool, VerifyObjectStartArray, true, \ 607 "Verify GC object start array if verify before/after") \ 608 \ 609 product(bool, DisableExplicitGC, false, \ 610 "Ignore calls to System.gc()") \ 611 \ 612 product(bool, BindGCTaskThreadsToCPUs, false, \ 613 "Bind GCTaskThreads to CPUs if possible") \ 614 \ 615 product(bool, UseGCTaskAffinity, false, \ 616 "Use worker affinity when asking for GCTasks") \ 617 \ 618 product(bool, PrintGC, false, \ 619 "Print message at garbage collection. " \ 620 "Deprecated, use -Xlog:gc instead.") \ 621 \ 622 product(bool, PrintGCDetails, false, \ 623 "Print more details at garbage collection. " \ 624 "Deprecated, use -Xlog:gc* instead.") \ 625 \ 626 develop(intx, ConcGCYieldTimeout, 0, \ 627 "If non-zero, assert that GC threads yield within this " \ 628 "number of milliseconds") \ 629 range(0, max_intx) \ 630 \ 631 notproduct(intx, ScavengeALotInterval, 1, \ 632 "Interval between which scavenge will occur with +ScavengeALot") \ 633 \ 634 notproduct(intx, FullGCALotInterval, 1, \ 635 "Interval between which full gc will occur with +FullGCALot") \ 636 \ 637 notproduct(intx, FullGCALotStart, 0, \ 638 "For which invocation to start FullGCAlot") \ 639 \ 640 notproduct(intx, FullGCALotDummies, 32*K, \ 641 "Dummy object allocated with +FullGCALot, forcing all objects " \ 642 "to move") \ 643 \ 644 /* gc parameters */ \ 645 product(size_t, InitialHeapSize, 0, \ 646 "Initial heap size (in bytes); zero means use ergonomics") \ 647 constraint(InitialHeapSizeConstraintFunc,AfterErgo) \ 648 \ 649 product(size_t, MaxHeapSize, ScaleForWordSize(96*M), \ 650 "Maximum heap size (in bytes)") \ 651 constraint(MaxHeapSizeConstraintFunc,AfterErgo) \ 652 \ 653 product(size_t, OldSize, ScaleForWordSize(4*M), \ 654 "Initial tenured generation size (in bytes)") \ 655 range(0, max_uintx) \ 656 \ 657 product(size_t, NewSize, ScaleForWordSize(1*M), \ 658 "Initial new generation size (in bytes)") \ 659 constraint(NewSizeConstraintFunc,AfterErgo) \ 660 \ 661 product(size_t, MaxNewSize, max_uintx, \ 662 "Maximum new generation size (in bytes), max_uintx means set " \ 663 "ergonomically") \ 664 range(0, max_uintx) \ 665 \ 666 product_pd(size_t, HeapBaseMinAddress, \ 667 "OS specific low limit for heap base address") \ 668 constraint(HeapBaseMinAddressConstraintFunc,AfterErgo) \ 669 \ 670 product(size_t, PretenureSizeThreshold, 0, \ 671 "Maximum size in bytes of objects allocated in DefNew " \ 672 "generation; zero means no maximum") \ 673 range(0, max_uintx) \ 674 \ 675 product(size_t, MinTLABSize, 2*K, \ 676 "Minimum allowed TLAB size (in bytes)") \ 677 range(1, max_uintx/2) \ 678 constraint(MinTLABSizeConstraintFunc,AfterMemoryInit) \ 679 \ 680 product(size_t, TLABSize, 0, \ 681 "Starting TLAB size (in bytes); zero means set ergonomically") \ 682 constraint(TLABSizeConstraintFunc,AfterMemoryInit) \ 683 \ 684 product(size_t, YoungPLABSize, 4096, \ 685 "Size of young gen promotion LAB's (in HeapWords)") \ 686 constraint(YoungPLABSizeConstraintFunc,AfterMemoryInit) \ 687 \ 688 product(size_t, OldPLABSize, 1024, \ 689 "Size of old gen promotion LAB's (in HeapWords), or Number " \ 690 "of blocks to attempt to claim when refilling CMS LAB's") \ 691 constraint(OldPLABSizeConstraintFunc,AfterMemoryInit) \ 692 \ 693 product(uintx, TLABAllocationWeight, 35, \ 694 "Allocation averaging weight") \ 695 range(0, 100) \ 696 \ 697 /* Limit the lower bound of this flag to 1 as it is used */ \ 698 /* in a division expression. */ \ 699 product(uintx, TLABWasteTargetPercent, 1, \ 700 "Percentage of Eden that can be wasted") \ 701 range(1, 100) \ 702 \ 703 product(uintx, TLABRefillWasteFraction, 64, \ 704 "Maximum TLAB waste at a refill (internal fragmentation)") \ 705 range(1, max_juint) \ 706 \ 707 product(uintx, TLABWasteIncrement, 4, \ 708 "Increment allowed waste at slow allocation") \ 709 range(0, max_jint) \ 710 constraint(TLABWasteIncrementConstraintFunc,AfterMemoryInit) \ 711 \ 712 product(uintx, SurvivorRatio, 8, \ 713 "Ratio of eden/survivor space size") \ 714 range(1, max_uintx-2) \ 715 constraint(SurvivorRatioConstraintFunc,AfterMemoryInit) \ 716 \ 717 product(uintx, NewRatio, 2, \ 718 "Ratio of old/new generation sizes") \ 719 range(0, max_uintx-1) \ 720 \ 721 product_pd(size_t, NewSizeThreadIncrease, \ 722 "Additional size added to desired new generation size per " \ 723 "non-daemon thread (in bytes)") \ 724 range(0, max_uintx) \ 725 \ 726 product(uintx, QueuedAllocationWarningCount, 0, \ 727 "Number of times an allocation that queues behind a GC " \ 728 "will retry before printing a warning") \ 729 range(0, max_uintx) \ 730 \ 731 diagnostic(uintx, VerifyGCStartAt, 0, \ 732 "GC invoke count where +VerifyBefore/AfterGC kicks in") \ 733 range(0, max_uintx) \ 734 \ 735 diagnostic(intx, VerifyGCLevel, 0, \ 736 "Generation level at which to start +VerifyBefore/AfterGC") \ 737 range(0, 1) \ 738 \ 739 product(uintx, MaxTenuringThreshold, 15, \ 740 "Maximum value for tenuring threshold") \ 741 range(0, markOopDesc::max_age + 1) \ 742 constraint(MaxTenuringThresholdConstraintFunc,AfterErgo) \ 743 \ 744 product(uintx, InitialTenuringThreshold, 7, \ 745 "Initial value for tenuring threshold") \ 746 range(0, markOopDesc::max_age + 1) \ 747 constraint(InitialTenuringThresholdConstraintFunc,AfterErgo) \ 748 \ 749 product(uintx, TargetSurvivorRatio, 50, \ 750 "Desired percentage of survivor space used after scavenge") \ 751 range(0, 100) \ 752 \ 753 product(uintx, MarkSweepDeadRatio, 5, \ 754 "Percentage (0-100) of the old gen allowed as dead wood. " \ 755 "Serial mark sweep treats this as both the minimum and maximum " \ 756 "value. " \ 757 "CMS uses this value only if it falls back to mark sweep. " \ 758 "Par compact uses a variable scale based on the density of the " \ 759 "generation and treats this as the maximum value when the heap " \ 760 "is either completely full or completely empty. Par compact " \ 761 "also has a smaller default value; see arguments.cpp.") \ 762 range(0, 100) \ 763 \ 764 product(uint, MarkSweepAlwaysCompactCount, 4, \ 765 "How often should we fully compact the heap (ignoring the dead " \ 766 "space parameters)") \ 767 range(1, max_juint) \ 768 \ 769 develop(uintx, GCExpandToAllocateDelayMillis, 0, \ 770 "Delay between expansion and allocation (in milliseconds)") \ 771 \ 772 product(uintx, GCDrainStackTargetSize, 64, \ 773 "Number of entries we will try to leave on the stack " \ 774 "during parallel gc") \ 775 range(0, max_juint) 776 777 #endif // SHARE_GC_SHARED_GC_GLOBALS_HPP