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