1 /*
2 * Copyright (c) 1997, 2024, 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 *
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10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
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13 * accompanied this code).
14 *
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23 */
24
25 #ifndef SHARE_RUNTIME_GLOBALS_HPP
26 #define SHARE_RUNTIME_GLOBALS_HPP
27
28 #include "compiler/compiler_globals_pd.hpp"
29 #include "runtime/globals_shared.hpp"
30 #include "utilities/align.hpp"
31 #include "utilities/globalDefinitions.hpp"
32 #include "utilities/macros.hpp"
33 #include CPU_HEADER(globals)
34 #include OS_HEADER(globals)
35 #include OS_CPU_HEADER(globals)
36
37 // develop flags are settable / visible only during development and are constant in the PRODUCT version
38 // product flags are always settable / visible
39 // develop_pd/product_pd flags are the same as develop/product, except that their default values
40 // are specified in platform-dependent header files.
41
42 // Flags must be declared with the following number of parameters:
43 // non-pd flags:
44 // (type, name, default_value, doc), or
45 // (type, name, default_value, extra_attrs, doc)
46 // pd flags:
47 // (type, name, doc), or
48 // (type, name, extra_attrs, doc)
49
50 // A flag must be declared with one of the following types:
51 // bool, int, uint, intx, uintx, size_t, ccstr, ccstrlist, double, or uint64_t.
52 // The type "ccstr" and "ccstrlist" are an alias for "const char*" and is used
53 // only in this file, because the macrology requires single-token type names.
54
55 // The optional extra_attrs parameter may have one of the following values:
56 // DIAGNOSTIC, EXPERIMENTAL, or MANAGEABLE. Currently extra_attrs can be used
57 // only with product/product_pd flags.
58 //
59 // DIAGNOSTIC options are not meant for VM tuning or for product modes.
60 // They are to be used for VM quality assurance or field diagnosis
61 // of VM bugs. They are hidden so that users will not be encouraged to
62 // try them as if they were VM ordinary execution options. However, they
63 // are available in the product version of the VM. Under instruction
64 // from support engineers, VM customers can turn them on to collect
65 // diagnostic information about VM problems. To use a VM diagnostic
66 // option, you must first specify +UnlockDiagnosticVMOptions.
67 // (This master switch also affects the behavior of -Xprintflags.)
68 //
69 // EXPERIMENTAL flags are in support of features that may not be
70 // an officially supported part of a product, but may be available
71 // for experimenting with. They could, for example, be performance
72 // features that may not have undergone full or rigorous QA, but which may
73 // help performance in some cases and released for experimentation
74 // by the community of users and developers. This flag also allows one to
75 // be able to build a fully supported product that nonetheless also
76 // ships with some unsupported, lightly tested, experimental features.
77 // Refer to the documentation of any products using this code for details
78 // on support and fitness for production.
79 // Like the UnlockDiagnosticVMOptions flag above, there is a corresponding
80 // UnlockExperimentalVMOptions flag, which allows the control and
81 // modification of the experimental flags.
82 //
83 // Nota bene: neither diagnostic nor experimental options should be used casually,
84 // Refer to the documentation of any products using this code for details.
85 //
86 // MANAGEABLE flags are writeable external product flags.
87 // They are dynamically writeable through the JDK management interface
88 // (com.sun.management.HotSpotDiagnosticMXBean API) and also through JConsole.
89 // These flags are external exported interface (see CSR). The list of
90 // manageable flags can be queried programmatically through the management
91 // interface.
92 //
93 // A flag can be made as "manageable" only if
94 // - the flag is defined in a CSR request as an external exported interface.
95 // - the VM implementation supports dynamic setting of the flag.
96 // This implies that the VM must *always* query the flag variable
97 // and not reuse state related to the flag state at any given time.
98 // - you want the flag to be queried programmatically by the customers.
99 //
100
101 //
102 // range is a macro that will expand to min and max arguments for range
103 // checking code if provided - see jvmFlagLimit.hpp
104 //
105 // constraint is a macro that will expand to custom function call
106 // for constraint checking if provided - see jvmFlagLimit.hpp
107
108 // Default and minimum StringTable and SymbolTable size values
109 // Must be powers of 2
110 const size_t defaultStringTableSize = NOT_LP64(1024) LP64_ONLY(65536);
111 const size_t minimumStringTableSize = 128;
112 const size_t defaultSymbolTableSize = 32768; // 2^15
113 const size_t minimumSymbolTableSize = 1024;
114
115 #ifdef _LP64
116 #define LP64_RUNTIME_FLAGS(develop, \
117 develop_pd, \
118 product, \
119 product_pd, \
120 range, \
121 constraint) \
122 \
123 product(bool, UseCompressedOops, false, \
124 "Use 32-bit object references in 64-bit VM. " \
125 "lp64_product means flag is always constant in 32 bit VM") \
126 \
127 product(bool, UseCompressedClassPointers, true, \
128 "Use 32-bit class pointers in 64-bit VM. " \
129 "lp64_product means flag is always constant in 32 bit VM") \
130 \
131 /* Leyden */ \
132 product(bool, UseCompatibleCompressedOops, false, \
133 "Always use HeapBasedNarrowOop mode, so that AOT code can be " \
134 "always work regardless of runtime heap range") \
135 \
136 product(int, ObjectAlignmentInBytes, 8, \
137 "Default object alignment in bytes, 8 is minimum") \
138 range(8, 256) \
139 constraint(ObjectAlignmentInBytesConstraintFunc, AtParse)
140
141 #else
142 // !_LP64
143
144 #define LP64_RUNTIME_FLAGS(develop, \
145 develop_pd, \
146 product, \
147 product_pd, \
148 range, \
149 constraint)
150 const bool UseCompressedOops = false;
151 const bool UseCompressedClassPointers = false;
152 const int ObjectAlignmentInBytes = 8;
153
154 #endif // _LP64
155
156 #define RUNTIME_FLAGS(develop, \
157 develop_pd, \
158 product, \
159 product_pd, \
160 range, \
161 constraint) \
162 \
163 develop(bool, CheckCompressedOops, true, \
164 "Generate checks in encoding/decoding code in debug VM") \
165 \
166 product(uintx, HeapSearchSteps, 3 PPC64_ONLY(+17), \
167 "Heap allocation steps through preferred address regions to find" \
168 " where it can allocate the heap. Number of steps to take per " \
169 "region.") \
170 range(1, max_uintx) \
171 \
172 product(uint, HandshakeTimeout, 0, DIAGNOSTIC, \
173 "If nonzero set a timeout in milliseconds for handshakes") \
174 \
175 product(bool, AlwaysSafeConstructors, false, EXPERIMENTAL, \
176 "Force safe construction, as if all fields are final.") \
177 \
178 product(bool, UnlockDiagnosticVMOptions, trueInDebug, DIAGNOSTIC, \
179 "Enable normal processing of flags relating to field diagnostics")\
180 \
181 product(bool, UnlockExperimentalVMOptions, false, EXPERIMENTAL, \
182 "Enable normal processing of flags relating to experimental " \
183 "features") \
184 \
185 product(bool, JavaMonitorsInStackTrace, true, \
186 "Print information about Java monitor locks when the stacks are " \
187 "dumped") \
188 \
189 product_pd(bool, UseLargePages, \
190 "Use large page memory") \
191 \
192 product_pd(bool, UseLargePagesIndividualAllocation, \
193 "Allocate large pages individually for better affinity") \
194 \
195 develop(bool, LargePagesIndividualAllocationInjectError, false, \
196 "Fail large pages individual allocation") \
197 \
198 product(bool, UseNUMA, false, \
199 "Use NUMA if available") \
200 \
201 product(bool, UseNUMAInterleaving, false, \
202 "Interleave memory across NUMA nodes if available") \
203 \
204 product(size_t, NUMAInterleaveGranularity, 2*M, \
205 "Granularity to use for NUMA interleaving on Windows OS") \
206 constraint(NUMAInterleaveGranularityConstraintFunc, AtParse) \
207 \
208 product(uintx, NUMAChunkResizeWeight, 20, \
209 "Percentage (0-100) used to weight the current sample when " \
210 "computing exponentially decaying average for " \
211 "AdaptiveNUMAChunkSizing") \
212 range(0, 100) \
213 \
214 product(size_t, NUMASpaceResizeRate, 1*G, \
215 "Do not reallocate more than this amount per collection") \
216 range(0, max_uintx) \
217 \
218 product(bool, UseAdaptiveNUMAChunkSizing, true, \
219 "Enable adaptive chunk sizing for NUMA") \
220 \
221 product(bool, NUMAStats, false, \
222 "Print NUMA stats in detailed heap information") \
223 \
224 product(bool, UseAES, false, \
225 "Control whether AES instructions are used when available") \
226 \
227 product(bool, UseFMA, false, \
228 "Control whether FMA instructions are used when available") \
229 \
230 product(bool, UseSHA, false, \
231 "Control whether SHA instructions are used when available") \
232 \
233 product(bool, UseGHASHIntrinsics, false, DIAGNOSTIC, \
234 "Use intrinsics for GHASH versions of crypto") \
235 \
236 product(bool, UseBASE64Intrinsics, false, \
237 "Use intrinsics for java.util.Base64") \
238 \
239 product(bool, UsePoly1305Intrinsics, false, DIAGNOSTIC, \
240 "Use intrinsics for sun.security.util.math.intpoly") \
241 product(bool, UseIntPolyIntrinsics, false, DIAGNOSTIC, \
242 "Use intrinsics for sun.security.util.math.intpoly.MontgomeryIntegerPolynomialP256") \
243 \
244 product(size_t, LargePageSizeInBytes, 0, \
245 "Maximum large page size used (0 will use the default large " \
246 "page size for the environment as the maximum)") \
247 range(0, max_uintx) \
248 \
249 product(size_t, LargePageHeapSizeThreshold, 128*M, \
250 "Use large pages if maximum heap is at least this big") \
251 range(0, max_uintx) \
252 \
253 product(bool, ForceTimeHighResolution, false, \
254 "Using high time resolution (for Win32 only)") \
255 \
256 develop(bool, TracePcPatching, false, \
257 "Trace usage of frame::patch_pc") \
258 \
259 develop(bool, TraceRelocator, false, \
260 "Trace the bytecode relocator") \
261 \
262 \
263 product(bool, SafepointALot, false, DIAGNOSTIC, \
264 "Generate a lot of safepoints. This works with " \
265 "GuaranteedSafepointInterval") \
266 \
267 product(bool, HandshakeALot, false, DIAGNOSTIC, \
268 "Generate a lot of handshakes. This works with " \
269 "GuaranteedSafepointInterval") \
270 \
271 product_pd(bool, BackgroundCompilation, \
272 "A thread requesting compilation is not blocked during " \
273 "compilation") \
274 \
275 product(bool, MethodFlushing, true, \
276 "Reclamation of compiled methods") \
277 \
278 develop(bool, VerifyStack, false, \
279 "Verify stack of each thread when it is entering a runtime call") \
280 \
281 product(bool, ForceUnreachable, false, DIAGNOSTIC, \
282 "Make all non code cache addresses to be unreachable by " \
283 "forcing use of 64bit literal fixups") \
284 \
285 develop(bool, TraceDerivedPointers, false, \
286 "Trace traversal of derived pointers on stack") \
287 \
288 develop(bool, TraceCodeBlobStacks, false, \
289 "Trace stack-walk of codeblobs") \
290 \
291 develop(bool, PrintRewrites, false, \
292 "Print methods that are being rewritten") \
293 \
294 product(bool, UseInlineCaches, true, \
295 "Use Inline Caches for virtual calls ") \
296 \
297 product(bool, InlineArrayCopy, true, DIAGNOSTIC, \
298 "Inline arraycopy native that is known to be part of " \
299 "base library DLL") \
300 \
301 product(bool, InlineObjectHash, true, DIAGNOSTIC, \
302 "Inline Object::hashCode() native that is known to be part " \
303 "of base library DLL") \
304 \
305 product(bool, InlineNatives, true, DIAGNOSTIC, \
306 "Inline natives that are known to be part of base library DLL") \
307 \
308 product(bool, InlineMathNatives, true, DIAGNOSTIC, \
309 "Inline SinD, CosD, etc.") \
310 \
311 product(bool, InlineClassNatives, true, DIAGNOSTIC, \
312 "Inline Class.isInstance, etc") \
313 \
314 product(bool, InlineThreadNatives, true, DIAGNOSTIC, \
315 "Inline Thread.currentThread, etc") \
316 \
317 product(bool, InlineUnsafeOps, true, DIAGNOSTIC, \
318 "Inline memory ops (native methods) from Unsafe") \
319 \
320 product(bool, UseAESIntrinsics, false, DIAGNOSTIC, \
321 "Use intrinsics for AES versions of crypto") \
322 \
323 product(bool, UseAESCTRIntrinsics, false, DIAGNOSTIC, \
324 "Use intrinsics for the paralleled version of AES/CTR crypto") \
325 \
326 product(bool, UseChaCha20Intrinsics, false, DIAGNOSTIC, \
327 "Use intrinsics for the vectorized version of ChaCha20") \
328 \
329 product(bool, UseMD5Intrinsics, false, DIAGNOSTIC, \
330 "Use intrinsics for MD5 crypto hash function") \
331 \
332 product(bool, UseSHA1Intrinsics, false, DIAGNOSTIC, \
333 "Use intrinsics for SHA-1 crypto hash function. " \
334 "Requires that UseSHA is enabled.") \
335 \
336 product(bool, UseSHA256Intrinsics, false, DIAGNOSTIC, \
337 "Use intrinsics for SHA-224 and SHA-256 crypto hash functions. " \
338 "Requires that UseSHA is enabled.") \
339 \
340 product(bool, UseSHA512Intrinsics, false, DIAGNOSTIC, \
341 "Use intrinsics for SHA-384 and SHA-512 crypto hash functions. " \
342 "Requires that UseSHA is enabled.") \
343 \
344 product(bool, UseSHA3Intrinsics, false, DIAGNOSTIC, \
345 "Use intrinsics for SHA3 crypto hash function. " \
346 "Requires that UseSHA is enabled.") \
347 \
348 product(bool, UseCRC32Intrinsics, false, DIAGNOSTIC, \
349 "use intrinsics for java.util.zip.CRC32") \
350 \
351 product(bool, UseCRC32CIntrinsics, false, DIAGNOSTIC, \
352 "use intrinsics for java.util.zip.CRC32C") \
353 \
354 product(bool, UseAdler32Intrinsics, false, DIAGNOSTIC, \
355 "use intrinsics for java.util.zip.Adler32") \
356 \
357 product(bool, UseVectorizedMismatchIntrinsic, false, DIAGNOSTIC, \
358 "Enables intrinsification of ArraysSupport.vectorizedMismatch()") \
359 \
360 product(bool, UseVectorizedHashCodeIntrinsic, false, DIAGNOSTIC, \
361 "Enables intrinsification of ArraysSupport.vectorizedHashCode()") \
362 \
363 product(bool, UseCopySignIntrinsic, false, DIAGNOSTIC, \
364 "Enables intrinsification of Math.copySign") \
365 \
366 product(bool, UseSignumIntrinsic, false, DIAGNOSTIC, \
367 "Enables intrinsification of Math.signum") \
368 \
369 product_pd(bool, DelayCompilerStubsGeneration, DIAGNOSTIC, \
370 "Use Compiler thread for compiler's stubs generation") \
371 \
372 product(ccstrlist, DisableIntrinsic, "", DIAGNOSTIC, \
373 "do not expand intrinsics whose (internal) names appear here") \
374 constraint(DisableIntrinsicConstraintFunc,AfterErgo) \
375 \
376 product(ccstrlist, ControlIntrinsic, "", DIAGNOSTIC, \
377 "Control intrinsics using a list of +/- (internal) names, " \
378 "separated by commas") \
379 constraint(ControlIntrinsicConstraintFunc,AfterErgo) \
380 \
381 develop(bool, TraceCallFixup, false, \
382 "Trace all call fixups") \
383 \
384 develop(bool, DeoptimizeALot, false, \
385 "Deoptimize at every exit from the runtime system") \
386 \
387 develop(ccstrlist, DeoptimizeOnlyAt, "", \
388 "A comma separated list of bcis to deoptimize at") \
389 \
390 develop(bool, DeoptimizeRandom, false, \
391 "Deoptimize random frames on random exit from the runtime system")\
392 \
393 develop(bool, ZombieALot, false, \
394 "Create non-entrant nmethods at exit from the runtime system") \
395 \
396 develop(bool, WalkStackALot, false, \
397 "Trace stack (no print) at every exit from the runtime system") \
398 \
399 develop(bool, DeoptimizeObjectsALot, false, \
400 "For testing purposes concurrent threads revert optimizations " \
401 "based on escape analysis at intervals given with " \
402 "DeoptimizeObjectsALotInterval=n. The thread count is given " \
403 "with DeoptimizeObjectsALotThreadCountSingle and " \
404 "DeoptimizeObjectsALotThreadCountAll.") \
405 \
406 develop(uint64_t, DeoptimizeObjectsALotInterval, 5, \
407 "Interval for DeoptimizeObjectsALot.") \
408 range(0, max_jlong) \
409 \
410 develop(int, DeoptimizeObjectsALotThreadCountSingle, 1, \
411 "The number of threads that revert optimizations based on " \
412 "escape analysis for a single thread if DeoptimizeObjectsALot " \
413 "is enabled. The target thread is selected round robin." ) \
414 range(0, max_jint) \
415 \
416 develop(int, DeoptimizeObjectsALotThreadCountAll, 1, \
417 "The number of threads that revert optimizations based on " \
418 "escape analysis for all threads if DeoptimizeObjectsALot " \
419 "is enabled." ) \
420 range(0, max_jint) \
421 \
422 develop(bool, VerifyLastFrame, false, \
423 "Verify oops on last frame on entry to VM") \
424 \
425 product(bool, SafepointTimeout, false, \
426 "Time out and warn or fail after SafepointTimeoutDelay " \
427 "milliseconds if failed to reach safepoint") \
428 \
429 product(bool, AbortVMOnSafepointTimeout, false, DIAGNOSTIC, \
430 "Abort upon failure to reach safepoint (see SafepointTimeout)") \
431 \
432 product(uint64_t, AbortVMOnSafepointTimeoutDelay, 0, DIAGNOSTIC, \
433 "Delay in milliseconds for option AbortVMOnSafepointTimeout") \
434 range(0, max_jlong) \
435 \
436 product(bool, AbortVMOnVMOperationTimeout, false, DIAGNOSTIC, \
437 "Abort upon failure to complete VM operation promptly") \
438 \
439 product(intx, AbortVMOnVMOperationTimeoutDelay, 1000, DIAGNOSTIC, \
440 "Delay in milliseconds for option AbortVMOnVMOperationTimeout") \
441 range(0, max_intx) \
442 \
443 product(bool, MaxFDLimit, true, \
444 "Bump the number of file descriptors to maximum (Unix only)") \
445 \
446 product(bool, LogEvents, true, DIAGNOSTIC, \
447 "Enable the various ring buffer event logs") \
448 \
449 product(int, LogEventsBufferEntries, 20, DIAGNOSTIC, \
450 "Number of ring buffer event logs") \
451 range(1, NOT_LP64(1*K) LP64_ONLY(1*M)) \
452 \
453 product(bool, BytecodeVerificationRemote, true, DIAGNOSTIC, \
454 "Enable the Java bytecode verifier for remote classes") \
455 \
456 product(bool, BytecodeVerificationLocal, false, DIAGNOSTIC, \
457 "Enable the Java bytecode verifier for local classes") \
458 \
459 develop(bool, VerifyStackAtCalls, false, \
460 "Verify that the stack pointer is unchanged after calls") \
461 \
462 develop(bool, TraceJavaAssertions, false, \
463 "Trace java language assertions") \
464 \
465 develop(bool, VerifyCodeCache, false, \
466 "Verify code cache on memory allocation/deallocation") \
467 \
468 develop(bool, ZapResourceArea, trueInDebug, \
469 "Zap freed resource/arena space") \
470 \
471 develop(bool, ZapVMHandleArea, trueInDebug, \
472 "Zap freed VM handle space") \
473 \
474 develop(bool, ZapStackSegments, trueInDebug, \
475 "Zap allocated/freed stack segments") \
476 \
477 develop(bool, ZapUnusedHeapArea, trueInDebug, \
478 "Zap unused heap space") \
479 \
480 develop(bool, ZapFillerObjects, trueInDebug, \
481 "Zap filler objects") \
482 \
483 develop(bool, ZapTLAB, trueInDebug, \
484 "Zap allocated TLABs") \
485 \
486 product(bool, ExecutingUnitTests, false, \
487 "Whether the JVM is running unit tests or not") \
488 \
489 develop(uint, ErrorHandlerTest, 0, \
490 "If > 0, provokes an error after VM initialization; the value " \
491 "determines which error to provoke. See controlled_crash() " \
492 "in vmError.cpp.") \
493 range(0, 17) \
494 \
495 develop(uint, TestCrashInErrorHandler, 0, \
496 "If > 0, provokes an error inside VM error handler (a secondary " \
497 "crash). see controlled_crash() in vmError.cpp") \
498 range(0, 17) \
499 \
500 develop(bool, TestSafeFetchInErrorHandler, false , \
501 "If true, tests SafeFetch inside error handler.") \
502 \
503 develop(bool, TestUnresponsiveErrorHandler, false, \
504 "If true, simulates an unresponsive error handler.") \
505 \
506 develop(bool, Verbose, false, \
507 "Print additional debugging information from other modes") \
508 \
509 develop(bool, PrintMiscellaneous, false, \
510 "Print uncategorized debugging information (requires +Verbose)") \
511 \
512 develop(bool, WizardMode, false, \
513 "Print much more debugging information") \
514 \
515 product(bool, ShowMessageBoxOnError, false, \
516 "Keep process alive on VM fatal error") \
517 \
518 product(bool, CreateCoredumpOnCrash, true, \
519 "Create core/mini dump on VM fatal error") \
520 \
521 product(uint64_t, ErrorLogTimeout, 2 * 60, \
522 "Timeout, in seconds, to limit the time spent on writing an " \
523 "error log in case of a crash.") \
524 range(0, (uint64_t)max_jlong/1000) \
525 \
526 product(bool, ErrorLogSecondaryErrorDetails, false, DIAGNOSTIC, \
527 "If enabled, show details on secondary crashes in the error log") \
528 \
529 develop(intx, TraceDwarfLevel, 0, \
530 "Debug levels for the dwarf parser") \
531 range(0, 4) \
532 \
533 product(bool, SuppressFatalErrorMessage, false, \
534 "Report NO fatal error message (avoid deadlock)") \
535 \
536 product(ccstrlist, OnError, "", \
537 "Run user-defined commands on fatal error; see VMError.cpp " \
538 "for examples") \
539 \
540 product(ccstrlist, OnOutOfMemoryError, "", \
541 "Run user-defined commands on first java.lang.OutOfMemoryError " \
542 "thrown from JVM") \
543 \
544 product(bool, HeapDumpBeforeFullGC, false, MANAGEABLE, \
545 "Dump heap to file before any major stop-the-world GC " \
546 "(also see FullGCHeapDumpLimit, HeapDumpPath, HeapDumpGzipLevel)")\
547 \
548 product(bool, HeapDumpAfterFullGC, false, MANAGEABLE, \
549 "Dump heap to file after any major stop-the-world GC " \
550 "(also see FullGCHeapDumpLimit, HeapDumpPath, HeapDumpGzipLevel)")\
551 \
552 product(uint, FullGCHeapDumpLimit, 0, MANAGEABLE, \
553 "Limit the number of heap dumps triggered by " \
554 "HeapDumpBeforeFullGC or HeapDumpAfterFullGC " \
555 "(0 means no limit)") \
556 \
557 product(bool, HeapDumpOnOutOfMemoryError, false, MANAGEABLE, \
558 "Dump heap to file when java.lang.OutOfMemoryError is thrown " \
559 "from JVM " \
560 "(also see HeapDumpPath, HeapDumpGzipLevel)") \
561 \
562 product(ccstr, HeapDumpPath, nullptr, MANAGEABLE, \
563 "When HeapDumpOnOutOfMemoryError, HeapDumpBeforeFullGC " \
564 "or HeapDumpAfterFullGC is on, the path (filename or " \
565 "directory) of the dump file (defaults to java_pid<pid>.hprof " \
566 "in the working directory)") \
567 \
568 product(int, HeapDumpGzipLevel, 0, MANAGEABLE, \
569 "When HeapDumpOnOutOfMemoryError, HeapDumpBeforeFullGC " \
570 "or HeapDumpAfterFullGC is on, the gzip compression " \
571 "level of the dump file. 0 (the default) disables gzip " \
572 "compression. Otherwise the level must be between 1 and 9.") \
573 range(0, 9) \
574 \
575 product(ccstr, NativeMemoryTracking, DEBUG_ONLY("summary") NOT_DEBUG("off"), \
576 "Native memory tracking options") \
577 \
578 product(bool, PrintNMTStatistics, false, DIAGNOSTIC, \
579 "Print native memory tracking summary data if it is on") \
580 \
581 product(bool, LogCompilation, false, DIAGNOSTIC, \
582 "Log compilation activity in detail to LogFile") \
583 \
584 product(bool, PrintCompilation, false, \
585 "Print compilations") \
586 \
587 product(intx, RepeatCompilation, 0, DIAGNOSTIC, \
588 "Repeat compilation without installing code (number of times)") \
589 range(0, max_jint) \
590 \
591 product(bool, PrintExtendedThreadInfo, false, \
592 "Print more information in thread dump") \
593 \
594 product(intx, ScavengeRootsInCode, 2, DIAGNOSTIC, \
595 "0: do not allow scavengable oops in the code cache; " \
596 "1: allow scavenging from the code cache; " \
597 "2: emit as many constants as the compiler can see") \
598 range(0, 2) \
599 \
600 product(bool, AlwaysRestoreFPU, false, \
601 "Restore the FPU control word after every JNI call (expensive)") \
602 \
603 product(bool, PrintCompilation2, false, DIAGNOSTIC, \
604 "Print additional statistics per compilation") \
605 \
606 product(bool, PrintAdapterHandlers, false, DIAGNOSTIC, \
607 "Print code generated for i2c/c2i adapters") \
608 \
609 product(bool, VerifyAdapterCalls, trueInDebug, DIAGNOSTIC, \
610 "Verify that i2c/c2i adapters are called properly") \
611 \
612 develop(bool, VerifyAdapterSharing, false, \
613 "Verify that the code for shared adapters is the equivalent") \
614 \
615 product(bool, PrintAssembly, false, DIAGNOSTIC, \
616 "Print assembly code (using external disassembler.so)") \
617 \
618 product(ccstr, PrintAssemblyOptions, nullptr, DIAGNOSTIC, \
619 "Print options string passed to disassembler.so") \
620 \
621 develop(bool, PrintNMethodStatistics, false, \
622 "Print a summary statistic for the generated nmethods") \
623 \
624 product(bool, PrintNMethods, false, DIAGNOSTIC, \
625 "Print assembly code for nmethods when generated") \
626 \
627 product(bool, PrintNativeNMethods, false, DIAGNOSTIC, \
628 "Print assembly code for native nmethods when generated") \
629 \
630 develop(bool, PrintDebugInfo, false, \
631 "Print debug information for all nmethods when generated") \
632 \
633 develop(bool, PrintRelocations, false, \
634 "Print relocation information for all nmethods when generated") \
635 \
636 develop(bool, PrintDependencies, false, \
637 "Print dependency information for all nmethods when generated") \
638 \
639 develop(bool, PrintExceptionHandlers, false, \
640 "Print exception handler tables for all nmethods when generated") \
641 \
642 develop(bool, StressCompiledExceptionHandlers, false, \
643 "Exercise compiled exception handlers") \
644 \
645 develop(bool, InterceptOSException, false, \
646 "Start debugger when an implicit OS (e.g. null pointer) " \
647 "exception happens") \
648 \
649 product(bool, PrintCodeCache, false, \
650 "Print the code cache memory usage when exiting") \
651 \
652 develop(bool, PrintCodeCache2, false, \
653 "Print detailed usage information on the code cache when exiting")\
654 \
655 product(bool, PrintCodeCacheOnCompilation, false, \
656 "Print the code cache memory usage each time a method is " \
657 "compiled") \
658 \
659 product(bool, PrintCodeHeapAnalytics, false, DIAGNOSTIC, \
660 "Print code heap usage statistics on exit and on full condition") \
661 \
662 product(bool, PrintStubCode, false, DIAGNOSTIC, \
663 "Print generated stub code") \
664 \
665 product(bool, StackTraceInThrowable, true, \
666 "Collect backtrace in throwable when exception happens") \
667 \
668 product(bool, OmitStackTraceInFastThrow, true, \
669 "Omit backtraces for some 'hot' exceptions in optimized code") \
670 \
671 product(bool, ShowCodeDetailsInExceptionMessages, true, MANAGEABLE, \
672 "Show exception messages from RuntimeExceptions that contain " \
673 "snippets of the failing code. Disable this to improve privacy.") \
674 \
675 product(bool, PrintWarnings, true, \
676 "Print JVM warnings to output stream") \
677 \
678 develop(bool, RegisterReferences, true, \
679 "Tell whether the VM should register soft/weak/final/phantom " \
680 "references") \
681 \
682 develop(bool, PrintCodeCacheExtension, false, \
683 "Print extension of code cache") \
684 \
685 develop(bool, UsePrivilegedStack, true, \
686 "Enable the security JVM functions") \
687 \
688 product(bool, ClassUnloading, true, \
689 "Do unloading of classes") \
690 \
691 product(bool, ClassUnloadingWithConcurrentMark, true, \
692 "Do unloading of classes with a concurrent marking cycle") \
693 \
694 develop(bool, PrintSystemDictionaryAtExit, false, \
695 "Print the system dictionary at exit") \
696 \
697 develop(bool, PrintClassLoaderDataGraphAtExit, false, \
698 "Print the class loader data graph at exit") \
699 \
700 product(bool, AllowParallelDefineClass, false, \
701 "Allow parallel defineClass requests for class loaders " \
702 "registering as parallel capable") \
703 \
704 product_pd(bool, DontYieldALot, \
705 "(Deprecated) Throw away obvious excess yield calls") \
706 \
707 product(bool, DisablePrimordialThreadGuardPages, false, EXPERIMENTAL, \
708 "Disable the use of stack guard pages if the JVM is loaded " \
709 "on the primordial process thread") \
710 \
711 product(bool, DoJVMTIVirtualThreadTransitions, true, EXPERIMENTAL, \
712 "Do JVMTI virtual thread mount/unmount transitions " \
713 "(disabling this flag implies no JVMTI events are posted)") \
714 \
715 /* notice: the max range value here is max_jint, not max_intx */ \
716 /* because of overflow issue */ \
717 product(intx, AsyncDeflationInterval, 250, DIAGNOSTIC, \
718 "Async deflate idle monitors every so many milliseconds when " \
719 "MonitorUsedDeflationThreshold is exceeded (0 is off).") \
720 range(0, max_jint) \
721 \
722 /* notice: the max range value here is max_jint, not max_intx */ \
723 /* because of overflow issue */ \
724 product(intx, GuaranteedAsyncDeflationInterval, 60000, DIAGNOSTIC, \
725 "Async deflate idle monitors every so many milliseconds even " \
726 "when MonitorUsedDeflationThreshold is NOT exceeded (0 is off).") \
727 range(0, max_jint) \
728 \
729 product(size_t, AvgMonitorsPerThreadEstimate, 1024, DIAGNOSTIC, \
730 "Used to estimate a variable ceiling based on number of threads " \
731 "for use with MonitorUsedDeflationThreshold (0 is off).") \
732 range(0, max_uintx) \
733 \
734 /* notice: the max range value here is max_jint, not max_intx */ \
735 /* because of overflow issue */ \
736 product(intx, MonitorDeflationMax, 1000000, DIAGNOSTIC, \
737 "The maximum number of monitors to deflate, unlink and delete " \
738 "at one time (minimum is 1024).") \
739 range(1024, max_jint) \
740 \
741 product(intx, MonitorUnlinkBatch, 500, DIAGNOSTIC, \
742 "The maximum number of monitors to unlink in one batch. ") \
743 range(1, max_jint) \
744 \
745 product(int, MonitorUsedDeflationThreshold, 90, DIAGNOSTIC, \
746 "Percentage of used monitors before triggering deflation (0 is " \
747 "off). The check is performed on AsyncDeflationInterval or " \
748 "GuaranteedAsyncDeflationInterval, whichever is lower.") \
749 range(0, 100) \
750 \
751 product(uintx, NoAsyncDeflationProgressMax, 3, DIAGNOSTIC, \
752 "Max number of no progress async deflation attempts to tolerate " \
753 "before adjusting the in_use_list_ceiling up (0 is off).") \
754 range(0, max_uintx) \
755 \
756 product(intx, hashCode, 5, EXPERIMENTAL, \
757 "(Unstable) select hashCode generation algorithm") \
758 \
759 product(bool, ReduceSignalUsage, false, \
760 "Reduce the use of OS signals in Java and/or the VM") \
761 \
762 develop(bool, LoadLineNumberTables, true, \
763 "Tell whether the class file parser loads line number tables") \
764 \
765 develop(bool, LoadLocalVariableTables, true, \
766 "Tell whether the class file parser loads local variable tables") \
767 \
768 develop(bool, LoadLocalVariableTypeTables, true, \
769 "Tell whether the class file parser loads local variable type" \
770 "tables") \
771 \
772 product(bool, AllowUserSignalHandlers, false, \
773 "Application will install primary signal handlers for the JVM " \
774 "(Unix only)") \
775 \
776 product(bool, UseSignalChaining, true, \
777 "Use signal-chaining to invoke signal handlers installed " \
778 "by the application (Unix only)") \
779 \
780 product(bool, RestoreMXCSROnJNICalls, false, \
781 "Restore MXCSR when returning from JNI calls") \
782 \
783 product(bool, CheckJNICalls, false, \
784 "Verify all arguments to JNI calls") \
785 \
786 product(bool, UseFastJNIAccessors, true, \
787 "Use optimized versions of Get<Primitive>Field") \
788 \
789 product(intx, MaxJNILocalCapacity, 65536, \
790 "Maximum allowable local JNI handle capacity to " \
791 "EnsureLocalCapacity() and PushLocalFrame(), " \
792 "where <= 0 is unlimited, default: 65536") \
793 range(min_intx, max_intx) \
794 \
795 product(bool, EagerXrunInit, false, \
796 "Eagerly initialize -Xrun libraries; allows startup profiling, " \
797 "but not all -Xrun libraries may support the state of the VM " \
798 "at this time") \
799 \
800 develop(uintx, PreallocatedOutOfMemoryErrorCount, 4, \
801 "Number of OutOfMemoryErrors preallocated with backtrace") \
802 \
803 product(bool, UseXMMForArrayCopy, false, \
804 "Use SSE2 MOVQ instruction for Arraycopy") \
805 \
806 develop(bool, PrintFieldLayout, false, \
807 "Print field layout for each class") \
808 \
809 /* Need to limit the extent of the padding to reasonable size. */\
810 /* 8K is well beyond the reasonable HW cache line size, even with */\
811 /* aggressive prefetching, while still leaving the room for segregating */\
812 /* among the distinct pages. */\
813 product(int, ContendedPaddingWidth, 128, \
814 "How many bytes to pad the fields/classes marked @Contended with")\
815 range(0, 8192) \
816 constraint(ContendedPaddingWidthConstraintFunc,AfterErgo) \
817 \
818 product(bool, EnableContended, true, \
819 "Enable @Contended annotation support") \
820 \
821 product(bool, RestrictContended, true, \
822 "Restrict @Contended to trusted classes") \
823 \
824 product(int, DiagnoseSyncOnValueBasedClasses, 0, DIAGNOSTIC, \
825 "Detect and take action upon identifying synchronization on " \
826 "value based classes. Modes: " \
827 "0: off; " \
828 "1: exit with fatal error; " \
829 "2: log message to stdout. Output file can be specified with " \
830 " -Xlog:valuebasedclasses. If JFR is running it will " \
831 " also generate JFR events.") \
832 range(0, 2) \
833 \
834 product(bool, ExitOnOutOfMemoryError, false, \
835 "JVM exits on the first occurrence of an out-of-memory error " \
836 "thrown from JVM") \
837 \
838 product(bool, CrashOnOutOfMemoryError, false, \
839 "JVM aborts, producing an error log and core/mini dump, on the " \
840 "first occurrence of an out-of-memory error thrown from JVM") \
841 \
842 product(intx, UserThreadWaitAttemptsAtExit, 30, \
843 "The number of times to wait for user threads to stop executing " \
844 "native code during JVM exit. Each wait lasts 10 milliseconds. " \
845 "The maximum number of waits is 1000, to wait at most 10 " \
846 "seconds.") \
847 range(0, 1000) \
848 \
849 /* tracing */ \
850 \
851 develop(bool, StressRewriter, false, \
852 "Stress linktime bytecode rewriting") \
853 \
854 product(ccstr, TraceJVMTI, nullptr, \
855 "Trace flags for JVMTI functions and events") \
856 \
857 product(bool, StressLdcRewrite, false, DIAGNOSTIC, \
858 "Force ldc -> ldc_w rewrite during RedefineClasses. " \
859 "This option can change an EMCP method into an obsolete method " \
860 "and can affect tests that expect specific methods to be EMCP. " \
861 "This option should be used with caution.") \
862 \
863 product(bool, AllowRedefinitionToAddDeleteMethods, false, \
864 "(Deprecated) Allow redefinition to add and delete private " \
865 "static or final methods for compatibility with old releases") \
866 \
867 develop(bool, TraceBytecodes, false, \
868 "Trace bytecode execution") \
869 \
870 develop(bool, TraceBytecodesTruncated, false, \
871 "Truncate non control-flow bytecode when tracing bytecode") \
872 \
873 develop(bool, VerifyDependencies, trueInDebug, \
874 "Exercise and verify the compilation dependency mechanism") \
875 \
876 develop(bool, TraceNewOopMapGeneration, false, \
877 "Trace OopMapGeneration") \
878 \
879 develop(bool, TraceNewOopMapGenerationDetailed, false, \
880 "Trace OopMapGeneration: print detailed cell states") \
881 \
882 develop(bool, TimeOopMap, false, \
883 "Time calls to GenerateOopMap::compute_map() in sum") \
884 \
885 develop(bool, TimeOopMap2, false, \
886 "Time calls to GenerateOopMap::compute_map() individually") \
887 \
888 develop(bool, TraceOopMapRewrites, false, \
889 "Trace rewriting of methods during oop map generation") \
890 \
891 develop(bool, TraceFinalizerRegistration, false, \
892 "Trace registration of final references") \
893 \
894 product(bool, IgnoreEmptyClassPaths, false, \
895 "Ignore empty path elements in -classpath") \
896 \
897 product(bool, PrintHeapAtSIGBREAK, true, \
898 "Print heap layout in response to SIGBREAK") \
899 \
900 product(bool, PrintClassHistogram, false, MANAGEABLE, \
901 "Print a histogram of class instances") \
902 \
903 product(double, ObjectCountCutOffPercent, 0.5, EXPERIMENTAL, \
904 "The percentage of the used heap that the instances of a class " \
905 "must occupy for the class to generate a trace event") \
906 range(0.0, 100.0) \
907 \
908 /* JVMTI heap profiling */ \
909 \
910 product(bool, VerifyBeforeIteration, false, DIAGNOSTIC, \
911 "Verify memory system before JVMTI iteration") \
912 \
913 /* compiler */ \
914 \
915 /* notice: the max range value here is max_jint, not max_intx */ \
916 /* because of overflow issue */ \
917 product(intx, CICompilerCount, CI_COMPILER_COUNT, \
918 "Number of compiler threads to run") \
919 range(0, max_jint) \
920 constraint(CICompilerCountConstraintFunc, AfterErgo) \
921 \
922 product(bool, UseDynamicNumberOfCompilerThreads, true, \
923 "Dynamically choose the number of parallel compiler threads") \
924 \
925 product(bool, ReduceNumberOfCompilerThreads, true, DIAGNOSTIC, \
926 "Reduce the number of parallel compiler threads when they " \
927 "are not used") \
928 \
929 product(bool, TraceCompilerThreads, false, DIAGNOSTIC, \
930 "Trace creation and removal of compiler threads") \
931 \
932 product(ccstr, LogClassLoadingCauseFor, nullptr, \
933 "Apply -Xlog:class+load+cause* to classes whose fully " \
934 "qualified name contains this string (\"*\" matches " \
935 "any class).") \
936 \
937 develop(bool, InjectCompilerCreationFailure, false, \
938 "Inject thread creation failures for " \
939 "UseDynamicNumberOfCompilerThreads") \
940 \
941 develop(bool, GenerateSynchronizationCode, true, \
942 "generate locking/unlocking code for synchronized methods and " \
943 "monitors") \
944 \
945 product_pd(bool, ImplicitNullChecks, DIAGNOSTIC, \
946 "Generate code for implicit null checks") \
947 \
948 product_pd(bool, TrapBasedNullChecks, \
949 "Generate code for null checks that uses a cmp and trap " \
950 "instruction raising SIGTRAP. This is only used if an access to" \
951 "null (+offset) will not raise a SIGSEGV, i.e.," \
952 "ImplicitNullChecks don't work (PPC64).") \
953 \
954 product(bool, EnableThreadSMRStatistics, trueInDebug, DIAGNOSTIC, \
955 "Enable Thread SMR Statistics") \
956 \
957 product(bool, Inline, true, \
958 "Enable inlining") \
959 \
960 product(bool, ClipInlining, true, \
961 "Clip inlining if aggregate method exceeds DesiredMethodLimit") \
962 \
963 develop(bool, UseCHA, true, \
964 "Enable CHA") \
965 \
966 product(bool, UseTypeProfile, true, \
967 "Check interpreter profile for historically monomorphic calls") \
968 \
969 product(bool, PrintInlining, false, DIAGNOSTIC, \
970 "Print inlining optimizations") \
971 \
972 product(bool, UsePopCountInstruction, false, \
973 "Use population count instruction") \
974 \
975 develop(bool, TraceMethodReplacement, false, \
976 "Print when methods are replaced do to recompilation") \
977 \
978 product(intx, MinPassesBeforeFlush, 10, DIAGNOSTIC, \
979 "Minimum number of sweeper passes before an nmethod " \
980 "can be flushed") \
981 range(0, max_intx) \
982 \
983 develop(bool, StressCodeBuffers, false, \
984 "Exercise code buffer expansion and other rare state changes") \
985 \
986 product(bool, DebugNonSafepoints, trueInDebug, DIAGNOSTIC, \
987 "Generate extra debugging information for non-safepoints in " \
988 "nmethods") \
989 \
990 product(bool, PrintVMOptions, false, \
991 "Print flags that appeared on the command line") \
992 \
993 product(bool, IgnoreUnrecognizedVMOptions, false, \
994 "Ignore unrecognized VM options") \
995 \
996 product(bool, PrintCommandLineFlags, false, \
997 "Print flags specified on command line or set by ergonomics") \
998 \
999 product(bool, PrintFlagsInitial, false, \
1000 "Print all VM flags before argument processing and exit VM") \
1001 \
1002 product(bool, PrintFlagsFinal, false, \
1003 "Print all VM flags after argument and ergonomic processing") \
1004 \
1005 develop(bool, PrintFlagsWithComments, false, \
1006 "Print all VM flags with default values and descriptions and " \
1007 "exit") \
1008 \
1009 product(bool, PrintFlagsRanges, false, \
1010 "Print VM flags and their ranges") \
1011 \
1012 product(bool, SerializeVMOutput, true, DIAGNOSTIC, \
1013 "Use a mutex to serialize output to tty and LogFile") \
1014 \
1015 product(bool, DisplayVMOutput, true, DIAGNOSTIC, \
1016 "Display all VM output on the tty, independently of LogVMOutput") \
1017 \
1018 product(bool, LogVMOutput, false, DIAGNOSTIC, \
1019 "Save VM output to LogFile") \
1020 \
1021 product(ccstr, LogFile, nullptr, DIAGNOSTIC, \
1022 "If LogVMOutput or LogCompilation is on, save VM output to " \
1023 "this file [default: ./hotspot_%p.log] (%p replaced with pidNNN)")\
1024 \
1025 product(ccstr, ErrorFile, nullptr, \
1026 "If an error occurs, save the error data to this file " \
1027 "[default: ./hs_err_%p.log] (%p replaced with pidNNN)") \
1028 \
1029 product(bool, ExtensiveErrorReports, \
1030 PRODUCT_ONLY(false) NOT_PRODUCT(true), \
1031 "Error reports are more extensive.") \
1032 \
1033 product(bool, DisplayVMOutputToStderr, false, \
1034 "If DisplayVMOutput is true, display all VM output to stderr") \
1035 \
1036 product(bool, DisplayVMOutputToStdout, false, \
1037 "If DisplayVMOutput is true, display all VM output to stdout") \
1038 \
1039 product(bool, ErrorFileToStderr, false, \
1040 "If true, error data is printed to stderr instead of a file") \
1041 \
1042 product(bool, ErrorFileToStdout, false, \
1043 "If true, error data is printed to stdout instead of a file") \
1044 \
1045 develop(bool, VerifyHeavyMonitors, false, \
1046 "Checks that no stack locking happens when using " \
1047 "-XX:LockingMode=0 (LM_MONITOR)") \
1048 \
1049 product(bool, PrintStringTableStatistics, false, \
1050 "print statistics about the StringTable and SymbolTable") \
1051 \
1052 product(bool, VerifyStringTableAtExit, false, DIAGNOSTIC, \
1053 "verify StringTable contents at exit") \
1054 \
1055 develop(bool, PrintSymbolTableSizeHistogram, false, \
1056 "print histogram of the symbol table") \
1057 \
1058 product(ccstr, AbortVMOnException, nullptr, DIAGNOSTIC, \
1059 "Call fatal if this exception is thrown. Example: " \
1060 "java -XX:AbortVMOnException=java.lang.NullPointerException Foo") \
1061 \
1062 product(ccstr, AbortVMOnExceptionMessage, nullptr, DIAGNOSTIC, \
1063 "Call fatal if the exception pointed by AbortVMOnException " \
1064 "has this message") \
1065 \
1066 develop(bool, DebugVtables, false, \
1067 "add debugging code to vtable dispatch") \
1068 \
1069 product(bool, RangeCheckElimination, true, \
1070 "Eliminate range checks") \
1071 \
1072 develop_pd(bool, UncommonNullCast, \
1073 "track occurrences of null in casts; adjust compiler tactics") \
1074 \
1075 develop(bool, TypeProfileCasts, true, \
1076 "treat casts like calls for purposes of type profiling") \
1077 \
1078 develop(bool, TraceLivenessGen, false, \
1079 "Trace the generation of liveness analysis information") \
1080 \
1081 develop(bool, TraceLivenessQuery, false, \
1082 "Trace queries of liveness analysis information") \
1083 \
1084 develop(bool, CollectIndexSetStatistics, false, \
1085 "Collect information about IndexSets") \
1086 \
1087 develop(int, FastAllocateSizeLimit, 128*K, \
1088 /* Note: This value is zero mod 1<<13 for a cheap sparc set. */ \
1089 "Inline allocations larger than this in doublewords must go slow")\
1090 \
1091 product_pd(bool, CompactStrings, \
1092 "Enable Strings to use single byte chars in backing store") \
1093 \
1094 product_pd(uint, TypeProfileLevel, \
1095 "=XYZ, with Z: Type profiling of arguments at call; " \
1096 "Y: Type profiling of return value at call; " \
1097 "X: Type profiling of parameters to methods; " \
1098 "X, Y and Z in 0=off ; 1=jsr292 only; 2=all methods") \
1099 constraint(TypeProfileLevelConstraintFunc, AfterErgo) \
1100 \
1101 product(int, TypeProfileArgsLimit, 2, \
1102 "max number of call arguments to consider for type profiling") \
1103 range(0, 16) \
1104 \
1105 product(int, TypeProfileParmsLimit, 2, \
1106 "max number of incoming parameters to consider for type profiling"\
1107 ", -1 for all") \
1108 range(-1, 64) \
1109 \
1110 /* statistics */ \
1111 develop(bool, CountCompiledCalls, false, \
1112 "Count method invocations") \
1113 \
1114 develop(bool, ICMissHistogram, false, \
1115 "Produce histogram of IC misses") \
1116 \
1117 /* interpreter */ \
1118 product_pd(bool, RewriteBytecodes, \
1119 "Allow rewriting of bytecodes (bytecodes are not immutable)") \
1120 \
1121 product_pd(bool, RewriteFrequentPairs, \
1122 "Rewrite frequently used bytecode pairs into a single bytecode") \
1123 \
1124 product(bool, PrintInterpreter, false, DIAGNOSTIC, \
1125 "Print the generated interpreter code") \
1126 \
1127 product(bool, UseInterpreter, true, \
1128 "Use interpreter for non-compiled methods") \
1129 \
1130 develop(bool, UseFastSignatureHandlers, true, \
1131 "Use fast signature handlers for native calls") \
1132 \
1133 product(bool, UseLoopCounter, true, \
1134 "Increment invocation counter on backward branch") \
1135 \
1136 product_pd(bool, UseOnStackReplacement, \
1137 "Use on stack replacement, calls runtime if invoc. counter " \
1138 "overflows in loop") \
1139 \
1140 develop(bool, TraceOnStackReplacement, false, \
1141 "Trace on stack replacement") \
1142 \
1143 product_pd(bool, PreferInterpreterNativeStubs, \
1144 "Use always interpreter stubs for native methods invoked via " \
1145 "interpreter") \
1146 \
1147 product(bool, CountBytecodes, false, DIAGNOSTIC, \
1148 "Count number of bytecodes executed") \
1149 \
1150 product(bool, CountBytecodesPerThread, false, DIAGNOSTIC, \
1151 "Count number of bytecodes executed per thread") \
1152 \
1153 product(bool, PrintBytecodeHistogram, false, DIAGNOSTIC, \
1154 "Print histogram of the executed bytecodes") \
1155 \
1156 product(double, PrintBytecodeHistogramCutoff, 0.01, \
1157 "Print cutoff for histogram of the executed bytecodes") \
1158 range(0.0, 100.0) \
1159 \
1160 develop(bool, PrintBytecodePairHistogram, false, \
1161 "Print histogram of the executed bytecode pairs") \
1162 \
1163 product(bool, PrintSignatureHandlers, false, DIAGNOSTIC, \
1164 "Print code generated for native method signature handlers") \
1165 \
1166 develop(bool, VerifyOops, false, \
1167 "Do plausibility checks for oops") \
1168 \
1169 develop(bool, CheckUnhandledOops, false, \
1170 "Check for unhandled oops in VM code") \
1171 \
1172 develop(bool, VerifyJNIFields, trueInDebug, \
1173 "Verify jfieldIDs for instance fields") \
1174 \
1175 develop(bool, VerifyFPU, false, \
1176 "Verify FPU state (check for NaN's, etc.)") \
1177 \
1178 develop(bool, VerifyActivationFrameSize, false, \
1179 "Verify that activation frame didn't become smaller than its " \
1180 "minimal size") \
1181 \
1182 develop(bool, TraceFrequencyInlining, false, \
1183 "Trace frequency based inlining") \
1184 \
1185 develop_pd(bool, InlineIntrinsics, \
1186 "Use intrinsics in Interpreter that can be statically resolved") \
1187 \
1188 product_pd(bool, ProfileInterpreter, \
1189 "Profile at the bytecode level during interpretation") \
1190 \
1191 develop_pd(bool, ProfileTraps, \
1192 "Profile deoptimization traps at the bytecode level") \
1193 \
1194 product(intx, ProfileMaturityPercentage, 20, \
1195 "number of method invocations/branches (expressed as % of " \
1196 "CompileThreshold) before using the method's profile") \
1197 range(0, 100) \
1198 \
1199 product(bool, ForceProfiling, false, DIAGNOSTIC, \
1200 "Eagerly allocate MDOs") \
1201 \
1202 product(bool, PrintMethodData, false, DIAGNOSTIC, \
1203 "Print the results of +ProfileInterpreter at end of run") \
1204 \
1205 develop(bool, VerifyDataPointer, trueInDebug, \
1206 "Verify the method data pointer during interpreter profiling") \
1207 \
1208 develop(bool, CrashGCForDumpingJavaThread, false, \
1209 "Manually make GC thread crash then dump java stack trace; " \
1210 "Test only") \
1211 \
1212 /* compilation */ \
1213 product(bool, UseCompiler, true, \
1214 "Use Just-In-Time compilation") \
1215 \
1216 product(bool, AlwaysCompileLoopMethods, false, \
1217 "When using recompilation, never interpret methods " \
1218 "containing loops") \
1219 \
1220 product(int, AllocatePrefetchStyle, 1, \
1221 "0 = no prefetch, " \
1222 "1 = generate prefetch instructions for each allocation, " \
1223 "2 = use TLAB watermark to gate allocation prefetch, " \
1224 "3 = generate one prefetch instruction per cache line") \
1225 range(0, 3) \
1226 \
1227 product(int, AllocatePrefetchDistance, -1, \
1228 "Distance to prefetch ahead of allocation pointer. " \
1229 "-1: use system-specific value (automatically determined") \
1230 range(-1, 512) \
1231 \
1232 product(int, AllocatePrefetchLines, 3, \
1233 "Number of lines to prefetch ahead of array allocation pointer") \
1234 range(1, 64) \
1235 \
1236 product(int, AllocateInstancePrefetchLines, 1, \
1237 "Number of lines to prefetch ahead of instance allocation " \
1238 "pointer") \
1239 range(1, 64) \
1240 \
1241 product(int, AllocatePrefetchStepSize, 16, \
1242 "Step size in bytes of sequential prefetch instructions") \
1243 range(1, 512) \
1244 constraint(AllocatePrefetchStepSizeConstraintFunc,AfterMemoryInit)\
1245 \
1246 product(intx, AllocatePrefetchInstr, 0, \
1247 "Select instruction to prefetch ahead of allocation pointer") \
1248 constraint(AllocatePrefetchInstrConstraintFunc, AfterMemoryInit) \
1249 \
1250 /* deoptimization */ \
1251 product(bool, TraceDeoptimization, false, DIAGNOSTIC, \
1252 "Trace deoptimization") \
1253 \
1254 develop(bool, PrintDeoptimizationDetails, false, \
1255 "Print more information about deoptimization") \
1256 \
1257 develop(bool, DebugDeoptimization, false, \
1258 "Tracing various information while debugging deoptimization") \
1259 \
1260 product(double, SelfDestructTimer, 0.0, \
1261 "Will cause VM to terminate after a given time " \
1262 "(in fractional minutes) " \
1263 "(0.0 means off)") \
1264 range(0.0, (double)max_intx) \
1265 \
1266 product(int, MaxJavaStackTraceDepth, 1024, \
1267 "The maximum number of lines in the stack trace for Java " \
1268 "exceptions (0 means all)") \
1269 range(0, max_jint/2) \
1270 \
1271 /* notice: the max range value here is max_jint, not max_intx */ \
1272 /* because of overflow issue */ \
1273 product(intx, GuaranteedSafepointInterval, 0, DIAGNOSTIC, \
1274 "Guarantee a safepoint (at least) every so many milliseconds " \
1275 "(0 means none)") \
1276 range(0, max_jint) \
1277 \
1278 product(intx, ServiceThreadCleanupInterval, 1000, DIAGNOSTIC, \
1279 "Wake the ServiceThread to do periodic cleanup checks every so " \
1280 "many milliseconds (0 means none)") \
1281 range(0, max_jint) \
1282 \
1283 product(double, SafepointTimeoutDelay, 10000, \
1284 "Delay in milliseconds for option SafepointTimeout; " \
1285 "supports sub-millisecond resolution with fractional values.") \
1286 range(0, max_jlongDouble LP64_ONLY(/MICROUNITS)) \
1287 \
1288 product(bool, UseSystemMemoryBarrier, false, \
1289 "Try to enable system memory barrier if supported by OS") \
1290 \
1291 product(intx, NmethodSweepActivity, 4, \
1292 "Removes cold nmethods from code cache if > 0. Higher values " \
1293 "result in more aggressive sweeping") \
1294 range(0, 2000) \
1295 \
1296 develop(intx, MallocCatchPtr, -1, \
1297 "Hit breakpoint when mallocing/freeing this pointer") \
1298 \
1299 develop(int, StackPrintLimit, 100, \
1300 "number of stack frames to print in VM-level stack dump") \
1301 \
1302 product(int, ErrorLogPrintCodeLimit, 3, DIAGNOSTIC, \
1303 "max number of compiled code units to print in error log") \
1304 range(0, VMError::max_error_log_print_code) \
1305 \
1306 develop(int, MaxElementPrintSize, 256, \
1307 "maximum number of elements to print") \
1308 \
1309 develop(int, MaxStringPrintSize, 256, \
1310 "maximum number of characters to print for a java.lang.String " \
1311 "in the VM. If exceeded, an abridged version of the string is " \
1312 "printed with the middle of the string elided.") \
1313 range(2, O_BUFLEN) \
1314 \
1315 develop(intx, MaxSubklassPrintSize, 4, \
1316 "maximum number of subklasses to print when printing klass") \
1317 \
1318 develop(intx, MaxForceInlineLevel, 100, \
1319 "maximum number of nested calls that are forced for inlining " \
1320 "(using CompileCommand or marked w/ @ForceInline)") \
1321 range(0, max_jint) \
1322 \
1323 develop(intx, MethodHistogramCutoff, 100, \
1324 "The cutoff value for method invocation histogram (+CountCalls)") \
1325 \
1326 develop(intx, DeoptimizeALotInterval, 5, \
1327 "Number of exits until DeoptimizeALot kicks in") \
1328 \
1329 develop(intx, ZombieALotInterval, 5, \
1330 "Number of exits until ZombieALot kicks in") \
1331 \
1332 product(ccstr, MallocLimit, nullptr, DIAGNOSTIC, \
1333 "Limit malloc allocation size from VM. Reaching a limit will " \
1334 "trigger an action (see flag). This feature requires " \
1335 "NativeMemoryTracking=summary or NativeMemoryTracking=detail." \
1336 "Usage:" \
1337 "\"-XX:MallocLimit=<size>[:<flag>]\" sets a total limit." \
1338 "\"-XX:MallocLimit=<category>:<size>[:<flag>][,<category>:<size>[:<flag>] ...]\"" \
1339 "sets one or more category-specific limits." \
1340 "<flag> defines the action upon reaching the limit:" \
1341 "\"fatal\": end VM with a fatal error at the allocation site" \
1342 "\"oom\" : will mimic a native OOM" \
1343 "If <flag> is omitted, \"fatal\" is the default." \
1344 "Examples:\n" \
1345 "-XX:MallocLimit=2g" \
1346 "-XX:MallocLimit=2g:oom" \
1347 "-XX:MallocLimit=compiler:200m:oom,code:100m") \
1348 \
1349 product(intx, TypeProfileWidth, 2, \
1350 "Number of receiver types to record in call/cast profile") \
1351 range(0, 8) \
1352 \
1353 develop(intx, BciProfileWidth, 2, \
1354 "Number of return bci's to record in ret profile") \
1355 \
1356 product(intx, PerMethodRecompilationCutoff, 400, \
1357 "After recompiling N times, stay in the interpreter (-1=>'Inf')") \
1358 range(-1, max_intx) \
1359 \
1360 product(intx, PerBytecodeRecompilationCutoff, 200, \
1361 "Per-BCI limit on repeated recompilation (-1=>'Inf')") \
1362 range(-1, max_intx) \
1363 \
1364 product(intx, PerMethodTrapLimit, 100, \
1365 "Limit on traps (of one kind) in a method (includes inlines)") \
1366 range(0, max_jint) \
1367 \
1368 product(intx, PerMethodSpecTrapLimit, 5000, EXPERIMENTAL, \
1369 "Limit on speculative traps (of one kind) in a method " \
1370 "(includes inlines)") \
1371 range(0, max_jint) \
1372 \
1373 product(intx, PerBytecodeTrapLimit, 4, \
1374 "Limit on traps (of one kind) at a particular BCI") \
1375 range(0, max_jint) \
1376 \
1377 product(int, SpecTrapLimitExtraEntries, 3, EXPERIMENTAL, \
1378 "Extra method data trap entries for speculation") \
1379 \
1380 product(double, InlineFrequencyRatio, 0.25, DIAGNOSTIC, \
1381 "Ratio of call site execution to caller method invocation") \
1382 \
1383 product(double, MinInlineFrequencyRatio, 0.0085, DIAGNOSTIC, \
1384 "Minimum ratio of call site execution to caller method" \
1385 "invocation to be considered for inlining") \
1386 \
1387 develop(intx, InlineThrowCount, 50, \
1388 "Force inlining of interpreted methods that throw this often") \
1389 range(0, max_jint) \
1390 \
1391 develop(intx, InlineThrowMaxSize, 200, \
1392 "Force inlining of throwing methods smaller than this") \
1393 range(0, max_jint) \
1394 \
1395 product(size_t, MetaspaceSize, NOT_LP64(16 * M) LP64_ONLY(21 * M), \
1396 "Initial threshold (in bytes) at which a garbage collection " \
1397 "is done to reduce Metaspace usage") \
1398 constraint(MetaspaceSizeConstraintFunc,AfterErgo) \
1399 \
1400 product(size_t, MaxMetaspaceSize, max_uintx, \
1401 "Maximum size of Metaspaces (in bytes)") \
1402 constraint(MaxMetaspaceSizeConstraintFunc,AfterErgo) \
1403 \
1404 product(size_t, CompressedClassSpaceSize, 1*G, \
1405 "Maximum size of class area in Metaspace when compressed " \
1406 "class pointers are used") \
1407 range(1*M, LP64_ONLY(4*G) NOT_LP64(max_uintx)) \
1408 \
1409 develop(size_t, CompressedClassSpaceBaseAddress, 0, \
1410 "Force the class space to be allocated at this address or " \
1411 "fails VM initialization (requires -Xshare=off.") \
1412 \
1413 develop(bool, RandomizeClassSpaceLocation, true, \
1414 "Randomize location of class space.") \
1415 \
1416 product(bool, PrintMetaspaceStatisticsAtExit, false, DIAGNOSTIC, \
1417 "Print metaspace statistics upon VM exit.") \
1418 \
1419 product(uintx, MinHeapFreeRatio, 40, MANAGEABLE, \
1420 "The minimum percentage of heap free after GC to avoid expansion."\
1421 " For most GCs this applies to the old generation. In G1 and" \
1422 " ParallelGC it applies to the whole heap.") \
1423 range(0, 100) \
1424 constraint(MinHeapFreeRatioConstraintFunc,AfterErgo) \
1425 \
1426 product(uintx, MaxHeapFreeRatio, 70, MANAGEABLE, \
1427 "The maximum percentage of heap free after GC to avoid shrinking."\
1428 " For most GCs this applies to the old generation. In G1 and" \
1429 " ParallelGC it applies to the whole heap.") \
1430 range(0, 100) \
1431 constraint(MaxHeapFreeRatioConstraintFunc,AfterErgo) \
1432 \
1433 product(intx, SoftRefLRUPolicyMSPerMB, 1000, \
1434 "Number of milliseconds per MB of free space in the heap") \
1435 range(0, max_intx) \
1436 constraint(SoftRefLRUPolicyMSPerMBConstraintFunc,AfterMemoryInit) \
1437 \
1438 product(size_t, MinHeapDeltaBytes, ScaleForWordSize(128*K), \
1439 "The minimum change in heap space due to GC (in bytes)") \
1440 range(0, max_uintx) \
1441 \
1442 product(size_t, MinMetaspaceExpansion, ScaleForWordSize(256*K), \
1443 "The minimum expansion of Metaspace (in bytes)") \
1444 range(0, max_uintx) \
1445 \
1446 product(uint, MaxMetaspaceFreeRatio, 70, \
1447 "The maximum percentage of Metaspace free after GC to avoid " \
1448 "shrinking") \
1449 range(0, 100) \
1450 constraint(MaxMetaspaceFreeRatioConstraintFunc,AfterErgo) \
1451 \
1452 product(uint, MinMetaspaceFreeRatio, 40, \
1453 "The minimum percentage of Metaspace free after GC to avoid " \
1454 "expansion") \
1455 range(0, 99) \
1456 constraint(MinMetaspaceFreeRatioConstraintFunc,AfterErgo) \
1457 \
1458 product(size_t, MaxMetaspaceExpansion, ScaleForWordSize(4*M), \
1459 "The maximum expansion of Metaspace without full GC (in bytes)") \
1460 range(0, max_uintx) \
1461 \
1462 /* stack parameters */ \
1463 product_pd(intx, StackYellowPages, \
1464 "Number of yellow zone (recoverable overflows) pages of size " \
1465 "4KB. If pages are bigger yellow zone is aligned up.") \
1466 range(MIN_STACK_YELLOW_PAGES, (DEFAULT_STACK_YELLOW_PAGES+5)) \
1467 \
1468 product_pd(intx, StackRedPages, \
1469 "Number of red zone (unrecoverable overflows) pages of size " \
1470 "4KB. If pages are bigger red zone is aligned up.") \
1471 range(MIN_STACK_RED_PAGES, (DEFAULT_STACK_RED_PAGES+2)) \
1472 \
1473 product_pd(intx, StackReservedPages, \
1474 "Number of reserved zone (reserved to annotated methods) pages" \
1475 " of size 4KB. If pages are bigger reserved zone is aligned up.") \
1476 range(MIN_STACK_RESERVED_PAGES, (DEFAULT_STACK_RESERVED_PAGES+10))\
1477 \
1478 product(bool, RestrictReservedStack, true, \
1479 "Restrict @ReservedStackAccess to trusted classes") \
1480 \
1481 /* greater stack shadow pages can't generate instruction to bang stack */ \
1482 product_pd(intx, StackShadowPages, \
1483 "Number of shadow zone (for overflow checking) pages of size " \
1484 "4KB. If pages are bigger shadow zone is aligned up. " \
1485 "This should exceed the depth of the VM and native call stack.") \
1486 range(MIN_STACK_SHADOW_PAGES, (DEFAULT_STACK_SHADOW_PAGES+30)) \
1487 \
1488 product_pd(intx, ThreadStackSize, \
1489 "Thread Stack Size (in Kbytes)") \
1490 range(0, 1 * M) \
1491 \
1492 product_pd(intx, VMThreadStackSize, \
1493 "Non-Java Thread Stack Size (in Kbytes)") \
1494 range(0, max_intx/(1 * K)) \
1495 \
1496 product_pd(intx, CompilerThreadStackSize, \
1497 "Compiler Thread Stack Size (in Kbytes)") \
1498 range(0, max_intx/(1 * K)) \
1499 \
1500 develop_pd(size_t, JVMInvokeMethodSlack, \
1501 "Stack space (bytes) required for JVM_InvokeMethod to complete") \
1502 \
1503 /* code cache parameters */ \
1504 product_pd(uintx, CodeCacheSegmentSize, EXPERIMENTAL, \
1505 "Code cache segment size (in bytes) - smallest unit of " \
1506 "allocation") \
1507 range(1, 1024) \
1508 constraint(CodeCacheSegmentSizeConstraintFunc, AfterErgo) \
1509 \
1510 product_pd(intx, CodeEntryAlignment, EXPERIMENTAL, \
1511 "Code entry alignment for generated code (in bytes)") \
1512 constraint(CodeEntryAlignmentConstraintFunc, AfterErgo) \
1513 \
1514 product_pd(intx, OptoLoopAlignment, \
1515 "Align inner loops to zero relative to this modulus") \
1516 range(1, 128) \
1517 constraint(OptoLoopAlignmentConstraintFunc, AfterErgo) \
1518 \
1519 product_pd(uintx, InitialCodeCacheSize, \
1520 "Initial code cache size (in bytes)") \
1521 constraint(VMPageSizeConstraintFunc, AtParse) \
1522 \
1523 develop_pd(uintx, CodeCacheMinimumUseSpace, \
1524 "Minimum code cache size (in bytes) required to start VM.") \
1525 range(0, max_uintx) \
1526 \
1527 product(bool, SegmentedCodeCache, false, \
1528 "Use a segmented code cache") \
1529 \
1530 product_pd(uintx, ReservedCodeCacheSize, \
1531 "Reserved code cache size (in bytes) - maximum code cache size") \
1532 constraint(VMPageSizeConstraintFunc, AtParse) \
1533 \
1534 product_pd(uintx, NonProfiledCodeHeapSize, \
1535 "Size of code heap with non-profiled methods (in bytes)") \
1536 range(0, max_uintx) \
1537 \
1538 product_pd(uintx, ProfiledCodeHeapSize, \
1539 "Size of code heap with profiled methods (in bytes)") \
1540 range(0, max_uintx) \
1541 \
1542 product_pd(uintx, NonNMethodCodeHeapSize, \
1543 "Size of code heap with non-nmethods (in bytes)") \
1544 constraint(VMPageSizeConstraintFunc, AtParse) \
1545 \
1546 product_pd(uintx, CodeCacheExpansionSize, \
1547 "Code cache expansion size (in bytes)") \
1548 range(32*K, max_uintx) \
1549 \
1550 product_pd(uintx, CodeCacheMinBlockLength, DIAGNOSTIC, \
1551 "Minimum number of segments in a code cache block") \
1552 range(1, 100) \
1553 \
1554 develop(bool, ExitOnFullCodeCache, false, \
1555 "Exit the VM if we fill the code cache") \
1556 \
1557 product(bool, UseCodeCacheFlushing, true, \
1558 "Remove cold/old nmethods from the code cache") \
1559 \
1560 product(double, SweeperThreshold, 15.0, \
1561 "Threshold when a code cache unloading GC is invoked." \
1562 "Value is percentage of ReservedCodeCacheSize.") \
1563 range(0.0, 100.0) \
1564 \
1565 product(uintx, StartAggressiveSweepingAt, 10, \
1566 "Start aggressive sweeping if X[%] of the code cache is free." \
1567 "Segmented code cache: X[%] of the non-profiled heap." \
1568 "Non-segmented code cache: X[%] of the total code cache") \
1569 range(0, 100) \
1570 \
1571 /* interpreter debugging */ \
1572 develop(intx, BinarySwitchThreshold, 5, \
1573 "Minimal number of lookupswitch entries for rewriting to binary " \
1574 "switch") \
1575 \
1576 develop(intx, StopInterpreterAt, 0, \
1577 "Stop interpreter execution at specified bytecode number") \
1578 \
1579 develop(intx, TraceBytecodesAt, 0, \
1580 "Trace bytecodes starting with specified bytecode number") \
1581 \
1582 develop(intx, TraceBytecodesStopAt, 0, \
1583 "Stop bytecode tracing at the specified bytecode number") \
1584 \
1585 /* Priorities */ \
1586 product_pd(bool, UseThreadPriorities, "Use native thread priorities") \
1587 \
1588 product(int, ThreadPriorityPolicy, 0, \
1589 "0 : Normal. "\
1590 " VM chooses priorities that are appropriate for normal "\
1591 " applications. "\
1592 " On Windows applications are allowed to use higher native "\
1593 " priorities. However, with ThreadPriorityPolicy=0, VM will "\
1594 " not use the highest possible native priority, "\
1595 " THREAD_PRIORITY_TIME_CRITICAL, as it may interfere with "\
1596 " system threads. On Linux thread priorities are ignored "\
1597 " because the OS does not support static priority in "\
1598 " SCHED_OTHER scheduling class which is the only choice for "\
1599 " non-root, non-realtime applications. "\
1600 "1 : Aggressive. "\
1601 " Java thread priorities map over to the entire range of "\
1602 " native thread priorities. Higher Java thread priorities map "\
1603 " to higher native thread priorities. This policy should be "\
1604 " used with care, as sometimes it can cause performance "\
1605 " degradation in the application and/or the entire system. On "\
1606 " Linux/BSD/macOS this policy requires root privilege or an "\
1607 " extended capability.") \
1608 range(0, 1) \
1609 \
1610 product(bool, ThreadPriorityVerbose, false, \
1611 "Print priority changes") \
1612 \
1613 product(int, CompilerThreadPriority, -1, \
1614 "The native priority at which compiler threads should run " \
1615 "(-1 means no change)") \
1616 range(min_jint, max_jint) \
1617 \
1618 product(int, VMThreadPriority, -1, \
1619 "The native priority at which the VM thread should run " \
1620 "(-1 means no change)") \
1621 range(-1, 127) \
1622 \
1623 product(int, JavaPriority1_To_OSPriority, -1, \
1624 "Map Java priorities to OS priorities") \
1625 range(-1, 127) \
1626 \
1627 product(int, JavaPriority2_To_OSPriority, -1, \
1628 "Map Java priorities to OS priorities") \
1629 range(-1, 127) \
1630 \
1631 product(int, JavaPriority3_To_OSPriority, -1, \
1632 "Map Java priorities to OS priorities") \
1633 range(-1, 127) \
1634 \
1635 product(int, JavaPriority4_To_OSPriority, -1, \
1636 "Map Java priorities to OS priorities") \
1637 range(-1, 127) \
1638 \
1639 product(int, JavaPriority5_To_OSPriority, -1, \
1640 "Map Java priorities to OS priorities") \
1641 range(-1, 127) \
1642 \
1643 product(int, JavaPriority6_To_OSPriority, -1, \
1644 "Map Java priorities to OS priorities") \
1645 range(-1, 127) \
1646 \
1647 product(int, JavaPriority7_To_OSPriority, -1, \
1648 "Map Java priorities to OS priorities") \
1649 range(-1, 127) \
1650 \
1651 product(int, JavaPriority8_To_OSPriority, -1, \
1652 "Map Java priorities to OS priorities") \
1653 range(-1, 127) \
1654 \
1655 product(int, JavaPriority9_To_OSPriority, -1, \
1656 "Map Java priorities to OS priorities") \
1657 range(-1, 127) \
1658 \
1659 product(int, JavaPriority10_To_OSPriority,-1, \
1660 "Map Java priorities to OS priorities") \
1661 range(-1, 127) \
1662 \
1663 product(bool, UseCriticalJavaThreadPriority, false, EXPERIMENTAL, \
1664 "Java thread priority 10 maps to critical scheduling priority") \
1665 \
1666 product(bool, UseCriticalCompilerThreadPriority, false, EXPERIMENTAL, \
1667 "Compiler thread(s) run at critical scheduling priority") \
1668 \
1669 develop(intx, NewCodeParameter, 0, \
1670 "Testing Only: Create a dedicated integer parameter before " \
1671 "putback") \
1672 \
1673 /* new oopmap storage allocation */ \
1674 develop(intx, MinOopMapAllocation, 8, \
1675 "Minimum number of OopMap entries in an OopMapSet") \
1676 \
1677 /* recompilation */ \
1678 product_pd(intx, CompileThreshold, \
1679 "number of interpreted method invocations before (re-)compiling") \
1680 constraint(CompileThresholdConstraintFunc, AfterErgo) \
1681 \
1682 product_pd(bool, TieredCompilation, \
1683 "Enable tiered compilation") \
1684 \
1685 /* Properties for Java libraries */ \
1686 \
1687 product(uint64_t, MaxDirectMemorySize, 0, \
1688 "Maximum total size of NIO direct-buffer allocations. " \
1689 "Ignored if not explicitly set.") \
1690 range(0, max_jlong) \
1691 \
1692 /* Flags used for temporary code during development */ \
1693 \
1694 product(bool, UseNewCode, false, DIAGNOSTIC, \
1695 "Testing Only: Use the new version while testing") \
1696 \
1697 product(bool, UseNewCode2, false, DIAGNOSTIC, \
1698 "Testing Only: Use the new version while testing") \
1699 \
1700 product(bool, UseNewCode3, false, DIAGNOSTIC, \
1701 "Testing Only: Use the new version while testing") \
1702 \
1703 develop(bool, UseDebuggerErgo, false, \
1704 "Debugging Only: Adjust the VM to be more debugger-friendly. " \
1705 "Turns on the other UseDebuggerErgo* flags") \
1706 \
1707 develop(bool, UseDebuggerErgo1, false, \
1708 "Debugging Only: Enable workarounds for debugger induced " \
1709 "os::processor_id() >= os::processor_count() problems") \
1710 \
1711 develop(bool, UseDebuggerErgo2, false, \
1712 "Debugging Only: Limit the number of spawned JVM threads") \
1713 \
1714 develop(bool, EnableJVMTIStackDepthAsserts, true, \
1715 "Enable JVMTI asserts related to stack depth checks") \
1716 \
1717 /* flags for performance data collection */ \
1718 \
1719 product(bool, UsePerfData, true, \
1720 "Flag to disable jvmstat instrumentation for performance testing "\
1721 "and problem isolation purposes") \
1722 \
1723 product(bool, PerfDataSaveToFile, false, \
1724 "Save PerfData memory to hsperfdata_<pid> file on exit") \
1725 \
1726 product(ccstr, PerfDataSaveFile, nullptr, \
1727 "Save PerfData memory to the specified absolute pathname. " \
1728 "The string %p in the file name (if present) " \
1729 "will be replaced by pid") \
1730 \
1731 product(int, PerfDataSamplingInterval, 50, \
1732 "Data sampling interval (in milliseconds)") \
1733 range(PeriodicTask::min_interval, max_jint) \
1734 constraint(PerfDataSamplingIntervalFunc, AfterErgo) \
1735 \
1736 product(bool, PerfDisableSharedMem, false, \
1737 "Store performance data in standard memory") \
1738 \
1739 product(int, PerfDataMemorySize, 64*K, \
1740 "Size of performance data memory region. Will be rounded " \
1741 "up to a multiple of the native os page size.") \
1742 range(128, 32*64*K) \
1743 \
1744 product(int, PerfMaxStringConstLength, 1024, \
1745 "Maximum PerfStringConstant string length before truncation") \
1746 range(32, 32*K) \
1747 \
1748 product(bool, PerfAllowAtExitRegistration, false, \
1749 "Allow registration of atexit() methods") \
1750 \
1751 product(bool, PerfBypassFileSystemCheck, false, \
1752 "Bypass Win32 file system criteria checks (Windows Only)") \
1753 \
1754 product(int, UnguardOnExecutionViolation, 0, \
1755 "Unguard page and retry on no-execute fault (Win32 only) " \
1756 "0=off, 1=conservative, 2=aggressive") \
1757 range(0, 2) \
1758 \
1759 /* Serviceability Support */ \
1760 \
1761 product(bool, ManagementServer, false, \
1762 "Create JMX Management Server") \
1763 \
1764 product(bool, DisableAttachMechanism, false, \
1765 "Disable mechanism that allows tools to attach to this VM") \
1766 \
1767 product(bool, StartAttachListener, false, \
1768 "Always start Attach Listener at VM startup") \
1769 \
1770 product(bool, EnableDynamicAgentLoading, true, \
1771 "Allow tools to load agents with the attach mechanism") \
1772 \
1773 product(bool, PrintConcurrentLocks, false, MANAGEABLE, \
1774 "Print java.util.concurrent locks in thread dump") \
1775 \
1776 product(bool, PrintMethodHandleStubs, false, DIAGNOSTIC, \
1777 "Print generated stub code for method handles") \
1778 \
1779 product(bool, VerifyMethodHandles, trueInDebug, DIAGNOSTIC, \
1780 "perform extra checks when constructing method handles") \
1781 \
1782 product(bool, ShowHiddenFrames, false, DIAGNOSTIC, \
1783 "show method handle implementation frames (usually hidden)") \
1784 \
1785 product(bool, ShowCarrierFrames, false, DIAGNOSTIC, \
1786 "show virtual threads' carrier frames in exceptions") \
1787 \
1788 product(bool, TrustFinalNonStaticFields, false, EXPERIMENTAL, \
1789 "trust final non-static declarations for constant folding") \
1790 \
1791 product(bool, FoldStableValues, true, DIAGNOSTIC, \
1792 "Optimize loads from stable fields (marked w/ @Stable)") \
1793 \
1794 product(int, UseBootstrapCallInfo, 1, DIAGNOSTIC, \
1795 "0: when resolving InDy or ConDy, force all BSM arguments to be " \
1796 "resolved before the bootstrap method is called; 1: when a BSM " \
1797 "that may accept a BootstrapCallInfo is detected, use that API " \
1798 "to pass BSM arguments, which allows the BSM to delay their " \
1799 "resolution; 2+: stress test the BCI API by calling more BSMs " \
1800 "via that API, instead of with the eagerly-resolved array.") \
1801 \
1802 product(bool, PauseAtStartup, false, DIAGNOSTIC, \
1803 "Causes the VM to pause at startup time and wait for the pause " \
1804 "file to be removed (default: ./vm.paused.<pid>)") \
1805 \
1806 product(ccstr, PauseAtStartupFile, nullptr, DIAGNOSTIC, \
1807 "The file to create and for whose removal to await when pausing " \
1808 "at startup. (default: ./vm.paused.<pid>)") \
1809 \
1810 product(bool, PauseAtExit, false, DIAGNOSTIC, \
1811 "Pause and wait for keypress on exit if a debugger is attached") \
1812 \
1813 product(bool, DTraceMethodProbes, false, \
1814 "Enable dtrace tool probes for method-entry and method-exit") \
1815 \
1816 product(bool, DTraceAllocProbes, false, \
1817 "Enable dtrace tool probes for object allocation") \
1818 \
1819 product(bool, DTraceMonitorProbes, false, \
1820 "Enable dtrace tool probes for monitor events") \
1821 \
1822 product(bool, RelaxAccessControlCheck, false, \
1823 "Relax the access control checks in the verifier") \
1824 \
1825 product(uintx, StringTableSize, defaultStringTableSize, \
1826 "Number of buckets in the interned String table " \
1827 "(will be rounded to nearest higher power of 2)") \
1828 range(minimumStringTableSize, 16777216ul /* 2^24 */) \
1829 \
1830 product(uintx, SymbolTableSize, defaultSymbolTableSize, EXPERIMENTAL, \
1831 "Number of buckets in the JVM internal Symbol table") \
1832 range(minimumSymbolTableSize, 16777216ul /* 2^24 */) \
1833 \
1834 product(bool, UseStringDeduplication, false, \
1835 "Use string deduplication") \
1836 \
1837 product(uint, StringDeduplicationAgeThreshold, 3, \
1838 "A string must reach this age (or be promoted to an old region) " \
1839 "to be considered for deduplication") \
1840 range(1, markWord::max_age) \
1841 \
1842 product(size_t, StringDeduplicationInitialTableSize, 500, EXPERIMENTAL, \
1843 "Approximate initial number of buckets in the table") \
1844 range(1, 1 * G) \
1845 \
1846 product(double, StringDeduplicationGrowTableLoad, 14.0, EXPERIMENTAL, \
1847 "Entries per bucket above which the table should be expanded") \
1848 range(0.1, 1000.0) \
1849 \
1850 product(double, StringDeduplicationShrinkTableLoad, 1.0, EXPERIMENTAL, \
1851 "Entries per bucket below which the table should be shrunk") \
1852 range(0.01, 100.0) \
1853 \
1854 product(double, StringDeduplicationTargetTableLoad, 7.0, EXPERIMENTAL, \
1855 "Desired entries per bucket when resizing the table") \
1856 range(0.01, 1000.0) \
1857 \
1858 product(size_t, StringDeduplicationCleanupDeadMinimum, 100, EXPERIMENTAL, \
1859 "Minimum number of dead table entries for cleaning the table") \
1860 \
1861 product(int, StringDeduplicationCleanupDeadPercent, 5, EXPERIMENTAL, \
1862 "Minimum percentage of dead table entries for cleaning the table") \
1863 range(1, 100) \
1864 \
1865 product(bool, StringDeduplicationResizeALot, false, DIAGNOSTIC, \
1866 "Force more frequent table resizing") \
1867 \
1868 product(uint64_t, StringDeduplicationHashSeed, 0, DIAGNOSTIC, \
1869 "Seed for the table hashing function; 0 requests computed seed") \
1870 \
1871 product(bool, WhiteBoxAPI, false, DIAGNOSTIC, \
1872 "Enable internal testing APIs") \
1873 \
1874 product(bool, AlwaysAtomicAccesses, false, EXPERIMENTAL, \
1875 "Accesses to all variables should always be atomic") \
1876 \
1877 product(bool, UseUnalignedAccesses, false, DIAGNOSTIC, \
1878 "Use unaligned memory accesses in Unsafe") \
1879 \
1880 product_pd(bool, PreserveFramePointer, \
1881 "Use the FP register for holding the frame pointer " \
1882 "and not as a general purpose register.") \
1883 \
1884 product(size_t, AsyncLogBufferSize, 2*M, \
1885 "Memory budget (in bytes) for the buffer of Asynchronous " \
1886 "Logging (-Xlog:async).") \
1887 range(100*K, 50*M) \
1888 \
1889 product(bool, CheckIntrinsics, true, DIAGNOSTIC, \
1890 "When a class C is loaded, check that " \
1891 "(1) all intrinsics defined by the VM for class C are present "\
1892 "in the loaded class file and are marked with the " \
1893 "@IntrinsicCandidate annotation, that " \
1894 "(2) there is an intrinsic registered for all loaded methods " \
1895 "that are annotated with the @IntrinsicCandidate annotation, " \
1896 "and that " \
1897 "(3) no orphan methods exist for class C (i.e., methods for " \
1898 "which the VM declares an intrinsic but that are not declared "\
1899 "in the loaded class C. " \
1900 "Check (3) is available only in debug builds.") \
1901 \
1902 product_pd(intx, InitArrayShortSize, DIAGNOSTIC, \
1903 "Threshold small size (in bytes) for clearing arrays. " \
1904 "Anything this size or smaller may get converted to discrete " \
1905 "scalar stores.") \
1906 range(0, max_intx) \
1907 constraint(InitArrayShortSizeConstraintFunc, AfterErgo) \
1908 \
1909 product(ccstr, AllocateHeapAt, nullptr, \
1910 "Path to the directory where a temporary file will be created " \
1911 "to use as the backing store for Java Heap.") \
1912 \
1913 product_pd(bool, VMContinuations, EXPERIMENTAL, \
1914 "Enable VM continuations support") \
1915 \
1916 develop(bool, LoomDeoptAfterThaw, false, \
1917 "Deopt stack after thaw") \
1918 \
1919 develop(bool, LoomVerifyAfterThaw, false, \
1920 "Verify stack after thaw") \
1921 \
1922 develop(bool, VerifyContinuations, false, \
1923 "Verify continuation consistency") \
1924 \
1925 develop(bool, UseContinuationFastPath, true, \
1926 "Use fast-path frame walking in continuations") \
1927 \
1928 develop(int, VerifyMetaspaceInterval, DEBUG_ONLY(500) NOT_DEBUG(0), \
1929 "Run periodic metaspace verifications (0 - none, " \
1930 "1 - always, >1 every nth interval)") \
1931 \
1932 product(bool, ShowRegistersOnAssert, true, DIAGNOSTIC, \
1933 "On internal errors, include registers in error report.") \
1934 \
1935 product(bool, UseSwitchProfiling, true, DIAGNOSTIC, \
1936 "leverage profiling for table/lookup switch") \
1937 \
1938 develop(bool, TraceMemoryWriteback, false, \
1939 "Trace memory writeback operations") \
1940 \
1941 JFR_ONLY(product(bool, FlightRecorder, false, \
1942 "(Deprecated) Enable Flight Recorder")) \
1943 \
1944 JFR_ONLY(product(ccstr, FlightRecorderOptions, nullptr, \
1945 "Flight Recorder options")) \
1946 \
1947 JFR_ONLY(product(ccstr, StartFlightRecording, nullptr, \
1948 "Start flight recording with options")) \
1949 \
1950 product(bool, UseFastUnorderedTimeStamps, false, EXPERIMENTAL, \
1951 "Use platform unstable time where supported for timestamps only") \
1952 \
1953 product(bool, DeoptimizeNMethodBarriersALot, false, DIAGNOSTIC, \
1954 "Make nmethod barriers deoptimise a lot.") \
1955 \
1956 develop(bool, VerifyCrossModifyFence, \
1957 false AARCH64_ONLY(DEBUG_ONLY(||true)), \
1958 "Mark all threads after a safepoint, and clear on a modify " \
1959 "fence. Add cleanliness checks.") \
1960 \
1961 product(int, LockingMode, LM_LIGHTWEIGHT, \
1962 "(Deprecated) Select locking mode: " \
1963 "0: (Deprecated) monitors only (LM_MONITOR), " \
1964 "1: (Deprecated) monitors & legacy stack-locking (LM_LEGACY), " \
1965 "2: monitors & new lightweight locking (LM_LIGHTWEIGHT, default)") \
1966 range(0, 2) \
1967 \
1968 product(bool, UseObjectMonitorTable, false, DIAGNOSTIC, \
1969 "With Lightweight Locking mode, use a table to record inflated " \
1970 "monitors rather than the first word of the object.") \
1971 \
1972 product(int, LightweightFastLockingSpins, 13, DIAGNOSTIC, \
1973 "Specifies the number of times lightweight fast locking will " \
1974 "attempt to CAS the markWord before inflating. Between each " \
1975 "CAS it will spin for exponentially more time, resulting in " \
1976 "a total number of spins on the order of O(2^value)") \
1977 range(1, 30) \
1978 \
1979 product(uint, TrimNativeHeapInterval, 0, \
1980 "Interval, in ms, at which the JVM will trim the native heap if " \
1981 "the platform supports that. Lower values will reclaim memory " \
1982 "more eagerly at the cost of higher overhead. A value of 0 " \
1983 "(default) disables native heap trimming.") \
1984 range(0, UINT_MAX) \
1985 \
1986 product(bool, ProfileVMLocks, false, DIAGNOSTIC, \
1987 "Profile VM locks usage on main thread") \
1988 \
1989 product(bool, ProfileVMCalls, false, DIAGNOSTIC, \
1990 "Profile VM calls on main thread") \
1991 \
1992 product(bool, ProfileVMOps, true, DIAGNOSTIC, \
1993 "Profile VM operations on main thread") \
1994 \
1995 product(bool, ProfileRuntimeCalls, false, DIAGNOSTIC, \
1996 "Profile calls into VM runtime on main thread") \
1997 \
1998 develop(bool, SimulateFullAddressSpace, false, \
1999 "Simulates a very populated, fragmented address space; no " \
2000 "targeted reservations will succeed.") \
2001 \
2002 product(bool, ProfileExceptionHandlers, true, \
2003 "Profile exception handlers") \
2004 \
2005 product(bool, AlwaysRecordEvolDependencies, true, EXPERIMENTAL, \
2006 "Unconditionally record nmethod dependencies on class " \
2007 "rewriting/transformation independently of the JVMTI " \
2008 "can_{retransform/redefine}_classes capabilities.") \
2009 \
2010 product(bool, TraceThreadTime, false, \
2011 "Enable tracing of thread time in Perf counters") \
2012 \
2013 product(bool, UseSecondarySupersCache, true, DIAGNOSTIC, \
2014 "Use secondary supers cache during subtype checks.") \
2015 \
2016 product(bool, UseSecondarySupersTable, false, DIAGNOSTIC, \
2017 "Use hash table to lookup secondary supers.") \
2018 \
2019 product(bool, VerifySecondarySupers, false, DIAGNOSTIC, \
2020 "Check that linear and hashed secondary lookups return the same result.") \
2021 \
2022 product(bool, StressSecondarySupers, false, DIAGNOSTIC, \
2023 "Use a terrible hash function in order to generate many collisions.") \
2024
2025
2026 // end of RUNTIME_FLAGS
2027
2028 DECLARE_FLAGS(LP64_RUNTIME_FLAGS)
2029 DECLARE_ARCH_FLAGS(ARCH_FLAGS)
2030 DECLARE_FLAGS(RUNTIME_FLAGS)
2031 DECLARE_FLAGS(RUNTIME_OS_FLAGS)
2032
2033 #endif // SHARE_RUNTIME_GLOBALS_HPP