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PI12738: WMQ QUEUE MANAGER USE OF LARGE PAGES TO BACK ABOVE THE BAR STORAGE ALLOCATIONS

A fix is available

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APAR status

  • Closed as program error.

Error description

  • APAR is taken to investigate WebSphere MQ use of large pages
    

Local fix

Problem summary

  • ****************************************************************
    * USERS AFFECTED: All users of WebSphere MQ for z/OS Version 7 *
    *                 Release 1 Modification 0.                    *
    ****************************************************************
    * PROBLEM DESCRIPTION: On systems configured with Large Page   *
    *                      Support, each queue manager uses 8Mb of *
    *                      storage from the configured LFAREA      *
    *                      amount.                                 *
    ****************************************************************
    * RECOMMENDATION:                                              *
    ****************************************************************
    During startup a queue manager allocates 8Mb of storage for the
    internal trace table (regardless of whether trace is enabled or
    not).
    This allocation is incorrectly requesting that this storage is
    backed by 1Mb frames, causing each queue manager to reduce the
    amount of Large Page storage (LFAREA) available to other
    applications.
    If insufficient LFAREA is available for the trace table to be
    allocated, the trace table will be backed by 4K frames instead.
    

Problem conclusion

  • The queue manager is changed to explicitly request 4K backed
    storage for the trace table, removing the potential for
    unexpected LFAREA use.
    100Y
    CSQSQC64
    

Temporary fix

Comments

APAR Information

  • APAR number

    PI12738

  • Reported component name

    WMQ Z/OS V7

  • Reported component ID

    5655R3600

  • Reported release

    100

  • Status

    CLOSED PER

  • PE

    NoPE

  • HIPER

    NoHIPER

  • Special Attention

    NoSpecatt / Xsystem

  • Submitted date

    2014-02-28

  • Closed date

    2014-06-05

  • Last modified date

    2014-07-01

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

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

    UI18584

Modules/Macros

  • CSQSQC64
    

Fix information

  • Fixed component name

    WMQ Z/OS V7

  • Fixed component ID

    5655R3600

Applicable component levels

  • R100 PSY UI18584

       UP14/06/27 P F406

Fix is available

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Document Information

Modified date:
01 July 2014