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 *
15 * You should have received a copy of the GNU General Public License version
16 * 2 along with this work; if not, write to the Free Software Foundation,
17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
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20 * or visit www.oracle.com if you need additional information or have any
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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 product(bool, UseCompactObjectHeaders, false, EXPERIMENTAL, \
132 "Use compact 64-bit object headers in 64-bit VM") \
133 \
134 develop(int, TinyClassPointerShift, 0, "") \
135 \
136 product(int, ObjectAlignmentInBytes, 8, \
137 "Default object alignment in bytes, 8 is minimum") \
138 range(8, 256) \
139 constraint(ObjectAlignmentInBytesConstraintFunc, AtParse)
140
141 #else
142 // !_LP64
143
144 #define LP64_RUNTIME_FLAGS(develop, \
145 develop_pd, \
146 product, \
147 product_pd, \
148 range, \
149 constraint)
150 const bool UseCompressedOops = false;
151 const bool UseCompressedClassPointers = false;
152 const bool UseCompactObjectHeaders = false;
153 const int ObjectAlignmentInBytes = 8;
154
155 #endif // _LP64
156
157 #define RUNTIME_FLAGS(develop, \
158 develop_pd, \
159 product, \
160 product_pd, \
161 range, \
162 constraint) \
163 \
164 develop(bool, CheckCompressedOops, true, \
165 "Generate checks in encoding/decoding code in debug VM") \
166 \
167 product(uintx, HeapSearchSteps, 3 PPC64_ONLY(+17), \
168 "Heap allocation steps through preferred address regions to find" \
169 " where it can allocate the heap. Number of steps to take per " \
170 "region.") \
171 range(1, max_uintx) \
172 \
173 product(uint, HandshakeTimeout, 0, DIAGNOSTIC, \
174 "If nonzero set a timeout in milliseconds for handshakes") \
175 \
176 product(bool, AlwaysSafeConstructors, false, EXPERIMENTAL, \
177 "Force safe construction, as if all fields are final.") \
178 \
179 product(bool, UnlockDiagnosticVMOptions, trueInDebug, DIAGNOSTIC, \
180 "Enable normal processing of flags relating to field diagnostics")\
181 \
182 product(bool, UnlockExperimentalVMOptions, false, EXPERIMENTAL, \
183 "Enable normal processing of flags relating to experimental " \
184 "features") \
185 \
186 product(bool, JavaMonitorsInStackTrace, true, \
187 "Print information about Java monitor locks when the stacks are " \
188 "dumped") \
189 \
190 product_pd(bool, UseLargePages, \
191 "Use large page memory") \
192 \
193 product_pd(bool, UseLargePagesIndividualAllocation, \
194 "Allocate large pages individually for better affinity") \
195 \
196 develop(bool, LargePagesIndividualAllocationInjectError, false, \
197 "Fail large pages individual allocation") \
198 \
199 product(bool, UseNUMA, false, \
200 "Use NUMA if available") \
201 \
202 product(bool, UseNUMAInterleaving, false, \
203 "Interleave memory across NUMA nodes if available") \
204 \
205 product(size_t, NUMAInterleaveGranularity, 2*M, \
206 "Granularity to use for NUMA interleaving on Windows OS") \
207 constraint(NUMAInterleaveGranularityConstraintFunc, AtParse) \
208 \
209 product(uintx, NUMAChunkResizeWeight, 20, \
210 "Percentage (0-100) used to weight the current sample when " \
211 "computing exponentially decaying average for " \
212 "AdaptiveNUMAChunkSizing") \
213 range(0, 100) \
214 \
215 product(size_t, NUMASpaceResizeRate, 1*G, \
216 "Do not reallocate more than this amount per collection") \
217 range(0, max_uintx) \
218 \
219 product(bool, UseAdaptiveNUMAChunkSizing, true, \
220 "Enable adaptive chunk sizing for NUMA") \
221 \
222 product(bool, NUMAStats, false, \
223 "Print NUMA stats in detailed heap information") \
224 \
225 product(bool, UseAES, false, \
226 "Control whether AES instructions are used when available") \
227 \
228 product(bool, UseFMA, false, \
229 "Control whether FMA instructions are used when available") \
230 \
231 product(bool, UseSHA, false, \
232 "Control whether SHA instructions are used when available") \
233 \
234 product(bool, UseGHASHIntrinsics, false, DIAGNOSTIC, \
235 "Use intrinsics for GHASH versions of crypto") \
236 \
237 product(bool, UseBASE64Intrinsics, false, \
238 "Use intrinsics for java.util.Base64") \
239 \
240 product(bool, UsePoly1305Intrinsics, false, DIAGNOSTIC, \
241 "Use intrinsics for sun.security.util.math.intpoly") \
242 \
243 product(size_t, LargePageSizeInBytes, 0, \
244 "Maximum large page size used (0 will use the default large " \
245 "page size for the environment as the maximum)") \
246 range(0, max_uintx) \
247 \
248 product(size_t, LargePageHeapSizeThreshold, 128*M, \
249 "Use large pages if maximum heap is at least this big") \
250 range(0, max_uintx) \
251 \
252 product(bool, ForceTimeHighResolution, false, \
253 "Using high time resolution (for Win32 only)") \
254 \
255 develop(bool, TracePcPatching, false, \
256 "Trace usage of frame::patch_pc") \
257 \
258 develop(bool, TraceRelocator, false, \
259 "Trace the bytecode relocator") \
260 \
261 \
262 product(bool, SafepointALot, false, DIAGNOSTIC, \
263 "Generate a lot of safepoints. This works with " \
264 "GuaranteedSafepointInterval") \
265 \
266 product(bool, HandshakeALot, false, DIAGNOSTIC, \
267 "Generate a lot of handshakes. This works with " \
268 "GuaranteedSafepointInterval") \
269 \
270 product_pd(bool, BackgroundCompilation, \
271 "A thread requesting compilation is not blocked during " \
272 "compilation") \
273 \
274 product(bool, MethodFlushing, true, \
275 "Reclamation of compiled methods") \
276 \
277 develop(bool, VerifyStack, false, \
278 "Verify stack of each thread when it is entering a runtime call") \
279 \
280 product(bool, ForceUnreachable, false, DIAGNOSTIC, \
281 "Make all non code cache addresses to be unreachable by " \
282 "forcing use of 64bit literal fixups") \
283 \
284 develop(bool, TraceDerivedPointers, false, \
285 "Trace traversal of derived pointers on stack") \
286 \
287 develop(bool, TraceCodeBlobStacks, false, \
288 "Trace stack-walk of codeblobs") \
289 \
290 develop(bool, PrintRewrites, false, \
291 "Print methods that are being rewritten") \
292 \
293 product(bool, UseInlineCaches, true, \
294 "Use Inline Caches for virtual calls ") \
295 \
296 product(size_t, InlineCacheBufferSize, 10*K, EXPERIMENTAL, \
297 "InlineCacheBuffer size") \
298 \
299 product(bool, InlineArrayCopy, true, DIAGNOSTIC, \
300 "Inline arraycopy native that is known to be part of " \
301 "base library DLL") \
302 \
303 product(bool, InlineObjectHash, true, DIAGNOSTIC, \
304 "Inline Object::hashCode() native that is known to be part " \
305 "of base library DLL") \
306 \
307 product(bool, InlineNatives, true, DIAGNOSTIC, \
308 "Inline natives that are known to be part of base library DLL") \
309 \
310 product(bool, InlineMathNatives, true, DIAGNOSTIC, \
311 "Inline SinD, CosD, etc.") \
312 \
313 product(bool, InlineClassNatives, true, DIAGNOSTIC, \
314 "Inline Class.isInstance, etc") \
315 \
316 product(bool, InlineThreadNatives, true, DIAGNOSTIC, \
317 "Inline Thread.currentThread, etc") \
318 \
319 product(bool, InlineUnsafeOps, true, DIAGNOSTIC, \
320 "Inline memory ops (native methods) from Unsafe") \
321 \
322 product(bool, UseAESIntrinsics, false, DIAGNOSTIC, \
323 "Use intrinsics for AES versions of crypto") \
324 \
325 product(bool, UseAESCTRIntrinsics, false, DIAGNOSTIC, \
326 "Use intrinsics for the paralleled version of AES/CTR crypto") \
327 \
328 product(bool, UseChaCha20Intrinsics, false, DIAGNOSTIC, \
329 "Use intrinsics for the vectorized version of ChaCha20") \
330 \
331 product(bool, UseMD5Intrinsics, false, DIAGNOSTIC, \
332 "Use intrinsics for MD5 crypto hash function") \
333 \
334 product(bool, UseSHA1Intrinsics, false, DIAGNOSTIC, \
335 "Use intrinsics for SHA-1 crypto hash function. " \
336 "Requires that UseSHA is enabled.") \
337 \
338 product(bool, UseSHA256Intrinsics, false, DIAGNOSTIC, \
339 "Use intrinsics for SHA-224 and SHA-256 crypto hash functions. " \
340 "Requires that UseSHA is enabled.") \
341 \
342 product(bool, UseSHA512Intrinsics, false, DIAGNOSTIC, \
343 "Use intrinsics for SHA-384 and SHA-512 crypto hash functions. " \
344 "Requires that UseSHA is enabled.") \
345 \
346 product(bool, UseSHA3Intrinsics, false, DIAGNOSTIC, \
347 "Use intrinsics for SHA3 crypto hash function. " \
348 "Requires that UseSHA is enabled.") \
349 \
350 product(bool, UseCRC32Intrinsics, false, DIAGNOSTIC, \
351 "use intrinsics for java.util.zip.CRC32") \
352 \
353 product(bool, UseCRC32CIntrinsics, false, DIAGNOSTIC, \
354 "use intrinsics for java.util.zip.CRC32C") \
355 \
356 product(bool, UseAdler32Intrinsics, false, DIAGNOSTIC, \
357 "use intrinsics for java.util.zip.Adler32") \
358 \
359 product(bool, UseVectorizedMismatchIntrinsic, false, DIAGNOSTIC, \
360 "Enables intrinsification of ArraysSupport.vectorizedMismatch()") \
361 \
362 product(bool, UseVectorizedHashCodeIntrinsic, false, DIAGNOSTIC, \
363 "Enables intrinsification of ArraysSupport.vectorizedHashCode()") \
364 \
365 product(bool, UseCopySignIntrinsic, false, DIAGNOSTIC, \
366 "Enables intrinsification of Math.copySign") \
367 \
368 product(bool, UseSignumIntrinsic, false, DIAGNOSTIC, \
369 "Enables intrinsification of Math.signum") \
370 \
371 product_pd(bool, DelayCompilerStubsGeneration, DIAGNOSTIC, \
372 "Use Compiler thread for compiler's stubs generation") \
373 \
374 product(ccstrlist, DisableIntrinsic, "", DIAGNOSTIC, \
375 "do not expand intrinsics whose (internal) names appear here") \
376 constraint(DisableIntrinsicConstraintFunc,AfterErgo) \
377 \
378 product(ccstrlist, ControlIntrinsic, "", DIAGNOSTIC, \
379 "Control intrinsics using a list of +/- (internal) names, " \
380 "separated by commas") \
381 constraint(ControlIntrinsicConstraintFunc,AfterErgo) \
382 \
383 develop(bool, TraceCallFixup, false, \
384 "Trace all call fixups") \
385 \
386 develop(bool, DeoptimizeALot, false, \
387 "Deoptimize at every exit from the runtime system") \
388 \
389 develop(ccstrlist, DeoptimizeOnlyAt, "", \
390 "A comma separated list of bcis to deoptimize at") \
391 \
392 develop(bool, DeoptimizeRandom, false, \
393 "Deoptimize random frames on random exit from the runtime system")\
394 \
395 develop(bool, ZombieALot, false, \
396 "Create non-entrant nmethods at exit from the runtime system") \
397 \
398 develop(bool, WalkStackALot, false, \
399 "Trace stack (no print) at every exit from the runtime system") \
400 \
401 develop(bool, DeoptimizeObjectsALot, false, \
402 "For testing purposes concurrent threads revert optimizations " \
403 "based on escape analysis at intervals given with " \
404 "DeoptimizeObjectsALotInterval=n. The thread count is given " \
405 "with DeoptimizeObjectsALotThreadCountSingle and " \
406 "DeoptimizeObjectsALotThreadCountAll.") \
407 \
408 develop(uint64_t, DeoptimizeObjectsALotInterval, 5, \
409 "Interval for DeoptimizeObjectsALot.") \
410 range(0, max_jlong) \
411 \
412 develop(int, DeoptimizeObjectsALotThreadCountSingle, 1, \
413 "The number of threads that revert optimizations based on " \
414 "escape analysis for a single thread if DeoptimizeObjectsALot " \
415 "is enabled. The target thread is selected round robin." ) \
416 range(0, max_jint) \
417 \
418 develop(int, DeoptimizeObjectsALotThreadCountAll, 1, \
419 "The number of threads that revert optimizations based on " \
420 "escape analysis for all threads if DeoptimizeObjectsALot " \
421 "is enabled." ) \
422 range(0, max_jint) \
423 \
424 develop(bool, VerifyLastFrame, false, \
425 "Verify oops on last frame on entry to VM") \
426 \
427 product(bool, SafepointTimeout, false, \
428 "Time out and warn or fail after SafepointTimeoutDelay " \
429 "milliseconds if failed to reach safepoint") \
430 \
431 product(bool, AbortVMOnSafepointTimeout, false, DIAGNOSTIC, \
432 "Abort upon failure to reach safepoint (see SafepointTimeout)") \
433 \
434 product(uint64_t, AbortVMOnSafepointTimeoutDelay, 0, DIAGNOSTIC, \
435 "Delay in milliseconds for option AbortVMOnSafepointTimeout") \
436 range(0, max_jlong) \
437 \
438 product(bool, AbortVMOnVMOperationTimeout, false, DIAGNOSTIC, \
439 "Abort upon failure to complete VM operation promptly") \
440 \
441 product(intx, AbortVMOnVMOperationTimeoutDelay, 1000, DIAGNOSTIC, \
442 "Delay in milliseconds for option AbortVMOnVMOperationTimeout") \
443 range(0, max_intx) \
444 \
445 product(bool, MaxFDLimit, true, \
446 "Bump the number of file descriptors to maximum (Unix only)") \
447 \
448 product(bool, LogEvents, true, DIAGNOSTIC, \
449 "Enable the various ring buffer event logs") \
450 \
451 product(int, LogEventsBufferEntries, 20, DIAGNOSTIC, \
452 "Number of ring buffer event logs") \
453 range(1, NOT_LP64(1*K) LP64_ONLY(1*M)) \
454 \
455 product(bool, BytecodeVerificationRemote, true, DIAGNOSTIC, \
456 "Enable the Java bytecode verifier for remote classes") \
457 \
458 product(bool, BytecodeVerificationLocal, false, DIAGNOSTIC, \
459 "Enable the Java bytecode verifier for local classes") \
460 \
461 develop(bool, VerifyStackAtCalls, false, \
462 "Verify that the stack pointer is unchanged after calls") \
463 \
464 develop(bool, TraceJavaAssertions, false, \
465 "Trace java language assertions") \
466 \
467 develop(bool, VerifyCodeCache, false, \
468 "Verify code cache on memory allocation/deallocation") \
469 \
470 develop(bool, ZapResourceArea, trueInDebug, \
471 "Zap freed resource/arena space") \
472 \
473 develop(bool, ZapVMHandleArea, trueInDebug, \
474 "Zap freed VM handle space") \
475 \
476 develop(bool, ZapStackSegments, trueInDebug, \
477 "Zap allocated/freed stack segments") \
478 \
479 develop(bool, ZapUnusedHeapArea, trueInDebug, \
480 "Zap unused heap space") \
481 \
482 develop(bool, CheckZapUnusedHeapArea, false, \
483 "Check zapping of unused heap space") \
484 \
485 develop(bool, ZapFillerObjects, trueInDebug, \
486 "Zap filler objects") \
487 \
488 develop(bool, ZapTLAB, trueInDebug, \
489 "Zap allocated TLABs") \
490 \
491 product(bool, ExecutingUnitTests, false, \
492 "Whether the JVM is running unit tests or not") \
493 \
494 develop(uint, ErrorHandlerTest, 0, \
495 "If > 0, provokes an error after VM initialization; the value " \
496 "determines which error to provoke. See controlled_crash() " \
497 "in vmError.cpp.") \
498 range(0, 17) \
499 \
500 develop(uint, TestCrashInErrorHandler, 0, \
501 "If > 0, provokes an error inside VM error handler (a secondary " \
502 "crash). see controlled_crash() in vmError.cpp") \
503 range(0, 17) \
504 \
505 develop(bool, TestSafeFetchInErrorHandler, false , \
506 "If true, tests SafeFetch inside error handler.") \
507 \
508 develop(bool, TestUnresponsiveErrorHandler, false, \
509 "If true, simulates an unresponsive error handler.") \
510 \
511 develop(bool, Verbose, false, \
512 "Print additional debugging information from other modes") \
513 \
514 develop(bool, PrintMiscellaneous, false, \
515 "Print uncategorized debugging information (requires +Verbose)") \
516 \
517 develop(bool, WizardMode, false, \
518 "Print much more debugging information") \
519 \
520 product(bool, ShowMessageBoxOnError, false, \
521 "Keep process alive on VM fatal error") \
522 \
523 product(bool, CreateCoredumpOnCrash, true, \
524 "Create core/mini dump on VM fatal error") \
525 \
526 product(uint64_t, ErrorLogTimeout, 2 * 60, \
527 "Timeout, in seconds, to limit the time spent on writing an " \
528 "error log in case of a crash.") \
529 range(0, (uint64_t)max_jlong/1000) \
530 \
531 product(bool, ErrorLogSecondaryErrorDetails, false, DIAGNOSTIC, \
532 "If enabled, show details on secondary crashes in the error log") \
533 \
534 develop(intx, TraceDwarfLevel, 0, \
535 "Debug levels for the dwarf parser") \
536 range(0, 4) \
537 \
538 product(bool, SuppressFatalErrorMessage, false, \
539 "Report NO fatal error message (avoid deadlock)") \
540 \
541 product(ccstrlist, OnError, "", \
542 "Run user-defined commands on fatal error; see VMError.cpp " \
543 "for examples") \
544 \
545 product(ccstrlist, OnOutOfMemoryError, "", \
546 "Run user-defined commands on first java.lang.OutOfMemoryError " \
547 "thrown from JVM") \
548 \
549 product(bool, HeapDumpBeforeFullGC, false, MANAGEABLE, \
550 "Dump heap to file before any major stop-the-world GC " \
551 "(also see FullGCHeapDumpLimit)") \
552 \
553 product(bool, HeapDumpAfterFullGC, false, MANAGEABLE, \
554 "Dump heap to file after any major stop-the-world GC " \
555 "(also see FullGCHeapDumpLimit)") \
556 \
557 product(uint, FullGCHeapDumpLimit, 0, MANAGEABLE, \
558 "Limit the number of heap dumps triggered by " \
559 "HeapDumpBeforeFullGC or HeapDumpAfterFullGC " \
560 "(0 means no limit)") \
561 \
562 product(bool, HeapDumpOnOutOfMemoryError, false, MANAGEABLE, \
563 "Dump heap to file when java.lang.OutOfMemoryError is thrown " \
564 "from JVM") \
565 \
566 product(ccstr, HeapDumpPath, nullptr, MANAGEABLE, \
567 "When HeapDumpOnOutOfMemoryError is on, the path (filename or " \
568 "directory) of the dump file (defaults to java_pid<pid>.hprof " \
569 "in the working directory)") \
570 \
571 product(int, HeapDumpGzipLevel, 0, MANAGEABLE, \
572 "When HeapDumpOnOutOfMemoryError is on, the gzip compression " \
573 "level of the dump file. 0 (the default) disables gzip " \
574 "compression. Otherwise the level must be between 1 and 9.") \
575 range(0, 9) \
576 \
577 product(ccstr, NativeMemoryTracking, DEBUG_ONLY("summary") NOT_DEBUG("off"), \
578 "Native memory tracking options") \
579 \
580 product(bool, PrintNMTStatistics, false, DIAGNOSTIC, \
581 "Print native memory tracking summary data if it is on") \
582 \
583 product(bool, LogCompilation, false, DIAGNOSTIC, \
584 "Log compilation activity in detail to LogFile") \
585 \
586 product(bool, PrintCompilation, false, \
587 "Print compilations") \
588 \
589 product(intx, RepeatCompilation, 0, DIAGNOSTIC, \
590 "Repeat compilation without installing code (number of times)") \
591 range(0, max_jint) \
592 \
593 product(bool, PrintExtendedThreadInfo, false, \
594 "Print more information in thread dump") \
595 \
596 product(intx, ScavengeRootsInCode, 2, DIAGNOSTIC, \
597 "0: do not allow scavengable oops in the code cache; " \
598 "1: allow scavenging from the code cache; " \
599 "2: emit as many constants as the compiler can see") \
600 range(0, 2) \
601 \
602 product(bool, AlwaysRestoreFPU, false, \
603 "Restore the FPU control word after every JNI call (expensive)") \
604 \
605 product(bool, PrintCompilation2, false, DIAGNOSTIC, \
606 "Print additional statistics per compilation") \
607 \
608 product(bool, PrintAdapterHandlers, false, DIAGNOSTIC, \
609 "Print code generated for i2c/c2i adapters") \
610 \
611 product(bool, VerifyAdapterCalls, trueInDebug, DIAGNOSTIC, \
612 "Verify that i2c/c2i adapters are called properly") \
613 \
614 develop(bool, VerifyAdapterSharing, false, \
615 "Verify that the code for shared adapters is the equivalent") \
616 \
617 product(bool, PrintAssembly, false, DIAGNOSTIC, \
618 "Print assembly code (using external disassembler.so)") \
619 \
620 product(ccstr, PrintAssemblyOptions, nullptr, DIAGNOSTIC, \
621 "Print options string passed to disassembler.so") \
622 \
623 develop(bool, PrintNMethodStatistics, false, \
624 "Print a summary statistic for the generated nmethods") \
625 \
626 product(bool, PrintNMethods, false, DIAGNOSTIC, \
627 "Print assembly code for nmethods when generated") \
628 \
629 product(bool, PrintNativeNMethods, false, DIAGNOSTIC, \
630 "Print assembly code for native nmethods when generated") \
631 \
632 develop(bool, PrintDebugInfo, false, \
633 "Print debug information for all nmethods when generated") \
634 \
635 develop(bool, PrintRelocations, false, \
636 "Print relocation information for all nmethods when generated") \
637 \
638 develop(bool, PrintDependencies, false, \
639 "Print dependency information for all nmethods when generated") \
640 \
641 develop(bool, PrintExceptionHandlers, false, \
642 "Print exception handler tables for all nmethods when generated") \
643 \
644 develop(bool, StressCompiledExceptionHandlers, false, \
645 "Exercise compiled exception handlers") \
646 \
647 develop(bool, InterceptOSException, false, \
648 "Start debugger when an implicit OS (e.g. null pointer) " \
649 "exception happens") \
650 \
651 product(bool, PrintCodeCache, false, \
652 "Print the code cache memory usage when exiting") \
653 \
654 develop(bool, PrintCodeCache2, false, \
655 "Print detailed usage information on the code cache when exiting")\
656 \
657 product(bool, PrintCodeCacheOnCompilation, false, \
658 "Print the code cache memory usage each time a method is " \
659 "compiled") \
660 \
661 product(bool, PrintCodeHeapAnalytics, false, DIAGNOSTIC, \
662 "Print code heap usage statistics on exit and on full condition") \
663 \
664 product(bool, PrintStubCode, false, DIAGNOSTIC, \
665 "Print generated stub code") \
666 \
667 product(bool, StackTraceInThrowable, true, \
668 "Collect backtrace in throwable when exception happens") \
669 \
670 product(bool, OmitStackTraceInFastThrow, true, \
671 "Omit backtraces for some 'hot' exceptions in optimized code") \
672 \
673 product(bool, ShowCodeDetailsInExceptionMessages, true, MANAGEABLE, \
674 "Show exception messages from RuntimeExceptions that contain " \
675 "snippets of the failing code. Disable this to improve privacy.") \
676 \
677 product(bool, PrintWarnings, true, \
678 "Print JVM warnings to output stream") \
679 \
680 product(bool, RegisterFinalizersAtInit, true, \
681 "(Deprecated) Register finalizable objects at end of " \
682 "Object.<init> or after allocation") \
683 \
684 develop(bool, RegisterReferences, true, \
685 "Tell whether the VM should register soft/weak/final/phantom " \
686 "references") \
687 \
688 develop(bool, PrintCodeCacheExtension, false, \
689 "Print extension of code cache") \
690 \
691 develop(bool, UsePrivilegedStack, true, \
692 "Enable the security JVM functions") \
693 \
694 product(bool, ClassUnloading, true, \
695 "Do unloading of classes") \
696 \
697 product(bool, ClassUnloadingWithConcurrentMark, true, \
698 "Do unloading of classes with a concurrent marking cycle") \
699 \
700 develop(bool, PrintSystemDictionaryAtExit, false, \
701 "Print the system dictionary at exit") \
702 \
703 develop(bool, PrintClassLoaderDataGraphAtExit, false, \
704 "Print the class loader data graph at exit") \
705 \
706 product(bool, AllowParallelDefineClass, false, \
707 "Allow parallel defineClass requests for class loaders " \
708 "registering as parallel capable") \
709 \
710 product_pd(bool, DontYieldALot, \
711 "Throw away obvious excess yield calls") \
712 \
713 product(bool, DisablePrimordialThreadGuardPages, false, EXPERIMENTAL, \
714 "Disable the use of stack guard pages if the JVM is loaded " \
715 "on the primordial process thread") \
716 \
717 product(bool, DoJVMTIVirtualThreadTransitions, true, EXPERIMENTAL, \
718 "Do JVMTI virtual thread mount/unmount transitions " \
719 "(disabling this flag implies no JVMTI events are posted)") \
720 \
721 /* notice: the max range value here is max_jint, not max_intx */ \
722 /* because of overflow issue */ \
723 product(intx, AsyncDeflationInterval, 250, DIAGNOSTIC, \
724 "Async deflate idle monitors every so many milliseconds when " \
725 "MonitorUsedDeflationThreshold is exceeded (0 is off).") \
726 range(0, max_jint) \
727 \
728 /* notice: the max range value here is max_jint, not max_intx */ \
729 /* because of overflow issue */ \
730 product(intx, GuaranteedAsyncDeflationInterval, 60000, DIAGNOSTIC, \
731 "Async deflate idle monitors every so many milliseconds even " \
732 "when MonitorUsedDeflationThreshold is NOT exceeded (0 is off).") \
733 range(0, max_jint) \
734 \
735 product(size_t, AvgMonitorsPerThreadEstimate, 1024, DIAGNOSTIC, \
736 "Used to estimate a variable ceiling based on number of threads " \
737 "for use with MonitorUsedDeflationThreshold (0 is off).") \
738 range(0, max_uintx) \
739 \
740 /* notice: the max range value here is max_jint, not max_intx */ \
741 /* because of overflow issue */ \
742 product(intx, MonitorDeflationMax, 1000000, DIAGNOSTIC, \
743 "The maximum number of monitors to deflate, unlink and delete " \
744 "at one time (minimum is 1024).") \
745 range(1024, max_jint) \
746 \
747 product(intx, MonitorUnlinkBatch, 500, DIAGNOSTIC, \
748 "The maximum number of monitors to unlink in one batch. ") \
749 range(1, max_jint) \
750 \
751 product(int, MonitorUsedDeflationThreshold, 90, DIAGNOSTIC, \
752 "Percentage of used monitors before triggering deflation (0 is " \
753 "off). The check is performed on GuaranteedSafepointInterval, " \
754 "AsyncDeflationInterval or GuaranteedAsyncDeflationInterval, " \
755 "whichever is lower.") \
756 range(0, 100) \
757 \
758 product(uintx, NoAsyncDeflationProgressMax, 3, DIAGNOSTIC, \
759 "Max number of no progress async deflation attempts to tolerate " \
760 "before adjusting the in_use_list_ceiling up (0 is off).") \
761 range(0, max_uintx) \
762 \
763 product(intx, hashCode, 5, EXPERIMENTAL, \
764 "(Unstable) select hashCode generation algorithm") \
765 \
766 product(bool, ReduceSignalUsage, false, \
767 "Reduce the use of OS signals in Java and/or the VM") \
768 \
769 develop(bool, LoadLineNumberTables, true, \
770 "Tell whether the class file parser loads line number tables") \
771 \
772 develop(bool, LoadLocalVariableTables, true, \
773 "Tell whether the class file parser loads local variable tables") \
774 \
775 develop(bool, LoadLocalVariableTypeTables, true, \
776 "Tell whether the class file parser loads local variable type" \
777 "tables") \
778 \
779 product(bool, AllowUserSignalHandlers, false, \
780 "Application will install primary signal handlers for the JVM " \
781 "(Unix only)") \
782 \
783 product(bool, UseSignalChaining, true, \
784 "Use signal-chaining to invoke signal handlers installed " \
785 "by the application (Unix only)") \
786 \
787 product(bool, RestoreMXCSROnJNICalls, false, \
788 "Restore MXCSR when returning from JNI calls") \
789 \
790 product(bool, CheckJNICalls, false, \
791 "Verify all arguments to JNI calls") \
792 \
793 product(bool, UseFastJNIAccessors, true, \
794 "Use optimized versions of Get<Primitive>Field") \
795 \
796 product(intx, MaxJNILocalCapacity, 65536, \
797 "Maximum allowable local JNI handle capacity to " \
798 "EnsureLocalCapacity() and PushLocalFrame(), " \
799 "where <= 0 is unlimited, default: 65536") \
800 range(min_intx, max_intx) \
801 \
802 product(bool, EagerXrunInit, false, \
803 "Eagerly initialize -Xrun libraries; allows startup profiling, " \
804 "but not all -Xrun libraries may support the state of the VM " \
805 "at this time") \
806 \
807 product(bool, PreserveAllAnnotations, false, \
808 "Preserve RuntimeInvisibleAnnotations as well " \
809 "as RuntimeVisibleAnnotations") \
810 \
811 develop(uintx, PreallocatedOutOfMemoryErrorCount, 4, \
812 "Number of OutOfMemoryErrors preallocated with backtrace") \
813 \
814 product(bool, UseXMMForArrayCopy, false, \
815 "Use SSE2 MOVQ instruction for Arraycopy") \
816 \
817 develop(bool, PrintFieldLayout, false, \
818 "Print field layout for each class") \
819 \
820 /* Need to limit the extent of the padding to reasonable size. */\
821 /* 8K is well beyond the reasonable HW cache line size, even with */\
822 /* aggressive prefetching, while still leaving the room for segregating */\
823 /* among the distinct pages. */\
824 product(int, ContendedPaddingWidth, 128, \
825 "How many bytes to pad the fields/classes marked @Contended with")\
826 range(0, 8192) \
827 constraint(ContendedPaddingWidthConstraintFunc,AfterErgo) \
828 \
829 product(bool, EnableContended, true, \
830 "Enable @Contended annotation support") \
831 \
832 product(bool, RestrictContended, true, \
833 "Restrict @Contended to trusted classes") \
834 \
835 product(int, DiagnoseSyncOnValueBasedClasses, 0, DIAGNOSTIC, \
836 "Detect and take action upon identifying synchronization on " \
837 "value based classes. Modes: " \
838 "0: off; " \
839 "1: exit with fatal error; " \
840 "2: log message to stdout. Output file can be specified with " \
841 " -Xlog:valuebasedclasses. If JFR is running it will " \
842 " also generate JFR events.") \
843 range(0, 2) \
844 \
845 product(bool, ExitOnOutOfMemoryError, false, \
846 "JVM exits on the first occurrence of an out-of-memory error " \
847 "thrown from JVM") \
848 \
849 product(bool, CrashOnOutOfMemoryError, false, \
850 "JVM aborts, producing an error log and core/mini dump, on the " \
851 "first occurrence of an out-of-memory error thrown from JVM") \
852 \
853 product(intx, UserThreadWaitAttemptsAtExit, 30, \
854 "The number of times to wait for user threads to stop executing " \
855 "native code during JVM exit. Each wait lasts 10 milliseconds. " \
856 "The maximum number of waits is 1000, to wait at most 10 " \
857 "seconds.") \
858 range(0, 1000) \
859 \
860 /* tracing */ \
861 \
862 develop(bool, StressRewriter, false, \
863 "Stress linktime bytecode rewriting") \
864 \
865 product(ccstr, TraceJVMTI, nullptr, \
866 "Trace flags for JVMTI functions and events") \
867 \
868 product(bool, StressLdcRewrite, false, DIAGNOSTIC, \
869 "Force ldc -> ldc_w rewrite during RedefineClasses. " \
870 "This option can change an EMCP method into an obsolete method " \
871 "and can affect tests that expect specific methods to be EMCP. " \
872 "This option should be used with caution.") \
873 \
874 product(bool, AllowRedefinitionToAddDeleteMethods, false, \
875 "(Deprecated) Allow redefinition to add and delete private " \
876 "static or final methods for compatibility with old releases") \
877 \
878 develop(bool, TraceBytecodes, false, \
879 "Trace bytecode execution") \
880 \
881 develop(bool, TraceInvocationCounterOverflow, false, \
882 "Trace method invocation counter overflow") \
883 \
884 develop(bool, VerifyDependencies, trueInDebug, \
885 "Exercise and verify the compilation dependency mechanism") \
886 \
887 develop(bool, TraceNewOopMapGeneration, false, \
888 "Trace OopMapGeneration") \
889 \
890 develop(bool, TraceNewOopMapGenerationDetailed, false, \
891 "Trace OopMapGeneration: print detailed cell states") \
892 \
893 develop(bool, TimeOopMap, false, \
894 "Time calls to GenerateOopMap::compute_map() in sum") \
895 \
896 develop(bool, TimeOopMap2, false, \
897 "Time calls to GenerateOopMap::compute_map() individually") \
898 \
899 develop(bool, TraceOopMapRewrites, false, \
900 "Trace rewriting of methods during oop map generation") \
901 \
902 develop(bool, TraceFinalizerRegistration, false, \
903 "Trace registration of final references") \
904 \
905 product(bool, IgnoreEmptyClassPaths, false, \
906 "Ignore empty path elements in -classpath") \
907 \
908 product(bool, PrintHeapAtSIGBREAK, true, \
909 "Print heap layout in response to SIGBREAK") \
910 \
911 product(bool, PrintClassHistogram, false, MANAGEABLE, \
912 "Print a histogram of class instances") \
913 \
914 product(double, ObjectCountCutOffPercent, 0.5, EXPERIMENTAL, \
915 "The percentage of the used heap that the instances of a class " \
916 "must occupy for the class to generate a trace event") \
917 range(0.0, 100.0) \
918 \
919 /* JVMTI heap profiling */ \
920 \
921 product(bool, VerifyBeforeIteration, false, DIAGNOSTIC, \
922 "Verify memory system before JVMTI iteration") \
923 \
924 /* compiler */ \
925 \
926 /* notice: the max range value here is max_jint, not max_intx */ \
927 /* because of overflow issue */ \
928 product(intx, CICompilerCount, CI_COMPILER_COUNT, \
929 "Number of compiler threads to run") \
930 range(0, max_jint) \
931 constraint(CICompilerCountConstraintFunc, AfterErgo) \
932 \
933 product(bool, UseDynamicNumberOfCompilerThreads, true, \
934 "Dynamically choose the number of parallel compiler threads") \
935 \
936 product(bool, ReduceNumberOfCompilerThreads, true, DIAGNOSTIC, \
937 "Reduce the number of parallel compiler threads when they " \
938 "are not used") \
939 \
940 product(bool, TraceCompilerThreads, false, DIAGNOSTIC, \
941 "Trace creation and removal of compiler threads") \
942 \
943 product(ccstr, LogClassLoadingCauseFor, nullptr, \
944 "Apply -Xlog:class+load+cause* to classes whose fully " \
945 "qualified name contains this string (\"*\" matches " \
946 "any class).") \
947 \
948 develop(bool, InjectCompilerCreationFailure, false, \
949 "Inject thread creation failures for " \
950 "UseDynamicNumberOfCompilerThreads") \
951 \
952 develop(bool, GenerateSynchronizationCode, true, \
953 "generate locking/unlocking code for synchronized methods and " \
954 "monitors") \
955 \
956 product_pd(bool, ImplicitNullChecks, DIAGNOSTIC, \
957 "Generate code for implicit null checks") \
958 \
959 product_pd(bool, TrapBasedNullChecks, \
960 "Generate code for null checks that uses a cmp and trap " \
961 "instruction raising SIGTRAP. This is only used if an access to" \
962 "null (+offset) will not raise a SIGSEGV, i.e.," \
963 "ImplicitNullChecks don't work (PPC64).") \
964 \
965 product(bool, EnableThreadSMRStatistics, trueInDebug, DIAGNOSTIC, \
966 "Enable Thread SMR Statistics") \
967 \
968 product(bool, UseNotificationThread, true, \
969 "Use Notification Thread") \
970 \
971 product(bool, Inline, true, \
972 "Enable inlining") \
973 \
974 product(bool, ClipInlining, true, \
975 "Clip inlining if aggregate method exceeds DesiredMethodLimit") \
976 \
977 develop(bool, UseCHA, true, \
978 "Enable CHA") \
979 \
980 product(bool, UseVtableBasedCHA, true, DIAGNOSTIC, \
981 "Use vtable information during CHA") \
982 \
983 product(bool, UseTypeProfile, true, \
984 "Check interpreter profile for historically monomorphic calls") \
985 \
986 product(bool, PrintInlining, false, DIAGNOSTIC, \
987 "Print inlining optimizations") \
988 \
989 product(bool, UsePopCountInstruction, false, \
990 "Use population count instruction") \
991 \
992 develop(bool, TraceMethodReplacement, false, \
993 "Print when methods are replaced do to recompilation") \
994 \
995 product(bool, PrintMethodFlushingStatistics, false, DIAGNOSTIC, \
996 "print statistics about method flushing") \
997 \
998 product(intx, MinPassesBeforeFlush, 10, DIAGNOSTIC, \
999 "Minimum number of sweeper passes before an nmethod " \
1000 "can be flushed") \
1001 range(0, max_intx) \
1002 \
1003 develop(bool, StressCodeBuffers, false, \
1004 "Exercise code buffer expansion and other rare state changes") \
1005 \
1006 product(bool, DebugNonSafepoints, trueInDebug, DIAGNOSTIC, \
1007 "Generate extra debugging information for non-safepoints in " \
1008 "nmethods") \
1009 \
1010 product(bool, PrintVMOptions, false, \
1011 "Print flags that appeared on the command line") \
1012 \
1013 product(bool, IgnoreUnrecognizedVMOptions, false, \
1014 "Ignore unrecognized VM options") \
1015 \
1016 product(bool, PrintCommandLineFlags, false, \
1017 "Print flags specified on command line or set by ergonomics") \
1018 \
1019 product(bool, PrintFlagsInitial, false, \
1020 "Print all VM flags before argument processing and exit VM") \
1021 \
1022 product(bool, PrintFlagsFinal, false, \
1023 "Print all VM flags after argument and ergonomic processing") \
1024 \
1025 develop(bool, PrintFlagsWithComments, false, \
1026 "Print all VM flags with default values and descriptions and " \
1027 "exit") \
1028 \
1029 product(bool, PrintFlagsRanges, false, \
1030 "Print VM flags and their ranges") \
1031 \
1032 product(bool, SerializeVMOutput, true, DIAGNOSTIC, \
1033 "Use a mutex to serialize output to tty and LogFile") \
1034 \
1035 product(bool, DisplayVMOutput, true, DIAGNOSTIC, \
1036 "Display all VM output on the tty, independently of LogVMOutput") \
1037 \
1038 product(bool, LogVMOutput, false, DIAGNOSTIC, \
1039 "Save VM output to LogFile") \
1040 \
1041 product(ccstr, LogFile, nullptr, DIAGNOSTIC, \
1042 "If LogVMOutput or LogCompilation is on, save VM output to " \
1043 "this file [default: ./hotspot_pid%p.log] (%p replaced with pid)")\
1044 \
1045 product(ccstr, ErrorFile, nullptr, \
1046 "If an error occurs, save the error data to this file " \
1047 "[default: ./hs_err_pid%p.log] (%p replaced with pid)") \
1048 \
1049 product(bool, ExtensiveErrorReports, \
1050 PRODUCT_ONLY(false) NOT_PRODUCT(true), \
1051 "Error reports are more extensive.") \
1052 \
1053 product(bool, DisplayVMOutputToStderr, false, \
1054 "If DisplayVMOutput is true, display all VM output to stderr") \
1055 \
1056 product(bool, DisplayVMOutputToStdout, false, \
1057 "If DisplayVMOutput is true, display all VM output to stdout") \
1058 \
1059 product(bool, ErrorFileToStderr, false, \
1060 "If true, error data is printed to stderr instead of a file") \
1061 \
1062 product(bool, ErrorFileToStdout, false, \
1063 "If true, error data is printed to stdout instead of a file") \
1064 \
1065 develop(bool, VerifyHeavyMonitors, false, \
1066 "Checks that no stack locking happens when using " \
1067 "-XX:LockingMode=0 (LM_MONITOR)") \
1068 \
1069 product(bool, PrintStringTableStatistics, false, \
1070 "print statistics about the StringTable and SymbolTable") \
1071 \
1072 product(bool, VerifyStringTableAtExit, false, DIAGNOSTIC, \
1073 "verify StringTable contents at exit") \
1074 \
1075 develop(bool, PrintSymbolTableSizeHistogram, false, \
1076 "print histogram of the symbol table") \
1077 \
1078 product(ccstr, AbortVMOnException, nullptr, DIAGNOSTIC, \
1079 "Call fatal if this exception is thrown. Example: " \
1080 "java -XX:AbortVMOnException=java.lang.NullPointerException Foo") \
1081 \
1082 product(ccstr, AbortVMOnExceptionMessage, nullptr, DIAGNOSTIC, \
1083 "Call fatal if the exception pointed by AbortVMOnException " \
1084 "has this message") \
1085 \
1086 develop(bool, DebugVtables, false, \
1087 "add debugging code to vtable dispatch") \
1088 \
1089 product(bool, RangeCheckElimination, true, \
1090 "Eliminate range checks") \
1091 \
1092 develop_pd(bool, UncommonNullCast, \
1093 "track occurrences of null in casts; adjust compiler tactics") \
1094 \
1095 develop(bool, TypeProfileCasts, true, \
1096 "treat casts like calls for purposes of type profiling") \
1097 \
1098 develop(bool, TraceLivenessGen, false, \
1099 "Trace the generation of liveness analysis information") \
1100 \
1101 develop(bool, TraceLivenessQuery, false, \
1102 "Trace queries of liveness analysis information") \
1103 \
1104 develop(bool, CollectIndexSetStatistics, false, \
1105 "Collect information about IndexSets") \
1106 \
1107 develop(int, FastAllocateSizeLimit, 128*K, \
1108 /* Note: This value is zero mod 1<<13 for a cheap sparc set. */ \
1109 "Inline allocations larger than this in doublewords must go slow")\
1110 \
1111 product_pd(bool, CompactStrings, \
1112 "Enable Strings to use single byte chars in backing store") \
1113 \
1114 product_pd(uint, TypeProfileLevel, \
1115 "=XYZ, with Z: Type profiling of arguments at call; " \
1116 "Y: Type profiling of return value at call; " \
1117 "X: Type profiling of parameters to methods; " \
1118 "X, Y and Z in 0=off ; 1=jsr292 only; 2=all methods") \
1119 constraint(TypeProfileLevelConstraintFunc, AfterErgo) \
1120 \
1121 product(int, TypeProfileArgsLimit, 2, \
1122 "max number of call arguments to consider for type profiling") \
1123 range(0, 16) \
1124 \
1125 product(int, TypeProfileParmsLimit, 2, \
1126 "max number of incoming parameters to consider for type profiling"\
1127 ", -1 for all") \
1128 range(-1, 64) \
1129 \
1130 /* statistics */ \
1131 develop(bool, CountCompiledCalls, false, \
1132 "Count method invocations") \
1133 \
1134 develop(bool, ICMissHistogram, false, \
1135 "Produce histogram of IC misses") \
1136 \
1137 /* interpreter */ \
1138 product_pd(bool, RewriteBytecodes, \
1139 "Allow rewriting of bytecodes (bytecodes are not immutable)") \
1140 \
1141 product_pd(bool, RewriteFrequentPairs, \
1142 "Rewrite frequently used bytecode pairs into a single bytecode") \
1143 \
1144 product(bool, PrintInterpreter, false, DIAGNOSTIC, \
1145 "Print the generated interpreter code") \
1146 \
1147 product(bool, UseInterpreter, true, \
1148 "Use interpreter for non-compiled methods") \
1149 \
1150 develop(bool, UseFastSignatureHandlers, true, \
1151 "Use fast signature handlers for native calls") \
1152 \
1153 product(bool, UseLoopCounter, true, \
1154 "Increment invocation counter on backward branch") \
1155 \
1156 product_pd(bool, UseOnStackReplacement, \
1157 "Use on stack replacement, calls runtime if invoc. counter " \
1158 "overflows in loop") \
1159 \
1160 develop(bool, TraceOnStackReplacement, false, \
1161 "Trace on stack replacement") \
1162 \
1163 product_pd(bool, PreferInterpreterNativeStubs, \
1164 "Use always interpreter stubs for native methods invoked via " \
1165 "interpreter") \
1166 \
1167 develop(bool, CountBytecodes, false, \
1168 "Count number of bytecodes executed") \
1169 \
1170 develop(bool, PrintBytecodeHistogram, false, \
1171 "Print histogram of the executed bytecodes") \
1172 \
1173 develop(bool, PrintBytecodePairHistogram, false, \
1174 "Print histogram of the executed bytecode pairs") \
1175 \
1176 product(bool, PrintSignatureHandlers, false, DIAGNOSTIC, \
1177 "Print code generated for native method signature handlers") \
1178 \
1179 develop(bool, VerifyOops, false, \
1180 "Do plausibility checks for oops") \
1181 \
1182 develop(bool, CheckUnhandledOops, false, \
1183 "Check for unhandled oops in VM code") \
1184 \
1185 develop(bool, VerifyJNIFields, trueInDebug, \
1186 "Verify jfieldIDs for instance fields") \
1187 \
1188 develop(bool, VerifyFPU, false, \
1189 "Verify FPU state (check for NaN's, etc.)") \
1190 \
1191 develop(bool, VerifyActivationFrameSize, false, \
1192 "Verify that activation frame didn't become smaller than its " \
1193 "minimal size") \
1194 \
1195 develop(bool, TraceFrequencyInlining, false, \
1196 "Trace frequency based inlining") \
1197 \
1198 develop_pd(bool, InlineIntrinsics, \
1199 "Use intrinsics in Interpreter that can be statically resolved") \
1200 \
1201 product_pd(bool, ProfileInterpreter, \
1202 "Profile at the bytecode level during interpretation") \
1203 \
1204 develop_pd(bool, ProfileTraps, \
1205 "Profile deoptimization traps at the bytecode level") \
1206 \
1207 product(intx, ProfileMaturityPercentage, 20, \
1208 "number of method invocations/branches (expressed as % of " \
1209 "CompileThreshold) before using the method's profile") \
1210 range(0, 100) \
1211 \
1212 product(bool, PrintMethodData, false, DIAGNOSTIC, \
1213 "Print the results of +ProfileInterpreter at end of run") \
1214 \
1215 develop(bool, VerifyDataPointer, trueInDebug, \
1216 "Verify the method data pointer during interpreter profiling") \
1217 \
1218 develop(bool, CrashGCForDumpingJavaThread, false, \
1219 "Manually make GC thread crash then dump java stack trace; " \
1220 "Test only") \
1221 \
1222 /* compilation */ \
1223 product(bool, UseCompiler, true, \
1224 "Use Just-In-Time compilation") \
1225 \
1226 develop(intx, CounterHalfLifeTime, 30, \
1227 "Half-life time of invocation counters (in seconds)") \
1228 \
1229 product(bool, AlwaysCompileLoopMethods, false, \
1230 "When using recompilation, never interpret methods " \
1231 "containing loops") \
1232 \
1233 product(int, AllocatePrefetchStyle, 1, \
1234 "0 = no prefetch, " \
1235 "1 = generate prefetch instructions for each allocation, " \
1236 "2 = use TLAB watermark to gate allocation prefetch, " \
1237 "3 = generate one prefetch instruction per cache line") \
1238 range(0, 3) \
1239 \
1240 product(int, AllocatePrefetchDistance, -1, \
1241 "Distance to prefetch ahead of allocation pointer. " \
1242 "-1: use system-specific value (automatically determined") \
1243 range(-1, 512) \
1244 \
1245 product(int, AllocatePrefetchLines, 3, \
1246 "Number of lines to prefetch ahead of array allocation pointer") \
1247 range(1, 64) \
1248 \
1249 product(int, AllocateInstancePrefetchLines, 1, \
1250 "Number of lines to prefetch ahead of instance allocation " \
1251 "pointer") \
1252 range(1, 64) \
1253 \
1254 product(int, AllocatePrefetchStepSize, 16, \
1255 "Step size in bytes of sequential prefetch instructions") \
1256 range(1, 512) \
1257 constraint(AllocatePrefetchStepSizeConstraintFunc,AfterMemoryInit)\
1258 \
1259 product(intx, AllocatePrefetchInstr, 0, \
1260 "Select instruction to prefetch ahead of allocation pointer") \
1261 constraint(AllocatePrefetchInstrConstraintFunc, AfterMemoryInit) \
1262 \
1263 /* deoptimization */ \
1264 product(bool, TraceDeoptimization, false, DIAGNOSTIC, \
1265 "Trace deoptimization") \
1266 \
1267 develop(bool, PrintDeoptimizationDetails, false, \
1268 "Print more information about deoptimization") \
1269 \
1270 develop(bool, DebugDeoptimization, false, \
1271 "Tracing various information while debugging deoptimization") \
1272 \
1273 product(double, SelfDestructTimer, 0.0, \
1274 "Will cause VM to terminate after a given time " \
1275 "(in fractional minutes) " \
1276 "(0.0 means off)") \
1277 range(0.0, (double)max_intx) \
1278 \
1279 product(int, MaxJavaStackTraceDepth, 1024, \
1280 "The maximum number of lines in the stack trace for Java " \
1281 "exceptions (0 means all)") \
1282 range(0, max_jint/2) \
1283 \
1284 /* notice: the max range value here is max_jint, not max_intx */ \
1285 /* because of overflow issue */ \
1286 product(intx, GuaranteedSafepointInterval, 1000, DIAGNOSTIC, \
1287 "Guarantee a safepoint (at least) every so many milliseconds " \
1288 "(0 means none)") \
1289 range(0, max_jint) \
1290 \
1291 product(intx, ServiceThreadCleanupInterval, 1000, DIAGNOSTIC, \
1292 "Wake the ServiceThread to do periodic cleanup checks every so " \
1293 "many milliseconds (0 means none)") \
1294 range(0, max_jint) \
1295 \
1296 product(double, SafepointTimeoutDelay, 10000, \
1297 "Delay in milliseconds for option SafepointTimeout; " \
1298 "supports sub-millisecond resolution with fractional values.") \
1299 range(0, max_jlongDouble LP64_ONLY(/MICROUNITS)) \
1300 \
1301 product(bool, UseSystemMemoryBarrier, false, \
1302 "Try to enable system memory barrier if supported by OS") \
1303 \
1304 product(intx, NmethodSweepActivity, 4, \
1305 "Removes cold nmethods from code cache if > 0. Higher values " \
1306 "result in more aggressive sweeping") \
1307 range(0, 2000) \
1308 \
1309 develop(intx, MallocCatchPtr, -1, \
1310 "Hit breakpoint when mallocing/freeing this pointer") \
1311 \
1312 develop(int, StackPrintLimit, 100, \
1313 "number of stack frames to print in VM-level stack dump") \
1314 \
1315 product(int, ErrorLogPrintCodeLimit, 3, DIAGNOSTIC, \
1316 "max number of compiled code units to print in error log") \
1317 range(0, VMError::max_error_log_print_code) \
1318 \
1319 develop(int, MaxElementPrintSize, 256, \
1320 "maximum number of elements to print") \
1321 \
1322 develop(intx, MaxSubklassPrintSize, 4, \
1323 "maximum number of subklasses to print when printing klass") \
1324 \
1325 develop(intx, MaxForceInlineLevel, 100, \
1326 "maximum number of nested calls that are forced for inlining " \
1327 "(using CompileCommand or marked w/ @ForceInline)") \
1328 range(0, max_jint) \
1329 \
1330 develop(intx, MethodHistogramCutoff, 100, \
1331 "The cutoff value for method invocation histogram (+CountCalls)") \
1332 \
1333 develop(intx, DontYieldALotInterval, 10, \
1334 "Interval between which yields will be dropped (milliseconds)") \
1335 \
1336 develop(intx, DeoptimizeALotInterval, 5, \
1337 "Number of exits until DeoptimizeALot kicks in") \
1338 \
1339 develop(intx, ZombieALotInterval, 5, \
1340 "Number of exits until ZombieALot kicks in") \
1341 \
1342 product(ccstr, MallocLimit, nullptr, DIAGNOSTIC, \
1343 "Limit malloc allocation size from VM. Reaching a limit will " \
1344 "trigger an action (see flag). This feature requires " \
1345 "NativeMemoryTracking=summary or NativeMemoryTracking=detail." \
1346 "Usage:" \
1347 "\"-XX:MallocLimit=<size>[:<flag>]\" sets a total limit." \
1348 "\"-XX:MallocLimit=<category>:<size>[:<flag>][,<category>:<size>[:<flag>] ...]\"" \
1349 "sets one or more category-specific limits." \
1350 "<flag> defines the action upon reaching the limit:" \
1351 "\"fatal\": end VM with a fatal error at the allocation site" \
1352 "\"oom\" : will mimic a native OOM" \
1353 "If <flag> is omitted, \"fatal\" is the default." \
1354 "Examples:\n" \
1355 "-XX:MallocLimit=2g" \
1356 "-XX:MallocLimit=2g:oom" \
1357 "-XX:MallocLimit=compiler:200m:oom,code:100m") \
1358 \
1359 product(intx, TypeProfileWidth, 2, \
1360 "Number of receiver types to record in call/cast profile") \
1361 range(0, 8) \
1362 \
1363 develop(intx, BciProfileWidth, 2, \
1364 "Number of return bci's to record in ret profile") \
1365 \
1366 product(intx, PerMethodRecompilationCutoff, 400, \
1367 "After recompiling N times, stay in the interpreter (-1=>'Inf')") \
1368 range(-1, max_intx) \
1369 \
1370 product(intx, PerBytecodeRecompilationCutoff, 200, \
1371 "Per-BCI limit on repeated recompilation (-1=>'Inf')") \
1372 range(-1, max_intx) \
1373 \
1374 product(intx, PerMethodTrapLimit, 100, \
1375 "Limit on traps (of one kind) in a method (includes inlines)") \
1376 range(0, max_jint) \
1377 \
1378 product(intx, PerMethodSpecTrapLimit, 5000, EXPERIMENTAL, \
1379 "Limit on speculative traps (of one kind) in a method " \
1380 "(includes inlines)") \
1381 range(0, max_jint) \
1382 \
1383 product(intx, PerBytecodeTrapLimit, 4, \
1384 "Limit on traps (of one kind) at a particular BCI") \
1385 range(0, max_jint) \
1386 \
1387 product(int, SpecTrapLimitExtraEntries, 3, EXPERIMENTAL, \
1388 "Extra method data trap entries for speculation") \
1389 \
1390 product(double, InlineFrequencyRatio, 0.25, DIAGNOSTIC, \
1391 "Ratio of call site execution to caller method invocation") \
1392 \
1393 product(double, MinInlineFrequencyRatio, 0.0085, DIAGNOSTIC, \
1394 "Minimum ratio of call site execution to caller method" \
1395 "invocation to be considered for inlining") \
1396 \
1397 develop(intx, InlineThrowCount, 50, \
1398 "Force inlining of interpreted methods that throw this often") \
1399 range(0, max_jint) \
1400 \
1401 develop(intx, InlineThrowMaxSize, 200, \
1402 "Force inlining of throwing methods smaller than this") \
1403 range(0, max_jint) \
1404 \
1405 product(size_t, MetaspaceSize, NOT_LP64(16 * M) LP64_ONLY(21 * M), \
1406 "Initial threshold (in bytes) at which a garbage collection " \
1407 "is done to reduce Metaspace usage") \
1408 constraint(MetaspaceSizeConstraintFunc,AfterErgo) \
1409 \
1410 product(size_t, MaxMetaspaceSize, max_uintx, \
1411 "Maximum size of Metaspaces (in bytes)") \
1412 constraint(MaxMetaspaceSizeConstraintFunc,AfterErgo) \
1413 \
1414 product(size_t, CompressedClassSpaceSize, 1*G, \
1415 "Maximum size of class area in Metaspace when compressed " \
1416 "class pointers are used") \
1417 range(1*M, 3*G) \
1418 \
1419 develop(size_t, CompressedClassSpaceBaseAddress, 0, \
1420 "Force the class space to be allocated at this address or " \
1421 "fails VM initialization (requires -Xshare=off.") \
1422 \
1423 develop(bool, RandomizeClassSpaceLocation, true, \
1424 "Randomize location of class space.") \
1425 \
1426 product(bool, PrintMetaspaceStatisticsAtExit, false, DIAGNOSTIC, \
1427 "Print metaspace statistics upon VM exit.") \
1428 \
1429 develop(bool, MetaspaceGuardAllocations, false, \
1430 "Metapace allocations are guarded.") \
1431 \
1432 product(uintx, MinHeapFreeRatio, 40, MANAGEABLE, \
1433 "The minimum percentage of heap free after GC to avoid expansion."\
1434 " For most GCs this applies to the old generation. In G1 and" \
1435 " ParallelGC it applies to the whole heap.") \
1436 range(0, 100) \
1437 constraint(MinHeapFreeRatioConstraintFunc,AfterErgo) \
1438 \
1439 product(uintx, MaxHeapFreeRatio, 70, MANAGEABLE, \
1440 "The maximum percentage of heap free after GC to avoid shrinking."\
1441 " For most GCs this applies to the old generation. In G1 and" \
1442 " ParallelGC it applies to the whole heap.") \
1443 range(0, 100) \
1444 constraint(MaxHeapFreeRatioConstraintFunc,AfterErgo) \
1445 \
1446 product(bool, ShrinkHeapInSteps, true, \
1447 "When disabled, informs the GC to shrink the java heap directly" \
1448 " to the target size at the next full GC rather than requiring" \
1449 " smaller steps during multiple full GCs.") \
1450 \
1451 product(intx, SoftRefLRUPolicyMSPerMB, 1000, \
1452 "Number of milliseconds per MB of free space in the heap") \
1453 range(0, max_intx) \
1454 constraint(SoftRefLRUPolicyMSPerMBConstraintFunc,AfterMemoryInit) \
1455 \
1456 product(size_t, MinHeapDeltaBytes, ScaleForWordSize(128*K), \
1457 "The minimum change in heap space due to GC (in bytes)") \
1458 range(0, max_uintx) \
1459 \
1460 product(size_t, MinMetaspaceExpansion, ScaleForWordSize(256*K), \
1461 "The minimum expansion of Metaspace (in bytes)") \
1462 range(0, max_uintx) \
1463 \
1464 product(uint, MaxMetaspaceFreeRatio, 70, \
1465 "The maximum percentage of Metaspace free after GC to avoid " \
1466 "shrinking") \
1467 range(0, 100) \
1468 constraint(MaxMetaspaceFreeRatioConstraintFunc,AfterErgo) \
1469 \
1470 product(uint, MinMetaspaceFreeRatio, 40, \
1471 "The minimum percentage of Metaspace free after GC to avoid " \
1472 "expansion") \
1473 range(0, 99) \
1474 constraint(MinMetaspaceFreeRatioConstraintFunc,AfterErgo) \
1475 \
1476 product(size_t, MaxMetaspaceExpansion, ScaleForWordSize(4*M), \
1477 "The maximum expansion of Metaspace without full GC (in bytes)") \
1478 range(0, max_uintx) \
1479 \
1480 /* stack parameters */ \
1481 product_pd(intx, StackYellowPages, \
1482 "Number of yellow zone (recoverable overflows) pages of size " \
1483 "4KB. If pages are bigger yellow zone is aligned up.") \
1484 range(MIN_STACK_YELLOW_PAGES, (DEFAULT_STACK_YELLOW_PAGES+5)) \
1485 \
1486 product_pd(intx, StackRedPages, \
1487 "Number of red zone (unrecoverable overflows) pages of size " \
1488 "4KB. If pages are bigger red zone is aligned up.") \
1489 range(MIN_STACK_RED_PAGES, (DEFAULT_STACK_RED_PAGES+2)) \
1490 \
1491 product_pd(intx, StackReservedPages, \
1492 "Number of reserved zone (reserved to annotated methods) pages" \
1493 " of size 4KB. If pages are bigger reserved zone is aligned up.") \
1494 range(MIN_STACK_RESERVED_PAGES, (DEFAULT_STACK_RESERVED_PAGES+10))\
1495 \
1496 product(bool, RestrictReservedStack, true, \
1497 "Restrict @ReservedStackAccess to trusted classes") \
1498 \
1499 /* greater stack shadow pages can't generate instruction to bang stack */ \
1500 product_pd(intx, StackShadowPages, \
1501 "Number of shadow zone (for overflow checking) pages of size " \
1502 "4KB. If pages are bigger shadow zone is aligned up. " \
1503 "This should exceed the depth of the VM and native call stack.") \
1504 range(MIN_STACK_SHADOW_PAGES, (DEFAULT_STACK_SHADOW_PAGES+30)) \
1505 \
1506 product_pd(intx, ThreadStackSize, \
1507 "Thread Stack Size (in Kbytes)") \
1508 range(0, 1 * M) \
1509 \
1510 product_pd(intx, VMThreadStackSize, \
1511 "Non-Java Thread Stack Size (in Kbytes)") \
1512 range(0, max_intx/(1 * K)) \
1513 \
1514 product_pd(intx, CompilerThreadStackSize, \
1515 "Compiler Thread Stack Size (in Kbytes)") \
1516 range(0, max_intx/(1 * K)) \
1517 \
1518 develop_pd(size_t, JVMInvokeMethodSlack, \
1519 "Stack space (bytes) required for JVM_InvokeMethod to complete") \
1520 \
1521 /* code cache parameters */ \
1522 product_pd(uintx, CodeCacheSegmentSize, EXPERIMENTAL, \
1523 "Code cache segment size (in bytes) - smallest unit of " \
1524 "allocation") \
1525 range(1, 1024) \
1526 constraint(CodeCacheSegmentSizeConstraintFunc, AfterErgo) \
1527 \
1528 product_pd(intx, CodeEntryAlignment, EXPERIMENTAL, \
1529 "Code entry alignment for generated code (in bytes)") \
1530 constraint(CodeEntryAlignmentConstraintFunc, AfterErgo) \
1531 \
1532 product_pd(intx, OptoLoopAlignment, \
1533 "Align inner loops to zero relative to this modulus") \
1534 range(1, 128) \
1535 constraint(OptoLoopAlignmentConstraintFunc, AfterErgo) \
1536 \
1537 product_pd(uintx, InitialCodeCacheSize, \
1538 "Initial code cache size (in bytes)") \
1539 constraint(VMPageSizeConstraintFunc, AtParse) \
1540 \
1541 develop_pd(uintx, CodeCacheMinimumUseSpace, \
1542 "Minimum code cache size (in bytes) required to start VM.") \
1543 range(0, max_uintx) \
1544 \
1545 product(bool, SegmentedCodeCache, false, \
1546 "Use a segmented code cache") \
1547 \
1548 product_pd(uintx, ReservedCodeCacheSize, \
1549 "Reserved code cache size (in bytes) - maximum code cache size") \
1550 constraint(VMPageSizeConstraintFunc, AtParse) \
1551 \
1552 product_pd(uintx, NonProfiledCodeHeapSize, \
1553 "Size of code heap with non-profiled methods (in bytes)") \
1554 range(0, max_uintx) \
1555 \
1556 product_pd(uintx, ProfiledCodeHeapSize, \
1557 "Size of code heap with profiled methods (in bytes)") \
1558 range(0, max_uintx) \
1559 \
1560 product_pd(uintx, NonNMethodCodeHeapSize, \
1561 "Size of code heap with non-nmethods (in bytes)") \
1562 constraint(VMPageSizeConstraintFunc, AtParse) \
1563 \
1564 product_pd(uintx, CodeCacheExpansionSize, \
1565 "Code cache expansion size (in bytes)") \
1566 range(32*K, max_uintx) \
1567 \
1568 product_pd(uintx, CodeCacheMinBlockLength, DIAGNOSTIC, \
1569 "Minimum number of segments in a code cache block") \
1570 range(1, 100) \
1571 \
1572 develop(bool, ExitOnFullCodeCache, false, \
1573 "Exit the VM if we fill the code cache") \
1574 \
1575 product(bool, UseCodeCacheFlushing, true, \
1576 "Remove cold/old nmethods from the code cache") \
1577 \
1578 product(double, SweeperThreshold, 15.0, \
1579 "Threshold when a code cache unloading GC is invoked." \
1580 "Value is percentage of ReservedCodeCacheSize.") \
1581 range(0.0, 100.0) \
1582 \
1583 product(uintx, StartAggressiveSweepingAt, 10, \
1584 "Start aggressive sweeping if X[%] of the code cache is free." \
1585 "Segmented code cache: X[%] of the non-profiled heap." \
1586 "Non-segmented code cache: X[%] of the total code cache") \
1587 range(0, 100) \
1588 \
1589 /* interpreter debugging */ \
1590 develop(intx, BinarySwitchThreshold, 5, \
1591 "Minimal number of lookupswitch entries for rewriting to binary " \
1592 "switch") \
1593 \
1594 develop(intx, StopInterpreterAt, 0, \
1595 "Stop interpreter execution at specified bytecode number") \
1596 \
1597 develop(intx, TraceBytecodesAt, 0, \
1598 "Trace bytecodes starting with specified bytecode number") \
1599 \
1600 develop(intx, TraceBytecodesStopAt, 0, \
1601 "Stop bytecode tracing at the specified bytecode number") \
1602 \
1603 /* Priorities */ \
1604 product_pd(bool, UseThreadPriorities, "Use native thread priorities") \
1605 \
1606 product(int, ThreadPriorityPolicy, 0, \
1607 "0 : Normal. "\
1608 " VM chooses priorities that are appropriate for normal "\
1609 " applications. "\
1610 " On Windows applications are allowed to use higher native "\
1611 " priorities. However, with ThreadPriorityPolicy=0, VM will "\
1612 " not use the highest possible native priority, "\
1613 " THREAD_PRIORITY_TIME_CRITICAL, as it may interfere with "\
1614 " system threads. On Linux thread priorities are ignored "\
1615 " because the OS does not support static priority in "\
1616 " SCHED_OTHER scheduling class which is the only choice for "\
1617 " non-root, non-realtime applications. "\
1618 "1 : Aggressive. "\
1619 " Java thread priorities map over to the entire range of "\
1620 " native thread priorities. Higher Java thread priorities map "\
1621 " to higher native thread priorities. This policy should be "\
1622 " used with care, as sometimes it can cause performance "\
1623 " degradation in the application and/or the entire system. On "\
1624 " Linux/BSD/macOS this policy requires root privilege or an "\
1625 " extended capability.") \
1626 range(0, 1) \
1627 \
1628 product(bool, ThreadPriorityVerbose, false, \
1629 "Print priority changes") \
1630 \
1631 product(int, CompilerThreadPriority, -1, \
1632 "The native priority at which compiler threads should run " \
1633 "(-1 means no change)") \
1634 range(min_jint, max_jint) \
1635 \
1636 product(int, VMThreadPriority, -1, \
1637 "The native priority at which the VM thread should run " \
1638 "(-1 means no change)") \
1639 range(-1, 127) \
1640 \
1641 product(int, JavaPriority1_To_OSPriority, -1, \
1642 "Map Java priorities to OS priorities") \
1643 range(-1, 127) \
1644 \
1645 product(int, JavaPriority2_To_OSPriority, -1, \
1646 "Map Java priorities to OS priorities") \
1647 range(-1, 127) \
1648 \
1649 product(int, JavaPriority3_To_OSPriority, -1, \
1650 "Map Java priorities to OS priorities") \
1651 range(-1, 127) \
1652 \
1653 product(int, JavaPriority4_To_OSPriority, -1, \
1654 "Map Java priorities to OS priorities") \
1655 range(-1, 127) \
1656 \
1657 product(int, JavaPriority5_To_OSPriority, -1, \
1658 "Map Java priorities to OS priorities") \
1659 range(-1, 127) \
1660 \
1661 product(int, JavaPriority6_To_OSPriority, -1, \
1662 "Map Java priorities to OS priorities") \
1663 range(-1, 127) \
1664 \
1665 product(int, JavaPriority7_To_OSPriority, -1, \
1666 "Map Java priorities to OS priorities") \
1667 range(-1, 127) \
1668 \
1669 product(int, JavaPriority8_To_OSPriority, -1, \
1670 "Map Java priorities to OS priorities") \
1671 range(-1, 127) \
1672 \
1673 product(int, JavaPriority9_To_OSPriority, -1, \
1674 "Map Java priorities to OS priorities") \
1675 range(-1, 127) \
1676 \
1677 product(int, JavaPriority10_To_OSPriority,-1, \
1678 "Map Java priorities to OS priorities") \
1679 range(-1, 127) \
1680 \
1681 product(bool, UseCriticalJavaThreadPriority, false, EXPERIMENTAL, \
1682 "Java thread priority 10 maps to critical scheduling priority") \
1683 \
1684 product(bool, UseCriticalCompilerThreadPriority, false, EXPERIMENTAL, \
1685 "Compiler thread(s) run at critical scheduling priority") \
1686 \
1687 develop(intx, NewCodeParameter, 0, \
1688 "Testing Only: Create a dedicated integer parameter before " \
1689 "putback") \
1690 \
1691 /* new oopmap storage allocation */ \
1692 develop(intx, MinOopMapAllocation, 8, \
1693 "Minimum number of OopMap entries in an OopMapSet") \
1694 \
1695 /* recompilation */ \
1696 product_pd(intx, CompileThreshold, \
1697 "number of interpreted method invocations before (re-)compiling") \
1698 constraint(CompileThresholdConstraintFunc, AfterErgo) \
1699 \
1700 product_pd(bool, TieredCompilation, \
1701 "Enable tiered compilation") \
1702 \
1703 /* Properties for Java libraries */ \
1704 \
1705 product(uint64_t, MaxDirectMemorySize, 0, \
1706 "Maximum total size of NIO direct-buffer allocations. " \
1707 "Ignored if not explicitly set.") \
1708 range(0, max_jlong) \
1709 \
1710 /* Flags used for temporary code during development */ \
1711 \
1712 product(bool, UseNewCode, false, DIAGNOSTIC, \
1713 "Testing Only: Use the new version while testing") \
1714 \
1715 product(bool, UseNewCode2, false, DIAGNOSTIC, \
1716 "Testing Only: Use the new version while testing") \
1717 \
1718 product(bool, UseNewCode3, false, DIAGNOSTIC, \
1719 "Testing Only: Use the new version while testing") \
1720 \
1721 develop(bool, UseDebuggerErgo, false, \
1722 "Debugging Only: Adjust the VM to be more debugger-friendly. " \
1723 "Turns on the other UseDebuggerErgo* flags") \
1724 \
1725 develop(bool, UseDebuggerErgo1, false, \
1726 "Debugging Only: Enable workarounds for debugger induced " \
1727 "os::processor_id() >= os::processor_count() problems") \
1728 \
1729 develop(bool, UseDebuggerErgo2, false, \
1730 "Debugging Only: Limit the number of spawned JVM threads") \
1731 \
1732 develop(bool, EnableJVMTIStackDepthAsserts, true, \
1733 "Enable JVMTI asserts related to stack depth checks") \
1734 \
1735 /* flags for performance data collection */ \
1736 \
1737 product(bool, UsePerfData, true, \
1738 "Flag to disable jvmstat instrumentation for performance testing "\
1739 "and problem isolation purposes") \
1740 \
1741 product(bool, PerfDataSaveToFile, false, \
1742 "Save PerfData memory to hsperfdata_<pid> file on exit") \
1743 \
1744 product(ccstr, PerfDataSaveFile, nullptr, \
1745 "Save PerfData memory to the specified absolute pathname. " \
1746 "The string %p in the file name (if present) " \
1747 "will be replaced by pid") \
1748 \
1749 product(int, PerfDataSamplingInterval, 50, \
1750 "Data sampling interval (in milliseconds)") \
1751 range(PeriodicTask::min_interval, max_jint) \
1752 constraint(PerfDataSamplingIntervalFunc, AfterErgo) \
1753 \
1754 product(bool, PerfDisableSharedMem, false, \
1755 "Store performance data in standard memory") \
1756 \
1757 product(int, PerfDataMemorySize, 32*K, \
1758 "Size of performance data memory region. Will be rounded " \
1759 "up to a multiple of the native os page size.") \
1760 range(128, 32*64*K) \
1761 \
1762 product(int, PerfMaxStringConstLength, 1024, \
1763 "Maximum PerfStringConstant string length before truncation") \
1764 range(32, 32*K) \
1765 \
1766 product(bool, PerfAllowAtExitRegistration, false, \
1767 "Allow registration of atexit() methods") \
1768 \
1769 product(bool, PerfBypassFileSystemCheck, false, \
1770 "Bypass Win32 file system criteria checks (Windows Only)") \
1771 \
1772 product(int, UnguardOnExecutionViolation, 0, \
1773 "Unguard page and retry on no-execute fault (Win32 only) " \
1774 "0=off, 1=conservative, 2=aggressive") \
1775 range(0, 2) \
1776 \
1777 /* Serviceability Support */ \
1778 \
1779 product(bool, ManagementServer, false, \
1780 "Create JMX Management Server") \
1781 \
1782 product(bool, DisableAttachMechanism, false, \
1783 "Disable mechanism that allows tools to attach to this VM") \
1784 \
1785 product(bool, StartAttachListener, false, \
1786 "Always start Attach Listener at VM startup") \
1787 \
1788 product(bool, EnableDynamicAgentLoading, true, \
1789 "Allow tools to load agents with the attach mechanism") \
1790 \
1791 product(bool, PrintConcurrentLocks, false, MANAGEABLE, \
1792 "Print java.util.concurrent locks in thread dump") \
1793 \
1794 product(bool, PrintMethodHandleStubs, false, DIAGNOSTIC, \
1795 "Print generated stub code for method handles") \
1796 \
1797 product(bool, VerifyMethodHandles, trueInDebug, DIAGNOSTIC, \
1798 "perform extra checks when constructing method handles") \
1799 \
1800 product(bool, ShowHiddenFrames, false, DIAGNOSTIC, \
1801 "show method handle implementation frames (usually hidden)") \
1802 \
1803 product(bool, ShowCarrierFrames, false, DIAGNOSTIC, \
1804 "show virtual threads' carrier frames in exceptions") \
1805 \
1806 product(bool, TrustFinalNonStaticFields, false, EXPERIMENTAL, \
1807 "trust final non-static declarations for constant folding") \
1808 \
1809 product(bool, FoldStableValues, true, DIAGNOSTIC, \
1810 "Optimize loads from stable fields (marked w/ @Stable)") \
1811 \
1812 product(int, UseBootstrapCallInfo, 1, DIAGNOSTIC, \
1813 "0: when resolving InDy or ConDy, force all BSM arguments to be " \
1814 "resolved before the bootstrap method is called; 1: when a BSM " \
1815 "that may accept a BootstrapCallInfo is detected, use that API " \
1816 "to pass BSM arguments, which allows the BSM to delay their " \
1817 "resolution; 2+: stress test the BCI API by calling more BSMs " \
1818 "via that API, instead of with the eagerly-resolved array.") \
1819 \
1820 product(bool, PauseAtStartup, false, DIAGNOSTIC, \
1821 "Causes the VM to pause at startup time and wait for the pause " \
1822 "file to be removed (default: ./vm.paused.<pid>)") \
1823 \
1824 product(ccstr, PauseAtStartupFile, nullptr, DIAGNOSTIC, \
1825 "The file to create and for whose removal to await when pausing " \
1826 "at startup. (default: ./vm.paused.<pid>)") \
1827 \
1828 product(bool, PauseAtExit, false, DIAGNOSTIC, \
1829 "Pause and wait for keypress on exit if a debugger is attached") \
1830 \
1831 product(bool, DTraceMethodProbes, false, \
1832 "Enable dtrace tool probes for method-entry and method-exit") \
1833 \
1834 product(bool, DTraceAllocProbes, false, \
1835 "Enable dtrace tool probes for object allocation") \
1836 \
1837 product(bool, DTraceMonitorProbes, false, \
1838 "Enable dtrace tool probes for monitor events") \
1839 \
1840 product(bool, RelaxAccessControlCheck, false, \
1841 "Relax the access control checks in the verifier") \
1842 \
1843 product(uintx, StringTableSize, defaultStringTableSize, \
1844 "Number of buckets in the interned String table " \
1845 "(will be rounded to nearest higher power of 2)") \
1846 range(minimumStringTableSize, 16777216ul /* 2^24 */) \
1847 \
1848 product(uintx, SymbolTableSize, defaultSymbolTableSize, EXPERIMENTAL, \
1849 "Number of buckets in the JVM internal Symbol table") \
1850 range(minimumSymbolTableSize, 16777216ul /* 2^24 */) \
1851 \
1852 product(bool, UseStringDeduplication, false, \
1853 "Use string deduplication") \
1854 \
1855 product(uint, StringDeduplicationAgeThreshold, 3, \
1856 "A string must reach this age (or be promoted to an old region) " \
1857 "to be considered for deduplication") \
1858 range(1, markWord::max_age) \
1859 \
1860 product(size_t, StringDeduplicationInitialTableSize, 500, EXPERIMENTAL, \
1861 "Approximate initial number of buckets in the table") \
1862 range(1, 1 * G) \
1863 \
1864 product(double, StringDeduplicationGrowTableLoad, 14.0, EXPERIMENTAL, \
1865 "Entries per bucket above which the table should be expanded") \
1866 range(0.1, 1000.0) \
1867 \
1868 product(double, StringDeduplicationShrinkTableLoad, 1.0, EXPERIMENTAL, \
1869 "Entries per bucket below which the table should be shrunk") \
1870 range(0.01, 100.0) \
1871 \
1872 product(double, StringDeduplicationTargetTableLoad, 7.0, EXPERIMENTAL, \
1873 "Desired entries per bucket when resizing the table") \
1874 range(0.01, 1000.0) \
1875 \
1876 product(size_t, StringDeduplicationCleanupDeadMinimum, 100, EXPERIMENTAL, \
1877 "Minimum number of dead table entries for cleaning the table") \
1878 \
1879 product(int, StringDeduplicationCleanupDeadPercent, 5, EXPERIMENTAL, \
1880 "Minimum percentage of dead table entries for cleaning the table") \
1881 range(1, 100) \
1882 \
1883 product(bool, StringDeduplicationResizeALot, false, DIAGNOSTIC, \
1884 "Force more frequent table resizing") \
1885 \
1886 product(uint64_t, StringDeduplicationHashSeed, 0, DIAGNOSTIC, \
1887 "Seed for the table hashing function; 0 requests computed seed") \
1888 \
1889 product(bool, WhiteBoxAPI, false, DIAGNOSTIC, \
1890 "Enable internal testing APIs") \
1891 \
1892 product(bool, AlwaysAtomicAccesses, false, EXPERIMENTAL, \
1893 "Accesses to all variables should always be atomic") \
1894 \
1895 product(bool, UseUnalignedAccesses, false, DIAGNOSTIC, \
1896 "Use unaligned memory accesses in Unsafe") \
1897 \
1898 product_pd(bool, PreserveFramePointer, \
1899 "Use the FP register for holding the frame pointer " \
1900 "and not as a general purpose register.") \
1901 \
1902 product(size_t, AsyncLogBufferSize, 2*M, \
1903 "Memory budget (in bytes) for the buffer of Asynchronous " \
1904 "Logging (-Xlog:async).") \
1905 range(100*K, 50*M) \
1906 \
1907 product(bool, CheckIntrinsics, true, DIAGNOSTIC, \
1908 "When a class C is loaded, check that " \
1909 "(1) all intrinsics defined by the VM for class C are present "\
1910 "in the loaded class file and are marked with the " \
1911 "@IntrinsicCandidate annotation, that " \
1912 "(2) there is an intrinsic registered for all loaded methods " \
1913 "that are annotated with the @IntrinsicCandidate annotation, " \
1914 "and that " \
1915 "(3) no orphan methods exist for class C (i.e., methods for " \
1916 "which the VM declares an intrinsic but that are not declared "\
1917 "in the loaded class C. " \
1918 "Check (3) is available only in debug builds.") \
1919 \
1920 product_pd(intx, InitArrayShortSize, DIAGNOSTIC, \
1921 "Threshold small size (in bytes) for clearing arrays. " \
1922 "Anything this size or smaller may get converted to discrete " \
1923 "scalar stores.") \
1924 range(0, max_intx) \
1925 constraint(InitArrayShortSizeConstraintFunc, AfterErgo) \
1926 \
1927 product(ccstr, AllocateHeapAt, nullptr, \
1928 "Path to the directory where a temporary file will be created " \
1929 "to use as the backing store for Java Heap.") \
1930 \
1931 product_pd(bool, VMContinuations, EXPERIMENTAL, \
1932 "Enable VM continuations support") \
1933 \
1934 develop(bool, LoomDeoptAfterThaw, false, \
1935 "Deopt stack after thaw") \
1936 \
1937 develop(bool, LoomVerifyAfterThaw, false, \
1938 "Verify stack after thaw") \
1939 \
1940 develop(bool, VerifyContinuations, false, \
1941 "Verify continuation consistency") \
1942 \
1943 develop(bool, UseContinuationFastPath, true, \
1944 "Use fast-path frame walking in continuations") \
1945 \
1946 develop(int, VerifyMetaspaceInterval, DEBUG_ONLY(500) NOT_DEBUG(0), \
1947 "Run periodic metaspace verifications (0 - none, " \
1948 "1 - always, >1 every nth interval)") \
1949 \
1950 product(bool, ShowRegistersOnAssert, true, DIAGNOSTIC, \
1951 "On internal errors, include registers in error report.") \
1952 \
1953 product(bool, UseSwitchProfiling, true, DIAGNOSTIC, \
1954 "leverage profiling for table/lookup switch") \
1955 \
1956 develop(bool, TraceMemoryWriteback, false, \
1957 "Trace memory writeback operations") \
1958 \
1959 JFR_ONLY(product(bool, FlightRecorder, false, \
1960 "(Deprecated) Enable Flight Recorder")) \
1961 \
1962 JFR_ONLY(product(ccstr, FlightRecorderOptions, nullptr, \
1963 "Flight Recorder options")) \
1964 \
1965 JFR_ONLY(product(ccstr, StartFlightRecording, nullptr, \
1966 "Start flight recording with options")) \
1967 \
1968 product(bool, UseFastUnorderedTimeStamps, false, EXPERIMENTAL, \
1969 "Use platform unstable time where supported for timestamps only") \
1970 \
1971 product(bool, UseEmptySlotsInSupers, true, \
1972 "Allow allocating fields in empty slots of super-classes") \
1973 \
1974 product(bool, DeoptimizeNMethodBarriersALot, false, DIAGNOSTIC, \
1975 "Make nmethod barriers deoptimise a lot.") \
1976 \
1977 develop(bool, VerifyCrossModifyFence, \
1978 false AARCH64_ONLY(DEBUG_ONLY(||true)), \
1979 "Mark all threads after a safepoint, and clear on a modify " \
1980 "fence. Add cleanliness checks.") \
1981 \
1982 product(int, LockingMode, LM_LIGHTWEIGHT, \
1983 "Select locking mode: " \
1984 "0: monitors only (LM_MONITOR), " \
1985 "1: monitors & legacy stack-locking (LM_LEGACY), " \
1986 "2: monitors & new lightweight locking (LM_LIGHTWEIGHT, default)") \
1987 range(0, 2) \
1988 \
1989 product(bool, OMUseC2Cache, true, "") \
1990 \
1991 product(bool, OMC2UnrollCacheLookupLoopTail, true, "") \
1992 \
1993 product(int, OMC2UnrollCacheEntries, 0, "") \
1994 range(0, OMCache::CAPACITY) \
1995 \
1996 product(int, OMCacheSize, 8, "") \
1997 range(0, OMCache::CAPACITY) \
1998 \
1999 product(bool, OMShrinkCHT, false, "") \
2000 \
2001 product(int, OMSpins, 20, "") \
2002 \
2003 product(int, OMYields, 5, "") \
2004 \
2005 product(bool, OMCacheHitRate, false, "") \
2006 \
2007 product(bool, OMRecursiveFastPath, true, "Inflated recursion check first")\
2008 \
2009 product(uint, TrimNativeHeapInterval, 0, \
2010 "Interval, in ms, at which the JVM will trim the native heap if " \
2011 "the platform supports that. Lower values will reclaim memory " \
2012 "more eagerly at the cost of higher overhead. A value of 0 " \
2013 "(default) disables native heap trimming.") \
2014 range(0, UINT_MAX) \
2015 \
2016 develop(bool, SimulateFullAddressSpace, false, \
2017 "Simulates a very populated, fragmented address space; no " \
2018 "targeted reservations will succeed.") \
2019 \
2020 product(bool, ProfileExceptionHandlers, true, \
2021 "Profile exception handlers") \
2022 \
2023 product(bool, AlwaysRecordEvolDependencies, true, EXPERIMENTAL, \
2024 "Unconditionally record nmethod dependencies on class " \
2025 "rewriting/transformation independently of the JVMTI " \
2026 "can_{retransform/redefine}_classes capabilities.") \
2027
2028 // end of RUNTIME_FLAGS
2029
2030 DECLARE_FLAGS(LP64_RUNTIME_FLAGS)
2031 DECLARE_ARCH_FLAGS(ARCH_FLAGS)
2032 DECLARE_FLAGS(RUNTIME_FLAGS)
2033 DECLARE_FLAGS(RUNTIME_OS_FLAGS)
2034
2035 #endif // SHARE_RUNTIME_GLOBALS_HPP