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IV98975: STAGGER MTRC BUFFERS TO AVOID PTEG COLLISIONS APPLIES TO AIX 7200-02

A fix is available

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You can track all active APARs for this component.

 

APAR status

  • Closed as program error.

Error description

  • On a system with large number of CPUs and relatively low
    maximum memory, PTEs for MTRC buffers might collide on the
    same PTEGs resulting in frequent PTE evictions.
    

Local fix

Problem summary

  • On a system with large number of CPUs and relatively low
    maximum memory, PTEs for MTRC buffers might collide on the
    same PTEGs resulting in frequent PTE evictions.
    

Problem conclusion

  • Stagger the start of MTRC buffers such that the PTEs are spread
    across Hardware Page Table to minimize PTEG collisions.
    

Temporary fix

Comments

  • 6100-09 - use AIX APAR IV99018
    6100-09 - use AIX APAR IV99018
    7100-05 - use AIX APAR IV99184
    7100-05 - use AIX APAR IV99184
    7200-02 - use AIX APAR IV98975
    

APAR Information

  • APAR number

    IV98975

  • Reported component name

    AIX V7.2

  • Reported component ID

    5765CD200

  • Reported release

    720

  • Status

    CLOSED PER

  • PE

    NoPE

  • HIPER

    NoHIPER

  • Submitted date

    2017-08-14

  • Closed date

    2017-08-14

  • Last modified date

    2018-09-21

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

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

    IV99018 IV99102 IV99184

Fix information

  • Fixed component name

    AIX V7.2

  • Fixed component ID

    5765CD200

Applicable component levels

  • R720 PSY U878550

       UP17/10/30 I 1000

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Document Information

Modified date:
10 September 2025