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OA38295: HIGH PAGING OF HIPERSPACE PAGES

A fix is available

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APAR status

  • Closed as program error.

Error description

  • At z/OS 1.12 hiperspace pages may be paged to AUX instead of
    staying in REAL storage on a SWRITE.  RSM issues a SYSEVENT
    DIRECTPO to determine if the pages should go to REAL or
    AUXILIARY storage.  IRARMFP1, entry point IRARMF56, will send to
    REAL if RCEAFC is twice as much as RCEAFCOK, which is too
    restrictive.  This causes excessive hiperspace paging to AUX.
    

Local fix

Problem summary

  • ****************************************************************
    * USERS AFFECTED: All users of z/OS 1.12 (HBB7770) and         *
    *                 above.                                       *
    ****************************************************************
    * PROBLEM DESCRIPTION: Excessive hiperspace paging to AUX can  *
    *                      occur on z/OS 1.12 because hiperspace   *
    *                      pages may be paged to AUX instead of    *
    *                      staying in REAL storage on a SWRITE.    *
    ****************************************************************
    * RECOMMENDATION:                                              *
    ****************************************************************
    RSM issues a SYSEVENT DIRECTPO to determine if a hiperspace
    page should be sent to auxiliary storage or stay in real
    storage.  At z/OS 1.12, entry point IRARMF56 in IRARMFP1, will
    only direct that the pages stay in real storage if RCEAFC is
    twice as much as RCEAFCOK, which is too restrictive and can
    cause excessive hiperspace paging to AUX.
    

Problem conclusion

  • The check in IRARMFP1, entry point IRARMF56, to determine where
    a hiperspace page should be sent has been updated to no longer
    just base the decision on the RCEAFC field.  Pages will now also
    be directed to real storage when the MCVUIC3 and MCVUIC4 fields
    contain more than 10% of the real storage (RCEPOOL).
    

Temporary fix

Comments

APAR Information

  • APAR number

    OA38295

  • Reported component name

    SRM - SYS RSRCE

  • Reported component ID

    5752SC1CX

  • Reported release

    770

  • Status

    CLOSED PER

  • PE

    NoPE

  • HIPER

    NoHIPER

  • Special Attention

    YesSpecatt / Pervasive / Xsystem

  • Submitted date

    2011-12-08

  • Closed date

    2012-02-09

  • Last modified date

    2017-02-07

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

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

    UA64117 UA64118

Modules/Macros

  • IRARMFP1
    

Fix information

  • Fixed component name

    SRM - SYS RSRCE

  • Fixed component ID

    5752SC1CX

Applicable component levels

  • R770 PSY UA64117

       UP12/02/22 P F202

  • R780 PSY UA64118

       UP12/02/22 P F202

Fix is available

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Document Information

Modified date:
07 February 2017