IBM Support

IV49664: SLOW CLASS UNLOADING SCAN TIME

Subscribe

You can track all active APARs for this component.

 

APAR status

  • Closed as program error.

Error description

  • Error Message: When performing class unloading the scan time is
    non linear.
    .
    Stack Trace: N/A
    .
    Using -Xgc:verboseExtensions will show a breakdown of class
    unloading time in the verbose GC log
    

Local fix

  • Use -Xgc:classUnloadingKickoffThreshold=<number> to specify the
    number of classes to be available for unloading to kick off a
    Global GC earlier, this will reduce the impact of the class
    unloading time.
    

Problem summary

  • The problem is caused by an inefficient algorithm used during
    class unloading.
    

Problem conclusion

  • This behaviour is fixed in
    
    6.0.1 SR7
    7.0.0 SR6
    
    The JVM has been updated to use a more efficient algorithm
    during class unloading.
    

Temporary fix

Comments

APAR Information

  • APAR number

    IV49664

  • 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

    2013-09-19

  • Closed date

    2013-10-08

  • Last modified date

    2014-05-30

  • 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

[{"Business Unit":{"code":"BU059","label":"IBM Software w\/o TPS"},"Product":{"code":"SSNVBF","label":"Runtimes for Java Technology"},"Platform":[{"code":"PF025","label":"Platform Independent"}],"Version":"6.1","Line of Business":{"code":"LOB36","label":"IBM Automation"}}]

Document Information

Modified date:
21 February 2022