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VM64770: PAGED PGMBKS CAN CAUSE LONG LOGOFF FOR LARGE GUEST

A fix is available

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APAR status

  • Closed as program error.

Error description

  • When a guest is logged off it's PGMBKs need to be read in.  If
    the guest is large there is a potential for many PGMBKs being
    read in. The single threaded process of reading in these PGMBKs
    by system can take a long time, delaying other guests from
    running.
    

Local fix

Problem summary

  • ****************************************************************
    * USERS AFFECTED: All z/VM users.                              *
    ****************************************************************
    * PROBLEM DESCRIPTION:                                         *
    ****************************************************************
    * RECOMMENDATION: APPLY PTF                                    *
    ****************************************************************
    Performance delays in system-reset clear operations (including
    logoff) caused by single-threaded read operations for paged-out
    PGMBKs.
    

Problem conclusion

  • A batched read prefetch has been implemented for pageable PGMBKs
    to increase the likelihood a PGMBK is in real storage before it
    is needed by release processing.
    

Temporary fix

Comments

  • ×**** PE15/11/09 FIX IN ERROR. SEE APAR VM65097  FOR DESCRIPTION
    

APAR Information

  • APAR number

    VM64770

  • Reported component name

    VM CP

  • Reported component ID

    568411202

  • Reported release

    630

  • Status

    CLOSED PER

  • PE

    NoPE

  • HIPER

    YesHIPER

  • Special Attention

    NoSpecatt / Xsystem

  • Submitted date

    2015-04-30

  • Closed date

    2015-09-08

  • Last modified date

    2016-03-30

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

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

    UM34582

Modules/Macros

  • CBITABLE CPLOAD   HCPALD   HCPASCBK HCPCBI
    HCPHAM   HCPHDI   HCPHDPBK HCPHPH   HCPHRM   HCPHRU   HCPITRBK
    HCPMDLAT HCPMOT   HCPOM1   HCPPAG   HCPPFP   HCPPFPRQ HCPPPI
    HCPPPIBK HCPPTE   HCPPTF   HCPRSM   HCPRSMBK HCPSXU   MRSTORSG
    

Fix information

  • Fixed component name

    VM CP

  • Fixed component ID

    568411202

Applicable component levels

  • R630 PSY UM34582

       UP16/03/30 P 1601 Ž

Fix is available

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Document Information

Modified date:
30 March 2016