1 /*
2 * Copyright (c) 1997, 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_SHARED_GC_GLOBALS_HPP
26 #define SHARE_GC_SHARED_GC_GLOBALS_HPP
27
28 #include "runtime/globals_shared.hpp"
29 #include "utilities/macros.hpp"
30 #if INCLUDE_EPSILONGC
31 #include "gc/epsilon/epsilon_globals.hpp"
32 #endif
33 #if INCLUDE_G1GC
34 #include "gc/g1/g1_globals.hpp"
35 #endif
36 #if INCLUDE_PARALLELGC
37 #include "gc/parallel/parallel_globals.hpp"
38 #endif
39 #if INCLUDE_SERIALGC
40 #include "gc/serial/serial_globals.hpp"
41 #endif
42 #if INCLUDE_SHENANDOAHGC
43 #include "gc/shenandoah/shenandoah_globals.hpp"
44 #endif
45 #if INCLUDE_ZGC
46 #include "gc/z/z_globals.hpp"
47 #endif
48
49 #define GC_FLAGS(develop, \
50 develop_pd, \
51 product, \
52 product_pd, \
53 diagnostic, \
54 diagnostic_pd, \
55 experimental, \
56 notproduct, \
57 manageable, \
58 product_rw, \
59 lp64_product, \
60 range, \
61 constraint, \
62 writeable) \
63 \
64 EPSILONGC_ONLY(GC_EPSILON_FLAGS( \
65 develop, \
66 develop_pd, \
67 product, \
68 product_pd, \
69 diagnostic, \
70 diagnostic_pd, \
71 experimental, \
72 notproduct, \
73 manageable, \
74 product_rw, \
75 lp64_product, \
76 range, \
77 constraint, \
78 writeable)) \
79 \
80 G1GC_ONLY(GC_G1_FLAGS( \
81 develop, \
82 develop_pd, \
83 product, \
84 product_pd, \
85 diagnostic, \
86 diagnostic_pd, \
87 experimental, \
88 notproduct, \
89 manageable, \
90 product_rw, \
91 lp64_product, \
92 range, \
93 constraint, \
94 writeable)) \
95 \
96 PARALLELGC_ONLY(GC_PARALLEL_FLAGS( \
97 develop, \
98 develop_pd, \
99 product, \
100 product_pd, \
101 diagnostic, \
102 diagnostic_pd, \
103 experimental, \
104 notproduct, \
105 manageable, \
106 product_rw, \
107 lp64_product, \
108 range, \
109 constraint, \
110 writeable)) \
111 \
112 SERIALGC_ONLY(GC_SERIAL_FLAGS( \
113 develop, \
114 develop_pd, \
115 product, \
116 product_pd, \
117 diagnostic, \
118 diagnostic_pd, \
119 experimental, \
120 notproduct, \
121 manageable, \
122 product_rw, \
123 lp64_product, \
124 range, \
125 constraint, \
126 writeable)) \
127 \
128 SHENANDOAHGC_ONLY(GC_SHENANDOAH_FLAGS( \
129 develop, \
130 develop_pd, \
131 product, \
132 product_pd, \
133 diagnostic, \
134 diagnostic_pd, \
135 experimental, \
136 notproduct, \
137 manageable, \
138 product_rw, \
139 lp64_product, \
140 range, \
141 constraint, \
142 writeable)) \
143 \
144 ZGC_ONLY(GC_Z_FLAGS( \
145 develop, \
146 develop_pd, \
147 product, \
148 product_pd, \
149 diagnostic, \
150 diagnostic_pd, \
151 experimental, \
152 notproduct, \
153 manageable, \
154 product_rw, \
155 lp64_product, \
156 range, \
157 constraint, \
158 writeable)) \
159 \
160 /* gc */ \
161 \
162 product(bool, UseSerialGC, false, \
163 "Use the Serial garbage collector") \
164 \
165 product(bool, UseG1GC, false, \
166 "Use the Garbage-First garbage collector") \
167 \
168 product(bool, UseParallelGC, false, \
169 "Use the Parallel Scavenge garbage collector") \
170 \
171 product(bool, UseParallelOldGC, false, \
172 "Use the Parallel Old garbage collector") \
173 \
174 experimental(bool, UseEpsilonGC, false, \
175 "Use the Epsilon (no-op) garbage collector") \
176 \
177 experimental(bool, UseZGC, false, \
178 "Use the Z garbage collector") \
179 \
180 experimental(bool, UseShenandoahGC, false, \
181 "Use the Shenandoah garbage collector") \
182 \
183 product(uint, ParallelGCThreads, 0, \
184 "Number of parallel threads parallel gc will use") \
185 constraint(ParallelGCThreadsConstraintFunc,AfterErgo) \
186 \
187 diagnostic(bool, UseSemaphoreGCThreadsSynchronization, true, \
188 "Use semaphore synchronization for the GC Threads, " \
189 "instead of synchronization based on mutexes") \
190 \
191 product(bool, UseDynamicNumberOfGCThreads, true, \
192 "Dynamically choose the number of threads up to a maximum of " \
193 "ParallelGCThreads parallel collectors will use for garbage " \
194 "collection work") \
195 \
196 diagnostic(bool, InjectGCWorkerCreationFailure, false, \
197 "Inject thread creation failures for " \
198 "UseDynamicNumberOfGCThreads") \
199 \
200 diagnostic(bool, ForceDynamicNumberOfGCThreads, false, \
201 "Force dynamic selection of the number of " \
202 "parallel threads parallel gc will use to aid debugging") \
203 \
204 product(size_t, HeapSizePerGCThread, ScaleForWordSize(32*M), \
205 "Size of heap (bytes) per GC thread used in calculating the " \
206 "number of GC threads") \
207 range((size_t)os::vm_page_size(), (size_t)max_uintx) \
208 \
209 product(uint, ConcGCThreads, 0, \
210 "Number of threads concurrent gc will use") \
211 constraint(ConcGCThreadsConstraintFunc,AfterErgo) \
212 \
213 product(uint, GCTaskTimeStampEntries, 200, \
214 "Number of time stamp entries per gc worker thread") \
215 range(1, max_jint) \
216 \
217 product(bool, AlwaysTenure, false, \
218 "Always tenure objects in eden (ParallelGC only)") \
219 \
220 product(bool, NeverTenure, false, \
221 "Never tenure objects in eden, may tenure on overflow " \
222 "(ParallelGC only)") \
223 \
224 product(bool, ScavengeBeforeFullGC, true, \
225 "Scavenge youngest generation before each full GC.") \
226 \
227 product(bool, ExplicitGCInvokesConcurrent, false, \
228 "A System.gc() request invokes a concurrent collection; " \
229 "(effective only when using concurrent collectors)") \
230 \
231 product(uintx, GCLockerEdenExpansionPercent, 5, \
232 "How much the GC can expand the eden by while the GC locker " \
233 "is active (as a percentage)") \
234 range(0, 100) \
235 \
236 diagnostic(uintx, GCLockerRetryAllocationCount, 2, \
237 "Number of times to retry allocations when " \
238 "blocked by the GC locker") \
239 range(0, max_uintx) \
240 \
241 product(uintx, ParallelGCBufferWastePct, 10, \
242 "Wasted fraction of parallel allocation buffer") \
243 range(0, 100) \
244 \
245 product(uintx, TargetPLABWastePct, 10, \
246 "Target wasted space in last buffer as percent of overall " \
247 "allocation") \
248 range(1, 100) \
249 \
250 product(uintx, PLABWeight, 75, \
251 "Percentage (0-100) used to weight the current sample when " \
252 "computing exponentially decaying average for ResizePLAB") \
253 range(0, 100) \
254 \
255 product(bool, ResizePLAB, true, \
256 "Dynamically resize (survivor space) promotion LAB's") \
257 \
258 product(int, ParGCArrayScanChunk, 50, \
259 "Scan a subset of object array and push remainder, if array is " \
260 "bigger than this") \
261 range(1, max_jint/3) \
262 \
263 \
264 product(bool, AlwaysPreTouch, false, \
265 "Force all freshly committed pages to be pre-touched") \
266 \
267 product(size_t, PreTouchParallelChunkSize, 1 * G, \
268 "Per-thread chunk size for parallel memory pre-touch.") \
269 range(1, SIZE_MAX / 2) \
270 \
271 /* where does the range max value of (max_jint - 1) come from? */ \
272 product(size_t, MarkStackSizeMax, NOT_LP64(4*M) LP64_ONLY(512*M), \
273 "Maximum size of marking stack") \
274 range(1, (max_jint - 1)) \
275 \
276 product(size_t, MarkStackSize, NOT_LP64(32*K) LP64_ONLY(4*M), \
277 "Size of marking stack") \
278 constraint(MarkStackSizeConstraintFunc,AfterErgo) \
279 \
280 product(intx, RefDiscoveryPolicy, 0, \
281 "Select type of reference discovery policy: " \
282 "reference-based(0) or referent-based(1)") \
283 range(ReferenceProcessor::DiscoveryPolicyMin, \
284 ReferenceProcessor::DiscoveryPolicyMax) \
285 \
286 product(bool, ParallelRefProcEnabled, false, \
287 "Enable parallel reference processing whenever possible") \
288 \
289 product(bool, ParallelRefProcBalancingEnabled, true, \
290 "Enable balancing of reference processing queues") \
291 \
292 experimental(size_t, ReferencesPerThread, 1000, \
293 "Ergonomically start one thread for this amount of " \
294 "references for reference processing if " \
295 "ParallelRefProcEnabled is true. Specify 0 to disable and " \
296 "use all threads.") \
297 \
298 product(uintx, InitiatingHeapOccupancyPercent, 45, \
299 "The percent occupancy (IHOP) of the current old generation " \
300 "capacity above which a concurrent mark cycle will be initiated " \
301 "Its value may change over time if adaptive IHOP is enabled, " \
302 "otherwise the value remains constant. " \
303 "In the latter case a value of 0 will result as frequent as " \
304 "possible concurrent marking cycles. A value of 100 disables " \
305 "concurrent marking. " \
306 "Fragmentation waste in the old generation is not considered " \
307 "free space in this calculation. (G1 collector only)") \
308 range(0, 100) \
309 \
310 notproduct(bool, ScavengeALot, false, \
311 "Force scavenge at every Nth exit from the runtime system " \
312 "(N=ScavengeALotInterval)") \
313 \
314 develop(bool, FullGCALot, false, \
315 "Force full gc at every Nth exit from the runtime system " \
316 "(N=FullGCALotInterval)") \
317 \
318 notproduct(bool, GCALotAtAllSafepoints, false, \
319 "Enforce ScavengeALot/GCALot at all potential safepoints") \
320 \
321 notproduct(bool, PromotionFailureALot, false, \
322 "Use promotion failure handling on every youngest generation " \
323 "collection") \
324 \
325 develop(uintx, PromotionFailureALotCount, 1000, \
326 "Number of promotion failures occurring at PLAB promotion " \
327 "attempts at young collectors") \
328 \
329 develop(uintx, PromotionFailureALotInterval, 5, \
330 "Total collections between promotion failures a lot") \
331 \
332 diagnostic(bool, UseOWSTTaskTerminator, true, \
333 "Use Optimized Work Stealing Threads task termination " \
334 "protocol") \
335 \
336 experimental(uintx, WorkStealingSleepMillis, 1, \
337 "Sleep time when sleep is used for yields") \
338 \
339 experimental(uintx, WorkStealingYieldsBeforeSleep, 5000, \
340 "Number of yields before a sleep is done during work stealing") \
341 \
342 experimental(uintx, WorkStealingHardSpins, 4096, \
343 "Number of iterations in a spin loop between checks on " \
344 "time out of hard spin") \
345 \
346 experimental(uintx, WorkStealingSpinToYieldRatio, 10, \
347 "Ratio of hard spins to calls to yield") \
348 \
349 develop(uintx, ObjArrayMarkingStride, 2048, \
350 "Number of object array elements to push onto the marking stack " \
351 "before pushing a continuation entry") \
352 \
353 develop(bool, MetadataAllocationFailALot, false, \
354 "Fail metadata allocations at intervals controlled by " \
355 "MetadataAllocationFailALotInterval") \
356 \
357 develop(uintx, MetadataAllocationFailALotInterval, 1000, \
358 "Metadata allocation failure a lot interval") \
359 \
360 product(bool, ExecutingUnitTests, false, \
361 "Whether the JVM is running unit tests or not") \
362 \
363 product_pd(bool, UseTLAB, "Use thread-local object allocation") \
364 \
365 product_pd(bool, ResizeTLAB, \
366 "Dynamically resize TLAB size for threads") \
367 \
368 product(bool, ZeroTLAB, false, \
369 "Zero out the newly created TLAB") \
370 \
371 product(bool, TLABStats, true, \
372 "Provide more detailed and expensive TLAB statistics.") \
373 \
374 product_pd(bool, NeverActAsServerClassMachine, \
375 "Never act like a server-class machine") \
376 \
377 product(bool, AlwaysActAsServerClassMachine, false, \
378 "Always act like a server-class machine") \
379 \
380 product_pd(uint64_t, MaxRAM, \
381 "Real memory size (in bytes) used to set maximum heap size") \
382 range(0, 0XFFFFFFFFFFFFFFFF) \
383 \
384 product(bool, AggressiveHeap, false, \
385 "Optimize heap options for long-running memory intensive apps") \
386 \
387 product(size_t, ErgoHeapSizeLimit, 0, \
388 "Maximum ergonomically set heap size (in bytes); zero means use " \
389 "MaxRAM * MaxRAMPercentage / 100") \
390 range(0, max_uintx) \
391 \
392 product(uintx, MaxRAMFraction, 4, \
393 "Maximum fraction (1/n) of real memory used for maximum heap " \
394 "size. " \
395 "Deprecated, use MaxRAMPercentage instead") \
396 range(1, max_uintx) \
397 \
398 product(uintx, MinRAMFraction, 2, \
399 "Minimum fraction (1/n) of real memory used for maximum heap " \
400 "size on systems with small physical memory size. " \
401 "Deprecated, use MinRAMPercentage instead") \
402 range(1, max_uintx) \
403 \
404 product(uintx, InitialRAMFraction, 64, \
405 "Fraction (1/n) of real memory used for initial heap size. " \
406 "Deprecated, use InitialRAMPercentage instead") \
407 range(1, max_uintx) \
408 \
409 product(double, MaxRAMPercentage, 25.0, \
410 "Maximum percentage of real memory used for maximum heap size") \
411 range(0.0, 100.0) \
412 \
413 product(double, MinRAMPercentage, 50.0, \
414 "Minimum percentage of real memory used for maximum heap" \
415 "size on systems with small physical memory size") \
416 range(0.0, 100.0) \
417 \
418 product(double, InitialRAMPercentage, 1.5625, \
419 "Percentage of real memory used for initial heap size") \
420 range(0.0, 100.0) \
421 \
422 product(int, ActiveProcessorCount, -1, \
423 "Specify the CPU count the VM should use and report as active") \
424 \
425 develop(uintx, MaxVirtMemFraction, 2, \
426 "Maximum fraction (1/n) of virtual memory used for ergonomically "\
427 "determining maximum heap size") \
428 \
429 product(bool, UseAdaptiveSizePolicy, true, \
430 "Use adaptive generation sizing policies") \
431 \
432 product(bool, UsePSAdaptiveSurvivorSizePolicy, true, \
433 "Use adaptive survivor sizing policies") \
434 \
435 product(bool, UseAdaptiveGenerationSizePolicyAtMinorCollection, true, \
436 "Use adaptive young-old sizing policies at minor collections") \
437 \
438 product(bool, UseAdaptiveGenerationSizePolicyAtMajorCollection, true, \
439 "Use adaptive young-old sizing policies at major collections") \
440 \
441 product(bool, UseAdaptiveSizePolicyWithSystemGC, false, \
442 "Include statistics from System.gc() for adaptive size policy") \
443 \
444 product(bool, UseAdaptiveGCBoundary, false, \
445 "Allow young-old boundary to move") \
446 \
447 develop(intx, PSAdaptiveSizePolicyResizeVirtualSpaceAlot, -1, \
448 "Resize the virtual spaces of the young or old generations") \
449 range(-1, 1) \
450 \
451 product(uintx, AdaptiveSizeThroughPutPolicy, 0, \
452 "Policy for changing generation size for throughput goals") \
453 range(0, 1) \
454 \
455 product(uintx, AdaptiveSizePolicyInitializingSteps, 20, \
456 "Number of steps where heuristics is used before data is used") \
457 range(0, max_uintx) \
458 \
459 develop(uintx, AdaptiveSizePolicyReadyThreshold, 5, \
460 "Number of collections before the adaptive sizing is started") \
461 \
462 product(uintx, AdaptiveSizePolicyOutputInterval, 0, \
463 "Collection interval for printing information; zero means never") \
464 range(0, max_uintx) \
465 \
466 product(bool, UseAdaptiveSizePolicyFootprintGoal, true, \
467 "Use adaptive minimum footprint as a goal") \
468 \
469 product(uintx, AdaptiveSizePolicyWeight, 10, \
470 "Weight given to exponential resizing, between 0 and 100") \
471 range(0, 100) \
472 \
473 product(uintx, AdaptiveTimeWeight, 25, \
474 "Weight given to time in adaptive policy, between 0 and 100") \
475 range(0, 100) \
476 \
477 product(uintx, PausePadding, 1, \
478 "How much buffer to keep for pause time") \
479 range(0, max_juint) \
480 \
481 product(uintx, PromotedPadding, 3, \
482 "How much buffer to keep for promotion failure") \
483 range(0, max_juint) \
484 \
485 product(uintx, SurvivorPadding, 3, \
486 "How much buffer to keep for survivor overflow") \
487 range(0, max_juint) \
488 \
489 product(uintx, ThresholdTolerance, 10, \
490 "Allowed collection cost difference between generations") \
491 range(0, 100) \
492 \
493 product(uintx, AdaptiveSizePolicyCollectionCostMargin, 50, \
494 "If collection costs are within margin, reduce both by full " \
495 "delta") \
496 range(0, 100) \
497 \
498 product(uintx, YoungGenerationSizeIncrement, 20, \
499 "Adaptive size percentage change in young generation") \
500 range(0, 100) \
501 \
502 product(uintx, YoungGenerationSizeSupplement, 80, \
503 "Supplement to YoungedGenerationSizeIncrement used at startup") \
504 range(0, 100) \
505 \
506 product(uintx, YoungGenerationSizeSupplementDecay, 8, \
507 "Decay factor to YoungedGenerationSizeSupplement") \
508 range(1, max_uintx) \
509 \
510 product(uintx, TenuredGenerationSizeIncrement, 20, \
511 "Adaptive size percentage change in tenured generation") \
512 range(0, 100) \
513 \
514 product(uintx, TenuredGenerationSizeSupplement, 80, \
515 "Supplement to TenuredGenerationSizeIncrement used at startup") \
516 range(0, 100) \
517 \
518 product(uintx, TenuredGenerationSizeSupplementDecay, 2, \
519 "Decay factor to TenuredGenerationSizeIncrement") \
520 range(1, max_uintx) \
521 \
522 product(uintx, MaxGCPauseMillis, max_uintx - 1, \
523 "Adaptive size policy maximum GC pause time goal in millisecond, "\
524 "or (G1 Only) the maximum GC time per MMU time slice") \
525 range(1, max_uintx - 1) \
526 constraint(MaxGCPauseMillisConstraintFunc,AfterErgo) \
527 \
528 product(uintx, GCPauseIntervalMillis, 0, \
529 "Time slice for MMU specification") \
530 constraint(GCPauseIntervalMillisConstraintFunc,AfterErgo) \
531 \
532 product(uintx, MaxGCMinorPauseMillis, max_uintx, \
533 "Adaptive size policy maximum GC minor pause time goal " \
534 "in millisecond") \
535 range(0, max_uintx) \
536 \
537 product(uintx, GCTimeRatio, 99, \
538 "Adaptive size policy application time to GC time ratio") \
539 range(0, max_juint) \
540 \
541 product(uintx, AdaptiveSizeDecrementScaleFactor, 4, \
542 "Adaptive size scale down factor for shrinking") \
543 range(1, max_uintx) \
544 \
545 product(bool, UseAdaptiveSizeDecayMajorGCCost, true, \
546 "Adaptive size decays the major cost for long major intervals") \
547 \
548 product(uintx, AdaptiveSizeMajorGCDecayTimeScale, 10, \
549 "Time scale over which major costs decay") \
550 range(0, max_uintx) \
551 \
552 product(uintx, MinSurvivorRatio, 3, \
553 "Minimum ratio of young generation/survivor space size") \
554 range(3, max_uintx) \
555 \
556 product(uintx, InitialSurvivorRatio, 8, \
557 "Initial ratio of young generation/survivor space size") \
558 range(0, max_uintx) \
559 \
560 product(size_t, BaseFootPrintEstimate, 256*M, \
561 "Estimate of footprint other than Java Heap") \
562 range(0, max_uintx) \
563 \
564 product(bool, UseGCOverheadLimit, true, \
565 "Use policy to limit of proportion of time spent in GC " \
566 "before an OutOfMemory error is thrown") \
567 \
568 product(uintx, GCTimeLimit, 98, \
569 "Limit of the proportion of time spent in GC before " \
570 "an OutOfMemoryError is thrown (used with GCHeapFreeLimit)") \
571 range(0, 100) \
572 \
573 product(uintx, GCHeapFreeLimit, 2, \
574 "Minimum percentage of free space after a full GC before an " \
575 "OutOfMemoryError is thrown (used with GCTimeLimit)") \
576 range(0, 100) \
577 \
578 develop(uintx, GCOverheadLimitThreshold, 5, \
579 "Number of consecutive collections before gc time limit fires") \
580 range(1, max_uintx) \
581 \
582 product(intx, PrefetchCopyIntervalInBytes, -1, \
583 "How far ahead to prefetch destination area (<= 0 means off)") \
584 range(-1, max_jint) \
585 \
586 product(intx, PrefetchScanIntervalInBytes, -1, \
587 "How far ahead to prefetch scan area (<= 0 means off)") \
588 range(-1, max_jint) \
589 \
590 product(intx, PrefetchFieldsAhead, -1, \
591 "How many fields ahead to prefetch in oop scan (<= 0 means off)") \
592 range(-1, max_jint) \
593 \
594 diagnostic(bool, VerifyDuringStartup, false, \
595 "Verify memory system before executing any Java code " \
596 "during VM initialization") \
597 \
598 diagnostic(bool, VerifyBeforeExit, trueInDebug, \
599 "Verify system before exiting") \
600 \
601 diagnostic(bool, VerifyBeforeGC, false, \
602 "Verify memory system before GC") \
603 \
604 diagnostic(bool, VerifyAfterGC, false, \
605 "Verify memory system after GC") \
606 \
607 diagnostic(bool, VerifyDuringGC, false, \
608 "Verify memory system during GC (between phases)") \
609 \
610 diagnostic(ccstrlist, VerifyGCType, "", \
611 "GC type(s) to verify when Verify*GC is enabled." \
612 "Available types are collector specific.") \
613 \
614 diagnostic(ccstrlist, VerifySubSet, "", \
615 "Memory sub-systems to verify when Verify*GC flag(s) " \
616 "are enabled. One or more sub-systems can be specified " \
617 "in a comma separated string. Sub-systems are: " \
618 "threads, heap, symbol_table, string_table, codecache, " \
619 "dictionary, classloader_data_graph, metaspace, jni_handles, " \
620 "codecache_oops") \
621 \
622 diagnostic(bool, GCParallelVerificationEnabled, true, \
623 "Enable parallel memory system verification") \
624 \
625 diagnostic(bool, DeferInitialCardMark, false, \
626 "When +ReduceInitialCardMarks, explicitly defer any that " \
627 "may arise from new_pre_store_barrier") \
628 \
629 product(bool, UseCondCardMark, false, \
630 "Check for already marked card before updating card table") \
631 \
632 diagnostic(bool, VerifyRememberedSets, false, \
633 "Verify GC remembered sets") \
634 \
635 diagnostic(bool, VerifyObjectStartArray, true, \
636 "Verify GC object start array if verify before/after") \
637 \
638 product(bool, DisableExplicitGC, false, \
639 "Ignore calls to System.gc()") \
640 \
641 product(bool, PrintGC, false, \
642 "Print message at garbage collection. " \
643 "Deprecated, use -Xlog:gc instead.") \
644 \
645 product(bool, PrintGCDetails, false, \
646 "Print more details at garbage collection. " \
647 "Deprecated, use -Xlog:gc* instead.") \
648 \
649 develop(intx, ConcGCYieldTimeout, 0, \
650 "If non-zero, assert that GC threads yield within this " \
651 "number of milliseconds") \
652 range(0, max_intx) \
653 \
654 notproduct(intx, ScavengeALotInterval, 1, \
655 "Interval between which scavenge will occur with +ScavengeALot") \
656 \
657 notproduct(intx, FullGCALotInterval, 1, \
658 "Interval between which full gc will occur with +FullGCALot") \
659 \
660 notproduct(intx, FullGCALotStart, 0, \
661 "For which invocation to start FullGCAlot") \
662 \
663 notproduct(intx, FullGCALotDummies, 32*K, \
664 "Dummy object allocated with +FullGCALot, forcing all objects " \
665 "to move") \
666 \
667 /* gc parameters */ \
668 product(size_t, MinHeapSize, 0, \
669 "Minimum heap size (in bytes); zero means use ergonomics") \
670 constraint(MinHeapSizeConstraintFunc,AfterErgo) \
671 \
672 product(size_t, InitialHeapSize, 0, \
673 "Initial heap size (in bytes); zero means use ergonomics") \
674 constraint(InitialHeapSizeConstraintFunc,AfterErgo) \
675 \
676 product(size_t, MaxHeapSize, ScaleForWordSize(96*M), \
677 "Maximum heap size (in bytes)") \
678 constraint(MaxHeapSizeConstraintFunc,AfterErgo) \
679 \
680 manageable(size_t, SoftMaxHeapSize, 0, \
681 "Soft limit for maximum heap size (in bytes)") \
682 constraint(SoftMaxHeapSizeConstraintFunc,AfterMemoryInit) \
683 \
684 product(size_t, OldSize, ScaleForWordSize(4*M), \
685 "Initial tenured generation size (in bytes)") \
686 range(0, max_uintx) \
687 \
688 product(size_t, NewSize, ScaleForWordSize(1*M), \
689 "Initial new generation size (in bytes)") \
690 constraint(NewSizeConstraintFunc,AfterErgo) \
691 \
692 product(size_t, MaxNewSize, max_uintx, \
693 "Maximum new generation size (in bytes), max_uintx means set " \
694 "ergonomically") \
695 range(0, max_uintx) \
696 \
697 product_pd(size_t, HeapBaseMinAddress, \
698 "OS specific low limit for heap base address") \
699 constraint(HeapBaseMinAddressConstraintFunc,AfterErgo) \
700 \
701 product(size_t, PretenureSizeThreshold, 0, \
702 "Maximum size in bytes of objects allocated in DefNew " \
703 "generation; zero means no maximum") \
704 range(0, max_uintx) \
705 \
706 product(size_t, MinTLABSize, 2*K, \
707 "Minimum allowed TLAB size (in bytes)") \
708 range(1, max_uintx/2) \
709 constraint(MinTLABSizeConstraintFunc,AfterMemoryInit) \
710 \
711 product(size_t, TLABSize, 0, \
712 "Starting TLAB size (in bytes); zero means set ergonomically") \
713 constraint(TLABSizeConstraintFunc,AfterMemoryInit) \
714 \
715 product(size_t, YoungPLABSize, 4096, \
716 "Size of young gen promotion LAB's (in HeapWords)") \
717 constraint(YoungPLABSizeConstraintFunc,AfterMemoryInit) \
718 \
719 product(size_t, OldPLABSize, 1024, \
720 "Size of old gen promotion LAB's (in HeapWords)") \
721 constraint(OldPLABSizeConstraintFunc,AfterMemoryInit) \
722 \
723 product(uintx, TLABAllocationWeight, 35, \
724 "Allocation averaging weight") \
725 range(0, 100) \
726 \
727 /* Limit the lower bound of this flag to 1 as it is used */ \
728 /* in a division expression. */ \
729 product(uintx, TLABWasteTargetPercent, 1, \
730 "Percentage of Eden that can be wasted") \
731 range(1, 100) \
732 \
733 product(uintx, TLABRefillWasteFraction, 64, \
734 "Maximum TLAB waste at a refill (internal fragmentation)") \
735 range(1, max_juint) \
736 \
737 product(uintx, TLABWasteIncrement, 4, \
738 "Increment allowed waste at slow allocation") \
739 range(0, max_jint) \
740 constraint(TLABWasteIncrementConstraintFunc,AfterMemoryInit) \
741 \
742 product(uintx, SurvivorRatio, 8, \
743 "Ratio of eden/survivor space size") \
744 range(1, max_uintx-2) \
745 constraint(SurvivorRatioConstraintFunc,AfterMemoryInit) \
746 \
747 product(uintx, NewRatio, 2, \
748 "Ratio of old/new generation sizes") \
749 range(0, max_uintx-1) \
750 \
751 product_pd(size_t, NewSizeThreadIncrease, \
752 "Additional size added to desired new generation size per " \
753 "non-daemon thread (in bytes)") \
754 range(0, max_uintx) \
755 \
756 product(uintx, QueuedAllocationWarningCount, 0, \
757 "Number of times an allocation that queues behind a GC " \
758 "will retry before printing a warning") \
759 range(0, max_uintx) \
760 \
761 diagnostic(uintx, VerifyGCStartAt, 0, \
762 "GC invoke count where +VerifyBefore/AfterGC kicks in") \
763 range(0, max_uintx) \
764 \
765 diagnostic(intx, VerifyGCLevel, 0, \
766 "Generation level at which to start +VerifyBefore/AfterGC") \
767 range(0, 1) \
768 \
769 product(uintx, MaxTenuringThreshold, 15, \
770 "Maximum value for tenuring threshold") \
771 range(0, markWord::max_age + 1) \
772 constraint(MaxTenuringThresholdConstraintFunc,AfterErgo) \
773 \
774 product(uintx, InitialTenuringThreshold, 7, \
775 "Initial value for tenuring threshold") \
776 range(0, markWord::max_age + 1) \
777 constraint(InitialTenuringThresholdConstraintFunc,AfterErgo) \
778 \
779 product(uintx, TargetSurvivorRatio, 50, \
780 "Desired percentage of survivor space used after scavenge") \
781 range(0, 100) \
782 \
783 product(uintx, MarkSweepDeadRatio, 5, \
784 "Percentage (0-100) of the old gen allowed as dead wood. " \
785 "Serial mark sweep treats this as both the minimum and maximum " \
786 "value. " \
787 "Par compact uses a variable scale based on the density of the " \
788 "generation and treats this as the maximum value when the heap " \
789 "is either completely full or completely empty. Par compact " \
790 "also has a smaller default value; see arguments.cpp.") \
791 range(0, 100) \
792 \
793 product(uint, MarkSweepAlwaysCompactCount, 4, \
794 "How often should we fully compact the heap (ignoring the dead " \
795 "space parameters)") \
796 range(1, max_juint) \
797 \
798 develop(uintx, GCExpandToAllocateDelayMillis, 0, \
799 "Delay between expansion and allocation (in milliseconds)") \
800 \
801 product(uintx, GCDrainStackTargetSize, 64, \
802 "Number of entries we will try to leave on the stack " \
803 "during parallel gc") \
804 range(0, max_juint)
805
806 #endif // SHARE_GC_SHARED_GC_GLOBALS_HPP