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IV67653: JAVA JIT - HANG OR SLOW COMPILES TIMES.

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You can track all active APARs for this component.

APAR status

  • Closed as program error.

Error description

  • Error Message: Very slow compiles time (possibly as much as
    hours) where a compiler thread is consuming 100% of one CPU, but
    at the same time the JIT verbose shows that the tread is not
    producing new listing output (i.e. it's still working on
    compiling the same method during the time when the hang is
    observed).
    .
    Stack Trace:
    {_ZN17TR_EscapeAnalysis30checkOverlappingLoopAllocationEP7TR_Nod
    eS1_S1_Ri}
    <103 frames total>
    .
    .
    {_ZN17TR_EscapeAnalysis30checkOverlappingLoopAllocationEP7TR_Nod
    eS1_S1_Ri}
    {_ZN17TR_EscapeAnalysis30checkOverlappingLoopAllocationEP7TR_Nod
    eP9Candidate}
    {_ZN17TR_EscapeAnalysis16checkDefsAndUsesEP7TR_NodeP9Candidate}
    {_ZN17TR_EscapeAnalysis16checkDefsAndUsesEv}
    {_ZN17TR_EscapeAnalysis19performAnalysisOnceEv}
    {_ZN17TR_EscapeAnalysis7performEv}
    {_ZN16TR_OptimizerImpl8optimizeEv}
    {_ZN14TR_Compilation20performOptimizationsEv}
    {_ZN14TR_Compilation7compileEv}
    .
    This problem can occur on all platforms.
    

Local fix

  • -Xjit:disableEscapeAnalysis
    This will have a small impact on performance.
    

Problem summary

  • The JIT can spend a long time analysing the bytecodes of a
    method when the bytecodes form a patten that makes it such that
    we have to iterate over the code several times.
    

Problem conclusion

  • The JIT was modified such that it avoids iterating over code
    several times.
    .
    This APAR will be fixed in the following Java Releases:
       6    SR16 FP3  (6.0.16.3)
       6 R1 SR8 FP3   (6.1.8.3)
       7 R1 SR3         (7.1.3.0)
       7    SR8 FP10  (7.0.8.10)
    .
    Contact your IBM Product's Service Team for these Service
    Refreshes and Fix Packs.
    For those running stand-alone, information about the Service
    Refreshes and Fix Packs can be found at:
               https://www.ibm.com/developerworks/java/jdk/
    

Temporary fix

Comments

APAR Information

  • APAR number

    IV67653

  • Reported component name

    JIT

  • Reported component ID

    620700124

  • Reported release

    600

  • Status

    CLOSED PER

  • PE

    NoPE

  • HIPER

    NoHIPER

  • Special Attention

    NoSpecatt

  • Submitted date

    2014-12-08

  • Closed date

    2014-12-08

  • Last modified date

    2015-01-21

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

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

Fix information

  • Fixed component name

    JIT

  • Fixed component ID

    620700124

Applicable component levels

  • R600 PSY

       UP

  • R260 PSY

       UP

  • R130 PSY

       UP



Document information

More support for: Runtimes for Java Technology
Just In Time (JIT) Compiler

Software version: 6.0

Reference #: IV67653

Modified date: 21 January 2015