Experimental options in official builds ?

[Kirk Pepperdine]

this is normal
-- Kirk
On 2013-10-02, at 6:27 PM, Pierre Laporte <pierre at pingtimeout.fr> wrote:

> Hi guys
> 
> I just discovered that you can unlock experimental VM options in a regular
> build of the JDK.
> 
> This page<http://www.programmingforliving.com/2013/08/how-to-speed-up-eclipse-sts-startup.html>tells
> that unlocking some experimental features can speed up Spring
> ToolSuite. I made some tests on jdk 1.7.0_25 and 1.7.0_40 on linux machines
> and I can indeed modify experimental flags. I thought that experimental
> flags were only for debug build.
> 
> Is this normal ?
> 
> 
> $ java -XX:+PrintFlagsFinal -version | grep experimental
> java version "1.7.0_40"
> OpenJDK Runtime Environment (IcedTea 2.4.2) (ArchLinux build
> 7.u40_2.4.2-1-x86_64)
> OpenJDK 64-Bit Server VM (build 24.0-b56, mixed mode)
> 
> 
> $ java *-XX:+UnlockExperimentalVMOptions* -XX:+PrintFlagsFinal -version |
> grep experimental
>    uintx ArrayAllocatorMallocLimit                 =
> 18446744073709551615{experimental}
>     intx G1ExpandByPercentOfAvailable              = 20
> {experimental}
>    ccstr G1LogLevel                                =
> {experimental}
>    uintx G1MaxNewSizePercent                       = 60
> {experimental}
>    uintx G1MixedGCLiveThresholdPercent             = 65
> {experimental}
>    uintx G1NewSizePercent                          = 5
> {experimental}
>    uintx G1OldCSetRegionThresholdPercent           = 10
> {experimental}
>     bool G1UseConcMarkReferenceProcessing          = true
> {experimental}
>     bool G1UseParallelRSetScanning                 = true
> {experimental}
>     bool G1UseParallelRSetUpdating                 = true
> {experimental}
>   double ObjectCountCutOffPercent                  = 0.500000
> {experimental}
>     intx PredictedLoadedClassCount                 = 0
> {experimental}
>     bool TrustFinalNonStaticFields                 = false
> {experimental}
> *     bool UnlockExperimentalVMOptions              := true
> {experimental}      *
>     bool UseCriticalCMSThreadPriority              = false
> {experimental}
>     bool UseCriticalCompilerThreadPriority         = false
> {experimental}
>     bool UseCriticalJavaThreadPriority             = false
> {experimental}
>     bool UseMemSetInBOT                            = true
> {experimental}
>    uintx WorkStealingHardSpins                     = 4096
> {experimental}
>     intx WorkStealingSleepMillis                   = 1
> {experimental}
>    uintx WorkStealingSpinToYieldRatio              = 10
> {experimental}
>    uintx WorkStealingYieldsBeforeSleep             = 5000
> {experimental}
> java version "1.7.0_40"
> OpenJDK Runtime Environment (IcedTea 2.4.2) (ArchLinux build
> 7.u40_2.4.2-1-x86_64)
> OpenJDK 64-Bit Server VM (build 24.0-b56, mixed mode)
> 
> 
> $ java *-XX:+UnlockExperimentalVMOptions* -XX:+PrintFlagsFinal *
> -XX:+TrustFinalNonStaticFields* -version | grep experimental
>    uintx ArrayAllocatorMallocLimit                 =
> 18446744073709551615{experimental}
>     intx G1ExpandByPercentOfAvailable              = 20
> {experimental}
>    ccstr G1LogLevel                                =
> {experimental}
>    uintx G1MaxNewSizePercent                       = 60
> {experimental}
>    uintx G1MixedGCLiveThresholdPercent             = 65
> {experimental}
>    uintx G1NewSizePercent                          = 5
> {experimental}
>    uintx G1OldCSetRegionThresholdPercent           = 10
> {experimental}
>     bool G1UseConcMarkReferenceProcessing          = true
> {experimental}
>     bool G1UseParallelRSetScanning                 = true
> {experimental}
>     bool G1UseParallelRSetUpdating                 = true
> {experimental}
>   double ObjectCountCutOffPercent                  = 0.500000
> {experimental}
>     intx PredictedLoadedClassCount                 = 0
> {experimental}
> *     bool TrustFinalNonStaticFields                := true
> {experimental}
>     bool UnlockExperimentalVMOptions              := true
> {experimental}      *
>     bool UseCriticalCMSThreadPriority              = false
> {experimental}
>     bool UseCriticalCompilerThreadPriority         = false
> {experimental}
>     bool UseCriticalJavaThreadPriority             = false
> {experimental}
>     bool UseMemSetInBOT                            = true
> {experimental}
>    uintx WorkStealingHardSpins                     = 4096
> {experimental}
>     intx WorkStealingSleepMillis                   = 1
> {experimental}
>    uintx WorkStealingSpinToYieldRatio              = 10
> {experimental}
>    uintx WorkStealingYieldsBeforeSleep             = 5000
> {experimental}
> java version "1.7.0_40"
> OpenJDK Runtime Environment (IcedTea 2.4.2) (ArchLinux build
> 7.u40_2.4.2-1-x86_64)
> OpenJDK 64-Bit Server VM (build 24.0-b56, mixed mode)
> 
> --
> 
> Pierre Laporte
> @pingtimeout <https://twitter.com/pingtimeout>
> pierre at pingtimeout.fr
> http://www.pingtimeout.fr/