IZ73689: 64-BIT JAVA RUNS VERY SLOWLY WHEN JIT CODE CACHE IS FULL

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You can track all active APARs for this component.

APAR status

  • Closed as program error.

Error description

  • Error Message: Running Java 5 or Java 6 on 64-bit platforms, the
    JVM's performance is very bad. Profiling shows that most of the
    CPU time is spent in the interpreter (j9vm26.dll or
    libj9vm26.so) rather than JIT-compiled code. If verbose JIT
    tracing is enabled via the -Xjit:verbose option, messages
    like this will be printed:
    .
    <WARNING: JIT CACHES FULL>
    .
    Stack Trace: N/A
    .
    

Local fix

  • It may be possible to work around this issue using the
    unsupported option -Xjit:codeTotal=131072.
    

Problem summary

  • The problem is caused when the JIT code cache becomes full and
    all loaded classes are in use (and hence cannot be unloaded to
    free up memory). This tends to occur only on 64-bit platforms
    due to the larger volume of cached native code.
    

Problem conclusion

  • This defect will be fixed in:
    6.0.0 SR8
    5.0.0 SR12
    .
    The JIT compiler has been updated to use a different code cache
    size threshold for 64-bit platforms. The code cache is grown
    dynamically so applications that do not require the space will
    not be impacted.
    .
    To obtain the fix:
    Install build 20100402 or later
    

Temporary fix

Comments

APAR Information

  • APAR number

    IZ73689

  • Reported component name

    JAVA 5 JIT

  • Reported component ID

    620500124

  • Reported release

    500

  • Status

    CLOSED PER

  • PE

    NoPE

  • HIPER

    NoHIPER

  • Special Attention

    NoSpecatt

  • Submitted date

    2010-04-01

  • Closed date

    2010-05-12

  • Last modified date

    2010-07-22

  • APAR is sysrouted FROM one or more of the following:

    IZ73637

  • APAR is sysrouted TO one or more of the following:

Fix information

  • Fixed component name

    JAVA 5 JIT

  • Fixed component ID

    620500124

Applicable component levels

  • R500 PSN

       UP



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Document information


More support for:

Runtimes for Java Technology
Just In Time (JIT) Compiler

Software version:

5.0

Reference #:

IZ73689

Modified date:

2010-07-22

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