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IV87242: INCREASED CPU USAGE DUE TO LOCKING OVERHEAD IN JAVA 8 ON X86 AND SYSTEM Z PLATFORMS

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You can track all active APARs for this component.

 

APAR status

  • Closed as program error.

Error description

  • Error Message: Increased CPU consumed by the jvm to perform java
    lock-related activities in Java 8 and higher releases. A JLM
    profile taken on Java 8 shows an increase in the 'TIER3' column
    of the 'Java (Inflated) Monitors' section. Tprof logs will show
    a large increase in CPU usage due to the following contributors:
    objectMonitorEnterNonBlocking  and objectMonitorEnterBlocking
    .
    Stack Trace: N/A
    .
    See also APAR IV87241  which fixes the issue on system z alone
    

Local fix

Problem summary

  • The performance impact is attributed to an unoptimized compare
    and swap operation being performed in the object monitor locking
    related code.
    

Problem conclusion

  • The jvm has been fixed to optimize the compare and swap
    operation.
    .
    This APAR will be fixed in the following Java Releases:
       8    SR3 FP11  (8.0.3.11)
    .
    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

    IV87242

  • 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

    2016-07-25

  • Closed date

    2016-07-25

  • Last modified date

    2016-09-13

  • 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:
21 February 2022