HotSpot JVM常用参数（选项）设置

╰半夏微凉° 2021-12-09 15:17 436阅读 0赞

**本文讨论的选项是针对HotSpot虚拟机的。**

# 1、选项分类及语法 #

HotspotJVM提供以下三大类选项：

## 1.1、标准选项 ##

这类选项的功能是很稳定的，在后续版本中也不太会发生变化。

运行java或者 java -help 可以看到所有的标准选项。

语法：所有的标准选项都是以 - 开头，比如-version，-server等。

## 1.2、X选项 ##

这类选项的功能还是很稳定，但官方的说法是它们的行为可能会在后续版本中改变，也有可能不在后续版本中提供了.

运行 java -X 命令可以看到所有的X选项。

语法：这类选项都是以 -X 开头，比如-Xms。

## 1.3、XX选项 ##

这类选项是属于实验性，主要是给JVM开发者用于开发和调试JVM的，在后续的版本中行为有可能会变化。

语法：

*  如果是布尔类型的选项，它的格式为-XX:+flag或者-XX:-flag，分别表示开启和关闭该选项。
 *  针对非布尔类型的选项，它的格式为-XX:flag=value

# 2、常用配置 #

## 2.1、指定JVM运行模式 ##

Hotspot JVM有两种类型，分别是server和client。

它们的区别是Server VM的初始堆空间会大一些，默认使用的是并行垃圾回收器，启动慢运行快。Client VM相对来讲会保守一些，初始堆空间会小一些，使用串行的垃圾回收器，它的目标是为了让JVM的启动速度更快，但运行速度会比Serverm模式慢些。

JVM在启动的时候会根据硬件和操作系统自动选择使用Server还是Client类型的JVM。

*  在32位Windows系统上，不论硬件配置如何，都默认使用Client类型的JVM。
 *  在其他32位操作系统上，如果机器配置有2GB以上的内存同时有2个以上的CPU，则默认会使用Server类型的JVM
 *  64位机器上只有Server类型的JVM。也就是说Client类型的JVM只在32位机器上提供。
 *  也可以使用-server和-client选项来指定JVM的类型，不过只在32位的机器上有效，原因见上面一条。

更多详细内容可参见：[http://docs.oracle.com/javase/7/docs/technotes/guides/vm/server-class.html][http_docs.oracle.com_javase_7_docs_technotes_guides_vm_server-class.html]

## 2.2、指定JIT编译器模式 ##

Java是一种解释型语言，但随着JIT技术的进步，它能在运行时将Java的字节码编译成本地代码。以下是几个相关的选项：

*  \-Xint表示禁用JIT，所有字节码都被解释执行，这个模式的速度最慢的。
 *  \-Xcomp表示所有字节码都首先被编译成本地代码，然后再执行。
 *  \-Xmixed，默认模式，让JIT根据程序运行的情况，有选择地将某些代码编译成本地代码。

\-Xcomp和-Xmixed到底谁的速度快，针对不同的程序可能有不同的结果，基本还是推荐用默认模式。

## 2.3、查看Java版本 ##

\-version和-showversion

\-version用于查看当前在使用什么版本的java及JRE、什么类型的JVM（Server/Client）、采用什么编译器模式。示例如下：

C:\Users\zsm>java -version
    java version "1.8.0_45"
    Java(TM) SE Runtime Environment (build 1.8.0_45-b14)
    Java HotSpot(TM) 64-Bit Server VM (build 25.45-b02, mixed mode)

\-showversion的作用是在运行一个程序时首先把上述信息打印出来，这样便于问题诊断。

建议Server类型的程序都把-showversion选项打开，这样可以发现一些配置问题，比如程序需要JDK1.7才能运行，而有的机器上装有多个JDK的版本，打开这个选项可以避免使用了错误版本的Java。

## 2.4、打印设置的XX选项及值 ##

有三个选项：-XX:+PrintCommandLineFlags、-XX:+PrintFlagsInitial、-XX:+PrintFlagsFinal

**-XX:+PrintCommandLineFlags：**与-showversion类似，此选项可以在程序运行时首先打印出用户手动设置或者JVM自动设置的XX选项，建议加上这个选项以辅助问题诊断。

如下示例显示了JVM自动配置的初始和最大的HeapSize以及其他的一些选项：

C:\Users\zsm>java -XX:+PrintCommandLineFlags -version
    -XX:InitialHeapSize=132712832 -XX:MaxHeapSize=2123405312 -XX:+PrintCommandLineFlags -XX:+UseCompressedClassPointers -XX:+UseCompressedOops -XX:-UseLargePagesIndividualAllocation -XX:+UseParallelGC
    java version "1.8.0_45"
    Java(TM) SE Runtime Environment (build 1.8.0_45-b14)
    Java HotSpot(TM) 64-Bit Server VM (build 25.45-b02, mixed mode)

**-XX:+PrintFlagsInitial：**表示打印出所有XX选项的默认值。示例如下：

![ContractedBlock.gif][] ![ExpandedBlockStart.gif][]

1 C:\Users\zsm>java -XX:+PrintFlagsInitial -version
      2 [Global flags]
      3     uintx AdaptiveSizeDecrementScaleFactor          = 4                                   {product}
      4     uintx AdaptiveSizeMajorGCDecayTimeScale         = 10                                  {product}
      5     uintx AdaptiveSizePausePolicy                   = 0                                   {product}
      6     uintx AdaptiveSizePolicyCollectionCostMargin    = 50                                  {product}
      7     uintx AdaptiveSizePolicyInitializingSteps       = 20                                  {product}
      8     uintx AdaptiveSizePolicyOutputInterval          = 0                                   {product}
      9     uintx AdaptiveSizePolicyWeight                  = 10                                  {product}
     10     uintx AdaptiveSizeThroughPutPolicy              = 0                                   {product}
     11     uintx AdaptiveTimeWeight                        = 25                                  {product}
     12      bool AdjustConcurrency                         = false                               {product}
     13      bool AggressiveOpts                            = false                               {product}
     14      intx AliasLevel                                = 3                                   {C2 product}
     15      bool AlignVector                               = true                                {C2 product}
     16      intx AllocateInstancePrefetchLines             = 1                                   {product}
     17      intx AllocatePrefetchDistance                  = -1                                  {product}
     18      intx AllocatePrefetchInstr                     = 0                                   {product}
     19      intx AllocatePrefetchLines                     = 3                                   {product}
     20      intx AllocatePrefetchStepSize                  = 16                                  {product}
     21      intx AllocatePrefetchStyle                     = 1                                   {product}
     22      bool AllowJNIEnvProxy                          = false                               {product}
     23      bool AllowNonVirtualCalls                      = false                               {product}
     24      bool AllowParallelDefineClass                  = false                               {product}
     25      bool AllowUserSignalHandlers                   = false                               {product}
     26      bool AlwaysActAsServerClassMachine             = false                               {product}
     27      bool AlwaysCompileLoopMethods                  = false                               {product}
     28      bool AlwaysLockClassLoader                     = false                               {product}
     29      bool AlwaysPreTouch                            = false                               {product}
     30      bool AlwaysRestoreFPU                          = false                               {product}
     31      bool AlwaysTenure                              = false                               {product}
     32      bool AssertOnSuspendWaitFailure                = false                               {product}
     33      bool AssumeMP                                  = false                               {product}
     34      intx AutoBoxCacheMax                           = 128                                 {C2 product}
     35     uintx AutoGCSelectPauseMillis                   = 5000                                {product}
     36      intx BCEATraceLevel                            = 0                                   {product}
     37      intx BackEdgeThreshold                         = 100000                              {pd product}
     38      bool BackgroundCompilation                     = true                                {pd product}
     39     uintx BaseFootPrintEstimate                     = 268435456                           {product}
     40      intx BiasedLockingBulkRebiasThreshold          = 20                                  {product}
     41      intx BiasedLockingBulkRevokeThreshold          = 40                                  {product}
     42      intx BiasedLockingDecayTime                    = 25000                               {product}
     43      intx BiasedLockingStartupDelay                 = 4000                                {product}
     44      bool BindGCTaskThreadsToCPUs                   = false                               {product}
     45      bool BlockLayoutByFrequency                    = true                                {C2 product}
     46      intx BlockLayoutMinDiamondPercentage           = 20                                  {C2 product}
     47      bool BlockLayoutRotateLoops                    = true                                {C2 product}
     48      bool BranchOnRegister                          = false                               {C2 product}
     49      bool BytecodeVerificationLocal                 = false                               {product}
     50      bool BytecodeVerificationRemote                = true                                {product}
     51      bool C1OptimizeVirtualCallProfiling            = true                                {C1 product}
     52      bool C1ProfileBranches                         = true                                {C1 product}
     53      bool C1ProfileCalls                            = true                                {C1 product}
     54      bool C1ProfileCheckcasts                       = true                                {C1 product}
     55      bool C1ProfileInlinedCalls                     = true                                {C1 product}
     56      bool C1ProfileVirtualCalls                     = true                                {C1 product}
     57      bool C1UpdateMethodData                        = true                                {C1 product}
     58      intx CICompilerCount                           = 2                                   {product}
     59      bool CICompilerCountPerCPU                     = false                               {product}
     60      bool CITime                                    = false                               {product}
     61      bool CMSAbortSemantics                         = false                               {product}
     62     uintx CMSAbortablePrecleanMinWorkPerIteration   = 100                                 {product}
     63      intx CMSAbortablePrecleanWaitMillis            = 100                                 {manageable}
     64     uintx CMSBitMapYieldQuantum                     = 10485760                            {product}
     65     uintx CMSBootstrapOccupancy                     = 50                                  {product}
     66      bool CMSClassUnloadingEnabled                  = true                                {product}
     67     uintx CMSClassUnloadingMaxInterval              = 0                                   {product}
     68      bool CMSCleanOnEnter                           = true                                {product}
     69      bool CMSCompactWhenClearAllSoftRefs            = true                                {product}
     70     uintx CMSConcMarkMultiple                       = 32                                  {product}
     71      bool CMSConcurrentMTEnabled                    = true                                {product}
     72     uintx CMSCoordinatorYieldSleepCount             = 10                                  {product}
     73      bool CMSDumpAtPromotionFailure                 = false                               {product}
     74      bool CMSEdenChunksRecordAlways                 = true                                {product}
     75     uintx CMSExpAvgFactor                           = 50                                  {product}
     76      bool CMSExtrapolateSweep                       = false                               {product}
     77     uintx CMSFullGCsBeforeCompaction                = 0                                   {product}
     78     uintx CMSIncrementalDutyCycle                   = 10                                  {product}
     79     uintx CMSIncrementalDutyCycleMin                = 0                                   {product}
     80      bool CMSIncrementalMode                        = false                               {product}
     81     uintx CMSIncrementalOffset                      = 0                                   {product}
     82      bool CMSIncrementalPacing                      = true                                {product}
     83     uintx CMSIncrementalSafetyFactor                = 10                                  {product}
     84     uintx CMSIndexedFreeListReplenish               = 4                                   {product}
     85      intx CMSInitiatingOccupancyFraction            = -1                                  {product}
     86     uintx CMSIsTooFullPercentage                    = 98                                  {product}
     87    double CMSLargeCoalSurplusPercent                = 0.950000                            {product}
     88    double CMSLargeSplitSurplusPercent               = 1.000000                            {product}
     89      bool CMSLoopWarn                               = false                               {product}
     90     uintx CMSMaxAbortablePrecleanLoops              = 0                                   {product}
     91      intx CMSMaxAbortablePrecleanTime               = 5000                                {product}
     92     uintx CMSOldPLABMax                             = 1024                                {product}
     93     uintx CMSOldPLABMin                             = 16                                  {product}
     94     uintx CMSOldPLABNumRefills                      = 4                                   {product}
     95     uintx CMSOldPLABReactivityFactor                = 2                                   {product}
     96      bool CMSOldPLABResizeQuicker                   = false                               {product}
     97     uintx CMSOldPLABToleranceFactor                 = 4                                   {product}
     98      bool CMSPLABRecordAlways                       = true                                {product}
     99     uintx CMSParPromoteBlocksToClaim                = 16                                  {product}
    100      bool CMSParallelInitialMarkEnabled             = true                                {product}
    101      bool CMSParallelRemarkEnabled                  = true                                {product}
    102      bool CMSParallelSurvivorRemarkEnabled          = true                                {product}
    103     uintx CMSPrecleanDenominator                    = 3                                   {product}
    104     uintx CMSPrecleanIter                           = 3                                   {product}
    105     uintx CMSPrecleanNumerator                      = 2                                   {product}
    106      bool CMSPrecleanRefLists1                      = true                                {product}
    107      bool CMSPrecleanRefLists2                      = false                               {product}
    108      bool CMSPrecleanSurvivors1                     = false                               {product}
    109      bool CMSPrecleanSurvivors2                     = true                                {product}
    110     uintx CMSPrecleanThreshold                      = 1000                                {product}
    111      bool CMSPrecleaningEnabled                     = true                                {product}
    112      bool CMSPrintChunksInDump                      = false                               {product}
    113      bool CMSPrintEdenSurvivorChunks                = false                               {product}
    114      bool CMSPrintObjectsInDump                     = false                               {product}
    115     uintx CMSRemarkVerifyVariant                    = 1                                   {product}
    116      bool CMSReplenishIntermediate                  = true                                {product}
    117     uintx CMSRescanMultiple                         = 32                                  {product}
    118     uintx CMSSamplingGrain                          = 16384                               {product}
    119      bool CMSScavengeBeforeRemark                   = false                               {product}
    120     uintx CMSScheduleRemarkEdenPenetration          = 50                                  {product}
    121     uintx CMSScheduleRemarkEdenSizeThreshold        = 2097152                             {product}
    122     uintx CMSScheduleRemarkSamplingRatio            = 5                                   {product}
    123    double CMSSmallCoalSurplusPercent                = 1.050000                            {product}
    124    double CMSSmallSplitSurplusPercent               = 1.100000                            {product}
    125      bool CMSSplitIndexedFreeListBlocks             = true                                {product}
    126      intx CMSTriggerInterval                        = -1                                  {manageable}
    127     uintx CMSTriggerRatio                           = 80                                  {product}
    128      intx CMSWaitDuration                           = 2000                                {manageable}
    129     uintx CMSWorkQueueDrainThreshold                = 10                                  {product}
    130      bool CMSYield                                  = true                                {product}
    131     uintx CMSYieldSleepCount                        = 0                                   {product}
    132     uintx CMSYoungGenPerWorker                      = 67108864                            {pd product}
    133     uintx CMS_FLSPadding                            = 1                                   {product}
    134     uintx CMS_FLSWeight                             = 75                                  {product}
    135     uintx CMS_SweepPadding                          = 1                                   {product}
    136     uintx CMS_SweepTimerThresholdMillis             = 10                                  {product}
    137     uintx CMS_SweepWeight                           = 75                                  {product}
    138      bool CheckEndorsedAndExtDirs                   = false                               {product}
    139      bool CheckJNICalls                             = false                               {product}
    140      bool ClassUnloading                            = true                                {product}
    141      bool ClassUnloadingWithConcurrentMark          = true                                {product}
    142      intx ClearFPUAtPark                            = 0                                   {product}
    143      bool ClipInlining                              = true                                {product}
    144     uintx CodeCacheExpansionSize                    = 65536                               {pd product}
    145     uintx CodeCacheMinimumFreeSpace                 = 512000                              {product}
    146      bool CollectGen0First                          = false                               {product}
    147      bool CompactFields                             = true                                {product}
    148      intx CompilationPolicyChoice                   = 0                                   {product}
    149 ccstrlist CompileCommand                            =                                     {product}
    150     ccstr CompileCommandFile                        =                                     {product}
    151 ccstrlist CompileOnly                               =                                     {product}
    152      intx CompileThreshold                          = 10000                               {pd product}
    153      bool CompilerThreadHintNoPreempt               = true                                {product}
    154      intx CompilerThreadPriority                    = -1                                  {product}
    155      intx CompilerThreadStackSize                   = 0                                   {pd product}
    156     uintx CompressedClassSpaceSize                  = 1073741824                          {product}
    157     uintx ConcGCThreads                             = 0                                   {product}
    158      intx ConditionalMoveLimit                      = 3                                   {C2 pd product}
    159      intx ContendedPaddingWidth                     = 128                                 {product}
    160      bool ConvertSleepToYield                       = true                                {pd product}
    161      bool ConvertYieldToSleep                       = false                               {product}
    162      bool CreateMinidumpOnCrash                     = false                               {product}
    163      bool CriticalJNINatives                        = true                                {product}
    164      bool DTraceAllocProbes                         = false                               {product}
    165      bool DTraceMethodProbes                        = false                               {product}
    166      bool DTraceMonitorProbes                       = false                               {product}
    167      bool Debugging                                 = false                               {product}
    168     uintx DefaultMaxRAMFraction                     = 4                                   {product}
    169      intx DefaultThreadPriority                     = -1                                  {product}
    170      intx DeferPollingPageLoopCount                 = -1                                  {product}
    171      intx DeferThrSuspendLoopCount                  = 4000                                {product}
    172      bool DeoptimizeRandom                          = false                               {product}
    173      bool DisableAttachMechanism                    = false                               {product}
    174      bool DisableExplicitGC                         = false                               {product}
    175      bool DisplayVMOutputToStderr                   = false                               {product}
    176      bool DisplayVMOutputToStdout                   = false                               {product}
    177      bool DoEscapeAnalysis                          = true                                {C2 product}
    178      bool DontCompileHugeMethods                    = true                                {product}
    179      bool DontYieldALot                             = false                               {pd product}
    180     ccstr DumpLoadedClassList                       =                                     {product}
    181      bool DumpReplayDataOnError                     = true                                {product}
    182      bool DumpSharedSpaces                          = false                               {product}
    183      bool EagerXrunInit                             = false                               {product}
    184      intx EliminateAllocationArraySizeLimit         = 64                                  {C2 product}
    185      bool EliminateAllocations                      = true                                {C2 product}
    186      bool EliminateAutoBox                          = true                                {C2 product}
    187      bool EliminateLocks                            = true                                {C2 product}
    188      bool EliminateNestedLocks                      = true                                {C2 product}
    189      intx EmitSync                                  = 0                                   {product}
    190      bool EnableContended                           = true                                {product}
    191      bool EnableSharedLookupCache                   = true                                {product}
    192      bool EnableTracing                             = false                               {product}
    193     uintx ErgoHeapSizeLimit                         = 0                                   {product}
    194     ccstr ErrorFile                                 =                                     {product}
    195     ccstr ErrorReportServer                         =                                     {product}
    196    double EscapeAnalysisTimeout                     = 20.000000                           {C2 product}
    197      bool EstimateArgEscape                         = true                                {product}
    198      bool ExplicitGCInvokesConcurrent               = false                               {product}
    199      bool ExplicitGCInvokesConcurrentAndUnloadsClasses  = false                               {product}
    200      bool ExtendedDTraceProbes                      = false                               {product}
    201     ccstr ExtraSharedClassListFile                  =                                     {product}
    202      bool FLSAlwaysCoalesceLarge                    = false                               {product}
    203     uintx FLSCoalescePolicy                         = 2                                   {product}
    204    double FLSLargestBlockCoalesceProximity          = 0.990000                            {product}
    205      bool FailOverToOldVerifier                     = true                                {product}
    206      bool FastTLABRefill                            = true                                {product}
    207      intx FenceInstruction                          = 0                                   {ARCH product}
    208      intx FieldsAllocationStyle                     = 1                                   {product}
    209      bool FilterSpuriousWakeups                     = true                                {product}
    210     ccstr FlightRecorderOptions                     =                                     {product}
    211      bool ForceNUMA                                 = false                               {product}
    212      bool ForceTimeHighResolution                   = false                               {product}
    213      intx FreqInlineSize                            = 325                                 {pd product}
    214    double G1ConcMarkStepDurationMillis              = 10.000000                           {product}
    215     uintx G1ConcRSHotCardLimit                      = 4                                   {product}
    216     uintx G1ConcRSLogCacheSize                      = 10                                  {product}
    217      intx G1ConcRefinementGreenZone                 = 0                                   {product}
    218      intx G1ConcRefinementRedZone                   = 0                                   {product}
    219      intx G1ConcRefinementServiceIntervalMillis     = 300                                 {product}
    220     uintx G1ConcRefinementThreads                   = 0                                   {product}
    221      intx G1ConcRefinementThresholdStep             = 0                                   {product}
    222      intx G1ConcRefinementYellowZone                = 0                                   {product}
    223     uintx G1ConfidencePercent                       = 50                                  {product}
    224     uintx G1HeapRegionSize                          = 0                                   {product}
    225     uintx G1HeapWastePercent                        = 5                                   {product}
    226     uintx G1MixedGCCountTarget                      = 8                                   {product}
    227      intx G1RSetRegionEntries                       = 0                                   {product}
    228     uintx G1RSetScanBlockSize                       = 64                                  {product}
    229      intx G1RSetSparseRegionEntries                 = 0                                   {product}
    230      intx G1RSetUpdatingPauseTimePercent            = 10                                  {product}
    231      intx G1RefProcDrainInterval                    = 10                                  {product}
    232     uintx G1ReservePercent                          = 10                                  {product}
    233     uintx G1SATBBufferEnqueueingThresholdPercent    = 60                                  {product}
    234      intx G1SATBBufferSize                          = 1024                                {product}
    235      intx G1UpdateBufferSize                        = 256                                 {product}
    236      bool G1UseAdaptiveConcRefinement               = true                                {product}
    237     uintx GCDrainStackTargetSize                    = 64                                  {product}
    238     uintx GCHeapFreeLimit                           = 2                                   {product}
    239     uintx GCLockerEdenExpansionPercent              = 5                                   {product}
    240      bool GCLockerInvokesConcurrent                 = false                               {product}
    241     uintx GCLogFileSize                             = 8192                                {product}
    242     uintx GCPauseIntervalMillis                     = 0                                   {product}
    243     uintx GCTaskTimeStampEntries                    = 200                                 {product}
    244     uintx GCTimeLimit                               = 98                                  {product}
    245     uintx GCTimeRatio                               = 99                                  {product}
    246     uintx HeapBaseMinAddress                        = 2147483648                          {pd product}
    247      bool HeapDumpAfterFullGC                       = false                               {manageable}
    248      bool HeapDumpBeforeFullGC                      = false                               {manageable}
    249      bool HeapDumpOnOutOfMemoryError                = false                               {manageable}
    250     ccstr HeapDumpPath                              =                                     {manageable}
    251     uintx HeapFirstMaximumCompactionCount           = 3                                   {product}
    252     uintx HeapMaximumCompactionInterval             = 20                                  {product}
    253     uintx HeapSizePerGCThread                       = 87241520                            {product}
    254      bool IgnoreEmptyClassPaths                     = false                               {product}
    255      bool IgnoreUnrecognizedVMOptions               = false                               {product}
    256     uintx IncreaseFirstTierCompileThresholdAt       = 50                                  {product}
    257      bool IncrementalInline                         = true                                {C2 product}
    258     uintx InitialBootClassLoaderMetaspaceSize       = 4194304                             {product}
    259     uintx InitialCodeCacheSize                      = 2555904                             {pd product}
    260     uintx InitialHeapSize                           = 0                                   {product}
    261     uintx InitialRAMFraction                        = 64                                  {product}
    262     uintx InitialSurvivorRatio                      = 8                                   {product}
    263     uintx InitialTenuringThreshold                  = 7                                   {product}
    264     uintx InitiatingHeapOccupancyPercent            = 45                                  {product}
    265      bool Inline                                    = true                                {product}
    266     ccstr InlineDataFile                            =                                     {product}
    267      intx InlineSmallCode                           = 1000                                {pd product}
    268      bool InlineSynchronizedMethods                 = true                                {C1 product}
    269      bool InsertMemBarAfterArraycopy                = true                                {C2 product}
    270      intx InteriorEntryAlignment                    = 16                                  {C2 pd product}
    271      intx InterpreterProfilePercentage              = 33                                  {product}
    272      bool JNIDetachReleasesMonitors                 = true                                {product}
    273      bool JavaMonitorsInStackTrace                  = true                                {product}
    274      intx JavaPriority10_To_OSPriority              = -1                                  {product}
    275      intx JavaPriority1_To_OSPriority               = -1                                  {product}
    276      intx JavaPriority2_To_OSPriority               = -1                                  {product}
    277      intx JavaPriority3_To_OSPriority               = -1                                  {product}
    278      intx JavaPriority4_To_OSPriority               = -1                                  {product}
    279      intx JavaPriority5_To_OSPriority               = -1                                  {product}
    280      intx JavaPriority6_To_OSPriority               = -1                                  {product}
    281      intx JavaPriority7_To_OSPriority               = -1                                  {product}
    282      intx JavaPriority8_To_OSPriority               = -1                                  {product}
    283      intx JavaPriority9_To_OSPriority               = -1                                  {product}
    284      bool LIRFillDelaySlots                         = false                               {C1 pd product}
    285     uintx LargePageHeapSizeThreshold                = 134217728                           {product}
    286     uintx LargePageSizeInBytes                      = 0                                   {product}
    287      bool LazyBootClassLoader                       = true                                {product}
    288      intx LiveNodeCountInliningCutoff               = 40000                               {C2 product}
    289      bool LogCommercialFeatures                     = false                               {product}
    290      intx LoopMaxUnroll                             = 16                                  {C2 product}
    291      intx LoopOptsCount                             = 43                                  {C2 product}
    292      intx LoopUnrollLimit                           = 60                                  {C2 pd product}
    293      intx LoopUnrollMin                             = 4                                   {C2 product}
    294      bool LoopUnswitching                           = true                                {C2 product}
    295      bool ManagementServer                          = false                               {product}
    296     uintx MarkStackSize                             = 4194304                             {product}
    297     uintx MarkStackSizeMax                          = 536870912                           {product}
    298     uintx MarkSweepAlwaysCompactCount               = 4                                   {product}
    299     uintx MarkSweepDeadRatio                        = 5                                   {product}
    300      intx MaxBCEAEstimateLevel                      = 5                                   {product}
    301      intx MaxBCEAEstimateSize                       = 150                                 {product}
    302     uintx MaxDirectMemorySize                       = 0                                   {product}
    303      bool MaxFDLimit                                = true                                {product}
    304     uintx MaxGCMinorPauseMillis                     = 4294967295                          {product}
    305     uintx MaxGCPauseMillis                          = 4294967295                          {product}
    306     uintx MaxHeapFreeRatio                          = 70                                  {manageable}
    307     uintx MaxHeapSize                               = 130862280                           {product}
    308      intx MaxInlineLevel                            = 9                                   {product}
    309      intx MaxInlineSize                             = 35                                  {product}
    310      intx MaxJNILocalCapacity                       = 65536                               {product}
    311      intx MaxJavaStackTraceDepth                    = 1024                                {product}
    312      intx MaxJumpTableSize                          = 65000                               {C2 product}
    313      intx MaxJumpTableSparseness                    = 5                                   {C2 product}
    314      intx MaxLabelRootDepth                         = 1100                                {C2 product}
    315      intx MaxLoopPad                                = 15                                  {C2 product}
    316     uintx MaxMetaspaceExpansion                     = 5452592                             {product}
    317     uintx MaxMetaspaceFreeRatio                     = 70                                  {product}
    318     uintx MaxMetaspaceSize                          = 4294967295                          {product}
    319     uintx MaxNewSize                                = 4294967295                          {product}
    320      intx MaxNodeLimit                              = 80000                               {C2 product}
    321  uint64_t MaxRAM                                    = 0                                   {pd product}
    322     uintx MaxRAMFraction                            = 4                                   {product}
    323      intx MaxRecursiveInlineLevel                   = 1                                   {product}
    324     uintx MaxTenuringThreshold                      = 15                                  {product}
    325      intx MaxTrivialSize                            = 6                                   {product}
    326      intx MaxVectorSize                             = 32                                  {C2 product}
    327     uintx MetaspaceSize                             = 21810376                            {pd product}
    328      bool MethodFlushing                            = true                                {product}
    329     uintx MinHeapDeltaBytes                         = 170392                              {product}
    330     uintx MinHeapFreeRatio                          = 40                                  {manageable}
    331      intx MinInliningThreshold                      = 250                                 {product}
    332      intx MinJumpTableSize                          = 10                                  {C2 pd product}
    333     uintx MinMetaspaceExpansion                     = 340784                              {product}
    334     uintx MinMetaspaceFreeRatio                     = 40                                  {product}
    335     uintx MinRAMFraction                            = 2                                   {product}
    336     uintx MinSurvivorRatio                          = 3                                   {product}
    337     uintx MinTLABSize                               = 2048                                {product}
    338      intx MonitorBound                              = 0                                   {product}
    339      bool MonitorInUseLists                         = false                               {product}
    340      intx MultiArrayExpandLimit                     = 6                                   {C2 product}
    341      bool MustCallLoadClassInternal                 = false                               {product}
    342     uintx NUMAChunkResizeWeight                     = 20                                  {product}
    343     uintx NUMAInterleaveGranularity                 = 2097152                             {product}
    344     uintx NUMAPageScanRate                          = 256                                 {product}
    345     uintx NUMASpaceResizeRate                       = 1073741824                          {product}
    346      bool NUMAStats                                 = false                               {product}
    347     ccstr NativeMemoryTracking                      = off                                 {product}
    348      bool NeedsDeoptSuspend                         = false                               {pd product}
    349      bool NeverActAsServerClassMachine              = false                               {pd product}
    350      bool NeverTenure                               = false                               {product}
    351     uintx NewRatio                                  = 2                                   {product}
    352     uintx NewSize                                   = 1363144                             {product}
    353     uintx NewSizeThreadIncrease                     = 5320                                {pd product}
    354      intx NmethodSweepActivity                      = 10                                  {product}
    355      intx NmethodSweepCheckInterval                 = 5                                   {product}
    356      intx NmethodSweepFraction                      = 16                                  {product}
    357      intx NodeLimitFudgeFactor                      = 2000                                {C2 product}
    358     uintx NumberOfGCLogFiles                        = 0                                   {product}
    359      intx NumberOfLoopInstrToAlign                  = 4                                   {C2 product}
    360      intx ObjectAlignmentInBytes                    = 8                                   {lp64_product}
    361     uintx OldPLABSize                               = 1024                                {product}
    362     uintx OldPLABWeight                             = 50                                  {product}
    363     uintx OldSize                                   = 5452592                             {product}
    364      bool OmitStackTraceInFastThrow                 = true                                {product}
    365 ccstrlist OnError                                   =                                     {product}
    366 ccstrlist OnOutOfMemoryError                        =                                     {product}
    367      intx OnStackReplacePercentage                  = 140                                 {pd product}
    368      bool OptimizeFill                              = true                                {C2 product}
    369      bool OptimizePtrCompare                        = true                                {C2 product}
    370      bool OptimizeStringConcat                      = true                                {C2 product}
    371      bool OptoBundling                              = false                               {C2 pd product}
    372      intx OptoLoopAlignment                         = 16                                  {pd product}
    373      bool OptoScheduling                            = false                               {C2 pd product}
    374     uintx PLABWeight                                = 75                                  {product}
    375      bool PSChunkLargeArrays                        = true                                {product}
    376      intx ParGCArrayScanChunk                       = 50                                  {product}
    377     uintx ParGCDesiredObjsFromOverflowList          = 20                                  {product}
    378      bool ParGCTrimOverflow                         = true                                {product}
    379      bool ParGCUseLocalOverflow                     = false                               {product}
    380     uintx ParallelGCBufferWastePct                  = 10                                  {product}
    381     uintx ParallelGCThreads                         = 0                                   {product}
    382      bool ParallelGCVerbose                         = false                               {product}
    383     uintx ParallelOldDeadWoodLimiterMean            = 50                                  {product}
    384     uintx ParallelOldDeadWoodLimiterStdDev          = 80                                  {product}
    385      bool ParallelRefProcBalancingEnabled           = true                                {product}
    386      bool ParallelRefProcEnabled                    = false                               {product}
    387      bool PartialPeelAtUnsignedTests                = true                                {C2 product}
    388      bool PartialPeelLoop                           = true                                {C2 product}
    389      intx PartialPeelNewPhiDelta                    = 0                                   {C2 product}
    390     uintx PausePadding                              = 1                                   {product}
    391      intx PerBytecodeRecompilationCutoff            = 200                                 {product}
    392      intx PerBytecodeTrapLimit                      = 4                                   {product}
    393      intx PerMethodRecompilationCutoff              = 400                                 {product}
    394      intx PerMethodTrapLimit                        = 100                                 {product}
    395      bool PerfAllowAtExitRegistration               = false                               {product}
    396      bool PerfBypassFileSystemCheck                 = false                               {product}
    397      intx PerfDataMemorySize                        = 32768                               {product}
    398      intx PerfDataSamplingInterval                  = 50                                  {product}
    399     ccstr PerfDataSaveFile                          =                                     {product}
    400      bool PerfDataSaveToFile                        = false                               {product}
    401      bool PerfDisableSharedMem                      = false                               {product}
    402      intx PerfMaxStringConstLength                  = 1024                                {product}
    403      intx PreInflateSpin                            = 10                                  {pd product}
    404      bool PreferInterpreterNativeStubs              = false                               {pd product}
    405      intx PrefetchCopyIntervalInBytes               = -1                                  {product}
    406      intx PrefetchFieldsAhead                       = -1                                  {product}
    407      intx PrefetchScanIntervalInBytes               = -1                                  {product}
    408      bool PreserveAllAnnotations                    = false                               {product}
    409     uintx PretenureSizeThreshold                    = 0                                   {product}
    410      bool PrintAdaptiveSizePolicy                   = false                               {product}
    411      bool PrintCMSInitiationStatistics              = false                               {product}
    412      intx PrintCMSStatistics                        = 0                                   {product}
    413      bool PrintClassHistogram                       = false                               {manageable}
    414      bool PrintClassHistogramAfterFullGC            = false                               {manageable}
    415      bool PrintClassHistogramBeforeFullGC           = false                               {manageable}
    416      bool PrintCodeCache                            = false                               {product}
    417      bool PrintCodeCacheOnCompilation               = false                               {product}
    418      bool PrintCommandLineFlags                     = false                               {product}
    419      bool PrintCompilation                          = false                               {product}
    420      bool PrintConcurrentLocks                      = false                               {manageable}
    421      intx PrintFLSCensus                            = 0                                   {product}
    422      intx PrintFLSStatistics                        = 0                                   {product}
    423      bool PrintFlagsFinal                           = false                               {product}
    424      bool PrintFlagsInitial                         = false                               {product}
    425      bool PrintGC                                   = false                               {manageable}
    426      bool PrintGCApplicationConcurrentTime          = false                               {product}
    427      bool PrintGCApplicationStoppedTime             = false                               {product}
    428      bool PrintGCCause                              = true                                {product}
    429      bool PrintGCDateStamps                         = false                               {manageable}
    430      bool PrintGCDetails                            = false                               {manageable}
    431      bool PrintGCID                                 = false                               {manageable}
    432      bool PrintGCTaskTimeStamps                     = false                               {product}
    433      bool PrintGCTimeStamps                         = false                               {manageable}
    434      bool PrintHeapAtGC                             = false                               {product rw}
    435      bool PrintHeapAtGCExtended                     = false                               {product rw}
    436      bool PrintHeapAtSIGBREAK                       = true                                {product}
    437      bool PrintJNIGCStalls                          = false                               {product}
    438      bool PrintJNIResolving                         = false                               {product}
    439      bool PrintOldPLAB                              = false                               {product}
    440      bool PrintOopAddress                           = false                               {product}
    441      bool PrintPLAB                                 = false                               {product}
    442      bool PrintParallelOldGCPhaseTimes              = false                               {product}
    443      bool PrintPromotionFailure                     = false                               {product}
    444      bool PrintReferenceGC                          = false                               {product}
    445      bool PrintSafepointStatistics                  = false                               {product}
    446      intx PrintSafepointStatisticsCount             = 300                                 {product}
    447      intx PrintSafepointStatisticsTimeout           = -1                                  {product}
    448      bool PrintSharedArchiveAndExit                 = false                               {product}
    449      bool PrintSharedDictionary                     = false                               {product}
    450      bool PrintSharedSpaces                         = false                               {product}
    451      bool PrintStringDeduplicationStatistics        = false                               {product}
    452      bool PrintStringTableStatistics                = false                               {product}
    453      bool PrintTLAB                                 = false                               {product}
    454      bool PrintTenuringDistribution                 = false                               {product}
    455      bool PrintTieredEvents                         = false                               {product}
    456      bool PrintVMOptions                            = false                               {product}
    457      bool PrintVMQWaitTime                          = false                               {product}
    458      bool PrintWarnings                             = true                                {product}
    459     uintx ProcessDistributionStride                 = 4                                   {product}
    460      bool ProfileInterpreter                        = true                                {pd product}
    461      bool ProfileIntervals                          = false                               {product}
    462      intx ProfileIntervalsTicks                     = 100                                 {product}
    463      intx ProfileMaturityPercentage                 = 20                                  {product}
    464      bool ProfileVM                                 = false                               {product}
    465      bool ProfilerPrintByteCodeStatistics           = false                               {product}
    466      bool ProfilerRecordPC                          = false                               {product}
    467     uintx PromotedPadding                           = 3                                   {product}
    468     uintx QueuedAllocationWarningCount              = 0                                   {product}
    469     uintx RTMRetryCount                             = 5                                   {ARCH product}
    470      bool RangeCheckElimination                     = true                                {product}
    471      intx ReadPrefetchInstr                         = 0                                   {ARCH product}
    472      bool ReassociateInvariants                     = true                                {C2 product}
    473      bool ReduceBulkZeroing                         = true                                {C2 product}
    474      bool ReduceFieldZeroing                        = true                                {C2 product}
    475      bool ReduceInitialCardMarks                    = true                                {C2 product}
    476      bool ReduceSignalUsage                         = false                               {product}
    477      intx RefDiscoveryPolicy                        = 0                                   {product}
    478      bool ReflectionWrapResolutionErrors            = true                                {product}
    479      bool RegisterFinalizersAtInit                  = true                                {product}
    480      bool RelaxAccessControlCheck                   = false                               {product}
    481     ccstr ReplayDataFile                            =                                     {product}
    482      bool RequireSharedSpaces                       = false                               {product}
    483     uintx ReservedCodeCacheSize                     = 50331648                            {pd product}
    484      bool ResizeOldPLAB                             = true                                {product}
    485      bool ResizePLAB                                = true                                {product}
    486      bool ResizeTLAB                                = true                                {pd product}
    487      bool RestoreMXCSROnJNICalls                    = false                               {product}
    488      bool RestrictContended                         = true                                {product}
    489      bool RewriteBytecodes                          = true                                {pd product}
    490      bool RewriteFrequentPairs                      = true                                {pd product}
    491      intx SafepointPollOffset                       = 256                                 {C1 pd product}
    492      intx SafepointSpinBeforeYield                  = 2000                                {product}
    493      bool SafepointTimeout                          = false                               {product}
    494      intx SafepointTimeoutDelay                     = 10000                               {product}
    495      bool ScavengeBeforeFullGC                      = true                                {product}
    496      intx SelfDestructTimer                         = 0                                   {product}
    497     uintx SharedBaseAddress                         = 0                                   {product}
    498     ccstr SharedClassListFile                       =                                     {product}
    499     uintx SharedMiscCodeSize                        = 122880                              {product}
    500     uintx SharedMiscDataSize                        = 4194304                             {product}
    501     uintx SharedReadOnlySize                        = 16777216                            {product}
    502     uintx SharedReadWriteSize                       = 16777216                            {product}
    503      bool ShowMessageBoxOnError                     = false                               {product}
    504      intx SoftRefLRUPolicyMSPerMB                   = 1000                                {product}
    505      bool SpecialEncodeISOArray                     = true                                {C2 product}
    506      bool SplitIfBlocks                             = true                                {C2 product}
    507      intx StackRedPages                             = 1                                   {pd product}
    508      intx StackShadowPages                          = 6                                   {pd product}
    509      bool StackTraceInThrowable                     = true                                {product}
    510      intx StackYellowPages                          = 3                                   {pd product}
    511      bool StartAttachListener                       = false                               {product}
    512      intx StarvationMonitorInterval                 = 200                                 {product}
    513      bool StressLdcRewrite                          = false                               {product}
    514     uintx StringDeduplicationAgeThreshold           = 3                                   {product}
    515     uintx StringTableSize                           = 60013                               {product}
    516      bool SuppressFatalErrorMessage                 = false                               {product}
    517     uintx SurvivorPadding                           = 3                                   {product}
    518     uintx SurvivorRatio                             = 8                                   {product}
    519      intx SuspendRetryCount                         = 50                                  {product}
    520      intx SuspendRetryDelay                         = 5                                   {product}
    521      intx SyncFlags                                 = 0                                   {product}
    522     ccstr SyncKnobs                                 =                                     {product}
    523      intx SyncVerbose                               = 0                                   {product}
    524     uintx TLABAllocationWeight                      = 35                                  {product}
    525     uintx TLABRefillWasteFraction                   = 64                                  {product}
    526     uintx TLABSize                                  = 0                                   {product}
    527      bool TLABStats                                 = true                                {product}
    528     uintx TLABWasteIncrement                        = 4                                   {product}
    529     uintx TLABWasteTargetPercent                    = 1                                   {product}
    530     uintx TargetPLABWastePct                        = 10                                  {product}
    531     uintx TargetSurvivorRatio                       = 50                                  {product}
    532     uintx TenuredGenerationSizeIncrement            = 20                                  {product}
    533     uintx TenuredGenerationSizeSupplement           = 80                                  {product}
    534     uintx TenuredGenerationSizeSupplementDecay      = 2                                   {product}
    535      intx ThreadPriorityPolicy                      = 0                                   {product}
    536      bool ThreadPriorityVerbose                     = false                               {product}
    537     uintx ThreadSafetyMargin                        = 52428800                            {product}
    538      intx ThreadStackSize                           = 0                                   {pd product}
    539     uintx ThresholdTolerance                        = 10                                  {product}
    540      intx Tier0BackedgeNotifyFreqLog                = 10                                  {product}
    541      intx Tier0InvokeNotifyFreqLog                  = 7                                   {product}
    542      intx Tier0ProfilingStartPercentage             = 200                                 {product}
    543      intx Tier23InlineeNotifyFreqLog                = 20                                  {product}
    544      intx Tier2BackEdgeThreshold                    = 0                                   {product}
    545      intx Tier2BackedgeNotifyFreqLog                = 14                                  {product}
    546      intx Tier2CompileThreshold                     = 0                                   {product}
    547      intx Tier2InvokeNotifyFreqLog                  = 11                                  {product}
    548      intx Tier3BackEdgeThreshold                    = 60000                               {product}
    549      intx Tier3BackedgeNotifyFreqLog                = 13                                  {product}
    550      intx Tier3CompileThreshold                     = 2000                                {product}
    551      intx Tier3DelayOff                             = 2                                   {product}
    552      intx Tier3DelayOn                              = 5                                   {product}
    553      intx Tier3InvocationThreshold                  = 200                                 {product}
    554      intx Tier3InvokeNotifyFreqLog                  = 10                                  {product}
    555      intx Tier3LoadFeedback                         = 5                                   {product}
    556      intx Tier3MinInvocationThreshold               = 100                                 {product}
    557      intx Tier4BackEdgeThreshold                    = 40000                               {product}
    558      intx Tier4CompileThreshold                     = 15000                               {product}
    559      intx Tier4InvocationThreshold                  = 5000                                {product}
    560      intx Tier4LoadFeedback                         = 3                                   {product}
    561      intx Tier4MinInvocationThreshold               = 600                                 {product}
    562      bool TieredCompilation                         = true                                {pd product}
    563      intx TieredCompileTaskTimeout                  = 50                                  {product}
    564      intx TieredRateUpdateMaxTime                   = 25                                  {product}
    565      intx TieredRateUpdateMinTime                   = 1                                   {product}
    566      intx TieredStopAtLevel                         = 4                                   {product}
    567      bool TimeLinearScan                            = false                               {C1 product}
    568      bool TraceBiasedLocking                        = false                               {product}
    569      bool TraceClassLoading                         = false                               {product rw}
    570      bool TraceClassLoadingPreorder                 = false                               {product}
    571      bool TraceClassPaths                           = false                               {product}
    572      bool TraceClassResolution                      = false                               {product}
    573      bool TraceClassUnloading                       = false                               {product rw}
    574      bool TraceDynamicGCThreads                     = false                               {product}
    575      bool TraceGen0Time                             = false                               {product}
    576      bool TraceGen1Time                             = false                               {product}
    577     ccstr TraceJVMTI                                =                                     {product}
    578      bool TraceLoaderConstraints                    = false                               {product rw}
    579      bool TraceMetadataHumongousAllocation          = false                               {product}
    580      bool TraceMonitorInflation                     = false                               {product}
    581      bool TraceParallelOldGCTasks                   = false                               {product}
    582      intx TraceRedefineClasses                      = 0                                   {product}
    583      bool TraceSafepointCleanupTime                 = false                               {product}
    584      bool TraceSharedLookupCache                    = false                               {product}
    585      bool TraceSuspendWaitFailures                  = false                               {product}
    586      intx TrackedInitializationLimit                = 50                                  {C2 product}
    587      bool TransmitErrorReport                       = false                               {product}
    588      bool TrapBasedNullChecks                       = false                               {pd product}
    589      bool TrapBasedRangeChecks                      = false                               {C2 pd product}
    590      intx TypeProfileArgsLimit                      = 2                                   {product}
    591     uintx TypeProfileLevel                          = 111                                 {pd product}
    592      intx TypeProfileMajorReceiverPercent           = 90                                  {C2 product}
    593      intx TypeProfileParmsLimit                     = 2                                   {product}
    594      intx TypeProfileWidth                          = 2                                   {product}
    595      intx UnguardOnExecutionViolation               = 0                                   {product}
    596      bool UnlinkSymbolsALot                         = false                               {product}
    597      bool Use486InstrsOnly                          = false                               {ARCH product}
    598      bool UseAES                                    = false                               {product}
    599      bool UseAESIntrinsics                          = false                               {product}
    600      intx UseAVX                                    = 99                                  {ARCH product}
    601      bool UseAdaptiveGCBoundary                     = false                               {product}
    602      bool UseAdaptiveGenerationSizePolicyAtMajorCollection  = true                                {product}
    603      bool UseAdaptiveGenerationSizePolicyAtMinorCollection  = true                                {product}
    604      bool UseAdaptiveNUMAChunkSizing                = true                                {product}
    605      bool UseAdaptiveSizeDecayMajorGCCost           = true                                {product}
    606      bool UseAdaptiveSizePolicy                     = true                                {product}
    607      bool UseAdaptiveSizePolicyFootprintGoal        = true                                {product}
    608      bool UseAdaptiveSizePolicyWithSystemGC         = false                               {product}
    609      bool UseAddressNop                             = false                               {ARCH product}
    610      bool UseAltSigs                                = false                               {product}
    611      bool UseAutoGCSelectPolicy                     = false                               {product}
    612      bool UseBMI1Instructions                       = false                               {ARCH product}
    613      bool UseBMI2Instructions                       = false                               {ARCH product}
    614      bool UseBiasedLocking                          = true                                {product}
    615      bool UseBimorphicInlining                      = true                                {C2 product}
    616      bool UseBoundThreads                           = true                                {product}
    617      bool UseCLMUL                                  = false                               {ARCH product}
    618      bool UseCMSBestFit                             = true                                {product}
    619      bool UseCMSCollectionPassing                   = true                                {product}
    620      bool UseCMSCompactAtFullCollection             = true                                {product}
    621      bool UseCMSInitiatingOccupancyOnly             = false                               {product}
    622      bool UseCRC32Intrinsics                        = false                               {product}
    623      bool UseCodeCacheFlushing                      = true                                {product}
    624      bool UseCompiler                               = true                                {product}
    625      bool UseCompilerSafepoints                     = true                                {product}
    626      bool UseCompressedClassPointers                = false                               {lp64_product}
    627      bool UseCompressedOops                         = false                               {lp64_product}
    628      bool UseConcMarkSweepGC                        = false                               {product}
    629      bool UseCondCardMark                           = false                               {C2 product}
    630      bool UseCountLeadingZerosInstruction           = false                               {ARCH product}
    631      bool UseCountTrailingZerosInstruction          = false                               {ARCH product}
    632      bool UseCounterDecay                           = true                                {product}
    633      bool UseDivMod                                 = true                                {C2 product}
    634      bool UseDynamicNumberOfGCThreads               = false                               {product}
    635      bool UseFPUForSpilling                         = false                               {C2 product}
    636      bool UseFastAccessorMethods                    = true                                {product}
    637      bool UseFastEmptyMethods                       = true                                {product}
    638      bool UseFastJNIAccessors                       = true                                {product}
    639      bool UseFastStosb                              = false                               {ARCH product}
    640      bool UseG1GC                                   = false                               {product}
    641      bool UseGCLogFileRotation                      = false                               {product}
    642      bool UseGCOverheadLimit                        = true                                {product}
    643      bool UseGCTaskAffinity                         = false                               {product}
    644      bool UseHeavyMonitors                          = false                               {product}
    645      bool UseInlineCaches                           = true                                {product}
    646      bool UseInterpreter                            = true                                {product}
    647      bool UseJumpTables                             = true                                {C2 product}
    648      bool UseLWPSynchronization                     = true                                {product}
    649      bool UseLargePages                             = false                               {pd product}
    650      bool UseLargePagesInMetaspace                  = false                               {product}
    651      bool UseLargePagesIndividualAllocation        := false                               {pd product}
    652      bool UseLockedTracing                          = false                               {product}
    653      bool UseLoopCounter                            = true                                {product}
    654      bool UseLoopInvariantCodeMotion                = true                                {C1 product}
    655      bool UseLoopPredicate                          = true                                {C2 product}
    656      bool UseMathExactIntrinsics                    = true                                {C2 product}
    657      bool UseMaximumCompactionOnSystemGC            = true                                {product}
    658      bool UseMembar                                 = false                               {pd product}
    659      bool UseMultiplyToLenIntrinsic                 = false                               {C2 product}
    660      bool UseNUMA                                   = false                               {product}
    661      bool UseNUMAInterleaving                       = false                               {product}
    662      bool UseNewLongLShift                          = false                               {ARCH product}
    663      bool UseOSErrorReporting                       = false                               {pd product}
    664      bool UseOldInlining                            = true                                {C2 product}
    665      bool UseOnStackReplacement                     = true                                {pd product}
    666      bool UseOnlyInlinedBimorphic                   = true                                {C2 product}
    667      bool UseOptoBiasInlining                       = true                                {C2 product}
    668      bool UsePSAdaptiveSurvivorSizePolicy           = true                                {product}
    669      bool UseParNewGC                               = false                               {product}
    670      bool UseParallelGC                             = false                               {product}
    671      bool UseParallelOldGC                          = false                               {product}
    672      bool UsePerfData                               = true                                {product}
    673      bool UsePopCountInstruction                    = false                               {product}
    674      bool UseRDPCForConstantTableBase               = false                               {C2 product}
    675      bool UseRTMDeopt                               = false                               {ARCH product}
    676      bool UseRTMLocking                             = false                               {ARCH product}
    677      bool UseSHA                                    = false                               {product}
    678      bool UseSHA1Intrinsics                         = false                               {product}
    679      bool UseSHA256Intrinsics                       = false                               {product}
    680      bool UseSHA512Intrinsics                       = false                               {product}
    681      intx UseSSE                                    = 99                                  {product}
    682      bool UseSSE42Intrinsics                        = false                               {product}
    683      bool UseSerialGC                               = false                               {product}
    684      bool UseSharedSpaces                           = true                                {product}
    685      bool UseSignalChaining                         = true                                {product}
    686      bool UseStoreImmI16                            = true                                {ARCH product}
    687      bool UseStringDeduplication                    = false                               {product}
    688      bool UseSuperWord                              = true                                {C2 product}
    689      bool UseTLAB                                   = true                                {pd product}
    690      bool UseThreadPriorities                       = true                                {pd product}
    691      bool UseTypeProfile                            = true                                {product}
    692      bool UseTypeSpeculation                        = true                                {C2 product}
    693      bool UseUTCFileTimestamp                       = true                                {product}
    694      bool UseUnalignedLoadStores                    = false                               {ARCH product}
    695      bool UseVMInterruptibleIO                      = false                               {product}
    696      bool UseXMMForArrayCopy                        = false                               {product}
    697      bool UseXmmI2D                                 = false                               {ARCH product}
    698      bool UseXmmI2F                                 = false                               {ARCH product}
    699      bool UseXmmLoadAndClearUpper                   = true                                {ARCH product}
    700      bool UseXmmRegToRegMoveAll                     = false                               {ARCH product}
    701      bool VMThreadHintNoPreempt                     = false                               {product}
    702      intx VMThreadPriority                          = -1                                  {product}
    703      intx VMThreadStackSize                         = 0                                   {pd product}
    704      intx ValueMapInitialSize                       = 11                                  {C1 product}
    705      intx ValueMapMaxLoopSize                       = 8                                   {C1 product}
    706      intx ValueSearchLimit                          = 1000                                {C2 product}
    707      bool VerifyMergedCPBytecodes                   = true                                {product}
    708      bool VerifySharedSpaces                        = false                               {product}
    709      intx WorkAroundNPTLTimedWaitHang               = 1                                   {product}
    710     uintx YoungGenerationSizeIncrement              = 20                                  {product}
    711     uintx YoungGenerationSizeSupplement             = 80                                  {product}
    712     uintx YoungGenerationSizeSupplementDecay        = 8                                   {product}
    713     uintx YoungPLABSize                             = 4096                                {product}
    714      bool ZeroTLAB                                  = false                               {product}
    715      intx hashCode                                  = 5                                   {product}

**-XX:+PrintFlagsFinal：**表示打印出XX选项在运行程序时生效的值。示例如下：

![ContractedBlock.gif][] ![ExpandedBlockStart.gif][]

1 C:\Users\zsm>java -XX:+PrintFlagsFinal -version
      2 [Global flags]
      3     uintx AdaptiveSizeDecrementScaleFactor          = 4                                   {product}
      4     uintx AdaptiveSizeMajorGCDecayTimeScale         = 10                                  {product}
      5     uintx AdaptiveSizePausePolicy                   = 0                                   {product}
      6     uintx AdaptiveSizePolicyCollectionCostMargin    = 50                                  {product}
      7     uintx AdaptiveSizePolicyInitializingSteps       = 20                                  {product}
      8     uintx AdaptiveSizePolicyOutputInterval          = 0                                   {product}
      9     uintx AdaptiveSizePolicyWeight                  = 10                                  {product}
     10     uintx AdaptiveSizeThroughPutPolicy              = 0                                   {product}
     11     uintx AdaptiveTimeWeight                        = 25                                  {product}
     12      bool AdjustConcurrency                         = false                               {product}
     13      bool AggressiveOpts                            = false                               {product}
     14      intx AliasLevel                                = 3                                   {C2 product}
     15      bool AlignVector                               = true                                {C2 product}
     16      intx AllocateInstancePrefetchLines             = 1                                   {product}
     17      intx AllocatePrefetchDistance                  = 256                                 {product}
     18      intx AllocatePrefetchInstr                     = 0                                   {product}
     19      intx AllocatePrefetchLines                     = 3                                   {product}
     20      intx AllocatePrefetchStepSize                  = 64                                  {product}
     21      intx AllocatePrefetchStyle                     = 1                                   {product}
     22      bool AllowJNIEnvProxy                          = false                               {product}
     23      bool AllowNonVirtualCalls                      = false                               {product}
     24      bool AllowParallelDefineClass                  = false                               {product}
     25      bool AllowUserSignalHandlers                   = false                               {product}
     26      bool AlwaysActAsServerClassMachine             = false                               {product}
     27      bool AlwaysCompileLoopMethods                  = false                               {product}
     28      bool AlwaysLockClassLoader                     = false                               {product}
     29      bool AlwaysPreTouch                            = false                               {product}
     30      bool AlwaysRestoreFPU                          = false                               {product}
     31      bool AlwaysTenure                              = false                               {product}
     32      bool AssertOnSuspendWaitFailure                = false                               {product}
     33      bool AssumeMP                                  = false                               {product}
     34      intx AutoBoxCacheMax                           = 128                                 {C2 product}
     35     uintx AutoGCSelectPauseMillis                   = 5000                                {product}
     36      intx BCEATraceLevel                            = 0                                   {product}
     37      intx BackEdgeThreshold                         = 100000                              {pd product}
     38      bool BackgroundCompilation                     = true                                {pd product}
     39     uintx BaseFootPrintEstimate                     = 268435456                           {product}
     40      intx BiasedLockingBulkRebiasThreshold          = 20                                  {product}
     41      intx BiasedLockingBulkRevokeThreshold          = 40                                  {product}
     42      intx BiasedLockingDecayTime                    = 25000                               {product}
     43      intx BiasedLockingStartupDelay                 = 4000                                {product}
     44      bool BindGCTaskThreadsToCPUs                   = false                               {product}
     45      bool BlockLayoutByFrequency                    = true                                {C2 product}
     46      intx BlockLayoutMinDiamondPercentage           = 20                                  {C2 product}
     47      bool BlockLayoutRotateLoops                    = true                                {C2 product}
     48      bool BranchOnRegister                          = false                               {C2 product}
     49      bool BytecodeVerificationLocal                 = false                               {product}
     50      bool BytecodeVerificationRemote                = true                                {product}
     51      bool C1OptimizeVirtualCallProfiling            = true                                {C1 product}
     52      bool C1ProfileBranches                         = true                                {C1 product}
     53      bool C1ProfileCalls                            = true                                {C1 product}
     54      bool C1ProfileCheckcasts                       = true                                {C1 product}
     55      bool C1ProfileInlinedCalls                     = true                                {C1 product}
     56      bool C1ProfileVirtualCalls                     = true                                {C1 product}
     57      bool C1UpdateMethodData                        = true                                {C1 product}
     58      intx CICompilerCount                          := 3                                   {product}
     59      bool CICompilerCountPerCPU                     = true                                {product}
     60      bool CITime                                    = false                               {product}
     61      bool CMSAbortSemantics                         = false                               {product}
     62     uintx CMSAbortablePrecleanMinWorkPerIteration   = 100                                 {product}
     63      intx CMSAbortablePrecleanWaitMillis            = 100                                 {manageable}
     64     uintx CMSBitMapYieldQuantum                     = 10485760                            {product}
     65     uintx CMSBootstrapOccupancy                     = 50                                  {product}
     66      bool CMSClassUnloadingEnabled                  = true                                {product}
     67     uintx CMSClassUnloadingMaxInterval              = 0                                   {product}
     68      bool CMSCleanOnEnter                           = true                                {product}
     69      bool CMSCompactWhenClearAllSoftRefs            = true                                {product}
     70     uintx CMSConcMarkMultiple                       = 32                                  {product}
     71      bool CMSConcurrentMTEnabled                    = true                                {product}
     72     uintx CMSCoordinatorYieldSleepCount             = 10                                  {product}
     73      bool CMSDumpAtPromotionFailure                 = false                               {product}
     74      bool CMSEdenChunksRecordAlways                 = true                                {product}
     75     uintx CMSExpAvgFactor                           = 50                                  {product}
     76      bool CMSExtrapolateSweep                       = false                               {product}
     77     uintx CMSFullGCsBeforeCompaction                = 0                                   {product}
     78     uintx CMSIncrementalDutyCycle                   = 10                                  {product}
     79     uintx CMSIncrementalDutyCycleMin                = 0                                   {product}
     80      bool CMSIncrementalMode                        = false                               {product}
     81     uintx CMSIncrementalOffset                      = 0                                   {product}
     82      bool CMSIncrementalPacing                      = true                                {product}
     83     uintx CMSIncrementalSafetyFactor                = 10                                  {product}
     84     uintx CMSIndexedFreeListReplenish               = 4                                   {product}
     85      intx CMSInitiatingOccupancyFraction            = -1                                  {product}
     86     uintx CMSIsTooFullPercentage                    = 98                                  {product}
     87    double CMSLargeCoalSurplusPercent                = 0.950000                            {product}
     88    double CMSLargeSplitSurplusPercent               = 1.000000                            {product}
     89      bool CMSLoopWarn                               = false                               {product}
     90     uintx CMSMaxAbortablePrecleanLoops              = 0                                   {product}
     91      intx CMSMaxAbortablePrecleanTime               = 5000                                {product}
     92     uintx CMSOldPLABMax                             = 1024                                {product}
     93     uintx CMSOldPLABMin                             = 16                                  {product}
     94     uintx CMSOldPLABNumRefills                      = 4                                   {product}
     95     uintx CMSOldPLABReactivityFactor                = 2                                   {product}
     96      bool CMSOldPLABResizeQuicker                   = false                               {product}
     97     uintx CMSOldPLABToleranceFactor                 = 4                                   {product}
     98      bool CMSPLABRecordAlways                       = true                                {product}
     99     uintx CMSParPromoteBlocksToClaim                = 16                                  {product}
    100      bool CMSParallelInitialMarkEnabled             = true                                {product}
    101      bool CMSParallelRemarkEnabled                  = true                                {product}
    102      bool CMSParallelSurvivorRemarkEnabled          = true                                {product}
    103     uintx CMSPrecleanDenominator                    = 3                                   {product}
    104     uintx CMSPrecleanIter                           = 3                                   {product}
    105     uintx CMSPrecleanNumerator                      = 2                                   {product}
    106      bool CMSPrecleanRefLists1                      = true                                {product}
    107      bool CMSPrecleanRefLists2                      = false                               {product}
    108      bool CMSPrecleanSurvivors1                     = false                               {product}
    109      bool CMSPrecleanSurvivors2                     = true                                {product}
    110     uintx CMSPrecleanThreshold                      = 1000                                {product}
    111      bool CMSPrecleaningEnabled                     = true                                {product}
    112      bool CMSPrintChunksInDump                      = false                               {product}
    113      bool CMSPrintEdenSurvivorChunks                = false                               {product}
    114      bool CMSPrintObjectsInDump                     = false                               {product}
    115     uintx CMSRemarkVerifyVariant                    = 1                                   {product}
    116      bool CMSReplenishIntermediate                  = true                                {product}
    117     uintx CMSRescanMultiple                         = 32                                  {product}
    118     uintx CMSSamplingGrain                          = 16384                               {product}
    119      bool CMSScavengeBeforeRemark                   = false                               {product}
    120     uintx CMSScheduleRemarkEdenPenetration          = 50                                  {product}
    121     uintx CMSScheduleRemarkEdenSizeThreshold        = 2097152                             {product}
    122     uintx CMSScheduleRemarkSamplingRatio            = 5                                   {product}
    123    double CMSSmallCoalSurplusPercent                = 1.050000                            {product}
    124    double CMSSmallSplitSurplusPercent               = 1.100000                            {product}
    125      bool CMSSplitIndexedFreeListBlocks             = true                                {product}
    126      intx CMSTriggerInterval                        = -1                                  {manageable}
    127     uintx CMSTriggerRatio                           = 80                                  {product}
    128      intx CMSWaitDuration                           = 2000                                {manageable}
    129     uintx CMSWorkQueueDrainThreshold                = 10                                  {product}
    130      bool CMSYield                                  = true                                {product}
    131     uintx CMSYieldSleepCount                        = 0                                   {product}
    132     uintx CMSYoungGenPerWorker                      = 67108864                            {pd product}
    133     uintx CMS_FLSPadding                            = 1                                   {product}
    134     uintx CMS_FLSWeight                             = 75                                  {product}
    135     uintx CMS_SweepPadding                          = 1                                   {product}
    136     uintx CMS_SweepTimerThresholdMillis             = 10                                  {product}
    137     uintx CMS_SweepWeight                           = 75                                  {product}
    138      bool CheckEndorsedAndExtDirs                   = false                               {product}
    139      bool CheckJNICalls                             = false                               {product}
    140      bool ClassUnloading                            = true                                {product}
    141      bool ClassUnloadingWithConcurrentMark          = true                                {product}
    142      intx ClearFPUAtPark                            = 0                                   {product}
    143      bool ClipInlining                              = true                                {product}
    144     uintx CodeCacheExpansionSize                    = 65536                               {pd product}
    145     uintx CodeCacheMinimumFreeSpace                 = 512000                              {product}
    146      bool CollectGen0First                          = false                               {product}
    147      bool CompactFields                             = true                                {product}
    148      intx CompilationPolicyChoice                   = 3                                   {product}
    149 ccstrlist CompileCommand                            =                                     {product}
    150     ccstr CompileCommandFile                        =                                     {product}
    151 ccstrlist CompileOnly                               =                                     {product}
    152      intx CompileThreshold                          = 10000                               {pd product}
    153      bool CompilerThreadHintNoPreempt               = true                                {product}
    154      intx CompilerThreadPriority                    = -1                                  {product}
    155      intx CompilerThreadStackSize                   = 0                                   {pd product}
    156     uintx CompressedClassSpaceSize                  = 1073741824                          {product}
    157     uintx ConcGCThreads                             = 0                                   {product}
    158      intx ConditionalMoveLimit                      = 3                                   {C2 pd product}
    159      intx ContendedPaddingWidth                     = 128                                 {product}
    160      bool ConvertSleepToYield                       = true                                {pd product}
    161      bool ConvertYieldToSleep                       = false                               {product}
    162      bool CreateMinidumpOnCrash                     = false                               {product}
    163      bool CriticalJNINatives                        = true                                {product}
    164      bool DTraceAllocProbes                         = false                               {product}
    165      bool DTraceMethodProbes                        = false                               {product}
    166      bool DTraceMonitorProbes                       = false                               {product}
    167      bool Debugging                                 = false                               {product}
    168     uintx DefaultMaxRAMFraction                     = 4                                   {product}
    169      intx DefaultThreadPriority                     = -1                                  {product}
    170      intx DeferPollingPageLoopCount                 = -1                                  {product}
    171      intx DeferThrSuspendLoopCount                  = 4000                                {product}
    172      bool DeoptimizeRandom                          = false                               {product}
    173      bool DisableAttachMechanism                    = false                               {product}
    174      bool DisableExplicitGC                         = false                               {product}
    175      bool DisplayVMOutputToStderr                   = false                               {product}
    176      bool DisplayVMOutputToStdout                   = false                               {product}
    177      bool DoEscapeAnalysis                          = true                                {C2 product}
    178      bool DontCompileHugeMethods                    = true                                {product}
    179      bool DontYieldALot                             = false                               {pd product}
    180     ccstr DumpLoadedClassList                       =                                     {product}
    181      bool DumpReplayDataOnError                     = true                                {product}
    182      bool DumpSharedSpaces                          = false                               {product}
    183      bool EagerXrunInit                             = false                               {product}
    184      intx EliminateAllocationArraySizeLimit         = 64                                  {C2 product}
    185      bool EliminateAllocations                      = true                                {C2 product}
    186      bool EliminateAutoBox                          = true                                {C2 product}
    187      bool EliminateLocks                            = true                                {C2 product}
    188      bool EliminateNestedLocks                      = true                                {C2 product}
    189      intx EmitSync                                  = 0                                   {product}
    190      bool EnableContended                           = true                                {product}
    191      bool EnableSharedLookupCache                   = true                                {product}
    192      bool EnableTracing                             = false                               {product}
    193     uintx ErgoHeapSizeLimit                         = 0                                   {product}
    194     ccstr ErrorFile                                 =                                     {product}
    195     ccstr ErrorReportServer                         =                                     {product}
    196    double EscapeAnalysisTimeout                     = 20.000000                           {C2 product}
    197      bool EstimateArgEscape                         = true                                {product}
    198      bool ExplicitGCInvokesConcurrent               = false                               {product}
    199      bool ExplicitGCInvokesConcurrentAndUnloadsClasses  = false                               {product}
    200      bool ExtendedDTraceProbes                      = false                               {product}
    201     ccstr ExtraSharedClassListFile                  =                                     {product}
    202      bool FLSAlwaysCoalesceLarge                    = false                               {product}
    203     uintx FLSCoalescePolicy                         = 2                                   {product}
    204    double FLSLargestBlockCoalesceProximity          = 0.990000                            {product}
    205      bool FailOverToOldVerifier                     = true                                {product}
    206      bool FastTLABRefill                            = true                                {product}
    207      intx FenceInstruction                          = 0                                   {ARCH product}
    208      intx FieldsAllocationStyle                     = 1                                   {product}
    209      bool FilterSpuriousWakeups                     = true                                {product}
    210     ccstr FlightRecorderOptions                     =                                     {product}
    211      bool ForceNUMA                                 = false                               {product}
    212      bool ForceTimeHighResolution                   = false                               {product}
    213      intx FreqInlineSize                            = 325                                 {pd product}
    214    double G1ConcMarkStepDurationMillis              = 10.000000                           {product}
    215     uintx G1ConcRSHotCardLimit                      = 4                                   {product}
    216     uintx G1ConcRSLogCacheSize                      = 10                                  {product}
    217      intx G1ConcRefinementGreenZone                 = 0                                   {product}
    218      intx G1ConcRefinementRedZone                   = 0                                   {product}
    219      intx G1ConcRefinementServiceIntervalMillis     = 300                                 {product}
    220     uintx G1ConcRefinementThreads                   = 0                                   {product}
    221      intx G1ConcRefinementThresholdStep             = 0                                   {product}
    222      intx G1ConcRefinementYellowZone                = 0                                   {product}
    223     uintx G1ConfidencePercent                       = 50                                  {product}
    224     uintx G1HeapRegionSize                          = 0                                   {product}
    225     uintx G1HeapWastePercent                        = 5                                   {product}
    226     uintx G1MixedGCCountTarget                      = 8                                   {product}
    227      intx G1RSetRegionEntries                       = 0                                   {product}
    228     uintx G1RSetScanBlockSize                       = 64                                  {product}
    229      intx G1RSetSparseRegionEntries                 = 0                                   {product}
    230      intx G1RSetUpdatingPauseTimePercent            = 10                                  {product}
    231      intx G1RefProcDrainInterval                    = 10                                  {product}
    232     uintx G1ReservePercent                          = 10                                  {product}
    233     uintx G1SATBBufferEnqueueingThresholdPercent    = 60                                  {product}
    234      intx G1SATBBufferSize                          = 1024                                {product}
    235      intx G1UpdateBufferSize                        = 256                                 {product}
    236      bool G1UseAdaptiveConcRefinement               = true                                {product}
    237     uintx GCDrainStackTargetSize                    = 64                                  {product}
    238     uintx GCHeapFreeLimit                           = 2                                   {product}
    239     uintx GCLockerEdenExpansionPercent              = 5                                   {product}
    240      bool GCLockerInvokesConcurrent                 = false                               {product}
    241     uintx GCLogFileSize                             = 8192                                {product}
    242     uintx GCPauseIntervalMillis                     = 0                                   {product}
    243     uintx GCTaskTimeStampEntries                    = 200                                 {product}
    244     uintx GCTimeLimit                               = 98                                  {product}
    245     uintx GCTimeRatio                               = 99                                  {product}
    246     uintx HeapBaseMinAddress                        = 2147483648                          {pd product}
    247      bool HeapDumpAfterFullGC                       = false                               {manageable}
    248      bool HeapDumpBeforeFullGC                      = false                               {manageable}
    249      bool HeapDumpOnOutOfMemoryError                = false                               {manageable}
    250     ccstr HeapDumpPath                              =                                     {manageable}
    251     uintx HeapFirstMaximumCompactionCount           = 3                                   {product}
    252     uintx HeapMaximumCompactionInterval             = 20                                  {product}
    253     uintx HeapSizePerGCThread                       = 87241520                            {product}
    254      bool IgnoreEmptyClassPaths                     = false                               {product}
    255      bool IgnoreUnrecognizedVMOptions               = false                               {product}
    256     uintx IncreaseFirstTierCompileThresholdAt       = 50                                  {product}
    257      bool IncrementalInline                         = true                                {C2 product}
    258     uintx InitialBootClassLoaderMetaspaceSize       = 4194304                             {product}
    259     uintx InitialCodeCacheSize                      = 2555904                             {pd product}
    260     uintx InitialHeapSize                          := 134217728                           {product}
    261     uintx InitialRAMFraction                        = 64                                  {product}
    262     uintx InitialSurvivorRatio                      = 8                                   {product}
    263     uintx InitialTenuringThreshold                  = 7                                   {product}
    264     uintx InitiatingHeapOccupancyPercent            = 45                                  {product}
    265      bool Inline                                    = true                                {product}
    266     ccstr InlineDataFile                            =                                     {product}
    267      intx InlineSmallCode                           = 2000                                {pd product}
    268      bool InlineSynchronizedMethods                 = true                                {C1 product}
    269      bool InsertMemBarAfterArraycopy                = true                                {C2 product}
    270      intx InteriorEntryAlignment                    = 16                                  {C2 pd product}
    271      intx InterpreterProfilePercentage              = 33                                  {product}
    272      bool JNIDetachReleasesMonitors                 = true                                {product}
    273      bool JavaMonitorsInStackTrace                  = true                                {product}
    274      intx JavaPriority10_To_OSPriority              = -1                                  {product}
    275      intx JavaPriority1_To_OSPriority               = -1                                  {product}
    276      intx JavaPriority2_To_OSPriority               = -1                                  {product}
    277      intx JavaPriority3_To_OSPriority               = -1                                  {product}
    278      intx JavaPriority4_To_OSPriority               = -1                                  {product}
    279      intx JavaPriority5_To_OSPriority               = -1                                  {product}
    280      intx JavaPriority6_To_OSPriority               = -1                                  {product}
    281      intx JavaPriority7_To_OSPriority               = -1                                  {product}
    282      intx JavaPriority8_To_OSPriority               = -1                                  {product}
    283      intx JavaPriority9_To_OSPriority               = -1                                  {product}
    284      bool LIRFillDelaySlots                         = false                               {C1 pd product}
    285     uintx LargePageHeapSizeThreshold                = 134217728                           {product}
    286     uintx LargePageSizeInBytes                      = 0                                   {product}
    287      bool LazyBootClassLoader                       = true                                {product}
    288      intx LiveNodeCountInliningCutoff               = 40000                               {C2 product}
    289      bool LogCommercialFeatures                     = false                               {product}
    290      intx LoopMaxUnroll                             = 16                                  {C2 product}
    291      intx LoopOptsCount                             = 43                                  {C2 product}
    292      intx LoopUnrollLimit                           = 60                                  {C2 pd product}
    293      intx LoopUnrollMin                             = 4                                   {C2 product}
    294      bool LoopUnswitching                           = true                                {C2 product}
    295      bool ManagementServer                          = false                               {product}
    296     uintx MarkStackSize                             = 4194304                             {product}
    297     uintx MarkStackSizeMax                          = 536870912                           {product}
    298     uintx MarkSweepAlwaysCompactCount               = 4                                   {product}
    299     uintx MarkSweepDeadRatio                        = 1                                   {product}
    300      intx MaxBCEAEstimateLevel                      = 5                                   {product}
    301      intx MaxBCEAEstimateSize                       = 150                                 {product}
    302     uintx MaxDirectMemorySize                       = 0                                   {product}
    303      bool MaxFDLimit                                = true                                {product}
    304     uintx MaxGCMinorPauseMillis                     = 4294967295                          {product}
    305     uintx MaxGCPauseMillis                          = 4294967295                          {product}
    306     uintx MaxHeapFreeRatio                          = 100                                 {manageable}
    307     uintx MaxHeapSize                              := 2124414976                          {product}
    308      intx MaxInlineLevel                            = 9                                   {product}
    309      intx MaxInlineSize                             = 35                                  {product}
    310      intx MaxJNILocalCapacity                       = 65536                               {product}
    311      intx MaxJavaStackTraceDepth                    = 1024                                {product}
    312      intx MaxJumpTableSize                          = 65000                               {C2 product}
    313      intx MaxJumpTableSparseness                    = 5                                   {C2 product}
    314      intx MaxLabelRootDepth                         = 1100                                {C2 product}
    315      intx MaxLoopPad                                = 11                                  {C2 product}
    316     uintx MaxMetaspaceExpansion                     = 5451776                             {product}
    317     uintx MaxMetaspaceFreeRatio                     = 70                                  {product}
    318     uintx MaxMetaspaceSize                          = 4294901760                          {product}
    319     uintx MaxNewSize                               := 707788800                           {product}
    320      intx MaxNodeLimit                              = 75000                               {C2 product}
    321  uint64_t MaxRAM                                    = 0                                   {pd product}
    322     uintx MaxRAMFraction                            = 4                                   {product}
    323      intx MaxRecursiveInlineLevel                   = 1                                   {product}
    324     uintx MaxTenuringThreshold                      = 15                                  {product}
    325      intx MaxTrivialSize                            = 6                                   {product}
    326      intx MaxVectorSize                             = 32                                  {C2 product}
    327     uintx MetaspaceSize                             = 21807104                            {pd product}
    328      bool MethodFlushing                            = true                                {product}
    329     uintx MinHeapDeltaBytes                        := 524288                              {product}
    330     uintx MinHeapFreeRatio                          = 0                                   {manageable}
    331      intx MinInliningThreshold                      = 250                                 {product}
    332      intx MinJumpTableSize                          = 10                                  {C2 pd product}
    333     uintx MinMetaspaceExpansion                     = 339968                              {product}
    334     uintx MinMetaspaceFreeRatio                     = 40                                  {product}
    335     uintx MinRAMFraction                            = 2                                   {product}
    336     uintx MinSurvivorRatio                          = 3                                   {product}
    337     uintx MinTLABSize                               = 2048                                {product}
    338      intx MonitorBound                              = 0                                   {product}
    339      bool MonitorInUseLists                         = false                               {product}
    340      intx MultiArrayExpandLimit                     = 6                                   {C2 product}
    341      bool MustCallLoadClassInternal                 = false                               {product}
    342     uintx NUMAChunkResizeWeight                     = 20                                  {product}
    343     uintx NUMAInterleaveGranularity                 = 2097152                             {product}
    344     uintx NUMAPageScanRate                          = 256                                 {product}
    345     uintx NUMASpaceResizeRate                       = 1073741824                          {product}
    346      bool NUMAStats                                 = false                               {product}
    347     ccstr NativeMemoryTracking                      = off                                 {product}
    348      bool NeedsDeoptSuspend                         = false                               {pd product}
    349      bool NeverActAsServerClassMachine              = false                               {pd product}
    350      bool NeverTenure                               = false                               {product}
    351     uintx NewRatio                                  = 2                                   {product}
    352     uintx NewSize                                  := 44564480                            {product}
    353     uintx NewSizeThreadIncrease                     = 5320                                {pd product}
    354      intx NmethodSweepActivity                      = 10                                  {product}
    355      intx NmethodSweepCheckInterval                 = 5                                   {product}
    356      intx NmethodSweepFraction                      = 16                                  {product}
    357      intx NodeLimitFudgeFactor                      = 2000                                {C2 product}
    358     uintx NumberOfGCLogFiles                        = 0                                   {product}
    359      intx NumberOfLoopInstrToAlign                  = 4                                   {C2 product}
    360      intx ObjectAlignmentInBytes                    = 8                                   {lp64_product}
    361     uintx OldPLABSize                               = 1024                                {product}
    362     uintx OldPLABWeight                             = 50                                  {product}
    363     uintx OldSize                                  := 89653248                            {product}
    364      bool OmitStackTraceInFastThrow                 = true                                {product}
    365 ccstrlist OnError                                   =                                     {product}
    366 ccstrlist OnOutOfMemoryError                        =                                     {product}
    367      intx OnStackReplacePercentage                  = 140                                 {pd product}
    368      bool OptimizeFill                              = true                                {C2 product}
    369      bool OptimizePtrCompare                        = true                                {C2 product}
    370      bool OptimizeStringConcat                      = true                                {C2 product}
    371      bool OptoBundling                              = false                               {C2 pd product}
    372      intx OptoLoopAlignment                         = 16                                  {pd product}
    373      bool OptoScheduling                            = false                               {C2 pd product}
    374     uintx PLABWeight                                = 75                                  {product}
    375      bool PSChunkLargeArrays                        = true                                {product}
    376      intx ParGCArrayScanChunk                       = 50                                  {product}
    377     uintx ParGCDesiredObjsFromOverflowList          = 20                                  {product}
    378      bool ParGCTrimOverflow                         = true                                {product}
    379      bool ParGCUseLocalOverflow                     = false                               {product}
    380     uintx ParallelGCBufferWastePct                  = 10                                  {product}
    381     uintx ParallelGCThreads                         = 4                                   {product}
    382      bool ParallelGCVerbose                         = false                               {product}
    383     uintx ParallelOldDeadWoodLimiterMean            = 50                                  {product}
    384     uintx ParallelOldDeadWoodLimiterStdDev          = 80                                  {product}
    385      bool ParallelRefProcBalancingEnabled           = true                                {product}
    386      bool ParallelRefProcEnabled                    = false                               {product}
    387      bool PartialPeelAtUnsignedTests                = true                                {C2 product}
    388      bool PartialPeelLoop                           = true                                {C2 product}
    389      intx PartialPeelNewPhiDelta                    = 0                                   {C2 product}
    390     uintx PausePadding                              = 1                                   {product}
    391      intx PerBytecodeRecompilationCutoff            = 200                                 {product}
    392      intx PerBytecodeTrapLimit                      = 4                                   {product}
    393      intx PerMethodRecompilationCutoff              = 400                                 {product}
    394      intx PerMethodTrapLimit                        = 100                                 {product}
    395      bool PerfAllowAtExitRegistration               = false                               {product}
    396      bool PerfBypassFileSystemCheck                 = false                               {product}
    397      intx PerfDataMemorySize                        = 32768                               {product}
    398      intx PerfDataSamplingInterval                  = 50                                  {product}
    399     ccstr PerfDataSaveFile                          =                                     {product}
    400      bool PerfDataSaveToFile                        = false                               {product}
    401      bool PerfDisableSharedMem                      = false                               {product}
    402      intx PerfMaxStringConstLength                  = 1024                                {product}
    403      intx PreInflateSpin                            = 10                                  {pd product}
    404      bool PreferInterpreterNativeStubs              = false                               {pd product}
    405      intx PrefetchCopyIntervalInBytes               = 576                                 {product}
    406      intx PrefetchFieldsAhead                       = 1                                   {product}
    407      intx PrefetchScanIntervalInBytes               = 576                                 {product}
    408      bool PreserveAllAnnotations                    = false                               {product}
    409     uintx PretenureSizeThreshold                    = 0                                   {product}
    410      bool PrintAdaptiveSizePolicy                   = false                               {product}
    411      bool PrintCMSInitiationStatistics              = false                               {product}
    412      intx PrintCMSStatistics                        = 0                                   {product}
    413      bool PrintClassHistogram                       = false                               {manageable}
    414      bool PrintClassHistogramAfterFullGC            = false                               {manageable}
    415      bool PrintClassHistogramBeforeFullGC           = false                               {manageable}
    416      bool PrintCodeCache                            = false                               {product}
    417      bool PrintCodeCacheOnCompilation               = false                               {product}
    418      bool PrintCommandLineFlags                     = false                               {product}
    419      bool PrintCompilation                          = false                               {product}
    420      bool PrintConcurrentLocks                      = false                               {manageable}
    421      intx PrintFLSCensus                            = 0                                   {product}
    422      intx PrintFLSStatistics                        = 0                                   {product}
    423      bool PrintFlagsFinal                          := true                                {product}
    424      bool PrintFlagsInitial                         = false                               {product}
    425      bool PrintGC                                   = false                               {manageable}
    426      bool PrintGCApplicationConcurrentTime          = false                               {product}
    427      bool PrintGCApplicationStoppedTime             = false                               {product}
    428      bool PrintGCCause                              = true                                {product}
    429      bool PrintGCDateStamps                         = false                               {manageable}
    430      bool PrintGCDetails                            = false                               {manageable}
    431      bool PrintGCID                                 = false                               {manageable}
    432      bool PrintGCTaskTimeStamps                     = false                               {product}
    433      bool PrintGCTimeStamps                         = false                               {manageable}
    434      bool PrintHeapAtGC                             = false                               {product rw}
    435      bool PrintHeapAtGCExtended                     = false                               {product rw}
    436      bool PrintHeapAtSIGBREAK                       = true                                {product}
    437      bool PrintJNIGCStalls                          = false                               {product}
    438      bool PrintJNIResolving                         = false                               {product}
    439      bool PrintOldPLAB                              = false                               {product}
    440      bool PrintOopAddress                           = false                               {product}
    441      bool PrintPLAB                                 = false                               {product}
    442      bool PrintParallelOldGCPhaseTimes              = false                               {product}
    443      bool PrintPromotionFailure                     = false                               {product}
    444      bool PrintReferenceGC                          = false                               {product}
    445      bool PrintSafepointStatistics                  = false                               {product}
    446      intx PrintSafepointStatisticsCount             = 300                                 {product}
    447      intx PrintSafepointStatisticsTimeout           = -1                                  {product}
    448      bool PrintSharedArchiveAndExit                 = false                               {product}
    449      bool PrintSharedDictionary                     = false                               {product}
    450      bool PrintSharedSpaces                         = false                               {product}
    451      bool PrintStringDeduplicationStatistics        = false                               {product}
    452      bool PrintStringTableStatistics                = false                               {product}
    453      bool PrintTLAB                                 = false                               {product}
    454      bool PrintTenuringDistribution                 = false                               {product}
    455      bool PrintTieredEvents                         = false                               {product}
    456      bool PrintVMOptions                            = false                               {product}
    457      bool PrintVMQWaitTime                          = false                               {product}
    458      bool PrintWarnings                             = true                                {product}
    459     uintx ProcessDistributionStride                 = 4                                   {product}
    460      bool ProfileInterpreter                        = true                                {pd product}
    461      bool ProfileIntervals                          = false                               {product}
    462      intx ProfileIntervalsTicks                     = 100                                 {product}
    463      intx ProfileMaturityPercentage                 = 20                                  {product}
    464      bool ProfileVM                                 = false                               {product}
    465      bool ProfilerPrintByteCodeStatistics           = false                               {product}
    466      bool ProfilerRecordPC                          = false                               {product}
    467     uintx PromotedPadding                           = 3                                   {product}
    468     uintx QueuedAllocationWarningCount              = 0                                   {product}
    469     uintx RTMRetryCount                             = 5                                   {ARCH product}
    470      bool RangeCheckElimination                     = true                                {product}
    471      intx ReadPrefetchInstr                         = 0                                   {ARCH product}
    472      bool ReassociateInvariants                     = true                                {C2 product}
    473      bool ReduceBulkZeroing                         = true                                {C2 product}
    474      bool ReduceFieldZeroing                        = true                                {C2 product}
    475      bool ReduceInitialCardMarks                    = true                                {C2 product}
    476      bool ReduceSignalUsage                         = false                               {product}
    477      intx RefDiscoveryPolicy                        = 0                                   {product}
    478      bool ReflectionWrapResolutionErrors            = true                                {product}
    479      bool RegisterFinalizersAtInit                  = true                                {product}
    480      bool RelaxAccessControlCheck                   = false                               {product}
    481     ccstr ReplayDataFile                            =                                     {product}
    482      bool RequireSharedSpaces                       = false                               {product}
    483     uintx ReservedCodeCacheSize                     = 251658240                           {pd product}
    484      bool ResizeOldPLAB                             = true                                {product}
    485      bool ResizePLAB                                = true                                {product}
    486      bool ResizeTLAB                                = true                                {pd product}
    487      bool RestoreMXCSROnJNICalls                    = false                               {product}
    488      bool RestrictContended                         = true                                {product}
    489      bool RewriteBytecodes                          = true                                {pd product}
    490      bool RewriteFrequentPairs                      = true                                {pd product}
    491      intx SafepointPollOffset                       = 256                                 {C1 pd product}
    492      intx SafepointSpinBeforeYield                  = 2000                                {product}
    493      bool SafepointTimeout                          = false                               {product}
    494      intx SafepointTimeoutDelay                     = 10000                               {product}
    495      bool ScavengeBeforeFullGC                      = true                                {product}
    496      intx SelfDestructTimer                         = 0                                   {product}
    497     uintx SharedBaseAddress                         = 0                                   {product}
    498     ccstr SharedClassListFile                       =                                     {product}
    499     uintx SharedMiscCodeSize                        = 122880                              {product}
    500     uintx SharedMiscDataSize                        = 4194304                             {product}
    501     uintx SharedReadOnlySize                        = 16777216                            {product}
    502     uintx SharedReadWriteSize                       = 16777216                            {product}
    503      bool ShowMessageBoxOnError                     = false                               {product}
    504      intx SoftRefLRUPolicyMSPerMB                   = 1000                                {product}
    505      bool SpecialEncodeISOArray                     = true                                {C2 product}
    506      bool SplitIfBlocks                             = true                                {C2 product}
    507      intx StackRedPages                             = 1                                   {pd product}
    508      intx StackShadowPages                          = 6                                   {pd product}
    509      bool StackTraceInThrowable                     = true                                {product}
    510      intx StackYellowPages                          = 3                                   {pd product}
    511      bool StartAttachListener                       = false                               {product}
    512      intx StarvationMonitorInterval                 = 200                                 {product}
    513      bool StressLdcRewrite                          = false                               {product}
    514     uintx StringDeduplicationAgeThreshold           = 3                                   {product}
    515     uintx StringTableSize                           = 60013                               {product}
    516      bool SuppressFatalErrorMessage                 = false                               {product}
    517     uintx SurvivorPadding                           = 3                                   {product}
    518     uintx SurvivorRatio                             = 8                                   {product}
    519      intx SuspendRetryCount                         = 50                                  {product}
    520      intx SuspendRetryDelay                         = 5                                   {product}
    521      intx SyncFlags                                 = 0                                   {product}
    522     ccstr SyncKnobs                                 =                                     {product}
    523      intx SyncVerbose                               = 0                                   {product}
    524     uintx TLABAllocationWeight                      = 35                                  {product}
    525     uintx TLABRefillWasteFraction                   = 64                                  {product}
    526     uintx TLABSize                                  = 0                                   {product}
    527      bool TLABStats                                 = true                                {product}
    528     uintx TLABWasteIncrement                        = 4                                   {product}
    529     uintx TLABWasteTargetPercent                    = 1                                   {product}
    530     uintx TargetPLABWastePct                        = 10                                  {product}
    531     uintx TargetSurvivorRatio                       = 50                                  {product}
    532     uintx TenuredGenerationSizeIncrement            = 20                                  {product}
    533     uintx TenuredGenerationSizeSupplement           = 80                                  {product}
    534     uintx TenuredGenerationSizeSupplementDecay      = 2                                   {product}
    535      intx ThreadPriorityPolicy                      = 0                                   {product}
    536      bool ThreadPriorityVerbose                     = false                               {product}
    537     uintx ThreadSafetyMargin                        = 52428800                            {product}
    538      intx ThreadStackSize                           = 0                                   {pd product}
    539     uintx ThresholdTolerance                        = 10                                  {product}
    540      intx Tier0BackedgeNotifyFreqLog                = 10                                  {product}
    541      intx Tier0InvokeNotifyFreqLog                  = 7                                   {product}
    542      intx Tier0ProfilingStartPercentage             = 200                                 {product}
    543      intx Tier23InlineeNotifyFreqLog                = 20                                  {product}
    544      intx Tier2BackEdgeThreshold                    = 0                                   {product}
    545      intx Tier2BackedgeNotifyFreqLog                = 14                                  {product}
    546      intx Tier2CompileThreshold                     = 0                                   {product}
    547      intx Tier2InvokeNotifyFreqLog                  = 11                                  {product}
    548      intx Tier3BackEdgeThreshold                    = 60000                               {product}
    549      intx Tier3BackedgeNotifyFreqLog                = 13                                  {product}
    550      intx Tier3CompileThreshold                     = 2000                                {product}
    551      intx Tier3DelayOff                             = 2                                   {product}
    552      intx Tier3DelayOn                              = 5                                   {product}
    553      intx Tier3InvocationThreshold                  = 200                                 {product}
    554      intx Tier3InvokeNotifyFreqLog                  = 10                                  {product}
    555      intx Tier3LoadFeedback                         = 5                                   {product}
    556      intx Tier3MinInvocationThreshold               = 100                                 {product}
    557      intx Tier4BackEdgeThreshold                    = 40000                               {product}
    558      intx Tier4CompileThreshold                     = 15000                               {product}
    559      intx Tier4InvocationThreshold                  = 5000                                {product}
    560      intx Tier4LoadFeedback                         = 3                                   {product}
    561      intx Tier4MinInvocationThreshold               = 600                                 {product}
    562      bool TieredCompilation                         = true                                {pd product}
    563      intx TieredCompileTaskTimeout                  = 50                                  {product}
    564      intx TieredRateUpdateMaxTime                   = 25                                  {product}
    565      intx TieredRateUpdateMinTime                   = 1                                   {product}
    566      intx TieredStopAtLevel                         = 4                                   {product}
    567      bool TimeLinearScan                            = false                               {C1 product}
    568      bool TraceBiasedLocking                        = false                               {product}
    569      bool TraceClassLoading                         = false                               {product rw}
    570      bool TraceClassLoadingPreorder                 = false                               {product}
    571      bool TraceClassPaths                           = false                               {product}
    572      bool TraceClassResolution                      = false                               {product}
    573      bool TraceClassUnloading                       = false                               {product rw}
    574      bool TraceDynamicGCThreads                     = false                               {product}
    575      bool TraceGen0Time                             = false                               {product}
    576      bool TraceGen1Time                             = false                               {product}
    577     ccstr TraceJVMTI                                =                                     {product}
    578      bool TraceLoaderConstraints                    = false                               {product rw}
    579      bool TraceMetadataHumongousAllocation          = false                               {product}
    580      bool TraceMonitorInflation                     = false                               {product}
    581      bool TraceParallelOldGCTasks                   = false                               {product}
    582      intx TraceRedefineClasses                      = 0                                   {product}
    583      bool TraceSafepointCleanupTime                 = false                               {product}
    584      bool TraceSharedLookupCache                    = false                               {product}
    585      bool TraceSuspendWaitFailures                  = false                               {product}
    586      intx TrackedInitializationLimit                = 50                                  {C2 product}
    587      bool TransmitErrorReport                       = false                               {product}
    588      bool TrapBasedNullChecks                       = false                               {pd product}
    589      bool TrapBasedRangeChecks                      = false                               {C2 pd product}
    590      intx TypeProfileArgsLimit                      = 2                                   {product}
    591     uintx TypeProfileLevel                          = 111                                 {pd product}
    592      intx TypeProfileMajorReceiverPercent           = 90                                  {C2 product}
    593      intx TypeProfileParmsLimit                     = 2                                   {product}
    594      intx TypeProfileWidth                          = 2                                   {product}
    595      intx UnguardOnExecutionViolation               = 0                                   {product}
    596      bool UnlinkSymbolsALot                         = false                               {product}
    597      bool Use486InstrsOnly                          = false                               {ARCH product}
    598      bool UseAES                                    = true                                {product}
    599      bool UseAESIntrinsics                          = true                                {product}
    600      intx UseAVX                                    = 2                                   {ARCH product}
    601      bool UseAdaptiveGCBoundary                     = false                               {product}
    602      bool UseAdaptiveGenerationSizePolicyAtMajorCollection  = true                                {product}
    603      bool UseAdaptiveGenerationSizePolicyAtMinorCollection  = true                                {product}
    604      bool UseAdaptiveNUMAChunkSizing                = true                                {product}
    605      bool UseAdaptiveSizeDecayMajorGCCost           = true                                {product}
    606      bool UseAdaptiveSizePolicy                     = true                                {product}
    607      bool UseAdaptiveSizePolicyFootprintGoal        = true                                {product}
    608      bool UseAdaptiveSizePolicyWithSystemGC         = false                               {product}
    609      bool UseAddressNop                             = true                                {ARCH product}
    610      bool UseAltSigs                                = false                               {product}
    611      bool UseAutoGCSelectPolicy                     = false                               {product}
    612      bool UseBMI1Instructions                       = true                                {ARCH product}
    613      bool UseBMI2Instructions                       = true                                {ARCH product}
    614      bool UseBiasedLocking                          = true                                {product}
    615      bool UseBimorphicInlining                      = true                                {C2 product}
    616      bool UseBoundThreads                           = true                                {product}
    617      bool UseCLMUL                                  = true                                {ARCH product}
    618      bool UseCMSBestFit                             = true                                {product}
    619      bool UseCMSCollectionPassing                   = true                                {product}
    620      bool UseCMSCompactAtFullCollection             = true                                {product}
    621      bool UseCMSInitiatingOccupancyOnly             = false                               {product}
    622      bool UseCRC32Intrinsics                        = true                                {product}
    623      bool UseCodeCacheFlushing                      = true                                {product}
    624      bool UseCompiler                               = true                                {product}
    625      bool UseCompilerSafepoints                     = true                                {product}
    626      bool UseCompressedClassPointers               := true                                {lp64_product}
    627      bool UseCompressedOops                        := true                                {lp64_product}
    628      bool UseConcMarkSweepGC                        = false                               {product}
    629      bool UseCondCardMark                           = false                               {C2 product}
    630      bool UseCountLeadingZerosInstruction           = true                                {ARCH product}
    631      bool UseCountTrailingZerosInstruction          = true                                {ARCH product}
    632      bool UseCounterDecay                           = true                                {product}
    633      bool UseDivMod                                 = true                                {C2 product}
    634      bool UseDynamicNumberOfGCThreads               = false                               {product}
    635      bool UseFPUForSpilling                         = true                                {C2 product}
    636      bool UseFastAccessorMethods                    = false                               {product}
    637      bool UseFastEmptyMethods                       = false                               {product}
    638      bool UseFastJNIAccessors                       = true                                {product}
    639      bool UseFastStosb                              = true                                {ARCH product}
    640      bool UseG1GC                                   = false                               {product}
    641      bool UseGCLogFileRotation                      = false                               {product}
    642      bool UseGCOverheadLimit                        = true                                {product}
    643      bool UseGCTaskAffinity                         = false                               {product}
    644      bool UseHeavyMonitors                          = false                               {product}
    645      bool UseInlineCaches                           = true                                {product}
    646      bool UseInterpreter                            = true                                {product}
    647      bool UseJumpTables                             = true                                {C2 product}
    648      bool UseLWPSynchronization                     = true                                {product}
    649      bool UseLargePages                             = false                               {pd product}
    650      bool UseLargePagesInMetaspace                  = false                               {product}
    651      bool UseLargePagesIndividualAllocation        := false                               {pd product}
    652      bool UseLockedTracing                          = false                               {product}
    653      bool UseLoopCounter                            = true                                {product}
    654      bool UseLoopInvariantCodeMotion                = true                                {C1 product}
    655      bool UseLoopPredicate                          = true                                {C2 product}
    656      bool UseMathExactIntrinsics                    = true                                {C2 product}
    657      bool UseMaximumCompactionOnSystemGC            = true                                {product}
    658      bool UseMembar                                 = false                               {pd product}
    659      bool UseMultiplyToLenIntrinsic                 = true                                {C2 product}
    660      bool UseNUMA                                   = false                               {product}
    661      bool UseNUMAInterleaving                       = false                               {product}
    662      bool UseNewLongLShift                          = false                               {ARCH product}
    663      bool UseOSErrorReporting                       = false                               {pd product}
    664      bool UseOldInlining                            = true                                {C2 product}
    665      bool UseOnStackReplacement                     = true                                {pd product}
    666      bool UseOnlyInlinedBimorphic                   = true                                {C2 product}
    667      bool UseOptoBiasInlining                       = true                                {C2 product}
    668      bool UsePSAdaptiveSurvivorSizePolicy           = true                                {product}
    669      bool UseParNewGC                               = false                               {product}
    670      bool UseParallelGC                            := true                                {product}
    671      bool UseParallelOldGC                          = true                                {product}
    672      bool UsePerfData                               = true                                {product}
    673      bool UsePopCountInstruction                    = true                                {product}
    674      bool UseRDPCForConstantTableBase               = false                               {C2 product}
    675      bool UseRTMDeopt                               = false                               {ARCH product}
    676      bool UseRTMLocking                             = false                               {ARCH product}
    677      bool UseSHA                                    = false                               {product}
    678      bool UseSHA1Intrinsics                         = false                               {product}
    679      bool UseSHA256Intrinsics                       = false                               {product}
    680      bool UseSHA512Intrinsics                       = false                               {product}
    681      intx UseSSE                                    = 4                                   {product}
    682      bool UseSSE42Intrinsics                        = true                                {product}
    683      bool UseSerialGC                               = false                               {product}
    684      bool UseSharedSpaces                           = false                               {product}
    685      bool UseSignalChaining                         = true                                {product}
    686      bool UseStoreImmI16                            = false                               {ARCH product}
    687      bool UseStringDeduplication                    = false                               {product}
    688      bool UseSuperWord                              = true                                {C2 product}
    689      bool UseTLAB                                   = true                                {pd product}
    690      bool UseThreadPriorities                       = true                                {pd product}
    691      bool UseTypeProfile                            = true                                {product}
    692      bool UseTypeSpeculation                        = true                                {C2 product}
    693      bool UseUTCFileTimestamp                       = true                                {product}
    694      bool UseUnalignedLoadStores                    = false                               {ARCH product}
    695      bool UseVMInterruptibleIO                      = false                               {product}
    696      bool UseXMMForArrayCopy                        = true                                {product}
    697      bool UseXmmI2D                                 = false                               {ARCH product}
    698      bool UseXmmI2F                                 = false                               {ARCH product}
    699      bool UseXmmLoadAndClearUpper                   = true                                {ARCH product}
    700      bool UseXmmRegToRegMoveAll                     = true                                {ARCH product}
    701      bool VMThreadHintNoPreempt                     = false                               {product}
    702      intx VMThreadPriority                          = -1                                  {product}
    703      intx VMThreadStackSize                         = 0                                   {pd product}
    704      intx ValueMapInitialSize                       = 11                                  {C1 product}
    705      intx ValueMapMaxLoopSize                       = 8                                   {C1 product}
    706      intx ValueSearchLimit                          = 1000                                {C2 product}
    707      bool VerifyMergedCPBytecodes                   = true                                {product}
    708      bool VerifySharedSpaces                        = false                               {product}
    709      intx WorkAroundNPTLTimedWaitHang               = 1                                   {product}
    710     uintx YoungGenerationSizeIncrement              = 20                                  {product}
    711     uintx YoungGenerationSizeSupplement             = 80                                  {product}
    712     uintx YoungGenerationSizeSupplementDecay        = 8                                   {product}
    713     uintx YoungPLABSize                             = 4096                                {product}
    714      bool ZeroTLAB                                  = false                               {product}
    715      intx hashCode                                  = 5                                   {product}
    716 java version "1.8.0_45"
    717 Java(TM) SE Runtime Environment (build 1.8.0_45-b14)
    718 Java HotSpot(TM) 64-Bit Server VM (build 25.45-b02, mixed mode)

## 2.5、各区域内存大小设置 ##

注：虚拟机启动时就会把参数中设定大小的内存全部划为私有，即使扩容前有一部分内存不会被用户代码用到，这部分内存也不会交给其他进程使用。

**2.5.1、方法区**

永久代（Java8之前，Java8中没有永久代概念，下面参数无效）

\-XX:PermSize=256m：设置永久代初始值为256M。

\-XX:MaxPermSize=256m：设置永久代最大值为256M。（同上）

元空间（Java8中）

\-XX:MetaspaceSize，初始空间大小，达到该值就会触发垃圾收集器进行类型卸载，同时GC会对该值进行调整：如果释放了大量的空间，就适当降低该值；如果释放了很少的空间，那么在不超过MaxMetaspaceSize时，适当提高该值

\-XX:MaxMetaspaceSize，最大空间，默认没有限制。

**2.5.2、栈**

\-Xss128k：设置每个线程的栈大小。JDK5.0以后每个线程栈大小为1M，之前每个线程栈大小为256K。应当根据应用的线程所需内存大小进行调整。在相同物理内存下，减小这个值能生成更多的线程。但是操作系统对一个进程内的线程数还是有限制的，不能无限生成，经验值在3000~5000左右。需要注意的是：当这个值被设置的较大（例如>2MB）时将会在很大程度上降低系统的性能。

**2.5.3、堆**

\-Xmx3550m：等价于-XX:MaxHeapSize，设置JVM最大堆内存为3550M。

\-Xms3550m：等价于-XX:InitialHeapSize，设置JVM初始堆内存为3550M。此值可以设置与-Xmx相同，以避免每次垃圾回收完成后JVM重新分配内存。

\-Xmn2g：设置年轻代大小为2G。在整个堆内存大小确定的情况下，增大年轻代将会减小年老代，反之亦然。此值关系到JVM垃圾回收，对系统性能影响较大，官方推荐配置为整个堆大小的3/8。

\-XX:NewSize=1024m：设置年轻代初始值为1024M。

\-XX:MaxNewSize=1024m：设置年轻代最大值为1024M。

\-XX:SurvivorRatio=4：设置年轻代中Eden区与一个Survivor区的比值。表示Edgen为一个Survivor的4倍，即1个Survivor区占整个年轻代大小的1/6。

\-XX:NewRatio=4：设置老年代与年轻代（包括1个Eden和2个Survivor区）的比值。表示老年代是年轻代的4倍。

\-XX:PretenureSizeThreadshold=1024：设置让大于此阈值的对象直接分配在老年代（只对Serial、ParNew收集器有效），单位为字节

\-XX:MaxTenuringThreshold=7：

表示一个对象如果在Survivor区移动了7次那下次MinorGC时就进入老年代。如果设置为0的话，则年轻代对象不经过Survivor区，直接进入年老代，对于需要大量常驻内存的应用，这样做可以提高效率。如果将此值设置为一个较大值，则年轻代对象会在Survivor区进行多次复制，这样可以增加对象在年轻代存活时间，增加对象在年轻代被垃圾回收的概率，减少Full GC的频率，可以在某种程度上提高服务稳定性。

\-XX:+PrintTenuringDistribution：让JVM在每次MinorGC后打印出当前使用的Survivor中对象的年龄分布。示例：

Desired survivor size 75497472 bytes, new threshold 15 (max 15)
    - age   1:   19321624 bytes,   19321624 total
    - age   2:      79376 bytes,   19401000 total
    - age   3:    2904256 bytes,   22305256 total

第一行显示Survivor容量及对象被移到老年代的年龄阈值。

第二行起，每行显示当前Survivor中某个年龄下对象的大小及小于等于该年龄的对象大小总和。因为目前Survivor空间中对象的大小22M小于期望Survivor空间的大小72M，所以没有对象会被移到老年代。

假设下一次MinorGC后的输出结果为：

Desired survivor size 75497472 bytes, new threshold 2 (max 15)
    - age   1:   68407384 bytes,   68407384 total
    - age   2:   12494576 bytes,   80901960 total
    - age   3:      79376 bytes,   80981336 total
    - age   4:    2904256 bytes,   83885592 total

上次MinorGC后还存活的对象在这次MinorGC年龄都增加了1，可以看到上次年龄为2和3的对象（对应在这次GC后的年龄为3和4）依然存在（大小未变），而一部分上次对象年龄为1的对象在这次GC时被回收了。同时可以看到这次新增了约68M的新对象。这次MinorGC后Survivor区域中对象总的大小为约83M，大于了期望的Survivor空间的大小72M，因此它就把对象移到老年代的年龄的阈值调整为2，在下次MinorGC时一部分对象就会被移到老年代了。