1 /*
2 * Copyright (c) 1997, 2025, 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.
18 *
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.
22 *
23 */
24
25 #ifndef SHARE_RUNTIME_GLOBALS_HPP
26 #define SHARE_RUNTIME_GLOBALS_HPP
27
28 #include "compiler/compiler_globals_pd.hpp"
29 #include "runtime/globals_shared.hpp"
30 #include "utilities/align.hpp"
31 #include "utilities/globalDefinitions.hpp"
32 #include "utilities/macros.hpp"
33 #include CPU_HEADER(globals)
34 #include OS_HEADER(globals)
35 #include OS_CPU_HEADER(globals)
36
37 // develop flags are settable / visible only during development and are constant in the PRODUCT version
38 // product flags are always settable / visible
39 // develop_pd/product_pd flags are the same as develop/product, except that their default values
40 // are specified in platform-dependent header files.
41
42 // Flags must be declared with the following number of parameters:
43 // non-pd flags:
44 // (type, name, default_value, doc), or
45 // (type, name, default_value, extra_attrs, doc)
46 // pd flags:
47 // (type, name, doc), or
48 // (type, name, extra_attrs, doc)
49
50 // A flag must be declared with one of the following types:
51 // bool, int, uint, intx, uintx, size_t, ccstr, ccstrlist, double, or uint64_t.
52 // The type "ccstr" and "ccstrlist" are an alias for "const char*" and is used
53 // only in this file, because the macrology requires single-token type names.
54
55 // The optional extra_attrs parameter may have one of the following values:
56 // DIAGNOSTIC, EXPERIMENTAL, or MANAGEABLE. Currently extra_attrs can be used
57 // only with product/product_pd flags.
58 //
59 // DIAGNOSTIC options are not meant for VM tuning or for product modes.
60 // They are to be used for VM quality assurance or field diagnosis
61 // of VM bugs. They are hidden so that users will not be encouraged to
62 // try them as if they were VM ordinary execution options. However, they
63 // are available in the product version of the VM. Under instruction
64 // from support engineers, VM customers can turn them on to collect
65 // diagnostic information about VM problems. To use a VM diagnostic
66 // option, you must first specify +UnlockDiagnosticVMOptions.
67 // (This master switch also affects the behavior of -Xprintflags.)
68 //
69 // EXPERIMENTAL flags are in support of features that may not be
70 // an officially supported part of a product, but may be available
71 // for experimenting with. They could, for example, be performance
72 // features that may not have undergone full or rigorous QA, but which may
73 // help performance in some cases and released for experimentation
74 // by the community of users and developers. This flag also allows one to
75 // be able to build a fully supported product that nonetheless also
76 // ships with some unsupported, lightly tested, experimental features.
77 // Refer to the documentation of any products using this code for details
78 // on support and fitness for production.
79 // Like the UnlockDiagnosticVMOptions flag above, there is a corresponding
80 // UnlockExperimentalVMOptions flag, which allows the control and
81 // modification of the experimental flags.
82 //
83 // Nota bene: neither diagnostic nor experimental options should be used casually,
84 // Refer to the documentation of any products using this code for details.
85 //
86 // MANAGEABLE flags are writeable external product flags.
87 // They are dynamically writeable through the JDK management interface
88 // (com.sun.management.HotSpotDiagnosticMXBean API) and also through JConsole.
89 // These flags are external exported interface (see CSR). The list of
90 // manageable flags can be queried programmatically through the management
91 // interface.
92 //
93 // A flag can be made as "manageable" only if
94 // - the flag is defined in a CSR request as an external exported interface.
95 // - the VM implementation supports dynamic setting of the flag.
96 // This implies that the VM must *always* query the flag variable
97 // and not reuse state related to the flag state at any given time.
98 // - you want the flag to be queried programmatically by the customers.
99 //
100
101 //
102 // range is a macro that will expand to min and max arguments for range
103 // checking code if provided - see jvmFlagLimit.hpp
104 //
105 // constraint is a macro that will expand to custom function call
106 // for constraint checking if provided - see jvmFlagLimit.hpp
107
108 // Default and minimum StringTable and SymbolTable size values
109 // Must be powers of 2
110 const size_t defaultStringTableSize = NOT_LP64(1024) LP64_ONLY(65536);
111 const size_t minimumStringTableSize = 128;
112 const size_t defaultSymbolTableSize = 32768; // 2^15
113 const size_t minimumSymbolTableSize = 1024;
114
115 #ifdef _LP64
116 #define LP64_RUNTIME_FLAGS(develop, \
117 develop_pd, \
118 product, \
119 product_pd, \
120 range, \
121 constraint) \
122 \
123 product(bool, UseCompressedOops, false, \
124 "Use 32-bit object references in 64-bit VM. " \
125 "lp64_product means flag is always constant in 32 bit VM") \
126 \
127 product(bool, UseCompressedClassPointers, true, \
128 "(Deprecated) Use 32-bit class pointers in 64-bit VM. " \
129 "lp64_product means flag is always constant in 32 bit VM") \
130 \
131 product(bool, UseCompactObjectHeaders, false, EXPERIMENTAL, \
132 "Use compact 64-bit object headers in 64-bit VM") \
133 \
134 product(int, ObjectAlignmentInBytes, 8, \
135 "Default object alignment in bytes, 8 is minimum") \
136 range(8, 256) \
137 constraint(ObjectAlignmentInBytesConstraintFunc, AtParse)
138
139 #else
140 // !_LP64
141
142 #define LP64_RUNTIME_FLAGS(develop, \
143 develop_pd, \
144 product, \
145 product_pd, \
146 range, \
147 constraint)
148 const bool UseCompressedOops = false;
149 const bool UseCompressedClassPointers = false;
150 const bool UseCompactObjectHeaders = false;
151 const int ObjectAlignmentInBytes = 8;
152
153 #endif // _LP64
154
155 #define RUNTIME_FLAGS(develop, \
156 develop_pd, \
157 product, \
158 product_pd, \
159 range, \
160 constraint) \
161 \
162 develop(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(bool, UseAES, false, \
224 "Control whether AES instructions are used when available") \
225 \
226 product(bool, UseFMA, false, \
227 "Control whether FMA instructions are used when available") \
228 \
229 product(bool, UseSHA, false, \
230 "Control whether SHA instructions are used when available") \
231 \
232 product(bool, UseGHASHIntrinsics, false, DIAGNOSTIC, \
233 "Use intrinsics for GHASH versions of crypto") \
234 \
235 product(bool, UseBASE64Intrinsics, false, \
236 "Use intrinsics for java.util.Base64") \
237 \
238 product(bool, UsePoly1305Intrinsics, false, DIAGNOSTIC, \
239 "Use intrinsics for sun.security.util.math.intpoly") \
240 product(bool, UseIntPolyIntrinsics, false, DIAGNOSTIC, \
241 "Use intrinsics for sun.security.util.math.intpoly.MontgomeryIntegerPolynomialP256") \
242 \
243 product(size_t, LargePageSizeInBytes, 0, \
244 "Maximum large page size used (0 will use the default large " \
245 "page size for the environment as the maximum)") \
246 range(0, max_uintx) \
247 \
248 product(size_t, LargePageHeapSizeThreshold, 128*M, \
249 "Use large pages if maximum heap is at least this big") \
250 range(0, max_uintx) \
251 \
252 product(bool, ForceTimeHighResolution, false, \
253 "Using high time resolution (for Win32 only)") \
254 \
255 develop(bool, TracePcPatching, false, \
256 "Trace usage of frame::patch_pc") \
257 \
258 develop(bool, TraceRelocator, false, \
259 "Trace the bytecode relocator") \
260 \
261 \
262 product(bool, SafepointALot, false, DIAGNOSTIC, \
263 "Generate a lot of safepoints. This works with " \
264 "GuaranteedSafepointInterval") \
265 \
266 product(bool, HandshakeALot, false, DIAGNOSTIC, \
267 "Generate a lot of handshakes. This works with " \
268 "GuaranteedSafepointInterval") \
269 \
270 product_pd(bool, BackgroundCompilation, \
271 "A thread requesting compilation is not blocked during " \
272 "compilation") \
273 \
274 product(bool, MethodFlushing, true, \
275 "Reclamation of compiled methods") \
276 \
277 develop(bool, VerifyStack, false, \
278 "Verify stack of each thread when it is entering a runtime call") \
279 \
280 product(bool, ForceUnreachable, false, DIAGNOSTIC, \
281 "Make all non code cache addresses to be unreachable by " \
282 "forcing use of 64bit literal fixups") \
283 \
284 develop(bool, TraceDerivedPointers, false, \
285 "Trace traversal of derived pointers on stack") \
286 \
287 develop(bool, TraceCodeBlobStacks, false, \
288 "Trace stack-walk of codeblobs") \
289 \
290 develop(bool, PrintRewrites, false, \
291 "Print methods that are being rewritten") \
292 \
293 product(bool, UseInlineCaches, true, \
294 "Use Inline Caches for virtual calls ") \
295 \
296 product(bool, InlineArrayCopy, true, DIAGNOSTIC, \
297 "Inline arraycopy native that is known to be part of " \
298 "base library DLL") \
299 \
300 product(bool, InlineObjectHash, true, DIAGNOSTIC, \
301 "Inline Object::hashCode() native that is known to be part " \
302 "of base library DLL") \
303 \
304 product(bool, InlineNatives, true, DIAGNOSTIC, \
305 "Inline natives that are known to be part of base library DLL") \
306 \
307 product(bool, InlineMathNatives, true, DIAGNOSTIC, \
308 "Inline SinD, CosD, etc.") \
309 \
310 product(bool, InlineClassNatives, true, DIAGNOSTIC, \
311 "Inline Class.isInstance, etc") \
312 \
313 product(bool, InlineThreadNatives, true, DIAGNOSTIC, \
314 "Inline Thread.currentThread, etc") \
315 \
316 product(bool, InlineUnsafeOps, true, DIAGNOSTIC, \
317 "Inline memory ops (native methods) from Unsafe") \
318 \
319 product(bool, UseAESIntrinsics, false, DIAGNOSTIC, \
320 "Use intrinsics for AES versions of crypto") \
321 \
322 product(bool, UseAESCTRIntrinsics, false, DIAGNOSTIC, \
323 "Use intrinsics for the paralleled version of AES/CTR crypto") \
324 \
325 product(bool, UseChaCha20Intrinsics, false, DIAGNOSTIC, \
326 "Use intrinsics for the vectorized version of ChaCha20") \
327 \
328 product(bool, UseKyberIntrinsics, false, DIAGNOSTIC, \
329 "Use intrinsics for the vectorized version of Kyber") \
330 product(bool, UseDilithiumIntrinsics, false, DIAGNOSTIC, \
331 "Use intrinsics for the vectorized version of Dilithium") \
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 develop(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 develop(bool, ZombieALot, false, \
398 "Create non-entrant nmethods at exit from the runtime system") \
399 \
400 develop(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 develop(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 develop(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 develop(bool, ZapVMHandleArea, trueInDebug, \
476 "Zap freed VM handle space") \
477 \
478 develop(bool, ZapStackSegments, trueInDebug, \
479 "Zap allocated/freed stack segments") \
480 \
481 develop(bool, ZapUnusedHeapArea, trueInDebug, \
482 "Zap unused heap space") \
483 \
484 develop(bool, ZapFillerObjects, trueInDebug, \
485 "Zap filler objects") \
486 \
487 develop(bool, ZapTLAB, trueInDebug, \
488 "Zap allocated TLABs") \
489 develop(bool, TestingAsyncLoggingDeathTest, false, \
490 "Recursive logging death test") \
491 develop(bool, TestingAsyncLoggingDeathTestNoCrash, false, \
492 "Recursive logging death test (no crash)") \
493 \
494 product(bool, ExecutingUnitTests, false, \
495 "Whether the JVM is running unit tests or not") \
496 \
497 develop(uint, ErrorHandlerTest, 0, \
498 "If > 0, provokes an error after VM initialization; the value " \
499 "determines which error to provoke. See controlled_crash() " \
500 "in vmError.cpp.") \
501 range(0, 17) \
502 \
503 develop(uint, TestCrashInErrorHandler, 0, \
504 "If > 0, provokes an error inside VM error handler (a secondary " \
505 "crash). see controlled_crash() in vmError.cpp") \
506 range(0, 17) \
507 \
508 develop(bool, TestSafeFetchInErrorHandler, false , \
509 "If true, tests SafeFetch inside error handler.") \
510 \
511 develop(bool, TestUnresponsiveErrorHandler, false, \
512 "If true, simulates an unresponsive error handler.") \
513 \
514 develop(bool, Verbose, false, \
515 "Print additional debugging information from other modes") \
516 \
517 develop(bool, PrintMiscellaneous, false, \
518 "Print uncategorized debugging information (requires +Verbose)") \
519 \
520 develop(bool, WizardMode, false, \
521 "Print much more debugging information") \
522 \
523 product(bool, ShowMessageBoxOnError, false, \
524 "Keep process alive on VM fatal error") \
525 \
526 product(bool, CreateCoredumpOnCrash, true, \
527 "Create core/mini dump on VM fatal error") \
528 \
529 product(uint64_t, ErrorLogTimeout, 2 * 60, \
530 "Timeout, in seconds, to limit the time spent on writing an " \
531 "error log in case of a crash.") \
532 range(0, (uint64_t)max_jlong/1000) \
533 \
534 product(bool, ErrorLogSecondaryErrorDetails, false, DIAGNOSTIC, \
535 "If enabled, show details on secondary crashes in the error log") \
536 \
537 develop(intx, TraceDwarfLevel, 0, \
538 "Debug levels for the dwarf parser") \
539 range(0, 4) \
540 \
541 product(bool, SuppressFatalErrorMessage, false, \
542 "Report NO fatal error message (avoid deadlock)") \
543 \
544 product(ccstrlist, OnError, "", \
545 "Run user-defined commands on fatal error; see VMError.cpp " \
546 "for examples") \
547 \
548 product(ccstrlist, OnOutOfMemoryError, "", \
549 "Run user-defined commands on first java.lang.OutOfMemoryError " \
550 "thrown from JVM") \
551 \
552 product(bool, HeapDumpBeforeFullGC, false, MANAGEABLE, \
553 "Dump heap to file before any major stop-the-world GC " \
554 "(also see FullGCHeapDumpLimit, HeapDumpPath, HeapDumpGzipLevel)")\
555 \
556 product(bool, HeapDumpAfterFullGC, false, MANAGEABLE, \
557 "Dump heap to file after any major stop-the-world GC " \
558 "(also see FullGCHeapDumpLimit, HeapDumpPath, HeapDumpGzipLevel)")\
559 \
560 product(uint, FullGCHeapDumpLimit, 0, MANAGEABLE, \
561 "Limit the number of heap dumps triggered by " \
562 "HeapDumpBeforeFullGC or HeapDumpAfterFullGC " \
563 "(0 means no limit)") \
564 \
565 product(bool, HeapDumpOnOutOfMemoryError, false, MANAGEABLE, \
566 "Dump heap to file when java.lang.OutOfMemoryError is thrown " \
567 "from JVM " \
568 "(also see HeapDumpPath, HeapDumpGzipLevel)") \
569 \
570 product(ccstr, HeapDumpPath, nullptr, MANAGEABLE, \
571 "When HeapDumpOnOutOfMemoryError, HeapDumpBeforeFullGC " \
572 "or HeapDumpAfterFullGC is on, the path (filename or " \
573 "directory) of the dump file (defaults to java_pid<pid>.hprof " \
574 "in the working directory)") \
575 \
576 product(int, HeapDumpGzipLevel, 0, MANAGEABLE, \
577 "When HeapDumpOnOutOfMemoryError, HeapDumpBeforeFullGC " \
578 "or HeapDumpAfterFullGC is on, the gzip compression " \
579 "level of the dump file. 0 (the default) disables gzip " \
580 "compression. Otherwise the level must be between 1 and 9.") \
581 range(0, 9) \
582 \
583 product(ccstr, NativeMemoryTracking, DEBUG_ONLY("summary") NOT_DEBUG("off"), \
584 "Native memory tracking options") \
585 \
586 product(bool, PrintNMTStatistics, false, DIAGNOSTIC, \
587 "Print native memory tracking summary data if it is on") \
588 \
589 product(bool, LogCompilation, false, DIAGNOSTIC, \
590 "Log compilation activity in detail to LogFile") \
591 \
592 product(bool, PrintCompilation, false, \
593 "Print compilations") \
594 \
595 product(intx, RepeatCompilation, 0, DIAGNOSTIC, \
596 "Repeat compilation without installing code (number of times)") \
597 range(0, max_jint) \
598 \
599 product(bool, PrintExtendedThreadInfo, false, \
600 "Print more information in thread dump") \
601 \
602 product(intx, ScavengeRootsInCode, 2, DIAGNOSTIC, \
603 "0: do not allow scavengable oops in the code cache; " \
604 "1: allow scavenging from the code cache; " \
605 "2: emit as many constants as the compiler can see") \
606 range(0, 2) \
607 \
608 product(bool, AlwaysRestoreFPU, false, \
609 "Restore the FPU control word after every JNI call (expensive)") \
610 \
611 product(bool, PrintCompilation2, false, DIAGNOSTIC, \
612 "Print additional statistics per compilation") \
613 \
614 product(bool, PrintAdapterHandlers, false, DIAGNOSTIC, \
615 "Print code generated for i2c/c2i adapters") \
616 \
617 product(bool, VerifyAdapterCalls, trueInDebug, DIAGNOSTIC, \
618 "Verify that i2c/c2i adapters are called properly") \
619 \
620 develop(bool, VerifyAdapterSharing, false, \
621 "Verify that the code for shared adapters is the equivalent") \
622 \
623 product(bool, PrintAssembly, false, DIAGNOSTIC, \
624 "Print assembly code (using external disassembler.so)") \
625 \
626 product(ccstr, PrintAssemblyOptions, nullptr, DIAGNOSTIC, \
627 "Print options string passed to disassembler.so") \
628 \
629 develop(bool, PrintNMethodStatistics, false, \
630 "Print a summary statistic for the generated nmethods") \
631 \
632 product(bool, PrintNMethods, false, DIAGNOSTIC, \
633 "Print assembly code for nmethods when generated") \
634 \
635 product(bool, PrintNativeNMethods, false, DIAGNOSTIC, \
636 "Print assembly code for native nmethods when generated") \
637 \
638 develop(bool, PrintDebugInfo, false, \
639 "Print debug information for all nmethods when generated") \
640 \
641 develop(bool, PrintRelocations, false, \
642 "Print relocation information for all nmethods when generated") \
643 \
644 develop(bool, PrintDependencies, false, \
645 "Print dependency information for all nmethods when generated") \
646 \
647 develop(bool, PrintExceptionHandlers, false, \
648 "Print exception handler tables for all nmethods when generated") \
649 \
650 develop(bool, StressCompiledExceptionHandlers, false, \
651 "Exercise compiled exception handlers") \
652 \
653 develop(bool, InterceptOSException, false, \
654 "Start debugger when an implicit OS (e.g. null pointer) " \
655 "exception happens") \
656 \
657 product(bool, PrintCodeCache, false, \
658 "Print the code cache memory usage when exiting") \
659 \
660 develop(bool, PrintCodeCache2, false, \
661 "Print detailed usage information on the code cache when exiting")\
662 \
663 product(bool, PrintCodeCacheOnCompilation, false, \
664 "Print the code cache memory usage each time a method is " \
665 "compiled") \
666 \
667 product(bool, PrintCodeHeapAnalytics, false, DIAGNOSTIC, \
668 "Print code heap usage statistics on exit and on full condition") \
669 \
670 product(bool, PrintStubCode, false, DIAGNOSTIC, \
671 "Print generated stub code") \
672 \
673 product(bool, StackTraceInThrowable, true, \
674 "Collect backtrace in throwable when exception happens") \
675 \
676 product(bool, OmitStackTraceInFastThrow, true, \
677 "Omit backtraces for some 'hot' exceptions in optimized code") \
678 \
679 product(bool, ShowCodeDetailsInExceptionMessages, true, MANAGEABLE, \
680 "Show exception messages from RuntimeExceptions that contain " \
681 "snippets of the failing code. Disable this to improve privacy.") \
682 \
683 product(bool, PrintWarnings, true, \
684 "Print JVM warnings to output stream") \
685 \
686 develop(bool, RegisterReferences, true, \
687 "Tell whether the VM should register soft/weak/final/phantom " \
688 "references") \
689 \
690 develop(bool, PrintCodeCacheExtension, false, \
691 "Print extension of code cache") \
692 \
693 product(bool, ClassUnloading, true, \
694 "Do unloading of classes") \
695 \
696 product(bool, ClassUnloadingWithConcurrentMark, true, \
697 "Do unloading of classes with a concurrent marking cycle") \
698 \
699 develop(bool, PrintSystemDictionaryAtExit, false, \
700 "Print the system dictionary at exit") \
701 \
702 develop(bool, PrintClassLoaderDataGraphAtExit, false, \
703 "Print the class loader data graph at exit") \
704 \
705 product(bool, AllowParallelDefineClass, false, \
706 "Allow parallel defineClass requests for class loaders " \
707 "registering as parallel capable") \
708 \
709 product(bool, DisablePrimordialThreadGuardPages, false, EXPERIMENTAL, \
710 "Disable the use of stack guard pages if the JVM is loaded " \
711 "on the primordial process thread") \
712 \
713 product(bool, DoJVMTIVirtualThreadTransitions, true, EXPERIMENTAL, \
714 "Do JVMTI virtual thread mount/unmount transitions " \
715 "(disabling this flag implies no JVMTI events are posted)") \
716 \
717 /* notice: the max range value here is max_jint, not max_intx */ \
718 /* because of overflow issue */ \
719 product(intx, AsyncDeflationInterval, 250, DIAGNOSTIC, \
720 "Async deflate idle monitors every so many milliseconds when " \
721 "MonitorUsedDeflationThreshold is exceeded (0 is off).") \
722 range(0, max_jint) \
723 \
724 /* notice: the max range value here is max_jint, not max_intx */ \
725 /* because of overflow issue */ \
726 product(intx, GuaranteedAsyncDeflationInterval, 60000, DIAGNOSTIC, \
727 "Async deflate idle monitors every so many milliseconds even " \
728 "when MonitorUsedDeflationThreshold is NOT exceeded (0 is off).") \
729 range(0, max_jint) \
730 \
731 product(size_t, AvgMonitorsPerThreadEstimate, 1024, DIAGNOSTIC, \
732 "Used to estimate a variable ceiling based on number of threads " \
733 "for use with MonitorUsedDeflationThreshold (0 is off).") \
734 range(0, max_uintx) \
735 \
736 /* notice: the max range value here is max_jint, not max_intx */ \
737 /* because of overflow issue */ \
738 product(intx, MonitorDeflationMax, 1000000, DIAGNOSTIC, \
739 "The maximum number of monitors to deflate, unlink and delete " \
740 "at one time (minimum is 1024).") \
741 range(1024, max_jint) \
742 \
743 product(intx, MonitorUnlinkBatch, 500, DIAGNOSTIC, \
744 "The maximum number of monitors to unlink in one batch. ") \
745 range(1, max_jint) \
746 \
747 product(int, MonitorUsedDeflationThreshold, 90, DIAGNOSTIC, \
748 "Percentage of used monitors before triggering deflation (0 is " \
749 "off). The check is performed on AsyncDeflationInterval or " \
750 "GuaranteedAsyncDeflationInterval, whichever is lower.") \
751 range(0, 100) \
752 \
753 product(uintx, NoAsyncDeflationProgressMax, 3, DIAGNOSTIC, \
754 "Max number of no progress async deflation attempts to tolerate " \
755 "before adjusting the in_use_list_ceiling up (0 is off).") \
756 range(0, max_uintx) \
757 \
758 product(intx, hashCode, 5, EXPERIMENTAL, \
759 "(Unstable) select hashCode generation algorithm") \
760 \
761 product(bool, ReduceSignalUsage, false, \
762 "Reduce the use of OS signals in Java and/or the VM") \
763 \
764 develop(bool, LoadLineNumberTables, true, \
765 "Tell whether the class file parser loads line number tables") \
766 \
767 develop(bool, LoadLocalVariableTables, true, \
768 "Tell whether the class file parser loads local variable tables") \
769 \
770 develop(bool, LoadLocalVariableTypeTables, true, \
771 "Tell whether the class file parser loads local variable type" \
772 "tables") \
773 \
774 product(bool, AllowUserSignalHandlers, false, \
775 "Application will install primary signal handlers for the JVM " \
776 "(Unix only)") \
777 \
778 product(bool, UseSignalChaining, true, \
779 "Use signal-chaining to invoke signal handlers installed " \
780 "by the application (Unix only)") \
781 \
782 product(bool, RestoreMXCSROnJNICalls, false, \
783 "Restore MXCSR when returning from JNI calls") \
784 \
785 product(bool, CheckJNICalls, false, \
786 "Verify all arguments to JNI calls") \
787 \
788 product(bool, UseFastJNIAccessors, true, \
789 "Use optimized versions of Get<Primitive>Field") \
790 \
791 product(intx, MaxJNILocalCapacity, 65536, \
792 "Maximum allowable local JNI handle capacity to " \
793 "EnsureLocalCapacity() and PushLocalFrame(), " \
794 "where <= 0 is unlimited, default: 65536") \
795 range(min_intx, max_intx) \
796 \
797 product(bool, EagerXrunInit, false, \
798 "Eagerly initialize -Xrun libraries; allows startup profiling, " \
799 "but not all -Xrun libraries may support the state of the VM " \
800 "at this time") \
801 \
802 develop(uintx, PreallocatedOutOfMemoryErrorCount, 4, \
803 "Number of OutOfMemoryErrors preallocated with backtrace") \
804 \
805 product(bool, UseXMMForArrayCopy, false, \
806 "Use SSE2 MOVQ instruction for Arraycopy") \
807 \
808 product(bool, PrintFieldLayout, false, DIAGNOSTIC, \
809 "Print field layout for each class") \
810 \
811 product(bool, PrintInlineLayout, false, DIAGNOSTIC, \
812 "Print field layout for each inline type or class with inline fields") \
813 \
814 product(bool, PrintFlatArrayLayout, false, DIAGNOSTIC, \
815 "Print array layout for each inline type array") \
816 \
817 product(bool, UseArrayFlattening, true, \
818 "Allow the VM to flatten arrays") \
819 \
820 product(bool, UseFieldFlattening, true, \
821 "Allow the VM to flatten value fields") \
822 \
823 product(bool, UseNonAtomicValueFlattening, true, \
824 "Allow the JVM to flatten some non-atomic null-free values") \
825 \
826 product(bool, UseNullableValueFlattening, true, \
827 "Allow the JVM to flatten some nullable values") \
828 \
829 product(bool, UseAtomicValueFlattening, true, \
830 "Allow the JVM to flatten some atomic values") \
831 \
832 product(intx, FlatArrayElementMaxOops, 4, \
833 "Max nof embedded object references in an inline type to flatten, <0 no limit") \
834 \
835 /* Need to limit the extent of the padding to reasonable size. */\
836 /* 8K is well beyond the reasonable HW cache line size, even with */\
837 /* aggressive prefetching, while still leaving the room for segregating */\
838 /* among the distinct pages. */\
839 product(int, ContendedPaddingWidth, 128, \
840 "How many bytes to pad the fields/classes marked @Contended with")\
841 range(0, 8192) \
842 constraint(ContendedPaddingWidthConstraintFunc,AfterErgo) \
843 \
844 product(bool, EnableContended, true, \
845 "Enable @Contended annotation support") \
846 \
847 product(bool, RestrictContended, true, \
848 "Restrict @Contended to trusted classes") \
849 \
850 product(int, DiagnoseSyncOnValueBasedClasses, 0, DIAGNOSTIC, \
851 "Detect and take action upon identifying synchronization on " \
852 "value based classes. Modes: " \
853 "0: off; " \
854 "1: exit with fatal error; " \
855 "2: log message to stdout. Output file can be specified with " \
856 " -Xlog:valuebasedclasses. If JFR is running it will " \
857 " also generate JFR events.") \
858 range(0, 2) \
859 \
860 product(bool, ExitOnOutOfMemoryError, false, \
861 "JVM exits on the first occurrence of an out-of-memory error " \
862 "thrown from JVM") \
863 \
864 product(bool, CrashOnOutOfMemoryError, false, \
865 "JVM aborts, producing an error log and core/mini dump, on the " \
866 "first occurrence of an out-of-memory error thrown from JVM") \
867 \
868 product(intx, UserThreadWaitAttemptsAtExit, 30, \
869 "The number of times to wait for user threads to stop executing " \
870 "native code during JVM exit. Each wait lasts 10 milliseconds. " \
871 "The maximum number of waits is 1000, to wait at most 10 " \
872 "seconds.") \
873 range(0, 1000) \
874 \
875 /* tracing */ \
876 \
877 develop(bool, StressRewriter, false, \
878 "Stress linktime bytecode rewriting") \
879 \
880 product(ccstr, TraceJVMTI, nullptr, \
881 "Trace flags for JVMTI functions and events") \
882 \
883 product(bool, StressLdcRewrite, false, DIAGNOSTIC, \
884 "Force ldc -> ldc_w rewrite during RedefineClasses. " \
885 "This option can change an EMCP method into an obsolete method " \
886 "and can affect tests that expect specific methods to be EMCP. " \
887 "This option should be used with caution.") \
888 \
889 product(bool, AllowRedefinitionToAddDeleteMethods, false, \
890 "(Deprecated) Allow redefinition to add and delete private " \
891 "static or final methods for compatibility with old releases") \
892 \
893 develop(bool, TraceBytecodes, false, \
894 "Trace bytecode execution") \
895 \
896 develop(bool, TraceBytecodesTruncated, false, \
897 "Truncate non control-flow bytecode when tracing bytecode") \
898 \
899 develop(bool, VerifyDependencies, trueInDebug, \
900 "Exercise and verify the compilation dependency mechanism") \
901 \
902 develop(bool, TraceNewOopMapGeneration, false, \
903 "Trace OopMapGeneration") \
904 \
905 develop(bool, TraceNewOopMapGenerationDetailed, false, \
906 "Trace OopMapGeneration: print detailed cell states") \
907 \
908 develop(bool, TimeOopMap, false, \
909 "Time calls to GenerateOopMap::compute_map() in sum") \
910 \
911 develop(bool, TimeOopMap2, false, \
912 "Time calls to GenerateOopMap::compute_map() individually") \
913 \
914 develop(bool, TraceOopMapRewrites, false, \
915 "Trace rewriting of methods during oop map generation") \
916 \
917 develop(bool, TraceFinalizerRegistration, false, \
918 "Trace registration of final references") \
919 \
920 product(bool, IgnoreEmptyClassPaths, false, \
921 "Ignore empty path elements in -classpath") \
922 \
923 product(bool, PrintHeapAtSIGBREAK, true, \
924 "Print heap layout in response to SIGBREAK") \
925 \
926 product(bool, PrintClassHistogram, false, MANAGEABLE, \
927 "Print a histogram of class instances") \
928 \
929 product(double, ObjectCountCutOffPercent, 0.5, EXPERIMENTAL, \
930 "The percentage of the used heap that the instances of a class " \
931 "must occupy for the class to generate a trace event") \
932 range(0.0, 100.0) \
933 \
934 /* JVMTI heap profiling */ \
935 \
936 product(bool, VerifyBeforeIteration, false, DIAGNOSTIC, \
937 "Verify memory system before JVMTI iteration") \
938 \
939 /* compiler */ \
940 \
941 /* notice: the max range value here is max_jint, not max_intx */ \
942 /* because of overflow issue */ \
943 product(intx, CICompilerCount, CI_COMPILER_COUNT, \
944 "Number of compiler threads to run") \
945 range(0, max_jint) \
946 constraint(CICompilerCountConstraintFunc, AfterErgo) \
947 \
948 product(bool, UseDynamicNumberOfCompilerThreads, true, \
949 "Dynamically choose the number of parallel compiler threads") \
950 \
951 product(bool, ReduceNumberOfCompilerThreads, true, DIAGNOSTIC, \
952 "Reduce the number of parallel compiler threads when they " \
953 "are not used") \
954 \
955 product(bool, TraceCompilerThreads, false, DIAGNOSTIC, \
956 "Trace creation and removal of compiler threads") \
957 \
958 product(ccstr, LogClassLoadingCauseFor, nullptr, \
959 "Apply -Xlog:class+load+cause* to classes whose fully " \
960 "qualified name contains this string (\"*\" matches " \
961 "any class).") \
962 \
963 develop(bool, InjectCompilerCreationFailure, false, \
964 "Inject thread creation failures for " \
965 "UseDynamicNumberOfCompilerThreads") \
966 \
967 develop(bool, GenerateSynchronizationCode, true, \
968 "generate locking/unlocking code for synchronized methods and " \
969 "monitors") \
970 \
971 product_pd(bool, ImplicitNullChecks, DIAGNOSTIC, \
972 "Generate code for implicit null checks") \
973 \
974 product_pd(bool, TrapBasedNullChecks, \
975 "Generate code for null checks that uses a cmp and trap " \
976 "instruction raising SIGTRAP. This is only used if an access to" \
977 "null (+offset) will not raise a SIGSEGV, i.e.," \
978 "ImplicitNullChecks don't work (PPC64).") \
979 \
980 product(bool, EnableThreadSMRStatistics, trueInDebug, DIAGNOSTIC, \
981 "Enable Thread SMR Statistics") \
982 \
983 product(bool, Inline, true, \
984 "Enable inlining") \
985 \
986 product(bool, ClipInlining, true, \
987 "Clip inlining if aggregate method exceeds DesiredMethodLimit") \
988 \
989 develop(bool, UseCHA, true, \
990 "Enable CHA") \
991 \
992 product(bool, UseTypeProfile, true, \
993 "Check interpreter profile for historically monomorphic calls") \
994 \
995 product(bool, PrintInlining, false, DIAGNOSTIC, \
996 "Print inlining optimizations") \
997 \
998 product(bool, UsePopCountInstruction, false, \
999 "Use population count instruction") \
1000 \
1001 develop(bool, TraceMethodReplacement, false, \
1002 "Print when methods are replaced do to recompilation") \
1003 \
1004 product(intx, MinPassesBeforeFlush, 10, DIAGNOSTIC, \
1005 "Minimum number of sweeper passes before an nmethod " \
1006 "can be flushed") \
1007 range(0, max_intx) \
1008 \
1009 develop(bool, StressCodeBuffers, false, \
1010 "Exercise code buffer expansion and other rare state changes") \
1011 \
1012 product(bool, DebugNonSafepoints, trueInDebug, DIAGNOSTIC, \
1013 "Generate extra debugging information for non-safepoints in " \
1014 "nmethods") \
1015 \
1016 product(bool, PrintVMOptions, false, \
1017 "Print flags that appeared on the command line") \
1018 \
1019 product(bool, IgnoreUnrecognizedVMOptions, false, \
1020 "Ignore unrecognized VM options") \
1021 \
1022 product(bool, PrintCommandLineFlags, false, \
1023 "Print flags specified on command line or set by ergonomics") \
1024 \
1025 product(bool, PrintFlagsInitial, false, \
1026 "Print all VM flags before argument processing and exit VM") \
1027 \
1028 product(bool, PrintFlagsFinal, false, \
1029 "Print all VM flags after argument and ergonomic processing") \
1030 \
1031 develop(bool, PrintFlagsWithComments, false, \
1032 "Print all VM flags with default values and descriptions and " \
1033 "exit") \
1034 \
1035 product(bool, PrintFlagsRanges, false, \
1036 "Print VM flags and their ranges") \
1037 \
1038 product(bool, SerializeVMOutput, true, DIAGNOSTIC, \
1039 "Use a mutex to serialize output to tty and LogFile") \
1040 \
1041 product(bool, DisplayVMOutput, true, DIAGNOSTIC, \
1042 "Display all VM output on the tty, independently of LogVMOutput") \
1043 \
1044 product(bool, LogVMOutput, false, DIAGNOSTIC, \
1045 "Save VM output to LogFile") \
1046 \
1047 product(ccstr, LogFile, nullptr, DIAGNOSTIC, \
1048 "If LogVMOutput or LogCompilation is on, save VM output to " \
1049 "this file [default: ./hotspot_pid%p.log] (%p replaced with pid)")\
1050 \
1051 product(ccstr, ErrorFile, nullptr, \
1052 "If an error occurs, save the error data to this file " \
1053 "[default: ./hs_err_pid%p.log] (%p replaced with pid)") \
1054 \
1055 product(bool, ExtensiveErrorReports, \
1056 PRODUCT_ONLY(false) NOT_PRODUCT(true), \
1057 "Error reports are more extensive.") \
1058 \
1059 product(bool, DisplayVMOutputToStderr, false, \
1060 "If DisplayVMOutput is true, display all VM output to stderr") \
1061 \
1062 product(bool, DisplayVMOutputToStdout, false, \
1063 "If DisplayVMOutput is true, display all VM output to stdout") \
1064 \
1065 product(bool, ErrorFileToStderr, false, \
1066 "If true, error data is printed to stderr instead of a file") \
1067 \
1068 product(bool, ErrorFileToStdout, false, \
1069 "If true, error data is printed to stdout instead of a file") \
1070 \
1071 develop(bool, VerifyHeavyMonitors, false, \
1072 "Checks that no stack locking happens when using " \
1073 "-XX:LockingMode=0 (LM_MONITOR)") \
1074 \
1075 product(bool, PrintStringTableStatistics, false, \
1076 "print statistics about the StringTable and SymbolTable") \
1077 \
1078 product(bool, VerifyStringTableAtExit, false, DIAGNOSTIC, \
1079 "verify StringTable contents at exit") \
1080 \
1081 develop(bool, PrintSymbolTableSizeHistogram, false, \
1082 "print histogram of the symbol table") \
1083 \
1084 product(ccstr, AbortVMOnException, nullptr, DIAGNOSTIC, \
1085 "Call fatal if this exception is thrown. Example: " \
1086 "java -XX:AbortVMOnException=java.lang.NullPointerException Foo") \
1087 \
1088 product(ccstr, AbortVMOnExceptionMessage, nullptr, DIAGNOSTIC, \
1089 "Call fatal if the exception pointed by AbortVMOnException " \
1090 "has this message") \
1091 \
1092 develop(bool, DebugVtables, false, \
1093 "add debugging code to vtable dispatch") \
1094 \
1095 product(bool, RangeCheckElimination, true, \
1096 "Eliminate range checks") \
1097 \
1098 develop_pd(bool, UncommonNullCast, \
1099 "track occurrences of null in casts; adjust compiler tactics") \
1100 \
1101 develop(bool, TypeProfileCasts, true, \
1102 "treat casts like calls for purposes of type profiling") \
1103 \
1104 develop(bool, TraceLivenessGen, false, \
1105 "Trace the generation of liveness analysis information") \
1106 \
1107 develop(bool, TraceLivenessQuery, false, \
1108 "Trace queries of liveness analysis information") \
1109 \
1110 develop(bool, CollectIndexSetStatistics, false, \
1111 "Collect information about IndexSets") \
1112 \
1113 develop(int, FastAllocateSizeLimit, 128*K, \
1114 /* Note: This value is zero mod 1<<13 for a cheap sparc set. */ \
1115 "Inline allocations larger than this in doublewords must go slow")\
1116 \
1117 product_pd(bool, CompactStrings, \
1118 "Enable Strings to use single byte chars in backing store") \
1119 \
1120 product_pd(uint, TypeProfileLevel, \
1121 "=XYZ, with Z: Type profiling of arguments at call; " \
1122 "Y: Type profiling of return value at call; " \
1123 "X: Type profiling of parameters to methods; " \
1124 "X, Y and Z in 0=off ; 1=jsr292 only; 2=all methods") \
1125 constraint(TypeProfileLevelConstraintFunc, AfterErgo) \
1126 \
1127 product(int, TypeProfileArgsLimit, 2, \
1128 "max number of call arguments to consider for type profiling") \
1129 range(0, 16) \
1130 \
1131 product(int, TypeProfileParmsLimit, 2, \
1132 "max number of incoming parameters to consider for type profiling"\
1133 ", -1 for all") \
1134 range(-1, 64) \
1135 \
1136 /* statistics */ \
1137 develop(bool, CountCompiledCalls, false, \
1138 "Count method invocations") \
1139 \
1140 develop(bool, ICMissHistogram, false, \
1141 "Produce histogram of IC misses") \
1142 \
1143 /* interpreter */ \
1144 product_pd(bool, RewriteBytecodes, \
1145 "Allow rewriting of bytecodes (bytecodes are not immutable)") \
1146 \
1147 product_pd(bool, RewriteFrequentPairs, \
1148 "Rewrite frequently used bytecode pairs into a single bytecode") \
1149 \
1150 product(bool, PrintInterpreter, false, DIAGNOSTIC, \
1151 "Print the generated interpreter code") \
1152 \
1153 product(bool, UseInterpreter, true, \
1154 "Use interpreter for non-compiled methods") \
1155 \
1156 develop(bool, UseFastSignatureHandlers, true, \
1157 "Use fast signature handlers for native calls") \
1158 \
1159 product(bool, UseLoopCounter, true, \
1160 "Increment invocation counter on backward branch") \
1161 \
1162 product_pd(bool, UseOnStackReplacement, \
1163 "Use on stack replacement, calls runtime if invoc. counter " \
1164 "overflows in loop") \
1165 \
1166 develop(bool, TraceOnStackReplacement, false, \
1167 "Trace on stack replacement") \
1168 \
1169 product_pd(bool, PreferInterpreterNativeStubs, \
1170 "Use always interpreter stubs for native methods invoked via " \
1171 "interpreter") \
1172 \
1173 develop(bool, CountBytecodes, false, \
1174 "Count number of bytecodes executed") \
1175 \
1176 develop(bool, PrintBytecodeHistogram, false, \
1177 "Print histogram of the executed bytecodes") \
1178 \
1179 develop(bool, PrintBytecodePairHistogram, false, \
1180 "Print histogram of the executed bytecode pairs") \
1181 \
1182 product(bool, PrintSignatureHandlers, false, DIAGNOSTIC, \
1183 "Print code generated for native method signature handlers") \
1184 \
1185 develop(bool, VerifyOops, false, \
1186 "Do plausibility checks for oops") \
1187 \
1188 develop(bool, CheckUnhandledOops, false, \
1189 "Check for unhandled oops in VM code") \
1190 \
1191 develop(bool, VerifyJNIFields, trueInDebug, \
1192 "Verify jfieldIDs for instance fields") \
1193 \
1194 develop(bool, VerifyActivationFrameSize, false, \
1195 "Verify that activation frame didn't become smaller than its " \
1196 "minimal size") \
1197 \
1198 develop(bool, TraceFrequencyInlining, false, \
1199 "Trace frequency based inlining") \
1200 \
1201 develop_pd(bool, InlineIntrinsics, \
1202 "Use intrinsics in Interpreter that can be statically resolved") \
1203 \
1204 product_pd(bool, ProfileInterpreter, \
1205 "Profile at the bytecode level during interpretation") \
1206 \
1207 develop_pd(bool, ProfileTraps, \
1208 "Profile deoptimization traps at the bytecode level") \
1209 \
1210 product(intx, ProfileMaturityPercentage, 20, \
1211 "number of method invocations/branches (expressed as % of " \
1212 "CompileThreshold) before using the method's profile") \
1213 range(0, 100) \
1214 \
1215 product(bool, PrintMethodData, false, DIAGNOSTIC, \
1216 "Print the results of +ProfileInterpreter at end of run") \
1217 \
1218 develop(bool, VerifyDataPointer, trueInDebug, \
1219 "Verify the method data pointer during interpreter profiling") \
1220 \
1221 develop(bool, CrashGCForDumpingJavaThread, false, \
1222 "Manually make GC thread crash then dump java stack trace; " \
1223 "Test only") \
1224 \
1225 /* compilation */ \
1226 product(bool, UseCompiler, true, \
1227 "Use Just-In-Time compilation") \
1228 \
1229 product(bool, AlwaysCompileLoopMethods, false, \
1230 "When using recompilation, never interpret methods " \
1231 "containing loops") \
1232 \
1233 product(int, AllocatePrefetchStyle, 1, \
1234 "0 = no prefetch, " \
1235 "1 = generate prefetch instructions for each allocation, " \
1236 "2 = use TLAB watermark to gate allocation prefetch, " \
1237 "3 = generate one prefetch instruction per cache line") \
1238 range(0, 3) \
1239 \
1240 product(int, AllocatePrefetchDistance, -1, \
1241 "Distance to prefetch ahead of allocation pointer. " \
1242 "-1: use system-specific value (automatically determined") \
1243 range(-1, 512) \
1244 \
1245 product(int, AllocatePrefetchLines, 3, \
1246 "Number of lines to prefetch ahead of array allocation pointer") \
1247 range(1, 64) \
1248 \
1249 product(int, AllocateInstancePrefetchLines, 1, \
1250 "Number of lines to prefetch ahead of instance allocation " \
1251 "pointer") \
1252 range(1, 64) \
1253 \
1254 product(int, AllocatePrefetchStepSize, 16, \
1255 "Step size in bytes of sequential prefetch instructions") \
1256 range(1, 512) \
1257 constraint(AllocatePrefetchStepSizeConstraintFunc,AfterMemoryInit)\
1258 \
1259 product(intx, AllocatePrefetchInstr, 0, \
1260 "Select instruction to prefetch ahead of allocation pointer") \
1261 constraint(AllocatePrefetchInstrConstraintFunc, AfterMemoryInit) \
1262 \
1263 /* deoptimization */ \
1264 product(bool, TraceDeoptimization, false, DIAGNOSTIC, \
1265 "Trace deoptimization") \
1266 \
1267 develop(bool, PrintDeoptimizationDetails, false, \
1268 "Print more information about deoptimization") \
1269 \
1270 develop(bool, DebugDeoptimization, false, \
1271 "Tracing various information while debugging deoptimization") \
1272 \
1273 product(double, SelfDestructTimer, 0.0, \
1274 "Will cause VM to terminate after a given time " \
1275 "(in fractional minutes) " \
1276 "(0.0 means off)") \
1277 range(0.0, (double)max_intx) \
1278 \
1279 product(int, MaxJavaStackTraceDepth, 1024, \
1280 "The maximum number of lines in the stack trace for Java " \
1281 "exceptions (0 means all)") \
1282 range(0, max_jint/2) \
1283 \
1284 /* notice: the max range value here is max_jint, not max_intx */ \
1285 /* because of overflow issue */ \
1286 product(intx, GuaranteedSafepointInterval, 0, DIAGNOSTIC, \
1287 "Guarantee a safepoint (at least) every so many milliseconds " \
1288 "(0 means none)") \
1289 range(0, max_jint) \
1290 \
1291 product(intx, ServiceThreadCleanupInterval, 1000, DIAGNOSTIC, \
1292 "Wake the ServiceThread to do periodic cleanup checks every so " \
1293 "many milliseconds (0 means none)") \
1294 range(0, max_jint) \
1295 \
1296 product(double, SafepointTimeoutDelay, 10000, \
1297 "Delay in milliseconds for option SafepointTimeout; " \
1298 "supports sub-millisecond resolution with fractional values.") \
1299 range(0, max_jlongDouble LP64_ONLY(/MICROUNITS)) \
1300 \
1301 product(bool, UseSystemMemoryBarrier, false, \
1302 "Try to enable system memory barrier if supported by OS") \
1303 \
1304 product(intx, NmethodSweepActivity, 4, \
1305 "Removes cold nmethods from code cache if > 0. Higher values " \
1306 "result in more aggressive sweeping") \
1307 range(0, 2000) \
1308 \
1309 develop(intx, MallocCatchPtr, -1, \
1310 "Hit breakpoint when mallocing/freeing this pointer") \
1311 \
1312 develop(int, StackPrintLimit, 100, \
1313 "number of stack frames to print in VM-level stack dump") \
1314 \
1315 product(int, ErrorLogPrintCodeLimit, 3, DIAGNOSTIC, \
1316 "max number of compiled code units to print in error log") \
1317 range(0, VMError::max_error_log_print_code) \
1318 \
1319 develop(int, MaxElementPrintSize, 256, \
1320 "maximum number of elements to print") \
1321 \
1322 develop(int, MaxStringPrintSize, 256, \
1323 "maximum number of characters to print for a java.lang.String " \
1324 "in the VM. If exceeded, an abridged version of the string is " \
1325 "printed with the middle of the string elided.") \
1326 range(2, O_BUFLEN) \
1327 \
1328 develop(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, DeoptimizeALotInterval, 5, \
1340 "Number of exits until DeoptimizeALot kicks in") \
1341 \
1342 develop(intx, ZombieALotInterval, 5, \
1343 "Number of exits until ZombieALot kicks in") \
1344 \
1345 product(ccstr, MallocLimit, nullptr, DIAGNOSTIC, \
1346 "Limit malloc allocation size from VM. Reaching a limit will " \
1347 "trigger an action (see flag). This feature requires " \
1348 "NativeMemoryTracking=summary or NativeMemoryTracking=detail." \
1349 "Usage:" \
1350 "\"-XX:MallocLimit=<size>[:<flag>]\" sets a total limit." \
1351 "\"-XX:MallocLimit=<category>:<size>[:<flag>][,<category>:<size>[:<flag>] ...]\"" \
1352 "sets one or more category-specific limits." \
1353 "<flag> defines the action upon reaching the limit:" \
1354 "\"fatal\": end VM with a fatal error at the allocation site" \
1355 "\"oom\" : will mimic a native OOM" \
1356 "If <flag> is omitted, \"fatal\" is the default." \
1357 "Examples:\n" \
1358 "-XX:MallocLimit=2g" \
1359 "-XX:MallocLimit=2g:oom" \
1360 "-XX:MallocLimit=compiler:200m:oom,code:100m") \
1361 \
1362 product(intx, TypeProfileWidth, 2, \
1363 "Number of receiver types to record in call/cast profile") \
1364 range(0, 8) \
1365 \
1366 develop(intx, BciProfileWidth, 2, \
1367 "Number of return bci's to record in ret profile") \
1368 \
1369 product(intx, PerMethodRecompilationCutoff, 400, \
1370 "After recompiling N times, stay in the interpreter (-1=>'Inf')") \
1371 range(-1, max_intx) \
1372 \
1373 product(intx, PerBytecodeRecompilationCutoff, 200, \
1374 "Per-BCI limit on repeated recompilation (-1=>'Inf')") \
1375 range(-1, max_intx) \
1376 \
1377 product(intx, PerMethodTrapLimit, 100, \
1378 "Limit on traps (of one kind) in a method (includes inlines)") \
1379 range(0, max_jint) \
1380 \
1381 product(intx, PerMethodSpecTrapLimit, 5000, EXPERIMENTAL, \
1382 "Limit on speculative traps (of one kind) in a method " \
1383 "(includes inlines)") \
1384 range(0, max_jint) \
1385 \
1386 product(intx, PerBytecodeTrapLimit, 4, \
1387 "Limit on traps (of one kind) at a particular BCI") \
1388 range(0, max_jint) \
1389 \
1390 product(int, SpecTrapLimitExtraEntries, 3, EXPERIMENTAL, \
1391 "Extra method data trap entries for speculation") \
1392 \
1393 product(double, InlineFrequencyRatio, 0.25, DIAGNOSTIC, \
1394 "Ratio of call site execution to caller method invocation") \
1395 \
1396 product(double, MinInlineFrequencyRatio, 0.0085, DIAGNOSTIC, \
1397 "Minimum ratio of call site execution to caller method" \
1398 "invocation to be considered for inlining") \
1399 \
1400 develop(intx, InlineThrowCount, 50, \
1401 "Force inlining of interpreted methods that throw this often") \
1402 range(0, max_jint) \
1403 \
1404 develop(intx, InlineThrowMaxSize, 200, \
1405 "Force inlining of throwing methods smaller than this") \
1406 range(0, max_jint) \
1407 \
1408 product(size_t, MetaspaceSize, NOT_LP64(16 * M) LP64_ONLY(21 * M), \
1409 "Initial threshold (in bytes) at which a garbage collection " \
1410 "is done to reduce Metaspace usage") \
1411 constraint(MetaspaceSizeConstraintFunc,AfterErgo) \
1412 \
1413 product(size_t, MaxMetaspaceSize, max_uintx, \
1414 "Maximum size of Metaspaces (in bytes)") \
1415 constraint(MaxMetaspaceSizeConstraintFunc,AfterErgo) \
1416 \
1417 product(size_t, CompressedClassSpaceSize, 1*G, \
1418 "Maximum size of class area in Metaspace when compressed " \
1419 "class pointers are used") \
1420 range(1*M, LP64_ONLY(4*G) NOT_LP64(max_uintx)) \
1421 \
1422 develop(size_t, CompressedClassSpaceBaseAddress, 0, \
1423 "Force the class space to be allocated at this address or " \
1424 "fails VM initialization (requires -Xshare=off.") \
1425 \
1426 develop(bool, RandomizeClassSpaceLocation, true, \
1427 "Randomize location of class space.") \
1428 \
1429 product(bool, PrintMetaspaceStatisticsAtExit, false, DIAGNOSTIC, \
1430 "Print metaspace statistics upon VM exit.") \
1431 \
1432 product(bool, PrintCompilerMemoryStatisticsAtExit, false, DIAGNOSTIC, \
1433 "Print compiler memory statistics upon VM exit.") \
1434 \
1435 product(uintx, MinHeapFreeRatio, 40, MANAGEABLE, \
1436 "The minimum percentage of heap free after GC to avoid expansion."\
1437 " For most GCs this applies to the old generation. In G1 and" \
1438 " ParallelGC it applies to the whole heap.") \
1439 range(0, 100) \
1440 constraint(MinHeapFreeRatioConstraintFunc,AfterErgo) \
1441 \
1442 product(uintx, MaxHeapFreeRatio, 70, MANAGEABLE, \
1443 "The maximum percentage of heap free after GC to avoid shrinking."\
1444 " For most GCs this applies to the old generation. In G1 and" \
1445 " ParallelGC it applies to the whole heap.") \
1446 range(0, 100) \
1447 constraint(MaxHeapFreeRatioConstraintFunc,AfterErgo) \
1448 \
1449 product(intx, SoftRefLRUPolicyMSPerMB, 1000, \
1450 "Number of milliseconds per MB of free space in the heap") \
1451 range(0, max_intx) \
1452 constraint(SoftRefLRUPolicyMSPerMBConstraintFunc,AfterMemoryInit) \
1453 \
1454 product(size_t, MinHeapDeltaBytes, ScaleForWordSize(128*K), \
1455 "The minimum change in heap space due to GC (in bytes)") \
1456 range(0, max_uintx / 2 + 1) \
1457 \
1458 product(size_t, MinMetaspaceExpansion, ScaleForWordSize(256*K), \
1459 "The minimum expansion of Metaspace (in bytes)") \
1460 range(0, max_uintx) \
1461 \
1462 product(uint, MaxMetaspaceFreeRatio, 70, \
1463 "The maximum percentage of Metaspace free after GC to avoid " \
1464 "shrinking") \
1465 range(0, 100) \
1466 constraint(MaxMetaspaceFreeRatioConstraintFunc,AfterErgo) \
1467 \
1468 product(uint, MinMetaspaceFreeRatio, 40, \
1469 "The minimum percentage of Metaspace free after GC to avoid " \
1470 "expansion") \
1471 range(0, 99) \
1472 constraint(MinMetaspaceFreeRatioConstraintFunc,AfterErgo) \
1473 \
1474 product(size_t, MaxMetaspaceExpansion, ScaleForWordSize(4*M), \
1475 "The maximum expansion of Metaspace without full GC (in bytes)") \
1476 range(0, max_uintx) \
1477 \
1478 /* stack parameters */ \
1479 product_pd(intx, StackYellowPages, \
1480 "Number of yellow zone (recoverable overflows) pages of size " \
1481 "4KB. If pages are bigger yellow zone is aligned up.") \
1482 range(MIN_STACK_YELLOW_PAGES, (DEFAULT_STACK_YELLOW_PAGES+5)) \
1483 \
1484 product_pd(intx, StackRedPages, \
1485 "Number of red zone (unrecoverable overflows) pages of size " \
1486 "4KB. If pages are bigger red zone is aligned up.") \
1487 range(MIN_STACK_RED_PAGES, (DEFAULT_STACK_RED_PAGES+2)) \
1488 \
1489 product_pd(intx, StackReservedPages, \
1490 "Number of reserved zone (reserved to annotated methods) pages" \
1491 " of size 4KB. If pages are bigger reserved zone is aligned up.") \
1492 range(MIN_STACK_RESERVED_PAGES, (DEFAULT_STACK_RESERVED_PAGES+10))\
1493 \
1494 product(bool, RestrictReservedStack, true, \
1495 "Restrict @ReservedStackAccess to trusted classes") \
1496 \
1497 /* greater stack shadow pages can't generate instruction to bang stack */ \
1498 product_pd(intx, StackShadowPages, \
1499 "Number of shadow zone (for overflow checking) pages of size " \
1500 "4KB. If pages are bigger shadow zone is aligned up. " \
1501 "This should exceed the depth of the VM and native call stack.") \
1502 range(MIN_STACK_SHADOW_PAGES, (DEFAULT_STACK_SHADOW_PAGES+30)) \
1503 \
1504 product_pd(intx, ThreadStackSize, \
1505 "Thread Stack Size (in Kbytes)") \
1506 range(0, 1 * M) \
1507 \
1508 product_pd(intx, VMThreadStackSize, \
1509 "Non-Java Thread Stack Size (in Kbytes)") \
1510 range(0, max_intx/(1 * K)) \
1511 \
1512 product_pd(intx, CompilerThreadStackSize, \
1513 "Compiler Thread Stack Size (in Kbytes)") \
1514 range(0, max_intx/(1 * K)) \
1515 \
1516 develop_pd(size_t, JVMInvokeMethodSlack, \
1517 "Stack space (bytes) required for JVM_InvokeMethod to complete") \
1518 \
1519 /* code cache parameters */ \
1520 product_pd(uintx, CodeCacheSegmentSize, EXPERIMENTAL, \
1521 "Code cache segment size (in bytes) - smallest unit of " \
1522 "allocation") \
1523 range(1, 1024) \
1524 constraint(CodeCacheSegmentSizeConstraintFunc, AfterErgo) \
1525 \
1526 product_pd(intx, CodeEntryAlignment, EXPERIMENTAL, \
1527 "Code entry alignment for generated code (in bytes)") \
1528 constraint(CodeEntryAlignmentConstraintFunc, AfterErgo) \
1529 \
1530 product_pd(intx, OptoLoopAlignment, \
1531 "Align inner loops to zero relative to this modulus") \
1532 range(1, 128) \
1533 constraint(OptoLoopAlignmentConstraintFunc, AfterErgo) \
1534 \
1535 product_pd(uintx, InitialCodeCacheSize, \
1536 "Initial code cache size (in bytes)") \
1537 constraint(VMPageSizeConstraintFunc, AtParse) \
1538 \
1539 develop_pd(uintx, CodeCacheMinimumUseSpace, \
1540 "Minimum code cache size (in bytes) required to start VM.") \
1541 range(0, max_uintx) \
1542 \
1543 product(bool, SegmentedCodeCache, false, \
1544 "Use a segmented code cache") \
1545 \
1546 product_pd(uintx, ReservedCodeCacheSize, \
1547 "Reserved code cache size (in bytes) - maximum code cache size") \
1548 constraint(VMPageSizeConstraintFunc, AtParse) \
1549 \
1550 product_pd(uintx, NonProfiledCodeHeapSize, \
1551 "Size of code heap with non-profiled methods (in bytes)") \
1552 range(0, max_uintx) \
1553 \
1554 product_pd(uintx, ProfiledCodeHeapSize, \
1555 "Size of code heap with profiled methods (in bytes)") \
1556 range(0, max_uintx) \
1557 \
1558 product_pd(uintx, NonNMethodCodeHeapSize, \
1559 "Size of code heap with non-nmethods (in bytes)") \
1560 constraint(VMPageSizeConstraintFunc, AtParse) \
1561 \
1562 product_pd(uintx, CodeCacheExpansionSize, \
1563 "Code cache expansion size (in bytes)") \
1564 range(32*K, max_uintx) \
1565 \
1566 product_pd(uintx, CodeCacheMinBlockLength, DIAGNOSTIC, \
1567 "Minimum number of segments in a code cache block") \
1568 range(1, 100) \
1569 \
1570 develop(bool, ExitOnFullCodeCache, false, \
1571 "Exit the VM if we fill the code cache") \
1572 \
1573 product(bool, UseCodeCacheFlushing, true, \
1574 "Remove cold/old nmethods from the code cache") \
1575 \
1576 product(double, SweeperThreshold, 15.0, \
1577 "Threshold when a code cache unloading GC is invoked." \
1578 "Value is percentage of ReservedCodeCacheSize.") \
1579 range(0.0, 100.0) \
1580 \
1581 product(uintx, StartAggressiveSweepingAt, 10, \
1582 "Start aggressive sweeping if X[%] of the code cache is free." \
1583 "Segmented code cache: X[%] of the non-profiled heap." \
1584 "Non-segmented code cache: X[%] of the total code cache") \
1585 range(0, 100) \
1586 \
1587 /* interpreter debugging */ \
1588 develop(intx, BinarySwitchThreshold, 5, \
1589 "Minimal number of lookupswitch entries for rewriting to binary " \
1590 "switch") \
1591 \
1592 develop(uintx, StopInterpreterAt, 0, \
1593 "Stop interpreter execution at specified bytecode number") \
1594 \
1595 develop(uintx, TraceBytecodesAt, 0, \
1596 "Trace bytecodes starting with specified bytecode number") \
1597 \
1598 develop(uintx, TraceBytecodesStopAt, 0, \
1599 "Stop bytecode tracing at the specified bytecode number") \
1600 \
1601 /* Priorities */ \
1602 product_pd(bool, UseThreadPriorities, "Use native thread priorities") \
1603 \
1604 product(int, ThreadPriorityPolicy, 0, \
1605 "0 : Normal. "\
1606 " VM chooses priorities that are appropriate for normal "\
1607 " applications. "\
1608 " On Windows applications are allowed to use higher native "\
1609 " priorities. However, with ThreadPriorityPolicy=0, VM will "\
1610 " not use the highest possible native priority, "\
1611 " THREAD_PRIORITY_TIME_CRITICAL, as it may interfere with "\
1612 " system threads. On Linux thread priorities are ignored "\
1613 " because the OS does not support static priority in "\
1614 " SCHED_OTHER scheduling class which is the only choice for "\
1615 " non-root, non-realtime applications. "\
1616 "1 : Aggressive. "\
1617 " Java thread priorities map over to the entire range of "\
1618 " native thread priorities. Higher Java thread priorities map "\
1619 " to higher native thread priorities. This policy should be "\
1620 " used with care, as sometimes it can cause performance "\
1621 " degradation in the application and/or the entire system. On "\
1622 " Linux/BSD/macOS this policy requires root privilege or an "\
1623 " extended capability.") \
1624 range(0, 1) \
1625 \
1626 product(bool, ThreadPriorityVerbose, false, \
1627 "Print priority changes") \
1628 \
1629 product(int, CompilerThreadPriority, -1, \
1630 "The native priority at which compiler threads should run " \
1631 "(-1 means no change)") \
1632 range(min_jint, max_jint) \
1633 \
1634 product(int, VMThreadPriority, -1, \
1635 "The native priority at which the VM thread should run " \
1636 "(-1 means no change)") \
1637 range(min_jint, max_jint) \
1638 \
1639 product(int, JavaPriority1_To_OSPriority, -1, \
1640 "Map Java priorities to OS priorities") \
1641 range(min_jint, max_jint) \
1642 \
1643 product(int, JavaPriority2_To_OSPriority, -1, \
1644 "Map Java priorities to OS priorities") \
1645 range(min_jint, max_jint) \
1646 \
1647 product(int, JavaPriority3_To_OSPriority, -1, \
1648 "Map Java priorities to OS priorities") \
1649 range(min_jint, max_jint) \
1650 \
1651 product(int, JavaPriority4_To_OSPriority, -1, \
1652 "Map Java priorities to OS priorities") \
1653 range(min_jint, max_jint) \
1654 \
1655 product(int, JavaPriority5_To_OSPriority, -1, \
1656 "Map Java priorities to OS priorities") \
1657 range(min_jint, max_jint) \
1658 \
1659 product(int, JavaPriority6_To_OSPriority, -1, \
1660 "Map Java priorities to OS priorities") \
1661 range(min_jint, max_jint) \
1662 \
1663 product(int, JavaPriority7_To_OSPriority, -1, \
1664 "Map Java priorities to OS priorities") \
1665 range(min_jint, max_jint) \
1666 \
1667 product(int, JavaPriority8_To_OSPriority, -1, \
1668 "Map Java priorities to OS priorities") \
1669 range(min_jint, max_jint) \
1670 \
1671 product(int, JavaPriority9_To_OSPriority, -1, \
1672 "Map Java priorities to OS priorities") \
1673 range(min_jint, max_jint) \
1674 \
1675 product(int, JavaPriority10_To_OSPriority,-1, \
1676 "Map Java priorities to OS priorities") \
1677 range(min_jint, max_jint) \
1678 \
1679 product(bool, UseCriticalJavaThreadPriority, false, EXPERIMENTAL, \
1680 "Java thread priority 10 maps to critical scheduling priority") \
1681 \
1682 product(bool, UseCriticalCompilerThreadPriority, false, EXPERIMENTAL, \
1683 "Compiler thread(s) run at critical scheduling priority") \
1684 \
1685 develop(intx, NewCodeParameter, 0, \
1686 "Testing Only: Create a dedicated integer parameter before " \
1687 "putback") \
1688 \
1689 /* new oopmap storage allocation */ \
1690 develop(intx, MinOopMapAllocation, 8, \
1691 "Minimum number of OopMap entries in an OopMapSet") \
1692 \
1693 /* recompilation */ \
1694 product_pd(intx, CompileThreshold, \
1695 "number of interpreted method invocations before (re-)compiling") \
1696 constraint(CompileThresholdConstraintFunc, AfterErgo) \
1697 \
1698 product_pd(bool, TieredCompilation, \
1699 "Enable tiered compilation") \
1700 \
1701 /* Properties for Java libraries */ \
1702 \
1703 product(uint64_t, MaxDirectMemorySize, 0, \
1704 "Maximum total size of NIO direct-buffer allocations. " \
1705 "Ignored if not explicitly set.") \
1706 range(0, max_jlong) \
1707 \
1708 /* Flags used for temporary code during development */ \
1709 \
1710 product(bool, UseNewCode, false, DIAGNOSTIC, \
1711 "Testing Only: Use the new version while testing") \
1712 \
1713 product(bool, UseNewCode2, false, DIAGNOSTIC, \
1714 "Testing Only: Use the new version while testing") \
1715 \
1716 product(bool, UseNewCode3, false, DIAGNOSTIC, \
1717 "Testing Only: Use the new version while testing") \
1718 \
1719 develop(bool, UseDebuggerErgo, false, \
1720 "Debugging Only: Adjust the VM to be more debugger-friendly. " \
1721 "Turns on the other UseDebuggerErgo* flags") \
1722 \
1723 develop(bool, UseDebuggerErgo1, false, \
1724 "Debugging Only: Enable workarounds for debugger induced " \
1725 "os::processor_id() >= os::processor_count() problems") \
1726 \
1727 develop(bool, UseDebuggerErgo2, false, \
1728 "Debugging Only: Limit the number of spawned JVM threads") \
1729 \
1730 develop(bool, EnableJVMTIStackDepthAsserts, true, \
1731 "Enable JVMTI asserts related to stack depth checks") \
1732 \
1733 /* flags for performance data collection */ \
1734 \
1735 product(bool, UsePerfData, true, \
1736 "Flag to disable jvmstat instrumentation for performance testing "\
1737 "and problem isolation purposes") \
1738 \
1739 product(bool, PerfDataSaveToFile, false, \
1740 "Save PerfData memory to hsperfdata_<pid> file on exit") \
1741 \
1742 product(ccstr, PerfDataSaveFile, nullptr, \
1743 "Save PerfData memory to the specified absolute pathname. " \
1744 "The string %p in the file name (if present) " \
1745 "will be replaced by pid") \
1746 \
1747 product(int, PerfDataSamplingInterval, 50, \
1748 "Data sampling interval (in milliseconds)") \
1749 range(PeriodicTask::min_interval, max_jint) \
1750 constraint(PerfDataSamplingIntervalFunc, AfterErgo) \
1751 \
1752 product(bool, PerfDisableSharedMem, false, \
1753 "Store performance data in standard memory") \
1754 \
1755 product(int, PerfDataMemorySize, 32*K, \
1756 "Size of performance data memory region. Will be rounded " \
1757 "up to a multiple of the native os page size.") \
1758 range(128, 32*64*K) \
1759 \
1760 product(int, PerfMaxStringConstLength, 1024, \
1761 "Maximum PerfStringConstant string length before truncation") \
1762 range(32, 32*K) \
1763 \
1764 product(bool, PerfAllowAtExitRegistration, false, \
1765 "Allow registration of atexit() methods") \
1766 \
1767 product(bool, PerfBypassFileSystemCheck, false, \
1768 "Bypass Win32 file system criteria checks (Windows Only)") \
1769 \
1770 product(int, UnguardOnExecutionViolation, 0, \
1771 "Unguard page and retry on no-execute fault (Win32 only) " \
1772 "0=off, 1=conservative, 2=aggressive") \
1773 range(0, 2) \
1774 \
1775 /* Serviceability Support */ \
1776 \
1777 product(bool, ManagementServer, false, \
1778 "Create JMX Management Server") \
1779 \
1780 product(bool, DisableAttachMechanism, false, \
1781 "Disable mechanism that allows tools to attach to this VM") \
1782 \
1783 product(bool, StartAttachListener, false, \
1784 "Always start Attach Listener at VM startup") \
1785 \
1786 product(bool, EnableDynamicAgentLoading, true, \
1787 "Allow tools to load agents with the attach mechanism") \
1788 \
1789 product(bool, PrintConcurrentLocks, false, MANAGEABLE, \
1790 "Print java.util.concurrent locks in thread dump") \
1791 \
1792 product(bool, PrintMethodHandleStubs, false, DIAGNOSTIC, \
1793 "Print generated stub code for method handles") \
1794 \
1795 product(bool, VerifyMethodHandles, trueInDebug, DIAGNOSTIC, \
1796 "perform extra checks when constructing method handles") \
1797 \
1798 product(bool, IgnoreAssertUnsetFields, false, DIAGNOSTIC, \
1799 "Ignore assert_unset_fields") \
1800 \
1801 product(bool, ShowHiddenFrames, false, DIAGNOSTIC, \
1802 "show method handle implementation frames (usually hidden)") \
1803 \
1804 product(bool, ShowCarrierFrames, false, DIAGNOSTIC, \
1805 "show virtual threads' carrier frames in exceptions") \
1806 \
1807 product(bool, TrustFinalNonStaticFields, false, EXPERIMENTAL, \
1808 "trust final non-static declarations for constant folding") \
1809 \
1810 product(bool, FoldStableValues, true, DIAGNOSTIC, \
1811 "Optimize loads from stable fields (marked w/ @Stable)") \
1812 \
1813 product(int, UseBootstrapCallInfo, 1, DIAGNOSTIC, \
1814 "0: when resolving InDy or ConDy, force all BSM arguments to be " \
1815 "resolved before the bootstrap method is called; 1: when a BSM " \
1816 "that may accept a BootstrapCallInfo is detected, use that API " \
1817 "to pass BSM arguments, which allows the BSM to delay their " \
1818 "resolution; 2+: stress test the BCI API by calling more BSMs " \
1819 "via that API, instead of with the eagerly-resolved array.") \
1820 \
1821 product(bool, PauseAtStartup, false, DIAGNOSTIC, \
1822 "Causes the VM to pause at startup time and wait for the pause " \
1823 "file to be removed (default: ./vm.paused.<pid>)") \
1824 \
1825 product(ccstr, PauseAtStartupFile, nullptr, DIAGNOSTIC, \
1826 "The file to create and for whose removal to await when pausing " \
1827 "at startup. (default: ./vm.paused.<pid>)") \
1828 \
1829 product(bool, PauseAtExit, false, DIAGNOSTIC, \
1830 "Pause and wait for keypress on exit if a debugger is attached") \
1831 \
1832 product(bool, DTraceMethodProbes, false, \
1833 "Enable dtrace tool probes for method-entry and method-exit") \
1834 \
1835 product(bool, DTraceAllocProbes, false, \
1836 "Enable dtrace tool probes for object allocation") \
1837 \
1838 product(bool, DTraceMonitorProbes, false, \
1839 "Enable dtrace tool probes for monitor events") \
1840 \
1841 product(bool, RelaxAccessControlCheck, false, \
1842 "Relax the access control checks in the verifier") \
1843 \
1844 product(uintx, StringTableSize, defaultStringTableSize, \
1845 "Number of buckets in the interned String table " \
1846 "(will be rounded to nearest higher power of 2)") \
1847 range(minimumStringTableSize, 16777216ul /* 2^24 */) \
1848 \
1849 product(uintx, SymbolTableSize, defaultSymbolTableSize, EXPERIMENTAL, \
1850 "Number of buckets in the JVM internal Symbol table") \
1851 range(minimumSymbolTableSize, 16777216ul /* 2^24 */) \
1852 \
1853 product(bool, UseStringDeduplication, false, \
1854 "Use string deduplication") \
1855 \
1856 product(uint, StringDeduplicationAgeThreshold, 3, \
1857 "A string must reach this age (or be promoted to an old region) " \
1858 "to be considered for deduplication") \
1859 range(1, markWord::max_age) \
1860 \
1861 product(size_t, StringDeduplicationInitialTableSize, 500, EXPERIMENTAL, \
1862 "Approximate initial number of buckets in the table") \
1863 range(1, 1 * G) \
1864 \
1865 product(double, StringDeduplicationGrowTableLoad, 14.0, EXPERIMENTAL, \
1866 "Entries per bucket above which the table should be expanded") \
1867 range(0.1, 1000.0) \
1868 \
1869 product(double, StringDeduplicationShrinkTableLoad, 1.0, EXPERIMENTAL, \
1870 "Entries per bucket below which the table should be shrunk") \
1871 range(0.01, 100.0) \
1872 \
1873 product(double, StringDeduplicationTargetTableLoad, 7.0, EXPERIMENTAL, \
1874 "Desired entries per bucket when resizing the table") \
1875 range(0.01, 1000.0) \
1876 \
1877 product(size_t, StringDeduplicationCleanupDeadMinimum, 100, EXPERIMENTAL, \
1878 "Minimum number of dead table entries for cleaning the table") \
1879 \
1880 product(int, StringDeduplicationCleanupDeadPercent, 5, EXPERIMENTAL, \
1881 "Minimum percentage of dead table entries for cleaning the table") \
1882 range(1, 100) \
1883 \
1884 product(bool, StringDeduplicationResizeALot, false, DIAGNOSTIC, \
1885 "Force more frequent table resizing") \
1886 \
1887 product(uint64_t, StringDeduplicationHashSeed, 0, DIAGNOSTIC, \
1888 "Seed for the table hashing function; 0 requests computed seed") \
1889 \
1890 product(bool, WhiteBoxAPI, false, DIAGNOSTIC, \
1891 "Enable internal testing APIs") \
1892 \
1893 product(bool, AlwaysAtomicAccesses, false, EXPERIMENTAL, \
1894 "Accesses to all variables should always be atomic") \
1895 \
1896 product(bool, UseUnalignedAccesses, false, DIAGNOSTIC, \
1897 "Use unaligned memory accesses in Unsafe") \
1898 \
1899 product_pd(bool, PreserveFramePointer, \
1900 "Use the FP register for holding the frame pointer " \
1901 "and not as a general purpose register.") \
1902 \
1903 product(size_t, AsyncLogBufferSize, 2*M, \
1904 "Memory budget (in bytes) for the buffer of Asynchronous " \
1905 "Logging (-Xlog:async).") \
1906 range(DEBUG_ONLY(192) NOT_DEBUG(100*K), 50*M) \
1907 \
1908 product(bool, CheckIntrinsics, true, DIAGNOSTIC, \
1909 "When a class C is loaded, check that " \
1910 "(1) all intrinsics defined by the VM for class C are present "\
1911 "in the loaded class file and are marked with the " \
1912 "@IntrinsicCandidate annotation, that " \
1913 "(2) there is an intrinsic registered for all loaded methods " \
1914 "that are annotated with the @IntrinsicCandidate annotation, " \
1915 "and that " \
1916 "(3) no orphan methods exist for class C (i.e., methods for " \
1917 "which the VM declares an intrinsic but that are not declared "\
1918 "in the loaded class C. " \
1919 "Check (3) is available only in debug builds.") \
1920 \
1921 product_pd(intx, InitArrayShortSize, DIAGNOSTIC, \
1922 "Threshold small size (in bytes) for clearing arrays. " \
1923 "Anything this size or smaller may get converted to discrete " \
1924 "scalar stores.") \
1925 range(0, max_intx) \
1926 constraint(InitArrayShortSizeConstraintFunc, AfterErgo) \
1927 \
1928 product(ccstr, AllocateHeapAt, nullptr, \
1929 "Path to the directory where a temporary file will be created " \
1930 "to use as the backing store for Java Heap.") \
1931 \
1932 product_pd(bool, VMContinuations, EXPERIMENTAL, \
1933 "Enable VM continuations support") \
1934 \
1935 develop(bool, LoomDeoptAfterThaw, false, \
1936 "Deopt stack after thaw") \
1937 \
1938 develop(bool, LoomVerifyAfterThaw, false, \
1939 "Verify stack after thaw") \
1940 \
1941 develop(bool, VerifyContinuations, false, \
1942 "Verify continuation consistency") \
1943 \
1944 develop(bool, UseContinuationFastPath, true, \
1945 "Use fast-path frame walking in continuations") \
1946 \
1947 develop(int, VerifyMetaspaceInterval, DEBUG_ONLY(500) NOT_DEBUG(0), \
1948 "Run periodic metaspace verifications (0 - none, " \
1949 "1 - always, >1 every nth interval)") \
1950 \
1951 product(bool, ShowRegistersOnAssert, true, DIAGNOSTIC, \
1952 "On internal errors, include registers in error report.") \
1953 \
1954 product(bool, UseSwitchProfiling, true, DIAGNOSTIC, \
1955 "leverage profiling for table/lookup switch") \
1956 \
1957 develop(bool, TraceMemoryWriteback, false, \
1958 "Trace memory writeback operations") \
1959 \
1960 JFR_ONLY(product(bool, FlightRecorder, false, \
1961 "(Deprecated) Enable Flight Recorder")) \
1962 \
1963 JFR_ONLY(product(ccstr, FlightRecorderOptions, nullptr, \
1964 "Flight Recorder options")) \
1965 \
1966 JFR_ONLY(product(ccstr, StartFlightRecording, nullptr, \
1967 "Start flight recording with options")) \
1968 \
1969 product(bool, UseFastUnorderedTimeStamps, false, EXPERIMENTAL, \
1970 "Use platform unstable time where supported for timestamps only") \
1971 \
1972 product(bool, EnableValhalla, true, \
1973 "Enable experimental Valhalla features") \
1974 \
1975 product_pd(bool, InlineTypePassFieldsAsArgs, \
1976 "Pass each inline type field as an argument at calls") \
1977 \
1978 product_pd(bool, InlineTypeReturnedAsFields, \
1979 "Return fields instead of an inline type reference") \
1980 \
1981 develop(bool, StressCallingConvention, false, \
1982 "Stress the scalarized calling convention.") \
1983 \
1984 product(ccstrlist, ForceNonTearable, "", DIAGNOSTIC, \
1985 "List of inline classes which are forced to be atomic " \
1986 "(whitespace and commas separate names, " \
1987 "and leading and trailing stars '*' are wildcards)") \
1988 \
1989 product(bool, DeoptimizeNMethodBarriersALot, false, DIAGNOSTIC, \
1990 "Make nmethod barriers deoptimise a lot.") \
1991 \
1992 develop(bool, VerifyCrossModifyFence, \
1993 false AARCH64_ONLY(DEBUG_ONLY(||true)), \
1994 "Mark all threads after a safepoint, and clear on a modify " \
1995 "fence. Add cleanliness checks.") \
1996 \
1997 product(int, LockingMode, LM_LIGHTWEIGHT, \
1998 "(Deprecated) Select locking mode: " \
1999 "0: (Deprecated) monitors only (LM_MONITOR), " \
2000 "1: (Deprecated) monitors & legacy stack-locking (LM_LEGACY), " \
2001 "2: monitors & new lightweight locking (LM_LIGHTWEIGHT, default)") \
2002 range(0, 2) \
2003 \
2004 product(bool, UseObjectMonitorTable, false, DIAGNOSTIC, \
2005 "With Lightweight Locking mode, use a table to record inflated " \
2006 "monitors rather than the first word of the object.") \
2007 \
2008 product(int, LightweightFastLockingSpins, 13, DIAGNOSTIC, \
2009 "Specifies the number of times lightweight fast locking will " \
2010 "attempt to CAS the markWord before inflating. Between each " \
2011 "CAS it will spin for exponentially more time, resulting in " \
2012 "a total number of spins on the order of O(2^value)") \
2013 range(1, 30) \
2014 \
2015 product(uint, TrimNativeHeapInterval, 0, \
2016 "Interval, in ms, at which the JVM will trim the native heap if " \
2017 "the platform supports that. Lower values will reclaim memory " \
2018 "more eagerly at the cost of higher overhead. A value of 0 " \
2019 "(default) disables native heap trimming.") \
2020 range(0, UINT_MAX) \
2021 \
2022 develop(bool, SimulateFullAddressSpace, false, \
2023 "Simulates a very populated, fragmented address space; no " \
2024 "targeted reservations will succeed.") \
2025 \
2026 product(bool, ProfileExceptionHandlers, true, \
2027 "Profile exception handlers") \
2028 \
2029 product(bool, AlwaysRecordEvolDependencies, true, EXPERIMENTAL, \
2030 "Unconditionally record nmethod dependencies on class " \
2031 "rewriting/transformation independently of the JVMTI " \
2032 "can_{retransform/redefine}_classes capabilities.") \
2033 \
2034 product(bool, UseSecondarySupersCache, true, DIAGNOSTIC, \
2035 "Use secondary supers cache during subtype checks.") \
2036 \
2037 product(bool, UseSecondarySupersTable, false, DIAGNOSTIC, \
2038 "Use hash table to lookup secondary supers.") \
2039 \
2040 product(bool, VerifySecondarySupers, false, DIAGNOSTIC, \
2041 "Check that linear and hashed secondary lookups return the same result.") \
2042 \
2043 product(bool, StressSecondarySupers, false, DIAGNOSTIC, \
2044 "Use a terrible hash function in order to generate many collisions.") \
2045 \
2046 product(bool, UseThreadsLockThrottleLock, true, DIAGNOSTIC, \
2047 "Use an extra lock during Thread start and exit to alleviate" \
2048 "contention on Threads_lock.") \
2049
2050 // end of RUNTIME_FLAGS
2051
2052 DECLARE_FLAGS(LP64_RUNTIME_FLAGS)
2053 DECLARE_ARCH_FLAGS(ARCH_FLAGS)
2054 DECLARE_FLAGS(RUNTIME_FLAGS)
2055 DECLARE_FLAGS(RUNTIME_OS_FLAGS)
2056
2057 #endif // SHARE_RUNTIME_GLOBALS_HPP