1 /*
2 * Copyright (c) 1997, 2023, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation.
8 *
9 * This code is distributed in the hope that it will be useful, but WITHOUT
10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
12 * version 2 for more details (a copy is included in the LICENSE file that
13 * accompanied this code).
14 *
15 * You should have received a copy of the GNU General Public License version
16 * 2 along with this work; if not, write to the Free Software Foundation,
17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
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20 * or visit www.oracle.com if you need additional information or have any
21 * questions.
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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 // notproduct flags are settable / visible only during development and are not declared in the PRODUCT version
40 // develop_pd/product_pd flags are the same as develop/product, except that their default values
41 // are specified in platform-dependent header files.
42
43 // Flags must be declared with the following number of parameters:
44 // non-pd flags:
45 // (type, name, default_value, doc), or
46 // (type, name, default_value, extra_attrs, doc)
47 // pd flags:
48 // (type, name, doc), or
49 // (type, name, extra_attrs, doc)
50
51 // A flag must be declared with one of the following types:
52 // bool, int, uint, intx, uintx, size_t, ccstr, ccstrlist, double, or uint64_t.
53 // The type "ccstr" and "ccstrlist" are an alias for "const char*" and is used
54 // only in this file, because the macrology requires single-token type names.
55
56 // The optional extra_attrs parameter may have one of the following values:
57 // DIAGNOSTIC, EXPERIMENTAL, or MANAGEABLE. Currently extra_attrs can be used
58 // only with product/product_pd flags.
59 //
60 // DIAGNOSTIC options are not meant for VM tuning or for product modes.
61 // They are to be used for VM quality assurance or field diagnosis
62 // of VM bugs. They are hidden so that users will not be encouraged to
63 // try them as if they were VM ordinary execution options. However, they
64 // are available in the product version of the VM. Under instruction
65 // from support engineers, VM customers can turn them on to collect
66 // diagnostic information about VM problems. To use a VM diagnostic
67 // option, you must first specify +UnlockDiagnosticVMOptions.
68 // (This master switch also affects the behavior of -Xprintflags.)
69 //
70 // EXPERIMENTAL flags are in support of features that may not be
71 // an officially supported part of a product, but may be available
72 // for experimenting with. They could, for example, be performance
73 // features that may not have undergone full or rigorous QA, but which may
74 // help performance in some cases and released for experimentation
75 // by the community of users and developers. This flag also allows one to
76 // be able to build a fully supported product that nonetheless also
77 // ships with some unsupported, lightly tested, experimental features.
78 // Refer to the documentation of any products using this code for details
79 // on support and fitness for production.
80 // Like the UnlockDiagnosticVMOptions flag above, there is a corresponding
81 // UnlockExperimentalVMOptions flag, which allows the control and
82 // modification of the experimental flags.
83 //
84 // Nota bene: neither diagnostic nor experimental options should be used casually,
85 // Refer to the documentation of any products using this code for details.
86 //
87 // MANAGEABLE flags are writeable external product flags.
88 // They are dynamically writeable through the JDK management interface
89 // (com.sun.management.HotSpotDiagnosticMXBean API) and also through JConsole.
90 // These flags are external exported interface (see CSR). The list of
91 // manageable flags can be queried programmatically through the management
92 // interface.
93 //
94 // A flag can be made as "manageable" only if
95 // - the flag is defined in a CSR request as an external exported interface.
96 // - the VM implementation supports dynamic setting of the flag.
97 // This implies that the VM must *always* query the flag variable
98 // and not reuse state related to the flag state at any given time.
99 // - you want the flag to be queried programmatically by the customers.
100 //
101
102 //
103 // range is a macro that will expand to min and max arguments for range
104 // checking code if provided - see jvmFlagLimit.hpp
105 //
106 // constraint is a macro that will expand to custom function call
107 // for constraint checking if provided - see jvmFlagLimit.hpp
108
109 // Default and minimum StringTable and SymbolTable size values
110 // Must be powers of 2
111 const size_t defaultStringTableSize = NOT_LP64(1024) LP64_ONLY(65536);
112 const size_t minimumStringTableSize = 128;
113 const size_t defaultSymbolTableSize = 32768; // 2^15
114 const size_t minimumSymbolTableSize = 1024;
115
116 #ifdef _LP64
117 #define LP64_RUNTIME_FLAGS(develop, \
118 develop_pd, \
119 product, \
120 product_pd, \
121 notproduct, \
122 range, \
123 constraint) \
124 \
125 product(bool, UseCompressedOops, false, \
126 "Use 32-bit object references in 64-bit VM. " \
127 "lp64_product means flag is always constant in 32 bit VM") \
128 \
129 product(bool, UseCompressedClassPointers, true, \
130 "Use 32-bit class pointers in 64-bit VM. " \
131 "lp64_product means flag is always constant in 32 bit VM") \
132 \
133 product(int, ObjectAlignmentInBytes, 8, \
134 "Default object alignment in bytes, 8 is minimum") \
135 range(8, 256) \
136 constraint(ObjectAlignmentInBytesConstraintFunc, AtParse)
137
138 #else
139 // !_LP64
140
141 #define LP64_RUNTIME_FLAGS(develop, \
142 develop_pd, \
143 product, \
144 product_pd, \
145 notproduct, \
146 range, \
147 constraint)
148 const bool UseCompressedOops = false;
149 const bool UseCompressedClassPointers = false;
150 const int ObjectAlignmentInBytes = 8;
151
152 #endif // _LP64
153
154 #define RUNTIME_FLAGS(develop, \
155 develop_pd, \
156 product, \
157 product_pd, \
158 notproduct, \
159 range, \
160 constraint) \
161 \
162 notproduct(bool, CheckCompressedOops, true, \
163 "Generate checks in encoding/decoding code in debug VM") \
164 \
165 product(uintx, HeapSearchSteps, 3 PPC64_ONLY(+17), \
166 "Heap allocation steps through preferred address regions to find" \
167 " where it can allocate the heap. Number of steps to take per " \
168 "region.") \
169 range(1, max_uintx) \
170 \
171 product(uint, HandshakeTimeout, 0, DIAGNOSTIC, \
172 "If nonzero set a timeout in milliseconds for handshakes") \
173 \
174 product(bool, AlwaysSafeConstructors, false, EXPERIMENTAL, \
175 "Force safe construction, as if all fields are final.") \
176 \
177 product(bool, UnlockDiagnosticVMOptions, trueInDebug, DIAGNOSTIC, \
178 "Enable normal processing of flags relating to field diagnostics")\
179 \
180 product(bool, UnlockExperimentalVMOptions, false, EXPERIMENTAL, \
181 "Enable normal processing of flags relating to experimental " \
182 "features") \
183 \
184 product(bool, JavaMonitorsInStackTrace, true, \
185 "Print information about Java monitor locks when the stacks are " \
186 "dumped") \
187 \
188 product_pd(bool, UseLargePages, \
189 "Use large page memory") \
190 \
191 product_pd(bool, UseLargePagesIndividualAllocation, \
192 "Allocate large pages individually for better affinity") \
193 \
194 develop(bool, LargePagesIndividualAllocationInjectError, false, \
195 "Fail large pages individual allocation") \
196 \
197 product(bool, UseNUMA, false, \
198 "Use NUMA if available") \
199 \
200 product(bool, UseNUMAInterleaving, false, \
201 "Interleave memory across NUMA nodes if available") \
202 \
203 product(size_t, NUMAInterleaveGranularity, 2*M, \
204 "Granularity to use for NUMA interleaving on Windows OS") \
205 constraint(NUMAInterleaveGranularityConstraintFunc, AtParse) \
206 \
207 product(uintx, NUMAChunkResizeWeight, 20, \
208 "Percentage (0-100) used to weight the current sample when " \
209 "computing exponentially decaying average for " \
210 "AdaptiveNUMAChunkSizing") \
211 range(0, 100) \
212 \
213 product(size_t, NUMASpaceResizeRate, 1*G, \
214 "Do not reallocate more than this amount per collection") \
215 range(0, max_uintx) \
216 \
217 product(bool, UseAdaptiveNUMAChunkSizing, true, \
218 "Enable adaptive chunk sizing for NUMA") \
219 \
220 product(bool, NUMAStats, false, \
221 "Print NUMA stats in detailed heap information") \
222 \
223 product(uintx, NUMAPageScanRate, 256, \
224 "Maximum number of pages to include in the page scan procedure") \
225 range(0, max_uintx) \
226 \
227 product(bool, UseAES, false, \
228 "Control whether AES instructions are used when available") \
229 \
230 product(bool, UseFMA, false, \
231 "Control whether FMA instructions are used when available") \
232 \
233 product(bool, UseSHA, false, \
234 "Control whether SHA instructions are used when available") \
235 \
236 product(bool, UseGHASHIntrinsics, false, DIAGNOSTIC, \
237 "Use intrinsics for GHASH versions of crypto") \
238 \
239 product(bool, UseBASE64Intrinsics, false, \
240 "Use intrinsics for java.util.Base64") \
241 \
242 product(bool, UsePoly1305Intrinsics, false, DIAGNOSTIC, \
243 "Use intrinsics for sun.security.util.math.intpoly") \
244 \
245 product(size_t, LargePageSizeInBytes, 0, \
246 "Maximum large page size used (0 will use the default large " \
247 "page size for the environment as the maximum)") \
248 range(0, max_uintx) \
249 \
250 product(size_t, LargePageHeapSizeThreshold, 128*M, \
251 "Use large pages if maximum heap is at least this big") \
252 range(0, max_uintx) \
253 \
254 product(bool, ForceTimeHighResolution, false, \
255 "Using high time resolution (for Win32 only)") \
256 \
257 develop(bool, TracePcPatching, false, \
258 "Trace usage of frame::patch_pc") \
259 \
260 develop(bool, TraceRelocator, false, \
261 "Trace the bytecode relocator") \
262 \
263 \
264 product(bool, SafepointALot, false, DIAGNOSTIC, \
265 "Generate a lot of safepoints. This works with " \
266 "GuaranteedSafepointInterval") \
267 \
268 product(bool, HandshakeALot, false, DIAGNOSTIC, \
269 "Generate a lot of handshakes. This works with " \
270 "GuaranteedSafepointInterval") \
271 \
272 product_pd(bool, BackgroundCompilation, \
273 "A thread requesting compilation is not blocked during " \
274 "compilation") \
275 \
276 product(bool, MethodFlushing, true, \
277 "Reclamation of compiled methods") \
278 \
279 develop(bool, VerifyStack, false, \
280 "Verify stack of each thread when it is entering a runtime call") \
281 \
282 product(bool, ForceUnreachable, false, DIAGNOSTIC, \
283 "Make all non code cache addresses to be unreachable by " \
284 "forcing use of 64bit literal fixups") \
285 \
286 develop(bool, TraceDerivedPointers, false, \
287 "Trace traversal of derived pointers on stack") \
288 \
289 notproduct(bool, TraceCodeBlobStacks, false, \
290 "Trace stack-walk of codeblobs") \
291 \
292 notproduct(bool, PrintRewrites, false, \
293 "Print methods that are being rewritten") \
294 \
295 product(bool, UseInlineCaches, true, \
296 "Use Inline Caches for virtual calls ") \
297 \
298 product(bool, InlineArrayCopy, true, DIAGNOSTIC, \
299 "Inline arraycopy native that is known to be part of " \
300 "base library DLL") \
301 \
302 product(bool, InlineObjectHash, true, DIAGNOSTIC, \
303 "Inline Object::hashCode() native that is known to be part " \
304 "of base library DLL") \
305 \
306 product(bool, InlineNatives, true, DIAGNOSTIC, \
307 "Inline natives that are known to be part of base library DLL") \
308 \
309 product(bool, InlineMathNatives, true, DIAGNOSTIC, \
310 "Inline SinD, CosD, etc.") \
311 \
312 product(bool, InlineClassNatives, true, DIAGNOSTIC, \
313 "Inline Class.isInstance, etc") \
314 \
315 product(bool, InlineThreadNatives, true, DIAGNOSTIC, \
316 "Inline Thread.currentThread, etc") \
317 \
318 product(bool, InlineUnsafeOps, true, DIAGNOSTIC, \
319 "Inline memory ops (native methods) from Unsafe") \
320 \
321 product(bool, UseAESIntrinsics, false, DIAGNOSTIC, \
322 "Use intrinsics for AES versions of crypto") \
323 \
324 product(bool, UseAESCTRIntrinsics, false, DIAGNOSTIC, \
325 "Use intrinsics for the paralleled version of AES/CTR crypto") \
326 \
327 product(bool, UseChaCha20Intrinsics, false, DIAGNOSTIC, \
328 "Use intrinsics for the vectorized version of ChaCha20") \
329 \
330 product(bool, UseMD5Intrinsics, false, DIAGNOSTIC, \
331 "Use intrinsics for MD5 crypto hash function") \
332 \
333 product(bool, UseSHA1Intrinsics, false, DIAGNOSTIC, \
334 "Use intrinsics for SHA-1 crypto hash function. " \
335 "Requires that UseSHA is enabled.") \
336 \
337 product(bool, UseSHA256Intrinsics, false, DIAGNOSTIC, \
338 "Use intrinsics for SHA-224 and SHA-256 crypto hash functions. " \
339 "Requires that UseSHA is enabled.") \
340 \
341 product(bool, UseSHA512Intrinsics, false, DIAGNOSTIC, \
342 "Use intrinsics for SHA-384 and SHA-512 crypto hash functions. " \
343 "Requires that UseSHA is enabled.") \
344 \
345 product(bool, UseSHA3Intrinsics, false, DIAGNOSTIC, \
346 "Use intrinsics for SHA3 crypto hash function. " \
347 "Requires that UseSHA is enabled.") \
348 \
349 product(bool, UseCRC32Intrinsics, false, DIAGNOSTIC, \
350 "use intrinsics for java.util.zip.CRC32") \
351 \
352 product(bool, UseCRC32CIntrinsics, false, DIAGNOSTIC, \
353 "use intrinsics for java.util.zip.CRC32C") \
354 \
355 product(bool, UseAdler32Intrinsics, false, DIAGNOSTIC, \
356 "use intrinsics for java.util.zip.Adler32") \
357 \
358 product(bool, UseVectorizedMismatchIntrinsic, false, DIAGNOSTIC, \
359 "Enables intrinsification of ArraysSupport.vectorizedMismatch()") \
360 \
361 product(bool, UseVectorizedHashCodeIntrinsic, false, DIAGNOSTIC, \
362 "Enables intrinsification of ArraysSupport.vectorizedHashCode()") \
363 \
364 product(bool, UseCopySignIntrinsic, false, DIAGNOSTIC, \
365 "Enables intrinsification of Math.copySign") \
366 \
367 product(bool, UseSignumIntrinsic, false, DIAGNOSTIC, \
368 "Enables intrinsification of Math.signum") \
369 \
370 product_pd(bool, DelayCompilerStubsGeneration, DIAGNOSTIC, \
371 "Use Compiler thread for compiler's stubs generation") \
372 \
373 product(ccstrlist, DisableIntrinsic, "", DIAGNOSTIC, \
374 "do not expand intrinsics whose (internal) names appear here") \
375 constraint(DisableIntrinsicConstraintFunc,AfterErgo) \
376 \
377 product(ccstrlist, ControlIntrinsic, "", DIAGNOSTIC, \
378 "Control intrinsics using a list of +/- (internal) names, " \
379 "separated by commas") \
380 constraint(ControlIntrinsicConstraintFunc,AfterErgo) \
381 \
382 develop(bool, TraceCallFixup, false, \
383 "Trace all call fixups") \
384 \
385 develop(bool, DeoptimizeALot, false, \
386 "Deoptimize at every exit from the runtime system") \
387 \
388 notproduct(ccstrlist, DeoptimizeOnlyAt, "", \
389 "A comma separated list of bcis to deoptimize at") \
390 \
391 develop(bool, DeoptimizeRandom, false, \
392 "Deoptimize random frames on random exit from the runtime system")\
393 \
394 notproduct(bool, ZombieALot, false, \
395 "Create non-entrant nmethods at exit from the runtime system") \
396 \
397 notproduct(bool, WalkStackALot, false, \
398 "Trace stack (no print) at every exit from the runtime system") \
399 \
400 develop(bool, DeoptimizeObjectsALot, false, \
401 "For testing purposes concurrent threads revert optimizations " \
402 "based on escape analysis at intervals given with " \
403 "DeoptimizeObjectsALotInterval=n. The thread count is given " \
404 "with DeoptimizeObjectsALotThreadCountSingle and " \
405 "DeoptimizeObjectsALotThreadCountAll.") \
406 \
407 develop(uint64_t, DeoptimizeObjectsALotInterval, 5, \
408 "Interval for DeoptimizeObjectsALot.") \
409 range(0, max_jlong) \
410 \
411 develop(int, DeoptimizeObjectsALotThreadCountSingle, 1, \
412 "The number of threads that revert optimizations based on " \
413 "escape analysis for a single thread if DeoptimizeObjectsALot " \
414 "is enabled. The target thread is selected round robin." ) \
415 range(0, max_jint) \
416 \
417 develop(int, DeoptimizeObjectsALotThreadCountAll, 1, \
418 "The number of threads that revert optimizations based on " \
419 "escape analysis for all threads if DeoptimizeObjectsALot " \
420 "is enabled." ) \
421 range(0, max_jint) \
422 \
423 notproduct(bool, VerifyLastFrame, false, \
424 "Verify oops on last frame on entry to VM") \
425 \
426 product(bool, SafepointTimeout, false, \
427 "Time out and warn or fail after SafepointTimeoutDelay " \
428 "milliseconds if failed to reach safepoint") \
429 \
430 product(bool, AbortVMOnSafepointTimeout, false, DIAGNOSTIC, \
431 "Abort upon failure to reach safepoint (see SafepointTimeout)") \
432 \
433 product(bool, AbortVMOnVMOperationTimeout, false, DIAGNOSTIC, \
434 "Abort upon failure to complete VM operation promptly") \
435 \
436 product(intx, AbortVMOnVMOperationTimeoutDelay, 1000, DIAGNOSTIC, \
437 "Delay in milliseconds for option AbortVMOnVMOperationTimeout") \
438 range(0, max_intx) \
439 \
440 product(bool, MaxFDLimit, true, \
441 "Bump the number of file descriptors to maximum (Unix only)") \
442 \
443 product(bool, LogEvents, true, DIAGNOSTIC, \
444 "Enable the various ring buffer event logs") \
445 \
446 product(uintx, LogEventsBufferEntries, 20, DIAGNOSTIC, \
447 "Number of ring buffer event logs") \
448 range(1, NOT_LP64(1*K) LP64_ONLY(1*M)) \
449 \
450 product(bool, BytecodeVerificationRemote, true, DIAGNOSTIC, \
451 "Enable the Java bytecode verifier for remote classes") \
452 \
453 product(bool, BytecodeVerificationLocal, false, DIAGNOSTIC, \
454 "Enable the Java bytecode verifier for local classes") \
455 \
456 develop(bool, VerifyStackAtCalls, false, \
457 "Verify that the stack pointer is unchanged after calls") \
458 \
459 develop(bool, TraceJavaAssertions, false, \
460 "Trace java language assertions") \
461 \
462 notproduct(bool, VerifyCodeCache, false, \
463 "Verify code cache on memory allocation/deallocation") \
464 \
465 develop(bool, ZapResourceArea, trueInDebug, \
466 "Zap freed resource/arena space") \
467 \
468 notproduct(bool, ZapVMHandleArea, trueInDebug, \
469 "Zap freed VM handle space") \
470 \
471 notproduct(bool, ZapStackSegments, trueInDebug, \
472 "Zap allocated/freed stack segments") \
473 \
474 develop(bool, ZapUnusedHeapArea, trueInDebug, \
475 "Zap unused heap space") \
476 \
477 develop(bool, CheckZapUnusedHeapArea, false, \
478 "Check zapping of unused heap space") \
479 \
480 develop(bool, ZapFillerObjects, trueInDebug, \
481 "Zap filler objects") \
482 \
483 product(bool, ExecutingUnitTests, false, \
484 "Whether the JVM is running unit tests or not") \
485 \
486 develop(uint, ErrorHandlerTest, 0, \
487 "If > 0, provokes an error after VM initialization; the value " \
488 "determines which error to provoke. See controlled_crash() " \
489 "in vmError.cpp.") \
490 range(0, 17) \
491 \
492 develop(uint, TestCrashInErrorHandler, 0, \
493 "If > 0, provokes an error inside VM error handler (a secondary " \
494 "crash). see controlled_crash() in vmError.cpp") \
495 range(0, 17) \
496 \
497 develop(bool, TestSafeFetchInErrorHandler, false , \
498 "If true, tests SafeFetch inside error handler.") \
499 \
500 develop(bool, TestUnresponsiveErrorHandler, false, \
501 "If true, simulates an unresponsive error handler.") \
502 \
503 develop(bool, Verbose, false, \
504 "Print additional debugging information from other modes") \
505 \
506 develop(bool, PrintMiscellaneous, false, \
507 "Print uncategorized debugging information (requires +Verbose)") \
508 \
509 develop(bool, WizardMode, false, \
510 "Print much more debugging information") \
511 \
512 product(bool, ShowMessageBoxOnError, false, \
513 "Keep process alive on VM fatal error") \
514 \
515 product(bool, CreateCoredumpOnCrash, true, \
516 "Create core/mini dump on VM fatal error") \
517 \
518 product(uint64_t, ErrorLogTimeout, 2 * 60, \
519 "Timeout, in seconds, to limit the time spent on writing an " \
520 "error log in case of a crash.") \
521 range(0, (uint64_t)max_jlong/1000) \
522 \
523 product(bool, ErrorLogSecondaryErrorDetails, false, DIAGNOSTIC, \
524 "If enabled, show details on secondary crashes in the error log") \
525 \
526 develop(intx, TraceDwarfLevel, 0, \
527 "Debug levels for the dwarf parser") \
528 range(0, 4) \
529 \
530 product(bool, SuppressFatalErrorMessage, false, \
531 "Report NO fatal error message (avoid deadlock)") \
532 \
533 product(ccstrlist, OnError, "", \
534 "Run user-defined commands on fatal error; see VMError.cpp " \
535 "for examples") \
536 \
537 product(ccstrlist, OnOutOfMemoryError, "", \
538 "Run user-defined commands on first java.lang.OutOfMemoryError " \
539 "thrown from JVM") \
540 \
541 product(bool, HeapDumpBeforeFullGC, false, MANAGEABLE, \
542 "Dump heap to file before any major stop-the-world GC") \
543 \
544 product(bool, HeapDumpAfterFullGC, false, MANAGEABLE, \
545 "Dump heap to file after any major stop-the-world GC") \
546 \
547 product(bool, HeapDumpOnOutOfMemoryError, false, MANAGEABLE, \
548 "Dump heap to file when java.lang.OutOfMemoryError is thrown " \
549 "from JVM") \
550 \
551 product(ccstr, HeapDumpPath, nullptr, MANAGEABLE, \
552 "When HeapDumpOnOutOfMemoryError is on, the path (filename or " \
553 "directory) of the dump file (defaults to java_pid<pid>.hprof " \
554 "in the working directory)") \
555 \
556 product(intx, HeapDumpGzipLevel, 0, MANAGEABLE, \
557 "When HeapDumpOnOutOfMemoryError is on, the gzip compression " \
558 "level of the dump file. 0 (the default) disables gzip " \
559 "compression. Otherwise the level must be between 1 and 9.") \
560 range(0, 9) \
561 \
562 product(ccstr, NativeMemoryTracking, DEBUG_ONLY("summary") NOT_DEBUG("off"), \
563 "Native memory tracking options") \
564 \
565 product(bool, PrintNMTStatistics, false, DIAGNOSTIC, \
566 "Print native memory tracking summary data if it is on") \
567 \
568 product(bool, LogCompilation, false, DIAGNOSTIC, \
569 "Log compilation activity in detail to LogFile") \
570 \
571 product(bool, PrintCompilation, false, \
572 "Print compilations") \
573 \
574 product(intx, RepeatCompilation, 0, DIAGNOSTIC, \
575 "Repeat compilation without installing code (number of times)") \
576 range(0, max_jint) \
577 \
578 product(bool, PrintExtendedThreadInfo, false, \
579 "Print more information in thread dump") \
580 \
581 product(intx, ScavengeRootsInCode, 2, DIAGNOSTIC, \
582 "0: do not allow scavengable oops in the code cache; " \
583 "1: allow scavenging from the code cache; " \
584 "2: emit as many constants as the compiler can see") \
585 range(0, 2) \
586 \
587 product(bool, AlwaysRestoreFPU, false, \
588 "Restore the FPU control word after every JNI call (expensive)") \
589 \
590 product(bool, PrintCompilation2, false, DIAGNOSTIC, \
591 "Print additional statistics per compilation") \
592 \
593 product(bool, PrintAdapterHandlers, false, DIAGNOSTIC, \
594 "Print code generated for i2c/c2i adapters") \
595 \
596 product(bool, VerifyAdapterCalls, trueInDebug, DIAGNOSTIC, \
597 "Verify that i2c/c2i adapters are called properly") \
598 \
599 develop(bool, VerifyAdapterSharing, false, \
600 "Verify that the code for shared adapters is the equivalent") \
601 \
602 product(bool, PrintAssembly, false, DIAGNOSTIC, \
603 "Print assembly code (using external disassembler.so)") \
604 \
605 product(ccstr, PrintAssemblyOptions, nullptr, DIAGNOSTIC, \
606 "Print options string passed to disassembler.so") \
607 \
608 notproduct(bool, PrintNMethodStatistics, false, \
609 "Print a summary statistic for the generated nmethods") \
610 \
611 product(bool, PrintNMethods, false, DIAGNOSTIC, \
612 "Print assembly code for nmethods when generated") \
613 \
614 product(bool, PrintNativeNMethods, false, DIAGNOSTIC, \
615 "Print assembly code for native nmethods when generated") \
616 \
617 develop(bool, PrintDebugInfo, false, \
618 "Print debug information for all nmethods when generated") \
619 \
620 develop(bool, PrintRelocations, false, \
621 "Print relocation information for all nmethods when generated") \
622 \
623 develop(bool, PrintDependencies, false, \
624 "Print dependency information for all nmethods when generated") \
625 \
626 develop(bool, PrintExceptionHandlers, false, \
627 "Print exception handler tables for all nmethods when generated") \
628 \
629 develop(bool, StressCompiledExceptionHandlers, false, \
630 "Exercise compiled exception handlers") \
631 \
632 develop(bool, InterceptOSException, false, \
633 "Start debugger when an implicit OS (e.g. null pointer) " \
634 "exception happens") \
635 \
636 product(bool, PrintCodeCache, false, \
637 "Print the code cache memory usage when exiting") \
638 \
639 develop(bool, PrintCodeCache2, false, \
640 "Print detailed usage information on the code cache when exiting")\
641 \
642 product(bool, PrintCodeCacheOnCompilation, false, \
643 "Print the code cache memory usage each time a method is " \
644 "compiled") \
645 \
646 product(bool, PrintCodeHeapAnalytics, false, DIAGNOSTIC, \
647 "Print code heap usage statistics on exit and on full condition") \
648 \
649 product(bool, PrintStubCode, false, DIAGNOSTIC, \
650 "Print generated stub code") \
651 \
652 product(bool, StackTraceInThrowable, true, \
653 "Collect backtrace in throwable when exception happens") \
654 \
655 product(bool, OmitStackTraceInFastThrow, true, \
656 "Omit backtraces for some 'hot' exceptions in optimized code") \
657 \
658 product(bool, ShowCodeDetailsInExceptionMessages, true, MANAGEABLE, \
659 "Show exception messages from RuntimeExceptions that contain " \
660 "snippets of the failing code. Disable this to improve privacy.") \
661 \
662 product(bool, PrintWarnings, true, \
663 "Print JVM warnings to output stream") \
664 \
665 product(bool, RegisterFinalizersAtInit, true, \
666 "Register finalizable objects at end of Object.<init> or " \
667 "after allocation") \
668 \
669 develop(bool, RegisterReferences, true, \
670 "Tell whether the VM should register soft/weak/final/phantom " \
671 "references") \
672 \
673 develop(bool, PrintCodeCacheExtension, false, \
674 "Print extension of code cache") \
675 \
676 develop(bool, UsePrivilegedStack, true, \
677 "Enable the security JVM functions") \
678 \
679 product(bool, ClassUnloading, true, \
680 "Do unloading of classes") \
681 \
682 product(bool, ClassUnloadingWithConcurrentMark, true, \
683 "Do unloading of classes with a concurrent marking cycle") \
684 \
685 notproduct(bool, PrintSystemDictionaryAtExit, false, \
686 "Print the system dictionary at exit") \
687 \
688 notproduct(bool, PrintClassLoaderDataGraphAtExit, false, \
689 "Print the class loader data graph at exit") \
690 \
691 product(bool, AllowParallelDefineClass, false, \
692 "Allow parallel defineClass requests for class loaders " \
693 "registering as parallel capable") \
694 \
695 product_pd(bool, DontYieldALot, \
696 "Throw away obvious excess yield calls") \
697 \
698 product(bool, DisablePrimordialThreadGuardPages, false, EXPERIMENTAL, \
699 "Disable the use of stack guard pages if the JVM is loaded " \
700 "on the primordial process thread") \
701 \
702 product(bool, DoJVMTIVirtualThreadTransitions, true, EXPERIMENTAL, \
703 "Do JVMTI virtual thread mount/unmount transitions " \
704 "(disabling this flag implies no JVMTI events are posted)") \
705 \
706 /* notice: the max range value here is max_jint, not max_intx */ \
707 /* because of overflow issue */ \
708 product(intx, AsyncDeflationInterval, 250, DIAGNOSTIC, \
709 "Async deflate idle monitors every so many milliseconds when " \
710 "MonitorUsedDeflationThreshold is exceeded (0 is off).") \
711 range(0, max_jint) \
712 \
713 /* notice: the max range value here is max_jint, not max_intx */ \
714 /* because of overflow issue */ \
715 product(intx, GuaranteedAsyncDeflationInterval, 60000, DIAGNOSTIC, \
716 "Async deflate idle monitors every so many milliseconds even " \
717 "when MonitorUsedDeflationThreshold is NOT exceeded (0 is off).") \
718 range(0, max_jint) \
719 \
720 product(size_t, AvgMonitorsPerThreadEstimate, 1024, DIAGNOSTIC, \
721 "Used to estimate a variable ceiling based on number of threads " \
722 "for use with MonitorUsedDeflationThreshold (0 is off).") \
723 range(0, max_uintx) \
724 \
725 /* notice: the max range value here is max_jint, not max_intx */ \
726 /* because of overflow issue */ \
727 product(intx, MonitorDeflationMax, 1000000, DIAGNOSTIC, \
728 "The maximum number of monitors to deflate, unlink and delete " \
729 "at one time (minimum is 1024).") \
730 range(1024, max_jint) \
731 \
732 product(intx, MonitorUsedDeflationThreshold, 90, DIAGNOSTIC, \
733 "Percentage of used monitors before triggering deflation (0 is " \
734 "off). The check is performed on GuaranteedSafepointInterval, " \
735 "AsyncDeflationInterval or GuaranteedAsyncDeflationInterval, " \
736 "whichever is lower.") \
737 range(0, 100) \
738 \
739 product(uintx, NoAsyncDeflationProgressMax, 3, DIAGNOSTIC, \
740 "Max number of no progress async deflation attempts to tolerate " \
741 "before adjusting the in_use_list_ceiling up (0 is off).") \
742 range(0, max_uintx) \
743 \
744 product(intx, hashCode, 5, EXPERIMENTAL, \
745 "(Unstable) select hashCode generation algorithm") \
746 \
747 product(bool, ReduceSignalUsage, false, \
748 "Reduce the use of OS signals in Java and/or the VM") \
749 \
750 develop(bool, LoadLineNumberTables, true, \
751 "Tell whether the class file parser loads line number tables") \
752 \
753 develop(bool, LoadLocalVariableTables, true, \
754 "Tell whether the class file parser loads local variable tables") \
755 \
756 develop(bool, LoadLocalVariableTypeTables, true, \
757 "Tell whether the class file parser loads local variable type" \
758 "tables") \
759 \
760 product(bool, AllowUserSignalHandlers, false, \
761 "Application will install primary signal handlers for the JVM " \
762 "(Unix only)") \
763 \
764 product(bool, UseSignalChaining, true, \
765 "Use signal-chaining to invoke signal handlers installed " \
766 "by the application (Unix only)") \
767 \
768 product(bool, RestoreMXCSROnJNICalls, false, \
769 "Restore MXCSR when returning from JNI calls") \
770 \
771 product(bool, CheckJNICalls, false, \
772 "Verify all arguments to JNI calls") \
773 \
774 product(bool, UseFastJNIAccessors, true, \
775 "Use optimized versions of Get<Primitive>Field") \
776 \
777 product(intx, MaxJNILocalCapacity, 65536, \
778 "Maximum allowable local JNI handle capacity to " \
779 "EnsureLocalCapacity() and PushLocalFrame(), " \
780 "where <= 0 is unlimited, default: 65536") \
781 range(min_intx, max_intx) \
782 \
783 product(bool, EagerXrunInit, false, \
784 "Eagerly initialize -Xrun libraries; allows startup profiling, " \
785 "but not all -Xrun libraries may support the state of the VM " \
786 "at this time") \
787 \
788 product(bool, PreserveAllAnnotations, false, \
789 "Preserve RuntimeInvisibleAnnotations as well " \
790 "as RuntimeVisibleAnnotations") \
791 \
792 develop(uintx, PreallocatedOutOfMemoryErrorCount, 4, \
793 "Number of OutOfMemoryErrors preallocated with backtrace") \
794 \
795 product(bool, UseXMMForArrayCopy, false, \
796 "Use SSE2 MOVQ instruction for Arraycopy") \
797 \
798 notproduct(bool, PrintFieldLayout, false, \
799 "Print field layout for each class") \
800 \
801 notproduct(bool, PrintInlineLayout, false, \
802 "Print field layout for each inline type") \
803 \
804 notproduct(bool, PrintFlatArrayLayout, false, \
805 "Print array layout for each inline type array") \
806 \
807 product(intx, FlatArrayElementMaxSize, -1, \
808 "Max size for flattening inline array elements, <0 no limit") \
809 \
810 product(intx, InlineFieldMaxFlatSize, 128, \
811 "Max size for flattening inline type fields, <0 no limit") \
812 \
813 product(intx, FlatArrayElementMaxOops, 4, \
814 "Max nof embedded object references in an inline type to flatten, <0 no limit") \
815 \
816 product(bool, InlineArrayAtomicAccess, false, \
817 "Atomic inline array accesses by-default, for all inline arrays") \
818 \
819 /* Need to limit the extent of the padding to reasonable size. */\
820 /* 8K is well beyond the reasonable HW cache line size, even with */\
821 /* aggressive prefetching, while still leaving the room for segregating */\
822 /* among the distinct pages. */\
823 product(intx, ContendedPaddingWidth, 128, \
824 "How many bytes to pad the fields/classes marked @Contended with")\
825 range(0, 8192) \
826 constraint(ContendedPaddingWidthConstraintFunc,AfterErgo) \
827 \
828 product(bool, EnableContended, true, \
829 "Enable @Contended annotation support") \
830 \
831 product(bool, RestrictContended, true, \
832 "Restrict @Contended to trusted classes") \
833 \
834 product(int, DiagnoseSyncOnValueBasedClasses, 0, DIAGNOSTIC, \
835 "Detect and take action upon identifying synchronization on " \
836 "value based classes. Modes: " \
837 "0: off; " \
838 "1: exit with fatal error; " \
839 "2: log message to stdout. Output file can be specified with " \
840 " -Xlog:valuebasedclasses. If JFR is running it will " \
841 " also generate JFR events.") \
842 range(0, 2) \
843 \
844 product(bool, ExitOnOutOfMemoryError, false, \
845 "JVM exits on the first occurrence of an out-of-memory error " \
846 "thrown from JVM") \
847 \
848 product(bool, CrashOnOutOfMemoryError, false, \
849 "JVM aborts, producing an error log and core/mini dump, on the " \
850 "first occurrence of an out-of-memory error thrown from JVM") \
851 \
852 /* tracing */ \
853 \
854 develop(bool, StressRewriter, false, \
855 "Stress linktime bytecode rewriting") \
856 \
857 product(ccstr, TraceJVMTI, nullptr, \
858 "Trace flags for JVMTI functions and events") \
859 \
860 product(bool, StressLdcRewrite, false, DIAGNOSTIC, \
861 "Force ldc -> ldc_w rewrite during RedefineClasses. " \
862 "This option can change an EMCP method into an obsolete method " \
863 "and can affect tests that expect specific methods to be EMCP. " \
864 "This option should be used with caution.") \
865 \
866 product(bool, AllowRedefinitionToAddDeleteMethods, false, \
867 "(Deprecated) Allow redefinition to add and delete private " \
868 "static or final methods for compatibility with old releases") \
869 \
870 develop(bool, TraceBytecodes, false, \
871 "Trace bytecode execution") \
872 \
873 develop(bool, TraceICs, false, \
874 "Trace inline cache changes") \
875 \
876 notproduct(bool, TraceInvocationCounterOverflow, false, \
877 "Trace method invocation counter overflow") \
878 \
879 develop(bool, TraceInlineCacheClearing, false, \
880 "Trace clearing of inline caches in nmethods") \
881 \
882 develop(bool, VerifyDependencies, trueInDebug, \
883 "Exercise and verify the compilation dependency mechanism") \
884 \
885 develop(bool, TraceNewOopMapGeneration, false, \
886 "Trace OopMapGeneration") \
887 \
888 develop(bool, TraceNewOopMapGenerationDetailed, false, \
889 "Trace OopMapGeneration: print detailed cell states") \
890 \
891 develop(bool, TimeOopMap, false, \
892 "Time calls to GenerateOopMap::compute_map() in sum") \
893 \
894 develop(bool, TimeOopMap2, false, \
895 "Time calls to GenerateOopMap::compute_map() individually") \
896 \
897 develop(bool, TraceOopMapRewrites, false, \
898 "Trace rewriting of methods during oop map generation") \
899 \
900 develop(bool, TraceICBuffer, false, \
901 "Trace usage of IC buffer") \
902 \
903 develop(bool, TraceCompiledIC, false, \
904 "Trace changes of compiled IC") \
905 \
906 develop(bool, FLSVerifyDictionary, false, \
907 "Do lots of (expensive) FLS dictionary verification") \
908 \
909 product(uintx, ProcessDistributionStride, 4, \
910 "Stride through processors when distributing processes") \
911 range(0, max_juint) \
912 \
913 develop(bool, TraceFinalizerRegistration, false, \
914 "Trace registration of final references") \
915 \
916 product(bool, IgnoreEmptyClassPaths, false, \
917 "Ignore empty path elements in -classpath") \
918 \
919 product(bool, PrintHeapAtSIGBREAK, true, \
920 "Print heap layout in response to SIGBREAK") \
921 \
922 product(bool, PrintClassHistogram, false, MANAGEABLE, \
923 "Print a histogram of class instances") \
924 \
925 product(double, ObjectCountCutOffPercent, 0.5, EXPERIMENTAL, \
926 "The percentage of the used heap that the instances of a class " \
927 "must occupy for the class to generate a trace event") \
928 range(0.0, 100.0) \
929 \
930 /* JVMTI heap profiling */ \
931 \
932 product(bool, VerifyBeforeIteration, false, DIAGNOSTIC, \
933 "Verify memory system before JVMTI iteration") \
934 \
935 /* compiler */ \
936 \
937 /* notice: the max range value here is max_jint, not max_intx */ \
938 /* because of overflow issue */ \
939 product(intx, CICompilerCount, CI_COMPILER_COUNT, \
940 "Number of compiler threads to run") \
941 range(0, max_jint) \
942 constraint(CICompilerCountConstraintFunc, AfterErgo) \
943 \
944 product(bool, UseDynamicNumberOfCompilerThreads, true, \
945 "Dynamically choose the number of parallel compiler threads") \
946 \
947 product(bool, ReduceNumberOfCompilerThreads, true, DIAGNOSTIC, \
948 "Reduce the number of parallel compiler threads when they " \
949 "are not used") \
950 \
951 product(bool, TraceCompilerThreads, false, DIAGNOSTIC, \
952 "Trace creation and removal of compiler threads") \
953 \
954 product(ccstr, LogClassLoadingCauseFor, nullptr, \
955 "Apply -Xlog:class+load+cause* to classes whose fully " \
956 "qualified name contains this string (\"*\" matches " \
957 "any class).") \
958 \
959 develop(bool, InjectCompilerCreationFailure, false, \
960 "Inject thread creation failures for " \
961 "UseDynamicNumberOfCompilerThreads") \
962 \
963 develop(bool, GenerateSynchronizationCode, true, \
964 "generate locking/unlocking code for synchronized methods and " \
965 "monitors") \
966 \
967 product_pd(bool, ImplicitNullChecks, DIAGNOSTIC, \
968 "Generate code for implicit null checks") \
969 \
970 product_pd(bool, TrapBasedNullChecks, \
971 "Generate code for null checks that uses a cmp and trap " \
972 "instruction raising SIGTRAP. This is only used if an access to" \
973 "null (+offset) will not raise a SIGSEGV, i.e.," \
974 "ImplicitNullChecks don't work (PPC64).") \
975 \
976 product(bool, EnableThreadSMRStatistics, trueInDebug, DIAGNOSTIC, \
977 "Enable Thread SMR Statistics") \
978 \
979 product(bool, UseNotificationThread, true, \
980 "Use Notification Thread") \
981 \
982 product(bool, Inline, true, \
983 "Enable inlining") \
984 \
985 product(bool, ClipInlining, true, \
986 "Clip inlining if aggregate method exceeds DesiredMethodLimit") \
987 \
988 develop(bool, UseCHA, true, \
989 "Enable CHA") \
990 \
991 product(bool, UseVtableBasedCHA, true, DIAGNOSTIC, \
992 "Use vtable information during CHA") \
993 \
994 product(bool, UseTypeProfile, true, \
995 "Check interpreter profile for historically monomorphic calls") \
996 \
997 product(bool, PrintInlining, false, DIAGNOSTIC, \
998 "Print inlining optimizations") \
999 \
1000 product(bool, UsePopCountInstruction, false, \
1001 "Use population count instruction") \
1002 \
1003 develop(bool, TraceMethodReplacement, false, \
1004 "Print when methods are replaced do to recompilation") \
1005 \
1006 product(bool, PrintMethodFlushingStatistics, false, DIAGNOSTIC, \
1007 "print statistics about method flushing") \
1008 \
1009 product(intx, MinPassesBeforeFlush, 10, DIAGNOSTIC, \
1010 "Minimum number of sweeper passes before an nmethod " \
1011 "can be flushed") \
1012 range(0, max_intx) \
1013 \
1014 develop(bool, StressCodeBuffers, false, \
1015 "Exercise code buffer expansion and other rare state changes") \
1016 \
1017 product(bool, DebugNonSafepoints, trueInDebug, DIAGNOSTIC, \
1018 "Generate extra debugging information for non-safepoints in " \
1019 "nmethods") \
1020 \
1021 product(bool, PrintVMOptions, false, \
1022 "Print flags that appeared on the command line") \
1023 \
1024 product(bool, IgnoreUnrecognizedVMOptions, false, \
1025 "Ignore unrecognized VM options") \
1026 \
1027 product(bool, PrintCommandLineFlags, false, \
1028 "Print flags specified on command line or set by ergonomics") \
1029 \
1030 product(bool, PrintFlagsInitial, false, \
1031 "Print all VM flags before argument processing and exit VM") \
1032 \
1033 product(bool, PrintFlagsFinal, false, \
1034 "Print all VM flags after argument and ergonomic processing") \
1035 \
1036 notproduct(bool, PrintFlagsWithComments, false, \
1037 "Print all VM flags with default values and descriptions and " \
1038 "exit") \
1039 \
1040 product(bool, PrintFlagsRanges, false, \
1041 "Print VM flags and their ranges") \
1042 \
1043 product(bool, SerializeVMOutput, true, DIAGNOSTIC, \
1044 "Use a mutex to serialize output to tty and LogFile") \
1045 \
1046 product(bool, DisplayVMOutput, true, DIAGNOSTIC, \
1047 "Display all VM output on the tty, independently of LogVMOutput") \
1048 \
1049 product(bool, LogVMOutput, false, DIAGNOSTIC, \
1050 "Save VM output to LogFile") \
1051 \
1052 product(ccstr, LogFile, nullptr, DIAGNOSTIC, \
1053 "If LogVMOutput or LogCompilation is on, save VM output to " \
1054 "this file [default: ./hotspot_pid%p.log] (%p replaced with pid)")\
1055 \
1056 product(ccstr, ErrorFile, nullptr, \
1057 "If an error occurs, save the error data to this file " \
1058 "[default: ./hs_err_pid%p.log] (%p replaced with pid)") \
1059 \
1060 product(bool, ExtensiveErrorReports, \
1061 PRODUCT_ONLY(false) NOT_PRODUCT(true), \
1062 "Error reports are more extensive.") \
1063 \
1064 product(bool, DisplayVMOutputToStderr, false, \
1065 "If DisplayVMOutput is true, display all VM output to stderr") \
1066 \
1067 product(bool, DisplayVMOutputToStdout, false, \
1068 "If DisplayVMOutput is true, display all VM output to stdout") \
1069 \
1070 product(bool, ErrorFileToStderr, false, \
1071 "If true, error data is printed to stderr instead of a file") \
1072 \
1073 product(bool, ErrorFileToStdout, false, \
1074 "If true, error data is printed to stdout instead of a file") \
1075 \
1076 develop(bool, UseHeavyMonitors, false, \
1077 "(Deprecated) Use heavyweight instead of lightweight Java " \
1078 "monitors") \
1079 \
1080 develop(bool, VerifyHeavyMonitors, false, \
1081 "Checks that no stack locking happens when using " \
1082 "+UseHeavyMonitors") \
1083 \
1084 product(bool, PrintStringTableStatistics, false, \
1085 "print statistics about the StringTable and SymbolTable") \
1086 \
1087 product(bool, VerifyStringTableAtExit, false, DIAGNOSTIC, \
1088 "verify StringTable contents at exit") \
1089 \
1090 notproduct(bool, PrintSymbolTableSizeHistogram, false, \
1091 "print histogram of the symbol table") \
1092 \
1093 product(ccstr, AbortVMOnException, nullptr, DIAGNOSTIC, \
1094 "Call fatal if this exception is thrown. Example: " \
1095 "java -XX:AbortVMOnException=java.lang.NullPointerException Foo") \
1096 \
1097 product(ccstr, AbortVMOnExceptionMessage, nullptr, DIAGNOSTIC, \
1098 "Call fatal if the exception pointed by AbortVMOnException " \
1099 "has this message") \
1100 \
1101 develop(bool, DebugVtables, false, \
1102 "add debugging code to vtable dispatch") \
1103 \
1104 product(bool, RangeCheckElimination, true, \
1105 "Eliminate range checks") \
1106 \
1107 develop_pd(bool, UncommonNullCast, \
1108 "track occurrences of null in casts; adjust compiler tactics") \
1109 \
1110 develop(bool, TypeProfileCasts, true, \
1111 "treat casts like calls for purposes of type profiling") \
1112 \
1113 develop(bool, TraceLivenessGen, false, \
1114 "Trace the generation of liveness analysis information") \
1115 \
1116 notproduct(bool, TraceLivenessQuery, false, \
1117 "Trace queries of liveness analysis information") \
1118 \
1119 notproduct(bool, CollectIndexSetStatistics, false, \
1120 "Collect information about IndexSets") \
1121 \
1122 develop(intx, FastAllocateSizeLimit, 128*K, \
1123 /* Note: This value is zero mod 1<<13 for a cheap sparc set. */ \
1124 "Inline allocations larger than this in doublewords must go slow")\
1125 \
1126 product_pd(bool, CompactStrings, \
1127 "Enable Strings to use single byte chars in backing store") \
1128 \
1129 product_pd(uint, TypeProfileLevel, \
1130 "=XYZ, with Z: Type profiling of arguments at call; " \
1131 "Y: Type profiling of return value at call; " \
1132 "X: Type profiling of parameters to methods; " \
1133 "X, Y and Z in 0=off ; 1=jsr292 only; 2=all methods") \
1134 constraint(TypeProfileLevelConstraintFunc, AfterErgo) \
1135 \
1136 product(int, TypeProfileArgsLimit, 2, \
1137 "max number of call arguments to consider for type profiling") \
1138 range(0, 16) \
1139 \
1140 product(int, TypeProfileParmsLimit, 2, \
1141 "max number of incoming parameters to consider for type profiling"\
1142 ", -1 for all") \
1143 range(-1, 64) \
1144 \
1145 /* statistics */ \
1146 develop(bool, CountCompiledCalls, false, \
1147 "Count method invocations") \
1148 \
1149 notproduct(bool, ICMissHistogram, false, \
1150 "Produce histogram of IC misses") \
1151 \
1152 /* interpreter */ \
1153 product_pd(bool, RewriteBytecodes, \
1154 "Allow rewriting of bytecodes (bytecodes are not immutable)") \
1155 \
1156 product_pd(bool, RewriteFrequentPairs, \
1157 "Rewrite frequently used bytecode pairs into a single bytecode") \
1158 \
1159 product(bool, PrintInterpreter, false, DIAGNOSTIC, \
1160 "Print the generated interpreter code") \
1161 \
1162 product(bool, UseInterpreter, true, \
1163 "Use interpreter for non-compiled methods") \
1164 \
1165 develop(bool, UseFastSignatureHandlers, true, \
1166 "Use fast signature handlers for native calls") \
1167 \
1168 product(bool, UseLoopCounter, true, \
1169 "Increment invocation counter on backward branch") \
1170 \
1171 product_pd(bool, UseOnStackReplacement, \
1172 "Use on stack replacement, calls runtime if invoc. counter " \
1173 "overflows in loop") \
1174 \
1175 notproduct(bool, TraceOnStackReplacement, false, \
1176 "Trace on stack replacement") \
1177 \
1178 product_pd(bool, PreferInterpreterNativeStubs, \
1179 "Use always interpreter stubs for native methods invoked via " \
1180 "interpreter") \
1181 \
1182 develop(bool, CountBytecodes, false, \
1183 "Count number of bytecodes executed") \
1184 \
1185 develop(bool, PrintBytecodeHistogram, false, \
1186 "Print histogram of the executed bytecodes") \
1187 \
1188 develop(bool, PrintBytecodePairHistogram, false, \
1189 "Print histogram of the executed bytecode pairs") \
1190 \
1191 product(bool, PrintSignatureHandlers, false, DIAGNOSTIC, \
1192 "Print code generated for native method signature handlers") \
1193 \
1194 develop(bool, VerifyOops, false, \
1195 "Do plausibility checks for oops") \
1196 \
1197 develop(bool, CheckUnhandledOops, false, \
1198 "Check for unhandled oops in VM code") \
1199 \
1200 develop(bool, VerifyJNIFields, trueInDebug, \
1201 "Verify jfieldIDs for instance fields") \
1202 \
1203 develop(bool, VerifyFPU, false, \
1204 "Verify FPU state (check for NaN's, etc.)") \
1205 \
1206 develop(bool, VerifyActivationFrameSize, false, \
1207 "Verify that activation frame didn't become smaller than its " \
1208 "minimal size") \
1209 \
1210 develop(bool, TraceFrequencyInlining, false, \
1211 "Trace frequency based inlining") \
1212 \
1213 develop_pd(bool, InlineIntrinsics, \
1214 "Use intrinsics in Interpreter that can be statically resolved") \
1215 \
1216 product_pd(bool, ProfileInterpreter, \
1217 "Profile at the bytecode level during interpretation") \
1218 \
1219 develop_pd(bool, ProfileTraps, \
1220 "Profile deoptimization traps at the bytecode level") \
1221 \
1222 product(intx, ProfileMaturityPercentage, 20, \
1223 "number of method invocations/branches (expressed as % of " \
1224 "CompileThreshold) before using the method's profile") \
1225 range(0, 100) \
1226 \
1227 product(bool, PrintMethodData, false, DIAGNOSTIC, \
1228 "Print the results of +ProfileInterpreter at end of run") \
1229 \
1230 develop(bool, VerifyDataPointer, trueInDebug, \
1231 "Verify the method data pointer during interpreter profiling") \
1232 \
1233 notproduct(bool, CrashGCForDumpingJavaThread, false, \
1234 "Manually make GC thread crash then dump java stack trace; " \
1235 "Test only") \
1236 \
1237 /* compilation */ \
1238 product(bool, UseCompiler, true, \
1239 "Use Just-In-Time compilation") \
1240 \
1241 product(bool, UseCounterDecay, true, \
1242 "Adjust recompilation counters") \
1243 \
1244 develop(intx, CounterHalfLifeTime, 30, \
1245 "Half-life time of invocation counters (in seconds)") \
1246 \
1247 develop(intx, CounterDecayMinIntervalLength, 500, \
1248 "The minimum interval (in milliseconds) between invocation of " \
1249 "CounterDecay") \
1250 \
1251 product(bool, AlwaysCompileLoopMethods, false, \
1252 "When using recompilation, never interpret methods " \
1253 "containing loops") \
1254 \
1255 product(intx, AllocatePrefetchStyle, 1, \
1256 "0 = no prefetch, " \
1257 "1 = generate prefetch instructions for each allocation, " \
1258 "2 = use TLAB watermark to gate allocation prefetch, " \
1259 "3 = generate one prefetch instruction per cache line") \
1260 range(0, 3) \
1261 \
1262 product(intx, AllocatePrefetchDistance, -1, \
1263 "Distance to prefetch ahead of allocation pointer. " \
1264 "-1: use system-specific value (automatically determined") \
1265 range(-1, 512) \
1266 \
1267 product(intx, AllocatePrefetchLines, 3, \
1268 "Number of lines to prefetch ahead of array allocation pointer") \
1269 range(1, 64) \
1270 \
1271 product(intx, AllocateInstancePrefetchLines, 1, \
1272 "Number of lines to prefetch ahead of instance allocation " \
1273 "pointer") \
1274 range(1, 64) \
1275 \
1276 product(intx, AllocatePrefetchStepSize, 16, \
1277 "Step size in bytes of sequential prefetch instructions") \
1278 range(1, 512) \
1279 constraint(AllocatePrefetchStepSizeConstraintFunc,AfterMemoryInit)\
1280 \
1281 product(intx, AllocatePrefetchInstr, 0, \
1282 "Select instruction to prefetch ahead of allocation pointer") \
1283 constraint(AllocatePrefetchInstrConstraintFunc, AfterMemoryInit) \
1284 \
1285 /* deoptimization */ \
1286 product(bool, TraceDeoptimization, false, DIAGNOSTIC, \
1287 "Trace deoptimization") \
1288 \
1289 develop(bool, PrintDeoptimizationDetails, false, \
1290 "Print more information about deoptimization") \
1291 \
1292 develop(bool, DebugDeoptimization, false, \
1293 "Tracing various information while debugging deoptimization") \
1294 \
1295 product(double, SelfDestructTimer, 0.0, \
1296 "Will cause VM to terminate after a given time " \
1297 "(in fractional minutes) " \
1298 "(0.0 means off)") \
1299 range(0.0, (double)max_intx) \
1300 \
1301 product(int, MaxJavaStackTraceDepth, 1024, \
1302 "The maximum number of lines in the stack trace for Java " \
1303 "exceptions (0 means all)") \
1304 range(0, max_jint/2) \
1305 \
1306 /* notice: the max range value here is max_jint, not max_intx */ \
1307 /* because of overflow issue */ \
1308 product(intx, GuaranteedSafepointInterval, 1000, DIAGNOSTIC, \
1309 "Guarantee a safepoint (at least) every so many milliseconds " \
1310 "(0 means none)") \
1311 range(0, max_jint) \
1312 \
1313 product(double, SafepointTimeoutDelay, 10000, \
1314 "Delay in milliseconds for option SafepointTimeout; " \
1315 "supports sub-millisecond resolution with fractional values.") \
1316 range(0, max_jlongDouble LP64_ONLY(/MICROUNITS)) \
1317 \
1318 product(bool, UseSystemMemoryBarrier, false, \
1319 "Try to enable system memory barrier if supported by OS") \
1320 \
1321 product(intx, NmethodSweepActivity, 4, \
1322 "Removes cold nmethods from code cache if > 0. Higher values " \
1323 "result in more aggressive sweeping") \
1324 range(0, 2000) \
1325 \
1326 develop(intx, MallocCatchPtr, -1, \
1327 "Hit breakpoint when mallocing/freeing this pointer") \
1328 \
1329 develop(intx, StackPrintLimit, 100, \
1330 "number of stack frames to print in VM-level stack dump") \
1331 \
1332 product(int, ErrorLogPrintCodeLimit, 3, DIAGNOSTIC, \
1333 "max number of compiled code units to print in error log") \
1334 range(0, VMError::max_error_log_print_code) \
1335 \
1336 notproduct(intx, MaxElementPrintSize, 256, \
1337 "maximum number of elements to print") \
1338 \
1339 notproduct(intx, MaxSubklassPrintSize, 4, \
1340 "maximum number of subklasses to print when printing klass") \
1341 \
1342 develop(intx, MaxForceInlineLevel, 100, \
1343 "maximum number of nested calls that are forced for inlining " \
1344 "(using CompileCommand or marked w/ @ForceInline)") \
1345 range(0, max_jint) \
1346 \
1347 develop(intx, MethodHistogramCutoff, 100, \
1348 "The cutoff value for method invocation histogram (+CountCalls)") \
1349 \
1350 develop(intx, DontYieldALotInterval, 10, \
1351 "Interval between which yields will be dropped (milliseconds)") \
1352 \
1353 notproduct(intx, DeoptimizeALotInterval, 5, \
1354 "Number of exits until DeoptimizeALot kicks in") \
1355 \
1356 notproduct(intx, ZombieALotInterval, 5, \
1357 "Number of exits until ZombieALot kicks in") \
1358 \
1359 product(ccstr, MallocLimit, nullptr, DIAGNOSTIC, \
1360 "Limit malloc allocation size from VM. Reaching a limit will " \
1361 "trigger an action (see flag). This feature requires " \
1362 "NativeMemoryTracking=summary or NativeMemoryTracking=detail." \
1363 "Usage:" \
1364 "\"-XX:MallocLimit=<size>[:<flag>]\" sets a total limit." \
1365 "\"-XX:MallocLimit=<category>:<size>[:<flag>][,<category>:<size>[:<flag>] ...]\"" \
1366 "sets one or more category-specific limits." \
1367 "<flag> defines the action upon reaching the limit:" \
1368 "\"fatal\": end VM with a fatal error at the allocation site" \
1369 "\"oom\" : will mimic a native OOM" \
1370 "If <flag> is omitted, \"fatal\" is the default." \
1371 "Examples:\n" \
1372 "-XX:MallocLimit=2g" \
1373 "-XX:MallocLimit=2g:oom" \
1374 "-XX:MallocLimit=compiler:200m:oom,code:100m") \
1375 \
1376 product(intx, TypeProfileWidth, 2, \
1377 "Number of receiver types to record in call/cast profile") \
1378 range(0, 8) \
1379 \
1380 develop(intx, BciProfileWidth, 2, \
1381 "Number of return bci's to record in ret profile") \
1382 \
1383 product(intx, PerMethodRecompilationCutoff, 400, \
1384 "After recompiling N times, stay in the interpreter (-1=>'Inf')") \
1385 range(-1, max_intx) \
1386 \
1387 product(intx, PerBytecodeRecompilationCutoff, 200, \
1388 "Per-BCI limit on repeated recompilation (-1=>'Inf')") \
1389 range(-1, max_intx) \
1390 \
1391 product(intx, PerMethodTrapLimit, 100, \
1392 "Limit on traps (of one kind) in a method (includes inlines)") \
1393 range(0, max_jint) \
1394 \
1395 product(intx, PerMethodSpecTrapLimit, 5000, EXPERIMENTAL, \
1396 "Limit on speculative traps (of one kind) in a method " \
1397 "(includes inlines)") \
1398 range(0, max_jint) \
1399 \
1400 product(intx, PerBytecodeTrapLimit, 4, \
1401 "Limit on traps (of one kind) at a particular BCI") \
1402 range(0, max_jint) \
1403 \
1404 product(int, SpecTrapLimitExtraEntries, 3, EXPERIMENTAL, \
1405 "Extra method data trap entries for speculation") \
1406 \
1407 product(double, InlineFrequencyRatio, 0.25, DIAGNOSTIC, \
1408 "Ratio of call site execution to caller method invocation") \
1409 \
1410 product(double, MinInlineFrequencyRatio, 0.0085, DIAGNOSTIC, \
1411 "Minimum ratio of call site execution to caller method" \
1412 "invocation to be considered for inlining") \
1413 \
1414 develop(intx, InlineThrowCount, 50, \
1415 "Force inlining of interpreted methods that throw this often") \
1416 range(0, max_jint) \
1417 \
1418 develop(intx, InlineThrowMaxSize, 200, \
1419 "Force inlining of throwing methods smaller than this") \
1420 range(0, max_jint) \
1421 \
1422 product(size_t, MetaspaceSize, NOT_LP64(16 * M) LP64_ONLY(21 * M), \
1423 "Initial threshold (in bytes) at which a garbage collection " \
1424 "is done to reduce Metaspace usage") \
1425 constraint(MetaspaceSizeConstraintFunc,AfterErgo) \
1426 \
1427 product(size_t, MaxMetaspaceSize, max_uintx, \
1428 "Maximum size of Metaspaces (in bytes)") \
1429 constraint(MaxMetaspaceSizeConstraintFunc,AfterErgo) \
1430 \
1431 product(size_t, CompressedClassSpaceSize, 1*G, \
1432 "Maximum size of class area in Metaspace when compressed " \
1433 "class pointers are used") \
1434 range(1*M, 3*G) \
1435 \
1436 develop(size_t, CompressedClassSpaceBaseAddress, 0, \
1437 "Force the class space to be allocated at this address or " \
1438 "fails VM initialization (requires -Xshare=off.") \
1439 \
1440 product(bool, PrintMetaspaceStatisticsAtExit, false, DIAGNOSTIC, \
1441 "Print metaspace statistics upon VM exit.") \
1442 \
1443 develop(bool, MetaspaceGuardAllocations, false, \
1444 "Metapace allocations are guarded.") \
1445 \
1446 product(uintx, MinHeapFreeRatio, 40, MANAGEABLE, \
1447 "The minimum percentage of heap free after GC to avoid expansion."\
1448 " For most GCs this applies to the old generation. In G1 and" \
1449 " ParallelGC it applies to the whole heap.") \
1450 range(0, 100) \
1451 constraint(MinHeapFreeRatioConstraintFunc,AfterErgo) \
1452 \
1453 product(uintx, MaxHeapFreeRatio, 70, MANAGEABLE, \
1454 "The maximum percentage of heap free after GC to avoid shrinking."\
1455 " For most GCs this applies to the old generation. In G1 and" \
1456 " ParallelGC it applies to the whole heap.") \
1457 range(0, 100) \
1458 constraint(MaxHeapFreeRatioConstraintFunc,AfterErgo) \
1459 \
1460 product(bool, ShrinkHeapInSteps, true, \
1461 "When disabled, informs the GC to shrink the java heap directly" \
1462 " to the target size at the next full GC rather than requiring" \
1463 " smaller steps during multiple full GCs.") \
1464 \
1465 product(intx, SoftRefLRUPolicyMSPerMB, 1000, \
1466 "Number of milliseconds per MB of free space in the heap") \
1467 range(0, max_intx) \
1468 constraint(SoftRefLRUPolicyMSPerMBConstraintFunc,AfterMemoryInit) \
1469 \
1470 product(size_t, MinHeapDeltaBytes, ScaleForWordSize(128*K), \
1471 "The minimum change in heap space due to GC (in bytes)") \
1472 range(0, max_uintx) \
1473 \
1474 product(size_t, MinMetaspaceExpansion, ScaleForWordSize(256*K), \
1475 "The minimum expansion of Metaspace (in bytes)") \
1476 range(0, max_uintx) \
1477 \
1478 product(uintx, MaxMetaspaceFreeRatio, 70, \
1479 "The maximum percentage of Metaspace free after GC to avoid " \
1480 "shrinking") \
1481 range(0, 100) \
1482 constraint(MaxMetaspaceFreeRatioConstraintFunc,AfterErgo) \
1483 \
1484 product(uintx, MinMetaspaceFreeRatio, 40, \
1485 "The minimum percentage of Metaspace free after GC to avoid " \
1486 "expansion") \
1487 range(0, 99) \
1488 constraint(MinMetaspaceFreeRatioConstraintFunc,AfterErgo) \
1489 \
1490 product(size_t, MaxMetaspaceExpansion, ScaleForWordSize(4*M), \
1491 "The maximum expansion of Metaspace without full GC (in bytes)") \
1492 range(0, max_uintx) \
1493 \
1494 /* stack parameters */ \
1495 product_pd(intx, StackYellowPages, \
1496 "Number of yellow zone (recoverable overflows) pages of size " \
1497 "4KB. If pages are bigger yellow zone is aligned up.") \
1498 range(MIN_STACK_YELLOW_PAGES, (DEFAULT_STACK_YELLOW_PAGES+5)) \
1499 \
1500 product_pd(intx, StackRedPages, \
1501 "Number of red zone (unrecoverable overflows) pages of size " \
1502 "4KB. If pages are bigger red zone is aligned up.") \
1503 range(MIN_STACK_RED_PAGES, (DEFAULT_STACK_RED_PAGES+2)) \
1504 \
1505 product_pd(intx, StackReservedPages, \
1506 "Number of reserved zone (reserved to annotated methods) pages" \
1507 " of size 4KB. If pages are bigger reserved zone is aligned up.") \
1508 range(MIN_STACK_RESERVED_PAGES, (DEFAULT_STACK_RESERVED_PAGES+10))\
1509 \
1510 product(bool, RestrictReservedStack, true, \
1511 "Restrict @ReservedStackAccess to trusted classes") \
1512 \
1513 /* greater stack shadow pages can't generate instruction to bang stack */ \
1514 product_pd(intx, StackShadowPages, \
1515 "Number of shadow zone (for overflow checking) pages of size " \
1516 "4KB. If pages are bigger shadow zone is aligned up. " \
1517 "This should exceed the depth of the VM and native call stack.") \
1518 range(MIN_STACK_SHADOW_PAGES, (DEFAULT_STACK_SHADOW_PAGES+30)) \
1519 \
1520 product_pd(intx, ThreadStackSize, \
1521 "Thread Stack Size (in Kbytes)") \
1522 range(0, 1 * M) \
1523 \
1524 product_pd(intx, VMThreadStackSize, \
1525 "Non-Java Thread Stack Size (in Kbytes)") \
1526 range(0, max_intx/(1 * K)) \
1527 \
1528 product_pd(intx, CompilerThreadStackSize, \
1529 "Compiler Thread Stack Size (in Kbytes)") \
1530 range(0, max_intx/(1 * K)) \
1531 \
1532 develop_pd(size_t, JVMInvokeMethodSlack, \
1533 "Stack space (bytes) required for JVM_InvokeMethod to complete") \
1534 \
1535 /* code cache parameters */ \
1536 product_pd(uintx, CodeCacheSegmentSize, EXPERIMENTAL, \
1537 "Code cache segment size (in bytes) - smallest unit of " \
1538 "allocation") \
1539 range(1, 1024) \
1540 constraint(CodeCacheSegmentSizeConstraintFunc, AfterErgo) \
1541 \
1542 product_pd(intx, CodeEntryAlignment, EXPERIMENTAL, \
1543 "Code entry alignment for generated code (in bytes)") \
1544 constraint(CodeEntryAlignmentConstraintFunc, AfterErgo) \
1545 \
1546 product_pd(intx, OptoLoopAlignment, \
1547 "Align inner loops to zero relative to this modulus") \
1548 range(1, 128) \
1549 constraint(OptoLoopAlignmentConstraintFunc, AfterErgo) \
1550 \
1551 product_pd(uintx, InitialCodeCacheSize, \
1552 "Initial code cache size (in bytes)") \
1553 constraint(VMPageSizeConstraintFunc, AtParse) \
1554 \
1555 develop_pd(uintx, CodeCacheMinimumUseSpace, \
1556 "Minimum code cache size (in bytes) required to start VM.") \
1557 range(0, max_uintx) \
1558 \
1559 product(bool, SegmentedCodeCache, false, \
1560 "Use a segmented code cache") \
1561 \
1562 product_pd(uintx, ReservedCodeCacheSize, \
1563 "Reserved code cache size (in bytes) - maximum code cache size") \
1564 constraint(VMPageSizeConstraintFunc, AtParse) \
1565 \
1566 product_pd(uintx, NonProfiledCodeHeapSize, \
1567 "Size of code heap with non-profiled methods (in bytes)") \
1568 range(0, max_uintx) \
1569 \
1570 product_pd(uintx, ProfiledCodeHeapSize, \
1571 "Size of code heap with profiled methods (in bytes)") \
1572 range(0, max_uintx) \
1573 \
1574 product_pd(uintx, NonNMethodCodeHeapSize, \
1575 "Size of code heap with non-nmethods (in bytes)") \
1576 constraint(VMPageSizeConstraintFunc, AtParse) \
1577 \
1578 product_pd(uintx, CodeCacheExpansionSize, \
1579 "Code cache expansion size (in bytes)") \
1580 range(32*K, max_uintx) \
1581 \
1582 product_pd(uintx, CodeCacheMinBlockLength, DIAGNOSTIC, \
1583 "Minimum number of segments in a code cache block") \
1584 range(1, 100) \
1585 \
1586 notproduct(bool, ExitOnFullCodeCache, false, \
1587 "Exit the VM if we fill the code cache") \
1588 \
1589 product(bool, UseCodeCacheFlushing, true, \
1590 "Remove cold/old nmethods from the code cache") \
1591 \
1592 product(double, SweeperThreshold, 15.0, \
1593 "Threshold when a code cache unloading GC is invoked." \
1594 "Value is percentage of ReservedCodeCacheSize.") \
1595 range(0.0, 100.0) \
1596 \
1597 product(uintx, StartAggressiveSweepingAt, 10, \
1598 "Start aggressive sweeping if X[%] of the code cache is free." \
1599 "Segmented code cache: X[%] of the non-profiled heap." \
1600 "Non-segmented code cache: X[%] of the total code cache") \
1601 range(0, 100) \
1602 \
1603 /* interpreter debugging */ \
1604 develop(intx, BinarySwitchThreshold, 5, \
1605 "Minimal number of lookupswitch entries for rewriting to binary " \
1606 "switch") \
1607 \
1608 develop(intx, StopInterpreterAt, 0, \
1609 "Stop interpreter execution at specified bytecode number") \
1610 \
1611 develop(intx, TraceBytecodesAt, 0, \
1612 "Trace bytecodes starting with specified bytecode number") \
1613 \
1614 develop(intx, TraceBytecodesStopAt, 0, \
1615 "Stop bytecode tracing at the specified bytecode number") \
1616 \
1617 /* Priorities */ \
1618 product_pd(bool, UseThreadPriorities, "Use native thread priorities") \
1619 \
1620 product(int, ThreadPriorityPolicy, 0, \
1621 "0 : Normal. "\
1622 " VM chooses priorities that are appropriate for normal "\
1623 " applications. "\
1624 " On Windows applications are allowed to use higher native "\
1625 " priorities. However, with ThreadPriorityPolicy=0, VM will "\
1626 " not use the highest possible native priority, "\
1627 " THREAD_PRIORITY_TIME_CRITICAL, as it may interfere with "\
1628 " system threads. On Linux thread priorities are ignored "\
1629 " because the OS does not support static priority in "\
1630 " SCHED_OTHER scheduling class which is the only choice for "\
1631 " non-root, non-realtime applications. "\
1632 "1 : Aggressive. "\
1633 " Java thread priorities map over to the entire range of "\
1634 " native thread priorities. Higher Java thread priorities map "\
1635 " to higher native thread priorities. This policy should be "\
1636 " used with care, as sometimes it can cause performance "\
1637 " degradation in the application and/or the entire system. On "\
1638 " Linux/BSD/macOS this policy requires root privilege or an "\
1639 " extended capability.") \
1640 range(0, 1) \
1641 \
1642 product(bool, ThreadPriorityVerbose, false, \
1643 "Print priority changes") \
1644 \
1645 product(int, CompilerThreadPriority, -1, \
1646 "The native priority at which compiler threads should run " \
1647 "(-1 means no change)") \
1648 range(min_jint, max_jint) \
1649 \
1650 product(int, VMThreadPriority, -1, \
1651 "The native priority at which the VM thread should run " \
1652 "(-1 means no change)") \
1653 range(-1, 127) \
1654 \
1655 product(int, JavaPriority1_To_OSPriority, -1, \
1656 "Map Java priorities to OS priorities") \
1657 range(-1, 127) \
1658 \
1659 product(int, JavaPriority2_To_OSPriority, -1, \
1660 "Map Java priorities to OS priorities") \
1661 range(-1, 127) \
1662 \
1663 product(int, JavaPriority3_To_OSPriority, -1, \
1664 "Map Java priorities to OS priorities") \
1665 range(-1, 127) \
1666 \
1667 product(int, JavaPriority4_To_OSPriority, -1, \
1668 "Map Java priorities to OS priorities") \
1669 range(-1, 127) \
1670 \
1671 product(int, JavaPriority5_To_OSPriority, -1, \
1672 "Map Java priorities to OS priorities") \
1673 range(-1, 127) \
1674 \
1675 product(int, JavaPriority6_To_OSPriority, -1, \
1676 "Map Java priorities to OS priorities") \
1677 range(-1, 127) \
1678 \
1679 product(int, JavaPriority7_To_OSPriority, -1, \
1680 "Map Java priorities to OS priorities") \
1681 range(-1, 127) \
1682 \
1683 product(int, JavaPriority8_To_OSPriority, -1, \
1684 "Map Java priorities to OS priorities") \
1685 range(-1, 127) \
1686 \
1687 product(int, JavaPriority9_To_OSPriority, -1, \
1688 "Map Java priorities to OS priorities") \
1689 range(-1, 127) \
1690 \
1691 product(int, JavaPriority10_To_OSPriority,-1, \
1692 "Map Java priorities to OS priorities") \
1693 range(-1, 127) \
1694 \
1695 product(bool, UseCriticalJavaThreadPriority, false, EXPERIMENTAL, \
1696 "Java thread priority 10 maps to critical scheduling priority") \
1697 \
1698 product(bool, UseCriticalCompilerThreadPriority, false, EXPERIMENTAL, \
1699 "Compiler thread(s) run at critical scheduling priority") \
1700 \
1701 develop(intx, NewCodeParameter, 0, \
1702 "Testing Only: Create a dedicated integer parameter before " \
1703 "putback") \
1704 \
1705 /* new oopmap storage allocation */ \
1706 develop(intx, MinOopMapAllocation, 8, \
1707 "Minimum number of OopMap entries in an OopMapSet") \
1708 \
1709 /* recompilation */ \
1710 product_pd(intx, CompileThreshold, \
1711 "number of interpreted method invocations before (re-)compiling") \
1712 constraint(CompileThresholdConstraintFunc, AfterErgo) \
1713 \
1714 product_pd(bool, TieredCompilation, \
1715 "Enable tiered compilation") \
1716 \
1717 /* Properties for Java libraries */ \
1718 \
1719 product(uint64_t, MaxDirectMemorySize, 0, \
1720 "Maximum total size of NIO direct-buffer allocations. " \
1721 "Ignored if not explicitly set.") \
1722 range(0, max_jlong) \
1723 \
1724 /* Flags used for temporary code during development */ \
1725 \
1726 product(bool, UseNewCode, false, DIAGNOSTIC, \
1727 "Testing Only: Use the new version while testing") \
1728 \
1729 product(bool, UseNewCode2, false, DIAGNOSTIC, \
1730 "Testing Only: Use the new version while testing") \
1731 \
1732 product(bool, UseNewCode3, false, DIAGNOSTIC, \
1733 "Testing Only: Use the new version while testing") \
1734 \
1735 notproduct(bool, UseDebuggerErgo, false, \
1736 "Debugging Only: Adjust the VM to be more debugger-friendly. " \
1737 "Turns on the other UseDebuggerErgo* flags") \
1738 \
1739 notproduct(bool, UseDebuggerErgo1, false, \
1740 "Debugging Only: Enable workarounds for debugger induced " \
1741 "os::processor_id() >= os::processor_count() problems") \
1742 \
1743 notproduct(bool, UseDebuggerErgo2, false, \
1744 "Debugging Only: Limit the number of spawned JVM threads") \
1745 \
1746 notproduct(bool, EnableJVMTIStackDepthAsserts, true, \
1747 "Enable JVMTI asserts related to stack depth checks") \
1748 \
1749 /* flags for performance data collection */ \
1750 \
1751 product(bool, UsePerfData, true, \
1752 "Flag to disable jvmstat instrumentation for performance testing "\
1753 "and problem isolation purposes") \
1754 \
1755 product(bool, PerfDataSaveToFile, false, \
1756 "Save PerfData memory to hsperfdata_<pid> file on exit") \
1757 \
1758 product(ccstr, PerfDataSaveFile, nullptr, \
1759 "Save PerfData memory to the specified absolute pathname. " \
1760 "The string %p in the file name (if present) " \
1761 "will be replaced by pid") \
1762 \
1763 product(intx, PerfDataSamplingInterval, 50, \
1764 "Data sampling interval (in milliseconds)") \
1765 range(PeriodicTask::min_interval, max_jint) \
1766 constraint(PerfDataSamplingIntervalFunc, AfterErgo) \
1767 \
1768 product(bool, PerfDisableSharedMem, false, \
1769 "Store performance data in standard memory") \
1770 \
1771 product(int, PerfDataMemorySize, 32*K, \
1772 "Size of performance data memory region. Will be rounded " \
1773 "up to a multiple of the native os page size.") \
1774 range(128, 32*64*K) \
1775 \
1776 product(int, PerfMaxStringConstLength, 1024, \
1777 "Maximum PerfStringConstant string length before truncation") \
1778 range(32, 32*K) \
1779 \
1780 product(bool, PerfAllowAtExitRegistration, false, \
1781 "Allow registration of atexit() methods") \
1782 \
1783 product(bool, PerfBypassFileSystemCheck, false, \
1784 "Bypass Win32 file system criteria checks (Windows Only)") \
1785 \
1786 product(int, UnguardOnExecutionViolation, 0, \
1787 "Unguard page and retry on no-execute fault (Win32 only) " \
1788 "0=off, 1=conservative, 2=aggressive") \
1789 range(0, 2) \
1790 \
1791 /* Serviceability Support */ \
1792 \
1793 product(bool, ManagementServer, false, \
1794 "Create JMX Management Server") \
1795 \
1796 product(bool, DisableAttachMechanism, false, \
1797 "Disable mechanism that allows tools to attach to this VM") \
1798 \
1799 product(bool, StartAttachListener, false, \
1800 "Always start Attach Listener at VM startup") \
1801 \
1802 product(bool, EnableDynamicAgentLoading, true, \
1803 "Allow tools to load agents with the attach mechanism") \
1804 \
1805 product(bool, PrintConcurrentLocks, false, MANAGEABLE, \
1806 "Print java.util.concurrent locks in thread dump") \
1807 \
1808 product(bool, PrintMethodHandleStubs, false, DIAGNOSTIC, \
1809 "Print generated stub code for method handles") \
1810 \
1811 product(bool, VerifyMethodHandles, trueInDebug, DIAGNOSTIC, \
1812 "perform extra checks when constructing method handles") \
1813 \
1814 product(bool, ShowHiddenFrames, false, DIAGNOSTIC, \
1815 "show method handle implementation frames (usually hidden)") \
1816 \
1817 product(bool, ShowCarrierFrames, false, DIAGNOSTIC, \
1818 "show virtual threads' carrier frames in exceptions") \
1819 \
1820 product(bool, TrustFinalNonStaticFields, false, EXPERIMENTAL, \
1821 "trust final non-static declarations for constant folding") \
1822 \
1823 product(bool, FoldStableValues, true, DIAGNOSTIC, \
1824 "Optimize loads from stable fields (marked w/ @Stable)") \
1825 \
1826 product(int, UseBootstrapCallInfo, 1, DIAGNOSTIC, \
1827 "0: when resolving InDy or ConDy, force all BSM arguments to be " \
1828 "resolved before the bootstrap method is called; 1: when a BSM " \
1829 "that may accept a BootstrapCallInfo is detected, use that API " \
1830 "to pass BSM arguments, which allows the BSM to delay their " \
1831 "resolution; 2+: stress test the BCI API by calling more BSMs " \
1832 "via that API, instead of with the eagerly-resolved array.") \
1833 \
1834 product(bool, PauseAtStartup, false, DIAGNOSTIC, \
1835 "Causes the VM to pause at startup time and wait for the pause " \
1836 "file to be removed (default: ./vm.paused.<pid>)") \
1837 \
1838 product(ccstr, PauseAtStartupFile, nullptr, DIAGNOSTIC, \
1839 "The file to create and for whose removal to await when pausing " \
1840 "at startup. (default: ./vm.paused.<pid>)") \
1841 \
1842 product(bool, PauseAtExit, false, DIAGNOSTIC, \
1843 "Pause and wait for keypress on exit if a debugger is attached") \
1844 \
1845 product(bool, DTraceMethodProbes, false, \
1846 "Enable dtrace tool probes for method-entry and method-exit") \
1847 \
1848 product(bool, DTraceAllocProbes, false, \
1849 "Enable dtrace tool probes for object allocation") \
1850 \
1851 product(bool, DTraceMonitorProbes, false, \
1852 "Enable dtrace tool probes for monitor events") \
1853 \
1854 product(bool, RelaxAccessControlCheck, false, \
1855 "Relax the access control checks in the verifier") \
1856 \
1857 product(uintx, StringTableSize, defaultStringTableSize, \
1858 "Number of buckets in the interned String table " \
1859 "(will be rounded to nearest higher power of 2)") \
1860 range(minimumStringTableSize, 16777216ul /* 2^24 */) \
1861 \
1862 product(uintx, SymbolTableSize, defaultSymbolTableSize, EXPERIMENTAL, \
1863 "Number of buckets in the JVM internal Symbol table") \
1864 range(minimumSymbolTableSize, 16777216ul /* 2^24 */) \
1865 \
1866 product(bool, UseStringDeduplication, false, \
1867 "Use string deduplication") \
1868 \
1869 product(uint, StringDeduplicationAgeThreshold, 3, \
1870 "A string must reach this age (or be promoted to an old region) " \
1871 "to be considered for deduplication") \
1872 range(1, markWord::max_age) \
1873 \
1874 product(size_t, StringDeduplicationInitialTableSize, 500, EXPERIMENTAL, \
1875 "Approximate initial number of buckets in the table") \
1876 range(1, 1 * G) \
1877 \
1878 product(double, StringDeduplicationGrowTableLoad, 14.0, EXPERIMENTAL, \
1879 "Entries per bucket above which the table should be expanded") \
1880 range(0.1, 1000.0) \
1881 \
1882 product(double, StringDeduplicationShrinkTableLoad, 1.0, EXPERIMENTAL, \
1883 "Entries per bucket below which the table should be shrunk") \
1884 range(0.01, 100.0) \
1885 \
1886 product(double, StringDeduplicationTargetTableLoad, 7.0, EXPERIMENTAL, \
1887 "Desired entries per bucket when resizing the table") \
1888 range(0.01, 1000.0) \
1889 \
1890 product(size_t, StringDeduplicationCleanupDeadMinimum, 100, EXPERIMENTAL, \
1891 "Minimum number of dead table entries for cleaning the table") \
1892 \
1893 product(int, StringDeduplicationCleanupDeadPercent, 5, EXPERIMENTAL, \
1894 "Minimum percentage of dead table entries for cleaning the table") \
1895 range(1, 100) \
1896 \
1897 product(bool, StringDeduplicationResizeALot, false, DIAGNOSTIC, \
1898 "Force more frequent table resizing") \
1899 \
1900 product(uint64_t, StringDeduplicationHashSeed, 0, DIAGNOSTIC, \
1901 "Seed for the table hashing function; 0 requests computed seed") \
1902 \
1903 product(bool, WhiteBoxAPI, false, DIAGNOSTIC, \
1904 "Enable internal testing APIs") \
1905 \
1906 product(size_t, ArrayAllocatorMallocLimit, SIZE_MAX, EXPERIMENTAL, \
1907 "Allocation less than this value will be allocated " \
1908 "using malloc. Larger allocations will use mmap.") \
1909 \
1910 product(bool, AlwaysAtomicAccesses, false, EXPERIMENTAL, \
1911 "Accesses to all variables should always be atomic") \
1912 \
1913 product(bool, UseUnalignedAccesses, false, DIAGNOSTIC, \
1914 "Use unaligned memory accesses in Unsafe") \
1915 \
1916 product_pd(bool, PreserveFramePointer, \
1917 "Use the FP register for holding the frame pointer " \
1918 "and not as a general purpose register.") \
1919 \
1920 product(size_t, AsyncLogBufferSize, 2*M, \
1921 "Memory budget (in bytes) for the buffer of Asynchronous " \
1922 "Logging (-Xlog:async).") \
1923 range(100*K, 50*M) \
1924 \
1925 product(bool, CheckIntrinsics, true, DIAGNOSTIC, \
1926 "When a class C is loaded, check that " \
1927 "(1) all intrinsics defined by the VM for class C are present "\
1928 "in the loaded class file and are marked with the " \
1929 "@IntrinsicCandidate annotation, that " \
1930 "(2) there is an intrinsic registered for all loaded methods " \
1931 "that are annotated with the @IntrinsicCandidate annotation, " \
1932 "and that " \
1933 "(3) no orphan methods exist for class C (i.e., methods for " \
1934 "which the VM declares an intrinsic but that are not declared "\
1935 "in the loaded class C. " \
1936 "Check (3) is available only in debug builds.") \
1937 \
1938 product_pd(intx, InitArrayShortSize, DIAGNOSTIC, \
1939 "Threshold small size (in bytes) for clearing arrays. " \
1940 "Anything this size or smaller may get converted to discrete " \
1941 "scalar stores.") \
1942 range(0, max_intx) \
1943 constraint(InitArrayShortSizeConstraintFunc, AfterErgo) \
1944 \
1945 product(ccstr, AllocateHeapAt, nullptr, \
1946 "Path to the directory where a temporary file will be created " \
1947 "to use as the backing store for Java Heap.") \
1948 \
1949 product_pd(bool, VMContinuations, EXPERIMENTAL, \
1950 "Enable VM continuations support") \
1951 \
1952 develop(bool, LoomDeoptAfterThaw, false, \
1953 "Deopt stack after thaw") \
1954 \
1955 develop(bool, LoomVerifyAfterThaw, false, \
1956 "Verify stack after thaw") \
1957 \
1958 develop(bool, VerifyContinuations, false, \
1959 "Verify continuation consistency") \
1960 \
1961 develop(bool, UseContinuationFastPath, true, \
1962 "Use fast-path frame walking in continuations") \
1963 \
1964 develop(int, VerifyMetaspaceInterval, DEBUG_ONLY(500) NOT_DEBUG(0), \
1965 "Run periodic metaspace verifications (0 - none, " \
1966 "1 - always, >1 every nth interval)") \
1967 \
1968 product(bool, ShowRegistersOnAssert, true, DIAGNOSTIC, \
1969 "On internal errors, include registers in error report.") \
1970 \
1971 product(bool, UseSwitchProfiling, true, DIAGNOSTIC, \
1972 "leverage profiling for table/lookup switch") \
1973 \
1974 develop(bool, TraceMemoryWriteback, false, \
1975 "Trace memory writeback operations") \
1976 \
1977 JFR_ONLY(product(bool, FlightRecorder, false, \
1978 "(Deprecated) Enable Flight Recorder")) \
1979 \
1980 JFR_ONLY(product(ccstr, FlightRecorderOptions, nullptr, \
1981 "Flight Recorder options")) \
1982 \
1983 JFR_ONLY(product(ccstr, StartFlightRecording, nullptr, \
1984 "Start flight recording with options")) \
1985 \
1986 product(bool, UseFastUnorderedTimeStamps, false, EXPERIMENTAL, \
1987 "Use platform unstable time where supported for timestamps only") \
1988 \
1989 product(bool, EnableValhalla, true, \
1990 "Enable experimental Valhalla features") \
1991 \
1992 product(bool, EnablePrimitiveClasses, false, \
1993 "Enable experimental Valhalla primitive classes") \
1994 \
1995 product_pd(bool, InlineTypePassFieldsAsArgs, \
1996 "Pass each inline type field as an argument at calls") \
1997 \
1998 product_pd(bool, InlineTypeReturnedAsFields, \
1999 "Return fields instead of an inline type reference") \
2000 \
2001 develop(bool, StressCallingConvention, false, \
2002 "Stress the scalarized calling convention.") \
2003 \
2004 product(bool, UseArrayMarkWordCheck, NOT_LP64(false) LP64_ONLY(true), \
2005 "Use bits in the mark word to check for flat/null-free arrays") \
2006 \
2007 product(ccstrlist, ForceNonTearable, "", DIAGNOSTIC, \
2008 "List of inline classes which are forced to be atomic " \
2009 "(whitespace and commas separate names, " \
2010 "and leading and trailing stars '*' are wildcards)") \
2011 \
2012 product(bool, UseEmptySlotsInSupers, true, \
2013 "Allow allocating fields in empty slots of super-classes") \
2014 \
2015 product(bool, DeoptimizeNMethodBarriersALot, false, DIAGNOSTIC, \
2016 "Make nmethod barriers deoptimise a lot.") \
2017 \
2018 develop(bool, VerifyCrossModifyFence, \
2019 false AARCH64_ONLY(DEBUG_ONLY(||true)), \
2020 "Mark all threads after a safepoint, and clear on a modify " \
2021 "fence. Add cleanliness checks.") \
2022 \
2023 product(int, LockingMode, LM_LEGACY, EXPERIMENTAL, \
2024 "Select locking mode: " \
2025 "0: monitors only (LM_MONITOR), " \
2026 "1: monitors & legacy stack-locking (LM_LEGACY, default), " \
2027 "2: monitors & new lightweight locking (LM_LIGHTWEIGHT)") \
2028 range(0, 2) \
2029 \
2030 product(uint, TrimNativeHeapInterval, 0, EXPERIMENTAL, \
2031 "Interval, in ms, at which the JVM will trim the native heap if " \
2032 "the platform supports that. Lower values will reclaim memory " \
2033 "more eagerly at the cost of higher overhead. A value of 0 " \
2034 "(default) disables native heap trimming.") \
2035 range(0, UINT_MAX) \
2036
2037 // end of RUNTIME_FLAGS
2038
2039 DECLARE_FLAGS(LP64_RUNTIME_FLAGS)
2040 DECLARE_ARCH_FLAGS(ARCH_FLAGS)
2041 DECLARE_FLAGS(RUNTIME_FLAGS)
2042 DECLARE_FLAGS(RUNTIME_OS_FLAGS)
2043
2044 #endif // SHARE_RUNTIME_GLOBALS_HPP