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IV34230: AIX COMPRESSED REFERENCES CANNOT CREATE JAVA HEAP BELOW 4GB

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You can track all active APARs for this component.

 

APAR status

  • Closed as program error.

Error description

  • Error Message: On AIX, Java -Xcompressedrefs -Xmx2816M
    unnecessarily places the heap above 4 GB.  This adversely
    affects performance.
    .
    Stack Trace: N/A
    .
    java -Xcompressedrefs -Xmx2816M -verbose:gc -version
    <?xml version="1.0" ?>
    <verbosegc xmlns="http://www.ibm.com/j9/verbosegc"
    version="R26_Java626_SR4_20121024_1635_B126069_CMPRSS">
    <initialized id="1" timestamp="2012-11-21T12:59:27.239">
      <attribute name="gcPolicy" value="-Xgcpolicy:gencon" />
      <attribute name="maxHeapSize" value="0xb0000000" />
      <attribute name="initialHeapSize" value="0x400000" />
      <attribute name="compressedRefs" value="true" />
      <attribute name="compressedRefsDisplacement" value="0x0" />
      <attribute name="compressedRefsShift" value="0x3" />
    ...
    compressedRefsShift=0x3 indicates that the heap is places
    outside the range 0-4GB.
    

Local fix

  • use -Xaggressive
    

Problem summary

  • The range of usable memory addresses was restricted for
    compatibility with older operating system versions.
    

Problem conclusion

  • This defect will be fixed in:
    6.0.1 SR5
    7.0.0 SR4
    .
    The older operating system versions are not supported in this
    Java version.  The restriction has been removed.
    

Temporary fix

Comments

APAR Information

  • APAR number

    IV34230

  • Reported component name

    J9 COMMON CODE

  • Reported component ID

    620700127

  • Reported release

    260

  • Status

    CLOSED PER

  • PE

    NoPE

  • HIPER

    NoHIPER

  • Special Attention

    NoSpecatt

  • Submitted date

    2013-01-07

  • Closed date

    2013-01-07

  • Last modified date

    2013-01-07

  • 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

  • R260 PSY

       UP

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Document Information

Modified date:
21 February 2022