1 /*
2 * Copyright (c) 1997, 2023, 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/shared/z_shared_globals.hpp"
47 #endif
48
49 #define GC_FLAGS(develop, \
50 develop_pd, \
51 product, \
52 product_pd, \
53 notproduct, \
54 range, \
55 constraint) \
56 \
57 EPSILONGC_ONLY(GC_EPSILON_FLAGS( \
58 develop, \
59 develop_pd, \
60 product, \
61 product_pd, \
62 notproduct, \
63 range, \
64 constraint)) \
65 \
66 G1GC_ONLY(GC_G1_FLAGS( \
67 develop, \
68 develop_pd, \
69 product, \
70 product_pd, \
71 notproduct, \
72 range, \
73 constraint)) \
74 \
75 PARALLELGC_ONLY(GC_PARALLEL_FLAGS( \
76 develop, \
77 develop_pd, \
78 product, \
79 product_pd, \
80 notproduct, \
81 range, \
82 constraint)) \
83 \
84 SERIALGC_ONLY(GC_SERIAL_FLAGS( \
85 develop, \
86 develop_pd, \
87 product, \
88 product_pd, \
89 notproduct, \
90 range, \
91 constraint)) \
92 \
93 SHENANDOAHGC_ONLY(GC_SHENANDOAH_FLAGS( \
94 develop, \
95 develop_pd, \
96 product, \
97 product_pd, \
98 notproduct, \
99 range, \
100 constraint)) \
101 \
102 ZGC_ONLY(GC_Z_SHARED_FLAGS( \
103 develop, \
104 develop_pd, \
105 product, \
106 product_pd, \
107 notproduct, \
108 range, \
109 constraint)) \
110 \
111 /* gc */ \
112 \
113 product(bool, UseSerialGC, false, \
114 "Use the Serial garbage collector") \
115 \
116 product(bool, UseG1GC, false, \
117 "Use the Garbage-First garbage collector") \
118 \
119 product(bool, UseParallelGC, false, \
120 "Use the Parallel garbage collector.") \
121 \
122 product(bool, UseEpsilonGC, false, EXPERIMENTAL, \
123 "Use the Epsilon (no-op) garbage collector") \
124 \
125 product(bool, UseZGC, false, \
126 "Use the Z garbage collector") \
127 \
128 product(bool, ZGenerational, false, \
129 "Use the generational version of ZGC") \
130 \
131 product(bool, UseShenandoahGC, false, \
132 "Use the Shenandoah garbage collector") \
133 \
134 /* notice: the max range value here is INT_MAX not UINT_MAX */ \
135 /* to protect from overflows */ \
136 product(uint, ParallelGCThreads, 0, \
137 "Number of parallel threads parallel gc will use") \
138 range(0, INT_MAX) \
139 \
140 product(bool, UseDynamicNumberOfGCThreads, true, \
141 "Dynamically choose the number of threads up to a maximum of " \
142 "ParallelGCThreads parallel collectors will use for garbage " \
143 "collection work") \
144 \
145 product(bool, InjectGCWorkerCreationFailure, false, DIAGNOSTIC, \
146 "Inject thread creation failures for " \
147 "UseDynamicNumberOfGCThreads") \
148 \
149 product(size_t, HeapSizePerGCThread, ScaleForWordSize(32*M), \
150 "Size of heap (bytes) per GC thread used in calculating the " \
151 "number of GC threads") \
152 constraint(VMPageSizeConstraintFunc, AtParse) \
153 \
154 product(uint, ConcGCThreads, 0, \
155 "Number of threads concurrent gc will use") \
156 \
157 product(bool, AlwaysTenure, false, \
158 "Always tenure objects in eden (ParallelGC only)") \
159 \
160 product(bool, NeverTenure, false, \
161 "Never tenure objects in eden, may tenure on overflow " \
162 "(ParallelGC only)") \
163 \
164 product(bool, ScavengeBeforeFullGC, true, \
165 "Scavenge youngest generation before each full GC.") \
166 \
167 product(bool, ExplicitGCInvokesConcurrent, false, \
168 "A System.gc() request invokes a concurrent collection; " \
169 "(effective only when using concurrent collectors)") \
170 \
171 product(uint, GCLockerEdenExpansionPercent, 5, \
172 "How much the GC can expand the eden by while the GC locker " \
173 "is active (as a percentage)") \
174 range(0, 100) \
175 \
176 product(uintx, GCLockerRetryAllocationCount, 2, DIAGNOSTIC, \
177 "Number of times to retry allocations when " \
178 "blocked by the GC locker") \
179 range(0, max_uintx) \
180 \
181 product(uint, ParallelGCBufferWastePct, 10, \
182 "Wasted fraction of parallel allocation buffer") \
183 range(0, 100) \
184 \
185 product(uint, TargetPLABWastePct, 10, \
186 "Target wasted space in last buffer as percent of overall " \
187 "allocation") \
188 range(1, 100) \
189 \
190 product(uint, PLABWeight, 75, \
191 "Percentage (0-100) used to weight the current sample when " \
192 "computing exponentially decaying average for ResizePLAB") \
193 range(0, 100) \
194 \
195 product(bool, ResizePLAB, true, \
196 "Dynamically resize (survivor space) promotion LAB's") \
197 \
198 product(int, ParGCArrayScanChunk, 50, \
199 "Scan a subset of object array and push remainder, if array is " \
200 "bigger than this") \
201 range(1, INT_MAX/3) \
202 \
203 \
204 product(bool, AlwaysPreTouch, false, \
205 "Force all freshly committed pages to be pre-touched") \
206 \
207 product(bool, AlwaysPreTouchStacks, false, DIAGNOSTIC, \
208 "Force java thread stacks to be fully pre-touched") \
209 \
210 product_pd(size_t, PreTouchParallelChunkSize, \
211 "Per-thread chunk size for parallel memory pre-touch.") \
212 range(4*K, SIZE_MAX / 2) \
213 \
214 /* where does the range max value of (max_jint - 1) come from? */ \
215 product(size_t, MarkStackSizeMax, NOT_LP64(4*M) LP64_ONLY(512*M), \
216 "Maximum size of marking stack") \
217 range(1, (INT_MAX - 1)) \
218 \
219 product(size_t, MarkStackSize, NOT_LP64(64*K) LP64_ONLY(4*M), \
220 "Size of marking stack") \
221 constraint(MarkStackSizeConstraintFunc,AfterErgo) \
222 range(1, (INT_MAX - 1)) \
223 \
224 product(bool, ParallelRefProcEnabled, false, \
225 "Enable parallel reference processing whenever possible") \
226 \
227 product(bool, ParallelRefProcBalancingEnabled, true, \
228 "Enable balancing of reference processing queues") \
229 \
230 product(size_t, ReferencesPerThread, 1000, EXPERIMENTAL, \
231 "Ergonomically start one thread for this amount of " \
232 "references for reference processing if " \
233 "ParallelRefProcEnabled is true. Specify 0 to disable and " \
234 "use all threads.") \
235 \
236 product(uint, InitiatingHeapOccupancyPercent, 45, \
237 "The percent occupancy (IHOP) of the current old generation " \
238 "capacity above which a concurrent mark cycle will be initiated " \
239 "Its value may change over time if adaptive IHOP is enabled, " \
240 "otherwise the value remains constant. " \
241 "In the latter case a value of 0 will result as frequent as " \
242 "possible concurrent marking cycles. A value of 100 disables " \
243 "concurrent marking. " \
244 "Fragmentation waste in the old generation is not considered " \
245 "free space in this calculation. (G1 collector only)") \
246 range(0, 100) \
247 \
248 notproduct(bool, ScavengeALot, false, \
249 "Force scavenge at every Nth exit from the runtime system " \
250 "(N=ScavengeALotInterval)") \
251 \
252 develop(bool, FullGCALot, false, \
253 "Force full gc at every Nth exit from the runtime system " \
254 "(N=FullGCALotInterval)") \
255 \
256 notproduct(bool, GCALotAtAllSafepoints, false, \
257 "Enforce ScavengeALot/GCALot at all potential safepoints") \
258 \
259 notproduct(bool, PromotionFailureALot, false, \
260 "Use promotion failure handling on every youngest generation " \
261 "collection") \
262 \
263 develop(uintx, PromotionFailureALotCount, 1000, \
264 "Number of promotion failures occurring at PLAB promotion " \
265 "attempts at young collectors") \
266 \
267 develop(uintx, PromotionFailureALotInterval, 5, \
268 "Total collections between promotion failures a lot") \
269 \
270 product(uintx, WorkStealingSleepMillis, 1, EXPERIMENTAL, \
271 "Sleep time when sleep is used for yields") \
272 \
273 product(uintx, WorkStealingYieldsBeforeSleep, 5000, EXPERIMENTAL, \
274 "Number of yields before a sleep is done during work stealing") \
275 \
276 product(uintx, WorkStealingHardSpins, 4096, EXPERIMENTAL, \
277 "Number of iterations in a spin loop between checks on " \
278 "time out of hard spin") \
279 \
280 product(uintx, WorkStealingSpinToYieldRatio, 10, EXPERIMENTAL, \
281 "Ratio of hard spins to calls to yield") \
282 \
283 develop(uintx, ObjArrayMarkingStride, 2048, \
284 "Number of object array elements to push onto the marking stack " \
285 "before pushing a continuation entry") \
286 \
287 develop(bool, MetadataAllocationFailALot, false, \
288 "Fail metadata allocations at intervals controlled by " \
289 "MetadataAllocationFailALotInterval") \
290 \
291 develop(uintx, MetadataAllocationFailALotInterval, 1000, \
292 "Metadata allocation failure a lot interval") \
293 \
294 product_pd(bool, NeverActAsServerClassMachine, \
295 "Never act like a server-class machine") \
296 \
297 product(bool, AlwaysActAsServerClassMachine, false, \
298 "Always act like a server-class machine") \
299 \
300 product_pd(uint64_t, MaxRAM, \
301 "Real memory size (in bytes) used to set maximum heap size") \
302 range(0, 0XFFFFFFFFFFFFFFFF) \
303 \
304 product(bool, AggressiveHeap, false, \
305 "Optimize heap options for long-running memory intensive apps") \
306 \
307 product(size_t, ErgoHeapSizeLimit, 0, \
308 "Maximum ergonomically set heap size (in bytes); zero means use " \
309 "MaxRAM * MaxRAMPercentage / 100") \
310 range(0, max_uintx) \
311 \
312 product(uintx, MaxRAMFraction, 4, \
313 "Maximum fraction (1/n) of real memory used for maximum heap " \
314 "size. " \
315 "Deprecated, use MaxRAMPercentage instead") \
316 range(1, max_uintx) \
317 \
318 product(uintx, MinRAMFraction, 2, \
319 "Minimum fraction (1/n) of real memory used for maximum heap " \
320 "size on systems with small physical memory size. " \
321 "Deprecated, use MinRAMPercentage instead") \
322 range(1, max_uintx) \
323 \
324 product(uintx, InitialRAMFraction, 64, \
325 "Fraction (1/n) of real memory used for initial heap size. " \
326 "Deprecated, use InitialRAMPercentage instead") \
327 range(1, max_uintx) \
328 \
329 product(double, MaxRAMPercentage, 25.0, \
330 "Maximum percentage of real memory used for maximum heap size") \
331 range(0.0, 100.0) \
332 \
333 product(double, MinRAMPercentage, 50.0, \
334 "Minimum percentage of real memory used for maximum heap" \
335 "size on systems with small physical memory size") \
336 range(0.0, 100.0) \
337 \
338 product(double, InitialRAMPercentage, 1.5625, \
339 "Percentage of real memory used for initial heap size") \
340 range(0.0, 100.0) \
341 \
342 product(int, ActiveProcessorCount, -1, \
343 "Specify the CPU count the VM should use and report as active") \
344 \
345 develop(uintx, MaxVirtMemFraction, 2, \
346 "Maximum fraction (1/n) of virtual memory used for ergonomically "\
347 "determining maximum heap size") \
348 range(1, max_uintx) \
349 \
350 product(bool, UseAdaptiveSizePolicy, true, \
351 "Use adaptive generation sizing policies") \
352 \
353 product(bool, UsePSAdaptiveSurvivorSizePolicy, true, \
354 "Use adaptive survivor sizing policies") \
355 \
356 product(bool, UseAdaptiveGenerationSizePolicyAtMinorCollection, true, \
357 "Use adaptive young-old sizing policies at minor collections") \
358 \
359 product(bool, UseAdaptiveGenerationSizePolicyAtMajorCollection, true, \
360 "Use adaptive young-old sizing policies at major collections") \
361 \
362 product(bool, UseAdaptiveSizePolicyWithSystemGC, false, \
363 "Include statistics from System.gc() for adaptive size policy") \
364 \
365 develop(intx, PSAdaptiveSizePolicyResizeVirtualSpaceAlot, -1, \
366 "Resize the virtual spaces of the young or old generations") \
367 range(-1, 1) \
368 \
369 product(uint, AdaptiveSizeThroughPutPolicy, 0, \
370 "Policy for changing generation size for throughput goals") \
371 range(0, 1) \
372 \
373 product(uintx, AdaptiveSizePolicyInitializingSteps, 20, \
374 "Number of steps where heuristics is used before data is used") \
375 range(0, max_uintx) \
376 \
377 develop(uintx, AdaptiveSizePolicyReadyThreshold, 5, \
378 "Number of collections before the adaptive sizing is started") \
379 \
380 product(uintx, AdaptiveSizePolicyOutputInterval, 0, \
381 "Collection interval for printing information; zero means never") \
382 range(0, max_uintx) \
383 \
384 product(bool, UseAdaptiveSizePolicyFootprintGoal, true, \
385 "Use adaptive minimum footprint as a goal") \
386 \
387 product(uint, AdaptiveSizePolicyWeight, 10, \
388 "Weight given to exponential resizing, between 0 and 100") \
389 range(0, 100) \
390 \
391 product(uint, AdaptiveTimeWeight, 25, \
392 "Weight given to time in adaptive policy, between 0 and 100") \
393 range(0, 100) \
394 \
395 product(uint, PausePadding, 1, \
396 "How much buffer to keep for pause time") \
397 range(0, UINT_MAX) \
398 \
399 product(uint, PromotedPadding, 3, \
400 "How much buffer to keep for promotion failure") \
401 range(0, UINT_MAX) \
402 \
403 product(uint, SurvivorPadding, 3, \
404 "How much buffer to keep for survivor overflow") \
405 range(0, UINT_MAX) \
406 \
407 product(uint, ThresholdTolerance, 10, \
408 "Allowed collection cost difference between generations") \
409 range(0, 100) \
410 \
411 product(uint, AdaptiveSizePolicyCollectionCostMargin, 50, \
412 "If collection costs are within margin, reduce both by full " \
413 "delta") \
414 range(0, 100) \
415 \
416 product(uint, YoungGenerationSizeIncrement, 20, \
417 "Adaptive size percentage change in young generation") \
418 range(0, 100) \
419 \
420 product(uint, YoungGenerationSizeSupplement, 80, \
421 "Supplement to YoungedGenerationSizeIncrement used at startup") \
422 range(0, 100) \
423 \
424 product(uintx, YoungGenerationSizeSupplementDecay, 8, \
425 "Decay factor to YoungedGenerationSizeSupplement") \
426 range(1, max_uintx) \
427 \
428 product(uint, TenuredGenerationSizeIncrement, 20, \
429 "Adaptive size percentage change in tenured generation") \
430 range(0, 100) \
431 \
432 product(uint, TenuredGenerationSizeSupplement, 80, \
433 "Supplement to TenuredGenerationSizeIncrement used at startup") \
434 range(0, 100) \
435 \
436 product(uintx, TenuredGenerationSizeSupplementDecay, 2, \
437 "Decay factor to TenuredGenerationSizeIncrement") \
438 range(1, max_uintx) \
439 \
440 product(uintx, MaxGCPauseMillis, max_uintx - 1, \
441 "Adaptive size policy maximum GC pause time goal in millisecond, "\
442 "or (G1 Only) the maximum GC time per MMU time slice") \
443 range(1, max_uintx - 1) \
444 constraint(MaxGCPauseMillisConstraintFunc,AfterErgo) \
445 \
446 product(uintx, GCPauseIntervalMillis, 0, \
447 "Time slice for MMU specification") \
448 constraint(GCPauseIntervalMillisConstraintFunc,AfterErgo) \
449 \
450 product(uintx, MaxGCMinorPauseMillis, max_uintx, \
451 "Adaptive size policy maximum GC minor pause time goal " \
452 "in millisecond") \
453 range(0, max_uintx) \
454 \
455 product(uint, GCTimeRatio, 99, \
456 "Adaptive size policy application time to GC time ratio") \
457 range(0, UINT_MAX) \
458 \
459 product(uintx, AdaptiveSizeDecrementScaleFactor, 4, \
460 "Adaptive size scale down factor for shrinking") \
461 range(1, max_uintx) \
462 \
463 product(bool, UseAdaptiveSizeDecayMajorGCCost, true, \
464 "Adaptive size decays the major cost for long major intervals") \
465 \
466 product(uintx, AdaptiveSizeMajorGCDecayTimeScale, 10, \
467 "Time scale over which major costs decay") \
468 range(0, max_uintx) \
469 \
470 product(uintx, MinSurvivorRatio, 3, \
471 "Minimum ratio of young generation/survivor space size") \
472 range(3, max_uintx) \
473 \
474 product(uintx, InitialSurvivorRatio, 8, \
475 "Initial ratio of young generation/survivor space size") \
476 range(0, max_uintx) \
477 \
478 product(size_t, BaseFootPrintEstimate, 256*M, \
479 "Estimate of footprint other than Java Heap") \
480 range(0, max_uintx) \
481 \
482 product(bool, UseGCOverheadLimit, true, \
483 "Use policy to limit of proportion of time spent in GC " \
484 "before an OutOfMemory error is thrown") \
485 \
486 product(uint, GCTimeLimit, 98, \
487 "Limit of the proportion of time spent in GC before " \
488 "an OutOfMemoryError is thrown (used with GCHeapFreeLimit)") \
489 range(0, 100) \
490 \
491 product(uint, GCHeapFreeLimit, 2, \
492 "Minimum percentage of free space after a full GC before an " \
493 "OutOfMemoryError is thrown (used with GCTimeLimit)") \
494 range(0, 100) \
495 \
496 develop(uintx, GCOverheadLimitThreshold, 5, \
497 "Number of consecutive collections before gc time limit fires") \
498 range(1, max_uintx) \
499 \
500 product(intx, PrefetchCopyIntervalInBytes, -1, \
501 "How far ahead to prefetch destination area (<= 0 means off)") \
502 range(-1, max_jint) \
503 \
504 product(intx, PrefetchScanIntervalInBytes, -1, \
505 "How far ahead to prefetch scan area (<= 0 means off)") \
506 range(-1, max_jint) \
507 \
508 product(bool, VerifyDuringStartup, false, DIAGNOSTIC, \
509 "Verify memory system before executing any Java code " \
510 "during VM initialization") \
511 \
512 product(bool, VerifyBeforeExit, trueInDebug, DIAGNOSTIC, \
513 "Verify system before exiting") \
514 \
515 product(bool, VerifyBeforeGC, false, DIAGNOSTIC, \
516 "Verify memory system before GC") \
517 \
518 product(bool, VerifyAfterGC, false, DIAGNOSTIC, \
519 "Verify memory system after GC") \
520 \
521 product(bool, VerifyDuringGC, false, DIAGNOSTIC, \
522 "Verify memory system during GC (between phases)") \
523 \
524 product(int, VerifyArchivedFields, 0, DIAGNOSTIC, \
525 "Verify memory when archived oop fields are loaded from CDS; " \
526 "0: No check; " \
527 "1: Basic verification with VM_Verify (no side effects); " \
528 "2: Detailed verification by forcing a GC (with side effects)") \
529 range(0, 2) \
530 \
531 product(ccstrlist, VerifyGCType, "", DIAGNOSTIC, \
532 "GC type(s) to verify when Verify*GC is enabled." \
533 "Available types are collector specific.") \
534 \
535 product(ccstrlist, VerifySubSet, "", DIAGNOSTIC, \
536 "Memory sub-systems to verify when Verify*GC flag(s) " \
537 "are enabled. One or more sub-systems can be specified " \
538 "in a comma separated string. Sub-systems are: " \
539 "threads, heap, symbol_table, string_table, codecache, " \
540 "dictionary, classloader_data_graph, metaspace, jni_handles, " \
541 "codecache_oops, resolved_method_table, stringdedup") \
542 \
543 product(bool, DeferInitialCardMark, false, DIAGNOSTIC, \
544 "When +ReduceInitialCardMarks, explicitly defer any that " \
545 "may arise from new_pre_store_barrier") \
546 \
547 product(bool, UseCondCardMark, false, \
548 "Check for already marked card before updating card table") \
549 \
550 product(bool, VerifyRememberedSets, false, DIAGNOSTIC, \
551 "Verify GC remembered sets") \
552 \
553 product(bool, VerifyObjectStartArray, true, DIAGNOSTIC, \
554 "Verify GC object start array if verify before/after") \
555 \
556 product(bool, DisableExplicitGC, false, \
557 "Ignore calls to System.gc()") \
558 \
559 product(bool, PrintGC, false, \
560 "Print message at garbage collection. " \
561 "Deprecated, use -Xlog:gc instead.") \
562 \
563 product(bool, PrintGCDetails, false, \
564 "Print more details at garbage collection. " \
565 "Deprecated, use -Xlog:gc* instead.") \
566 \
567 develop(intx, ConcGCYieldTimeout, 0, \
568 "If non-zero, assert that GC threads yield within this " \
569 "number of milliseconds") \
570 range(0, max_intx) \
571 \
572 notproduct(int, ScavengeALotInterval, 1, \
573 "Interval between which scavenge will occur with +ScavengeALot") \
574 \
575 notproduct(int, FullGCALotInterval, 1, \
576 "Interval between which full gc will occur with +FullGCALot") \
577 \
578 notproduct(int, FullGCALotStart, 0, \
579 "For which invocation to start FullGCAlot") \
580 \
581 notproduct(int, FullGCALotDummies, 32*K, \
582 "Dummy object allocated with +FullGCALot, forcing all objects " \
583 "to move") \
584 \
585 /* gc parameters */ \
586 product(size_t, MinHeapSize, 0, \
587 "Minimum heap size (in bytes); zero means use ergonomics") \
588 constraint(MinHeapSizeConstraintFunc,AfterErgo) \
589 \
590 product(size_t, InitialHeapSize, 0, \
591 "Initial heap size (in bytes); zero means use ergonomics") \
592 constraint(InitialHeapSizeConstraintFunc,AfterErgo) \
593 \
594 product(size_t, MaxHeapSize, ScaleForWordSize(96*M), \
595 "Maximum heap size (in bytes)") \
596 constraint(MaxHeapSizeConstraintFunc,AfterErgo) \
597 \
598 product(size_t, SoftMaxHeapSize, 0, MANAGEABLE, \
599 "Soft limit for maximum heap size (in bytes)") \
600 constraint(SoftMaxHeapSizeConstraintFunc,AfterMemoryInit) \
601 \
602 product(size_t, OldSize, ScaleForWordSize(4*M), \
603 "Initial tenured generation size (in bytes)") \
604 range(0, max_uintx) \
605 \
606 product(size_t, NewSize, ScaleForWordSize(1*M), \
607 "Initial new generation size (in bytes)") \
608 constraint(NewSizeConstraintFunc,AfterErgo) \
609 \
610 product(size_t, MaxNewSize, max_uintx, \
611 "Maximum new generation size (in bytes), max_uintx means set " \
612 "ergonomically") \
613 range(0, max_uintx) \
614 \
615 product_pd(size_t, HeapBaseMinAddress, \
616 "OS specific low limit for heap base address") \
617 constraint(HeapBaseMinAddressConstraintFunc,AfterErgo) \
618 \
619 product(size_t, PretenureSizeThreshold, 0, \
620 "Maximum size in bytes of objects allocated in DefNew " \
621 "generation; zero means no maximum") \
622 range(0, max_uintx) \
623 \
624 product(uintx, SurvivorRatio, 8, \
625 "Ratio of eden/survivor space size") \
626 range(1, max_uintx-2) \
627 constraint(SurvivorRatioConstraintFunc,AfterMemoryInit) \
628 \
629 product(uintx, NewRatio, 2, \
630 "Ratio of old/new generation sizes") \
631 range(0, max_uintx-1) \
632 \
633 product_pd(size_t, NewSizeThreadIncrease, \
634 "Additional size added to desired new generation size per " \
635 "non-daemon thread (in bytes)") \
636 range(0, max_uintx) \
637 \
638 product(uintx, QueuedAllocationWarningCount, 0, \
639 "Number of times an allocation that queues behind a GC " \
640 "will retry before printing a warning") \
641 range(0, max_uintx) \
642 \
643 product(uintx, VerifyGCStartAt, 0, DIAGNOSTIC, \
644 "GC invoke count where +VerifyBefore/AfterGC kicks in") \
645 range(0, max_uintx) \
646 \
647 product(int, VerifyGCLevel, 0, DIAGNOSTIC, \
648 "Generation level at which to start +VerifyBefore/AfterGC") \
649 range(0, 1) \
650 \
651 product(uint, MaxTenuringThreshold, 15, \
652 "Maximum value for tenuring threshold") \
653 range(0, markWord::max_age + 1) \
654 constraint(MaxTenuringThresholdConstraintFunc,AfterErgo) \
655 \
656 product(uint, InitialTenuringThreshold, 7, \
657 "Initial value for tenuring threshold") \
658 range(0, markWord::max_age + 1) \
659 constraint(InitialTenuringThresholdConstraintFunc,AfterErgo) \
660 \
661 product(uint, TargetSurvivorRatio, 50, \
662 "Desired percentage of survivor space used after scavenge") \
663 range(0, 100) \
664 \
665 product(uint, MarkSweepDeadRatio, 5, \
666 "Percentage (0-100) of the old gen allowed as dead wood. " \
667 "Serial mark sweep treats this as both the minimum and maximum " \
668 "value. " \
669 "Par compact uses a variable scale based on the density of the " \
670 "generation and treats this as the maximum value when the heap " \
671 "is either completely full or completely empty. Par compact " \
672 "also has a smaller default value; see arguments.cpp. " \
673 "G1 full gc treats this as an allowed garbage threshold to skip " \
674 "compaction of heap regions, i.e. if a heap region has less " \
675 "garbage than this value, then the region will not be compacted" \
676 "during G1 full GC.") \
677 range(0, 100) \
678 \
679 product(uint, MarkSweepAlwaysCompactCount, 4, \
680 "How often should we fully compact the heap (ignoring the dead " \
681 "space parameters)") \
682 range(1, UINT_MAX) \
683 \
684 develop(uintx, GCExpandToAllocateDelayMillis, 0, \
685 "Delay between expansion and allocation (in milliseconds)") \
686 \
687 product(uint, GCDrainStackTargetSize, 64, \
688 "Number of entries we will try to leave on the stack " \
689 "during parallel gc") \
690 range(0, 8 * 1024) \
691 \
692 product(uint, GCCardSizeInBytes, 512, \
693 "Card table entry size (in bytes) for card based collectors") \
694 range(128, NOT_LP64(512) LP64_ONLY(1024)) \
695 constraint(GCCardSizeInBytesConstraintFunc,AtParse) \
696 \
697 product(bool, UseAltGCForwarding, false, EXPERIMENTAL, \
698 "Use alternative GC forwarding that preserves object headers") \
699
700 // end of GC_FLAGS
701
702 DECLARE_FLAGS(GC_FLAGS)
703
704 #endif // SHARE_GC_SHARED_GC_GLOBALS_HPP