1 /*
2 * Copyright (c) 1997, 2026, 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,
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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, AOTCompatibleOopCompression, false, DIAGNOSTIC, \
128 "Always use HeapBasedNarrowOop mode, so that AOT code will " \
129 "always work regardless of runtime heap range") \
130 \
131 product(bool, UseCompactObjectHeaders, true, \
132 "Use compact 64-bit object headers in 64-bit VM") \
133 \
134 product(int, ObjectAlignmentInBytes, 8, \
135 "Default object alignment in bytes, 8 is minimum") \
136 range(8, 256) \
137 constraint(ObjectAlignmentInBytesConstraintFunc, AtParse)
138
139 #else
140 // !_LP64
141
142 #define LP64_RUNTIME_FLAGS(develop, \
143 develop_pd, \
144 product, \
145 product_pd, \
146 range, \
147 constraint)
148 const bool UseCompressedOops = false;
149 const bool AOTCompatibleOopCompression = false;
150 const bool UseCompactObjectHeaders = false;
151 const int ObjectAlignmentInBytes = 8;
152
153 #endif // _LP64
154
155 // Default value for PrintAssemblyOptions, set via --with-print-assembly-options.
156 #ifndef DEFAULT_PRINT_ASSEMBLY_OPTIONS
157 #define DEFAULT_PRINT_ASSEMBLY_OPTIONS nullptr
158 #endif
159
160 #define RUNTIME_FLAGS(develop, \
161 develop_pd, \
162 product, \
163 product_pd, \
164 range, \
165 constraint) \
166 \
167 develop(bool, CheckCompressedOops, true, \
168 "Generate checks in encoding/decoding code in debug VM") \
169 \
170 product(uintx, HeapSearchSteps, 3 PPC64_ONLY(+17), \
171 "Heap allocation steps through preferred address regions to find" \
172 " where it can allocate the heap. Number of steps to take per " \
173 "region.") \
174 range(1, max_uintx) \
175 \
176 product(uint, HandshakeTimeout, 0, DIAGNOSTIC, \
177 "If nonzero set a timeout in milliseconds for handshakes") \
178 \
179 product(bool, AlwaysSafeConstructors, false, EXPERIMENTAL, \
180 "Force safe construction, as if all fields are final.") \
181 \
182 product(bool, UnlockDiagnosticVMOptions, trueInDebug, DIAGNOSTIC, \
183 "Enable normal processing of flags relating to field diagnostics")\
184 \
185 product(bool, UnlockExperimentalVMOptions, false, EXPERIMENTAL, \
186 "Enable normal processing of flags relating to experimental " \
187 "features") \
188 \
189 product(bool, JavaMonitorsInStackTrace, true, \
190 "Print information about Java monitor locks when the stacks are " \
191 "dumped") \
192 \
193 product_pd(bool, UseLargePages, \
194 "Use large page memory") \
195 \
196 product_pd(bool, UseLargePagesIndividualAllocation, \
197 "Allocate large pages individually for better affinity") \
198 \
199 develop(bool, LargePagesIndividualAllocationInjectError, false, \
200 "Fail large pages individual allocation") \
201 \
202 product(bool, UseNUMA, false, \
203 "Use NUMA if available") \
204 \
205 product(bool, UseNUMAInterleaving, false, \
206 "Interleave memory across NUMA nodes if available") \
207 \
208 product(size_t, NUMAInterleaveGranularity, 2*M, \
209 "Granularity to use for NUMA interleaving on Windows OS") \
210 constraint(NUMAInterleaveGranularityConstraintFunc, AtParse) \
211 \
212 product(bool, NUMAStats, false, \
213 "Print NUMA stats in detailed heap information") \
214 \
215 product(bool, UseAES, false, \
216 "Control whether AES instructions are used when available") \
217 \
218 product(bool, UseFMA, false, \
219 "Control whether FMA instructions are used when available") \
220 \
221 product(bool, UseSHA, false, \
222 "Control whether SHA instructions are used when available") \
223 \
224 product(bool, UseGHASHIntrinsics, false, DIAGNOSTIC, \
225 "Use intrinsics for GHASH versions of crypto") \
226 \
227 product(bool, UseBASE64Intrinsics, false, \
228 "Use intrinsics for java.util.Base64") \
229 \
230 product(bool, UsePoly1305Intrinsics, false, DIAGNOSTIC, \
231 "Use intrinsics for sun.security.util.math.intpoly") \
232 \
233 product(bool, UseIntPolyIntrinsics, false, DIAGNOSTIC, \
234 "Use intrinsics for sun.security.util.math.intpoly.MontgomeryIntegerPolynomialP256") \
235 \
236 product(bool, UseIntPoly25519Intrinsics, false, DIAGNOSTIC, \
237 "Use intrinsics for sun.security.util.math.intpoly.IntegerPolynomial25519") \
238 \
239 product(size_t, LargePageSizeInBytes, 0, \
240 "Maximum large page size used (0 will use the default large " \
241 "page size for the environment as the maximum) " \
242 "(must be a power of 2)") \
243 range(0, max_uintx) \
244 constraint(LargePageSizeInBytesConstraintFunc, AtParse) \
245 \
246 product(size_t, LargePageHeapSizeThreshold, 128*M, \
247 "Use large pages if maximum heap is at least this big") \
248 range(0, max_uintx) \
249 \
250 product(bool, ForceTimeHighResolution, false, \
251 "Using high time resolution (for Win32 only)") \
252 \
253 develop(bool, TracePcPatching, false, \
254 "Trace usage of frame::patch_pc") \
255 \
256 develop(bool, TraceRelocator, false, \
257 "Trace the bytecode relocator") \
258 \
259 \
260 product(bool, SafepointALot, false, DIAGNOSTIC, \
261 "Generate a lot of safepoints. This works with " \
262 "GuaranteedSafepointInterval") \
263 \
264 product(bool, HandshakeALot, false, DIAGNOSTIC, \
265 "Generate a lot of handshakes. This works with " \
266 "GuaranteedSafepointInterval") \
267 \
268 product_pd(bool, BackgroundCompilation, \
269 "A thread requesting compilation is not blocked during " \
270 "compilation") \
271 \
272 product(bool, MethodFlushing, true, \
273 "Reclamation of compiled methods") \
274 \
275 develop(bool, VerifyStack, false, \
276 "Verify stack of each thread when it is entering a runtime call") \
277 \
278 product(bool, ForceUnreachable, false, DIAGNOSTIC, \
279 "Make all non code cache addresses to be unreachable by " \
280 "forcing use of 64bit literal fixups") \
281 \
282 develop(bool, TraceDerivedPointers, false, \
283 "Trace traversal of derived pointers on stack") \
284 \
285 develop(bool, TraceCodeBlobStacks, false, \
286 "Trace stack-walk of codeblobs") \
287 \
288 develop(bool, PrintRewrites, false, \
289 "Print methods that are being rewritten") \
290 \
291 product(bool, UseInlineCaches, true, \
292 "Use Inline Caches for virtual calls ") \
293 \
294 develop(bool, VerifyInlineCaches, true, \
295 "Verify Inline Caches") \
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, UseKyberIntrinsics, false, DIAGNOSTIC, \
330 "Use intrinsics for the vectorized version of Kyber") \
331 \
332 product(bool, UseDilithiumIntrinsics, false, DIAGNOSTIC, \
333 "Use intrinsics for the vectorized version of Dilithium") \
334 \
335 product(bool, UseMD5Intrinsics, false, DIAGNOSTIC, \
336 "Use intrinsics for MD5 crypto hash function") \
337 \
338 product(bool, UseSHA1Intrinsics, false, DIAGNOSTIC, \
339 "Use intrinsics for SHA-1 crypto hash function. " \
340 "Requires that UseSHA is enabled.") \
341 \
342 product(bool, UseSHA256Intrinsics, false, DIAGNOSTIC, \
343 "Use intrinsics for SHA-224 and SHA-256 crypto hash functions. " \
344 "Requires that UseSHA is enabled.") \
345 \
346 product(bool, UseSHA512Intrinsics, false, DIAGNOSTIC, \
347 "Use intrinsics for SHA-384 and SHA-512 crypto hash functions. " \
348 "Requires that UseSHA is enabled.") \
349 \
350 product(bool, UseSHA3Intrinsics, false, DIAGNOSTIC, \
351 "Use intrinsics for SHA3 crypto hash function. " \
352 "Requires that UseSHA is enabled.") \
353 \
354 product(bool, UseCRC32Intrinsics, false, DIAGNOSTIC, \
355 "use intrinsics for java.util.zip.CRC32") \
356 \
357 product(bool, UseCRC32CIntrinsics, false, DIAGNOSTIC, \
358 "use intrinsics for java.util.zip.CRC32C") \
359 \
360 product(bool, UseAdler32Intrinsics, false, DIAGNOSTIC, \
361 "use intrinsics for java.util.zip.Adler32") \
362 \
363 product(bool, UseVectorizedMismatchIntrinsic, false, DIAGNOSTIC, \
364 "Enables intrinsification of ArraysSupport.vectorizedMismatch()") \
365 \
366 product(bool, UseVectorizedHashCodeIntrinsic, false, DIAGNOSTIC, \
367 "Enables intrinsification of ArraysSupport.vectorizedHashCode()") \
368 \
369 product(bool, UseCopySignIntrinsic, false, DIAGNOSTIC, \
370 "Enables intrinsification of Math.copySign") \
371 \
372 product(bool, UseSignumIntrinsic, false, DIAGNOSTIC, \
373 "Enables intrinsification of Math.signum") \
374 \
375 product_pd(bool, DelayCompilerStubsGeneration, DIAGNOSTIC, \
376 "Use Compiler thread for compiler's stubs generation") \
377 \
378 product(ccstrlist, DisableIntrinsic, "", DIAGNOSTIC, \
379 "do not expand intrinsics whose (internal) names appear here") \
380 constraint(DisableIntrinsicConstraintFunc,AfterErgo) \
381 \
382 product(ccstrlist, ControlIntrinsic, "", DIAGNOSTIC, \
383 "Control intrinsics using a list of +/- (internal) names, " \
384 "separated by commas") \
385 constraint(ControlIntrinsicConstraintFunc,AfterErgo) \
386 \
387 develop(bool, TraceCallFixup, false, \
388 "Trace all call fixups") \
389 \
390 develop(bool, DeoptimizeALot, false, \
391 "Deoptimize at every exit from the runtime system") \
392 \
393 develop(ccstrlist, DeoptimizeOnlyAt, "", \
394 "A comma separated list of bcis to deoptimize at") \
395 \
396 develop(bool, DeoptimizeRandom, false, \
397 "Deoptimize random frames on random exit from the runtime system")\
398 \
399 develop(bool, ZombieALot, false, \
400 "Create non-entrant nmethods at exit from the runtime system") \
401 \
402 develop(bool, WalkStackALot, false, \
403 "Trace stack (no print) at every exit from the runtime system") \
404 \
405 develop(bool, DeoptimizeObjectsALot, false, \
406 "For testing purposes concurrent threads revert optimizations " \
407 "based on escape analysis at intervals given with " \
408 "DeoptimizeObjectsALotInterval=n. The thread count is given " \
409 "with DeoptimizeObjectsALotThreadCountSingle and " \
410 "DeoptimizeObjectsALotThreadCountAll.") \
411 \
412 develop(uint64_t, DeoptimizeObjectsALotInterval, 5, \
413 "Interval for DeoptimizeObjectsALot.") \
414 range(0, max_jlong) \
415 \
416 develop(int, DeoptimizeObjectsALotThreadCountSingle, 1, \
417 "The number of threads that revert optimizations based on " \
418 "escape analysis for a single thread if DeoptimizeObjectsALot " \
419 "is enabled. The target thread is selected round robin." ) \
420 range(0, max_jint) \
421 \
422 develop(int, DeoptimizeObjectsALotThreadCountAll, 1, \
423 "The number of threads that revert optimizations based on " \
424 "escape analysis for all threads if DeoptimizeObjectsALot " \
425 "is enabled." ) \
426 range(0, max_jint) \
427 \
428 develop(bool, VerifyLastFrame, false, \
429 "Verify oops on last frame on entry to VM") \
430 \
431 product(bool, SafepointTimeout, false, \
432 "Time out and warn or fail after SafepointTimeoutDelay " \
433 "milliseconds if failed to reach safepoint") \
434 \
435 product(bool, AbortVMOnSafepointTimeout, false, DIAGNOSTIC, \
436 "Abort upon failure to reach safepoint (see SafepointTimeout)") \
437 \
438 product(uint64_t, AbortVMOnSafepointTimeoutDelay, 0, DIAGNOSTIC, \
439 "Delay in milliseconds for option AbortVMOnSafepointTimeout") \
440 range(0, max_jlong) \
441 \
442 product(bool, AbortVMOnVMOperationTimeout, false, DIAGNOSTIC, \
443 "Abort upon failure to complete VM operation promptly") \
444 \
445 product(intx, AbortVMOnVMOperationTimeoutDelay, 1000, DIAGNOSTIC, \
446 "Delay in milliseconds for option AbortVMOnVMOperationTimeout") \
447 range(0, max_intx) \
448 \
449 product(bool, MaxFDLimit, true, \
450 "Bump the number of file descriptors to maximum (Unix only)") \
451 \
452 product(bool, LogEvents, true, DIAGNOSTIC, \
453 "Enable the various ring buffer event logs") \
454 \
455 product(int, LogEventsBufferEntries, 20, DIAGNOSTIC, \
456 "Number of ring buffer event logs") \
457 range(1, NOT_LP64(1*K) LP64_ONLY(1*M)) \
458 \
459 product(bool, BytecodeVerificationRemote, true, DIAGNOSTIC, \
460 "Enable the Java bytecode verifier for remote classes") \
461 \
462 product(bool, BytecodeVerificationLocal, false, DIAGNOSTIC, \
463 "Enable the Java bytecode verifier for local classes") \
464 \
465 develop(bool, VerifyStackAtCalls, false, \
466 "Verify that the stack pointer is unchanged after calls") \
467 \
468 develop(bool, TraceJavaAssertions, false, \
469 "Trace java language assertions") \
470 \
471 develop(bool, VerifyCodeCache, false, \
472 "Verify code cache on memory allocation/deallocation") \
473 \
474 develop(bool, ZapResourceArea, trueInDebug, \
475 "Zap freed resource/arena space") \
476 \
477 develop(bool, ZapVMHandleArea, trueInDebug, \
478 "Zap freed VM handle space") \
479 \
480 develop(bool, ZapStackSegments, trueInDebug, \
481 "Zap allocated/freed stack segments") \
482 \
483 develop(bool, ZapUnusedHeapArea, trueInDebug, \
484 "Zap unused heap space") \
485 \
486 develop(bool, ZapFillerObjects, trueInDebug, \
487 "Zap filler objects") \
488 \
489 develop(bool, ZapCHeap, trueInDebug, \
490 "Zap allocated/freed C heap space") \
491 \
492 develop(bool, ZapTLAB, trueInDebug, \
493 "Zap allocated TLABs") \
494 develop(bool, TestingAsyncLoggingDeathTest, false, \
495 "Recursive logging death test") \
496 develop(bool, TestingAsyncLoggingDeathTestNoCrash, false, \
497 "Recursive logging death test (no crash)") \
498 \
499 product(bool, ExecutingUnitTests, false, \
500 "Whether the JVM is running unit tests or not") \
501 \
502 develop(uint, ErrorHandlerTest, 0, \
503 "If > 0, provokes an error after VM initialization; the value " \
504 "determines which error to provoke. See controlled_crash() " \
505 "in vmError.cpp.") \
506 range(0, 18) \
507 \
508 develop(uint, TestCrashInErrorHandler, 0, \
509 "If > 0, provokes an error inside VM error handler (a secondary " \
510 "crash). see controlled_crash() in vmError.cpp") \
511 range(0, 17) \
512 \
513 develop(bool, TestSafeFetchInErrorHandler, false , \
514 "If true, tests SafeFetch inside error handler.") \
515 \
516 develop(bool, TestUnresponsiveErrorHandler, false, \
517 "If true, simulates an unresponsive error handler.") \
518 \
519 develop(bool, Verbose, false, \
520 "Print additional debugging information from other modes") \
521 \
522 develop(bool, PrintMiscellaneous, false, \
523 "Print uncategorized debugging information (requires +Verbose)") \
524 \
525 develop(bool, WizardMode, false, \
526 "Print much more debugging information") \
527 \
528 product(bool, ShowMessageBoxOnError, false, \
529 "Keep process alive on VM fatal error") \
530 \
531 product(bool, CreateCoredumpOnCrash, true, \
532 "Create core/mini dump on VM fatal error") \
533 \
534 product(uint64_t, ErrorLogTimeout, 2 * 60, \
535 "Timeout, in seconds, to limit the time spent on writing an " \
536 "error log in case of a crash.") \
537 range(0, (uint64_t)max_jlong/1000) \
538 \
539 product(bool, ErrorLogSecondaryErrorDetails, false, DIAGNOSTIC, \
540 "If enabled, show details on secondary crashes in the error log") \
541 \
542 develop(intx, TraceDwarfLevel, 0, \
543 "Debug levels for the dwarf parser") \
544 range(0, 4) \
545 \
546 product(bool, SuppressFatalErrorMessage, false, \
547 "Report NO fatal error message (avoid deadlock)") \
548 \
549 product(ccstrlist, OnError, "", \
550 "Run user-defined commands on fatal error; see VMError.cpp " \
551 "for examples") \
552 \
553 product(ccstrlist, OnOutOfMemoryError, "", \
554 "Run user-defined commands on first java.lang.OutOfMemoryError " \
555 "thrown from JVM") \
556 \
557 product(bool, HeapDumpBeforeFullGC, false, MANAGEABLE, \
558 "Dump heap to file before any major stop-the-world GC " \
559 "(also see FullGCHeapDumpLimit, HeapDumpPath, HeapDumpGzipLevel)")\
560 \
561 product(bool, HeapDumpAfterFullGC, false, MANAGEABLE, \
562 "Dump heap to file after any major stop-the-world GC " \
563 "(also see FullGCHeapDumpLimit, HeapDumpPath, HeapDumpGzipLevel)")\
564 \
565 product(uint, FullGCHeapDumpLimit, 0, MANAGEABLE, \
566 "Limit the number of heap dumps triggered by " \
567 "HeapDumpBeforeFullGC or HeapDumpAfterFullGC " \
568 "(0 means no limit)") \
569 \
570 product(bool, HeapDumpOnOutOfMemoryError, false, MANAGEABLE, \
571 "Dump heap to file when java.lang.OutOfMemoryError is thrown " \
572 "from JVM " \
573 "(also see HeapDumpPath, HeapDumpGzipLevel)") \
574 \
575 product(ccstr, HeapDumpPath, nullptr, MANAGEABLE, \
576 "When HeapDumpOnOutOfMemoryError, HeapDumpBeforeFullGC " \
577 "or HeapDumpAfterFullGC is on, the path (filename or " \
578 "directory) of the dump file (defaults to java_pid<pid>.hprof " \
579 "in the working directory)") \
580 \
581 product(int, HeapDumpGzipLevel, 0, MANAGEABLE, \
582 "When HeapDumpOnOutOfMemoryError, HeapDumpBeforeFullGC " \
583 "or HeapDumpAfterFullGC is on, the gzip compression " \
584 "level of the dump file. 0 (the default) disables gzip " \
585 "compression. Otherwise the level must be between 1 and 9.") \
586 range(0, 9) \
587 \
588 product(ccstr, NativeMemoryTracking, DEBUG_ONLY("summary") NOT_DEBUG("off"), \
589 "Native memory tracking options") \
590 \
591 product(bool, PrintNMTStatistics, false, DIAGNOSTIC, \
592 "Print native memory tracking summary data if it is on") \
593 \
594 product(bool, LogCompilation, false, DIAGNOSTIC, \
595 "Log compilation activity in detail to LogFile") \
596 \
597 product(bool, PrintCompilation, false, \
598 "Print compilations") \
599 \
600 product(intx, RepeatCompilation, 0, DIAGNOSTIC, \
601 "Repeat compilation without installing code (number of times)") \
602 range(0, max_jint) \
603 \
604 product(bool, PrintExtendedThreadInfo, false, \
605 "Print more information in thread dump") \
606 \
607 product(intx, ScavengeRootsInCode, 2, DIAGNOSTIC, \
608 "0: do not allow scavengable oops in the code cache; " \
609 "1: allow scavenging from the code cache; " \
610 "2: emit as many constants as the compiler can see") \
611 range(0, 2) \
612 \
613 product(bool, AlwaysRestoreFPU, false, \
614 "Restore the FPU control word after every JNI call (expensive)") \
615 \
616 product(bool, PrintCompilation2, false, DIAGNOSTIC, \
617 "Print additional statistics per compilation") \
618 \
619 product(bool, PrintAdapterHandlers, false, DIAGNOSTIC, \
620 "Print code generated for i2c/c2i adapters") \
621 \
622 develop(bool, VerifyAdapterSharing, false, \
623 "Verify that the code for shared adapters is the equivalent") \
624 \
625 product(bool, PrintAssembly, false, DIAGNOSTIC, \
626 "Print assembly code (using external disassembler.so)") \
627 \
628 product(ccstr, PrintAssemblyOptions, DEFAULT_PRINT_ASSEMBLY_OPTIONS, \
629 DIAGNOSTIC, \
630 "Print options string passed to disassembler.so") \
631 \
632 develop(bool, PrintNMethodStatistics, false, \
633 "Print a summary statistic for the generated nmethods") \
634 \
635 product(bool, PrintNMethods, false, DIAGNOSTIC, \
636 "Print assembly code for nmethods when generated") \
637 \
638 product(bool, PrintNativeNMethods, false, DIAGNOSTIC, \
639 "Print assembly code for native nmethods when generated") \
640 \
641 develop(bool, PrintDebugInfo, false, \
642 "Print debug information for all nmethods when generated") \
643 \
644 develop(bool, PrintRelocations, false, \
645 "Print relocation information for all nmethods when generated") \
646 \
647 develop(bool, PrintDependencies, false, \
648 "Print dependency information for all nmethods when generated") \
649 \
650 develop(bool, PrintExceptionHandlers, false, \
651 "Print exception handler tables for all nmethods when generated") \
652 \
653 develop(bool, StressCompiledExceptionHandlers, false, \
654 "Exercise compiled exception handlers") \
655 \
656 product(bool, DeoptimizeOnAllocationException, false, DIAGNOSTIC, \
657 "Deoptimize on exception during allocation instead of using the " \
658 "compiled exception handlers") \
659 \
660 develop(bool, InterceptOSException, false, \
661 "Start debugger when an implicit OS (e.g. null pointer) " \
662 "exception happens") \
663 \
664 product(bool, PrintCodeCache, false, \
665 "Print the code cache memory usage when exiting") \
666 \
667 develop(bool, PrintCodeCache2, false, \
668 "Print detailed usage information on the code cache when exiting")\
669 \
670 product(bool, PrintCodeCacheOnCompilation, false, \
671 "Print the code cache memory usage each time a method is " \
672 "compiled") \
673 \
674 product(bool, PrintCodeHeapAnalytics, false, DIAGNOSTIC, \
675 "Print code heap usage statistics on exit and on full condition") \
676 \
677 product(bool, PrintStubCode, false, DIAGNOSTIC, \
678 "Print generated stub code") \
679 \
680 product(bool, StackTraceInThrowable, true, \
681 "Collect backtrace in throwable when exception happens") \
682 \
683 product(bool, OmitStackTraceInFastThrow, true, \
684 "Omit backtraces for some 'hot' exceptions in optimized code") \
685 \
686 product(bool, ShowCodeDetailsInExceptionMessages, true, MANAGEABLE, \
687 "Show exception messages from RuntimeExceptions that contain " \
688 "snippets of the failing code. Disable this to improve privacy.") \
689 \
690 product(bool, PrintWarnings, true, \
691 "Print JVM warnings to output stream") \
692 \
693 develop(bool, RegisterReferences, true, \
694 "Tell whether the VM should register soft/weak/final/phantom " \
695 "references") \
696 \
697 develop(bool, PrintCodeCacheExtension, false, \
698 "Print extension of code cache") \
699 \
700 product(bool, ClassUnloading, true, \
701 "Do unloading of classes") \
702 \
703 product(bool, ClassUnloadingWithConcurrentMark, true, \
704 "Do unloading of classes with a concurrent marking cycle") \
705 \
706 develop(bool, PrintSystemDictionaryAtExit, false, \
707 "Print the system dictionary at exit") \
708 \
709 develop(bool, PrintClassLoaderDataGraphAtExit, false, \
710 "Print the class loader data graph at exit") \
711 \
712 product(bool, PrintVMInfoAtExit, false, DIAGNOSTIC, \
713 "Executes the VM.info diagnostic command at exit") \
714 \
715 product(bool, AllowParallelDefineClass, false, \
716 "Allow parallel defineClass requests for class loaders " \
717 "registering as parallel capable") \
718 \
719 product(bool, DisablePrimordialThreadGuardPages, false, EXPERIMENTAL, \
720 "Disable the use of stack guard pages if the JVM is loaded " \
721 "on the primordial process thread") \
722 \
723 product(bool, DoJVMTIVirtualThreadTransitions, true, EXPERIMENTAL, \
724 "Do JVMTI virtual thread mount/unmount transitions " \
725 "(disabling this flag implies no JVMTI events are posted)") \
726 \
727 /* notice: the max range value here is max_jint, not max_intx */ \
728 /* because of overflow issue */ \
729 product(intx, AsyncDeflationInterval, 250, DIAGNOSTIC, \
730 "Async deflate idle monitors every so many milliseconds when " \
731 "MonitorUsedDeflationThreshold is exceeded (0 is off).") \
732 range(0, max_jint) \
733 \
734 /* notice: the max range value here is max_jint, not max_intx */ \
735 /* because of overflow issue */ \
736 product(intx, GuaranteedAsyncDeflationInterval, 60000, DIAGNOSTIC, \
737 "Async deflate idle monitors every so many milliseconds even " \
738 "when MonitorUsedDeflationThreshold is NOT exceeded (0 is off).") \
739 range(0, max_jint) \
740 \
741 product(size_t, AvgMonitorsPerThreadEstimate, 1024, DIAGNOSTIC, \
742 "Used to estimate a variable ceiling based on number of threads " \
743 "for use with MonitorUsedDeflationThreshold (0 is off).") \
744 range(0, max_uintx) \
745 \
746 /* notice: the max range value here is max_jint, not max_intx */ \
747 /* because of overflow issue */ \
748 product(intx, MonitorDeflationMax, 1000000, DIAGNOSTIC, \
749 "The maximum number of monitors to deflate, unlink and delete " \
750 "at one time (minimum is 1024).") \
751 range(1024, max_jint) \
752 \
753 product(intx, MonitorUnlinkBatch, 500, DIAGNOSTIC, \
754 "The maximum number of monitors to unlink in one batch. ") \
755 range(1, max_jint) \
756 \
757 product(int, MonitorUsedDeflationThreshold, 90, DIAGNOSTIC, \
758 "Percentage of used monitors before triggering deflation (0 is " \
759 "off). The check is performed on AsyncDeflationInterval or " \
760 "GuaranteedAsyncDeflationInterval, whichever is lower.") \
761 range(0, 100) \
762 \
763 product(uintx, NoAsyncDeflationProgressMax, 3, DIAGNOSTIC, \
764 "Max number of no progress async deflation attempts to tolerate " \
765 "before adjusting the in_use_list_ceiling up (0 is off).") \
766 range(0, max_uintx) \
767 \
768 product(intx, hashCode, 5, EXPERIMENTAL, \
769 "(Unstable) select hashCode generation algorithm") \
770 \
771 product(bool, ReduceSignalUsage, false, \
772 "Reduce the use of OS signals in Java and/or the VM") \
773 \
774 develop(bool, LoadLineNumberTables, true, \
775 "Tell whether the class file parser loads line number tables") \
776 \
777 develop(bool, LoadLocalVariableTables, true, \
778 "Tell whether the class file parser loads local variable tables") \
779 \
780 develop(bool, LoadLocalVariableTypeTables, true, \
781 "Tell whether the class file parser loads local variable type" \
782 "tables") \
783 \
784 product(bool, AllowUserSignalHandlers, false, \
785 "Application will install primary signal handlers for the JVM " \
786 "(Unix only)") \
787 \
788 product(bool, UseSignalChaining, true, \
789 "Use signal-chaining to invoke signal handlers installed " \
790 "by the application (Unix only)") \
791 \
792 product(bool, RestoreMXCSROnJNICalls, false, \
793 "Restore MXCSR when returning from JNI calls") \
794 \
795 product(bool, CheckJNICalls, false, \
796 "Verify all arguments to JNI calls") \
797 \
798 product(bool, UseFastJNIAccessors, true, \
799 "Use optimized versions of Get<Primitive>Field") \
800 \
801 product(intx, MaxJNILocalCapacity, 65536, \
802 "Maximum allowable local JNI handle capacity to " \
803 "EnsureLocalCapacity() and PushLocalFrame(), " \
804 "where <= 0 is unlimited, default: 65536") \
805 range(min_intx, max_intx) \
806 \
807 product(bool, EagerXrunInit, false, \
808 "Eagerly initialize -Xrun libraries; allows startup profiling, " \
809 "but not all -Xrun libraries may support the state of the VM " \
810 "at this time") \
811 \
812 develop(uintx, PreallocatedOutOfMemoryErrorCount, 4, \
813 "Number of OutOfMemoryErrors preallocated with backtrace") \
814 range(0, 1024) \
815 \
816 product(bool, PrintFieldLayout, false, DIAGNOSTIC, \
817 "Print field layout for each class") \
818 \
819 product(bool, PrintInlineLayout, false, DIAGNOSTIC, \
820 "Print field layout for each value class or class containing " \
821 "inlined value fields") \
822 \
823 product(bool, PrintFlatArrayLayout, false, DIAGNOSTIC, \
824 "Print array layout for each flattened value array") \
825 \
826 product(bool, UseArrayFlattening, true, DIAGNOSTIC, \
827 "Allow the JVM to flatten arrays of concrete value objects " \
828 "when it determines it is possible and beneficial to do so") \
829 \
830 product(bool, UseFieldFlattening, true, DIAGNOSTIC, \
831 "Allow the JVM to inline the fields of concrete value objects " \
832 "when it determines it is possible and beneficial to do so") \
833 \
834 product(bool, UseNullableAtomicValueFlattening, true, DIAGNOSTIC, \
835 "Allow the JVM to flatten some nullable atomic values") \
836 \
837 product(bool, UseNullFreeNonAtomicValueFlattening, true, EXPERIMENTAL, \
838 "Allow the JVM to flatten some null-free non-atomic values") \
839 \
840 product(bool, UseNullFreeAtomicValueFlattening, true, EXPERIMENTAL, \
841 "Allow the JVM to flatten some null-free atomic values") \
842 \
843 product(bool, UseNullableNonAtomicValueFlattening, true, DIAGNOSTIC, \
844 "Allow the JVM to flatten some strict final non-static fields") \
845 \
846 product(intx, FlatArrayElementMaxOops, 4, DIAGNOSTIC, \
847 "Max number of embedded object references in a value container " \
848 "before no flattening attempts are made, <0 indicates no limit") \
849 \
850 product(uint, FlatteningBudget, 1024, EXPERIMENTAL, \
851 "Maximum size (in bytes) dedicated to flat fields in an instance")\
852 range(0, 1024 * 1024) \
853 develop(ccstrlist, PrintInlineKlassFields, "", \
854 "Print fields collected by InlineKlass::collect_fields") \
855 \
856 /* Need to limit the extent of the padding to reasonable size. */\
857 /* 8K is well beyond the reasonable HW cache line size, even with */\
858 /* aggressive prefetching, while still leaving the room for segregating */\
859 /* among the distinct pages. */\
860 product(int, ContendedPaddingWidth, 128, \
861 "How many bytes to pad the fields/classes marked @Contended with")\
862 range(0, 8192) \
863 constraint(ContendedPaddingWidthConstraintFunc,AfterErgo) \
864 \
865 product(bool, EnableContended, true, \
866 "Enable @Contended annotation support") \
867 \
868 product(bool, RestrictContended, true, \
869 "Restrict @Contended to trusted classes") \
870 \
871 product(int, DiagnoseSyncOnValueBasedClasses, 0, DIAGNOSTIC, \
872 "Detect and take action upon identifying synchronization on " \
873 "value based classes. Modes: " \
874 "0: off; " \
875 "1: exit with fatal error; " \
876 "2: log message to stdout. Output file can be specified with " \
877 " -Xlog:valuebasedclasses. If JFR is running it will " \
878 " also generate JFR events.") \
879 range(0, 2) \
880 \
881 product(bool, ExitOnOutOfMemoryError, false, \
882 "JVM exits on the first occurrence of an out-of-memory error " \
883 "thrown from JVM") \
884 \
885 product(bool, CrashOnOutOfMemoryError, false, \
886 "JVM aborts, producing an error log and core/mini dump, on the " \
887 "first occurrence of an out-of-memory error thrown from JVM") \
888 \
889 product(intx, UserThreadWaitAttemptsAtExit, 30, \
890 "The number of times to wait for user threads to stop executing " \
891 "native code during JVM exit. Each wait lasts 10 milliseconds. " \
892 "The maximum number of waits is 1000, to wait at most 10 " \
893 "seconds.") \
894 range(0, 1000) \
895 \
896 /* tracing */ \
897 \
898 develop(bool, StressRewriter, false, \
899 "Stress linktime bytecode rewriting") \
900 \
901 product(ccstr, TraceJVMTI, nullptr, \
902 "Trace flags for JVMTI functions and events") \
903 \
904 product(bool, StressLdcRewrite, false, DIAGNOSTIC, \
905 "Force ldc -> ldc_w rewrite during RedefineClasses. " \
906 "This option can change an EMCP method into an obsolete method " \
907 "and can affect tests that expect specific methods to be EMCP. " \
908 "This option should be used with caution.") \
909 \
910 product(bool, AllowRedefinitionToAddDeleteMethods, false, \
911 "(Deprecated) Allow redefinition to add and delete private " \
912 "static or final methods for compatibility with old releases") \
913 \
914 develop(bool, TraceBytecodes, false, \
915 "Trace bytecode execution") \
916 \
917 develop(bool, TraceBytecodesTruncated, false, \
918 "Truncate non control-flow bytecode when tracing bytecode") \
919 \
920 develop(bool, VerifyDependencies, trueInDebug, \
921 "Exercise and verify the compilation dependency mechanism") \
922 \
923 develop(bool, TimeOopMap, false, \
924 "Time calls to GenerateOopMap::compute_map() in sum") \
925 \
926 develop(bool, GenerateOopMapALot, false, \
927 "Generate interpreter oopmaps at all safepoints") \
928 \
929 develop(bool, TraceFinalizerRegistration, false, \
930 "Trace registration of final references") \
931 \
932 product(bool, IgnoreEmptyClassPaths, false, \
933 "Ignore empty path elements in -classpath") \
934 \
935 product(bool, PrintHeapAtSIGBREAK, true, \
936 "Print heap layout in response to SIGBREAK") \
937 \
938 product(bool, PrintClassHistogram, false, MANAGEABLE, \
939 "Print a histogram of class instances") \
940 \
941 product(double, ObjectCountCutOffPercent, 0.5, EXPERIMENTAL, \
942 "The percentage of the used heap that the instances of a class " \
943 "must occupy for the class to generate a trace event") \
944 range(0.0, 100.0) \
945 \
946 /* JVMTI heap profiling */ \
947 \
948 product(bool, VerifyBeforeIteration, false, DIAGNOSTIC, \
949 "Verify memory system before JVMTI iteration") \
950 \
951 /* compiler */ \
952 \
953 /* notice: the max range value here is max_jint, not max_intx */ \
954 /* because of overflow issue */ \
955 product(intx, CICompilerCount, CI_COMPILER_COUNT, \
956 "Number of compiler threads to run") \
957 range(0, max_jint) \
958 constraint(CICompilerCountConstraintFunc, AfterErgo) \
959 \
960 product(bool, UseDynamicNumberOfCompilerThreads, true, \
961 "Dynamically choose the number of parallel compiler threads") \
962 \
963 product(bool, ReduceNumberOfCompilerThreads, true, DIAGNOSTIC, \
964 "Reduce the number of parallel compiler threads when they " \
965 "are not used") \
966 \
967 product(bool, TraceCompilerThreads, false, DIAGNOSTIC, \
968 "Trace creation and removal of compiler threads") \
969 \
970 product(ccstr, LogClassLoadingCauseFor, nullptr, \
971 "Apply -Xlog:class+load+cause* to classes whose fully " \
972 "qualified name contains this string (\"*\" matches " \
973 "any class).") \
974 \
975 develop(bool, InjectCompilerCreationFailure, false, \
976 "Inject thread creation failures for " \
977 "UseDynamicNumberOfCompilerThreads") \
978 \
979 product_pd(bool, ImplicitNullChecks, DIAGNOSTIC, \
980 "Generate code for implicit null checks") \
981 \
982 product_pd(bool, TrapBasedNullChecks, \
983 "Generate code for null checks that uses a cmp and trap " \
984 "instruction raising SIGTRAP. This is only used if an access to" \
985 "null (+offset) will not raise a SIGSEGV, i.e.," \
986 "ImplicitNullChecks don't work (PPC64).") \
987 \
988 product(bool, EnableThreadSMRStatistics, trueInDebug, DIAGNOSTIC, \
989 "Enable Thread SMR Statistics") \
990 \
991 product(bool, Inline, true, \
992 "Enable inlining") \
993 \
994 product(bool, ClipInlining, true, \
995 "Clip inlining if aggregate method exceeds DesiredMethodLimit") \
996 \
997 develop(bool, UseCHA, true, \
998 "Enable CHA") \
999 \
1000 product(bool, UseTypeProfile, true, \
1001 "Check interpreter profile for historically monomorphic calls") \
1002 \
1003 product(bool, PrintInlining, false, DIAGNOSTIC, \
1004 "Print inlining optimizations") \
1005 \
1006 product(bool, UsePopCountInstruction, false, \
1007 "Use population count instruction") \
1008 \
1009 develop(bool, TraceMethodReplacement, false, \
1010 "Print when methods are replaced do to recompilation") \
1011 \
1012 product(intx, MinPassesBeforeFlush, 10, DIAGNOSTIC, \
1013 "Minimum number of sweeper passes before an nmethod " \
1014 "can be flushed") \
1015 range(0, max_intx) \
1016 \
1017 develop(bool, StressCodeBuffers, false, \
1018 "Exercise code buffer expansion and other rare state changes") \
1019 \
1020 product(bool, DebugNonSafepoints, trueInDebug, DIAGNOSTIC, \
1021 "Generate extra debugging information for non-safepoints in " \
1022 "nmethods") \
1023 \
1024 product(bool, PrintVMOptions, false, \
1025 "Print flags that appeared on the command line") \
1026 \
1027 product(bool, IgnoreUnrecognizedVMOptions, false, \
1028 "Ignore unrecognized VM options") \
1029 \
1030 product(bool, PrintCommandLineFlags, false, \
1031 "Print flags specified on command line or set by ergonomics") \
1032 \
1033 product(bool, PrintFlagsInitial, false, \
1034 "Print all VM flags before argument processing and exit VM") \
1035 \
1036 product(bool, PrintFlagsFinal, false, \
1037 "Print all VM flags after argument and ergonomic processing") \
1038 \
1039 develop(bool, PrintFlagsWithComments, false, \
1040 "Print all VM flags with default values and descriptions and " \
1041 "exit") \
1042 \
1043 product(bool, PrintFlagsRanges, false, \
1044 "Print VM flags and their ranges") \
1045 \
1046 product(bool, SerializeVMOutput, true, DIAGNOSTIC, \
1047 "Use a mutex to serialize output to tty and LogFile") \
1048 \
1049 product(bool, DisplayVMOutput, true, DIAGNOSTIC, \
1050 "Display all VM output on the tty, independently of LogVMOutput") \
1051 \
1052 product(bool, LogVMOutput, false, DIAGNOSTIC, \
1053 "Save VM output to LogFile") \
1054 \
1055 product(ccstr, LogFile, nullptr, DIAGNOSTIC, \
1056 "If LogVMOutput or LogCompilation is on, save VM output to " \
1057 "this file [default: ./hotspot_pid%p.log] (%p replaced with pid)")\
1058 \
1059 product(ccstr, ErrorFile, nullptr, \
1060 "If an error occurs, save the error data to this file " \
1061 "[default: ./hs_err_pid%p.log] (%p replaced with pid)") \
1062 \
1063 product(bool, ExtensiveErrorReports, \
1064 PRODUCT_ONLY(false) NOT_PRODUCT(true), \
1065 "Error reports are more extensive.") \
1066 \
1067 product(bool, DisplayVMOutputToStderr, false, \
1068 "If DisplayVMOutput is true, display all VM output to stderr") \
1069 \
1070 product(bool, DisplayVMOutputToStdout, false, \
1071 "If DisplayVMOutput is true, display all VM output to stdout") \
1072 \
1073 product(bool, ErrorFileToStderr, false, \
1074 "If true, error data is printed to stderr instead of a file") \
1075 \
1076 product(bool, ErrorFileToStdout, false, \
1077 "If true, error data is printed to stdout instead of a file") \
1078 \
1079 product(bool, PrintStringTableStatistics, false, \
1080 "print statistics about the StringTable and SymbolTable") \
1081 \
1082 product(bool, VerifyStringTableAtExit, false, DIAGNOSTIC, \
1083 "verify StringTable contents at exit") \
1084 \
1085 develop(bool, PrintSymbolTableSizeHistogram, false, \
1086 "print histogram of the symbol table") \
1087 \
1088 product(ccstr, AbortVMOnException, nullptr, DIAGNOSTIC, \
1089 "Call fatal if this exception is thrown. Example: " \
1090 "java -XX:AbortVMOnException=java.lang.NullPointerException Foo") \
1091 \
1092 product(ccstr, AbortVMOnExceptionMessage, nullptr, DIAGNOSTIC, \
1093 "Call fatal if the exception pointed by AbortVMOnException " \
1094 "has this message") \
1095 \
1096 develop(bool, DebugVtables, false, \
1097 "add debugging code to vtable dispatch") \
1098 \
1099 product(bool, RangeCheckElimination, true, \
1100 "Eliminate range checks") \
1101 \
1102 develop_pd(bool, UncommonNullCast, \
1103 "track occurrences of null in casts; adjust compiler tactics") \
1104 \
1105 develop(bool, TypeProfileCasts, true, \
1106 "treat casts like calls for purposes of type profiling") \
1107 \
1108 develop(bool, TraceLivenessGen, false, \
1109 "Trace the generation of liveness analysis information") \
1110 \
1111 develop(bool, TraceLivenessQuery, false, \
1112 "Trace queries of liveness analysis information") \
1113 \
1114 develop(bool, CollectIndexSetStatistics, false, \
1115 "Collect information about IndexSets") \
1116 \
1117 /* This value is later shifted left by up to LogBytesPerLong bits */\
1118 /* (to convert from element count to size in bytes), so we must ensure */\
1119 /* it does not overflow during the shift. */\
1120 develop(int, FastAllocateSizeLimit, 128*K, \
1121 /* Note: This value is zero mod 1<<13 for a cheap sparc set. */ \
1122 "Inline allocations larger than this in doublewords must go slow")\
1123 range(0, (1 << (BitsPerInt - LogBytesPerLong - 1)) - 1) \
1124 \
1125 product_pd(bool, CompactStrings, \
1126 "Enable Strings to use single byte chars in backing store") \
1127 \
1128 product_pd(uint, TypeProfileLevel, \
1129 "=XYZ, with Z: Type profiling of arguments at call; " \
1130 "Y: Type profiling of return value at call; " \
1131 "X: Type profiling of parameters to methods; " \
1132 "X, Y and Z in 0=off ; 1=jsr292 only; 2=all methods") \
1133 constraint(TypeProfileLevelConstraintFunc, AfterErgo) \
1134 \
1135 product(int, TypeProfileArgsLimit, 2, \
1136 "max number of call arguments to consider for type profiling") \
1137 range(0, 16) \
1138 \
1139 product(int, TypeProfileParmsLimit, 2, \
1140 "max number of incoming parameters to consider for type profiling"\
1141 ", -1 for all") \
1142 range(-1, 64) \
1143 \
1144 /* statistics */ \
1145 develop(bool, CountCompiledCalls, false, \
1146 "Count method invocations") \
1147 \
1148 develop(bool, ICMissHistogram, false, \
1149 "Produce histogram of IC misses") \
1150 \
1151 /* interpreter */ \
1152 product_pd(bool, RewriteBytecodes, \
1153 "Allow rewriting of bytecodes (bytecodes are not immutable)") \
1154 \
1155 product_pd(bool, RewriteFrequentPairs, \
1156 "Rewrite frequently used bytecode pairs into a single bytecode") \
1157 \
1158 product(bool, PrintInterpreter, false, DIAGNOSTIC, \
1159 "Print the generated interpreter code") \
1160 \
1161 product(bool, UseInterpreter, true, \
1162 "Use interpreter for non-compiled methods") \
1163 \
1164 develop(bool, UseFastSignatureHandlers, true, \
1165 "Use fast signature handlers for native calls") \
1166 \
1167 product(bool, UseLoopCounter, true, \
1168 "Increment invocation counter on backward branch") \
1169 \
1170 product_pd(bool, UseOnStackReplacement, \
1171 "Use on stack replacement, calls runtime if invoc. counter " \
1172 "overflows in loop") \
1173 \
1174 develop(bool, TraceOnStackReplacement, false, \
1175 "Trace on stack replacement") \
1176 \
1177 product_pd(bool, PreferInterpreterNativeStubs, \
1178 "Use always interpreter stubs for native methods invoked via " \
1179 "interpreter") \
1180 \
1181 develop(bool, CountBytecodes, false, \
1182 "Count number of bytecodes executed") \
1183 \
1184 develop(bool, PrintBytecodeHistogram, false, \
1185 "Print histogram of the executed bytecodes") \
1186 \
1187 develop(bool, PrintBytecodePairHistogram, false, \
1188 "Print histogram of the executed bytecode pairs") \
1189 \
1190 product(bool, PrintSignatureHandlers, false, DIAGNOSTIC, \
1191 "Print code generated for native method signature handlers") \
1192 \
1193 develop(bool, VerifyOops, false, \
1194 "Do plausibility checks for oops") \
1195 \
1196 develop(bool, CheckUnhandledOops, false, \
1197 "Check for unhandled oops in VM code") \
1198 \
1199 develop(bool, VerifyJNIFields, trueInDebug, \
1200 "Verify jfieldIDs for instance fields") \
1201 \
1202 develop(bool, VerifyActivationFrameSize, false, \
1203 "Verify that activation frame didn't become smaller than its " \
1204 "minimal size") \
1205 \
1206 develop(bool, TraceFrequencyInlining, false, \
1207 "Trace frequency based inlining") \
1208 \
1209 develop_pd(bool, InlineIntrinsics, \
1210 "Use intrinsics in Interpreter that can be statically resolved") \
1211 \
1212 product_pd(bool, ProfileInterpreter, \
1213 "Profile at the bytecode level during interpretation") \
1214 \
1215 develop_pd(bool, ProfileTraps, \
1216 "Profile deoptimization traps at the bytecode level") \
1217 \
1218 product(intx, ProfileMaturityPercentage, 20, \
1219 "number of method invocations/branches (expressed as % of " \
1220 "CompileThreshold) before using the method's profile") \
1221 range(0, 100) \
1222 \
1223 product(bool, PrintMethodData, false, DIAGNOSTIC, \
1224 "Print the results of +ProfileInterpreter at end of run") \
1225 \
1226 develop(bool, VerifyDataPointer, trueInDebug, \
1227 "Verify the method data pointer during interpreter profiling") \
1228 \
1229 develop(bool, CrashGCForDumpingJavaThread, false, \
1230 "Manually make GC thread crash then dump java stack trace; " \
1231 "Test only") \
1232 \
1233 /* compilation */ \
1234 product(bool, UseCompiler, true, \
1235 "Use Just-In-Time compilation") \
1236 \
1237 product(bool, AlwaysCompileLoopMethods, false, \
1238 "(Deprecated) When using recompilation, never interpret methods " \
1239 "containing loops") \
1240 \
1241 product(int, AllocatePrefetchStyle, 1, \
1242 "0 = no prefetch, " \
1243 "1 = generate prefetch instructions for each allocation, " \
1244 "2 = use TLAB watermark to gate allocation prefetch, " \
1245 "3 = generate one prefetch instruction per cache line") \
1246 range(0, 3) \
1247 \
1248 product(int, AllocatePrefetchDistance, -1, \
1249 "Distance to prefetch ahead of allocation pointer. " \
1250 "-1: use system-specific value (automatically determined") \
1251 range(-1, 512) \
1252 \
1253 product(int, AllocatePrefetchLines, 3, \
1254 "Number of lines to prefetch ahead of array allocation pointer") \
1255 range(1, 64) \
1256 \
1257 product(int, AllocateInstancePrefetchLines, 1, \
1258 "Number of lines to prefetch ahead of instance allocation " \
1259 "pointer") \
1260 range(1, 64) \
1261 \
1262 product(int, AllocatePrefetchStepSize, 16, \
1263 "Step size in bytes of sequential prefetch instructions") \
1264 range(1, 512) \
1265 constraint(AllocatePrefetchStepSizeConstraintFunc,AfterMemoryInit)\
1266 \
1267 product(intx, AllocatePrefetchInstr, 0, \
1268 "Select instruction to prefetch ahead of allocation pointer") \
1269 constraint(AllocatePrefetchInstrConstraintFunc, AfterMemoryInit) \
1270 \
1271 /* deoptimization */ \
1272 product(bool, TraceDeoptimization, false, DIAGNOSTIC, \
1273 "Trace deoptimization") \
1274 \
1275 develop(bool, PrintDeoptimizationDetails, false, \
1276 "Print more information about deoptimization") \
1277 \
1278 develop(bool, DebugDeoptimization, false, \
1279 "Tracing various information while debugging deoptimization") \
1280 \
1281 product(double, SelfDestructTimer, 0.0, \
1282 "Will cause VM to terminate after a given time " \
1283 "(in fractional minutes) " \
1284 "(0.0 means off)") \
1285 range(0.0, (double)max_intx) \
1286 \
1287 product(int, MaxJavaStackTraceDepth, 1024, \
1288 "The maximum number of lines in the stack trace for Java " \
1289 "exceptions (0 means all)") \
1290 range(0, max_jint/2) \
1291 \
1292 /* notice: the max range value here is max_jint, not max_intx */ \
1293 /* because of overflow issue */ \
1294 product(intx, GuaranteedSafepointInterval, 0, DIAGNOSTIC, \
1295 "Guarantee a safepoint (at least) every so many milliseconds " \
1296 "(0 means none)") \
1297 range(0, max_jint) \
1298 \
1299 product(intx, ServiceThreadCleanupInterval, 1000, DIAGNOSTIC, \
1300 "Wake the ServiceThread to do periodic cleanup checks every so " \
1301 "many milliseconds (0 means none)") \
1302 range(0, max_jint) \
1303 \
1304 product(double, SafepointTimeoutDelay, 10000, \
1305 "Delay in milliseconds for option SafepointTimeout; " \
1306 "supports sub-millisecond resolution with fractional values.") \
1307 range(0, max_jlongDouble LP64_ONLY(/MICROUNITS)) \
1308 \
1309 product(bool, UseSystemMemoryBarrier, false, \
1310 "Try to enable system memory barrier if supported by OS") \
1311 \
1312 product(intx, NmethodSweepActivity, 4, \
1313 "Removes cold nmethods from code cache if > 0. Higher values " \
1314 "result in more aggressive sweeping") \
1315 range(0, 2000) \
1316 \
1317 develop(intx, MallocCatchPtr, -1, \
1318 "Hit breakpoint when mallocing/freeing this pointer") \
1319 \
1320 develop(int, StackPrintLimit, 100, \
1321 "number of stack frames to print in VM-level stack dump") \
1322 \
1323 product(int, ErrorLogPrintCodeLimit, 3, DIAGNOSTIC, \
1324 "max number of compiled code units to print in error log") \
1325 range(0, VMError::max_error_log_print_code) \
1326 \
1327 develop(int, MaxElementPrintSize, 256, \
1328 "maximum number of elements to print") \
1329 \
1330 develop(int, MaxStringPrintSize, 256, \
1331 "maximum number of characters to print for a java.lang.String " \
1332 "in the VM. If exceeded, an abridged version of the string is " \
1333 "printed with the middle of the string elided.") \
1334 range(2, O_BUFLEN) \
1335 \
1336 develop(intx, MaxSubklassPrintSize, 4, \
1337 "maximum number of subklasses to print when printing klass") \
1338 \
1339 develop(intx, MaxForceInlineLevel, 100, \
1340 "maximum number of nested calls that are forced for inlining " \
1341 "(using CompileCommand or marked w/ @ForceInline)") \
1342 range(0, max_jint) \
1343 \
1344 develop(intx, MethodHistogramCutoff, 100, \
1345 "The cutoff value for method invocation histogram (+CountCalls)") \
1346 \
1347 develop(intx, DeoptimizeALotInterval, 5, \
1348 "Number of exits until DeoptimizeALot kicks in") \
1349 \
1350 develop(intx, ZombieALotInterval, 5, \
1351 "Number of exits until ZombieALot kicks in") \
1352 \
1353 product(ccstr, MallocLimit, nullptr, DIAGNOSTIC, \
1354 "Limit malloc allocation size from VM. Reaching a limit will " \
1355 "trigger an action (see flag). This feature requires " \
1356 "NativeMemoryTracking=summary or NativeMemoryTracking=detail." \
1357 "Usage:" \
1358 "\"-XX:MallocLimit=<size>[:<flag>]\" sets a total limit." \
1359 "\"-XX:MallocLimit=<category>:<size>[:<flag>][,<category>:<size>[:<flag>] ...]\"" \
1360 "sets one or more category-specific limits." \
1361 "<flag> defines the action upon reaching the limit:" \
1362 "\"fatal\": end VM with a fatal error at the allocation site" \
1363 "\"oom\" : will mimic a native OOM" \
1364 "If <flag> is omitted, \"fatal\" is the default." \
1365 "Examples:\n" \
1366 "-XX:MallocLimit=2g" \
1367 "-XX:MallocLimit=2g:oom" \
1368 "-XX:MallocLimit=compiler:200m:oom,code:100m") \
1369 \
1370 product(intx, TypeProfileWidth, 2, \
1371 "Number of receiver types to record in call/cast profile") \
1372 range(0, 8) \
1373 \
1374 develop(intx, BciProfileWidth, 2, \
1375 "Number of return bci's to record in ret profile") \
1376 \
1377 product(intx, PerMethodRecompilationCutoff, 400, \
1378 "After recompiling N times, stay in the interpreter (-1=>'Inf')") \
1379 range(-1, max_intx) \
1380 \
1381 product(intx, PerBytecodeRecompilationCutoff, 200, \
1382 "Per-BCI limit on repeated recompilation (-1=>'Inf')") \
1383 range(-1, max_intx) \
1384 \
1385 product(intx, PerMethodTrapLimit, 100, \
1386 "Limit on traps (of one kind) in a method (includes inlines)") \
1387 range(0, max_jint) \
1388 \
1389 product(intx, PerMethodSpecTrapLimit, 5000, EXPERIMENTAL, \
1390 "Limit on speculative traps (of one kind) in a method " \
1391 "(includes inlines)") \
1392 range(0, max_jint) \
1393 \
1394 product(intx, PerBytecodeTrapLimit, 4, \
1395 "Limit on traps (of one kind) at a particular BCI") \
1396 range(0, max_jint) \
1397 \
1398 product(int, SpecTrapLimitExtraEntries, 3, EXPERIMENTAL, \
1399 "Extra method data trap entries for speculation") \
1400 range(0, 100) \
1401 \
1402 product(double, InlineFrequencyRatio, 0.25, DIAGNOSTIC, \
1403 "Ratio of call site execution to caller method invocation") \
1404 \
1405 product(double, MinInlineFrequencyRatio, 0.0085, DIAGNOSTIC, \
1406 "Minimum ratio of call site execution to caller method" \
1407 "invocation to be considered for inlining") \
1408 \
1409 develop(intx, InlineThrowCount, 50, \
1410 "Force inlining of interpreted methods that throw this often") \
1411 range(0, max_jint) \
1412 \
1413 develop(intx, InlineThrowMaxSize, 200, \
1414 "Force inlining of throwing methods smaller than this") \
1415 range(0, max_jint) \
1416 \
1417 product(size_t, MetaspaceSize, NOT_LP64(16 * M) LP64_ONLY(21 * M), \
1418 "Initial threshold (in bytes) at which a garbage collection " \
1419 "is done to reduce Metaspace usage") \
1420 constraint(MetaspaceSizeConstraintFunc,AfterErgo) \
1421 \
1422 product(size_t, MaxMetaspaceSize, max_uintx, \
1423 "Maximum size of Metaspaces (in bytes)") \
1424 constraint(MaxMetaspaceSizeConstraintFunc,AfterErgo) \
1425 \
1426 product(size_t, CompressedClassSpaceSize, 1*G, \
1427 "Maximum size of class area in Metaspace when compressed " \
1428 "class pointers are used") \
1429 range(1*M, LP64_ONLY(4*G) NOT_LP64(max_uintx)) \
1430 \
1431 develop(size_t, CompressedClassSpaceBaseAddress, 0, \
1432 "Force the class space to be allocated at this address or " \
1433 "fails VM initialization (requires -Xshare=off.") \
1434 \
1435 develop(bool, RandomizeClassSpaceLocation, true, \
1436 "Randomize location of class space.") \
1437 \
1438 product(bool, PrintMetaspaceStatisticsAtExit, false, DIAGNOSTIC, \
1439 "Print metaspace statistics upon VM exit.") \
1440 \
1441 product(bool, PrintCompilerMemoryStatisticsAtExit, false, DIAGNOSTIC, \
1442 "Print compiler memory statistics upon VM exit.") \
1443 \
1444 product(uintx, MinHeapFreeRatio, 40, MANAGEABLE, \
1445 "The minimum percentage of heap free after GC to avoid expansion."\
1446 " For most GCs this applies to the old generation. In G1 and" \
1447 " ParallelGC it applies to the whole heap.") \
1448 range(0, 100) \
1449 constraint(MinHeapFreeRatioConstraintFunc,AfterErgo) \
1450 \
1451 product(uintx, MaxHeapFreeRatio, 70, MANAGEABLE, \
1452 "The maximum percentage of heap free after GC to avoid shrinking."\
1453 " For most GCs this applies to the old generation. In G1 and" \
1454 " ParallelGC it applies to the whole heap.") \
1455 range(0, 100) \
1456 constraint(MaxHeapFreeRatioConstraintFunc,AfterErgo) \
1457 \
1458 product(intx, SoftRefLRUPolicyMSPerMB, 1000, \
1459 "Number of milliseconds per MB of free space in the heap") \
1460 range(0, max_intx) \
1461 constraint(SoftRefLRUPolicyMSPerMBConstraintFunc,AfterMemoryInit) \
1462 \
1463 product(size_t, MinHeapDeltaBytes, ScaleForWordSize(128*K), \
1464 "The minimum change in heap space due to GC (in bytes)") \
1465 range(0, max_uintx / 2 + 1) \
1466 \
1467 product(size_t, MinMetaspaceExpansion, ScaleForWordSize(256*K), \
1468 "The minimum expansion of Metaspace (in bytes)") \
1469 range(0, max_uintx) \
1470 \
1471 product(uint, MaxMetaspaceFreeRatio, 70, \
1472 "The maximum percentage of Metaspace free after GC to avoid " \
1473 "shrinking") \
1474 range(0, 100) \
1475 constraint(MaxMetaspaceFreeRatioConstraintFunc,AfterErgo) \
1476 \
1477 product(uint, MinMetaspaceFreeRatio, 40, \
1478 "The minimum percentage of Metaspace free after GC to avoid " \
1479 "expansion") \
1480 range(0, 99) \
1481 constraint(MinMetaspaceFreeRatioConstraintFunc,AfterErgo) \
1482 \
1483 product(size_t, MaxMetaspaceExpansion, ScaleForWordSize(4*M), \
1484 "The maximum expansion of Metaspace without full GC (in bytes)") \
1485 range(0, max_uintx) \
1486 \
1487 /* stack parameters */ \
1488 product_pd(intx, StackYellowPages, \
1489 "Number of yellow zone (recoverable overflows) pages of size " \
1490 "4KB. If pages are bigger yellow zone is aligned up.") \
1491 range(MIN_STACK_YELLOW_PAGES, (DEFAULT_STACK_YELLOW_PAGES+5)) \
1492 \
1493 product_pd(intx, StackRedPages, \
1494 "Number of red zone (unrecoverable overflows) pages of size " \
1495 "4KB. If pages are bigger red zone is aligned up.") \
1496 range(MIN_STACK_RED_PAGES, (DEFAULT_STACK_RED_PAGES+2)) \
1497 \
1498 product_pd(intx, StackReservedPages, \
1499 "Number of reserved zone (reserved to annotated methods) pages" \
1500 " of size 4KB. If pages are bigger reserved zone is aligned up.") \
1501 range(MIN_STACK_RESERVED_PAGES, (DEFAULT_STACK_RESERVED_PAGES+10))\
1502 \
1503 product(bool, RestrictReservedStack, true, \
1504 "Restrict @ReservedStackAccess to trusted classes") \
1505 \
1506 /* greater stack shadow pages can't generate instruction to bang stack */ \
1507 product_pd(intx, StackShadowPages, \
1508 "Number of shadow zone (for overflow checking) pages of size " \
1509 "4KB. If pages are bigger shadow zone is aligned up. " \
1510 "This should exceed the depth of the VM and native call stack.") \
1511 range(MIN_STACK_SHADOW_PAGES, (DEFAULT_STACK_SHADOW_PAGES+30)) \
1512 \
1513 product_pd(intx, ThreadStackSize, \
1514 "Thread Stack Size (in Kbytes)") \
1515 range(0, 1 * M) \
1516 \
1517 product_pd(intx, VMThreadStackSize, \
1518 "Non-Java Thread Stack Size (in Kbytes)") \
1519 range(0, max_intx/(1 * K)) \
1520 \
1521 product_pd(intx, CompilerThreadStackSize, \
1522 "Compiler Thread Stack Size (in Kbytes)") \
1523 range(0, max_intx/(1 * K)) \
1524 \
1525 develop_pd(size_t, JVMInvokeMethodSlack, \
1526 "Stack space (bytes) required for JVM_InvokeMethod to complete") \
1527 \
1528 /* code cache parameters */ \
1529 product_pd(size_t, CodeCacheSegmentSize, EXPERIMENTAL, \
1530 "Code cache segment size (in bytes) - smallest unit of " \
1531 "allocation") \
1532 range(1, 1024) \
1533 constraint(CodeCacheSegmentSizeConstraintFunc, AfterErgo) \
1534 \
1535 product_pd(uint, CodeEntryAlignment, EXPERIMENTAL, \
1536 "Code entry alignment for generated code" \
1537 " (in bytes, power of two)") \
1538 constraint(CodeEntryAlignmentConstraintFunc, AfterErgo) \
1539 \
1540 product_pd(intx, OptoLoopAlignment, \
1541 "Align inner loops to zero relative to this modulus") \
1542 range(1, 128) \
1543 constraint(OptoLoopAlignmentConstraintFunc, AfterErgo) \
1544 \
1545 product_pd(size_t, InitialCodeCacheSize, \
1546 "Initial code cache size (in bytes)") \
1547 constraint(VMPageSizeConstraintFunc, AtParse) \
1548 \
1549 develop_pd(size_t, CodeCacheMinimumUseSpace, \
1550 "Minimum code cache size (in bytes) required to start VM.") \
1551 range(0, SIZE_MAX) \
1552 \
1553 product(bool, SegmentedCodeCache, false, \
1554 "Use a segmented code cache") \
1555 \
1556 product_pd(size_t, ReservedCodeCacheSize, \
1557 "Reserved code cache size (in bytes) - maximum code cache size") \
1558 constraint(VMPageSizeConstraintFunc, AtParse) \
1559 \
1560 product_pd(size_t, NonProfiledCodeHeapSize, \
1561 "Size of code heap with non-profiled methods (in bytes)") \
1562 range(0, SIZE_MAX) \
1563 \
1564 product_pd(size_t, ProfiledCodeHeapSize, \
1565 "Size of code heap with profiled methods (in bytes)") \
1566 range(0, SIZE_MAX) \
1567 \
1568 product_pd(size_t, NonNMethodCodeHeapSize, \
1569 "Size of code heap with non-nmethods (in bytes)") \
1570 constraint(VMPageSizeConstraintFunc, AtParse) \
1571 \
1572 product(size_t, HotCodeHeapSize, 0, EXPERIMENTAL, \
1573 "Size of code heap with predicted hot methods (in bytes)") \
1574 range(0, SIZE_MAX) \
1575 \
1576 product_pd(size_t, CodeCacheExpansionSize, \
1577 "Code cache expansion size (in bytes)") \
1578 range(32*K, SIZE_MAX) \
1579 \
1580 product_pd(size_t, CodeCacheMinBlockLength, DIAGNOSTIC, \
1581 "Minimum number of segments in a code cache block") \
1582 range(1, 100) \
1583 \
1584 develop(bool, ExitOnFullCodeCache, false, \
1585 "Exit the VM if we fill the code cache") \
1586 \
1587 product(bool, UseCodeCacheFlushing, true, \
1588 "Remove cold/old nmethods from the code cache") \
1589 \
1590 product(double, SweeperThreshold, 15.0, \
1591 "Threshold when a code cache unloading GC is invoked." \
1592 "Value is percentage of ReservedCodeCacheSize.") \
1593 range(0.0, 100.0) \
1594 \
1595 product(uintx, StartAggressiveSweepingAt, 10, \
1596 "Start aggressive sweeping if less than X[%] of the total code cache is free.")\
1597 range(0, 100) \
1598 \
1599 product(bool, NMethodRelocation, false, EXPERIMENTAL, \
1600 "Enables use of experimental function nmethod::relocate()") \
1601 \
1602 /* interpreter debugging */ \
1603 develop(intx, BinarySwitchThreshold, 5, \
1604 "Minimal number of lookupswitch entries for rewriting to binary " \
1605 "switch") \
1606 \
1607 develop(uintx, StopInterpreterAt, 0, \
1608 "Stop interpreter execution at specified bytecode number") \
1609 \
1610 develop(uintx, TraceBytecodesAt, 0, \
1611 "Trace bytecodes starting with specified bytecode number") \
1612 \
1613 develop(uintx, TraceBytecodesStopAt, 0, \
1614 "Stop bytecode tracing at the specified bytecode number") \
1615 \
1616 /* Priorities */ \
1617 product_pd(bool, UseThreadPriorities, "Use native thread priorities") \
1618 \
1619 product(int, ThreadPriorityPolicy, 0, \
1620 "0 : Normal. "\
1621 " VM chooses priorities that are appropriate for normal "\
1622 " applications. "\
1623 " On Windows applications are allowed to use higher native "\
1624 " priorities. However, with ThreadPriorityPolicy=0, VM will "\
1625 " not use the highest possible native priority, "\
1626 " THREAD_PRIORITY_TIME_CRITICAL, as it may interfere with "\
1627 " system threads. On Linux thread priorities are ignored "\
1628 " because the OS does not support static priority in "\
1629 " SCHED_OTHER scheduling class which is the only choice for "\
1630 " non-root, non-realtime applications. "\
1631 "1 : Aggressive. "\
1632 " Java thread priorities map over to the entire range of "\
1633 " native thread priorities. Higher Java thread priorities map "\
1634 " to higher native thread priorities. This policy should be "\
1635 " used with care, as sometimes it can cause performance "\
1636 " degradation in the application and/or the entire system. On "\
1637 " Linux/BSD/macOS this policy requires root privilege or an "\
1638 " extended capability.") \
1639 range(0, 1) \
1640 \
1641 product(bool, ThreadPriorityVerbose, false, \
1642 "Print priority changes") \
1643 \
1644 product(int, CompilerThreadPriority, -1, \
1645 "The native priority at which compiler threads should run " \
1646 "(-1 means no change)") \
1647 range(min_jint, max_jint) \
1648 \
1649 product(int, VMThreadPriority, -1, \
1650 "The native priority at which the VM thread should run " \
1651 "(-1 means no change)") \
1652 range(min_jint, max_jint) \
1653 \
1654 product(int, JavaPriority1_To_OSPriority, -1, \
1655 "Map Java priorities to OS priorities") \
1656 range(min_jint, max_jint) \
1657 \
1658 product(int, JavaPriority2_To_OSPriority, -1, \
1659 "Map Java priorities to OS priorities") \
1660 range(min_jint, max_jint) \
1661 \
1662 product(int, JavaPriority3_To_OSPriority, -1, \
1663 "Map Java priorities to OS priorities") \
1664 range(min_jint, max_jint) \
1665 \
1666 product(int, JavaPriority4_To_OSPriority, -1, \
1667 "Map Java priorities to OS priorities") \
1668 range(min_jint, max_jint) \
1669 \
1670 product(int, JavaPriority5_To_OSPriority, -1, \
1671 "Map Java priorities to OS priorities") \
1672 range(min_jint, max_jint) \
1673 \
1674 product(int, JavaPriority6_To_OSPriority, -1, \
1675 "Map Java priorities to OS priorities") \
1676 range(min_jint, max_jint) \
1677 \
1678 product(int, JavaPriority7_To_OSPriority, -1, \
1679 "Map Java priorities to OS priorities") \
1680 range(min_jint, max_jint) \
1681 \
1682 product(int, JavaPriority8_To_OSPriority, -1, \
1683 "Map Java priorities to OS priorities") \
1684 range(min_jint, max_jint) \
1685 \
1686 product(int, JavaPriority9_To_OSPriority, -1, \
1687 "Map Java priorities to OS priorities") \
1688 range(min_jint, max_jint) \
1689 \
1690 product(int, JavaPriority10_To_OSPriority,-1, \
1691 "Map Java priorities to OS priorities") \
1692 range(min_jint, max_jint) \
1693 \
1694 product(bool, UseCriticalJavaThreadPriority, false, EXPERIMENTAL, \
1695 "Java thread priority 10 maps to critical scheduling priority") \
1696 \
1697 product(bool, UseCriticalCompilerThreadPriority, false, EXPERIMENTAL, \
1698 "Compiler thread(s) run at critical scheduling priority") \
1699 \
1700 develop(intx, NewCodeParameter, 0, \
1701 "Testing Only: Create a dedicated integer parameter before " \
1702 "putback") \
1703 \
1704 /* new oopmap storage allocation */ \
1705 develop(int, MinOopMapAllocation, 8, \
1706 "Minimum number of OopMap entries in an OopMapSet") \
1707 range(0, max_jint) \
1708 \
1709 /* recompilation */ \
1710 product_pd(intx, CompileThreshold, \
1711 "number of interpreted method invocations before (re-)compiling") \
1712 constraint(CompileThresholdConstraintFunc, AfterErgo) \
1713 \
1714 product_pd(bool, TieredCompilation, \
1715 "Enable tiered compilation") \
1716 \
1717 /* Properties for Java libraries */ \
1718 \
1719 product(uint64_t, MaxDirectMemorySize, 0, \
1720 "Maximum total size of NIO direct-buffer allocations. " \
1721 "Ignored if not explicitly set.") \
1722 range(0, max_jlong) \
1723 \
1724 /* Flags used for temporary code during development */ \
1725 \
1726 product(bool, UseNewCode, false, DIAGNOSTIC, \
1727 "Testing Only: Use the new version while testing") \
1728 \
1729 product(bool, UseNewCode2, false, DIAGNOSTIC, \
1730 "Testing Only: Use the new version while testing") \
1731 \
1732 product(bool, UseNewCode3, false, DIAGNOSTIC, \
1733 "Testing Only: Use the new version while testing") \
1734 \
1735 develop(bool, UseDebuggerErgo, false, \
1736 "Debugging Only: Adjust the VM to be more debugger-friendly. " \
1737 "Turns on the other UseDebuggerErgo* flags") \
1738 \
1739 develop(bool, UseDebuggerErgo1, false, \
1740 "Debugging Only: Enable workarounds for debugger induced " \
1741 "os::processor_id() >= os::processor_count() problems") \
1742 \
1743 develop(bool, UseDebuggerErgo2, false, \
1744 "Debugging Only: Limit the number of spawned JVM threads") \
1745 \
1746 develop(bool, EnableJVMTIStackDepthAsserts, true, \
1747 "Enable JVMTI asserts related to stack depth checks") \
1748 \
1749 /* flags for performance data collection */ \
1750 \
1751 product(bool, UsePerfData, true, \
1752 "Flag to disable jvmstat instrumentation for performance testing "\
1753 "and problem isolation purposes") \
1754 \
1755 product(bool, PerfDataSaveToFile, false, \
1756 "Save PerfData memory to hsperfdata_<pid> file on exit") \
1757 \
1758 product(ccstr, PerfDataSaveFile, nullptr, \
1759 "Save PerfData memory to the specified absolute pathname. " \
1760 "The string %p in the file name (if present) " \
1761 "will be replaced by pid") \
1762 \
1763 product(bool, PerfDisableSharedMem, false, \
1764 "Store performance data in standard memory") \
1765 \
1766 product(int, PerfDataMemorySize, 32*K, \
1767 "Size of performance data memory region. Will be rounded " \
1768 "up to a multiple of the native os page size.") \
1769 range(128, 32*64*K) \
1770 \
1771 product(int, PerfMaxStringConstLength, 1024, \
1772 "Maximum PerfStringConstant string length before truncation") \
1773 range(32, 32*K) \
1774 \
1775 product(bool, PerfAllowAtExitRegistration, false, \
1776 "Allow registration of atexit() methods") \
1777 \
1778 product(bool, PerfBypassFileSystemCheck, false, \
1779 "Bypass Win32 file system criteria checks (Windows Only)") \
1780 \
1781 product(int, UnguardOnExecutionViolation, 0, \
1782 "Unguard page and retry on no-execute fault (Win32 only) " \
1783 "0=off, 1=conservative, 2=aggressive") \
1784 range(0, 2) \
1785 \
1786 /* Serviceability Support */ \
1787 \
1788 product(bool, ManagementServer, false, \
1789 "Create JMX Management Server") \
1790 \
1791 product(bool, DisableAttachMechanism, false, \
1792 "Disable mechanism that allows tools to attach to this VM") \
1793 \
1794 product(bool, StartAttachListener, false, \
1795 "Always start Attach Listener at VM startup") \
1796 \
1797 product(bool, EnableDynamicAgentLoading, true, \
1798 "Allow tools to load agents with the attach mechanism") \
1799 \
1800 product(bool, PrintConcurrentLocks, false, MANAGEABLE, \
1801 "Print java.util.concurrent locks in thread dump") \
1802 \
1803 product(bool, PrintMethodHandleStubs, false, DIAGNOSTIC, \
1804 "Print generated stub code for method handles") \
1805 \
1806 product(bool, VerifyMethodHandles, trueInDebug, DIAGNOSTIC, \
1807 "perform extra checks when constructing method handles") \
1808 \
1809 product(bool, IgnoreAssertUnsetFields, false, DIAGNOSTIC, \
1810 "Ignore assert_unset_fields") \
1811 \
1812 product(bool, ShowHiddenFrames, false, DIAGNOSTIC, \
1813 "show method handle implementation frames (usually hidden)") \
1814 \
1815 product(bool, ShowCarrierFrames, false, DIAGNOSTIC, \
1816 "show virtual threads' carrier frames in exceptions") \
1817 \
1818 product(bool, TrustFinalNonStaticFields, false, EXPERIMENTAL, \
1819 "trust final non-static declarations for constant folding") \
1820 \
1821 product(bool, FoldStableValues, true, DIAGNOSTIC, \
1822 "Optimize loads from stable fields (marked w/ @Stable)") \
1823 \
1824 product(int, UseBootstrapCallInfo, 1, DIAGNOSTIC, \
1825 "0: when resolving InDy or ConDy, force all BSM arguments to be " \
1826 "resolved before the bootstrap method is called; 1: when a BSM " \
1827 "that may accept a BootstrapCallInfo is detected, use that API " \
1828 "to pass BSM arguments, which allows the BSM to delay their " \
1829 "resolution; 2+: stress test the BCI API by calling more BSMs " \
1830 "via that API, instead of with the eagerly-resolved array.") \
1831 \
1832 product(bool, PauseAtStartup, false, DIAGNOSTIC, \
1833 "Causes the VM to pause at startup time and wait for the pause " \
1834 "file to be removed (default: ./vm.paused.<pid>)") \
1835 \
1836 product(ccstr, PauseAtStartupFile, nullptr, DIAGNOSTIC, \
1837 "The file to create and for whose removal to await when pausing " \
1838 "at startup. (default: ./vm.paused.<pid>)") \
1839 \
1840 product(bool, PauseAtExit, false, DIAGNOSTIC, \
1841 "Pause and wait for keypress on exit if a debugger is attached") \
1842 \
1843 product(bool, DTraceMethodProbes, false, \
1844 "Enable dtrace tool probes for method-entry and method-exit") \
1845 \
1846 product(bool, DTraceAllocProbes, false, \
1847 "Enable dtrace tool probes for object allocation") \
1848 \
1849 product(bool, DTraceMonitorProbes, false, \
1850 "Enable dtrace tool probes for monitor events") \
1851 \
1852 product(bool, RelaxAccessControlCheck, false, \
1853 "Relax the access control checks in the verifier") \
1854 \
1855 product(uintx, StringTableSize, defaultStringTableSize, \
1856 "Number of buckets in the interned String table " \
1857 "(will be rounded to nearest higher power of 2)") \
1858 range(minimumStringTableSize, 16777216ul /* 2^24 */) \
1859 \
1860 product(uintx, SymbolTableSize, defaultSymbolTableSize, EXPERIMENTAL, \
1861 "Number of buckets in the JVM internal Symbol table") \
1862 range(minimumSymbolTableSize, 16777216ul /* 2^24 */) \
1863 \
1864 product(bool, UseStringDeduplication, false, \
1865 "Use string deduplication") \
1866 \
1867 product(uint, StringDeduplicationAgeThreshold, 3, \
1868 "A string must reach this age (or be promoted to an old region) " \
1869 "to be considered for deduplication") \
1870 range(1, markWord::max_age) \
1871 \
1872 product(size_t, StringDeduplicationInitialTableSize, 500, EXPERIMENTAL, \
1873 "Approximate initial number of buckets in the table") \
1874 range(1, 1 * G) \
1875 \
1876 product(double, StringDeduplicationGrowTableLoad, 14.0, EXPERIMENTAL, \
1877 "Entries per bucket above which the table should be expanded") \
1878 range(0.1, 1000.0) \
1879 \
1880 product(double, StringDeduplicationShrinkTableLoad, 1.0, EXPERIMENTAL, \
1881 "Entries per bucket below which the table should be shrunk") \
1882 range(0.01, 100.0) \
1883 \
1884 product(double, StringDeduplicationTargetTableLoad, 7.0, EXPERIMENTAL, \
1885 "Desired entries per bucket when resizing the table") \
1886 range(0.01, 1000.0) \
1887 \
1888 product(size_t, StringDeduplicationCleanupDeadMinimum, 100, EXPERIMENTAL, \
1889 "Minimum number of dead table entries for cleaning the table") \
1890 \
1891 product(int, StringDeduplicationCleanupDeadPercent, 5, EXPERIMENTAL, \
1892 "Minimum percentage of dead table entries for cleaning the table") \
1893 range(1, 100) \
1894 \
1895 product(bool, StringDeduplicationResizeALot, false, DIAGNOSTIC, \
1896 "Force more frequent table resizing") \
1897 \
1898 product(uint64_t, StringDeduplicationHashSeed, 0, DIAGNOSTIC, \
1899 "Seed for the table hashing function; 0 requests computed seed") \
1900 \
1901 product(bool, WhiteBoxAPI, false, DIAGNOSTIC, \
1902 "Enable internal testing APIs") \
1903 \
1904 product(bool, UseUnalignedAccesses, false, DIAGNOSTIC, \
1905 "Use unaligned memory accesses in Unsafe") \
1906 \
1907 product_pd(bool, PreserveFramePointer, \
1908 "Use the FP register for holding the frame pointer " \
1909 "and not as a general purpose register.") \
1910 \
1911 product(size_t, AsyncLogBufferSize, 2*M, \
1912 "Memory budget (in bytes) for the buffer of Asynchronous " \
1913 "Logging (-Xlog:async).") \
1914 range(DEBUG_ONLY(192) NOT_DEBUG(100*K), 50*M) \
1915 \
1916 product(bool, CheckIntrinsics, true, DIAGNOSTIC, \
1917 "When a class C is loaded, check that " \
1918 "(1) all intrinsics defined by the VM for class C are present "\
1919 "in the loaded class file and are marked with the " \
1920 "@IntrinsicCandidate annotation, that " \
1921 "(2) there is an intrinsic registered for all loaded methods " \
1922 "that are annotated with the @IntrinsicCandidate annotation, " \
1923 "and that " \
1924 "(3) no orphan methods exist for class C (i.e., methods for " \
1925 "which the VM declares an intrinsic but that are not declared "\
1926 "in the loaded class C. " \
1927 "Check (3) is available only in debug builds.") \
1928 \
1929 product_pd(intx, InitArrayShortSize, DIAGNOSTIC, \
1930 "Threshold small size (in bytes) for clearing arrays. " \
1931 "Anything this size or smaller may get converted to discrete " \
1932 "scalar stores.") \
1933 range(0, max_intx) \
1934 constraint(InitArrayShortSizeConstraintFunc, AfterErgo) \
1935 \
1936 product(ccstr, AllocateHeapAt, nullptr, \
1937 "Path to the directory where a temporary file will be created " \
1938 "to use as the backing store for Java Heap.") \
1939 \
1940 product_pd(bool, VMContinuations, EXPERIMENTAL, \
1941 "Enable VM continuations support") \
1942 \
1943 develop(bool, LoomDeoptAfterThaw, false, \
1944 "Deopt stack after thaw") \
1945 \
1946 develop(bool, LoomVerifyAfterThaw, false, \
1947 "Verify stack after thaw") \
1948 \
1949 develop(bool, VerifyContinuations, false, \
1950 "Verify continuation consistency") \
1951 \
1952 develop(bool, UseContinuationFastPath, true, \
1953 "Use fast-path frame walking in continuations") \
1954 \
1955 develop(bool, ForceSingleFrameThaw, false, \
1956 "Force thawing one frame at a time") \
1957 \
1958 develop(int, VerifyMetaspaceInterval, DEBUG_ONLY(500) NOT_DEBUG(0), \
1959 "Run periodic metaspace verifications (0 - none, " \
1960 "1 - always, >1 every nth interval)") \
1961 \
1962 product(bool, ShowRegistersOnAssert, true, DIAGNOSTIC, \
1963 "On internal errors, include registers in error report.") \
1964 \
1965 product(bool, UseSwitchProfiling, true, DIAGNOSTIC, \
1966 "leverage profiling for table/lookup switch") \
1967 \
1968 develop(bool, TraceMemoryWriteback, false, \
1969 "Trace memory writeback operations") \
1970 \
1971 JFR_ONLY(product(bool, FlightRecorder, false, \
1972 "(Deprecated) Enable Flight Recorder")) \
1973 \
1974 JFR_ONLY(product(ccstr, FlightRecorderOptions, nullptr, \
1975 "Flight Recorder options")) \
1976 \
1977 JFR_ONLY(product(ccstr, StartFlightRecording, nullptr, \
1978 "Start flight recording with options")) \
1979 \
1980 product(bool, UseFastUnorderedTimeStamps, false, EXPERIMENTAL, \
1981 "Use platform unstable time where supported for timestamps only") \
1982 \
1983 product_pd(bool, InlineTypePassFieldsAsArgs, DIAGNOSTIC, \
1984 "Pass each inline type field as an argument at calls") \
1985 \
1986 product_pd(bool, InlineTypeReturnedAsFields, DIAGNOSTIC, \
1987 "Return fields instead of an inline type reference") \
1988 \
1989 develop(bool, StressCallingConvention, false, \
1990 "Stress the scalarized calling convention.") \
1991 \
1992 develop(bool, PreloadClasses, true, \
1993 "Preloading all classes from the LoadableDescriptors attribute") \
1994 \
1995 product(ccstrlist, ForceNonTearable, "", DIAGNOSTIC, \
1996 "List of inline classes which are forced to be atomic " \
1997 "(whitespace and commas separate names, " \
1998 "and leading and trailing stars '*' are wildcards)") \
1999 \
2000 product(bool, DeoptimizeNMethodBarriersALot, false, DIAGNOSTIC, \
2001 "Make nmethod barriers deoptimise a lot.") \
2002 \
2003 develop(bool, VerifyCrossModifyFence, \
2004 false AARCH64_ONLY(DEBUG_ONLY(||true)), \
2005 "Mark all threads after a safepoint, and clear on a modify " \
2006 "fence. Add cleanliness checks.") \
2007 \
2008 product(bool, UseObjectMonitorTable, true, DIAGNOSTIC, \
2009 "Use a table to record inflated monitors rather than the first " \
2010 "word of the object.") \
2011 \
2012 product(int, FastLockingSpins, 8, DIAGNOSTIC, \
2013 "Specifies the number of times fast locking will attempt to " \
2014 "CAS the markWord before inflating. Between each CAS it will " \
2015 "spin for exponentially more time, resulting in a total number " \
2016 "of spins on the order of O(2^value)") \
2017 range(1, 30) \
2018 \
2019 product(uint, TrimNativeHeapInterval, 0, \
2020 "Interval, in ms, at which the JVM will trim the native heap if " \
2021 "the platform supports that. Lower values will reclaim memory " \
2022 "more eagerly at the cost of higher overhead. A value of 0 " \
2023 "(default) disables native heap trimming.") \
2024 range(0, UINT_MAX) \
2025 \
2026 develop(bool, SimulateFullAddressSpace, false, \
2027 "Simulates a very populated, fragmented address space; no " \
2028 "targeted reservations will succeed.") \
2029 \
2030 product(bool, ProfileExceptionHandlers, true, \
2031 "Profile exception handlers") \
2032 \
2033 product(bool, AlwaysRecordEvolDependencies, true, EXPERIMENTAL, \
2034 "Unconditionally record nmethod dependencies on class " \
2035 "rewriting/transformation independently of the JVMTI " \
2036 "can_{retransform/redefine}_classes capabilities.") \
2037 \
2038 product(bool, UseSecondarySupersCache, true, DIAGNOSTIC, \
2039 "Use secondary supers cache during subtype checks.") \
2040 \
2041 product(bool, UseSecondarySupersTable, false, DIAGNOSTIC, \
2042 "Use hash table to lookup secondary supers.") \
2043 \
2044 product(bool, VerifySecondarySupers, false, DIAGNOSTIC, \
2045 "Check that linear and hashed secondary lookups return the same result.") \
2046 \
2047 product(bool, StressSecondarySupers, false, DIAGNOSTIC, \
2048 "Use a terrible hash function in order to generate many collisions.") \
2049 \
2050 product(bool, UseThreadsLockThrottleLock, true, DIAGNOSTIC, \
2051 "Use an extra lock during Thread start and exit to alleviate" \
2052 "contention on Threads_lock.") \
2053 \
2054 develop(uint, BinarySearchThreshold, 16, \
2055 "Minimal number of elements in a sorted collection to prefer" \
2056 "binary search over simple linear search." ) \
2057 \
2058 product(bool, UseAcmpFastPath, true, DIAGNOSTIC, \
2059 "Use fast path for acmp.") \
2060
2061 // end of RUNTIME_FLAGS
2062
2063 DECLARE_FLAGS(LP64_RUNTIME_FLAGS)
2064 DECLARE_ARCH_FLAGS(ARCH_FLAGS)
2065 DECLARE_FLAGS(RUNTIME_FLAGS)
2066 DECLARE_FLAGS(RUNTIME_OS_FLAGS)
2067
2068 #endif // SHARE_RUNTIME_GLOBALS_HPP