1. 关键的Java JVM选项和参数

让我们来看看在Java环境中可以配置的21个最重要的JVM选项和参数。

-Xms：将设置JVM的初始堆大小。-Xmx：将设置JVM的最大堆大小。-Xss：将设置每个线程的内部使用的线程堆栈的大小。-XX：+UseCompressedOops：启用使用压缩对象指针以减少内存使用的功能。-XX：+UseThreadPriorities：将指示JVM使用本机线程优先级。-XX：PermSize：将设置垃圾收集器永久生成空间的初始大小。-XX：MaxPermSize：将设置垃圾收集器永久生成空间的最大大小。-XX：NewSize：设置年轻代空间的初始大小。-XX：MaxNewSize：设置年轻代空间的最大大小。-XX：SurvivorRatio：设置伊甸园空间与幸存者空间的比例。-XX：MaxTenuringThreshold：设置幸存者空间中对象的最大年龄。-XX：+UseParNewGC：指示JVM使用新的并行生成垃圾收集器。-XX：+UseSerialGC：指示JVM使用串行垃圾收集器。-XX：+UseG1GC：指示JVM使用Garbage First（G1）垃圾收集器。-XX：+UseZGC：指示JVM使用ZGC垃圾收集器。-XX：+HeapDumpOnOutOfMemoryError：告诉JVM在发生OutOfMemoryError时创建堆转储文件。-XX：HeapDumpPath：为JVM提供自定义路径，在堆转储期间写入堆的内容。-Djava.library.path：允许您指定在运行时需要的本机库的路径。-Duser.timezone：允许您为JVM设置自定义时区。-XX：+PrintGCDetails：指示JVM打印详细的垃圾回收日志，以帮助您进行GC优化。-XX：+PrintFlagsFinal-version：将打印在JVM上设置的所有当前配置的标志和选项。2. 如何使用Java JVM选项

所有这些JVM选项都可以通过将它们作为文本附加到Java运行时命令后来简单地使用。

例如，以下命令将使用六个不同的参数运行名为Go的应用程序，以优化内存分配和垃圾回收：

java Go -XX:MaxPermSize=128m -XX:MaxNewSize=256m -Xms768m -Xmx768m -XX:SurvivorRatio=128 -XX:MaxTenuringThreshold=0

Java JVM选项可用于管理内存和优化GC性能

3. 最常用的JVM参数

在列举的所有 JVM 选项中，最常用的是 Xms 和 Xmx，分别设置最小堆大小和最大堆大小。

下面的示例将最小堆大小设置为 768 MB，最大堆大小设置为 2 GB。

-Xms768m-Xmx2048

Java的一个优点是它为开发者执行垃圾回收，这使得应用程序更加健壮，更不容易发生内存泄漏问题。

有许多垃圾回收器可用，具有各种暂停行为和停顿时间。

在启动运行时，您只能使用以下 Java JVM 选项之一选择一个垃圾收集器：

-XX:+UseSerialGC-XX:+UseParallelGC-XX:+USeParNewGC-XX:+UseG1GC-XX:+UseZGC

VM实现了一种分代垃圾回收算法，它积极监控新对象，而很少检查旧对象。JVM管理eden空间、tenured空间甚至PermGen空间的方式可以通过JVM选项进行配置，如下：

-XX:MaxPermSize-XX:PermSize-XX:NewSize-XX:MaxNewSize-XX:SurvivorRatio-XX:MaxTenuringThreshold

JVM还提供了一些打印方法，允许您查看Java运行时的状态。有用的JVM打印选项包括：

-XX:+PrintGCDetails-XX:+PrintGCDateStamps-XX:+PrintHeapAtGC-XX:+PrintCommandLineFlags-XX:+PrintFlagsFinal

PrintFlagsFinal是一项有趣的JVM选项，它将显示所有JVM标志设置的详细信息，输出内容有超过500行。本文介绍的Java JVM选项已经全部讲解完毕，如果你对PrintFlagsFinal JVM标志的详细输出感兴趣，可以查看上文提到的输出内容。

$ java -XX:+PrintFlagsFinal -version[Global flags]int ActiveProcessorCount = -1uintx AdaptiveSizeDecrementScaleFactor = 4uintx AdaptiveSizeMajorGCDecayTimeScale = 10uintx AdaptiveSizePolicyCollectionCostMargin = 50uintx AdaptiveSizePolicyInitializingSteps = 20uintx AdaptiveSizePolicyOutputInterval = 0uintx AdaptiveSizePolicyWeight = 10uintx AdaptiveSizeThroughPutPolicy = 0uintx AdaptiveTimeWeight = 25bool AggressiveHeap = falseintx AliasLevel = 3bool AlignVector = falseccstr AllocateHeapAt =intx AllocateInstancePrefetchLines = 1intx AllocatePrefetchDistance = 256intx AllocatePrefetchInstr = 0intx AllocatePrefetchLines = 3intx AllocatePrefetchStepSize = 64intx AllocatePrefetchStyle = 1bool AllowParallelDefineClass = falsebool AllowRedefinitionToAddDeleteMethods = falsebool AllowUserSignalHandlers = falsebool AllowVectorizeOnDemand = truebool AlwaysActAsServerClassMachine = falsebool AlwaysCompileLoopMethods = falsebool AlwaysLockClassLoader = falsebool AlwaysPreTouch = falsebool AlwaysRestoreFPU = falsebool AlwaysTenure = falseccstr ArchiveClassesAtExit =intx ArrayCopyLoadStoreMaxElem = 8size_t AsyncLogBufferSize = 2097152intx AutoBoxCacheMax = 128intx BCEATraceLevel = 0bool BackgroundCompilation = truesize_t BaseFootPrintEstimate = 268435456intx BiasedLockingBulkRebiasThreshold = 20intx BiasedLockingBulkRevokeThreshold = 40intx BiasedLockingDecayTime = 25000intx BiasedLockingStartupDelay = 0bool BlockLayoutByFrequency = trueintx BlockLayoutMinDiamondPercentage = 20bool BlockLayoutRotateLoops = trueintx C1InlineStackLimit = 5intx C1MaxInlineLevel = 9intx C1MaxInlineSize = 35intx C1MaxRecursiveInlineLevel = 1intx C1MaxTrivialSize = 6bool C1OptimizeVirtualCallProfiling = truebool C1ProfileBranches = truebool C1ProfileCalls = truebool C1ProfileCheckcasts = truebool C1ProfileInlinedCalls = truebool C1ProfileVirtualCalls = truebool C1UpdateMethodData = trueintx CICompilerCount = 4bool CICompilerCountPerCPU = truebool CITime = falsebool CheckJNICalls = falsebool ClassUnloading = truebool ClassUnloadingWithConcurrentMark = truebool ClipInlining = trueuintx CodeCacheExpansionSize = 65536bool CompactStrings = trueccstr CompilationMode = defaultccstrlist CompileCommand =ccstr CompileCommandFile =ccstrlist CompileOnly =intx CompileThreshold = 10000double CompileThresholdScaling = 1.000000intx CompilerThreadPriority = -1intx CompilerThreadStackSize = 0size_t CompressedClassSpaceSize = 1073741824uint ConcGCThreads = 3intx ConditionalMoveLimit = 3intx ContendedPaddingWidth = 128bool CrashOnOutOfMemoryError = falsebool CreateCoredumpOnCrash = truebool CriticalJNINatives = falsebool DTraceAllocProbes = falsebool DTraceMethodProbes = falsebool DTraceMonitorProbes = falsebool DisableAttachMechanism = falsebool DisableExplicitGC = falsebool DisplayVMOutputToStderr = falsebool DisplayVMOutputToStdout = falsebool DoEscapeAnalysis = truebool DoReserveCopyInSuperWord = truebool DontCompileHugeMethods = truebool DontYieldALot = falseccstr DumpLoadedClassList =bool DumpReplayDataOnError = truebool DumpSharedSpaces = falsebool DynamicDumpSharedSpaces = falsebool EagerXrunInit = falseintx EliminateAllocationArraySizeLimit = 64bool EliminateAllocations = truebool EliminateAutoBox = truebool EliminateLocks = truebool EliminateNestedLocks = truebool EnableContended = truebool EnableDynamicAgentLoading = truesize_t ErgoHeapSizeLimit = 0ccstr ErrorFile =bool ErrorFileToStderr = falsebool ErrorFileToStdout = falseuint64_t ErrorLogTimeout = 120double EscapeAnalysisTimeout = 20.000000bool EstimateArgEscape = truebool ExecutingUnitTests = falsebool ExitOnOutOfMemoryError = falsebool ExplicitGCInvokesConcurrent = falsebool ExtendedDTraceProbes = falsebool ExtensiveErrorReports = falseccstr ExtraSharedClassListFile =bool FilterSpuriousWakeups = truebool FlightRecorder = falseccstr FlightRecorderOptions =bool ForceTimeHighResolution = falseintx FreqInlineSize = 325double G1ConcMarkStepDurationMillis = 10.000000uintx G1ConcRSHotCardLimit = 4size_t G1ConcRSLogCacheSize = 10size_t G1ConcRefinementGreenZone = 0size_t G1ConcRefinementRedZone = 0uintx G1ConcRefinementServiceIntervalMillis = 300uint G1ConcRefinementThreads = 10size_t G1ConcRefinementThresholdStep = 2size_t G1ConcRefinementYellowZone = 0uintx G1ConfidencePercent = 50size_t G1HeapRegionSize = 2097152uintx G1HeapWastePercent = 5uintx G1MixedGCCountTarget = 8uintx G1PeriodicGCInterval = 0bool G1PeriodicGCInvokesConcurrent = truedouble G1PeriodicGCSystemLoadThreshold = 0.000000intx G1RSetRegionEntries = 512intx G1RSetSparseRegionEntries = 16intx G1RSetUpdatingPauseTimePercent = 10uint G1RefProcDrainInterval = 1000uintx G1ReservePercent = 10uintx G1SATBBufferEnqueueingThresholdPercent = 60size_t G1SATBBufferSize = 1024size_t G1UpdateBufferSize = 256bool G1UseAdaptiveConcRefinement = truebool G1UseAdaptiveIHOP = trueuintx GCDrainStackTargetSize = 64uintx GCHeapFreeLimit = 2uintx GCLockerEdenExpansionPercent = 5uintx GCPauseIntervalMillis = 201uintx GCTimeLimit = 98uintx GCTimeRatio = 12size_t HeapBaseMinAddress = 2147483648bool HeapDumpAfterFullGC = falsebool HeapDumpBeforeFullGC = falseintx HeapDumpGzipLevel = 0bool HeapDumpOnOutOfMemoryError = falseccstr HeapDumpPath =uintx HeapFirstMaximumCompactionCount = 3uintx HeapMaximumCompactionInterval = 20uintx HeapSearchSteps = 3size_t HeapSizePerGCThread = 43620760bool IgnoreEmptyClassPaths = falsebool IgnoreUnrecognizedVMOptions = falseuintx IncreaseFirstTierCompileThresholdAt = 50bool IncrementalInline = trueuintx InitialCodeCacheSize = 2555904size_t InitialHeapSize = 268435456uintx InitialRAMFraction = 64double InitialRAMPercentage = 1.562500uintx InitialSurvivorRatio = 8uintx InitialTenuringThreshold = 7uintx InitiatingHeapOccupancyPercent = 45bool Inline = trueccstr InlineDataFile =intx InlineSmallCode = 2500bool InlineSynchronizedMethods = trueintx InteriorEntryAlignment = 16intx InterpreterProfilePercentage = 33bool JavaMonitorsInStackTrace = trueintx JavaPriority10_To_OSPriority = -1intx JavaPriority1_To_OSPriority = -1intx JavaPriority2_To_OSPriority = -1intx JavaPriority3_To_OSPriority = -1intx JavaPriority4_To_OSPriority = -1intx JavaPriority5_To_OSPriority = -1intx JavaPriority6_To_OSPriority = -1intx JavaPriority7_To_OSPriority = -1intx JavaPriority8_To_OSPriority = -1intx JavaPriority9_To_OSPriority = -1size_t LargePageHeapSizeThreshold = 134217728size_t LargePageSizeInBytes = 0intx LiveNodeCountInliningCutoff = 40000intx LoopMaxUnroll = 16intx LoopOptsCount = 43intx LoopPercentProfileLimit = 10uintx LoopStripMiningIter = 1000uintx LoopStripMiningIterShortLoop = 100intx LoopUnrollLimit = 60intx LoopUnrollMin = 4bool LoopUnswitching = truebool ManagementServer = falsesize_t MarkStackSize = 4194304size_t MarkStackSizeMax = 536870912uint MarkSweepAlwaysCompactCount = 4uintx MarkSweepDeadRatio = 5intx MaxBCEAEstimateLevel = 5intx MaxBCEAEstimateSize = 150uint64_t MaxDirectMemorySize = 0bool MaxFDLimit = trueuintx MaxGCMinorPauseMillis = 18446744073709551615uintx MaxGCPauseMillis = 200uintx MaxHeapFreeRatio = 70size_t MaxHeapSize = 4282384384intx MaxInlineLevel = 15intx MaxInlineSize = 35intx MaxJNILocalCapacity = 65536intx MaxJavaStackTraceDepth = 1024intx MaxJumpTableSize = 65000intx MaxJumpTableSparseness = 5intx MaxLabelRootDepth = 1100intx MaxLoopPad = 15size_t MaxMetaspaceExpansion = 5439488uintx MaxMetaspaceFreeRatio = 70size_t MaxMetaspaceSize = 18446744073709551615size_t MaxNewSize = 2569011200intx MaxNodeLimit = 80000uint64_t MaxRAM = 137438953472uintx MaxRAMFraction = 4double MaxRAMPercentage = 25.000000intx MaxRecursiveInlineLevel = 1uintx MaxTenuringThreshold = 15intx MaxTrivialSize = 6intx MaxVectorSize = 32ccstr MetaspaceReclaimPolicy = balancedsize_t MetaspaceSize = 22020096bool MethodFlushing = truesize_t MinHeapDeltaBytes = 2097152uintx MinHeapFreeRatio = 40size_t MinHeapSize = 8388608intx MinInliningThreshold = 250intx MinJumpTableSize = 10size_t MinMetaspaceExpansion = 327680uintx MinMetaspaceFreeRatio = 40uintx MinRAMFraction = 2double MinRAMPercentage = 50.000000uintx MinSurvivorRatio = 3size_t MinTLABSize = 2048intx MultiArrayExpandLimit = 6uintx NUMAChunkResizeWeight = 20size_t NUMAInterleaveGranularity = 2097152uintx NUMAPageScanRate = 256size_t NUMASpaceResizeRate = 1073741824bool NUMAStats = falseccstr NativeMemoryTracking = offbool NeverActAsServerClassMachine = falsebool NeverTenure = falseuintx NewRatio = 2size_t NewSize = 1363144size_t NewSizeThreadIncrease = 5320intx NmethodSweepActivity = 10intx NodeLimitFudgeFactor = 2000uintx NonNMethodCodeHeapSize = 5839372uintx NonProfiledCodeHeapSize = 122909434intx NumberOfLoopInstrToAlign = 4intx ObjectAlignmentInBytes = 8 {size_t OldPLABSize = 1024size_t OldSize = 5452592bool OmitStackTraceInFastThrow = trueccstrlist OnError =ccstrlist OnOutOfMemoryError =intx OnStackReplacePercentage = 140bool OptimizeFill = falsebool OptimizePtrCompare = truebool OptimizeStringConcat = truebool OptoBundling = falseintx OptoLoopAlignment = 16bool OptoRegScheduling = truebool OptoScheduling = falseuintx PLABWeight = 75bool PSChunkLargeArrays = trueint ParGCArrayScanChunk = 50uintx ParallelGCBufferWastePct = 10uint ParallelGCThreads = 10size_t ParallelOldDeadWoodLimiterMean = 50size_t ParallelOldDeadWoodLimiterStdDev = 80bool ParallelRefProcBalancingEnabled = truebool ParallelRefProcEnabled = truebool PartialPeelAtUnsignedTests = truebool PartialPeelLoop = trueintx PartialPeelNewPhiDelta = 0uintx PausePadding = 1intx PerBytecodeRecompilationCutoff = 200intx PerBytecodeTrapLimit = 4intx PerMethodRecompilationCutoff = 400intx PerMethodTrapLimit = 100bool PerfAllowAtExitRegistration = falsebool PerfBypassFileSystemCheck = falseintx PerfDataMemorySize = 32768intx PerfDataSamplingInterval = 50ccstr PerfDataSaveFile =bool PerfDataSaveToFile = falsebool PerfDisableSharedMem = falseintx PerfMaxStringConstLength = 1024size_t PreTouchParallelChunkSize = 1073741824bool PreferInterpreterNativeStubs = falseintx PrefetchCopyIntervalInBytes = 576intx PrefetchFieldsAhead = 1intx PrefetchScanIntervalInBytes = 576bool PreserveAllAnnotations = falsebool PreserveFramePointer = falsesize_t PretenureSizeThreshold = 0bool PrintClassHistogram = falsebool PrintCodeCache = falsebool PrintCodeCacheOnCompilation = falsebool PrintCommandLineFlags = falsebool PrintCompilation = falsebool PrintConcurrentLocks = falsebool PrintExtendedThreadInfo = falsebool PrintFlagsFinal = truebool PrintFlagsInitial = falsebool PrintFlagsRanges = falsebool PrintGC = falsebool PrintGCDetails = falsebool PrintHeapAtSIGBREAK = truebool PrintSharedArchiveAndExit = falsebool PrintSharedDictionary = falsebool PrintStringTableStatistics = falsebool PrintTieredEvents = falsebool PrintVMOptions = falsebool PrintWarnings = trueuintx ProcessDistributionStride = 4bool ProfileInterpreter = trueintx ProfileMaturityPercentage = 20uintx ProfiledCodeHeapSize = 122909434uintx PromotedPadding = 3uintx QueuedAllocationWarningCount = 0int RTMRetryCount = 5bool RangeCheckElimination = truebool ReassociateInvariants = truebool RecordDynamicDumpInfo = falsebool ReduceBulkZeroing = truebool ReduceFieldZeroing = truebool ReduceInitialCardMarks = truebool ReduceSignalUsage = falseintx RefDiscoveryPolicy = 0bool RegisterFinalizersAtInit = truebool RelaxAccessControlCheck = falseccstr ReplayDataFile =bool RequireSharedSpaces = falseuintx ReservedCodeCacheSize = 251658240bool ResizePLAB = truebool ResizeTLAB = truebool RestoreMXCSROnJNICalls = falsebool RestrictContended = truebool RestrictReservedStack = truebool RewriteBytecodes = truebool RewriteFrequentPairs = truebool SafepointTimeout = falseintx SafepointTimeoutDelay = 10000bool ScavengeBeforeFullGC = falsebool SegmentedCodeCache = trueintx SelfDestructTimer = 0ccstr SharedArchiveConfigFile =ccstr SharedArchiveFile =size_t SharedBaseAddress = 34359738368ccstr SharedClassListFile =uintx SharedSymbolTableBucketSize = 4ccstr ShenandoahGCHeuristics = adaptiveccstr ShenandoahGCMode = satbbool ShowCodeDetailsInExceptionMessages = truebool ShowMessageBoxOnError = falsebool ShrinkHeapInSteps = truesize_t SoftMaxHeapSize = 4282384384intx SoftRefLRUPolicyMSPerMB = 1000bool SplitIfBlocks = trueintx StackRedPages = 1intx StackReservedPages = 0intx StackShadowPages = 7bool StackTraceInThrowable = trueintx StackYellowPages = 3uintx StartAggressiveSweepingAt = 10bool StartAttachListener = falseccstr StartFlightRecording =uint StringDeduplicationAgeThreshold = 3uintx StringTableSize = 65536bool SuperWordLoopUnrollAnalysis = truebool SuperWordReductions = truebool SuppressFatalErrorMessage = falseuintx SurvivorPadding = 3uintx SurvivorRatio = 8double SweeperThreshold = 0.500000uintx TLABAllocationWeight = 35uintx TLABRefillWasteFraction = 64size_t TLABSize = 0bool TLABStats = trueuintx TLABWasteIncrement = 4uintx TLABWasteTargetPercent = 1uintx TargetPLABWastePct = 10uintx TargetSurvivorRatio = 50uintx TenuredGenerationSizeIncrement = 20uintx TenuredGenerationSizeSupplement = 80uintx TenuredGenerationSizeSupplementDecay = 2intx ThreadPriorityPolicy = 0bool ThreadPriorityVerbose = falseintx ThreadStackSize = 0uintx ThresholdTolerance = 10intx Tier0BackedgeNotifyFreqLog = 10intx Tier0InvokeNotifyFreqLog = 7intx Tier0ProfilingStartPercentage = 200intx Tier23InlineeNotifyFreqLog = 20intx Tier2BackEdgeThreshold = 0intx Tier2BackedgeNotifyFreqLog = 14intx Tier2CompileThreshold = 0intx Tier2InvokeNotifyFreqLog = 11intx Tier3BackEdgeThreshold = 60000intx Tier3BackedgeNotifyFreqLog = 13intx Tier3CompileThreshold = 2000intx Tier3DelayOff = 2intx Tier3DelayOn = 5intx Tier3InvocationThreshold = 200intx Tier3InvokeNotifyFreqLog = 10intx Tier3LoadFeedback = 5intx Tier3MinInvocationThreshold = 100intx Tier4BackEdgeThreshold = 40000intx Tier4CompileThreshold = 15000intx Tier4InvocationThreshold = 5000intx Tier4LoadFeedback = 3intx Tier4MinInvocationThreshold = 600bool TieredCompilation = trueintx TieredCompileTaskTimeout = 50intx TieredRateUpdateMaxTime = 25intx TieredRateUpdateMinTime = 1intx TieredStopAtLevel = 4bool TimeLinearScan = falseccstr TraceJVMTI =intx TrackedInitializationLimit = 50bool TrapBasedNullChecks = falsebool TrapBasedRangeChecks = falseintx TypeProfileArgsLimit = 2uintx TypeProfileLevel = 111intx TypeProfileMajorReceiverPercent = 90intx TypeProfileParmsLimit = 2intx TypeProfileWidth = 2intx UnguardOnExecutionViolation = 0bool UseAES = trueintx UseAVX = 2bool UseAdaptiveGenerationSizePolicyAtMajorCollection = truebool UseAdaptiveGenerationSizePolicyAtMinorCollection = truebool UseAdaptiveNUMAChunkSizing = truebool UseAdaptiveSizeDecayMajorGCCost = truebool UseAdaptiveSizePolicy = truebool UseAdaptiveSizePolicyFootprintGoal = truebool UseAdaptiveSizePolicyWithSystemGC = falsebool UseAddressNop = truebool UseBASE64Intrinsics = falsebool UseBMI1Instructions = truebool UseBMI2Instructions = truebool UseBiasedLocking = falsebool UseBimorphicInlining = truebool UseCLMUL = truebool UseCMoveUnconditionally = falsebool UseCodeAging = truebool UseCodeCacheFlushing = truebool UseCompiler = truebool UseCompressedClassPointers = true {bool UseCompressedOops = true {bool UseCondCardMark = falsebool UseCountLeadingZerosInstruction = truebool UseCountTrailingZerosInstruction = truebool UseCountedLoopSafepoints = truebool UseCounterDecay = truebool UseDivMod = truebool UseDynamicNumberOfCompilerThreads = truebool UseDynamicNumberOfGCThreads = truebool UseEmptySlotsInSupers = truebool UseFMA = truebool UseFPUForSpilling = truebool UseFastJNIAccessors = truebool UseFastStosb = falsebool UseG1GC = truebool UseGCOverheadLimit = truebool UseHeavyMonitors = falsebool UseInlineCaches = truebool UseInterpreter = truebool UseJumpTables = truebool UseLargePages = falsebool UseLargePagesIndividualAllocation = falsebool UseLoopCounter = truebool UseLoopInvariantCodeMotion = truebool UseLoopPredicate = truebool UseMaximumCompactionOnSystemGC = truebool UseNUMA = falsebool UseNUMAInterleaving = falsebool UseNewLongLShift = truebool UseNotificationThread = truebool UseOSErrorReporting = falsebool UseOnStackReplacement = truebool UseOnlyInlinedBimorphic = truebool UseOptoBiasInlining = falsebool UsePSAdaptiveSurvivorSizePolicy = truebool UseParallelGC = falsebool UsePerfData = truebool UsePopCountInstruction = truebool UseProfiledLoopPredicate = truebool UseRTMDeopt = falsebool UseRTMLocking = falsebool UseSHA = trueintx UseSSE = 4bool UseSSE42Intrinsics = truebool UseSerialGC = falsebool UseSharedSpaces = truebool UseShenandoahGC = falsebool UseSignalChaining = truebool UseStoreImmI16 = truebool UseStringDeduplication = falsebool UseSubwordForMaxVector = truebool UseSuperWord = truebool UseTLAB = truebool UseThreadPriorities = truebool UseTypeProfile = truebool UseTypeSpeculation = truebool UseUnalignedLoadStores = truebool UseVectorCmov = falsebool UseXMMForArrayCopy = truebool UseXMMForObjInit = truebool UseXmmI2D = truebool UseXmmI2F = truebool UseXmmLoadAndClearUpper = truebool UseXmmRegToRegMoveAll = truebool UseZGC = falseintx VMThreadPriority = -1intx VMThreadStackSize = 0intx ValueMapInitialSize = 11intx ValueMapMaxLoopSize = 8intx ValueSearchLimit = 1000bool VerifySharedSpaces = falseuintx YoungGenerationSizeIncrement = 20uintx YoungGenerationSizeSupplement = 80uintx YoungGenerationSizeSupplementDecay = 8size_t YoungPLABSize = 4096double ZAllocationSpikeTolerance = 2.000000double ZCollectionInterval = 0.000000double ZFragmentationLimit = 25.000000size_t ZMarkStackSpaceLimit = 8589934592bool ZProactive = truebool ZUncommit = trueuintx ZUncommitDelay = 300bool ZeroTLAB = falseopenjdk version "17.0.6" 2023-01-17OpenJDK Runtime Environment Temurin-17.0.6+10 (build 17.0.6+10)OpenJDK 64-Bit Server VM Temurin-17.0.6+10 (build 17.0.6+10, mixed mode, sharing)