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IV56109: REDUCE CPU FABRIC CHATTER TO AVOID HANG DURING DR EVENTS APPLIES TO AIX 7100-04

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

  • System responds sluggishly or is completely hung.
    
    Multiple CPUs show the following stack as they spin on atomic
    op
    
    pvthread+010E00 STACK:  Ý0000AF28¨.fetch_and_nop+000008 ()
    Ý000DE37C¨dr_mpc_freeze_handler+0000DC ()
    Ý001EACBC¨drp_mpc_handler+00013C () Ý0030C244¨i_softmod+000584
    () Ý00154A14¨flih_util+000260 ()
    

Local fix

Problem summary

  • System responds sluggishly or is completely hung.
    
    Multiple CPUs show the following stack as they spin on atomic
    op
    
    pvthread+010E00 STACK:   0000AF28 .fetch_and_nop+000008 ()
     000DE37C dr_mpc_freeze_handler+0000DC ()
     001EACBC drp_mpc_handler+00013C ()  0030C244 i_softmod+000584
    ()  00154A14 flih_util+000260 ()
    

Problem conclusion

  • Perform an unserialized read of the shared word first and then
    a serialized, atomic read only when the first read indicates a
    value is present.
    

Temporary fix

Comments

  • 6100-09 - use AIX APAR IV55958
    6100-09 - use AIX APAR IV55958
    6100-09 - use AIX APAR IV55958
    7100-03 - use AIX APAR IV55974
    7100-04 - use AIX APAR IV56109
    

APAR Information

  • APAR number

    IV56109

  • Reported component name

    AIX V7.1

  • Reported component ID

    5765H4000

  • Reported release

    710

  • Status

    CLOSED PER

  • PE

    NoPE

  • HIPER

    NoHIPER

  • Submitted date

    2014-02-28

  • Closed date

    2014-02-28

  • Last modified date

    2016-05-10

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

    IV55958

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

Fix information

  • Fixed component name

    AIX V7.1

  • Fixed component ID

    5765H4000

Applicable component levels

  • R710 PSY U863867

       UP15/11/22 I 1000

PTF to Fileset Mapping



Document information

More support for: AIX Enterprise Edition

Software version: 710

Operating system(s): AIX

Reference #: IV56109

Modified date: 10 May 2016