1 /* 2 * Copyright (c) 2001, 2019, 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_G1_G1_GLOBALS_HPP 26 #define SHARE_GC_G1_G1_GLOBALS_HPP 27 28 #include "runtime/globals_shared.hpp" 29 30 // 31 // Defines all globals flags used by the garbage-first compiler. 32 // 33 34 #define GC_G1_FLAGS(develop, \ 35 develop_pd, \ 36 product, \ 37 product_pd, \ 38 diagnostic, \ 39 diagnostic_pd, \ 40 experimental, \ 41 notproduct, \ 42 manageable, \ 43 product_rw, \ 44 lp64_product, \ 45 range, \ 46 constraint, \ 47 writeable) \ 48 \ 49 product(bool, G1UseAdaptiveIHOP, true, \ 50 "Adaptively adjust the initiating heap occupancy from the " \ 51 "initial value of InitiatingHeapOccupancyPercent. The policy " \ 52 "attempts to start marking in time based on application " \ 53 "behavior.") \ 54 \ 55 experimental(size_t, G1AdaptiveIHOPNumInitialSamples, 3, \ 56 "How many completed time periods from initial mark to first " \ 57 "mixed gc are required to use the input values for prediction " \ 58 "of the optimal occupancy to start marking.") \ 59 range(1, max_intx) \ 60 \ 61 product(uintx, G1ConfidencePercent, 50, \ 62 "Confidence level for MMU/pause predictions") \ 63 range(0, 100) \ 64 \ 65 diagnostic(intx, G1SummarizeRSetStatsPeriod, 0, \ 66 "The period (in number of GCs) at which we will generate " \ 67 "update buffer processing info " \ 68 "(0 means do not periodically generate this info); " \ 69 "it also requires that logging is enabled on the trace" \ 70 "level for gc+remset") \ 71 range(0, max_intx) \ 72 \ 73 product(double, G1ConcMarkStepDurationMillis, 10.0, \ 74 "Target duration of individual concurrent marking steps " \ 75 "in milliseconds.") \ 76 range(1.0, DBL_MAX) \ 77 \ 78 product(uint, G1RefProcDrainInterval, 1000, \ 79 "The number of discovered reference objects to process before " \ 80 "draining concurrent marking work queues.") \ 81 range(1, INT_MAX) \ 82 \ 83 experimental(bool, G1UseReferencePrecleaning, true, \ 84 "Concurrently preclean java.lang.ref.references instances " \ 85 "before the Remark pause.") \ 86 \ 87 experimental(double, G1LastPLABAverageOccupancy, 50.0, \ 88 "The expected average occupancy of the last PLAB in " \ 89 "percent.") \ 90 range(0.001, 100.0) \ 91 \ 92 product(size_t, G1SATBBufferSize, 1*K, \ 93 "Number of entries in an SATB log buffer.") \ 94 range(1, max_uintx) \ 95 \ 96 develop(intx, G1SATBProcessCompletedThreshold, 20, \ 97 "Number of completed buffers that triggers log processing.") \ 98 range(0, max_jint) \ 99 \ 100 product(uintx, G1SATBBufferEnqueueingThresholdPercent, 60, \ 101 "Before enqueueing them, each mutator thread tries to do some " \ 102 "filtering on the SATB buffers it generates. If post-filtering " \ 103 "the percentage of retained entries is over this threshold " \ 104 "the buffer will be enqueued for processing. A value of 0 " \ 105 "specifies that mutator threads should not do such filtering.") \ 106 range(0, 100) \ 107 \ 108 experimental(intx, G1ExpandByPercentOfAvailable, 20, \ 109 "When expanding, % of uncommitted space to claim.") \ 110 range(0, 100) \ 111 \ 112 product(size_t, G1UpdateBufferSize, 256, \ 113 "Size of an update buffer") \ 114 range(1, NOT_LP64(32*M) LP64_ONLY(1*G)) \ 115 \ 116 product(size_t, G1ConcRefinementYellowZone, 0, \ 117 "Number of enqueued update buffers that will " \ 118 "trigger concurrent processing. Will be selected ergonomically " \ 119 "by default.") \ 120 range(0, max_intx) \ 121 \ 122 product(size_t, G1ConcRefinementRedZone, 0, \ 123 "Maximum number of enqueued update buffers before mutator " \ 124 "threads start processing new ones instead of enqueueing them. " \ 125 "Will be selected ergonomically by default.") \ 126 range(0, max_intx) \ 127 \ 128 product(size_t, G1ConcRefinementGreenZone, 0, \ 129 "The number of update buffers that are left in the queue by the " \ 130 "concurrent processing threads. Will be selected ergonomically " \ 131 "by default.") \ 132 range(0, max_intx) \ 133 \ 134 product(uintx, G1ConcRefinementServiceIntervalMillis, 300, \ 135 "The last concurrent refinement thread wakes up every " \ 136 "specified number of milliseconds to do miscellaneous work.") \ 137 range(0, max_jint) \ 138 \ 139 product(size_t, G1ConcRefinementThresholdStep, 2, \ 140 "Each time the rset update queue increases by this amount " \ 141 "activate the next refinement thread if available. " \ 142 "The actual step size will be selected ergonomically by " \ 143 "default, with this value used to determine a lower bound.") \ 144 range(1, SIZE_MAX) \ 145 \ 146 product(intx, G1RSetUpdatingPauseTimePercent, 10, \ 147 "A target percentage of time that is allowed to be spend on " \ 148 "process RS update buffers during the collection pause.") \ 149 range(0, 100) \ 150 \ 151 product(bool, G1UseAdaptiveConcRefinement, true, \ 152 "Select green, yellow and red zones adaptively to meet the " \ 153 "the pause requirements.") \ 154 \ 155 product(size_t, G1ConcRSLogCacheSize, 10, \ 156 "Log base 2 of the length of conc RS hot-card cache.") \ 157 range(0, 27) \ 158 \ 159 product(uintx, G1ConcRSHotCardLimit, 4, \ 160 "The threshold that defines (>=) a hot card.") \ 161 range(0, max_jubyte) \ 162 \ 163 develop(intx, G1RSetRegionEntriesBase, 256, \ 164 "Max number of regions in a fine-grain table per MB.") \ 165 range(1, max_jint/wordSize) \ 166 \ 167 product(intx, G1RSetRegionEntries, 0, \ 168 "Max number of regions for which we keep bitmaps." \ 169 "Will be set ergonomically by default") \ 170 range(0, max_jint/wordSize) \ 171 constraint(G1RSetRegionEntriesConstraintFunc,AfterErgo) \ 172 \ 173 develop(intx, G1RSetSparseRegionEntriesBase, 4, \ 174 "Max number of entries per region in a sparse table " \ 175 "per MB.") \ 176 range(1, max_jint/wordSize) \ 177 \ 178 product(intx, G1RSetSparseRegionEntries, 0, \ 179 "Max number of entries per region in a sparse table." \ 180 "Will be set ergonomically by default.") \ 181 range(0, max_jint/wordSize) \ 182 constraint(G1RSetSparseRegionEntriesConstraintFunc,AfterErgo) \ 183 \ 184 develop(intx, G1MaxVerifyFailures, -1, \ 185 "The maximum number of verification failures to print. " \ 186 "-1 means print all.") \ 187 range(-1, max_jint) \ 188 \ 189 product(uintx, G1ReservePercent, 10, \ 190 "It determines the minimum reserve we should have in the heap " \ 191 "to minimize the probability of promotion failure.") \ 192 range(0, 50) \ 193 \ 194 product(size_t, G1HeapRegionSize, 0, \ 195 "Size of the G1 regions.") \ 196 range(0, 32*M) \ 197 constraint(G1HeapRegionSizeConstraintFunc,AfterMemoryInit) \ 198 \ 199 product(uint, G1ConcRefinementThreads, 0, \ 200 "The number of parallel rem set update threads. " \ 201 "Will be set ergonomically by default.") \ 202 range(0, (max_jint-1)/wordSize) \ 203 \ 204 develop(bool, G1VerifyCTCleanup, false, \ 205 "Verify card table cleanup.") \ 206 \ 207 product(size_t, G1RSetScanBlockSize, 64, \ 208 "Size of a work unit of cards claimed by a worker thread" \ 209 "during RSet scanning.") \ 210 range(1, max_uintx) \ 211 \ 212 develop(uintx, G1DummyRegionsPerGC, 0, \ 213 "The number of dummy regions G1 will allocate at the end of " \ 214 "each evacuation pause in order to artificially fill up the " \ 215 "heap and stress the marking implementation.") \ 216 \ 217 develop(bool, G1ExitOnExpansionFailure, false, \ 218 "Raise a fatal VM exit out of memory failure in the event " \ 219 " that heap expansion fails due to running out of swap.") \ 220 \ 221 experimental(uintx, G1MaxNewSizePercent, 60, \ 222 "Percentage (0-100) of the heap size to use as default " \ 223 " maximum young gen size.") \ 224 range(0, 100) \ 225 constraint(G1MaxNewSizePercentConstraintFunc,AfterErgo) \ 226 \ 227 experimental(uintx, G1NewSizePercent, 5, \ 228 "Percentage (0-100) of the heap size to use as default " \ 229 "minimum young gen size.") \ 230 range(0, 100) \ 231 constraint(G1NewSizePercentConstraintFunc,AfterErgo) \ 232 \ 233 experimental(uintx, G1MixedGCLiveThresholdPercent, 85, \ 234 "Threshold for regions to be considered for inclusion in the " \ 235 "collection set of mixed GCs. " \ 236 "Regions with live bytes exceeding this will not be collected.") \ 237 range(0, 100) \ 238 \ 239 product(uintx, G1HeapWastePercent, 5, \ 240 "Amount of space, expressed as a percentage of the heap size, " \ 241 "that G1 is willing not to collect to avoid expensive GCs.") \ 242 range(0, 100) \ 243 \ 244 product(uintx, G1MixedGCCountTarget, 8, \ 245 "The target number of mixed GCs after a marking cycle.") \ 246 range(0, max_uintx) \ 247 \ 248 experimental(bool, G1EagerReclaimHumongousObjects, true, \ 249 "Try to reclaim dead large objects at every young GC.") \ 250 \ 251 experimental(bool, G1EagerReclaimHumongousObjectsWithStaleRefs, true, \ 252 "Try to reclaim dead large objects that have a few stale " \ 253 "references at every young GC.") \ 254 \ 255 experimental(size_t, G1RebuildRemSetChunkSize, 256 * K, \ 256 "Chunk size used for rebuilding the remembered set.") \ 257 range(4 * K, 32 * M) \ 258 \ 259 experimental(uintx, G1OldCSetRegionThresholdPercent, 10, \ 260 "An upper bound for the number of old CSet regions expressed " \ 261 "as a percentage of the heap size.") \ 262 range(0, 100) \ 263 \ 264 notproduct(bool, G1EvacuationFailureALot, false, \ 265 "Force use of evacuation failure handling during certain " \ 266 "evacuation pauses") \ 267 \ 268 develop(uintx, G1EvacuationFailureALotCount, 1000, \ 269 "Number of successful evacuations between evacuation failures " \ 270 "occurring at object copying") \ 271 \ 272 develop(uintx, G1EvacuationFailureALotInterval, 5, \ 273 "Total collections between forced triggering of evacuation " \ 274 "failures") \ 275 \ 276 develop(bool, G1EvacuationFailureALotDuringConcMark, true, \ 277 "Force use of evacuation failure handling during evacuation " \ 278 "pauses when marking is in progress") \ 279 \ 280 develop(bool, G1EvacuationFailureALotDuringInitialMark, true, \ 281 "Force use of evacuation failure handling during initial mark " \ 282 "evacuation pauses") \ 283 \ 284 develop(bool, G1EvacuationFailureALotDuringYoungGC, true, \ 285 "Force use of evacuation failure handling during young " \ 286 "evacuation pauses") \ 287 \ 288 develop(bool, G1EvacuationFailureALotDuringMixedGC, true, \ 289 "Force use of evacuation failure handling during mixed " \ 290 "evacuation pauses") \ 291 \ 292 diagnostic(bool, G1VerifyRSetsDuringFullGC, false, \ 293 "If true, perform verification of each heap region's " \ 294 "remembered set when verifying the heap during a full GC.") \ 295 \ 296 diagnostic(bool, G1VerifyHeapRegionCodeRoots, false, \ 297 "Verify the code root lists attached to each heap region.") \ 298 \ 299 develop(bool, G1VerifyBitmaps, false, \ 300 "Verifies the consistency of the marking bitmaps") \ 301 \ 302 manageable(uintx, G1PeriodicGCInterval, 0, \ 303 "Number of milliseconds after a previous GC to wait before " \ 304 "triggering a periodic gc. A value of zero disables periodically "\ 305 "enforced gc cycles.") \ 306 \ 307 product(bool, G1PeriodicGCInvokesConcurrent, true, \ 308 "Determines the kind of periodic GC. Set to true to have G1 " \ 309 "perform a concurrent GC as periodic GC, otherwise use a STW " \ 310 "Full GC.") \ 311 \ 312 manageable(double, G1PeriodicGCSystemLoadThreshold, 0.0, \ 313 "Maximum recent system wide load as returned by the 1m value " \ 314 "of getloadavg() at which G1 triggers a periodic GC. A load " \ 315 "above this value cancels a given periodic GC. A value of zero " \ 316 "disables this check.") \ 317 range(0.0, (double)max_uintx) \ 318 \ 319 experimental(uintx, G1YoungExpansionBufferPercent, 10, \ 320 "When heterogenous heap is enabled by AllocateOldGenAt " \ 321 "option, after every GC, young gen is re-sized which " \ 322 "involves system calls to commit/uncommit memory. To " \ 323 "reduce these calls, we keep a buffer of extra regions to " \ 324 "absorb small changes in young gen length. This flag takes " \ 325 "the buffer size as an percentage of young gen length") \ 326 range(0, 100) \ 327 \ 328 diagnostic(bool, G1PrintNUMAIdOfHeapRegions, false, \ 329 "Print NUMA id of committed HeapRegion(s)") \ 330 \ 331 diagnostic(bool, G1VerifyNUMAIdOfHeapRegions, false, \ 332 "Verify NUMA id of committed HeapRegion(s) whether those " \ 333 "regions are still on the firstly checked node or not.") 334 335 336 #endif // SHARE_GC_G1_G1_GLOBALS_HPP