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 *
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 *
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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(bool, UseCompactObjectHeaders, false, EXPERIMENTAL, \
137 "Use compact 64-bit object headers in 64-bit VM") \
138 \
139 product(int, ObjectAlignmentInBytes, 8, \
140 "Default object alignment in bytes, 8 is minimum") \
141 range(8, 256) \
142 constraint(ObjectAlignmentInBytesConstraintFunc, AtParse)
143
144 #else
145 // !_LP64
146
147 #define LP64_RUNTIME_FLAGS(develop, \
148 develop_pd, \
149 product, \
150 product_pd, \
151 range, \
152 constraint)
153 const bool UseCompressedOops = false;
154 const bool UseCompressedClassPointers = false;
155 const bool UseCompactObjectHeaders = false;
156 const int ObjectAlignmentInBytes = 8;
157
158 #endif // _LP64
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(uintx, NUMAChunkResizeWeight, 20, \
213 "Percentage (0-100) used to weight the current sample when " \
214 "computing exponentially decaying average for " \
215 "AdaptiveNUMAChunkSizing") \
216 range(0, 100) \
217 \
218 product(size_t, NUMASpaceResizeRate, 1*G, \
219 "Do not reallocate more than this amount per collection") \
220 range(0, max_uintx) \
221 \
222 product(bool, UseAdaptiveNUMAChunkSizing, true, \
223 "Enable adaptive chunk sizing for NUMA") \
224 \
225 product(bool, NUMAStats, false, \
226 "Print NUMA stats in detailed heap information") \
227 \
228 product(bool, UseAES, false, \
229 "Control whether AES instructions are used when available") \
230 \
231 product(bool, UseFMA, false, \
232 "Control whether FMA instructions are used when available") \
233 \
234 product(bool, UseSHA, false, \
235 "Control whether SHA instructions are used when available") \
236 \
237 product(bool, UseGHASHIntrinsics, false, DIAGNOSTIC, \
238 "Use intrinsics for GHASH versions of crypto") \
239 \
240 product(bool, UseBASE64Intrinsics, false, \
241 "Use intrinsics for java.util.Base64") \
242 \
243 product(bool, UsePoly1305Intrinsics, false, DIAGNOSTIC, \
244 "Use intrinsics for sun.security.util.math.intpoly") \
245 product(bool, UseIntPolyIntrinsics, false, DIAGNOSTIC, \
246 "Use intrinsics for sun.security.util.math.intpoly.MontgomeryIntegerPolynomialP256") \
247 \
248 product(size_t, LargePageSizeInBytes, 0, \
249 "Maximum large page size used (0 will use the default large " \
250 "page size for the environment as the maximum)") \
251 range(0, max_uintx) \
252 \
253 product(size_t, LargePageHeapSizeThreshold, 128*M, \
254 "Use large pages if maximum heap is at least this big") \
255 range(0, max_uintx) \
256 \
257 product(bool, ForceTimeHighResolution, false, \
258 "Using high time resolution (for Win32 only)") \
259 \
260 develop(bool, TracePcPatching, false, \
261 "Trace usage of frame::patch_pc") \
262 \
263 develop(bool, TraceRelocator, false, \
264 "Trace the bytecode relocator") \
265 \
266 \
267 product(bool, SafepointALot, false, DIAGNOSTIC, \
268 "Generate a lot of safepoints. This works with " \
269 "GuaranteedSafepointInterval") \
270 \
271 product(bool, HandshakeALot, false, DIAGNOSTIC, \
272 "Generate a lot of handshakes. This works with " \
273 "GuaranteedSafepointInterval") \
274 \
275 product_pd(bool, BackgroundCompilation, \
276 "A thread requesting compilation is not blocked during " \
277 "compilation") \
278 \
279 product(bool, MethodFlushing, true, \
280 "Reclamation of compiled methods") \
281 \
282 develop(bool, VerifyStack, false, \
283 "Verify stack of each thread when it is entering a runtime call") \
284 \
285 product(bool, ForceUnreachable, false, DIAGNOSTIC, \
286 "Make all non code cache addresses to be unreachable by " \
287 "forcing use of 64bit literal fixups") \
288 \
289 develop(bool, TraceDerivedPointers, false, \
290 "Trace traversal of derived pointers on stack") \
291 \
292 develop(bool, TraceCodeBlobStacks, false, \
293 "Trace stack-walk of codeblobs") \
294 \
295 develop(bool, PrintRewrites, false, \
296 "Print methods that are being rewritten") \
297 \
298 product(bool, UseInlineCaches, true, \
299 "Use Inline Caches for virtual calls ") \
300 \
301 product(bool, InlineArrayCopy, true, DIAGNOSTIC, \
302 "Inline arraycopy native that is known to be part of " \
303 "base library DLL") \
304 \
305 product(bool, InlineObjectHash, true, DIAGNOSTIC, \
306 "Inline Object::hashCode() native that is known to be part " \
307 "of base library DLL") \
308 \
309 product(bool, InlineNatives, true, DIAGNOSTIC, \
310 "Inline natives that are known to be part of base library DLL") \
311 \
312 product(bool, InlineMathNatives, true, DIAGNOSTIC, \
313 "Inline SinD, CosD, etc.") \
314 \
315 product(bool, InlineClassNatives, true, DIAGNOSTIC, \
316 "Inline Class.isInstance, etc") \
317 \
318 product(bool, InlineThreadNatives, true, DIAGNOSTIC, \
319 "Inline Thread.currentThread, etc") \
320 \
321 product(bool, InlineUnsafeOps, true, DIAGNOSTIC, \
322 "Inline memory ops (native methods) from Unsafe") \
323 \
324 product(bool, UseAESIntrinsics, false, DIAGNOSTIC, \
325 "Use intrinsics for AES versions of crypto") \
326 \
327 product(bool, UseAESCTRIntrinsics, false, DIAGNOSTIC, \
328 "Use intrinsics for the paralleled version of AES/CTR crypto") \
329 \
330 product(bool, UseChaCha20Intrinsics, false, DIAGNOSTIC, \
331 "Use intrinsics for the vectorized version of ChaCha20") \
332 \
333 product(bool, UseMD5Intrinsics, false, DIAGNOSTIC, \
334 "Use intrinsics for MD5 crypto hash function") \
335 \
336 product(bool, UseSHA1Intrinsics, false, DIAGNOSTIC, \
337 "Use intrinsics for SHA-1 crypto hash function. " \
338 "Requires that UseSHA is enabled.") \
339 \
340 product(bool, UseSHA256Intrinsics, false, DIAGNOSTIC, \
341 "Use intrinsics for SHA-224 and SHA-256 crypto hash functions. " \
342 "Requires that UseSHA is enabled.") \
343 \
344 product(bool, UseSHA512Intrinsics, false, DIAGNOSTIC, \
345 "Use intrinsics for SHA-384 and SHA-512 crypto hash functions. " \
346 "Requires that UseSHA is enabled.") \
347 \
348 product(bool, UseSHA3Intrinsics, false, DIAGNOSTIC, \
349 "Use intrinsics for SHA3 crypto hash function. " \
350 "Requires that UseSHA is enabled.") \
351 \
352 product(bool, UseCRC32Intrinsics, false, DIAGNOSTIC, \
353 "use intrinsics for java.util.zip.CRC32") \
354 \
355 product(bool, UseCRC32CIntrinsics, false, DIAGNOSTIC, \
356 "use intrinsics for java.util.zip.CRC32C") \
357 \
358 product(bool, UseAdler32Intrinsics, false, DIAGNOSTIC, \
359 "use intrinsics for java.util.zip.Adler32") \
360 \
361 product(bool, UseVectorizedMismatchIntrinsic, false, DIAGNOSTIC, \
362 "Enables intrinsification of ArraysSupport.vectorizedMismatch()") \
363 \
364 product(bool, UseVectorizedHashCodeIntrinsic, false, DIAGNOSTIC, \
365 "Enables intrinsification of ArraysSupport.vectorizedHashCode()") \
366 \
367 product(bool, UseCopySignIntrinsic, false, DIAGNOSTIC, \
368 "Enables intrinsification of Math.copySign") \
369 \
370 product(bool, UseSignumIntrinsic, false, DIAGNOSTIC, \
371 "Enables intrinsification of Math.signum") \
372 \
373 product_pd(bool, DelayCompilerStubsGeneration, DIAGNOSTIC, \
374 "Use Compiler thread for compiler's stubs generation") \
375 \
376 product(ccstrlist, DisableIntrinsic, "", DIAGNOSTIC, \
377 "do not expand intrinsics whose (internal) names appear here") \
378 constraint(DisableIntrinsicConstraintFunc,AfterErgo) \
379 \
380 product(ccstrlist, ControlIntrinsic, "", DIAGNOSTIC, \
381 "Control intrinsics using a list of +/- (internal) names, " \
382 "separated by commas") \
383 constraint(ControlIntrinsicConstraintFunc,AfterErgo) \
384 \
385 develop(ccstr, AddRuntimeUpcallsNOP, nullptr, \
386 "Register a runtime upcall for testing." \
387 "Format is '[upcallType]:[methodFilter]'" \
388 "where upcallType is one of 'onMethodEntry', 'onMethodExit'" \
389 "and methodFilter is one of 'none', 'all'") \
390 \
391 develop(bool, TraceCallFixup, false, \
392 "Trace all call fixups") \
393 \
394 develop(bool, DeoptimizeALot, false, \
395 "Deoptimize at every exit from the runtime system") \
396 \
397 develop(ccstrlist, DeoptimizeOnlyAt, "", \
398 "A comma separated list of bcis to deoptimize at") \
399 \
400 develop(bool, DeoptimizeRandom, false, \
401 "Deoptimize random frames on random exit from the runtime system")\
402 \
403 develop(bool, ZombieALot, false, \
404 "Create non-entrant nmethods at exit from the runtime system") \
405 \
406 develop(bool, WalkStackALot, false, \
407 "Trace stack (no print) at every exit from the runtime system") \
408 \
409 develop(bool, DeoptimizeObjectsALot, false, \
410 "For testing purposes concurrent threads revert optimizations " \
411 "based on escape analysis at intervals given with " \
412 "DeoptimizeObjectsALotInterval=n. The thread count is given " \
413 "with DeoptimizeObjectsALotThreadCountSingle and " \
414 "DeoptimizeObjectsALotThreadCountAll.") \
415 \
416 develop(uint64_t, DeoptimizeObjectsALotInterval, 5, \
417 "Interval for DeoptimizeObjectsALot.") \
418 range(0, max_jlong) \
419 \
420 develop(int, DeoptimizeObjectsALotThreadCountSingle, 1, \
421 "The number of threads that revert optimizations based on " \
422 "escape analysis for a single thread if DeoptimizeObjectsALot " \
423 "is enabled. The target thread is selected round robin." ) \
424 range(0, max_jint) \
425 \
426 develop(int, DeoptimizeObjectsALotThreadCountAll, 1, \
427 "The number of threads that revert optimizations based on " \
428 "escape analysis for all threads if DeoptimizeObjectsALot " \
429 "is enabled." ) \
430 range(0, max_jint) \
431 \
432 develop(bool, VerifyLastFrame, false, \
433 "Verify oops on last frame on entry to VM") \
434 \
435 product(bool, SafepointTimeout, false, \
436 "Time out and warn or fail after SafepointTimeoutDelay " \
437 "milliseconds if failed to reach safepoint") \
438 \
439 product(bool, AbortVMOnSafepointTimeout, false, DIAGNOSTIC, \
440 "Abort upon failure to reach safepoint (see SafepointTimeout)") \
441 \
442 product(uint64_t, AbortVMOnSafepointTimeoutDelay, 0, DIAGNOSTIC, \
443 "Delay in milliseconds for option AbortVMOnSafepointTimeout") \
444 range(0, max_jlong) \
445 \
446 product(bool, AbortVMOnVMOperationTimeout, false, DIAGNOSTIC, \
447 "Abort upon failure to complete VM operation promptly") \
448 \
449 product(intx, AbortVMOnVMOperationTimeoutDelay, 1000, DIAGNOSTIC, \
450 "Delay in milliseconds for option AbortVMOnVMOperationTimeout") \
451 range(0, max_intx) \
452 \
453 product(bool, MaxFDLimit, true, \
454 "Bump the number of file descriptors to maximum (Unix only)") \
455 \
456 product(bool, LogEvents, true, DIAGNOSTIC, \
457 "Enable the various ring buffer event logs") \
458 \
459 product(int, LogEventsBufferEntries, 20, DIAGNOSTIC, \
460 "Number of ring buffer event logs") \
461 range(1, NOT_LP64(1*K) LP64_ONLY(1*M)) \
462 \
463 product(bool, BytecodeVerificationRemote, true, DIAGNOSTIC, \
464 "Enable the Java bytecode verifier for remote classes") \
465 \
466 product(bool, BytecodeVerificationLocal, false, DIAGNOSTIC, \
467 "Enable the Java bytecode verifier for local classes") \
468 \
469 develop(bool, VerifyStackAtCalls, false, \
470 "Verify that the stack pointer is unchanged after calls") \
471 \
472 develop(bool, TraceJavaAssertions, false, \
473 "Trace java language assertions") \
474 \
475 develop(bool, VerifyCodeCache, false, \
476 "Verify code cache on memory allocation/deallocation") \
477 \
478 develop(bool, ZapResourceArea, trueInDebug, \
479 "Zap freed resource/arena space") \
480 \
481 develop(bool, ZapVMHandleArea, trueInDebug, \
482 "Zap freed VM handle space") \
483 \
484 develop(bool, ZapStackSegments, trueInDebug, \
485 "Zap allocated/freed stack segments") \
486 \
487 develop(bool, ZapUnusedHeapArea, trueInDebug, \
488 "Zap unused heap space") \
489 \
490 develop(bool, ZapFillerObjects, trueInDebug, \
491 "Zap filler objects") \
492 \
493 develop(bool, ZapTLAB, trueInDebug, \
494 "Zap allocated TLABs") \
495 \
496 product(bool, ExecutingUnitTests, false, \
497 "Whether the JVM is running unit tests or not") \
498 \
499 develop(uint, ErrorHandlerTest, 0, \
500 "If > 0, provokes an error after VM initialization; the value " \
501 "determines which error to provoke. See controlled_crash() " \
502 "in vmError.cpp.") \
503 range(0, 17) \
504 \
505 develop(uint, TestCrashInErrorHandler, 0, \
506 "If > 0, provokes an error inside VM error handler (a secondary " \
507 "crash). see controlled_crash() in vmError.cpp") \
508 range(0, 17) \
509 \
510 develop(bool, TestSafeFetchInErrorHandler, false , \
511 "If true, tests SafeFetch inside error handler.") \
512 \
513 develop(bool, TestUnresponsiveErrorHandler, false, \
514 "If true, simulates an unresponsive error handler.") \
515 \
516 develop(bool, Verbose, false, \
517 "Print additional debugging information from other modes") \
518 \
519 develop(bool, PrintMiscellaneous, false, \
520 "Print uncategorized debugging information (requires +Verbose)") \
521 \
522 develop(bool, WizardMode, false, \
523 "Print much more debugging information") \
524 \
525 product(bool, ShowMessageBoxOnError, false, \
526 "Keep process alive on VM fatal error") \
527 \
528 product(bool, CreateCoredumpOnCrash, true, \
529 "Create core/mini dump on VM fatal error") \
530 \
531 product(uint64_t, ErrorLogTimeout, 2 * 60, \
532 "Timeout, in seconds, to limit the time spent on writing an " \
533 "error log in case of a crash.") \
534 range(0, (uint64_t)max_jlong/1000) \
535 \
536 product(bool, ErrorLogSecondaryErrorDetails, false, DIAGNOSTIC, \
537 "If enabled, show details on secondary crashes in the error log") \
538 \
539 develop(intx, TraceDwarfLevel, 0, \
540 "Debug levels for the dwarf parser") \
541 range(0, 4) \
542 \
543 product(bool, SuppressFatalErrorMessage, false, \
544 "Report NO fatal error message (avoid deadlock)") \
545 \
546 product(ccstrlist, OnError, "", \
547 "Run user-defined commands on fatal error; see VMError.cpp " \
548 "for examples") \
549 \
550 product(ccstrlist, OnOutOfMemoryError, "", \
551 "Run user-defined commands on first java.lang.OutOfMemoryError " \
552 "thrown from JVM") \
553 \
554 product(bool, HeapDumpBeforeFullGC, false, MANAGEABLE, \
555 "Dump heap to file before any major stop-the-world GC " \
556 "(also see FullGCHeapDumpLimit, HeapDumpPath, HeapDumpGzipLevel)")\
557 \
558 product(bool, HeapDumpAfterFullGC, false, MANAGEABLE, \
559 "Dump heap to file after any major stop-the-world GC " \
560 "(also see FullGCHeapDumpLimit, HeapDumpPath, HeapDumpGzipLevel)")\
561 \
562 product(uint, FullGCHeapDumpLimit, 0, MANAGEABLE, \
563 "Limit the number of heap dumps triggered by " \
564 "HeapDumpBeforeFullGC or HeapDumpAfterFullGC " \
565 "(0 means no limit)") \
566 \
567 product(bool, HeapDumpOnOutOfMemoryError, false, MANAGEABLE, \
568 "Dump heap to file when java.lang.OutOfMemoryError is thrown " \
569 "from JVM " \
570 "(also see HeapDumpPath, HeapDumpGzipLevel)") \
571 \
572 product(ccstr, HeapDumpPath, nullptr, MANAGEABLE, \
573 "When HeapDumpOnOutOfMemoryError, HeapDumpBeforeFullGC " \
574 "or HeapDumpAfterFullGC is on, the path (filename or " \
575 "directory) of the dump file (defaults to java_pid<pid>.hprof " \
576 "in the working directory)") \
577 \
578 product(int, HeapDumpGzipLevel, 0, MANAGEABLE, \
579 "When HeapDumpOnOutOfMemoryError, HeapDumpBeforeFullGC " \
580 "or HeapDumpAfterFullGC is on, the gzip compression " \
581 "level of the dump file. 0 (the default) disables gzip " \
582 "compression. Otherwise the level must be between 1 and 9.") \
583 range(0, 9) \
584 \
585 product(ccstr, NativeMemoryTracking, DEBUG_ONLY("summary") NOT_DEBUG("off"), \
586 "Native memory tracking options") \
587 \
588 product(bool, PrintNMTStatistics, false, DIAGNOSTIC, \
589 "Print native memory tracking summary data if it is on") \
590 \
591 product(bool, LogCompilation, false, DIAGNOSTIC, \
592 "Log compilation activity in detail to LogFile") \
593 \
594 product(bool, PrintCompilation, false, \
595 "Print compilations") \
596 \
597 product(intx, RepeatCompilation, 0, DIAGNOSTIC, \
598 "Repeat compilation without installing code (number of times)") \
599 range(0, max_jint) \
600 \
601 product(bool, PrintExtendedThreadInfo, false, \
602 "Print more information in thread dump") \
603 \
604 product(intx, ScavengeRootsInCode, 2, DIAGNOSTIC, \
605 "0: do not allow scavengable oops in the code cache; " \
606 "1: allow scavenging from the code cache; " \
607 "2: emit as many constants as the compiler can see") \
608 range(0, 2) \
609 \
610 product(bool, AlwaysRestoreFPU, false, \
611 "Restore the FPU control word after every JNI call (expensive)") \
612 \
613 product(bool, PrintCompilation2, false, DIAGNOSTIC, \
614 "Print additional statistics per compilation") \
615 \
616 product(bool, PrintAdapterHandlers, false, DIAGNOSTIC, \
617 "Print code generated for i2c/c2i adapters") \
618 \
619 product(bool, VerifyAdapterCalls, trueInDebug, DIAGNOSTIC, \
620 "Verify that i2c/c2i adapters are called properly") \
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, nullptr, DIAGNOSTIC, \
629 "Print options string passed to disassembler.so") \
630 \
631 develop(bool, PrintNMethodStatistics, false, \
632 "Print a summary statistic for the generated nmethods") \
633 \
634 product(bool, PrintNMethods, false, DIAGNOSTIC, \
635 "Print assembly code for nmethods when generated") \
636 \
637 product(bool, PrintNativeNMethods, false, DIAGNOSTIC, \
638 "Print assembly code for native nmethods when generated") \
639 \
640 develop(bool, PrintDebugInfo, false, \
641 "Print debug information for all nmethods when generated") \
642 \
643 develop(bool, PrintRelocations, false, \
644 "Print relocation information for all nmethods when generated") \
645 \
646 develop(bool, PrintDependencies, false, \
647 "Print dependency information for all nmethods when generated") \
648 \
649 develop(bool, PrintExceptionHandlers, false, \
650 "Print exception handler tables for all nmethods when generated") \
651 \
652 develop(bool, StressCompiledExceptionHandlers, false, \
653 "Exercise compiled exception handlers") \
654 \
655 develop(bool, InterceptOSException, false, \
656 "Start debugger when an implicit OS (e.g. null pointer) " \
657 "exception happens") \
658 \
659 product(bool, PrintCodeCache, false, \
660 "Print the code cache memory usage when exiting") \
661 \
662 develop(bool, PrintCodeCache2, false, \
663 "Print detailed usage information on the code cache when exiting")\
664 \
665 product(bool, PrintCodeCacheOnCompilation, false, \
666 "Print the code cache memory usage each time a method is " \
667 "compiled") \
668 \
669 product(bool, PrintCodeHeapAnalytics, false, DIAGNOSTIC, \
670 "Print code heap usage statistics on exit and on full condition") \
671 \
672 product(bool, PrintStubCode, false, DIAGNOSTIC, \
673 "Print generated stub code") \
674 \
675 product(bool, StackTraceInThrowable, true, \
676 "Collect backtrace in throwable when exception happens") \
677 \
678 product(bool, OmitStackTraceInFastThrow, true, \
679 "Omit backtraces for some 'hot' exceptions in optimized code") \
680 \
681 product(bool, ShowCodeDetailsInExceptionMessages, true, MANAGEABLE, \
682 "Show exception messages from RuntimeExceptions that contain " \
683 "snippets of the failing code. Disable this to improve privacy.") \
684 \
685 product(bool, PrintWarnings, true, \
686 "Print JVM warnings to output stream") \
687 \
688 develop(bool, RegisterReferences, true, \
689 "Tell whether the VM should register soft/weak/final/phantom " \
690 "references") \
691 \
692 develop(bool, PrintCodeCacheExtension, false, \
693 "Print extension of code cache") \
694 \
695 product(bool, ClassUnloading, true, \
696 "Do unloading of classes") \
697 \
698 product(bool, ClassUnloadingWithConcurrentMark, true, \
699 "Do unloading of classes with a concurrent marking cycle") \
700 \
701 develop(bool, PrintSystemDictionaryAtExit, false, \
702 "Print the system dictionary at exit") \
703 \
704 develop(bool, PrintClassLoaderDataGraphAtExit, false, \
705 "Print the class loader data graph at exit") \
706 \
707 product(bool, AllowParallelDefineClass, false, \
708 "Allow parallel defineClass requests for class loaders " \
709 "registering as parallel capable") \
710 \
711 product(bool, DisablePrimordialThreadGuardPages, false, EXPERIMENTAL, \
712 "Disable the use of stack guard pages if the JVM is loaded " \
713 "on the primordial process thread") \
714 \
715 product(bool, DoJVMTIVirtualThreadTransitions, true, EXPERIMENTAL, \
716 "Do JVMTI virtual thread mount/unmount transitions " \
717 "(disabling this flag implies no JVMTI events are posted)") \
718 \
719 /* notice: the max range value here is max_jint, not max_intx */ \
720 /* because of overflow issue */ \
721 product(intx, AsyncDeflationInterval, 250, DIAGNOSTIC, \
722 "Async deflate idle monitors every so many milliseconds when " \
723 "MonitorUsedDeflationThreshold is exceeded (0 is off).") \
724 range(0, max_jint) \
725 \
726 /* notice: the max range value here is max_jint, not max_intx */ \
727 /* because of overflow issue */ \
728 product(intx, GuaranteedAsyncDeflationInterval, 60000, DIAGNOSTIC, \
729 "Async deflate idle monitors every so many milliseconds even " \
730 "when MonitorUsedDeflationThreshold is NOT exceeded (0 is off).") \
731 range(0, max_jint) \
732 \
733 product(size_t, AvgMonitorsPerThreadEstimate, 1024, DIAGNOSTIC, \
734 "Used to estimate a variable ceiling based on number of threads " \
735 "for use with MonitorUsedDeflationThreshold (0 is off).") \
736 range(0, max_uintx) \
737 \
738 /* notice: the max range value here is max_jint, not max_intx */ \
739 /* because of overflow issue */ \
740 product(intx, MonitorDeflationMax, 1000000, DIAGNOSTIC, \
741 "The maximum number of monitors to deflate, unlink and delete " \
742 "at one time (minimum is 1024).") \
743 range(1024, max_jint) \
744 \
745 product(intx, MonitorUnlinkBatch, 500, DIAGNOSTIC, \
746 "The maximum number of monitors to unlink in one batch. ") \
747 range(1, max_jint) \
748 \
749 product(int, MonitorUsedDeflationThreshold, 90, DIAGNOSTIC, \
750 "Percentage of used monitors before triggering deflation (0 is " \
751 "off). The check is performed on AsyncDeflationInterval or " \
752 "GuaranteedAsyncDeflationInterval, whichever is lower.") \
753 range(0, 100) \
754 \
755 product(uintx, NoAsyncDeflationProgressMax, 3, DIAGNOSTIC, \
756 "Max number of no progress async deflation attempts to tolerate " \
757 "before adjusting the in_use_list_ceiling up (0 is off).") \
758 range(0, max_uintx) \
759 \
760 product(intx, hashCode, 5, EXPERIMENTAL, \
761 "(Unstable) select hashCode generation algorithm") \
762 \
763 product(bool, ReduceSignalUsage, false, \
764 "Reduce the use of OS signals in Java and/or the VM") \
765 \
766 develop(bool, LoadLineNumberTables, true, \
767 "Tell whether the class file parser loads line number tables") \
768 \
769 develop(bool, LoadLocalVariableTables, true, \
770 "Tell whether the class file parser loads local variable tables") \
771 \
772 develop(bool, LoadLocalVariableTypeTables, true, \
773 "Tell whether the class file parser loads local variable type" \
774 "tables") \
775 \
776 product(bool, AllowUserSignalHandlers, false, \
777 "Application will install primary signal handlers for the JVM " \
778 "(Unix only)") \
779 \
780 product(bool, UseSignalChaining, true, \
781 "Use signal-chaining to invoke signal handlers installed " \
782 "by the application (Unix only)") \
783 \
784 product(bool, RestoreMXCSROnJNICalls, false, \
785 "Restore MXCSR when returning from JNI calls") \
786 \
787 product(bool, CheckJNICalls, false, \
788 "Verify all arguments to JNI calls") \
789 \
790 product(bool, UseFastJNIAccessors, true, \
791 "Use optimized versions of Get<Primitive>Field") \
792 \
793 product(intx, MaxJNILocalCapacity, 65536, \
794 "Maximum allowable local JNI handle capacity to " \
795 "EnsureLocalCapacity() and PushLocalFrame(), " \
796 "where <= 0 is unlimited, default: 65536") \
797 range(min_intx, max_intx) \
798 \
799 product(bool, EagerXrunInit, false, \
800 "Eagerly initialize -Xrun libraries; allows startup profiling, " \
801 "but not all -Xrun libraries may support the state of the VM " \
802 "at this time") \
803 \
804 develop(uintx, PreallocatedOutOfMemoryErrorCount, 4, \
805 "Number of OutOfMemoryErrors preallocated with backtrace") \
806 \
807 product(bool, UseXMMForArrayCopy, false, \
808 "Use SSE2 MOVQ instruction for Arraycopy") \
809 \
810 develop(bool, PrintFieldLayout, false, \
811 "Print field layout for each class") \
812 \
813 /* Need to limit the extent of the padding to reasonable size. */\
814 /* 8K is well beyond the reasonable HW cache line size, even with */\
815 /* aggressive prefetching, while still leaving the room for segregating */\
816 /* among the distinct pages. */\
817 product(int, ContendedPaddingWidth, 128, \
818 "How many bytes to pad the fields/classes marked @Contended with")\
819 range(0, 8192) \
820 constraint(ContendedPaddingWidthConstraintFunc,AfterErgo) \
821 \
822 product(bool, EnableContended, true, \
823 "Enable @Contended annotation support") \
824 \
825 product(bool, RestrictContended, true, \
826 "Restrict @Contended to trusted classes") \
827 \
828 product(int, DiagnoseSyncOnValueBasedClasses, 0, DIAGNOSTIC, \
829 "Detect and take action upon identifying synchronization on " \
830 "value based classes. Modes: " \
831 "0: off; " \
832 "1: exit with fatal error; " \
833 "2: log message to stdout. Output file can be specified with " \
834 " -Xlog:valuebasedclasses. If JFR is running it will " \
835 " also generate JFR events.") \
836 range(0, 2) \
837 \
838 product(bool, ExitOnOutOfMemoryError, false, \
839 "JVM exits on the first occurrence of an out-of-memory error " \
840 "thrown from JVM") \
841 \
842 product(bool, CrashOnOutOfMemoryError, false, \
843 "JVM aborts, producing an error log and core/mini dump, on the " \
844 "first occurrence of an out-of-memory error thrown from JVM") \
845 \
846 product(intx, UserThreadWaitAttemptsAtExit, 30, \
847 "The number of times to wait for user threads to stop executing " \
848 "native code during JVM exit. Each wait lasts 10 milliseconds. " \
849 "The maximum number of waits is 1000, to wait at most 10 " \
850 "seconds.") \
851 range(0, 1000) \
852 \
853 /* tracing */ \
854 \
855 develop(bool, StressRewriter, false, \
856 "Stress linktime bytecode rewriting") \
857 \
858 product(ccstr, TraceJVMTI, nullptr, \
859 "Trace flags for JVMTI functions and events") \
860 \
861 product(bool, StressLdcRewrite, false, DIAGNOSTIC, \
862 "Force ldc -> ldc_w rewrite during RedefineClasses. " \
863 "This option can change an EMCP method into an obsolete method " \
864 "and can affect tests that expect specific methods to be EMCP. " \
865 "This option should be used with caution.") \
866 \
867 product(bool, AllowRedefinitionToAddDeleteMethods, false, \
868 "(Deprecated) Allow redefinition to add and delete private " \
869 "static or final methods for compatibility with old releases") \
870 \
871 develop(bool, TraceBytecodes, false, \
872 "Trace bytecode execution") \
873 \
874 develop(bool, TraceBytecodesTruncated, false, \
875 "Truncate non control-flow bytecode when tracing bytecode") \
876 \
877 develop(bool, VerifyDependencies, trueInDebug, \
878 "Exercise and verify the compilation dependency mechanism") \
879 \
880 develop(bool, TraceNewOopMapGeneration, false, \
881 "Trace OopMapGeneration") \
882 \
883 develop(bool, TraceNewOopMapGenerationDetailed, false, \
884 "Trace OopMapGeneration: print detailed cell states") \
885 \
886 develop(bool, TimeOopMap, false, \
887 "Time calls to GenerateOopMap::compute_map() in sum") \
888 \
889 develop(bool, TimeOopMap2, false, \
890 "Time calls to GenerateOopMap::compute_map() individually") \
891 \
892 develop(bool, TraceOopMapRewrites, false, \
893 "Trace rewriting of methods during oop map generation") \
894 \
895 develop(bool, TraceFinalizerRegistration, false, \
896 "Trace registration of final references") \
897 \
898 product(bool, IgnoreEmptyClassPaths, false, \
899 "Ignore empty path elements in -classpath") \
900 \
901 product(bool, PrintHeapAtSIGBREAK, true, \
902 "Print heap layout in response to SIGBREAK") \
903 \
904 product(bool, PrintClassHistogram, false, MANAGEABLE, \
905 "Print a histogram of class instances") \
906 \
907 product(double, ObjectCountCutOffPercent, 0.5, EXPERIMENTAL, \
908 "The percentage of the used heap that the instances of a class " \
909 "must occupy for the class to generate a trace event") \
910 range(0.0, 100.0) \
911 \
912 /* JVMTI heap profiling */ \
913 \
914 product(bool, VerifyBeforeIteration, false, DIAGNOSTIC, \
915 "Verify memory system before JVMTI iteration") \
916 \
917 /* compiler */ \
918 \
919 /* notice: the max range value here is max_jint, not max_intx */ \
920 /* because of overflow issue */ \
921 product(intx, CICompilerCount, CI_COMPILER_COUNT, \
922 "Number of compiler threads to run") \
923 range(0, max_jint) \
924 constraint(CICompilerCountConstraintFunc, AfterErgo) \
925 \
926 product(bool, UseDynamicNumberOfCompilerThreads, true, \
927 "Dynamically choose the number of parallel compiler threads") \
928 \
929 product(bool, ReduceNumberOfCompilerThreads, true, DIAGNOSTIC, \
930 "Reduce the number of parallel compiler threads when they " \
931 "are not used") \
932 \
933 product(bool, TraceCompilerThreads, false, DIAGNOSTIC, \
934 "Trace creation and removal of compiler threads") \
935 \
936 product(ccstr, LogClassLoadingCauseFor, nullptr, \
937 "Apply -Xlog:class+load+cause* to classes whose fully " \
938 "qualified name contains this string (\"*\" matches " \
939 "any class).") \
940 \
941 develop(bool, InjectCompilerCreationFailure, false, \
942 "Inject thread creation failures for " \
943 "UseDynamicNumberOfCompilerThreads") \
944 \
945 develop(bool, GenerateSynchronizationCode, true, \
946 "generate locking/unlocking code for synchronized methods and " \
947 "monitors") \
948 \
949 product_pd(bool, ImplicitNullChecks, DIAGNOSTIC, \
950 "Generate code for implicit null checks") \
951 \
952 product_pd(bool, TrapBasedNullChecks, \
953 "Generate code for null checks that uses a cmp and trap " \
954 "instruction raising SIGTRAP. This is only used if an access to" \
955 "null (+offset) will not raise a SIGSEGV, i.e.," \
956 "ImplicitNullChecks don't work (PPC64).") \
957 \
958 product(bool, EnableThreadSMRStatistics, trueInDebug, DIAGNOSTIC, \
959 "Enable Thread SMR Statistics") \
960 \
961 product(bool, Inline, true, \
962 "Enable inlining") \
963 \
964 product(bool, ClipInlining, true, \
965 "Clip inlining if aggregate method exceeds DesiredMethodLimit") \
966 \
967 develop(bool, UseCHA, true, \
968 "Enable CHA") \
969 \
970 product(bool, UseTypeProfile, true, \
971 "Check interpreter profile for historically monomorphic calls") \
972 \
973 product(bool, PrintInlining, false, DIAGNOSTIC, \
974 "Print inlining optimizations") \
975 \
976 product(bool, UsePopCountInstruction, false, \
977 "Use population count instruction") \
978 \
979 develop(bool, TraceMethodReplacement, false, \
980 "Print when methods are replaced do to recompilation") \
981 \
982 product(intx, MinPassesBeforeFlush, 10, DIAGNOSTIC, \
983 "Minimum number of sweeper passes before an nmethod " \
984 "can be flushed") \
985 range(0, max_intx) \
986 \
987 develop(bool, StressCodeBuffers, false, \
988 "Exercise code buffer expansion and other rare state changes") \
989 \
990 product(bool, DebugNonSafepoints, trueInDebug, DIAGNOSTIC, \
991 "Generate extra debugging information for non-safepoints in " \
992 "nmethods") \
993 \
994 product(bool, PrintVMOptions, false, \
995 "Print flags that appeared on the command line") \
996 \
997 product(bool, IgnoreUnrecognizedVMOptions, false, \
998 "Ignore unrecognized VM options") \
999 \
1000 product(bool, PrintCommandLineFlags, false, \
1001 "Print flags specified on command line or set by ergonomics") \
1002 \
1003 product(bool, PrintFlagsInitial, false, \
1004 "Print all VM flags before argument processing and exit VM") \
1005 \
1006 product(bool, PrintFlagsFinal, false, \
1007 "Print all VM flags after argument and ergonomic processing") \
1008 \
1009 develop(bool, PrintFlagsWithComments, false, \
1010 "Print all VM flags with default values and descriptions and " \
1011 "exit") \
1012 \
1013 product(bool, PrintFlagsRanges, false, \
1014 "Print VM flags and their ranges") \
1015 \
1016 product(bool, SerializeVMOutput, true, DIAGNOSTIC, \
1017 "Use a mutex to serialize output to tty and LogFile") \
1018 \
1019 product(bool, DisplayVMOutput, true, DIAGNOSTIC, \
1020 "Display all VM output on the tty, independently of LogVMOutput") \
1021 \
1022 product(bool, LogVMOutput, false, DIAGNOSTIC, \
1023 "Save VM output to LogFile") \
1024 \
1025 product(ccstr, LogFile, nullptr, DIAGNOSTIC, \
1026 "If LogVMOutput or LogCompilation is on, save VM output to " \
1027 "this file [default: ./hotspot_%p.log] (%p replaced with pidNNN)")\
1028 \
1029 product(ccstr, ErrorFile, nullptr, \
1030 "If an error occurs, save the error data to this file " \
1031 "[default: ./hs_err_%p.log] (%p replaced with pidNNN)") \
1032 \
1033 product(bool, ExtensiveErrorReports, \
1034 PRODUCT_ONLY(false) NOT_PRODUCT(true), \
1035 "Error reports are more extensive.") \
1036 \
1037 product(bool, DisplayVMOutputToStderr, false, \
1038 "If DisplayVMOutput is true, display all VM output to stderr") \
1039 \
1040 product(bool, DisplayVMOutputToStdout, false, \
1041 "If DisplayVMOutput is true, display all VM output to stdout") \
1042 \
1043 product(bool, ErrorFileToStderr, false, \
1044 "If true, error data is printed to stderr instead of a file") \
1045 \
1046 product(bool, ErrorFileToStdout, false, \
1047 "If true, error data is printed to stdout instead of a file") \
1048 \
1049 develop(bool, VerifyHeavyMonitors, false, \
1050 "Checks that no stack locking happens when using " \
1051 "-XX:LockingMode=0 (LM_MONITOR)") \
1052 \
1053 product(bool, PrintStringTableStatistics, false, \
1054 "print statistics about the StringTable and SymbolTable") \
1055 \
1056 product(bool, VerifyStringTableAtExit, false, DIAGNOSTIC, \
1057 "verify StringTable contents at exit") \
1058 \
1059 develop(bool, PrintSymbolTableSizeHistogram, false, \
1060 "print histogram of the symbol table") \
1061 \
1062 product(ccstr, AbortVMOnException, nullptr, DIAGNOSTIC, \
1063 "Call fatal if this exception is thrown. Example: " \
1064 "java -XX:AbortVMOnException=java.lang.NullPointerException Foo") \
1065 \
1066 product(ccstr, AbortVMOnExceptionMessage, nullptr, DIAGNOSTIC, \
1067 "Call fatal if the exception pointed by AbortVMOnException " \
1068 "has this message") \
1069 \
1070 develop(bool, DebugVtables, false, \
1071 "add debugging code to vtable dispatch") \
1072 \
1073 product(bool, RangeCheckElimination, true, \
1074 "Eliminate range checks") \
1075 \
1076 develop_pd(bool, UncommonNullCast, \
1077 "track occurrences of null in casts; adjust compiler tactics") \
1078 \
1079 develop(bool, TypeProfileCasts, true, \
1080 "treat casts like calls for purposes of type profiling") \
1081 \
1082 develop(bool, TraceLivenessGen, false, \
1083 "Trace the generation of liveness analysis information") \
1084 \
1085 develop(bool, TraceLivenessQuery, false, \
1086 "Trace queries of liveness analysis information") \
1087 \
1088 develop(bool, CollectIndexSetStatistics, false, \
1089 "Collect information about IndexSets") \
1090 \
1091 develop(int, FastAllocateSizeLimit, 128*K, \
1092 /* Note: This value is zero mod 1<<13 for a cheap sparc set. */ \
1093 "Inline allocations larger than this in doublewords must go slow")\
1094 \
1095 product_pd(bool, CompactStrings, \
1096 "Enable Strings to use single byte chars in backing store") \
1097 \
1098 product_pd(uint, TypeProfileLevel, \
1099 "=XYZ, with Z: Type profiling of arguments at call; " \
1100 "Y: Type profiling of return value at call; " \
1101 "X: Type profiling of parameters to methods; " \
1102 "X, Y and Z in 0=off ; 1=jsr292 only; 2=all methods") \
1103 constraint(TypeProfileLevelConstraintFunc, AfterErgo) \
1104 \
1105 product(int, TypeProfileArgsLimit, 2, \
1106 "max number of call arguments to consider for type profiling") \
1107 range(0, 16) \
1108 \
1109 product(int, TypeProfileParmsLimit, 2, \
1110 "max number of incoming parameters to consider for type profiling"\
1111 ", -1 for all") \
1112 range(-1, 64) \
1113 \
1114 /* statistics */ \
1115 develop(bool, CountCompiledCalls, false, \
1116 "Count method invocations") \
1117 \
1118 develop(bool, ICMissHistogram, false, \
1119 "Produce histogram of IC misses") \
1120 \
1121 /* interpreter */ \
1122 product_pd(bool, RewriteBytecodes, \
1123 "Allow rewriting of bytecodes (bytecodes are not immutable)") \
1124 \
1125 product_pd(bool, RewriteFrequentPairs, \
1126 "Rewrite frequently used bytecode pairs into a single bytecode") \
1127 \
1128 product(bool, PrintInterpreter, false, DIAGNOSTIC, \
1129 "Print the generated interpreter code") \
1130 \
1131 product(bool, UseInterpreter, true, \
1132 "Use interpreter for non-compiled methods") \
1133 \
1134 develop(bool, UseFastSignatureHandlers, true, \
1135 "Use fast signature handlers for native calls") \
1136 \
1137 product(bool, UseLoopCounter, true, \
1138 "Increment invocation counter on backward branch") \
1139 \
1140 product_pd(bool, UseOnStackReplacement, \
1141 "Use on stack replacement, calls runtime if invoc. counter " \
1142 "overflows in loop") \
1143 \
1144 develop(bool, TraceOnStackReplacement, false, \
1145 "Trace on stack replacement") \
1146 \
1147 product_pd(bool, PreferInterpreterNativeStubs, \
1148 "Use always interpreter stubs for native methods invoked via " \
1149 "interpreter") \
1150 \
1151 product(bool, CountBytecodes, false, DIAGNOSTIC, \
1152 "Count number of bytecodes executed") \
1153 \
1154 product(bool, CountBytecodesPerThread, false, DIAGNOSTIC, \
1155 "Count number of bytecodes executed per thread") \
1156 \
1157 product(bool, PrintBytecodeHistogram, false, DIAGNOSTIC, \
1158 "Print histogram of the executed bytecodes") \
1159 \
1160 product(double, PrintBytecodeHistogramCutoff, 0.01, \
1161 "Print cutoff for histogram of the executed bytecodes") \
1162 range(0.0, 100.0) \
1163 \
1164 develop(bool, PrintBytecodePairHistogram, false, \
1165 "Print histogram of the executed bytecode pairs") \
1166 \
1167 product(bool, PrintSignatureHandlers, false, DIAGNOSTIC, \
1168 "Print code generated for native method signature handlers") \
1169 \
1170 develop(bool, VerifyOops, false, \
1171 "Do plausibility checks for oops") \
1172 \
1173 develop(bool, CheckUnhandledOops, false, \
1174 "Check for unhandled oops in VM code") \
1175 \
1176 develop(bool, VerifyJNIFields, trueInDebug, \
1177 "Verify jfieldIDs for instance fields") \
1178 \
1179 develop(bool, VerifyFPU, false, \
1180 "Verify FPU state (check for NaN's, etc.)") \
1181 \
1182 develop(bool, VerifyActivationFrameSize, false, \
1183 "Verify that activation frame didn't become smaller than its " \
1184 "minimal size") \
1185 \
1186 develop(bool, TraceFrequencyInlining, false, \
1187 "Trace frequency based inlining") \
1188 \
1189 develop_pd(bool, InlineIntrinsics, \
1190 "Use intrinsics in Interpreter that can be statically resolved") \
1191 \
1192 product_pd(bool, ProfileInterpreter, \
1193 "Profile at the bytecode level during interpretation") \
1194 \
1195 develop_pd(bool, ProfileTraps, \
1196 "Profile deoptimization traps at the bytecode level") \
1197 \
1198 product(intx, ProfileMaturityPercentage, 20, \
1199 "number of method invocations/branches (expressed as % of " \
1200 "CompileThreshold) before using the method's profile") \
1201 range(0, 100) \
1202 \
1203 product(bool, ForceProfiling, false, DIAGNOSTIC, \
1204 "Eagerly allocate MDOs") \
1205 \
1206 product(bool, PrintMethodData, false, DIAGNOSTIC, \
1207 "Print the results of +ProfileInterpreter at end of run") \
1208 \
1209 develop(bool, VerifyDataPointer, trueInDebug, \
1210 "Verify the method data pointer during interpreter profiling") \
1211 \
1212 develop(bool, CrashGCForDumpingJavaThread, false, \
1213 "Manually make GC thread crash then dump java stack trace; " \
1214 "Test only") \
1215 \
1216 /* compilation */ \
1217 product(bool, UseCompiler, true, \
1218 "Use Just-In-Time compilation") \
1219 \
1220 product(bool, AlwaysCompileLoopMethods, false, \
1221 "When using recompilation, never interpret methods " \
1222 "containing loops") \
1223 \
1224 product(int, AllocatePrefetchStyle, 1, \
1225 "0 = no prefetch, " \
1226 "1 = generate prefetch instructions for each allocation, " \
1227 "2 = use TLAB watermark to gate allocation prefetch, " \
1228 "3 = generate one prefetch instruction per cache line") \
1229 range(0, 3) \
1230 \
1231 product(int, AllocatePrefetchDistance, -1, \
1232 "Distance to prefetch ahead of allocation pointer. " \
1233 "-1: use system-specific value (automatically determined") \
1234 range(-1, 512) \
1235 \
1236 product(int, AllocatePrefetchLines, 3, \
1237 "Number of lines to prefetch ahead of array allocation pointer") \
1238 range(1, 64) \
1239 \
1240 product(int, AllocateInstancePrefetchLines, 1, \
1241 "Number of lines to prefetch ahead of instance allocation " \
1242 "pointer") \
1243 range(1, 64) \
1244 \
1245 product(int, AllocatePrefetchStepSize, 16, \
1246 "Step size in bytes of sequential prefetch instructions") \
1247 range(1, 512) \
1248 constraint(AllocatePrefetchStepSizeConstraintFunc,AfterMemoryInit)\
1249 \
1250 product(intx, AllocatePrefetchInstr, 0, \
1251 "Select instruction to prefetch ahead of allocation pointer") \
1252 constraint(AllocatePrefetchInstrConstraintFunc, AfterMemoryInit) \
1253 \
1254 /* deoptimization */ \
1255 product(bool, TraceDeoptimization, false, DIAGNOSTIC, \
1256 "Trace deoptimization") \
1257 \
1258 develop(bool, PrintDeoptimizationDetails, false, \
1259 "Print more information about deoptimization") \
1260 \
1261 develop(bool, DebugDeoptimization, false, \
1262 "Tracing various information while debugging deoptimization") \
1263 \
1264 product(double, SelfDestructTimer, 0.0, \
1265 "Will cause VM to terminate after a given time " \
1266 "(in fractional minutes) " \
1267 "(0.0 means off)") \
1268 range(0.0, (double)max_intx) \
1269 \
1270 product(int, MaxJavaStackTraceDepth, 1024, \
1271 "The maximum number of lines in the stack trace for Java " \
1272 "exceptions (0 means all)") \
1273 range(0, max_jint/2) \
1274 \
1275 /* notice: the max range value here is max_jint, not max_intx */ \
1276 /* because of overflow issue */ \
1277 product(intx, GuaranteedSafepointInterval, 0, DIAGNOSTIC, \
1278 "Guarantee a safepoint (at least) every so many milliseconds " \
1279 "(0 means none)") \
1280 range(0, max_jint) \
1281 \
1282 product(intx, ServiceThreadCleanupInterval, 1000, DIAGNOSTIC, \
1283 "Wake the ServiceThread to do periodic cleanup checks every so " \
1284 "many milliseconds (0 means none)") \
1285 range(0, max_jint) \
1286 \
1287 product(double, SafepointTimeoutDelay, 10000, \
1288 "Delay in milliseconds for option SafepointTimeout; " \
1289 "supports sub-millisecond resolution with fractional values.") \
1290 range(0, max_jlongDouble LP64_ONLY(/MICROUNITS)) \
1291 \
1292 product(bool, UseSystemMemoryBarrier, false, \
1293 "Try to enable system memory barrier if supported by OS") \
1294 \
1295 product(intx, NmethodSweepActivity, 4, \
1296 "Removes cold nmethods from code cache if > 0. Higher values " \
1297 "result in more aggressive sweeping") \
1298 range(0, 2000) \
1299 \
1300 develop(intx, MallocCatchPtr, -1, \
1301 "Hit breakpoint when mallocing/freeing this pointer") \
1302 \
1303 develop(int, StackPrintLimit, 100, \
1304 "number of stack frames to print in VM-level stack dump") \
1305 \
1306 product(int, ErrorLogPrintCodeLimit, 3, DIAGNOSTIC, \
1307 "max number of compiled code units to print in error log") \
1308 range(0, VMError::max_error_log_print_code) \
1309 \
1310 develop(int, MaxElementPrintSize, 256, \
1311 "maximum number of elements to print") \
1312 \
1313 develop(int, MaxStringPrintSize, 256, \
1314 "maximum number of characters to print for a java.lang.String " \
1315 "in the VM. If exceeded, an abridged version of the string is " \
1316 "printed with the middle of the string elided.") \
1317 range(2, O_BUFLEN) \
1318 \
1319 develop(intx, MaxSubklassPrintSize, 4, \
1320 "maximum number of subklasses to print when printing klass") \
1321 \
1322 develop(intx, MaxForceInlineLevel, 100, \
1323 "maximum number of nested calls that are forced for inlining " \
1324 "(using CompileCommand or marked w/ @ForceInline)") \
1325 range(0, max_jint) \
1326 \
1327 develop(intx, MethodHistogramCutoff, 100, \
1328 "The cutoff value for method invocation histogram (+CountCalls)") \
1329 \
1330 develop(intx, DeoptimizeALotInterval, 5, \
1331 "Number of exits until DeoptimizeALot kicks in") \
1332 \
1333 develop(intx, ZombieALotInterval, 5, \
1334 "Number of exits until ZombieALot kicks in") \
1335 \
1336 product(ccstr, MallocLimit, nullptr, DIAGNOSTIC, \
1337 "Limit malloc allocation size from VM. Reaching a limit will " \
1338 "trigger an action (see flag). This feature requires " \
1339 "NativeMemoryTracking=summary or NativeMemoryTracking=detail." \
1340 "Usage:" \
1341 "\"-XX:MallocLimit=<size>[:<flag>]\" sets a total limit." \
1342 "\"-XX:MallocLimit=<category>:<size>[:<flag>][,<category>:<size>[:<flag>] ...]\"" \
1343 "sets one or more category-specific limits." \
1344 "<flag> defines the action upon reaching the limit:" \
1345 "\"fatal\": end VM with a fatal error at the allocation site" \
1346 "\"oom\" : will mimic a native OOM" \
1347 "If <flag> is omitted, \"fatal\" is the default." \
1348 "Examples:\n" \
1349 "-XX:MallocLimit=2g" \
1350 "-XX:MallocLimit=2g:oom" \
1351 "-XX:MallocLimit=compiler:200m:oom,code:100m") \
1352 \
1353 product(intx, TypeProfileWidth, 2, \
1354 "Number of receiver types to record in call/cast profile") \
1355 range(0, 8) \
1356 \
1357 develop(intx, BciProfileWidth, 2, \
1358 "Number of return bci's to record in ret profile") \
1359 \
1360 product(intx, PerMethodRecompilationCutoff, 400, \
1361 "After recompiling N times, stay in the interpreter (-1=>'Inf')") \
1362 range(-1, max_intx) \
1363 \
1364 product(intx, PerBytecodeRecompilationCutoff, 200, \
1365 "Per-BCI limit on repeated recompilation (-1=>'Inf')") \
1366 range(-1, max_intx) \
1367 \
1368 product(intx, PerMethodTrapLimit, 100, \
1369 "Limit on traps (of one kind) in a method (includes inlines)") \
1370 range(0, max_jint) \
1371 \
1372 product(intx, PerMethodSpecTrapLimit, 5000, EXPERIMENTAL, \
1373 "Limit on speculative traps (of one kind) in a method " \
1374 "(includes inlines)") \
1375 range(0, max_jint) \
1376 \
1377 product(intx, PerBytecodeTrapLimit, 4, \
1378 "Limit on traps (of one kind) at a particular BCI") \
1379 range(0, max_jint) \
1380 \
1381 product(int, SpecTrapLimitExtraEntries, 3, EXPERIMENTAL, \
1382 "Extra method data trap entries for speculation") \
1383 \
1384 product(double, InlineFrequencyRatio, 0.25, DIAGNOSTIC, \
1385 "Ratio of call site execution to caller method invocation") \
1386 \
1387 product(double, MinInlineFrequencyRatio, 0.0085, DIAGNOSTIC, \
1388 "Minimum ratio of call site execution to caller method" \
1389 "invocation to be considered for inlining") \
1390 \
1391 develop(intx, InlineThrowCount, 50, \
1392 "Force inlining of interpreted methods that throw this often") \
1393 range(0, max_jint) \
1394 \
1395 develop(intx, InlineThrowMaxSize, 200, \
1396 "Force inlining of throwing methods smaller than this") \
1397 range(0, max_jint) \
1398 \
1399 product(size_t, MetaspaceSize, NOT_LP64(16 * M) LP64_ONLY(21 * M), \
1400 "Initial threshold (in bytes) at which a garbage collection " \
1401 "is done to reduce Metaspace usage") \
1402 constraint(MetaspaceSizeConstraintFunc,AfterErgo) \
1403 \
1404 product(size_t, MaxMetaspaceSize, max_uintx, \
1405 "Maximum size of Metaspaces (in bytes)") \
1406 constraint(MaxMetaspaceSizeConstraintFunc,AfterErgo) \
1407 \
1408 product(size_t, CompressedClassSpaceSize, 1*G, \
1409 "Maximum size of class area in Metaspace when compressed " \
1410 "class pointers are used") \
1411 range(1*M, LP64_ONLY(4*G) NOT_LP64(max_uintx)) \
1412 \
1413 develop(size_t, CompressedClassSpaceBaseAddress, 0, \
1414 "Force the class space to be allocated at this address or " \
1415 "fails VM initialization (requires -Xshare=off.") \
1416 \
1417 develop(bool, RandomizeClassSpaceLocation, true, \
1418 "Randomize location of class space.") \
1419 \
1420 product(bool, PrintMetaspaceStatisticsAtExit, false, DIAGNOSTIC, \
1421 "Print metaspace statistics upon VM exit.") \
1422 \
1423 product(uintx, MinHeapFreeRatio, 40, MANAGEABLE, \
1424 "The minimum percentage of heap free after GC to avoid expansion."\
1425 " For most GCs this applies to the old generation. In G1 and" \
1426 " ParallelGC it applies to the whole heap.") \
1427 range(0, 100) \
1428 constraint(MinHeapFreeRatioConstraintFunc,AfterErgo) \
1429 \
1430 product(uintx, MaxHeapFreeRatio, 70, MANAGEABLE, \
1431 "The maximum percentage of heap free after GC to avoid shrinking."\
1432 " For most GCs this applies to the old generation. In G1 and" \
1433 " ParallelGC it applies to the whole heap.") \
1434 range(0, 100) \
1435 constraint(MaxHeapFreeRatioConstraintFunc,AfterErgo) \
1436 \
1437 product(intx, SoftRefLRUPolicyMSPerMB, 1000, \
1438 "Number of milliseconds per MB of free space in the heap") \
1439 range(0, max_intx) \
1440 constraint(SoftRefLRUPolicyMSPerMBConstraintFunc,AfterMemoryInit) \
1441 \
1442 product(size_t, MinHeapDeltaBytes, ScaleForWordSize(128*K), \
1443 "The minimum change in heap space due to GC (in bytes)") \
1444 range(0, max_uintx) \
1445 \
1446 product(size_t, MinMetaspaceExpansion, ScaleForWordSize(256*K), \
1447 "The minimum expansion of Metaspace (in bytes)") \
1448 range(0, max_uintx) \
1449 \
1450 product(uint, MaxMetaspaceFreeRatio, 70, \
1451 "The maximum percentage of Metaspace free after GC to avoid " \
1452 "shrinking") \
1453 range(0, 100) \
1454 constraint(MaxMetaspaceFreeRatioConstraintFunc,AfterErgo) \
1455 \
1456 product(uint, MinMetaspaceFreeRatio, 40, \
1457 "The minimum percentage of Metaspace free after GC to avoid " \
1458 "expansion") \
1459 range(0, 99) \
1460 constraint(MinMetaspaceFreeRatioConstraintFunc,AfterErgo) \
1461 \
1462 product(size_t, MaxMetaspaceExpansion, ScaleForWordSize(4*M), \
1463 "The maximum expansion of Metaspace without full GC (in bytes)") \
1464 range(0, max_uintx) \
1465 \
1466 /* stack parameters */ \
1467 product_pd(intx, StackYellowPages, \
1468 "Number of yellow zone (recoverable overflows) pages of size " \
1469 "4KB. If pages are bigger yellow zone is aligned up.") \
1470 range(MIN_STACK_YELLOW_PAGES, (DEFAULT_STACK_YELLOW_PAGES+5)) \
1471 \
1472 product_pd(intx, StackRedPages, \
1473 "Number of red zone (unrecoverable overflows) pages of size " \
1474 "4KB. If pages are bigger red zone is aligned up.") \
1475 range(MIN_STACK_RED_PAGES, (DEFAULT_STACK_RED_PAGES+2)) \
1476 \
1477 product_pd(intx, StackReservedPages, \
1478 "Number of reserved zone (reserved to annotated methods) pages" \
1479 " of size 4KB. If pages are bigger reserved zone is aligned up.") \
1480 range(MIN_STACK_RESERVED_PAGES, (DEFAULT_STACK_RESERVED_PAGES+10))\
1481 \
1482 product(bool, RestrictReservedStack, true, \
1483 "Restrict @ReservedStackAccess to trusted classes") \
1484 \
1485 /* greater stack shadow pages can't generate instruction to bang stack */ \
1486 product_pd(intx, StackShadowPages, \
1487 "Number of shadow zone (for overflow checking) pages of size " \
1488 "4KB. If pages are bigger shadow zone is aligned up. " \
1489 "This should exceed the depth of the VM and native call stack.") \
1490 range(MIN_STACK_SHADOW_PAGES, (DEFAULT_STACK_SHADOW_PAGES+30)) \
1491 \
1492 product_pd(intx, ThreadStackSize, \
1493 "Thread Stack Size (in Kbytes)") \
1494 range(0, 1 * M) \
1495 \
1496 product_pd(intx, VMThreadStackSize, \
1497 "Non-Java Thread Stack Size (in Kbytes)") \
1498 range(0, max_intx/(1 * K)) \
1499 \
1500 product_pd(intx, CompilerThreadStackSize, \
1501 "Compiler Thread Stack Size (in Kbytes)") \
1502 range(0, max_intx/(1 * K)) \
1503 \
1504 develop_pd(size_t, JVMInvokeMethodSlack, \
1505 "Stack space (bytes) required for JVM_InvokeMethod to complete") \
1506 \
1507 /* code cache parameters */ \
1508 product_pd(uintx, CodeCacheSegmentSize, EXPERIMENTAL, \
1509 "Code cache segment size (in bytes) - smallest unit of " \
1510 "allocation") \
1511 range(1, 1024) \
1512 constraint(CodeCacheSegmentSizeConstraintFunc, AfterErgo) \
1513 \
1514 product_pd(intx, CodeEntryAlignment, EXPERIMENTAL, \
1515 "Code entry alignment for generated code (in bytes)") \
1516 constraint(CodeEntryAlignmentConstraintFunc, AfterErgo) \
1517 \
1518 product_pd(intx, OptoLoopAlignment, \
1519 "Align inner loops to zero relative to this modulus") \
1520 range(1, 128) \
1521 constraint(OptoLoopAlignmentConstraintFunc, AfterErgo) \
1522 \
1523 product_pd(uintx, InitialCodeCacheSize, \
1524 "Initial code cache size (in bytes)") \
1525 constraint(VMPageSizeConstraintFunc, AtParse) \
1526 \
1527 develop_pd(uintx, CodeCacheMinimumUseSpace, \
1528 "Minimum code cache size (in bytes) required to start VM.") \
1529 range(0, max_uintx) \
1530 \
1531 product(bool, SegmentedCodeCache, false, \
1532 "Use a segmented code cache") \
1533 \
1534 product_pd(uintx, ReservedCodeCacheSize, \
1535 "Reserved code cache size (in bytes) - maximum code cache size") \
1536 constraint(VMPageSizeConstraintFunc, AtParse) \
1537 \
1538 product_pd(uintx, NonProfiledCodeHeapSize, \
1539 "Size of code heap with non-profiled methods (in bytes)") \
1540 range(0, max_uintx) \
1541 \
1542 product_pd(uintx, ProfiledCodeHeapSize, \
1543 "Size of code heap with profiled methods (in bytes)") \
1544 range(0, max_uintx) \
1545 \
1546 product_pd(uintx, NonNMethodCodeHeapSize, \
1547 "Size of code heap with non-nmethods (in bytes)") \
1548 constraint(VMPageSizeConstraintFunc, AtParse) \
1549 \
1550 product_pd(uintx, CodeCacheExpansionSize, \
1551 "Code cache expansion size (in bytes)") \
1552 range(32*K, max_uintx) \
1553 \
1554 product_pd(uintx, CodeCacheMinBlockLength, DIAGNOSTIC, \
1555 "Minimum number of segments in a code cache block") \
1556 range(1, 100) \
1557 \
1558 develop(bool, ExitOnFullCodeCache, false, \
1559 "Exit the VM if we fill the code cache") \
1560 \
1561 product(bool, UseCodeCacheFlushing, true, \
1562 "Remove cold/old nmethods from the code cache") \
1563 \
1564 product(double, SweeperThreshold, 15.0, \
1565 "Threshold when a code cache unloading GC is invoked." \
1566 "Value is percentage of ReservedCodeCacheSize.") \
1567 range(0.0, 100.0) \
1568 \
1569 product(uintx, StartAggressiveSweepingAt, 10, \
1570 "Start aggressive sweeping if X[%] of the code cache is free." \
1571 "Segmented code cache: X[%] of the non-profiled heap." \
1572 "Non-segmented code cache: X[%] of the total code cache") \
1573 range(0, 100) \
1574 \
1575 /* interpreter debugging */ \
1576 develop(intx, BinarySwitchThreshold, 5, \
1577 "Minimal number of lookupswitch entries for rewriting to binary " \
1578 "switch") \
1579 \
1580 develop(intx, StopInterpreterAt, 0, \
1581 "Stop interpreter execution at specified bytecode number") \
1582 \
1583 develop(intx, TraceBytecodesAt, 0, \
1584 "Trace bytecodes starting with specified bytecode number") \
1585 \
1586 develop(intx, TraceBytecodesStopAt, 0, \
1587 "Stop bytecode tracing at the specified bytecode number") \
1588 \
1589 /* Priorities */ \
1590 product_pd(bool, UseThreadPriorities, "Use native thread priorities") \
1591 \
1592 product(int, ThreadPriorityPolicy, 0, \
1593 "0 : Normal. "\
1594 " VM chooses priorities that are appropriate for normal "\
1595 " applications. "\
1596 " On Windows applications are allowed to use higher native "\
1597 " priorities. However, with ThreadPriorityPolicy=0, VM will "\
1598 " not use the highest possible native priority, "\
1599 " THREAD_PRIORITY_TIME_CRITICAL, as it may interfere with "\
1600 " system threads. On Linux thread priorities are ignored "\
1601 " because the OS does not support static priority in "\
1602 " SCHED_OTHER scheduling class which is the only choice for "\
1603 " non-root, non-realtime applications. "\
1604 "1 : Aggressive. "\
1605 " Java thread priorities map over to the entire range of "\
1606 " native thread priorities. Higher Java thread priorities map "\
1607 " to higher native thread priorities. This policy should be "\
1608 " used with care, as sometimes it can cause performance "\
1609 " degradation in the application and/or the entire system. On "\
1610 " Linux/BSD/macOS this policy requires root privilege or an "\
1611 " extended capability.") \
1612 range(0, 1) \
1613 \
1614 product(bool, ThreadPriorityVerbose, false, \
1615 "Print priority changes") \
1616 \
1617 product(int, CompilerThreadPriority, -1, \
1618 "The native priority at which compiler threads should run " \
1619 "(-1 means no change)") \
1620 range(min_jint, max_jint) \
1621 \
1622 product(int, VMThreadPriority, -1, \
1623 "The native priority at which the VM thread should run " \
1624 "(-1 means no change)") \
1625 range(-1, 127) \
1626 \
1627 product(int, JavaPriority1_To_OSPriority, -1, \
1628 "Map Java priorities to OS priorities") \
1629 range(-1, 127) \
1630 \
1631 product(int, JavaPriority2_To_OSPriority, -1, \
1632 "Map Java priorities to OS priorities") \
1633 range(-1, 127) \
1634 \
1635 product(int, JavaPriority3_To_OSPriority, -1, \
1636 "Map Java priorities to OS priorities") \
1637 range(-1, 127) \
1638 \
1639 product(int, JavaPriority4_To_OSPriority, -1, \
1640 "Map Java priorities to OS priorities") \
1641 range(-1, 127) \
1642 \
1643 product(int, JavaPriority5_To_OSPriority, -1, \
1644 "Map Java priorities to OS priorities") \
1645 range(-1, 127) \
1646 \
1647 product(int, JavaPriority6_To_OSPriority, -1, \
1648 "Map Java priorities to OS priorities") \
1649 range(-1, 127) \
1650 \
1651 product(int, JavaPriority7_To_OSPriority, -1, \
1652 "Map Java priorities to OS priorities") \
1653 range(-1, 127) \
1654 \
1655 product(int, JavaPriority8_To_OSPriority, -1, \
1656 "Map Java priorities to OS priorities") \
1657 range(-1, 127) \
1658 \
1659 product(int, JavaPriority9_To_OSPriority, -1, \
1660 "Map Java priorities to OS priorities") \
1661 range(-1, 127) \
1662 \
1663 product(int, JavaPriority10_To_OSPriority,-1, \
1664 "Map Java priorities to OS priorities") \
1665 range(-1, 127) \
1666 \
1667 product(bool, UseCriticalJavaThreadPriority, false, EXPERIMENTAL, \
1668 "Java thread priority 10 maps to critical scheduling priority") \
1669 \
1670 product(bool, UseCriticalCompilerThreadPriority, false, EXPERIMENTAL, \
1671 "Compiler thread(s) run at critical scheduling priority") \
1672 \
1673 develop(intx, NewCodeParameter, 0, \
1674 "Testing Only: Create a dedicated integer parameter before " \
1675 "putback") \
1676 \
1677 /* new oopmap storage allocation */ \
1678 develop(intx, MinOopMapAllocation, 8, \
1679 "Minimum number of OopMap entries in an OopMapSet") \
1680 \
1681 /* recompilation */ \
1682 product_pd(intx, CompileThreshold, \
1683 "number of interpreted method invocations before (re-)compiling") \
1684 constraint(CompileThresholdConstraintFunc, AfterErgo) \
1685 \
1686 product_pd(bool, TieredCompilation, \
1687 "Enable tiered compilation") \
1688 \
1689 /* Properties for Java libraries */ \
1690 \
1691 product(uint64_t, MaxDirectMemorySize, 0, \
1692 "Maximum total size of NIO direct-buffer allocations. " \
1693 "Ignored if not explicitly set.") \
1694 range(0, max_jlong) \
1695 \
1696 /* Flags used for temporary code during development */ \
1697 \
1698 product(bool, UseNewCode, false, DIAGNOSTIC, \
1699 "Testing Only: Use the new version while testing") \
1700 \
1701 product(bool, UseNewCode2, false, DIAGNOSTIC, \
1702 "Testing Only: Use the new version while testing") \
1703 \
1704 product(bool, UseNewCode3, false, DIAGNOSTIC, \
1705 "Testing Only: Use the new version while testing") \
1706 \
1707 develop(bool, UseDebuggerErgo, false, \
1708 "Debugging Only: Adjust the VM to be more debugger-friendly. " \
1709 "Turns on the other UseDebuggerErgo* flags") \
1710 \
1711 develop(bool, UseDebuggerErgo1, false, \
1712 "Debugging Only: Enable workarounds for debugger induced " \
1713 "os::processor_id() >= os::processor_count() problems") \
1714 \
1715 develop(bool, UseDebuggerErgo2, false, \
1716 "Debugging Only: Limit the number of spawned JVM threads") \
1717 \
1718 develop(bool, EnableJVMTIStackDepthAsserts, true, \
1719 "Enable JVMTI asserts related to stack depth checks") \
1720 \
1721 /* flags for performance data collection */ \
1722 \
1723 product(bool, UsePerfData, true, \
1724 "Flag to disable jvmstat instrumentation for performance testing "\
1725 "and problem isolation purposes") \
1726 \
1727 product(bool, PerfDataSaveToFile, false, \
1728 "Save PerfData memory to hsperfdata_<pid> file on exit") \
1729 \
1730 product(ccstr, PerfDataSaveFile, nullptr, \
1731 "Save PerfData memory to the specified absolute pathname. " \
1732 "The string %p in the file name (if present) " \
1733 "will be replaced by pid") \
1734 \
1735 product(int, PerfDataSamplingInterval, 50, \
1736 "Data sampling interval (in milliseconds)") \
1737 range(PeriodicTask::min_interval, max_jint) \
1738 constraint(PerfDataSamplingIntervalFunc, AfterErgo) \
1739 \
1740 product(bool, PerfDisableSharedMem, false, \
1741 "Store performance data in standard memory") \
1742 \
1743 product(int, PerfDataMemorySize, 64*K, \
1744 "Size of performance data memory region. Will be rounded " \
1745 "up to a multiple of the native os page size.") \
1746 range(128, 32*64*K) \
1747 \
1748 product(int, PerfMaxStringConstLength, 1024, \
1749 "Maximum PerfStringConstant string length before truncation") \
1750 range(32, 32*K) \
1751 \
1752 product(bool, PerfAllowAtExitRegistration, false, \
1753 "Allow registration of atexit() methods") \
1754 \
1755 product(bool, PerfBypassFileSystemCheck, false, \
1756 "Bypass Win32 file system criteria checks (Windows Only)") \
1757 \
1758 product(int, UnguardOnExecutionViolation, 0, \
1759 "Unguard page and retry on no-execute fault (Win32 only) " \
1760 "0=off, 1=conservative, 2=aggressive") \
1761 range(0, 2) \
1762 \
1763 /* Serviceability Support */ \
1764 \
1765 product(bool, ManagementServer, false, \
1766 "Create JMX Management Server") \
1767 \
1768 product(bool, DisableAttachMechanism, false, \
1769 "Disable mechanism that allows tools to attach to this VM") \
1770 \
1771 product(bool, StartAttachListener, false, \
1772 "Always start Attach Listener at VM startup") \
1773 \
1774 product(bool, EnableDynamicAgentLoading, true, \
1775 "Allow tools to load agents with the attach mechanism") \
1776 \
1777 product(bool, PrintConcurrentLocks, false, MANAGEABLE, \
1778 "Print java.util.concurrent locks in thread dump") \
1779 \
1780 product(bool, PrintMethodHandleStubs, false, DIAGNOSTIC, \
1781 "Print generated stub code for method handles") \
1782 \
1783 product(bool, VerifyMethodHandles, trueInDebug, DIAGNOSTIC, \
1784 "perform extra checks when constructing method handles") \
1785 \
1786 product(bool, ShowHiddenFrames, false, DIAGNOSTIC, \
1787 "show method handle implementation frames (usually hidden)") \
1788 \
1789 product(bool, ShowCarrierFrames, false, DIAGNOSTIC, \
1790 "show virtual threads' carrier frames in exceptions") \
1791 \
1792 product(bool, TrustFinalNonStaticFields, false, EXPERIMENTAL, \
1793 "trust final non-static declarations for constant folding") \
1794 \
1795 product(bool, FoldStableValues, true, DIAGNOSTIC, \
1796 "Optimize loads from stable fields (marked w/ @Stable)") \
1797 \
1798 product(int, UseBootstrapCallInfo, 1, DIAGNOSTIC, \
1799 "0: when resolving InDy or ConDy, force all BSM arguments to be " \
1800 "resolved before the bootstrap method is called; 1: when a BSM " \
1801 "that may accept a BootstrapCallInfo is detected, use that API " \
1802 "to pass BSM arguments, which allows the BSM to delay their " \
1803 "resolution; 2+: stress test the BCI API by calling more BSMs " \
1804 "via that API, instead of with the eagerly-resolved array.") \
1805 \
1806 product(bool, PauseAtStartup, false, DIAGNOSTIC, \
1807 "Causes the VM to pause at startup time and wait for the pause " \
1808 "file to be removed (default: ./vm.paused.<pid>)") \
1809 \
1810 product(ccstr, PauseAtStartupFile, nullptr, DIAGNOSTIC, \
1811 "The file to create and for whose removal to await when pausing " \
1812 "at startup. (default: ./vm.paused.<pid>)") \
1813 \
1814 product(bool, PauseAtExit, false, DIAGNOSTIC, \
1815 "Pause and wait for keypress on exit if a debugger is attached") \
1816 \
1817 product(bool, DTraceMethodProbes, false, \
1818 "Enable dtrace tool probes for method-entry and method-exit") \
1819 \
1820 product(bool, DTraceAllocProbes, false, \
1821 "Enable dtrace tool probes for object allocation") \
1822 \
1823 product(bool, DTraceMonitorProbes, false, \
1824 "Enable dtrace tool probes for monitor events") \
1825 \
1826 product(bool, RelaxAccessControlCheck, false, \
1827 "Relax the access control checks in the verifier") \
1828 \
1829 product(uintx, StringTableSize, defaultStringTableSize, \
1830 "Number of buckets in the interned String table " \
1831 "(will be rounded to nearest higher power of 2)") \
1832 range(minimumStringTableSize, 16777216ul /* 2^24 */) \
1833 \
1834 product(uintx, SymbolTableSize, defaultSymbolTableSize, EXPERIMENTAL, \
1835 "Number of buckets in the JVM internal Symbol table") \
1836 range(minimumSymbolTableSize, 16777216ul /* 2^24 */) \
1837 \
1838 product(bool, UseStringDeduplication, false, \
1839 "Use string deduplication") \
1840 \
1841 product(uint, StringDeduplicationAgeThreshold, 3, \
1842 "A string must reach this age (or be promoted to an old region) " \
1843 "to be considered for deduplication") \
1844 range(1, markWord::max_age) \
1845 \
1846 product(size_t, StringDeduplicationInitialTableSize, 500, EXPERIMENTAL, \
1847 "Approximate initial number of buckets in the table") \
1848 range(1, 1 * G) \
1849 \
1850 product(double, StringDeduplicationGrowTableLoad, 14.0, EXPERIMENTAL, \
1851 "Entries per bucket above which the table should be expanded") \
1852 range(0.1, 1000.0) \
1853 \
1854 product(double, StringDeduplicationShrinkTableLoad, 1.0, EXPERIMENTAL, \
1855 "Entries per bucket below which the table should be shrunk") \
1856 range(0.01, 100.0) \
1857 \
1858 product(double, StringDeduplicationTargetTableLoad, 7.0, EXPERIMENTAL, \
1859 "Desired entries per bucket when resizing the table") \
1860 range(0.01, 1000.0) \
1861 \
1862 product(size_t, StringDeduplicationCleanupDeadMinimum, 100, EXPERIMENTAL, \
1863 "Minimum number of dead table entries for cleaning the table") \
1864 \
1865 product(int, StringDeduplicationCleanupDeadPercent, 5, EXPERIMENTAL, \
1866 "Minimum percentage of dead table entries for cleaning the table") \
1867 range(1, 100) \
1868 \
1869 product(bool, StringDeduplicationResizeALot, false, DIAGNOSTIC, \
1870 "Force more frequent table resizing") \
1871 \
1872 product(uint64_t, StringDeduplicationHashSeed, 0, DIAGNOSTIC, \
1873 "Seed for the table hashing function; 0 requests computed seed") \
1874 \
1875 product(bool, WhiteBoxAPI, false, DIAGNOSTIC, \
1876 "Enable internal testing APIs") \
1877 \
1878 product(bool, AlwaysAtomicAccesses, false, EXPERIMENTAL, \
1879 "Accesses to all variables should always be atomic") \
1880 \
1881 product(bool, UseUnalignedAccesses, false, DIAGNOSTIC, \
1882 "Use unaligned memory accesses in Unsafe") \
1883 \
1884 product_pd(bool, PreserveFramePointer, \
1885 "Use the FP register for holding the frame pointer " \
1886 "and not as a general purpose register.") \
1887 \
1888 product(size_t, AsyncLogBufferSize, 2*M, \
1889 "Memory budget (in bytes) for the buffer of Asynchronous " \
1890 "Logging (-Xlog:async).") \
1891 range(100*K, 50*M) \
1892 \
1893 product(bool, CheckIntrinsics, true, DIAGNOSTIC, \
1894 "When a class C is loaded, check that " \
1895 "(1) all intrinsics defined by the VM for class C are present "\
1896 "in the loaded class file and are marked with the " \
1897 "@IntrinsicCandidate annotation, that " \
1898 "(2) there is an intrinsic registered for all loaded methods " \
1899 "that are annotated with the @IntrinsicCandidate annotation, " \
1900 "and that " \
1901 "(3) no orphan methods exist for class C (i.e., methods for " \
1902 "which the VM declares an intrinsic but that are not declared "\
1903 "in the loaded class C. " \
1904 "Check (3) is available only in debug builds.") \
1905 \
1906 product_pd(intx, InitArrayShortSize, DIAGNOSTIC, \
1907 "Threshold small size (in bytes) for clearing arrays. " \
1908 "Anything this size or smaller may get converted to discrete " \
1909 "scalar stores.") \
1910 range(0, max_intx) \
1911 constraint(InitArrayShortSizeConstraintFunc, AfterErgo) \
1912 \
1913 product(ccstr, AllocateHeapAt, nullptr, \
1914 "Path to the directory where a temporary file will be created " \
1915 "to use as the backing store for Java Heap.") \
1916 \
1917 product_pd(bool, VMContinuations, EXPERIMENTAL, \
1918 "Enable VM continuations support") \
1919 \
1920 develop(bool, LoomDeoptAfterThaw, false, \
1921 "Deopt stack after thaw") \
1922 \
1923 develop(bool, LoomVerifyAfterThaw, false, \
1924 "Verify stack after thaw") \
1925 \
1926 develop(bool, VerifyContinuations, false, \
1927 "Verify continuation consistency") \
1928 \
1929 develop(bool, UseContinuationFastPath, true, \
1930 "Use fast-path frame walking in continuations") \
1931 \
1932 develop(int, VerifyMetaspaceInterval, DEBUG_ONLY(500) NOT_DEBUG(0), \
1933 "Run periodic metaspace verifications (0 - none, " \
1934 "1 - always, >1 every nth interval)") \
1935 \
1936 product(bool, ShowRegistersOnAssert, true, DIAGNOSTIC, \
1937 "On internal errors, include registers in error report.") \
1938 \
1939 product(bool, UseSwitchProfiling, true, DIAGNOSTIC, \
1940 "leverage profiling for table/lookup switch") \
1941 \
1942 develop(bool, TraceMemoryWriteback, false, \
1943 "Trace memory writeback operations") \
1944 \
1945 JFR_ONLY(product(bool, FlightRecorder, false, \
1946 "(Deprecated) Enable Flight Recorder")) \
1947 \
1948 JFR_ONLY(product(ccstr, FlightRecorderOptions, nullptr, \
1949 "Flight Recorder options")) \
1950 \
1951 JFR_ONLY(product(ccstr, StartFlightRecording, nullptr, \
1952 "Start flight recording with options")) \
1953 \
1954 product(bool, UseFastUnorderedTimeStamps, false, EXPERIMENTAL, \
1955 "Use platform unstable time where supported for timestamps only") \
1956 \
1957 product(bool, DeoptimizeNMethodBarriersALot, false, DIAGNOSTIC, \
1958 "Make nmethod barriers deoptimise a lot.") \
1959 \
1960 develop(bool, VerifyCrossModifyFence, \
1961 false AARCH64_ONLY(DEBUG_ONLY(||true)), \
1962 "Mark all threads after a safepoint, and clear on a modify " \
1963 "fence. Add cleanliness checks.") \
1964 \
1965 product(int, LockingMode, LM_LIGHTWEIGHT, \
1966 "(Deprecated) Select locking mode: " \
1967 "0: (Deprecated) monitors only (LM_MONITOR), " \
1968 "1: (Deprecated) monitors & legacy stack-locking (LM_LEGACY), " \
1969 "2: monitors & new lightweight locking (LM_LIGHTWEIGHT, default)") \
1970 range(0, 2) \
1971 \
1972 product(bool, UseObjectMonitorTable, false, DIAGNOSTIC, \
1973 "With Lightweight Locking mode, use a table to record inflated " \
1974 "monitors rather than the first word of the object.") \
1975 \
1976 product(int, LightweightFastLockingSpins, 13, DIAGNOSTIC, \
1977 "Specifies the number of times lightweight fast locking will " \
1978 "attempt to CAS the markWord before inflating. Between each " \
1979 "CAS it will spin for exponentially more time, resulting in " \
1980 "a total number of spins on the order of O(2^value)") \
1981 range(1, 30) \
1982 \
1983 product(uint, TrimNativeHeapInterval, 0, \
1984 "Interval, in ms, at which the JVM will trim the native heap if " \
1985 "the platform supports that. Lower values will reclaim memory " \
1986 "more eagerly at the cost of higher overhead. A value of 0 " \
1987 "(default) disables native heap trimming.") \
1988 range(0, UINT_MAX) \
1989 \
1990 product(bool, ProfileVMLocks, false, DIAGNOSTIC, \
1991 "Profile VM locks usage on main thread") \
1992 \
1993 product(bool, ProfileVMCalls, false, DIAGNOSTIC, \
1994 "Profile VM calls on main thread") \
1995 \
1996 product(bool, ProfileVMOps, true, DIAGNOSTIC, \
1997 "Profile VM operations on main thread") \
1998 \
1999 product(bool, ProfileRuntimeCalls, false, DIAGNOSTIC, \
2000 "Profile calls into VM runtime on main thread") \
2001 \
2002 develop(bool, SimulateFullAddressSpace, false, \
2003 "Simulates a very populated, fragmented address space; no " \
2004 "targeted reservations will succeed.") \
2005 \
2006 product(bool, ProfileExceptionHandlers, true, \
2007 "Profile exception handlers") \
2008 \
2009 product(bool, AlwaysRecordEvolDependencies, true, EXPERIMENTAL, \
2010 "Unconditionally record nmethod dependencies on class " \
2011 "rewriting/transformation independently of the JVMTI " \
2012 "can_{retransform/redefine}_classes capabilities.") \
2013 \
2014 product(bool, TraceThreadTime, false, \
2015 "Enable tracing of thread time in Perf counters") \
2016 \
2017 product(bool, UseSecondarySupersCache, true, DIAGNOSTIC, \
2018 "Use secondary supers cache during subtype checks.") \
2019 \
2020 product(bool, UseSecondarySupersTable, false, DIAGNOSTIC, \
2021 "Use hash table to lookup secondary supers.") \
2022 \
2023 product(bool, VerifySecondarySupers, false, DIAGNOSTIC, \
2024 "Check that linear and hashed secondary lookups return the same result.") \
2025 \
2026 product(bool, StressSecondarySupers, false, DIAGNOSTIC, \
2027 "Use a terrible hash function in order to generate many collisions.") \
2028 \
2029 product(bool, UseThreadsLockThrottleLock, true, DIAGNOSTIC, \
2030 "Use an extra lock during Thread start and exit to alleviate" \
2031 "contention on Threads_lock.") \
2032
2033
2034 // end of RUNTIME_FLAGS
2035
2036 DECLARE_FLAGS(LP64_RUNTIME_FLAGS)
2037 DECLARE_ARCH_FLAGS(ARCH_FLAGS)
2038 DECLARE_FLAGS(RUNTIME_FLAGS)
2039 DECLARE_FLAGS(RUNTIME_OS_FLAGS)
2040
2041 #endif // SHARE_RUNTIME_GLOBALS_HPP