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IV89973: POSSIBLE ASSERTION IN GC WHEN NUMBER OF WORKER THREADS ARE DYNAMICALLY REDUCED

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You can track all active APARs for this component.

 

APAR status

  • Closed as program error.

Error description

  • Error Message: * ** ASSERTION FAILED ** at ParallelGlobalGC.cpp:
    ((false && (walkEnv->_referenceObjectBuffer.isEmpty())))
    .
    Stack Trace: N/A
    .
    

Local fix

  • Fix the number of gc slave threads to a static value using the
    "-Xgcthreads<number>" Java command line option.
    

Problem summary

  • In some cases, when the GC has dynamically reduced the number of
    gc worker threads, the reference object buffers may not be
    properly flushed when a global GC cycle completes. This will
    lead to an assertion from GC. The number of worker threads can
    be adjusted during a concurrent GC cycle, for example in a
    virtualized environment where the number of available hardware
    threads has been reduced.
    

Problem conclusion

  • The GC has been updated to properly flush the buffers at the
    conclusion of the global GC cycle.
    .
    This APAR will be fixed in the following Java Releases:
       7 R1 SR4       (7.1.4.0)
       8    SR3 FP20  (8.0.3.20)
    .
    Contact your IBM Product's Service Team for these Service
    Refreshes and Fix Packs.
    For those running stand-alone, information about the available
    Service Refreshes and Fix Packs can be found at:
               https://www.ibm.com/developerworks/java/jdk/
    

Temporary fix

Comments

APAR Information

  • APAR number

    IV89973

  • Reported component name

    J9 COMMON CODE

  • Reported component ID

    620700127

  • Reported release

    270

  • Status

    CLOSED PER

  • PE

    NoPE

  • HIPER

    NoHIPER

  • Special Attention

    NoSpecatt / Xsystem

  • Submitted date

    2016-10-13

  • Closed date

    2016-10-13

  • Last modified date

    2021-12-06

  • 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

    J9 COMMON CODE

  • Fixed component ID

    620700127

Applicable component levels

  • R270 PSY

       UP

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Document Information

Modified date:
22 February 2022