1 /* 2 * Copyright (c) 2001, 2020, 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 \ 48 product(bool, G1UseAdaptiveIHOP, true, \ 49 "Adaptively adjust the initiating heap occupancy from the " \ 50 "initial value of InitiatingHeapOccupancyPercent. The policy " \ 51 "attempts to start marking in time based on application " \ 52 "behavior.") \ 53 \ 54 experimental(size_t, G1AdaptiveIHOPNumInitialSamples, 3, \ 55 "How many completed time periods from initial mark to first " \ 56 "mixed gc are required to use the input values for prediction " \ 57 "of the optimal occupancy to start marking.") \ 58 range(1, max_intx) \ 59 \ 60 product(uintx, G1ConfidencePercent, 50, \ 61 "Confidence level for MMU/pause predictions") \ 62 range(0, 100) \ 63 \ 64 diagnostic(intx, G1SummarizeRSetStatsPeriod, 0, \ 65 "The period (in number of GCs) at which we will generate " \ 66 "update buffer processing info " \ 67 "(0 means do not periodically generate this info); " \ 68 "it also requires that logging is enabled on the trace" \ 69 "level for gc+remset") \ 70 range(0, max_intx) \ 71 \ 72 product(double, G1ConcMarkStepDurationMillis, 10.0, \ 73 "Target duration of individual concurrent marking steps " \ 74 "in milliseconds.") \ 75 range(1.0, DBL_MAX) \ 76 \ 77 product(uint, G1RefProcDrainInterval, 1000, \ 78 "The number of discovered reference objects to process before " \ 79 "draining concurrent marking work queues.") \ 80 range(1, INT_MAX) \ 81 \ 82 experimental(bool, G1UseReferencePrecleaning, true, \ 83 "Concurrently preclean java.lang.ref.references instances " \ 84 "before the Remark pause.") \ 85 \ 86 experimental(double, G1LastPLABAverageOccupancy, 50.0, \ 87 "The expected average occupancy of the last PLAB in " \ 88 "percent.") \ 89 range(0.001, 100.0) \ 90 \ 91 product(size_t, G1SATBBufferSize, 1*K, \ 92 "Number of entries in an SATB log buffer.") \ 93 range(1, max_uintx) \ 94 \ 95 develop(intx, G1SATBProcessCompletedThreshold, 20, \ 96 "Number of completed buffers that triggers log processing.") \ 97 range(0, max_jint) \ 98 \ 99 product(uintx, G1SATBBufferEnqueueingThresholdPercent, 60, \ 100 "Before enqueueing them, each mutator thread tries to do some " \ 101 "filtering on the SATB buffers it generates. If post-filtering " \ 102 "the percentage of retained entries is over this threshold " \ 103 "the buffer will be enqueued for processing. A value of 0 " \ 104 "specifies that mutator threads should not do such filtering.") \ 105 range(0, 100) \ 106 \ 107 experimental(intx, G1ExpandByPercentOfAvailable, 20, \ 108 "When expanding, % of uncommitted space to claim.") \ 109 range(0, 100) \ 110 \ 111 product(size_t, G1UpdateBufferSize, 256, \ 112 "Size of an update buffer") \ 113 range(1, NOT_LP64(32*M) LP64_ONLY(1*G)) \ 114 \ 115 product(size_t, G1ConcRefinementYellowZone, 0, \ 116 "Number of enqueued update buffers that will " \ 117 "trigger concurrent processing. Will be selected ergonomically " \ 118 "by default.") \ 119 range(0, max_intx) \ 120 \ 121 product(size_t, G1ConcRefinementRedZone, 0, \ 122 "Maximum number of enqueued update buffers before mutator " \ 123 "threads start processing new ones instead of enqueueing them. " \ 124 "Will be selected ergonomically by default.") \ 125 range(0, max_intx) \ 126 \ 127 product(size_t, G1ConcRefinementGreenZone, 0, \ 128 "The number of update buffers that are left in the queue by the " \ 129 "concurrent processing threads. Will be selected ergonomically " \ 130 "by default.") \ 131 range(0, max_intx) \ 132 \ 133 product(uintx, G1ConcRefinementServiceIntervalMillis, 300, \ 134 "The last concurrent refinement thread wakes up every " \ 135 "specified number of milliseconds to do miscellaneous work.") \ 136 range(0, max_jint) \ 137 \ 138 product(size_t, G1ConcRefinementThresholdStep, 2, \ 139 "Each time the rset update queue increases by this amount " \ 140 "activate the next refinement thread if available. " \ 141 "The actual step size will be selected ergonomically by " \ 142 "default, with this value used to determine a lower bound.") \ 143 range(1, SIZE_MAX) \ 144 \ 145 product(intx, G1RSetUpdatingPauseTimePercent, 10, \ 146 "A target percentage of time that is allowed to be spend on " \ 147 "process RS update buffers during the collection pause.") \ 148 range(0, 100) \ 149 \ 150 product(bool, G1UseAdaptiveConcRefinement, true, \ 151 "Select green, yellow and red zones adaptively to meet the " \ 152 "the pause requirements.") \ 153 \ 154 product(size_t, G1ConcRSLogCacheSize, 10, \ 155 "Log base 2 of the length of conc RS hot-card cache.") \ 156 range(0, 27) \ 157 \ 158 product(uintx, G1ConcRSHotCardLimit, 4, \ 159 "The threshold that defines (>=) a hot card.") \ 160 range(0, max_jubyte) \ 161 \ 162 develop(intx, G1RSetRegionEntriesBase, 256, \ 163 "Max number of regions in a fine-grain table per MB.") \ 164 range(1, max_jint/wordSize) \ 165 \ 166 product(intx, G1RSetRegionEntries, 0, \ 167 "Max number of regions for which we keep bitmaps." \ 168 "Will be set ergonomically by default") \ 169 range(0, max_jint/wordSize) \ 170 constraint(G1RSetRegionEntriesConstraintFunc,AfterErgo) \ 171 \ 172 develop(intx, G1RSetSparseRegionEntriesBase, 4, \ 173 "Max number of entries per region in a sparse table " \ 174 "per MB.") \ 175 range(1, max_jint/wordSize) \ 176 \ 177 product(intx, G1RSetSparseRegionEntries, 0, \ 178 "Max number of entries per region in a sparse table." \ 179 "Will be set ergonomically by default.") \ 180 range(0, max_jint/wordSize) \ 181 constraint(G1RSetSparseRegionEntriesConstraintFunc,AfterErgo) \ 182 \ 183 develop(intx, G1MaxVerifyFailures, -1, \ 184 "The maximum number of verification failures to print. " \ 185 "-1 means print all.") \ 186 range(-1, max_jint) \ 187 \ 188 product(uintx, G1ReservePercent, 10, \ 189 "It determines the minimum reserve we should have in the heap " \ 190 "to minimize the probability of promotion failure.") \ 191 range(0, 50) \ 192 \ 193 product(size_t, G1HeapRegionSize, 0, \ 194 "Size of the G1 regions.") \ 195 range(0, 32*M) \ 196 constraint(G1HeapRegionSizeConstraintFunc,AfterMemoryInit) \ 197 \ 198 product(uint, G1ConcRefinementThreads, 0, \ 199 "The number of parallel rem set update threads. " \ 200 "Will be set ergonomically by default.") \ 201 range(0, (max_jint-1)/wordSize) \ 202 \ 203 develop(bool, G1VerifyCTCleanup, false, \ 204 "Verify card table cleanup.") \ 205 \ 206 develop(uintx, G1DummyRegionsPerGC, 0, \ 207 "The number of dummy regions G1 will allocate at the end of " \ 208 "each evacuation pause in order to artificially fill up the " \ 209 "heap and stress the marking implementation.") \ 210 \ 211 develop(bool, G1ExitOnExpansionFailure, false, \ 212 "Raise a fatal VM exit out of memory failure in the event " \ 213 " that heap expansion fails due to running out of swap.") \ 214 \ 215 experimental(uintx, G1MaxNewSizePercent, 60, \ 216 "Percentage (0-100) of the heap size to use as default " \ 217 " maximum young gen size.") \ 218 range(0, 100) \ 219 constraint(G1MaxNewSizePercentConstraintFunc,AfterErgo) \ 220 \ 221 experimental(uintx, G1NewSizePercent, 5, \ 222 "Percentage (0-100) of the heap size to use as default " \ 223 "minimum young gen size.") \ 224 range(0, 100) \ 225 constraint(G1NewSizePercentConstraintFunc,AfterErgo) \ 226 \ 227 experimental(uintx, G1MixedGCLiveThresholdPercent, 85, \ 228 "Threshold for regions to be considered for inclusion in the " \ 229 "collection set of mixed GCs. " \ 230 "Regions with live bytes exceeding this will not be collected.") \ 231 range(0, 100) \ 232 \ 233 product(uintx, G1HeapWastePercent, 5, \ 234 "Amount of space, expressed as a percentage of the heap size, " \ 235 "that G1 is willing not to collect to avoid expensive GCs.") \ 236 range(0, 100) \ 237 \ 238 product(uintx, G1MixedGCCountTarget, 8, \ 239 "The target number of mixed GCs after a marking cycle.") \ 240 range(0, max_uintx) \ 241 \ 242 experimental(bool, G1EagerReclaimHumongousObjects, true, \ 243 "Try to reclaim dead large objects at every young GC.") \ 244 \ 245 experimental(bool, G1EagerReclaimHumongousObjectsWithStaleRefs, true, \ 246 "Try to reclaim dead large objects that have a few stale " \ 247 "references at every young GC.") \ 248 \ 249 experimental(size_t, G1RebuildRemSetChunkSize, 256 * K, \ 250 "Chunk size used for rebuilding the remembered set.") \ 251 range(4 * K, 32 * M) \ 252 \ 253 experimental(uintx, G1OldCSetRegionThresholdPercent, 10, \ 254 "An upper bound for the number of old CSet regions expressed " \ 255 "as a percentage of the heap size.") \ 256 range(0, 100) \ 257 \ 258 notproduct(bool, G1EvacuationFailureALot, false, \ 259 "Force use of evacuation failure handling during certain " \ 260 "evacuation pauses") \ 261 \ 262 develop(uintx, G1EvacuationFailureALotCount, 1000, \ 263 "Number of successful evacuations between evacuation failures " \ 264 "occurring at object copying") \ 265 \ 266 develop(uintx, G1EvacuationFailureALotInterval, 5, \ 267 "Total collections between forced triggering of evacuation " \ 268 "failures") \ 269 \ 270 develop(bool, G1EvacuationFailureALotDuringConcMark, true, \ 271 "Force use of evacuation failure handling during evacuation " \ 272 "pauses when marking is in progress") \ 273 \ 274 develop(bool, G1EvacuationFailureALotDuringInitialMark, true, \ 275 "Force use of evacuation failure handling during initial mark " \ 276 "evacuation pauses") \ 277 \ 278 develop(bool, G1EvacuationFailureALotDuringYoungGC, true, \ 279 "Force use of evacuation failure handling during young " \ 280 "evacuation pauses") \ 281 \ 282 develop(bool, G1EvacuationFailureALotDuringMixedGC, true, \ 283 "Force use of evacuation failure handling during mixed " \ 284 "evacuation pauses") \ 285 \ 286 diagnostic(bool, G1VerifyRSetsDuringFullGC, false, \ 287 "If true, perform verification of each heap region's " \ 288 "remembered set when verifying the heap during a full GC.") \ 289 \ 290 diagnostic(bool, G1VerifyHeapRegionCodeRoots, false, \ 291 "Verify the code root lists attached to each heap region.") \ 292 \ 293 develop(bool, G1VerifyBitmaps, false, \ 294 "Verifies the consistency of the marking bitmaps") \ 295 \ 296 manageable(uintx, G1PeriodicGCInterval, 0, \ 297 "Number of milliseconds after a previous GC to wait before " \ 298 "triggering a periodic gc. A value of zero disables periodically "\ 299 "enforced gc cycles.") \ 300 \ 301 product(bool, G1PeriodicGCInvokesConcurrent, true, \ 302 "Determines the kind of periodic GC. Set to true to have G1 " \ 303 "perform a concurrent GC as periodic GC, otherwise use a STW " \ 304 "Full GC.") \ 305 \ 306 manageable(double, G1PeriodicGCSystemLoadThreshold, 0.0, \ 307 "Maximum recent system wide load as returned by the 1m value " \ 308 "of getloadavg() at which G1 triggers a periodic GC. A load " \ 309 "above this value cancels a given periodic GC. A value of zero " \ 310 "disables this check.") \ 311 range(0.0, (double)max_uintx) \ 312 \ 313 experimental(uintx, G1YoungExpansionBufferPercent, 10, \ 314 "When heterogenous heap is enabled by AllocateOldGenAt " \ 315 "option, after every GC, young gen is re-sized which " \ 316 "involves system calls to commit/uncommit memory. To " \ 317 "reduce these calls, we keep a buffer of extra regions to " \ 318 "absorb small changes in young gen length. This flag takes " \ 319 "the buffer size as an percentage of young gen length") \ 320 range(0, 100) \ 321 322 323 #endif // SHARE_GC_G1_G1_GLOBALS_HPP