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, 1 * M, \ 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(ccstr, ShenandoahGCHeuristics, "adaptive", \ 70 "The heuristics to use in Shenandoah GC. Possible values: " \ 71 "dynamic, adaptive, aggressive." \ 72 "Defaults to adaptive") \ 73 \ 74 product(uintx, ShenandoahRefProcFrequency, 5, \ 75 "How often should (weak, soft, etc) references be processed. " \ 76 "References get processed at every Nth GC cycle. " \ 77 "Set to 0 to disable reference processing. " \ 78 "Defaults to process references every 5 cycles.") \ 79 \ 80 product(uintx, ShenandoahUnloadClassesFrequency, 5, \ 81 "How often should classes get unloaded. " \ 82 "Class unloading is performed at every Nth GC cycle. " \ 83 "Set to 0 to disable concurrent class unloading. " \ 84 "Defaults to unload classes every 5 cycles.") \ 85 \ 86 experimental(uintx, ShenandoahFullGCThreshold, 3, \ 87 "How many cycles in a row to do degenerated marking on " \ 88 "cancelled GC before triggering a full-gc" \ 89 "Defaults to 3") \ 90 writeable(Always) \ 91 \ 92 product_rw(uintx, ShenandoahGarbageThreshold, 60, \ 93 "Sets the percentage of garbage a region need to contain before " \ 94 "it can be marked for collection. Applies to " \ 95 "Shenandoah GC dynamic Heuristic mode only (ignored otherwise). " \ 96 "Defaults to 60%.") \ 97 range(0,100) \ 98 \ 99 product_rw(uintx, ShenandoahFreeThreshold, 10, \ 100 "Set the percentage of free heap at which a GC cycle is started. " \ 101 "Applies to Shenandoah GC dynamic Heuristic mode only " \ 102 "(ignored otherwise). Defaults to 10%.") \ 103 range(0,100) \ 104 \ 105 product_rw(uintx, ShenandoahCSetThreshold, 40, \ 106 "Set the approximate target percentage of the heap for the" \ 107 "collection set. Defaults to 40%.") \ 108 range(0,100) \ 109 \ 110 product_rw(uintx, ShenandoahAllocationThreshold, 0, \ 111 "Set percentage of memory allocated since last GC cycle before " \ 112 "a new GC cycle is started. " \ 113 "Applies to Shenandoah GC dynamic Heuristic mode only " \ 114 "(ignored otherwise). Defauls to 0%.") \ 115 range(0,100) \ 116 \ 117 experimental(uintx, ShenandoahInitFreeThreshold, 10, \ 118 "Initial remaininig free threshold for adaptive heuristics") \ 119 range(0,100) \ 120 \ 121 experimental(uintx, ShenandoahMinFreeThreshold, 3, \ 122 "Minimum remaininig free threshold for adaptive heuristics") \ 123 range(0,100) \ 124 \ 125 experimental(uintx, ShenandoahMaxFreeThreshold, 70, \ 126 "Maximum remaininig free threshold for adaptive heuristics") \ 127 range(0,100) \ 128 \ 129 experimental(uintx, ShenandoahHappyCyclesThreshold, 5, \ 130 "How many successful marking cycles before improving free " \ 131 "threshold for adaptive heuristics") \ 132 \ 133 experimental(uint, ShenandoahMarkLoopStride, 1000, \ 134 "How many items are processed during one marking step") \ 135 \ 136 experimental(bool, ShenandoahConcurrentCodeRoots, true, \ 137 "Scan code roots concurrently, instead of during a pause") \ 138 \ 139 experimental(bool, ShenandoahNoBarriersForConst, true, \ 140 "Constant oops don't need barriers") \ 141 \ 142 experimental(bool, ShenandoahDontIncreaseWBFreq, true, \ 143 "Common 2 WriteBarriers or WriteBarrier and a ReadBarrier only " \ 144 "if the resulting WriteBarrier isn't executed more frequently") \ 145 \ 146 experimental(bool, ShenandoahNoLivenessFullGC, true, \ 147 "Skip liveness counting for mark during full GC.") \ 148 \ 149 experimental(bool, ShenandoahWriteBarrierToIR, true, \ 150 "Convert write barrier to IR instead of using assembly blob") \ 151 \ 152 experimental(bool, ShenandoahWriteBarrierCsetTestInIR, true, \ 153 "Perform cset test in IR rather than in the stub") \ 154 \ 155 experimental(bool, ShenandoahLoopOptsAfterExpansion, true, \ 156 "Attempt more loop opts after write barrier expansion") \ 157 \ 158 experimental(bool, UseShenandoahOWST, true, \ 159 "Use Shenandoah work stealing termination protocol") \ 160 \ 161 experimental(size_t, ShenandoahSATBBufferSize, 1 * K, \ 162 "Number of entries in an SATB log buffer.") \ 163 range(1, max_uintx) \ 164 \ 165 experimental(int, ShenandoahRegionSamplingRate, 40, \ 166 "Sampling rate for heap region sampling. " \ 167 "Number of milliseconds between samples") \ 168 writeable(Always) \ 169 \ 170 experimental(bool, ShenandoahRegionSampling, false, \ 171 "Turns on heap region sampling via JVMStat") \ 172 writeable(Always) \ 173 \ 174 experimental(bool, ShenandoahReduceStoreValBarrier, false, \ 175 "If true, only execute storeval barrier when updating " \ 176 "references.") \ 177 \ 178 diagnostic(bool, ShenandoahWriteBarrier, true, \ 179 "Turn on/off write barriers in Shenandoah") \ 180 \ 181 diagnostic(bool, ShenandoahReadBarrier, true, \ 182 "Turn on/off read barriers in Shenandoah") \ 183 \ 184 diagnostic(bool, ShenandoahCASBarrier, true, \ 185 "Turn on/off CAS barriers in Shenandoah") \ 186 \ 187 diagnostic(bool, ShenandoahAcmpBarrier, true, \ 188 "Turn on/off acmp barriers in Shenandoah") \ 189 \ 190 diagnostic(bool, ShenandoahCloneBarrier, true, \ 191 "Turn on/off clone barriers in Shenandoah") \ 192 \ 193 diagnostic(bool, ShenandoahStoreCheck, false, \ 194 "Emit additional code that checks objects are written to only" \ 195 " in to-space") \ 196 \ 197 develop(bool, ShenandoahDumpHeapBeforeConcurrentMark, false, \ 198 "Dump the ShenanodahHeap Before Each ConcurrentMark") \ 199 \ 200 develop(bool, ShenandoahDumpHeapAfterConcurrentMark, false, \ 201 "Dump the ShenanodahHeap After Each Concurrent Mark") \ 202 \ 203 develop(bool, ShenandoahVerifyWritesToFromSpace, false, \ 204 "Use Memory Protection to signal illegal writes to from space") \ 205 \ 206 develop(bool, ShenandoahVerifyReadsToFromSpace, false, \ 207 "Use Memory Protection to signal illegal reads to from space") \ 208 \ 209 develop(bool, ShenandoahVerify, false, \ 210 "Verify the Shenandoah garbage collector") \ 211 \ 212 develop(bool, VerifyStrictOopOperations, false, \ 213 "Verify that == and != are not used on oops. Only in fastdebug") \ 214 \ 215 develop(bool, ShenandoahVerifyOptoBarriers, false, \ 216 "Verify no missing barriers in c2") \ 217 \ 218 product(bool, ShenandoahAlwaysPreTouch, false, \ 219 "Pre-touch heap memory, overrides global AlwaysPreTouch") \ 220 \ 221 experimental(intx, ShenandoahMarkScanPrefetch, 32, \ 222 "How many objects to prefetch ahead when traversing mark bitmaps." \ 223 "Set to 0 to disable prefetching.") \ 224 range(0, 1024) \ 225 \ 226 experimental(intx, ShenandoahFullGCTries, 3, \ 227 "How many times to try to do Full GC on allocation failure." \ 228 "Set to 0 to never try, and fail instead.") \ 229 range(0, 16) \ 230 231 232 SHENANDOAH_FLAGS(DECLARE_DEVELOPER_FLAG, \ 233 DECLARE_PD_DEVELOPER_FLAG, \ 234 DECLARE_PRODUCT_FLAG, \ 235 DECLARE_PD_PRODUCT_FLAG, \ 236 DECLARE_DIAGNOSTIC_FLAG, \ 237 DECLARE_EXPERIMENTAL_FLAG, \ 238 DECLARE_NOTPRODUCT_FLAG, \ 239 DECLARE_MANAGEABLE_FLAG, \ 240 DECLARE_PRODUCT_RW_FLAG, \ 241 IGNORE_RANGE, \ 242 IGNORE_CONSTRAINT, \ 243 IGNORE_WRITEABLE) 244 245 #endif // SHARE_VM_GC_SHENANDOAH_SHENANDOAH_GLOBALS_HPP