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VM66405: PEVM66265 ABENDHTT001 AT HCPMNYPP+1686 20/08/17 PTF PECHANGE

A fix is available

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APAR status

  • Closed as program error.

Error description

  • ABENDHTT001 can occur when running with monitor enabled
    on systems with less than 80 configurable cores.
    
    Other abends can also occur, including ABENDVAP002.
    

Local fix

  • N/A
    

Problem summary

  • ****************************************************************
    * USERS AFFECTED: Users of z/VM running on a machine with less *
    *                 than 80 configurable processors with monitor *
    *                 enabled.                                     *
    ****************************************************************
    * PROBLEM DESCRIPTION:                                         *
    ****************************************************************
    * RECOMMENDATION: APPLY PTF                                    *
    ****************************************************************
    Incorrect code in monitor can lead to a number of abend
    conditions in CP when running on a machine with less than 80
    configurable cores.
    
    In several monitor modules, the code uses a static equate to
    control a loop through alternate processor prefix pages.
    This equate corresponds with the z/VM supported limit on the
    maximum number of logical processors.
    
    In VM66265, a new constant was added which is the minimum of the
    z/VM supported limit on the maximum number of logical
    processors, and the partition supported limit on the maximum
    number of cores times the maximum threading level. This
    constant is used to allocate the storage for alternate
    processor prefix pages. When the partition supported
    limit on the number of cores is smaller than the z/VM
    support limit, this can lead the code in monitor to walk past
    the end of the prefix array. This may lead to a variety of
    abend conditions, including ABENDHTT001 and ABENDVAP002.
    

Problem conclusion

  • Monitor code which loops through the alternate processor prefix
    array is updated to use the new constant so that the loop
    control matches the processor storage allocation.
    

Temporary fix

  • *********
    * HIPER *
    *********
    FOR RELEASE VM/ESACP/ESAR710 :
    PREREQ: VM66265
    CO-REQ: NONE
    IF-REQ: NONE
    FOR RELEASE VM/ESA CP/ESA R720 :
    PREREQ: NONE
    CO-REQ: NONE
    IF-REQ: NONE
    

Comments

APAR Information

  • APAR number

    VM66405

  • Reported component name

    VM CP

  • Reported component ID

    568411202

  • Reported release

    710

  • Status

    CLOSED PER

  • PE

    YesPE

  • HIPER

    YesHIPER

  • Special Attention

    NoSpecatt / Xsystem

  • Submitted date

    2020-06-19

  • Closed date

    2020-08-25

  • Last modified date

    2021-06-29

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

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

    UM35719 UM35720

Modules/Macros

  • HCPMNY   HCPMOM   HCPMOT
    

Fix information

  • Fixed component name

    VM CP

  • Fixed component ID

    568411202

Applicable component levels

  • R710 PSY UM35719

       UP20/09/15 P 2101 ­

  • R720 PSY UM35720

       UP20/09/15 P 2101 ­

Fix is available

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Document Information

Modified date:
30 June 2021