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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19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
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(size_t, InlineCacheBufferSize, 10*K, EXPERIMENTAL, \
299 "InlineCacheBuffer size") \
300 \
301 product(bool, InlineArrayCopy, true, DIAGNOSTIC, \
302 "Inline arraycopy native that is known to be part of " \
303 "base library DLL") \
304 \
305 product(bool, InlineObjectHash, true, DIAGNOSTIC, \
306 "Inline Object::hashCode() native that is known to be part " \
307 "of base library DLL") \
308 \
309 product(bool, InlineNatives, true, DIAGNOSTIC, \
310 "Inline natives that are known to be part of base library DLL") \
311 \
312 product(bool, InlineMathNatives, true, DIAGNOSTIC, \
313 "Inline SinD, CosD, etc.") \
314 \
315 product(bool, InlineClassNatives, true, DIAGNOSTIC, \
316 "Inline Class.isInstance, etc") \
317 \
318 product(bool, InlineThreadNatives, true, DIAGNOSTIC, \
319 "Inline Thread.currentThread, etc") \
320 \
321 product(bool, InlineUnsafeOps, true, DIAGNOSTIC, \
322 "Inline memory ops (native methods) from Unsafe") \
323 \
324 product(bool, UseAESIntrinsics, false, DIAGNOSTIC, \
325 "Use intrinsics for AES versions of crypto") \
326 \
327 product(bool, UseAESCTRIntrinsics, false, DIAGNOSTIC, \
328 "Use intrinsics for the paralleled version of AES/CTR crypto") \
329 \
330 product(bool, UseChaCha20Intrinsics, false, DIAGNOSTIC, \
331 "Use intrinsics for the vectorized version of ChaCha20") \
332 \
333 product(bool, UseMD5Intrinsics, false, DIAGNOSTIC, \
334 "Use intrinsics for MD5 crypto hash function") \
335 \
336 product(bool, UseSHA1Intrinsics, false, DIAGNOSTIC, \
337 "Use intrinsics for SHA-1 crypto hash function. " \
338 "Requires that UseSHA is enabled.") \
339 \
340 product(bool, UseSHA256Intrinsics, false, DIAGNOSTIC, \
341 "Use intrinsics for SHA-224 and SHA-256 crypto hash functions. " \
342 "Requires that UseSHA is enabled.") \
343 \
344 product(bool, UseSHA512Intrinsics, false, DIAGNOSTIC, \
345 "Use intrinsics for SHA-384 and SHA-512 crypto hash functions. " \
346 "Requires that UseSHA is enabled.") \
347 \
348 product(bool, UseSHA3Intrinsics, false, DIAGNOSTIC, \
349 "Use intrinsics for SHA3 crypto hash function. " \
350 "Requires that UseSHA is enabled.") \
351 \
352 product(bool, UseCRC32Intrinsics, false, DIAGNOSTIC, \
353 "use intrinsics for java.util.zip.CRC32") \
354 \
355 product(bool, UseCRC32CIntrinsics, false, DIAGNOSTIC, \
356 "use intrinsics for java.util.zip.CRC32C") \
357 \
358 product(bool, UseAdler32Intrinsics, false, DIAGNOSTIC, \
359 "use intrinsics for java.util.zip.Adler32") \
360 \
361 product(bool, UseVectorizedMismatchIntrinsic, false, DIAGNOSTIC, \
362 "Enables intrinsification of ArraysSupport.vectorizedMismatch()") \
363 \
364 product(bool, UseVectorizedHashCodeIntrinsic, false, DIAGNOSTIC, \
365 "Enables intrinsification of ArraysSupport.vectorizedHashCode()") \
366 \
367 product(bool, UseCopySignIntrinsic, false, DIAGNOSTIC, \
368 "Enables intrinsification of Math.copySign") \
369 \
370 product(bool, UseSignumIntrinsic, false, DIAGNOSTIC, \
371 "Enables intrinsification of Math.signum") \
372 \
373 product_pd(bool, DelayCompilerStubsGeneration, DIAGNOSTIC, \
374 "Use Compiler thread for compiler's stubs generation") \
375 \
376 product(ccstrlist, DisableIntrinsic, "", DIAGNOSTIC, \
377 "do not expand intrinsics whose (internal) names appear here") \
378 constraint(DisableIntrinsicConstraintFunc,AfterErgo) \
379 \
380 product(ccstrlist, ControlIntrinsic, "", DIAGNOSTIC, \
381 "Control intrinsics using a list of +/- (internal) names, " \
382 "separated by commas") \
383 constraint(ControlIntrinsicConstraintFunc,AfterErgo) \
384 \
385 develop(bool, TraceCallFixup, false, \
386 "Trace all call fixups") \
387 \
388 develop(bool, DeoptimizeALot, false, \
389 "Deoptimize at every exit from the runtime system") \
390 \
391 notproduct(ccstrlist, DeoptimizeOnlyAt, "", \
392 "A comma separated list of bcis to deoptimize at") \
393 \
394 develop(bool, DeoptimizeRandom, false, \
395 "Deoptimize random frames on random exit from the runtime system")\
396 \
397 notproduct(bool, ZombieALot, false, \
398 "Create non-entrant nmethods at exit from the runtime system") \
399 \
400 notproduct(bool, WalkStackALot, false, \
401 "Trace stack (no print) at every exit from the runtime system") \
402 \
403 develop(bool, DeoptimizeObjectsALot, false, \
404 "For testing purposes concurrent threads revert optimizations " \
405 "based on escape analysis at intervals given with " \
406 "DeoptimizeObjectsALotInterval=n. The thread count is given " \
407 "with DeoptimizeObjectsALotThreadCountSingle and " \
408 "DeoptimizeObjectsALotThreadCountAll.") \
409 \
410 develop(uint64_t, DeoptimizeObjectsALotInterval, 5, \
411 "Interval for DeoptimizeObjectsALot.") \
412 range(0, max_jlong) \
413 \
414 develop(int, DeoptimizeObjectsALotThreadCountSingle, 1, \
415 "The number of threads that revert optimizations based on " \
416 "escape analysis for a single thread if DeoptimizeObjectsALot " \
417 "is enabled. The target thread is selected round robin." ) \
418 range(0, max_jint) \
419 \
420 develop(int, DeoptimizeObjectsALotThreadCountAll, 1, \
421 "The number of threads that revert optimizations based on " \
422 "escape analysis for all threads if DeoptimizeObjectsALot " \
423 "is enabled." ) \
424 range(0, max_jint) \
425 \
426 notproduct(bool, VerifyLastFrame, false, \
427 "Verify oops on last frame on entry to VM") \
428 \
429 product(bool, SafepointTimeout, false, \
430 "Time out and warn or fail after SafepointTimeoutDelay " \
431 "milliseconds if failed to reach safepoint") \
432 \
433 product(bool, AbortVMOnSafepointTimeout, false, DIAGNOSTIC, \
434 "Abort upon failure to reach safepoint (see SafepointTimeout)") \
435 \
436 product(uint64_t, AbortVMOnSafepointTimeoutDelay, 0, DIAGNOSTIC, \
437 "Delay in milliseconds for option AbortVMOnSafepointTimeout") \
438 range(0, max_jlong) \
439 \
440 product(bool, AbortVMOnVMOperationTimeout, false, DIAGNOSTIC, \
441 "Abort upon failure to complete VM operation promptly") \
442 \
443 product(intx, AbortVMOnVMOperationTimeoutDelay, 1000, DIAGNOSTIC, \
444 "Delay in milliseconds for option AbortVMOnVMOperationTimeout") \
445 range(0, max_intx) \
446 \
447 product(bool, MaxFDLimit, true, \
448 "Bump the number of file descriptors to maximum (Unix only)") \
449 \
450 product(bool, LogEvents, true, DIAGNOSTIC, \
451 "Enable the various ring buffer event logs") \
452 \
453 product(int, LogEventsBufferEntries, 20, DIAGNOSTIC, \
454 "Number of ring buffer event logs") \
455 range(1, NOT_LP64(1*K) LP64_ONLY(1*M)) \
456 \
457 product(bool, BytecodeVerificationRemote, true, DIAGNOSTIC, \
458 "Enable the Java bytecode verifier for remote classes") \
459 \
460 product(bool, BytecodeVerificationLocal, false, DIAGNOSTIC, \
461 "Enable the Java bytecode verifier for local classes") \
462 \
463 develop(bool, VerifyStackAtCalls, false, \
464 "Verify that the stack pointer is unchanged after calls") \
465 \
466 develop(bool, TraceJavaAssertions, false, \
467 "Trace java language assertions") \
468 \
469 notproduct(bool, VerifyCodeCache, false, \
470 "Verify code cache on memory allocation/deallocation") \
471 \
472 develop(bool, ZapResourceArea, trueInDebug, \
473 "Zap freed resource/arena space") \
474 \
475 notproduct(bool, ZapVMHandleArea, trueInDebug, \
476 "Zap freed VM handle space") \
477 \
478 notproduct(bool, ZapStackSegments, trueInDebug, \
479 "Zap allocated/freed stack segments") \
480 \
481 develop(bool, ZapUnusedHeapArea, trueInDebug, \
482 "Zap unused heap space") \
483 \
484 develop(bool, CheckZapUnusedHeapArea, false, \
485 "Check zapping of unused heap space") \
486 \
487 develop(bool, ZapFillerObjects, trueInDebug, \
488 "Zap filler objects") \
489 \
490 product(bool, ExecutingUnitTests, false, \
491 "Whether the JVM is running unit tests or not") \
492 \
493 develop(uint, ErrorHandlerTest, 0, \
494 "If > 0, provokes an error after VM initialization; the value " \
495 "determines which error to provoke. See controlled_crash() " \
496 "in vmError.cpp.") \
497 range(0, 17) \
498 \
499 develop(uint, TestCrashInErrorHandler, 0, \
500 "If > 0, provokes an error inside VM error handler (a secondary " \
501 "crash). see controlled_crash() in vmError.cpp") \
502 range(0, 17) \
503 \
504 develop(bool, TestSafeFetchInErrorHandler, false , \
505 "If true, tests SafeFetch inside error handler.") \
506 \
507 develop(bool, TestUnresponsiveErrorHandler, false, \
508 "If true, simulates an unresponsive error handler.") \
509 \
510 develop(bool, Verbose, false, \
511 "Print additional debugging information from other modes") \
512 \
513 develop(bool, PrintMiscellaneous, false, \
514 "Print uncategorized debugging information (requires +Verbose)") \
515 \
516 develop(bool, WizardMode, false, \
517 "Print much more debugging information") \
518 \
519 product(bool, ShowMessageBoxOnError, false, \
520 "Keep process alive on VM fatal error") \
521 \
522 product(bool, CreateCoredumpOnCrash, true, \
523 "Create core/mini dump on VM fatal error") \
524 \
525 product(uint64_t, ErrorLogTimeout, 2 * 60, \
526 "Timeout, in seconds, to limit the time spent on writing an " \
527 "error log in case of a crash.") \
528 range(0, (uint64_t)max_jlong/1000) \
529 \
530 product(bool, ErrorLogSecondaryErrorDetails, false, DIAGNOSTIC, \
531 "If enabled, show details on secondary crashes in the error log") \
532 \
533 develop(intx, TraceDwarfLevel, 0, \
534 "Debug levels for the dwarf parser") \
535 range(0, 4) \
536 \
537 product(bool, SuppressFatalErrorMessage, false, \
538 "Report NO fatal error message (avoid deadlock)") \
539 \
540 product(ccstrlist, OnError, "", \
541 "Run user-defined commands on fatal error; see VMError.cpp " \
542 "for examples") \
543 \
544 product(ccstrlist, OnOutOfMemoryError, "", \
545 "Run user-defined commands on first java.lang.OutOfMemoryError " \
546 "thrown from JVM") \
547 \
548 product(bool, HeapDumpBeforeFullGC, false, MANAGEABLE, \
549 "Dump heap to file before any major stop-the-world GC") \
550 \
551 product(bool, HeapDumpAfterFullGC, false, MANAGEABLE, \
552 "Dump heap to file after any major stop-the-world GC") \
553 \
554 product(bool, HeapDumpOnOutOfMemoryError, false, MANAGEABLE, \
555 "Dump heap to file when java.lang.OutOfMemoryError is thrown " \
556 "from JVM") \
557 \
558 product(ccstr, HeapDumpPath, nullptr, MANAGEABLE, \
559 "When HeapDumpOnOutOfMemoryError is on, the path (filename or " \
560 "directory) of the dump file (defaults to java_pid<pid>.hprof " \
561 "in the working directory)") \
562 \
563 product(int, HeapDumpGzipLevel, 0, MANAGEABLE, \
564 "When HeapDumpOnOutOfMemoryError is on, the gzip compression " \
565 "level of the dump file. 0 (the default) disables gzip " \
566 "compression. Otherwise the level must be between 1 and 9.") \
567 range(0, 9) \
568 \
569 product(ccstr, NativeMemoryTracking, DEBUG_ONLY("summary") NOT_DEBUG("off"), \
570 "Native memory tracking options") \
571 \
572 product(bool, PrintNMTStatistics, false, DIAGNOSTIC, \
573 "Print native memory tracking summary data if it is on") \
574 \
575 product(bool, LogCompilation, false, DIAGNOSTIC, \
576 "Log compilation activity in detail to LogFile") \
577 \
578 product(bool, PrintCompilation, false, \
579 "Print compilations") \
580 \
581 product(intx, RepeatCompilation, 0, DIAGNOSTIC, \
582 "Repeat compilation without installing code (number of times)") \
583 range(0, max_jint) \
584 \
585 product(bool, PrintExtendedThreadInfo, false, \
586 "Print more information in thread dump") \
587 \
588 product(intx, ScavengeRootsInCode, 2, DIAGNOSTIC, \
589 "0: do not allow scavengable oops in the code cache; " \
590 "1: allow scavenging from the code cache; " \
591 "2: emit as many constants as the compiler can see") \
592 range(0, 2) \
593 \
594 product(bool, AlwaysRestoreFPU, false, \
595 "Restore the FPU control word after every JNI call (expensive)") \
596 \
597 product(bool, PrintCompilation2, false, DIAGNOSTIC, \
598 "Print additional statistics per compilation") \
599 \
600 product(bool, PrintAdapterHandlers, false, DIAGNOSTIC, \
601 "Print code generated for i2c/c2i adapters") \
602 \
603 product(bool, VerifyAdapterCalls, trueInDebug, DIAGNOSTIC, \
604 "Verify that i2c/c2i adapters are called properly") \
605 \
606 develop(bool, VerifyAdapterSharing, false, \
607 "Verify that the code for shared adapters is the equivalent") \
608 \
609 product(bool, PrintAssembly, false, DIAGNOSTIC, \
610 "Print assembly code (using external disassembler.so)") \
611 \
612 product(ccstr, PrintAssemblyOptions, nullptr, DIAGNOSTIC, \
613 "Print options string passed to disassembler.so") \
614 \
615 notproduct(bool, PrintNMethodStatistics, false, \
616 "Print a summary statistic for the generated nmethods") \
617 \
618 product(bool, PrintNMethods, false, DIAGNOSTIC, \
619 "Print assembly code for nmethods when generated") \
620 \
621 product(bool, PrintNativeNMethods, false, DIAGNOSTIC, \
622 "Print assembly code for native nmethods when generated") \
623 \
624 develop(bool, PrintDebugInfo, false, \
625 "Print debug information for all nmethods when generated") \
626 \
627 develop(bool, PrintRelocations, false, \
628 "Print relocation information for all nmethods when generated") \
629 \
630 develop(bool, PrintDependencies, false, \
631 "Print dependency information for all nmethods when generated") \
632 \
633 develop(bool, PrintExceptionHandlers, false, \
634 "Print exception handler tables for all nmethods when generated") \
635 \
636 develop(bool, StressCompiledExceptionHandlers, false, \
637 "Exercise compiled exception handlers") \
638 \
639 develop(bool, InterceptOSException, false, \
640 "Start debugger when an implicit OS (e.g. null pointer) " \
641 "exception happens") \
642 \
643 product(bool, PrintCodeCache, false, \
644 "Print the code cache memory usage when exiting") \
645 \
646 develop(bool, PrintCodeCache2, false, \
647 "Print detailed usage information on the code cache when exiting")\
648 \
649 product(bool, PrintCodeCacheOnCompilation, false, \
650 "Print the code cache memory usage each time a method is " \
651 "compiled") \
652 \
653 product(bool, PrintCodeHeapAnalytics, false, DIAGNOSTIC, \
654 "Print code heap usage statistics on exit and on full condition") \
655 \
656 product(bool, PrintStubCode, false, DIAGNOSTIC, \
657 "Print generated stub code") \
658 \
659 product(bool, StackTraceInThrowable, true, \
660 "Collect backtrace in throwable when exception happens") \
661 \
662 product(bool, OmitStackTraceInFastThrow, true, \
663 "Omit backtraces for some 'hot' exceptions in optimized code") \
664 \
665 product(bool, ShowCodeDetailsInExceptionMessages, true, MANAGEABLE, \
666 "Show exception messages from RuntimeExceptions that contain " \
667 "snippets of the failing code. Disable this to improve privacy.") \
668 \
669 product(bool, PrintWarnings, true, \
670 "Print JVM warnings to output stream") \
671 \
672 product(bool, RegisterFinalizersAtInit, true, \
673 "(Deprecated) Register finalizable objects at end of " \
674 "Object.<init> or after allocation") \
675 \
676 develop(bool, RegisterReferences, true, \
677 "Tell whether the VM should register soft/weak/final/phantom " \
678 "references") \
679 \
680 develop(bool, PrintCodeCacheExtension, false, \
681 "Print extension of code cache") \
682 \
683 develop(bool, UsePrivilegedStack, true, \
684 "Enable the security JVM functions") \
685 \
686 product(bool, ClassUnloading, true, \
687 "Do unloading of classes") \
688 \
689 product(bool, ClassUnloadingWithConcurrentMark, true, \
690 "Do unloading of classes with a concurrent marking cycle") \
691 \
692 notproduct(bool, PrintSystemDictionaryAtExit, false, \
693 "Print the system dictionary at exit") \
694 \
695 notproduct(bool, PrintClassLoaderDataGraphAtExit, false, \
696 "Print the class loader data graph at exit") \
697 \
698 product(bool, AllowParallelDefineClass, false, \
699 "Allow parallel defineClass requests for class loaders " \
700 "registering as parallel capable") \
701 \
702 product_pd(bool, DontYieldALot, \
703 "Throw away obvious excess yield calls") \
704 \
705 product(bool, DisablePrimordialThreadGuardPages, false, EXPERIMENTAL, \
706 "Disable the use of stack guard pages if the JVM is loaded " \
707 "on the primordial process thread") \
708 \
709 product(bool, DoJVMTIVirtualThreadTransitions, true, EXPERIMENTAL, \
710 "Do JVMTI virtual thread mount/unmount transitions " \
711 "(disabling this flag implies no JVMTI events are posted)") \
712 \
713 /* notice: the max range value here is max_jint, not max_intx */ \
714 /* because of overflow issue */ \
715 product(intx, AsyncDeflationInterval, 250, DIAGNOSTIC, \
716 "Async deflate idle monitors every so many milliseconds when " \
717 "MonitorUsedDeflationThreshold is exceeded (0 is off).") \
718 range(0, max_jint) \
719 \
720 /* notice: the max range value here is max_jint, not max_intx */ \
721 /* because of overflow issue */ \
722 product(intx, GuaranteedAsyncDeflationInterval, 60000, DIAGNOSTIC, \
723 "Async deflate idle monitors every so many milliseconds even " \
724 "when MonitorUsedDeflationThreshold is NOT exceeded (0 is off).") \
725 range(0, max_jint) \
726 \
727 product(size_t, AvgMonitorsPerThreadEstimate, 1024, DIAGNOSTIC, \
728 "Used to estimate a variable ceiling based on number of threads " \
729 "for use with MonitorUsedDeflationThreshold (0 is off).") \
730 range(0, max_uintx) \
731 \
732 /* notice: the max range value here is max_jint, not max_intx */ \
733 /* because of overflow issue */ \
734 product(intx, MonitorDeflationMax, 1000000, DIAGNOSTIC, \
735 "The maximum number of monitors to deflate, unlink and delete " \
736 "at one time (minimum is 1024).") \
737 range(1024, max_jint) \
738 \
739 product(intx, MonitorUnlinkBatch, 500, DIAGNOSTIC, \
740 "The maximum number of monitors to unlink in one batch. ") \
741 range(1, max_jint) \
742 \
743 product(int, MonitorUsedDeflationThreshold, 90, DIAGNOSTIC, \
744 "Percentage of used monitors before triggering deflation (0 is " \
745 "off). The check is performed on GuaranteedSafepointInterval, " \
746 "AsyncDeflationInterval or GuaranteedAsyncDeflationInterval, " \
747 "whichever is lower.") \
748 range(0, 100) \
749 \
750 product(uintx, NoAsyncDeflationProgressMax, 3, DIAGNOSTIC, \
751 "Max number of no progress async deflation attempts to tolerate " \
752 "before adjusting the in_use_list_ceiling up (0 is off).") \
753 range(0, max_uintx) \
754 \
755 product(intx, hashCode, 5, EXPERIMENTAL, \
756 "(Unstable) select hashCode generation algorithm") \
757 \
758 product(bool, ReduceSignalUsage, false, \
759 "Reduce the use of OS signals in Java and/or the VM") \
760 \
761 develop(bool, LoadLineNumberTables, true, \
762 "Tell whether the class file parser loads line number tables") \
763 \
764 develop(bool, LoadLocalVariableTables, true, \
765 "Tell whether the class file parser loads local variable tables") \
766 \
767 develop(bool, LoadLocalVariableTypeTables, true, \
768 "Tell whether the class file parser loads local variable type" \
769 "tables") \
770 \
771 product(bool, AllowUserSignalHandlers, false, \
772 "Application will install primary signal handlers for the JVM " \
773 "(Unix only)") \
774 \
775 product(bool, UseSignalChaining, true, \
776 "Use signal-chaining to invoke signal handlers installed " \
777 "by the application (Unix only)") \
778 \
779 product(bool, RestoreMXCSROnJNICalls, false, \
780 "Restore MXCSR when returning from JNI calls") \
781 \
782 product(bool, CheckJNICalls, false, \
783 "Verify all arguments to JNI calls") \
784 \
785 product(bool, UseFastJNIAccessors, true, \
786 "Use optimized versions of Get<Primitive>Field") \
787 \
788 product(intx, MaxJNILocalCapacity, 65536, \
789 "Maximum allowable local JNI handle capacity to " \
790 "EnsureLocalCapacity() and PushLocalFrame(), " \
791 "where <= 0 is unlimited, default: 65536") \
792 range(min_intx, max_intx) \
793 \
794 product(bool, EagerXrunInit, false, \
795 "Eagerly initialize -Xrun libraries; allows startup profiling, " \
796 "but not all -Xrun libraries may support the state of the VM " \
797 "at this time") \
798 \
799 product(bool, PreserveAllAnnotations, false, \
800 "Preserve RuntimeInvisibleAnnotations as well " \
801 "as RuntimeVisibleAnnotations") \
802 \
803 develop(uintx, PreallocatedOutOfMemoryErrorCount, 4, \
804 "Number of OutOfMemoryErrors preallocated with backtrace") \
805 \
806 product(bool, UseXMMForArrayCopy, false, \
807 "Use SSE2 MOVQ instruction for Arraycopy") \
808 \
809 notproduct(bool, PrintFieldLayout, false, \
810 "Print field layout for each class") \
811 \
812 /* Need to limit the extent of the padding to reasonable size. */\
813 /* 8K is well beyond the reasonable HW cache line size, even with */\
814 /* aggressive prefetching, while still leaving the room for segregating */\
815 /* among the distinct pages. */\
816 product(int, ContendedPaddingWidth, 128, \
817 "How many bytes to pad the fields/classes marked @Contended with")\
818 range(0, 8192) \
819 constraint(ContendedPaddingWidthConstraintFunc,AfterErgo) \
820 \
821 product(bool, EnableContended, true, \
822 "Enable @Contended annotation support") \
823 \
824 product(bool, RestrictContended, true, \
825 "Restrict @Contended to trusted classes") \
826 \
827 product(int, DiagnoseSyncOnValueBasedClasses, 0, DIAGNOSTIC, \
828 "Detect and take action upon identifying synchronization on " \
829 "value based classes. Modes: " \
830 "0: off; " \
831 "1: exit with fatal error; " \
832 "2: log message to stdout. Output file can be specified with " \
833 " -Xlog:valuebasedclasses. If JFR is running it will " \
834 " also generate JFR events.") \
835 range(0, 2) \
836 \
837 product(bool, ExitOnOutOfMemoryError, false, \
838 "JVM exits on the first occurrence of an out-of-memory error " \
839 "thrown from JVM") \
840 \
841 product(bool, CrashOnOutOfMemoryError, false, \
842 "JVM aborts, producing an error log and core/mini dump, on the " \
843 "first occurrence of an out-of-memory error thrown from JVM") \
844 \
845 product(intx, UserThreadWaitAttemptsAtExit, 30, \
846 "The number of times to wait for user threads to stop executing " \
847 "native code during JVM exit. Each wait lasts 10 milliseconds. " \
848 "The maximum number of waits is 1000, to wait at most 10 " \
849 "seconds.") \
850 range(0, 1000) \
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, VerifyHeavyMonitors, false, \
1077 "Checks that no stack locking happens when using " \
1078 "-XX:LockingMode=0 (LM_MONITOR)") \
1079 \
1080 product(bool, PrintStringTableStatistics, false, \
1081 "print statistics about the StringTable and SymbolTable") \
1082 \
1083 product(bool, VerifyStringTableAtExit, false, DIAGNOSTIC, \
1084 "verify StringTable contents at exit") \
1085 \
1086 notproduct(bool, PrintSymbolTableSizeHistogram, false, \
1087 "print histogram of the symbol table") \
1088 \
1089 product(ccstr, AbortVMOnException, nullptr, DIAGNOSTIC, \
1090 "Call fatal if this exception is thrown. Example: " \
1091 "java -XX:AbortVMOnException=java.lang.NullPointerException Foo") \
1092 \
1093 product(ccstr, AbortVMOnExceptionMessage, nullptr, DIAGNOSTIC, \
1094 "Call fatal if the exception pointed by AbortVMOnException " \
1095 "has this message") \
1096 \
1097 develop(bool, DebugVtables, false, \
1098 "add debugging code to vtable dispatch") \
1099 \
1100 product(bool, RangeCheckElimination, true, \
1101 "Eliminate range checks") \
1102 \
1103 develop_pd(bool, UncommonNullCast, \
1104 "track occurrences of null in casts; adjust compiler tactics") \
1105 \
1106 develop(bool, TypeProfileCasts, true, \
1107 "treat casts like calls for purposes of type profiling") \
1108 \
1109 develop(bool, TraceLivenessGen, false, \
1110 "Trace the generation of liveness analysis information") \
1111 \
1112 notproduct(bool, TraceLivenessQuery, false, \
1113 "Trace queries of liveness analysis information") \
1114 \
1115 notproduct(bool, CollectIndexSetStatistics, false, \
1116 "Collect information about IndexSets") \
1117 \
1118 develop(int, FastAllocateSizeLimit, 128*K, \
1119 /* Note: This value is zero mod 1<<13 for a cheap sparc set. */ \
1120 "Inline allocations larger than this in doublewords must go slow")\
1121 \
1122 product_pd(bool, CompactStrings, \
1123 "Enable Strings to use single byte chars in backing store") \
1124 \
1125 product_pd(uint, TypeProfileLevel, \
1126 "=XYZ, with Z: Type profiling of arguments at call; " \
1127 "Y: Type profiling of return value at call; " \
1128 "X: Type profiling of parameters to methods; " \
1129 "X, Y and Z in 0=off ; 1=jsr292 only; 2=all methods") \
1130 constraint(TypeProfileLevelConstraintFunc, AfterErgo) \
1131 \
1132 product(int, TypeProfileArgsLimit, 2, \
1133 "max number of call arguments to consider for type profiling") \
1134 range(0, 16) \
1135 \
1136 product(int, TypeProfileParmsLimit, 2, \
1137 "max number of incoming parameters to consider for type profiling"\
1138 ", -1 for all") \
1139 range(-1, 64) \
1140 \
1141 /* statistics */ \
1142 develop(bool, CountCompiledCalls, false, \
1143 "Count method invocations") \
1144 \
1145 notproduct(bool, ICMissHistogram, false, \
1146 "Produce histogram of IC misses") \
1147 \
1148 /* interpreter */ \
1149 product_pd(bool, RewriteBytecodes, \
1150 "Allow rewriting of bytecodes (bytecodes are not immutable)") \
1151 \
1152 product_pd(bool, RewriteFrequentPairs, \
1153 "Rewrite frequently used bytecode pairs into a single bytecode") \
1154 \
1155 product(bool, PrintInterpreter, false, DIAGNOSTIC, \
1156 "Print the generated interpreter code") \
1157 \
1158 product(bool, UseInterpreter, true, \
1159 "Use interpreter for non-compiled methods") \
1160 \
1161 develop(bool, UseFastSignatureHandlers, true, \
1162 "Use fast signature handlers for native calls") \
1163 \
1164 product(bool, UseLoopCounter, true, \
1165 "Increment invocation counter on backward branch") \
1166 \
1167 product_pd(bool, UseOnStackReplacement, \
1168 "Use on stack replacement, calls runtime if invoc. counter " \
1169 "overflows in loop") \
1170 \
1171 notproduct(bool, TraceOnStackReplacement, false, \
1172 "Trace on stack replacement") \
1173 \
1174 product_pd(bool, PreferInterpreterNativeStubs, \
1175 "Use always interpreter stubs for native methods invoked via " \
1176 "interpreter") \
1177 \
1178 develop(bool, CountBytecodes, false, \
1179 "Count number of bytecodes executed") \
1180 \
1181 develop(bool, PrintBytecodeHistogram, false, \
1182 "Print histogram of the executed bytecodes") \
1183 \
1184 develop(bool, PrintBytecodePairHistogram, false, \
1185 "Print histogram of the executed bytecode pairs") \
1186 \
1187 product(bool, PrintSignatureHandlers, false, DIAGNOSTIC, \
1188 "Print code generated for native method signature handlers") \
1189 \
1190 develop(bool, VerifyOops, false, \
1191 "Do plausibility checks for oops") \
1192 \
1193 develop(bool, CheckUnhandledOops, false, \
1194 "Check for unhandled oops in VM code") \
1195 \
1196 develop(bool, VerifyJNIFields, trueInDebug, \
1197 "Verify jfieldIDs for instance fields") \
1198 \
1199 develop(bool, VerifyFPU, false, \
1200 "Verify FPU state (check for NaN's, etc.)") \
1201 \
1202 develop(bool, VerifyActivationFrameSize, false, \
1203 "Verify that activation frame didn't become smaller than its " \
1204 "minimal size") \
1205 \
1206 develop(bool, TraceFrequencyInlining, false, \
1207 "Trace frequency based inlining") \
1208 \
1209 develop_pd(bool, InlineIntrinsics, \
1210 "Use intrinsics in Interpreter that can be statically resolved") \
1211 \
1212 product_pd(bool, ProfileInterpreter, \
1213 "Profile at the bytecode level during interpretation") \
1214 \
1215 develop_pd(bool, ProfileTraps, \
1216 "Profile deoptimization traps at the bytecode level") \
1217 \
1218 product(intx, ProfileMaturityPercentage, 20, \
1219 "number of method invocations/branches (expressed as % of " \
1220 "CompileThreshold) before using the method's profile") \
1221 range(0, 100) \
1222 \
1223 product(bool, PrintMethodData, false, DIAGNOSTIC, \
1224 "Print the results of +ProfileInterpreter at end of run") \
1225 \
1226 develop(bool, VerifyDataPointer, trueInDebug, \
1227 "Verify the method data pointer during interpreter profiling") \
1228 \
1229 notproduct(bool, CrashGCForDumpingJavaThread, false, \
1230 "Manually make GC thread crash then dump java stack trace; " \
1231 "Test only") \
1232 \
1233 /* compilation */ \
1234 product(bool, UseCompiler, true, \
1235 "Use Just-In-Time compilation") \
1236 \
1237 develop(intx, CounterHalfLifeTime, 30, \
1238 "Half-life time of invocation counters (in seconds)") \
1239 \
1240 product(bool, AlwaysCompileLoopMethods, false, \
1241 "When using recompilation, never interpret methods " \
1242 "containing loops") \
1243 \
1244 product(int, AllocatePrefetchStyle, 1, \
1245 "0 = no prefetch, " \
1246 "1 = generate prefetch instructions for each allocation, " \
1247 "2 = use TLAB watermark to gate allocation prefetch, " \
1248 "3 = generate one prefetch instruction per cache line") \
1249 range(0, 3) \
1250 \
1251 product(int, AllocatePrefetchDistance, -1, \
1252 "Distance to prefetch ahead of allocation pointer. " \
1253 "-1: use system-specific value (automatically determined") \
1254 range(-1, 512) \
1255 \
1256 product(int, AllocatePrefetchLines, 3, \
1257 "Number of lines to prefetch ahead of array allocation pointer") \
1258 range(1, 64) \
1259 \
1260 product(int, AllocateInstancePrefetchLines, 1, \
1261 "Number of lines to prefetch ahead of instance allocation " \
1262 "pointer") \
1263 range(1, 64) \
1264 \
1265 product(int, AllocatePrefetchStepSize, 16, \
1266 "Step size in bytes of sequential prefetch instructions") \
1267 range(1, 512) \
1268 constraint(AllocatePrefetchStepSizeConstraintFunc,AfterMemoryInit)\
1269 \
1270 product(intx, AllocatePrefetchInstr, 0, \
1271 "Select instruction to prefetch ahead of allocation pointer") \
1272 constraint(AllocatePrefetchInstrConstraintFunc, AfterMemoryInit) \
1273 \
1274 /* deoptimization */ \
1275 product(bool, TraceDeoptimization, false, DIAGNOSTIC, \
1276 "Trace deoptimization") \
1277 \
1278 develop(bool, PrintDeoptimizationDetails, false, \
1279 "Print more information about deoptimization") \
1280 \
1281 develop(bool, DebugDeoptimization, false, \
1282 "Tracing various information while debugging deoptimization") \
1283 \
1284 product(double, SelfDestructTimer, 0.0, \
1285 "Will cause VM to terminate after a given time " \
1286 "(in fractional minutes) " \
1287 "(0.0 means off)") \
1288 range(0.0, (double)max_intx) \
1289 \
1290 product(int, MaxJavaStackTraceDepth, 1024, \
1291 "The maximum number of lines in the stack trace for Java " \
1292 "exceptions (0 means all)") \
1293 range(0, max_jint/2) \
1294 \
1295 /* notice: the max range value here is max_jint, not max_intx */ \
1296 /* because of overflow issue */ \
1297 product(intx, GuaranteedSafepointInterval, 1000, DIAGNOSTIC, \
1298 "Guarantee a safepoint (at least) every so many milliseconds " \
1299 "(0 means none)") \
1300 range(0, max_jint) \
1301 \
1302 product(double, SafepointTimeoutDelay, 10000, \
1303 "Delay in milliseconds for option SafepointTimeout; " \
1304 "supports sub-millisecond resolution with fractional values.") \
1305 range(0, max_jlongDouble LP64_ONLY(/MICROUNITS)) \
1306 \
1307 product(bool, UseSystemMemoryBarrier, false, \
1308 "Try to enable system memory barrier if supported by OS") \
1309 \
1310 product(intx, NmethodSweepActivity, 4, \
1311 "Removes cold nmethods from code cache if > 0. Higher values " \
1312 "result in more aggressive sweeping") \
1313 range(0, 2000) \
1314 \
1315 develop(intx, MallocCatchPtr, -1, \
1316 "Hit breakpoint when mallocing/freeing this pointer") \
1317 \
1318 develop(int, StackPrintLimit, 100, \
1319 "number of stack frames to print in VM-level stack dump") \
1320 \
1321 product(int, ErrorLogPrintCodeLimit, 3, DIAGNOSTIC, \
1322 "max number of compiled code units to print in error log") \
1323 range(0, VMError::max_error_log_print_code) \
1324 \
1325 notproduct(int, MaxElementPrintSize, 256, \
1326 "maximum number of elements to print") \
1327 \
1328 notproduct(intx, MaxSubklassPrintSize, 4, \
1329 "maximum number of subklasses to print when printing klass") \
1330 \
1331 develop(intx, MaxForceInlineLevel, 100, \
1332 "maximum number of nested calls that are forced for inlining " \
1333 "(using CompileCommand or marked w/ @ForceInline)") \
1334 range(0, max_jint) \
1335 \
1336 develop(intx, MethodHistogramCutoff, 100, \
1337 "The cutoff value for method invocation histogram (+CountCalls)") \
1338 \
1339 develop(intx, DontYieldALotInterval, 10, \
1340 "Interval between which yields will be dropped (milliseconds)") \
1341 \
1342 notproduct(intx, DeoptimizeALotInterval, 5, \
1343 "Number of exits until DeoptimizeALot kicks in") \
1344 \
1345 notproduct(intx, ZombieALotInterval, 5, \
1346 "Number of exits until ZombieALot kicks in") \
1347 \
1348 product(ccstr, MallocLimit, nullptr, DIAGNOSTIC, \
1349 "Limit malloc allocation size from VM. Reaching a limit will " \
1350 "trigger an action (see flag). This feature requires " \
1351 "NativeMemoryTracking=summary or NativeMemoryTracking=detail." \
1352 "Usage:" \
1353 "\"-XX:MallocLimit=<size>[:<flag>]\" sets a total limit." \
1354 "\"-XX:MallocLimit=<category>:<size>[:<flag>][,<category>:<size>[:<flag>] ...]\"" \
1355 "sets one or more category-specific limits." \
1356 "<flag> defines the action upon reaching the limit:" \
1357 "\"fatal\": end VM with a fatal error at the allocation site" \
1358 "\"oom\" : will mimic a native OOM" \
1359 "If <flag> is omitted, \"fatal\" is the default." \
1360 "Examples:\n" \
1361 "-XX:MallocLimit=2g" \
1362 "-XX:MallocLimit=2g:oom" \
1363 "-XX:MallocLimit=compiler:200m:oom,code:100m") \
1364 \
1365 product(intx, TypeProfileWidth, 2, \
1366 "Number of receiver types to record in call/cast profile") \
1367 range(0, 8) \
1368 \
1369 develop(intx, BciProfileWidth, 2, \
1370 "Number of return bci's to record in ret profile") \
1371 \
1372 product(intx, PerMethodRecompilationCutoff, 400, \
1373 "After recompiling N times, stay in the interpreter (-1=>'Inf')") \
1374 range(-1, max_intx) \
1375 \
1376 product(intx, PerBytecodeRecompilationCutoff, 200, \
1377 "Per-BCI limit on repeated recompilation (-1=>'Inf')") \
1378 range(-1, max_intx) \
1379 \
1380 product(intx, PerMethodTrapLimit, 100, \
1381 "Limit on traps (of one kind) in a method (includes inlines)") \
1382 range(0, max_jint) \
1383 \
1384 product(intx, PerMethodSpecTrapLimit, 5000, EXPERIMENTAL, \
1385 "Limit on speculative traps (of one kind) in a method " \
1386 "(includes inlines)") \
1387 range(0, max_jint) \
1388 \
1389 product(intx, PerBytecodeTrapLimit, 4, \
1390 "Limit on traps (of one kind) at a particular BCI") \
1391 range(0, max_jint) \
1392 \
1393 product(int, SpecTrapLimitExtraEntries, 3, EXPERIMENTAL, \
1394 "Extra method data trap entries for speculation") \
1395 \
1396 product(double, InlineFrequencyRatio, 0.25, DIAGNOSTIC, \
1397 "Ratio of call site execution to caller method invocation") \
1398 \
1399 product(double, MinInlineFrequencyRatio, 0.0085, DIAGNOSTIC, \
1400 "Minimum ratio of call site execution to caller method" \
1401 "invocation to be considered for inlining") \
1402 \
1403 develop(intx, InlineThrowCount, 50, \
1404 "Force inlining of interpreted methods that throw this often") \
1405 range(0, max_jint) \
1406 \
1407 develop(intx, InlineThrowMaxSize, 200, \
1408 "Force inlining of throwing methods smaller than this") \
1409 range(0, max_jint) \
1410 \
1411 product(size_t, MetaspaceSize, NOT_LP64(16 * M) LP64_ONLY(21 * M), \
1412 "Initial threshold (in bytes) at which a garbage collection " \
1413 "is done to reduce Metaspace usage") \
1414 constraint(MetaspaceSizeConstraintFunc,AfterErgo) \
1415 \
1416 product(size_t, MaxMetaspaceSize, max_uintx, \
1417 "Maximum size of Metaspaces (in bytes)") \
1418 constraint(MaxMetaspaceSizeConstraintFunc,AfterErgo) \
1419 \
1420 product(size_t, CompressedClassSpaceSize, 1*G, \
1421 "Maximum size of class area in Metaspace when compressed " \
1422 "class pointers are used") \
1423 range(1*M, 3*G) \
1424 \
1425 develop(size_t, CompressedClassSpaceBaseAddress, 0, \
1426 "Force the class space to be allocated at this address or " \
1427 "fails VM initialization (requires -Xshare=off.") \
1428 \
1429 develop(bool, RandomizeClassSpaceLocation, true, \
1430 "Randomize location of class space.") \
1431 \
1432 product(bool, PrintMetaspaceStatisticsAtExit, false, DIAGNOSTIC, \
1433 "Print metaspace statistics upon VM exit.") \
1434 \
1435 develop(bool, MetaspaceGuardAllocations, false, \
1436 "Metapace allocations are guarded.") \
1437 \
1438 product(uintx, MinHeapFreeRatio, 40, MANAGEABLE, \
1439 "The minimum percentage of heap free after GC to avoid expansion."\
1440 " For most GCs this applies to the old generation. In G1 and" \
1441 " ParallelGC it applies to the whole heap.") \
1442 range(0, 100) \
1443 constraint(MinHeapFreeRatioConstraintFunc,AfterErgo) \
1444 \
1445 product(uintx, MaxHeapFreeRatio, 70, MANAGEABLE, \
1446 "The maximum percentage of heap free after GC to avoid shrinking."\
1447 " For most GCs this applies to the old generation. In G1 and" \
1448 " ParallelGC it applies to the whole heap.") \
1449 range(0, 100) \
1450 constraint(MaxHeapFreeRatioConstraintFunc,AfterErgo) \
1451 \
1452 product(bool, ShrinkHeapInSteps, true, \
1453 "When disabled, informs the GC to shrink the java heap directly" \
1454 " to the target size at the next full GC rather than requiring" \
1455 " smaller steps during multiple full GCs.") \
1456 \
1457 product(intx, SoftRefLRUPolicyMSPerMB, 1000, \
1458 "Number of milliseconds per MB of free space in the heap") \
1459 range(0, max_intx) \
1460 constraint(SoftRefLRUPolicyMSPerMBConstraintFunc,AfterMemoryInit) \
1461 \
1462 product(size_t, MinHeapDeltaBytes, ScaleForWordSize(128*K), \
1463 "The minimum change in heap space due to GC (in bytes)") \
1464 range(0, max_uintx) \
1465 \
1466 product(size_t, MinMetaspaceExpansion, ScaleForWordSize(256*K), \
1467 "The minimum expansion of Metaspace (in bytes)") \
1468 range(0, max_uintx) \
1469 \
1470 product(uint, MaxMetaspaceFreeRatio, 70, \
1471 "The maximum percentage of Metaspace free after GC to avoid " \
1472 "shrinking") \
1473 range(0, 100) \
1474 constraint(MaxMetaspaceFreeRatioConstraintFunc,AfterErgo) \
1475 \
1476 product(uint, MinMetaspaceFreeRatio, 40, \
1477 "The minimum percentage of Metaspace free after GC to avoid " \
1478 "expansion") \
1479 range(0, 99) \
1480 constraint(MinMetaspaceFreeRatioConstraintFunc,AfterErgo) \
1481 \
1482 product(size_t, MaxMetaspaceExpansion, ScaleForWordSize(4*M), \
1483 "The maximum expansion of Metaspace without full GC (in bytes)") \
1484 range(0, max_uintx) \
1485 \
1486 /* stack parameters */ \
1487 product_pd(intx, StackYellowPages, \
1488 "Number of yellow zone (recoverable overflows) pages of size " \
1489 "4KB. If pages are bigger yellow zone is aligned up.") \
1490 range(MIN_STACK_YELLOW_PAGES, (DEFAULT_STACK_YELLOW_PAGES+5)) \
1491 \
1492 product_pd(intx, StackRedPages, \
1493 "Number of red zone (unrecoverable overflows) pages of size " \
1494 "4KB. If pages are bigger red zone is aligned up.") \
1495 range(MIN_STACK_RED_PAGES, (DEFAULT_STACK_RED_PAGES+2)) \
1496 \
1497 product_pd(intx, StackReservedPages, \
1498 "Number of reserved zone (reserved to annotated methods) pages" \
1499 " of size 4KB. If pages are bigger reserved zone is aligned up.") \
1500 range(MIN_STACK_RESERVED_PAGES, (DEFAULT_STACK_RESERVED_PAGES+10))\
1501 \
1502 product(bool, RestrictReservedStack, true, \
1503 "Restrict @ReservedStackAccess to trusted classes") \
1504 \
1505 /* greater stack shadow pages can't generate instruction to bang stack */ \
1506 product_pd(intx, StackShadowPages, \
1507 "Number of shadow zone (for overflow checking) pages of size " \
1508 "4KB. If pages are bigger shadow zone is aligned up. " \
1509 "This should exceed the depth of the VM and native call stack.") \
1510 range(MIN_STACK_SHADOW_PAGES, (DEFAULT_STACK_SHADOW_PAGES+30)) \
1511 \
1512 product_pd(intx, ThreadStackSize, \
1513 "Thread Stack Size (in Kbytes)") \
1514 range(0, 1 * M) \
1515 \
1516 product_pd(intx, VMThreadStackSize, \
1517 "Non-Java Thread Stack Size (in Kbytes)") \
1518 range(0, max_intx/(1 * K)) \
1519 \
1520 product_pd(intx, CompilerThreadStackSize, \
1521 "Compiler Thread Stack Size (in Kbytes)") \
1522 range(0, max_intx/(1 * K)) \
1523 \
1524 develop_pd(size_t, JVMInvokeMethodSlack, \
1525 "Stack space (bytes) required for JVM_InvokeMethod to complete") \
1526 \
1527 /* code cache parameters */ \
1528 product_pd(uintx, CodeCacheSegmentSize, EXPERIMENTAL, \
1529 "Code cache segment size (in bytes) - smallest unit of " \
1530 "allocation") \
1531 range(1, 1024) \
1532 constraint(CodeCacheSegmentSizeConstraintFunc, AfterErgo) \
1533 \
1534 product_pd(intx, CodeEntryAlignment, EXPERIMENTAL, \
1535 "Code entry alignment for generated code (in bytes)") \
1536 constraint(CodeEntryAlignmentConstraintFunc, AfterErgo) \
1537 \
1538 product_pd(intx, OptoLoopAlignment, \
1539 "Align inner loops to zero relative to this modulus") \
1540 range(1, 128) \
1541 constraint(OptoLoopAlignmentConstraintFunc, AfterErgo) \
1542 \
1543 product_pd(uintx, InitialCodeCacheSize, \
1544 "Initial code cache size (in bytes)") \
1545 constraint(VMPageSizeConstraintFunc, AtParse) \
1546 \
1547 develop_pd(uintx, CodeCacheMinimumUseSpace, \
1548 "Minimum code cache size (in bytes) required to start VM.") \
1549 range(0, max_uintx) \
1550 \
1551 product(bool, SegmentedCodeCache, false, \
1552 "Use a segmented code cache") \
1553 \
1554 product_pd(uintx, ReservedCodeCacheSize, \
1555 "Reserved code cache size (in bytes) - maximum code cache size") \
1556 constraint(VMPageSizeConstraintFunc, AtParse) \
1557 \
1558 product_pd(uintx, NonProfiledCodeHeapSize, \
1559 "Size of code heap with non-profiled methods (in bytes)") \
1560 range(0, max_uintx) \
1561 \
1562 product_pd(uintx, ProfiledCodeHeapSize, \
1563 "Size of code heap with profiled methods (in bytes)") \
1564 range(0, max_uintx) \
1565 \
1566 product_pd(uintx, NonNMethodCodeHeapSize, \
1567 "Size of code heap with non-nmethods (in bytes)") \
1568 constraint(VMPageSizeConstraintFunc, AtParse) \
1569 \
1570 product_pd(uintx, CodeCacheExpansionSize, \
1571 "Code cache expansion size (in bytes)") \
1572 range(32*K, max_uintx) \
1573 \
1574 product_pd(uintx, CodeCacheMinBlockLength, DIAGNOSTIC, \
1575 "Minimum number of segments in a code cache block") \
1576 range(1, 100) \
1577 \
1578 notproduct(bool, ExitOnFullCodeCache, false, \
1579 "Exit the VM if we fill the code cache") \
1580 \
1581 product(bool, UseCodeCacheFlushing, true, \
1582 "Remove cold/old nmethods from the code cache") \
1583 \
1584 product(double, SweeperThreshold, 15.0, \
1585 "Threshold when a code cache unloading GC is invoked." \
1586 "Value is percentage of ReservedCodeCacheSize.") \
1587 range(0.0, 100.0) \
1588 \
1589 product(uintx, StartAggressiveSweepingAt, 10, \
1590 "Start aggressive sweeping if X[%] of the code cache is free." \
1591 "Segmented code cache: X[%] of the non-profiled heap." \
1592 "Non-segmented code cache: X[%] of the total code cache") \
1593 range(0, 100) \
1594 \
1595 /* interpreter debugging */ \
1596 develop(intx, BinarySwitchThreshold, 5, \
1597 "Minimal number of lookupswitch entries for rewriting to binary " \
1598 "switch") \
1599 \
1600 develop(intx, StopInterpreterAt, 0, \
1601 "Stop interpreter execution at specified bytecode number") \
1602 \
1603 develop(intx, TraceBytecodesAt, 0, \
1604 "Trace bytecodes starting with specified bytecode number") \
1605 \
1606 develop(intx, TraceBytecodesStopAt, 0, \
1607 "Stop bytecode tracing at the specified bytecode number") \
1608 \
1609 /* Priorities */ \
1610 product_pd(bool, UseThreadPriorities, "Use native thread priorities") \
1611 \
1612 product(int, ThreadPriorityPolicy, 0, \
1613 "0 : Normal. "\
1614 " VM chooses priorities that are appropriate for normal "\
1615 " applications. "\
1616 " On Windows applications are allowed to use higher native "\
1617 " priorities. However, with ThreadPriorityPolicy=0, VM will "\
1618 " not use the highest possible native priority, "\
1619 " THREAD_PRIORITY_TIME_CRITICAL, as it may interfere with "\
1620 " system threads. On Linux thread priorities are ignored "\
1621 " because the OS does not support static priority in "\
1622 " SCHED_OTHER scheduling class which is the only choice for "\
1623 " non-root, non-realtime applications. "\
1624 "1 : Aggressive. "\
1625 " Java thread priorities map over to the entire range of "\
1626 " native thread priorities. Higher Java thread priorities map "\
1627 " to higher native thread priorities. This policy should be "\
1628 " used with care, as sometimes it can cause performance "\
1629 " degradation in the application and/or the entire system. On "\
1630 " Linux/BSD/macOS this policy requires root privilege or an "\
1631 " extended capability.") \
1632 range(0, 1) \
1633 \
1634 product(bool, ThreadPriorityVerbose, false, \
1635 "Print priority changes") \
1636 \
1637 product(int, CompilerThreadPriority, -1, \
1638 "The native priority at which compiler threads should run " \
1639 "(-1 means no change)") \
1640 range(min_jint, max_jint) \
1641 \
1642 product(int, VMThreadPriority, -1, \
1643 "The native priority at which the VM thread should run " \
1644 "(-1 means no change)") \
1645 range(-1, 127) \
1646 \
1647 product(int, JavaPriority1_To_OSPriority, -1, \
1648 "Map Java priorities to OS priorities") \
1649 range(-1, 127) \
1650 \
1651 product(int, JavaPriority2_To_OSPriority, -1, \
1652 "Map Java priorities to OS priorities") \
1653 range(-1, 127) \
1654 \
1655 product(int, JavaPriority3_To_OSPriority, -1, \
1656 "Map Java priorities to OS priorities") \
1657 range(-1, 127) \
1658 \
1659 product(int, JavaPriority4_To_OSPriority, -1, \
1660 "Map Java priorities to OS priorities") \
1661 range(-1, 127) \
1662 \
1663 product(int, JavaPriority5_To_OSPriority, -1, \
1664 "Map Java priorities to OS priorities") \
1665 range(-1, 127) \
1666 \
1667 product(int, JavaPriority6_To_OSPriority, -1, \
1668 "Map Java priorities to OS priorities") \
1669 range(-1, 127) \
1670 \
1671 product(int, JavaPriority7_To_OSPriority, -1, \
1672 "Map Java priorities to OS priorities") \
1673 range(-1, 127) \
1674 \
1675 product(int, JavaPriority8_To_OSPriority, -1, \
1676 "Map Java priorities to OS priorities") \
1677 range(-1, 127) \
1678 \
1679 product(int, JavaPriority9_To_OSPriority, -1, \
1680 "Map Java priorities to OS priorities") \
1681 range(-1, 127) \
1682 \
1683 product(int, JavaPriority10_To_OSPriority,-1, \
1684 "Map Java priorities to OS priorities") \
1685 range(-1, 127) \
1686 \
1687 product(bool, UseCriticalJavaThreadPriority, false, EXPERIMENTAL, \
1688 "Java thread priority 10 maps to critical scheduling priority") \
1689 \
1690 product(bool, UseCriticalCompilerThreadPriority, false, EXPERIMENTAL, \
1691 "Compiler thread(s) run at critical scheduling priority") \
1692 \
1693 develop(intx, NewCodeParameter, 0, \
1694 "Testing Only: Create a dedicated integer parameter before " \
1695 "putback") \
1696 \
1697 /* new oopmap storage allocation */ \
1698 develop(intx, MinOopMapAllocation, 8, \
1699 "Minimum number of OopMap entries in an OopMapSet") \
1700 \
1701 /* recompilation */ \
1702 product_pd(intx, CompileThreshold, \
1703 "number of interpreted method invocations before (re-)compiling") \
1704 constraint(CompileThresholdConstraintFunc, AfterErgo) \
1705 \
1706 product_pd(bool, TieredCompilation, \
1707 "Enable tiered compilation") \
1708 \
1709 /* Properties for Java libraries */ \
1710 \
1711 product(uint64_t, MaxDirectMemorySize, 0, \
1712 "Maximum total size of NIO direct-buffer allocations. " \
1713 "Ignored if not explicitly set.") \
1714 range(0, max_jlong) \
1715 \
1716 /* Flags used for temporary code during development */ \
1717 \
1718 product(bool, UseNewCode, false, DIAGNOSTIC, \
1719 "Testing Only: Use the new version while testing") \
1720 \
1721 product(bool, UseNewCode2, false, DIAGNOSTIC, \
1722 "Testing Only: Use the new version while testing") \
1723 \
1724 product(bool, UseNewCode3, false, DIAGNOSTIC, \
1725 "Testing Only: Use the new version while testing") \
1726 \
1727 notproduct(bool, UseDebuggerErgo, false, \
1728 "Debugging Only: Adjust the VM to be more debugger-friendly. " \
1729 "Turns on the other UseDebuggerErgo* flags") \
1730 \
1731 notproduct(bool, UseDebuggerErgo1, false, \
1732 "Debugging Only: Enable workarounds for debugger induced " \
1733 "os::processor_id() >= os::processor_count() problems") \
1734 \
1735 notproduct(bool, UseDebuggerErgo2, false, \
1736 "Debugging Only: Limit the number of spawned JVM threads") \
1737 \
1738 notproduct(bool, EnableJVMTIStackDepthAsserts, true, \
1739 "Enable JVMTI asserts related to stack depth checks") \
1740 \
1741 /* flags for performance data collection */ \
1742 \
1743 product(bool, UsePerfData, true, \
1744 "Flag to disable jvmstat instrumentation for performance testing "\
1745 "and problem isolation purposes") \
1746 \
1747 product(bool, PerfDataSaveToFile, false, \
1748 "Save PerfData memory to hsperfdata_<pid> file on exit") \
1749 \
1750 product(ccstr, PerfDataSaveFile, nullptr, \
1751 "Save PerfData memory to the specified absolute pathname. " \
1752 "The string %p in the file name (if present) " \
1753 "will be replaced by pid") \
1754 \
1755 product(int, PerfDataSamplingInterval, 50, \
1756 "Data sampling interval (in milliseconds)") \
1757 range(PeriodicTask::min_interval, max_jint) \
1758 constraint(PerfDataSamplingIntervalFunc, AfterErgo) \
1759 \
1760 product(bool, PerfDisableSharedMem, false, \
1761 "Store performance data in standard memory") \
1762 \
1763 product(int, PerfDataMemorySize, 32*K, \
1764 "Size of performance data memory region. Will be rounded " \
1765 "up to a multiple of the native os page size.") \
1766 range(128, 32*64*K) \
1767 \
1768 product(int, PerfMaxStringConstLength, 1024, \
1769 "Maximum PerfStringConstant string length before truncation") \
1770 range(32, 32*K) \
1771 \
1772 product(bool, PerfAllowAtExitRegistration, false, \
1773 "Allow registration of atexit() methods") \
1774 \
1775 product(bool, PerfBypassFileSystemCheck, false, \
1776 "Bypass Win32 file system criteria checks (Windows Only)") \
1777 \
1778 product(int, UnguardOnExecutionViolation, 0, \
1779 "Unguard page and retry on no-execute fault (Win32 only) " \
1780 "0=off, 1=conservative, 2=aggressive") \
1781 range(0, 2) \
1782 \
1783 /* Serviceability Support */ \
1784 \
1785 product(bool, ManagementServer, false, \
1786 "Create JMX Management Server") \
1787 \
1788 product(bool, DisableAttachMechanism, false, \
1789 "Disable mechanism that allows tools to attach to this VM") \
1790 \
1791 product(bool, StartAttachListener, false, \
1792 "Always start Attach Listener at VM startup") \
1793 \
1794 product(bool, EnableDynamicAgentLoading, true, \
1795 "Allow tools to load agents with the attach mechanism") \
1796 \
1797 product(bool, PrintConcurrentLocks, false, MANAGEABLE, \
1798 "Print java.util.concurrent locks in thread dump") \
1799 \
1800 product(bool, PrintMethodHandleStubs, false, DIAGNOSTIC, \
1801 "Print generated stub code for method handles") \
1802 \
1803 product(bool, VerifyMethodHandles, trueInDebug, DIAGNOSTIC, \
1804 "perform extra checks when constructing method handles") \
1805 \
1806 product(bool, ShowHiddenFrames, false, DIAGNOSTIC, \
1807 "show method handle implementation frames (usually hidden)") \
1808 \
1809 product(bool, ShowCarrierFrames, false, DIAGNOSTIC, \
1810 "show virtual threads' carrier frames in exceptions") \
1811 \
1812 product(bool, TrustFinalNonStaticFields, false, EXPERIMENTAL, \
1813 "trust final non-static declarations for constant folding") \
1814 \
1815 product(bool, FoldStableValues, true, DIAGNOSTIC, \
1816 "Optimize loads from stable fields (marked w/ @Stable)") \
1817 \
1818 product(int, UseBootstrapCallInfo, 1, DIAGNOSTIC, \
1819 "0: when resolving InDy or ConDy, force all BSM arguments to be " \
1820 "resolved before the bootstrap method is called; 1: when a BSM " \
1821 "that may accept a BootstrapCallInfo is detected, use that API " \
1822 "to pass BSM arguments, which allows the BSM to delay their " \
1823 "resolution; 2+: stress test the BCI API by calling more BSMs " \
1824 "via that API, instead of with the eagerly-resolved array.") \
1825 \
1826 product(bool, PauseAtStartup, false, DIAGNOSTIC, \
1827 "Causes the VM to pause at startup time and wait for the pause " \
1828 "file to be removed (default: ./vm.paused.<pid>)") \
1829 \
1830 product(ccstr, PauseAtStartupFile, nullptr, DIAGNOSTIC, \
1831 "The file to create and for whose removal to await when pausing " \
1832 "at startup. (default: ./vm.paused.<pid>)") \
1833 \
1834 product(bool, PauseAtExit, false, DIAGNOSTIC, \
1835 "Pause and wait for keypress on exit if a debugger is attached") \
1836 \
1837 product(bool, DTraceMethodProbes, false, \
1838 "Enable dtrace tool probes for method-entry and method-exit") \
1839 \
1840 product(bool, DTraceAllocProbes, false, \
1841 "Enable dtrace tool probes for object allocation") \
1842 \
1843 product(bool, DTraceMonitorProbes, false, \
1844 "Enable dtrace tool probes for monitor events") \
1845 \
1846 product(bool, RelaxAccessControlCheck, false, \
1847 "Relax the access control checks in the verifier") \
1848 \
1849 product(uintx, StringTableSize, defaultStringTableSize, \
1850 "Number of buckets in the interned String table " \
1851 "(will be rounded to nearest higher power of 2)") \
1852 range(minimumStringTableSize, 16777216ul /* 2^24 */) \
1853 \
1854 product(uintx, SymbolTableSize, defaultSymbolTableSize, EXPERIMENTAL, \
1855 "Number of buckets in the JVM internal Symbol table") \
1856 range(minimumSymbolTableSize, 16777216ul /* 2^24 */) \
1857 \
1858 product(bool, UseStringDeduplication, false, \
1859 "Use string deduplication") \
1860 \
1861 product(uint, StringDeduplicationAgeThreshold, 3, \
1862 "A string must reach this age (or be promoted to an old region) " \
1863 "to be considered for deduplication") \
1864 range(1, markWord::max_age) \
1865 \
1866 product(size_t, StringDeduplicationInitialTableSize, 500, EXPERIMENTAL, \
1867 "Approximate initial number of buckets in the table") \
1868 range(1, 1 * G) \
1869 \
1870 product(double, StringDeduplicationGrowTableLoad, 14.0, EXPERIMENTAL, \
1871 "Entries per bucket above which the table should be expanded") \
1872 range(0.1, 1000.0) \
1873 \
1874 product(double, StringDeduplicationShrinkTableLoad, 1.0, EXPERIMENTAL, \
1875 "Entries per bucket below which the table should be shrunk") \
1876 range(0.01, 100.0) \
1877 \
1878 product(double, StringDeduplicationTargetTableLoad, 7.0, EXPERIMENTAL, \
1879 "Desired entries per bucket when resizing the table") \
1880 range(0.01, 1000.0) \
1881 \
1882 product(size_t, StringDeduplicationCleanupDeadMinimum, 100, EXPERIMENTAL, \
1883 "Minimum number of dead table entries for cleaning the table") \
1884 \
1885 product(int, StringDeduplicationCleanupDeadPercent, 5, EXPERIMENTAL, \
1886 "Minimum percentage of dead table entries for cleaning the table") \
1887 range(1, 100) \
1888 \
1889 product(bool, StringDeduplicationResizeALot, false, DIAGNOSTIC, \
1890 "Force more frequent table resizing") \
1891 \
1892 product(uint64_t, StringDeduplicationHashSeed, 0, DIAGNOSTIC, \
1893 "Seed for the table hashing function; 0 requests computed seed") \
1894 \
1895 product(bool, WhiteBoxAPI, false, DIAGNOSTIC, \
1896 "Enable internal testing APIs") \
1897 \
1898 product(bool, AlwaysAtomicAccesses, false, EXPERIMENTAL, \
1899 "Accesses to all variables should always be atomic") \
1900 \
1901 product(bool, UseUnalignedAccesses, false, DIAGNOSTIC, \
1902 "Use unaligned memory accesses in Unsafe") \
1903 \
1904 product_pd(bool, PreserveFramePointer, \
1905 "Use the FP register for holding the frame pointer " \
1906 "and not as a general purpose register.") \
1907 \
1908 product(size_t, AsyncLogBufferSize, 2*M, \
1909 "Memory budget (in bytes) for the buffer of Asynchronous " \
1910 "Logging (-Xlog:async).") \
1911 range(100*K, 50*M) \
1912 \
1913 product(bool, CheckIntrinsics, true, DIAGNOSTIC, \
1914 "When a class C is loaded, check that " \
1915 "(1) all intrinsics defined by the VM for class C are present "\
1916 "in the loaded class file and are marked with the " \
1917 "@IntrinsicCandidate annotation, that " \
1918 "(2) there is an intrinsic registered for all loaded methods " \
1919 "that are annotated with the @IntrinsicCandidate annotation, " \
1920 "and that " \
1921 "(3) no orphan methods exist for class C (i.e., methods for " \
1922 "which the VM declares an intrinsic but that are not declared "\
1923 "in the loaded class C. " \
1924 "Check (3) is available only in debug builds.") \
1925 \
1926 product_pd(intx, InitArrayShortSize, DIAGNOSTIC, \
1927 "Threshold small size (in bytes) for clearing arrays. " \
1928 "Anything this size or smaller may get converted to discrete " \
1929 "scalar stores.") \
1930 range(0, max_intx) \
1931 constraint(InitArrayShortSizeConstraintFunc, AfterErgo) \
1932 \
1933 product(ccstr, AllocateHeapAt, nullptr, \
1934 "Path to the directory where a temporary file will be created " \
1935 "to use as the backing store for Java Heap.") \
1936 \
1937 product_pd(bool, VMContinuations, EXPERIMENTAL, \
1938 "Enable VM continuations support") \
1939 \
1940 develop(bool, LoomDeoptAfterThaw, false, \
1941 "Deopt stack after thaw") \
1942 \
1943 develop(bool, LoomVerifyAfterThaw, false, \
1944 "Verify stack after thaw") \
1945 \
1946 develop(bool, VerifyContinuations, true, \
1947 "Verify continuation consistency") \
1948 \
1949 develop(bool, UseContinuationFastPath, true, \
1950 "Use fast-path frame walking in continuations") \
1951 \
1952 develop(int, VerifyMetaspaceInterval, DEBUG_ONLY(500) NOT_DEBUG(0), \
1953 "Run periodic metaspace verifications (0 - none, " \
1954 "1 - always, >1 every nth interval)") \
1955 \
1956 product(bool, ShowRegistersOnAssert, true, DIAGNOSTIC, \
1957 "On internal errors, include registers in error report.") \
1958 \
1959 product(bool, UseSwitchProfiling, true, DIAGNOSTIC, \
1960 "leverage profiling for table/lookup switch") \
1961 \
1962 develop(bool, TraceMemoryWriteback, false, \
1963 "Trace memory writeback operations") \
1964 \
1965 JFR_ONLY(product(bool, FlightRecorder, false, \
1966 "(Deprecated) Enable Flight Recorder")) \
1967 \
1968 JFR_ONLY(product(ccstr, FlightRecorderOptions, nullptr, \
1969 "Flight Recorder options")) \
1970 \
1971 JFR_ONLY(product(ccstr, StartFlightRecording, nullptr, \
1972 "Start flight recording with options")) \
1973 \
1974 product(bool, UseFastUnorderedTimeStamps, false, EXPERIMENTAL, \
1975 "Use platform unstable time where supported for timestamps only") \
1976 \
1977 product(bool, UseEmptySlotsInSupers, true, \
1978 "Allow allocating fields in empty slots of super-classes") \
1979 \
1980 product(bool, DeoptimizeNMethodBarriersALot, false, DIAGNOSTIC, \
1981 "Make nmethod barriers deoptimise a lot.") \
1982 \
1983 develop(bool, VerifyCrossModifyFence, \
1984 false AARCH64_ONLY(DEBUG_ONLY(||true)), \
1985 "Mark all threads after a safepoint, and clear on a modify " \
1986 "fence. Add cleanliness checks.") \
1987 \
1988 product(int, LockingMode, LM_LEGACY, \
1989 "Select locking mode: " \
1990 "0: monitors only (LM_MONITOR), " \
1991 "1: monitors & legacy stack-locking (LM_LEGACY, default), " \
1992 "2: monitors & new lightweight locking (LM_LIGHTWEIGHT)") \
1993 range(0, 2) \
1994 \
1995 product(uint, TrimNativeHeapInterval, 0, EXPERIMENTAL, \
1996 "Interval, in ms, at which the JVM will trim the native heap if " \
1997 "the platform supports that. Lower values will reclaim memory " \
1998 "more eagerly at the cost of higher overhead. A value of 0 " \
1999 "(default) disables native heap trimming.") \
2000 range(0, UINT_MAX) \
2001 \
2002 develop(bool, SimulateFullAddressSpace, false, \
2003 "Simulates a very populated, fragmented address space; no " \
2004 "targeted reservations will succeed.") \
2005 \
2006 product(bool, ProfileExceptionHandlers, true, \
2007 "Profile exception handlers") \
2008
2009 // end of RUNTIME_FLAGS
2010
2011 DECLARE_FLAGS(LP64_RUNTIME_FLAGS)
2012 DECLARE_ARCH_FLAGS(ARCH_FLAGS)
2013 DECLARE_FLAGS(RUNTIME_FLAGS)
2014 DECLARE_FLAGS(RUNTIME_OS_FLAGS)
2015
2016 #endif // SHARE_RUNTIME_GLOBALS_HPP