1 /* 2 * Copyright (c) 2016, Red Hat, Inc. and/or its affiliates. 3 * 4 * This code is free software; you can redistribute it and/or modify it 5 * under the terms of the GNU General Public License version 2 only, as 6 * published by the Free Software Foundation. 7 * 8 * This code is distributed in the hope that it will be useful, but WITHOUT 9 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 10 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 11 * version 2 for more details (a copy is included in the LICENSE file that 12 * accompanied this code). 13 * 14 * You should have received a copy of the GNU General Public License version 15 * 2 along with this work; if not, write to the Free Software Foundation, 16 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. 17 * 18 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA 19 * or visit www.oracle.com if you need additional information or have any 20 * questions. 21 * 22 */ 23 24 #ifndef SHARE_VM_GC_SHENANDOAH_SHENANDOAH_GLOBALS_HPP 25 #define SHARE_VM_GC_SHENANDOAH_SHENANDOAH_GLOBALS_HPP 26 27 #include "runtime/globals.hpp" 28 29 #define SHENANDOAH_FLAGS(develop, \ 30 develop_pd, \ 31 product, \ 32 product_pd, \ 33 diagnostic, \ 34 experimental, \ 35 notproduct, \ 36 manageable, \ 37 product_rw, \ 38 range, \ 39 constraint, \ 40 writeable) \ 41 \ 42 product(bool, UseShenandoahGC, false, \ 43 "Use the Shenandoah garbage collector") \ 44 \ 45 product(bool, ShenandoahOptimizeFinals, true, \ 46 "Optimize barriers on final and stable fields/arrays. " \ 47 "Turn it off for maximum compatibility with reflection or JNI " \ 48 "code that manipulates final fields." \ 49 "Defaults to true. ") \ 50 \ 51 product(size_t, ShenandoahHeapRegionSize, 0, \ 52 "Size of the Shenandoah regions. " \ 53 "Determined automatically by default.") \ 54 \ 55 experimental(size_t, ShenandoahMinRegionSize, 256 * K, \ 56 "Minimum heap region size. ") \ 57 \ 58 experimental(size_t, ShenandoahMaxRegionSize, 32 * M, \ 59 "Maximum heap region size. ") \ 60 \ 61 experimental(size_t, ShenandoahTargetNumRegions, 2048, \ 62 "Target number of regions. We try to get around that many " \ 63 "regions, based on ShenandoahMinRegionSize and " \ 64 "ShenandoahMaxRegionSizeSize. ") \ 65 \ 66 product(bool, UseShenandoahMatrix, false, \ 67 "Keep a connection matrix and use this to drive collection sets") \ 68 \ 69 product(bool, PrintShenandoahMatrix, false, \ 70 "Print connection matrix after marking") \ 71 \ 72 product(bool, VerifyShenandoahMatrix, false, \ 73 "Verify connection matrix after marking") \ 74 \ 75 product(ccstr, ShenandoahGCHeuristics, "adaptive", \ 76 "The heuristics to use in Shenandoah GC. Possible values: " \ 77 "adaptive (adapt to maintain the given amount of free memory), " \ 78 "dynamic (start concurrent GC based on amount of free memory, " \ 79 "allocation threshold, etc), " \ 80 "passive (do not start concurrent GC, wait for Full GC) " \ 81 "aggressive (run concurrent GC continuously, evacuate everything), " \ 82 "partial (run partial collections along with concurrent GC). " \ 83 "Defaults to adaptive") \ 84 \ 85 experimental(ccstr, ShenandoahUpdateRefsEarly, "adaptive", \ 86 "Run a separate concurrent reference updating phase after" \ 87 "concurrent evacuation. Possible values: 'on', 'off', 'adaptive'")\ 88 \ 89 product(uintx, ShenandoahRefProcFrequency, 5, \ 90 "How often should (weak, soft, etc) references be processed. " \ 91 "References get processed at every Nth GC cycle. " \ 92 "Set to 0 to disable reference processing. " \ 93 "Defaults to process references every 5 cycles.") \ 94 \ 95 product(uintx, ShenandoahUnloadClassesFrequency, 5, \ 96 "How often should classes get unloaded. " \ 97 "Class unloading is performed at every Nth GC cycle. " \ 98 "Set to 0 to disable concurrent class unloading. " \ 99 "Defaults to unload classes every 5 cycles.") \ 100 \ 101 experimental(uintx, ShenandoahFullGCThreshold, 3, \ 102 "How many cycles in a row to do degenerated marking on " \ 103 "cancelled GC before triggering a full-gc" \ 104 "Defaults to 3") \ 105 writeable(Always) \ 106 \ 107 product_rw(uintx, ShenandoahGarbageThreshold, 60, \ 108 "Sets the percentage of garbage a region need to contain before " \ 109 "it can be marked for collection. Applies to " \ 110 "Shenandoah GC dynamic Heuristic mode only (ignored otherwise). " \ 111 "Defaults to 60%.") \ 112 range(0,100) \ 113 \ 114 product_rw(uintx, ShenandoahFreeThreshold, 10, \ 115 "Set the percentage of free heap at which a GC cycle is started. " \ 116 "Applies to Shenandoah GC dynamic Heuristic mode only " \ 117 "(ignored otherwise). Defaults to 10%.") \ 118 range(0,100) \ 119 \ 120 product_rw(uintx, ShenandoahCSetThreshold, 40, \ 121 "Set the approximate target percentage of the heap for the" \ 122 "collection set. Defaults to 40%.") \ 123 range(0,100) \ 124 \ 125 product_rw(uintx, ShenandoahAllocationThreshold, 0, \ 126 "Set percentage of memory allocated since last GC cycle before " \ 127 "a new GC cycle is started. " \ 128 "Applies to Shenandoah GC dynamic Heuristic mode only " \ 129 "(ignored otherwise). Defauls to 0%.") \ 130 range(0,100) \ 131 \ 132 experimental(uintx, ShenandoahMergeUpdateRefsMinGap, 100, \ 133 "If GC is currently running in separate update-refs mode " \ 134 "this numbers gives the threshold when to switch to " \ 135 "merged update-refs mode. Number is percentage relative to" \ 136 "duration(marking)+duration(update-refs).") \ 137 writeable(Always) \ 138 \ 139 experimental(uintx, ShenandoahMergeUpdateRefsMaxGap, 200, \ 140 "If GC is currently running in merged update-refs mode " \ 141 "this numbers gives the threshold when to switch to " \ 142 "separate update-refs mode. Number is percentage relative " \ 143 "to duration(marking)+duration(update-refs).") \ 144 writeable(Always) \ 145 \ 146 experimental(double, ShenandoahGCWorkerPerJavaThread, 0.5, \ 147 "Set GC worker to Java thread ratio when " \ 148 "UseDynamicNumberOfGCThreads is enabled") \ 149 range(0.1,10.0) \ 150 \ 151 experimental(uintx, ShenandoahInitFreeThreshold, 30, \ 152 "Initial remaining free threshold for adaptive heuristics") \ 153 range(0,100) \ 154 \ 155 experimental(uintx, ShenandoahMinFreeThreshold, 3, \ 156 "Minimum remaining free threshold for adaptive heuristics") \ 157 range(0,100) \ 158 \ 159 experimental(uintx, ShenandoahMaxFreeThreshold, 70, \ 160 "Maximum remaining free threshold for adaptive heuristics") \ 161 range(0,100) \ 162 \ 163 experimental(uintx, ShenandoahHappyCyclesThreshold, 3, \ 164 "How many successful marking cycles before improving free " \ 165 "threshold for adaptive heuristics") \ 166 \ 167 experimental(uintx, ShenandoahPartialInboundThreshold, 10, \ 168 "Specifies how many inbound regions a region can have maximum " \ 169 "to be considered for collection set in partial collections.") \ 170 writeable(Always) \ 171 \ 172 experimental(uint, ShenandoahMarkLoopStride, 1000, \ 173 "How many items are processed during one marking step") \ 174 \ 175 experimental(bool, ShenandoahConcurrentCodeRoots, true, \ 176 "Scan code roots concurrently, instead of during a pause") \ 177 \ 178 experimental(bool, ShenandoahNoBarriersForConst, true, \ 179 "Constant oops don't need barriers") \ 180 \ 181 experimental(bool, ShenandoahDontIncreaseWBFreq, true, \ 182 "Common 2 WriteBarriers or WriteBarrier and a ReadBarrier only " \ 183 "if the resulting WriteBarrier isn't executed more frequently") \ 184 \ 185 experimental(bool, ShenandoahNoLivenessFullGC, true, \ 186 "Skip liveness counting for mark during full GC.") \ 187 \ 188 experimental(bool, ShenandoahWriteBarrierToIR, true, \ 189 "Convert write barrier to IR instead of using assembly blob") \ 190 \ 191 experimental(bool, ShenandoahWriteBarrierCsetTestInIR, true, \ 192 "Perform cset test in IR rather than in the stub") \ 193 \ 194 experimental(bool, ShenandoahLoopOptsAfterExpansion, true, \ 195 "Attempt more loop opts after write barrier expansion") \ 196 \ 197 experimental(bool, UseShenandoahOWST, true, \ 198 "Use Shenandoah work stealing termination protocol") \ 199 \ 200 experimental(size_t, ShenandoahSATBBufferSize, 1 * K, \ 201 "Number of entries in an SATB log buffer.") \ 202 range(1, max_uintx) \ 203 \ 204 experimental(int, ShenandoahRegionSamplingRate, 40, \ 205 "Sampling rate for heap region sampling. " \ 206 "Number of milliseconds between samples") \ 207 writeable(Always) \ 208 \ 209 experimental(bool, ShenandoahRegionSampling, false, \ 210 "Turns on heap region sampling via JVMStat") \ 211 writeable(Always) \ 212 \ 213 experimental(bool, ShenandoahReduceStoreValBarrier, false, \ 214 "If true, only execute storeval barrier when updating " \ 215 "references.") \ 216 \ 217 experimental(bool, ShenandoahFastSyncRoots, true, \ 218 "Enable fast synchronizer roots scanning") \ 219 \ 220 diagnostic(bool, ShenandoahSATBBarrier, true, \ 221 "Turn on/off SATB barriers in Shenandoah") \ 222 \ 223 diagnostic(bool, ShenandoahWriteBarrier, true, \ 224 "Turn on/off write barriers in Shenandoah") \ 225 \ 226 diagnostic(bool, ShenandoahReadBarrier, true, \ 227 "Turn on/off read barriers in Shenandoah") \ 228 \ 229 diagnostic(bool, ShenandoahCASBarrier, true, \ 230 "Turn on/off CAS barriers in Shenandoah") \ 231 \ 232 diagnostic(bool, ShenandoahAcmpBarrier, true, \ 233 "Turn on/off acmp barriers in Shenandoah") \ 234 \ 235 diagnostic(bool, ShenandoahCloneBarrier, true, \ 236 "Turn on/off clone barriers in Shenandoah") \ 237 \ 238 diagnostic(bool, ShenandoahStoreCheck, false, \ 239 "Emit additional code that checks objects are written to only" \ 240 " in to-space") \ 241 \ 242 develop(bool, ShenandoahVerify, false, \ 243 "Verify the Shenandoah garbage collector") \ 244 \ 245 develop(bool, VerifyStrictOopOperations, false, \ 246 "Verify that == and != are not used on oops. Only in fastdebug") \ 247 \ 248 develop(bool, ShenandoahVerifyOptoBarriers, false, \ 249 "Verify no missing barriers in c2") \ 250 \ 251 product(bool, ShenandoahAlwaysPreTouch, false, \ 252 "Pre-touch heap memory, overrides global AlwaysPreTouch") \ 253 \ 254 experimental(intx, ShenandoahMarkScanPrefetch, 32, \ 255 "How many objects to prefetch ahead when traversing mark bitmaps." \ 256 "Set to 0 to disable prefetching.") \ 257 range(0, 256) \ 258 \ 259 experimental(intx, ShenandoahFullGCTries, 3, \ 260 "How many times to try to do Full GC on allocation failure." \ 261 "Set to 0 to never try, and fail instead.") \ 262 range(0, 16) \ 263 264 265 SHENANDOAH_FLAGS(DECLARE_DEVELOPER_FLAG, \ 266 DECLARE_PD_DEVELOPER_FLAG, \ 267 DECLARE_PRODUCT_FLAG, \ 268 DECLARE_PD_PRODUCT_FLAG, \ 269 DECLARE_DIAGNOSTIC_FLAG, \ 270 DECLARE_EXPERIMENTAL_FLAG, \ 271 DECLARE_NOTPRODUCT_FLAG, \ 272 DECLARE_MANAGEABLE_FLAG, \ 273 DECLARE_PRODUCT_RW_FLAG, \ 274 IGNORE_RANGE, \ 275 IGNORE_CONSTRAINT, \ 276 IGNORE_WRITEABLE) 277 278 #endif // SHARE_VM_GC_SHENANDOAH_SHENANDOAH_GLOBALS_HPP