Topic
  • 7 replies
  • Latest Post - ‏2013-10-17T11:32:28Z by wojand
BootItStrong
BootItStrong
2 Posts

Pinned topic Compatible flag in IBM JDK to turn off JDK 7 bytecode verifier

‏2012-09-28T09:50:42Z |
In Sun JDK one can turn off the JDK 7 split bytecode verification (JSR-202) using the flag -XX:-UseSplitVerifier. Need to know the equivalent flag for IBM JDK 7.

Also it would help me if I get the flag for IBM JDK which shows all default flags currently my JVM runtime is using.
Updated on 2013-03-26T14:50:55Z at 2013-03-26T14:50:55Z by SystemAdmin
  • SystemAdmin
    SystemAdmin
    2736 Posts

    Re: Compatible flag in IBM JDK to turn off JDK 7 bytecode verifier

    ‏2012-09-28T11:23:27Z  
    Hi,

    I can't answer the first question, but the following should show the settings the JVM is running with -verbose:sizes will show the what values some (not all) of JVM configurable are set to.

    e.g. java -verbose:size -version shows the following:

    hardillb@bagend ~$ java -verbose:sizes -version
    -Xmca32K RAM class segment increment
    -Xmco128K ROM class segment increment
    -Xmns0K initial new space size
    -Xmnx0K maximum new space size
    -Xms4M initial memory size
    -Xmos4M initial old space size
    -Xmox512M maximum old space size
    -Xmx512M memory maximum
    -Xmr16K remembered set size
    -Xmso256K operating system thread stack size
    -Xiss2K java thread stack initial size
    -Xssi16K java thread stack increment
    -Xss512K java thread stack maximum size
    java version "1.6.0"
    Java(TM) SE Runtime Environment (build pxa6460sr10fp1-20120321_01(SR10 FP1))
    IBM J9 VM (build 2.4, JRE 1.6.0 IBM J9 2.4 Linux amd64-64 jvmxa6460sr10fp1-20120202_101568 (JIT enabled, AOT enabled)
    J9VM - 20120202_101568
    JIT - r9_20111107_21307ifx1
    GC - 20120202_AA)
    JCL - 20120320_01
  • BootItStrong
    BootItStrong
    2 Posts

    Re: Compatible flag in IBM JDK to turn off JDK 7 bytecode verifier

    ‏2012-10-01T07:34:58Z  
    Hi,

    I can't answer the first question, but the following should show the settings the JVM is running with -verbose:sizes will show the what values some (not all) of JVM configurable are set to.

    e.g. java -verbose:size -version shows the following:

    hardillb@bagend ~$ java -verbose:sizes -version
    -Xmca32K RAM class segment increment
    -Xmco128K ROM class segment increment
    -Xmns0K initial new space size
    -Xmnx0K maximum new space size
    -Xms4M initial memory size
    -Xmos4M initial old space size
    -Xmox512M maximum old space size
    -Xmx512M memory maximum
    -Xmr16K remembered set size
    -Xmso256K operating system thread stack size
    -Xiss2K java thread stack initial size
    -Xssi16K java thread stack increment
    -Xss512K java thread stack maximum size
    java version "1.6.0"
    Java(TM) SE Runtime Environment (build pxa6460sr10fp1-20120321_01(SR10 FP1))
    IBM J9 VM (build 2.4, JRE 1.6.0 IBM J9 2.4 Linux amd64-64 jvmxa6460sr10fp1-20120202_101568 (JIT enabled, AOT enabled)
    J9VM - 20120202_101568
    JIT - r9_20111107_21307ifx1
    GC - 20120202_AA)
    JCL - 20120320_01
    Ben thanks for your post but this is not what I was looking for.
    The questions are straight forward:

    1. Who in IBM is responsible to implement http://www.jcp.org/en/jsr/detail?id=202 ? In Oracle JDK for Linux/Solaris/Windows (both x86 and x86_64) we have an option to switch to older (before 1.6) bytecode verifier. The flag to use here is -XX:-UseSplitVerifier.

    What is the equivalent flag for the same in IBM JDK. Isn't IBM JDK 7 is backward compatible to JDK 1.6 and before.

    I have a separate question also now:

    3. Where is the publicly available compatible matrix for IBM and Oracle JDK 7. So that we can understand compatible flags better.
  • SystemAdmin
    SystemAdmin
    2736 Posts

    Re: Compatible flag in IBM JDK to turn off JDK 7 bytecode verifier

    ‏2013-02-01T14:16:09Z  
    I am also interested in reponses for these question. Have you found answers?
  • SystemAdmin
    SystemAdmin
    2736 Posts

    Re: Compatible flag in IBM JDK to turn off JDK 7 bytecode verifier

    ‏2013-02-12T19:23:29Z  
    I am also interested in reponses for these question. Have you found answers?
    As I checked it looks like process of veryfication bytecode in IBM JDK is a little different from Oracle JDK and this flag will not be so usefull as it is in Oracle JDK.
  • SystemAdmin
    SystemAdmin
    2736 Posts

    Re: Compatible flag in IBM JDK to turn off JDK 7 bytecode verifier

    ‏2013-03-26T14:50:55Z  
    For disable verification process you may use -Xverify:none. This option also turns off split bytecode verification.
  • wojand
    wojand
    2 Posts

    Re: Compatible flag in IBM JDK to turn off JDK 7 bytecode verifier

    ‏2013-10-17T11:30:38Z  
    For disable verification process you may use -Xverify:none. This option also turns off split bytecode verification.

    hi,

    This is my answer, not your SystemAdmin! Please don't stealing my knowledge. This is not support from IBM team (who could  not help us in this matter).

  • wojand
    wojand
    2 Posts

    Re: Compatible flag in IBM JDK to turn off JDK 7 bytecode verifier

    ‏2013-10-17T11:32:28Z  
    For disable verification process you may use -Xverify:none. This option also turns off split bytecode verification.

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