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IZ92383: TCP_NODELAYACK CAUSES EAGAIN ERROR ON SORECEIVE APPLIES TO AIX 7100-00

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

  • If tcp_nodelayack is set on each end of 2 socket pair, it
    could lead to a spurious sorwakeup when a socket is not
    readable, causing the next read on the socket to return
    EAGAIN.
    This is especially true if the socket pair are using the
    loopback
     interface.
    

Local fix

  • disable tcp_nodelayack
    

Problem summary

  • pollset_poll returns back to the application with POLLIN,
    even though the socket is not readable, causing next
    read on the socket to return EAGAIN.
    

Problem conclusion

  • Code is modified to check if the socket is readable before
    awakening the process
    

Temporary fix

Comments

  • 5300-10 - use AIX APAR IZ91031
    5300-11 - use AIX APAR IZ91124
    5300-12 - use AIX APAR IZ91123
    6100-03 - use AIX APAR IZ94543
    6100-04 - use AIX APAR IZ81307
    6100-05 - use AIX APAR IZ94530
    6100-06 - use AIX APAR IZ85844
    7100-00 - use AIX APAR IZ92383
    

APAR Information

  • APAR number

    IZ92383

  • Reported component name

    AIX V7.1

  • Reported component ID

    5765H4000

  • Reported release

    710

  • Status

    CLOSED PER

  • PE

    NoPE

  • HIPER

    NoHIPER

  • Submitted date

    2011-01-17

  • Closed date

    2011-01-17

  • Last modified date

    2013-04-16

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

    IZ81307

  • 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 U833143

       UP11/05/11 I 1000

PTF to Fileset Mapping

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Document Information

Modified date:
16 April 2013