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_CMS_CMS_GLOBALS_HPP 26 #define SHARE_GC_CMS_CMS_GLOBALS_HPP 27 28 #define GC_CMS_FLAGS(develop, \ 29 develop_pd, \ 30 product, \ 31 product_pd, \ 32 diagnostic, \ 33 diagnostic_pd, \ 34 experimental, \ 35 notproduct, \ 36 manageable, \ 37 product_rw, \ 38 lp64_product, \ 39 range, \ 40 constraint, \ 41 writeable) \ 42 product(bool, UseCMSBestFit, true, \ 43 "Use CMS best fit allocation strategy") \ 44 \ 45 product(size_t, CMSOldPLABMax, 1024, \ 46 "Maximum size of CMS gen promotion LAB caches per worker " \ 47 "per block size") \ 48 range(1, max_uintx) \ 49 constraint(CMSOldPLABMaxConstraintFunc,AfterMemoryInit) \ 50 \ 51 product(size_t, CMSOldPLABMin, 16, \ 52 "Minimum size of CMS gen promotion LAB caches per worker " \ 53 "per block size") \ 54 range(1, max_uintx) \ 55 constraint(CMSOldPLABMinConstraintFunc,AfterMemoryInit) \ 56 \ 57 product(uintx, CMSOldPLABNumRefills, 4, \ 58 "Nominal number of refills of CMS gen promotion LAB cache " \ 59 "per worker per block size") \ 60 range(1, max_uintx) \ 61 \ 62 product(bool, CMSOldPLABResizeQuicker, false, \ 63 "React on-the-fly during a scavenge to a sudden " \ 64 "change in block demand rate") \ 65 \ 66 product(uintx, CMSOldPLABToleranceFactor, 4, \ 67 "The tolerance of the phase-change detector for on-the-fly " \ 68 "PLAB resizing during a scavenge") \ 69 range(1, max_uintx) \ 70 \ 71 product(uintx, CMSOldPLABReactivityFactor, 2, \ 72 "The gain in the feedback loop for on-the-fly PLAB resizing " \ 73 "during a scavenge") \ 74 range(1, max_uintx) \ 75 \ 76 product_pd(size_t, CMSYoungGenPerWorker, \ 77 "The maximum size of young gen chosen by default per GC worker " \ 78 "thread available") \ 79 range(1, max_uintx) \ 80 \ 81 product(uintx, CMSIncrementalSafetyFactor, 10, \ 82 "Percentage (0-100) used to add conservatism when computing the " \ 83 "duty cycle") \ 84 range(0, 100) \ 85 \ 86 product(uintx, CMSExpAvgFactor, 50, \ 87 "Percentage (0-100) used to weight the current sample when " \ 88 "computing exponential averages for CMS statistics") \ 89 range(0, 100) \ 90 \ 91 product(uintx, CMS_FLSWeight, 75, \ 92 "Percentage (0-100) used to weight the current sample when " \ 93 "computing exponentially decaying averages for CMS FLS " \ 94 "statistics") \ 95 range(0, 100) \ 96 \ 97 product(uintx, CMS_FLSPadding, 1, \ 98 "The multiple of deviation from mean to use for buffering " \ 99 "against volatility in free list demand") \ 100 range(0, max_juint) \ 101 \ 102 product(uintx, FLSCoalescePolicy, 2, \ 103 "CMS: aggressiveness level for coalescing, increasing " \ 104 "from 0 to 4") \ 105 range(0, 4) \ 106 \ 107 product(bool, FLSAlwaysCoalesceLarge, false, \ 108 "CMS: larger free blocks are always available for coalescing") \ 109 \ 110 product(double, FLSLargestBlockCoalesceProximity, 0.99, \ 111 "CMS: the smaller the percentage the greater the coalescing " \ 112 "force") \ 113 range(0.0, 1.0) \ 114 \ 115 product(double, CMSSmallCoalSurplusPercent, 1.05, \ 116 "CMS: the factor by which to inflate estimated demand of small " \ 117 "block sizes to prevent coalescing with an adjoining block") \ 118 range(0.0, DBL_MAX) \ 119 \ 120 product(double, CMSLargeCoalSurplusPercent, 0.95, \ 121 "CMS: the factor by which to inflate estimated demand of large " \ 122 "block sizes to prevent coalescing with an adjoining block") \ 123 range(0.0, DBL_MAX) \ 124 \ 125 product(double, CMSSmallSplitSurplusPercent, 1.10, \ 126 "CMS: the factor by which to inflate estimated demand of small " \ 127 "block sizes to prevent splitting to supply demand for smaller " \ 128 "blocks") \ 129 range(0.0, DBL_MAX) \ 130 \ 131 product(double, CMSLargeSplitSurplusPercent, 1.00, \ 132 "CMS: the factor by which to inflate estimated demand of large " \ 133 "block sizes to prevent splitting to supply demand for smaller " \ 134 "blocks") \ 135 range(0.0, DBL_MAX) \ 136 \ 137 product(bool, CMSExtrapolateSweep, false, \ 138 "CMS: cushion for block demand during sweep") \ 139 \ 140 product(uintx, CMS_SweepWeight, 75, \ 141 "Percentage (0-100) used to weight the current sample when " \ 142 "computing exponentially decaying average for inter-sweep " \ 143 "duration") \ 144 range(0, 100) \ 145 \ 146 product(uintx, CMS_SweepPadding, 1, \ 147 "The multiple of deviation from mean to use for buffering " \ 148 "against volatility in inter-sweep duration") \ 149 range(0, max_juint) \ 150 \ 151 product(uintx, CMS_SweepTimerThresholdMillis, 10, \ 152 "Skip block flux-rate sampling for an epoch unless inter-sweep " \ 153 "duration exceeds this threshold in milliseconds") \ 154 range(0, max_uintx) \ 155 \ 156 product(bool, CMSClassUnloadingEnabled, true, \ 157 "Whether class unloading enabled when using CMS GC") \ 158 \ 159 product(uintx, CMSClassUnloadingMaxInterval, 0, \ 160 "When CMS class unloading is enabled, the maximum CMS cycle " \ 161 "count for which classes may not be unloaded") \ 162 range(0, max_uintx) \ 163 \ 164 product(uintx, CMSIndexedFreeListReplenish, 4, \ 165 "Replenish an indexed free list with this number of chunks") \ 166 range(1, max_uintx) \ 167 \ 168 product(bool, CMSReplenishIntermediate, true, \ 169 "Replenish all intermediate free-list caches") \ 170 \ 171 product(bool, CMSSplitIndexedFreeListBlocks, true, \ 172 "When satisfying batched demand, split blocks from the " \ 173 "IndexedFreeList whose size is a multiple of requested size") \ 174 \ 175 product(bool, CMSLoopWarn, false, \ 176 "Warn in case of excessive CMS looping") \ 177 \ 178 notproduct(bool, CMSMarkStackOverflowALot, false, \ 179 "Simulate frequent marking stack / work queue overflow") \ 180 \ 181 notproduct(uintx, CMSMarkStackOverflowInterval, 1000, \ 182 "An \"interval\" counter that determines how frequently " \ 183 "to simulate overflow; a smaller number increases frequency") \ 184 \ 185 product(uintx, CMSMaxAbortablePrecleanLoops, 0, \ 186 "Maximum number of abortable preclean iterations, if > 0") \ 187 range(0, max_uintx) \ 188 \ 189 product(intx, CMSMaxAbortablePrecleanTime, 5000, \ 190 "Maximum time in abortable preclean (in milliseconds)") \ 191 range(0, max_intx) \ 192 \ 193 product(uintx, CMSAbortablePrecleanMinWorkPerIteration, 100, \ 194 "Nominal minimum work per abortable preclean iteration") \ 195 range(0, max_uintx) \ 196 \ 197 manageable(intx, CMSAbortablePrecleanWaitMillis, 100, \ 198 "Time that we sleep between iterations when not given " \ 199 "enough work per iteration") \ 200 range(0, max_intx) \ 201 \ 202 /* 4096 = CardTable::card_size_in_words * BitsPerWord */ \ 203 product(size_t, CMSRescanMultiple, 32, \ 204 "Size (in cards) of CMS parallel rescan task") \ 205 range(1, SIZE_MAX / 4096) \ 206 constraint(CMSRescanMultipleConstraintFunc,AfterMemoryInit) \ 207 \ 208 /* 4096 = CardTable::card_size_in_words * BitsPerWord */ \ 209 product(size_t, CMSConcMarkMultiple, 32, \ 210 "Size (in cards) of CMS concurrent MT marking task") \ 211 range(1, SIZE_MAX / 4096) \ 212 constraint(CMSConcMarkMultipleConstraintFunc,AfterMemoryInit) \ 213 \ 214 product(bool, CMSAbortSemantics, false, \ 215 "Whether abort-on-overflow semantics is implemented") \ 216 \ 217 product(bool, CMSParallelInitialMarkEnabled, true, \ 218 "Use the parallel initial mark.") \ 219 \ 220 product(bool, CMSParallelRemarkEnabled, true, \ 221 "Whether parallel remark enabled (only if ParNewGC)") \ 222 \ 223 product(bool, CMSParallelSurvivorRemarkEnabled, true, \ 224 "Whether parallel remark of survivor space " \ 225 "enabled (effective only if CMSParallelRemarkEnabled)") \ 226 \ 227 product(bool, CMSPLABRecordAlways, true, \ 228 "Always record survivor space PLAB boundaries (effective only " \ 229 "if CMSParallelSurvivorRemarkEnabled)") \ 230 \ 231 product(bool, CMSEdenChunksRecordAlways, true, \ 232 "Always record eden chunks used for the parallel initial mark " \ 233 "or remark of eden") \ 234 \ 235 product(bool, CMSConcurrentMTEnabled, true, \ 236 "Whether multi-threaded concurrent work enabled " \ 237 "(effective only if ParNewGC)") \ 238 \ 239 product(bool, CMSPrecleaningEnabled, true, \ 240 "Whether concurrent precleaning enabled") \ 241 \ 242 product(uintx, CMSPrecleanIter, 3, \ 243 "Maximum number of precleaning iteration passes") \ 244 range(0, 9) \ 245 \ 246 product(uintx, CMSPrecleanDenominator, 3, \ 247 "CMSPrecleanNumerator:CMSPrecleanDenominator yields convergence " \ 248 "ratio") \ 249 range(1, max_uintx) \ 250 constraint(CMSPrecleanDenominatorConstraintFunc,AfterErgo) \ 251 \ 252 product(uintx, CMSPrecleanNumerator, 2, \ 253 "CMSPrecleanNumerator:CMSPrecleanDenominator yields convergence " \ 254 "ratio") \ 255 range(0, max_uintx-1) \ 256 constraint(CMSPrecleanNumeratorConstraintFunc,AfterErgo) \ 257 \ 258 product(bool, CMSPrecleanRefLists1, true, \ 259 "Preclean ref lists during (initial) preclean phase") \ 260 \ 261 product(bool, CMSPrecleanRefLists2, false, \ 262 "Preclean ref lists during abortable preclean phase") \ 263 \ 264 product(bool, CMSPrecleanSurvivors1, false, \ 265 "Preclean survivors during (initial) preclean phase") \ 266 \ 267 product(bool, CMSPrecleanSurvivors2, true, \ 268 "Preclean survivors during abortable preclean phase") \ 269 \ 270 product(uintx, CMSPrecleanThreshold, 1000, \ 271 "Do not iterate again if number of dirty cards is less than this")\ 272 range(100, max_uintx) \ 273 \ 274 product(bool, CMSCleanOnEnter, true, \ 275 "Clean-on-enter optimization for reducing number of dirty cards") \ 276 \ 277 product(uintx, CMSRemarkVerifyVariant, 1, \ 278 "Choose variant (1,2) of verification following remark") \ 279 range(1, 2) \ 280 \ 281 product(size_t, CMSScheduleRemarkEdenSizeThreshold, 2*M, \ 282 "If Eden size is below this, do not try to schedule remark") \ 283 range(0, max_uintx) \ 284 \ 285 product(uintx, CMSScheduleRemarkEdenPenetration, 50, \ 286 "The Eden occupancy percentage (0-100) at which " \ 287 "to try and schedule remark pause") \ 288 range(0, 100) \ 289 \ 290 product(uintx, CMSScheduleRemarkSamplingRatio, 5, \ 291 "Start sampling eden top at least before young gen " \ 292 "occupancy reaches 1/<ratio> of the size at which " \ 293 "we plan to schedule remark") \ 294 range(1, max_uintx) \ 295 \ 296 product(uintx, CMSSamplingGrain, 16*K, \ 297 "The minimum distance between eden samples for CMS (see above)") \ 298 range(ObjectAlignmentInBytes, max_uintx) \ 299 constraint(CMSSamplingGrainConstraintFunc,AfterMemoryInit) \ 300 \ 301 product(bool, CMSScavengeBeforeRemark, false, \ 302 "Attempt scavenge before the CMS remark step") \ 303 \ 304 product(uintx, CMSWorkQueueDrainThreshold, 10, \ 305 "Don't drain below this size per parallel worker/thief") \ 306 range(1, max_juint) \ 307 constraint(CMSWorkQueueDrainThresholdConstraintFunc,AfterErgo) \ 308 \ 309 manageable(intx, CMSWaitDuration, 2000, \ 310 "Time in milliseconds that CMS thread waits for young GC") \ 311 range(min_jint, max_jint) \ 312 \ 313 develop(uintx, CMSCheckInterval, 1000, \ 314 "Interval in milliseconds that CMS thread checks if it " \ 315 "should start a collection cycle") \ 316 \ 317 product(bool, CMSYield, true, \ 318 "Yield between steps of CMS") \ 319 \ 320 product(size_t, CMSBitMapYieldQuantum, 10*M, \ 321 "Bitmap operations should process at most this many bits " \ 322 "between yields") \ 323 range(1, max_uintx) \ 324 constraint(CMSBitMapYieldQuantumConstraintFunc,AfterMemoryInit) \ 325 \ 326 product(bool, CMSPrintChunksInDump, false, \ 327 "If logging for the \"gc\" and \"promotion\" tags is enabled on" \ 328 "trace level include more detailed information about the" \ 329 "free chunks") \ 330 \ 331 product(bool, CMSPrintObjectsInDump, false, \ 332 "If logging for the \"gc\" and \"promotion\" tags is enabled on" \ 333 "trace level include more detailed information about the" \ 334 "allocated objects") \ 335 \ 336 diagnostic(bool, FLSVerifyAllHeapReferences, false, \ 337 "Verify that all references across the FLS boundary " \ 338 "are to valid objects") \ 339 \ 340 diagnostic(bool, FLSVerifyLists, false, \ 341 "Do lots of (expensive) FreeListSpace verification") \ 342 \ 343 diagnostic(bool, FLSVerifyIndexTable, false, \ 344 "Do lots of (expensive) FLS index table verification") \ 345 \ 346 product(uintx, CMSTriggerRatio, 80, \ 347 "Percentage of MinHeapFreeRatio in CMS generation that is " \ 348 "allocated before a CMS collection cycle commences") \ 349 range(0, 100) \ 350 \ 351 product(uintx, CMSBootstrapOccupancy, 50, \ 352 "Percentage CMS generation occupancy at which to " \ 353 "initiate CMS collection for bootstrapping collection stats") \ 354 range(0, 100) \ 355 \ 356 product(intx, CMSInitiatingOccupancyFraction, -1, \ 357 "Percentage CMS generation occupancy to start a CMS collection " \ 358 "cycle. A negative value means that CMSTriggerRatio is used") \ 359 range(min_intx, 100) \ 360 \ 361 manageable(intx, CMSTriggerInterval, -1, \ 362 "Commence a CMS collection cycle (at least) every so many " \ 363 "milliseconds (0 permanently, -1 disabled)") \ 364 range(-1, max_intx) \ 365 \ 366 product(bool, UseCMSInitiatingOccupancyOnly, false, \ 367 "Only use occupancy as a criterion for starting a CMS collection")\ 368 \ 369 product(uintx, CMSIsTooFullPercentage, 98, \ 370 "An absolute ceiling above which CMS will always consider the " \ 371 "unloading of classes when class unloading is enabled") \ 372 range(0, 100) \ 373 \ 374 develop(bool, CMSTestInFreeList, false, \ 375 "Check if the coalesced range is already in the " \ 376 "free lists as claimed") \ 377 \ 378 notproduct(bool, CMSVerifyReturnedBytes, false, \ 379 "Check that all the garbage collected was returned to the " \ 380 "free lists") \ 381 \ 382 diagnostic(bool, BindCMSThreadToCPU, false, \ 383 "Bind CMS Thread to CPU if possible") \ 384 \ 385 diagnostic(uintx, CPUForCMSThread, 0, \ 386 "When BindCMSThreadToCPU is true, the CPU to bind CMS thread to") \ 387 range(0, max_juint) \ 388 \ 389 product(uintx, CMSCoordinatorYieldSleepCount, 10, \ 390 "Number of times the coordinator GC thread will sleep while " \ 391 "yielding before giving up and resuming GC") \ 392 range(0, max_juint) \ 393 \ 394 product(uintx, CMSYieldSleepCount, 0, \ 395 "Number of times a GC thread (minus the coordinator) " \ 396 "will sleep while yielding before giving up and resuming GC") \ 397 range(0, max_juint) \ 398 \ 399 product(bool, ParGCUseLocalOverflow, false, \ 400 "Instead of a global overflow list, use local overflow stacks") \ 401 \ 402 product(bool, ParGCTrimOverflow, true, \ 403 "Eagerly trim the local overflow lists " \ 404 "(when ParGCUseLocalOverflow)") \ 405 \ 406 notproduct(bool, ParGCWorkQueueOverflowALot, false, \ 407 "Simulate work queue overflow in ParNew") \ 408 \ 409 notproduct(uintx, ParGCWorkQueueOverflowInterval, 1000, \ 410 "An `interval' counter that determines how frequently " \ 411 "we simulate overflow; a smaller number increases frequency") \ 412 \ 413 product(uintx, ParGCDesiredObjsFromOverflowList, 20, \ 414 "The desired number of objects to claim from the overflow list") \ 415 range(0, max_uintx) \ 416 \ 417 diagnostic(uintx, ParGCStridesPerThread, 2, \ 418 "The number of strides per worker thread that we divide up the " \ 419 "card table scanning work into") \ 420 range(1, max_uintx) \ 421 constraint(ParGCStridesPerThreadConstraintFunc,AfterErgo) \ 422 \ 423 diagnostic(intx, ParGCCardsPerStrideChunk, 256, \ 424 "The number of cards in each chunk of the parallel chunks used " \ 425 "during card table scanning") \ 426 range(1, max_intx) \ 427 constraint(ParGCCardsPerStrideChunkConstraintFunc,AfterMemoryInit) 428 429 #endif // SHARE_GC_CMS_CMS_GLOBALS_HPP