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IV64215: FCA_ERR6 THAT DECODES TO NO FREE CMD MIGHT HANG SOME PROCESSES APPLIES TO AIX 7100-02

A fix is available

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APAR status

  • Closed as program error.

Error description

  • In certain cases when the FCA_ERR6 decodes to "No free
    cmd to respond to unsolicited ELS";
    there are instances where some of the processes will
    hang.
    The reason for the hang is that there is
    timing window that causes us not to wake up a thread.
    When pdump.sh
    is run against the hanging thread, this might be the
    stack trace
    [000D78F0]e_block_thread+000290 ()
    [000D8548]e_sleep_thread+0000E8 (??, ??, ??)
    [00014F50].kernel_add_gate_cstack+000030 ()
    [043B3B3C]efsc_send_sequence+0007BC (??, ??, ??, ??, ??,
    ??, ??, ??)
    [04355C00]efsc_send_payld+0004E0 (??, ??, ??)
    [04362DC4]efsc_ioctl+000564 (??, ??, ??, ??, ??, ??)
    [0056DA80]rdevioctl+0000C0 (??, ??, ??, ??, ??, ??)
    [00746480]spec_ioctl+000080 (??, ??, ??, ??, ??, ??)
    [0059E750]vnop_ioctl+000050 (??, ??, ??, ??, ??, ??)
    [005B40DC]vno_ioctl+00009C (??, ??, ??, ??, ??)
    [00688C78]common_ioctl+0000F8 (??, ??, ??, ??)
    
    This hang occurs on LPARS that have the Emulex adapter.
    The side effect of this is sometime the LPM might hang
    

Local fix

  • There is no workaround except reboot the LPAR
    

Problem summary

  • 1) errpt indicates
        FCA_ERR6      No free cmd to respond to unsolicited ELS
    2) The reason for condition 1 is because the active cmd linked
       list has
        head = null
        tail = non-null
    3) The reason for condition 2 is because the linked list is
        corrupted because we have issued a command twice
    4) The reason for condition 3 is the timing window
    
    efc driver of ioctls may hang with
    stack
    
    pvthread+015900 STACK:
     000D78F0 e_block_thread+000290 ()
     000D8548 e_sleep_thread+0000E8 (??, ??, ??)
     00014F50 .kernel_add_gate_cstack+000030 ()
     043B3B3C efsc_send_sequence+0007BC
     04355C00 efsc_send_payld+0004E0 (??, ??, ??)
     04362DC4 efsc_ioctl+000564 (??, ??, ??, ??, ??, ??)
     0056DA80 rdevioctl+0000C0 (??, ??, ??, ??, ??, ??)
     00746480 spec_ioctl+000080 (??, ??, ??, ??, ??, ??)
     0059E750 vnop_ioctl+000050 (??, ??, ??, ??, ??, ??)
     005B40DC vno_ioctl+00009C (??, ??, ??, ??, ??)
     00688C78 common_ioctl+0000F8 (??, ??, ??, ??)
     00003850 ovlya_addr_sc_flih_main+000130 ()
     kdb_get_virtual_memory  no real storage @ 2FF221C8
     D0130EF4 D0130EF4 ()
     kdb_read_mem  no real storage @ FFFFFFFFFFF91B0
    

Problem conclusion

  • Code corrected to avoid the timing hole.
    

Temporary fix

Comments

  • 6100-08 - use AIX APAR IV60834
    6100-09 - use AIX APAR IV60904
    6100-09 - use AIX APAR IV60904
    6100-09 - use AIX APAR IV60904
    7100-02 - use AIX APAR IV64215
    7100-03 - use AIX APAR IV60908
    7100-04 - use AIX APAR IV61120
    

APAR Information

  • APAR number

    IV64215

  • Reported component name

    AIX V7.1

  • Reported component ID

    5765H4000

  • Reported release

    710

  • Status

    CLOSED PER

  • PE

    NoPE

  • HIPER

    NoHIPER

  • Submitted date

    2014-08-29

  • Closed date

    2014-08-29

  • Last modified date

    2016-05-11

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

    IV60834

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

    010PC2Ÿ

Fix information

  • Fixed component name

    AIX V7.1

  • Fixed component ID

    5765H4000

Applicable component levels

  • R710 PSY U867211

       UP15/01/19 I 1000

PTF to Fileset Mapping



Document information

More support for: AIX Enterprise Edition

Software version: 710

Operating system(s): AIX

Reference #: IV64215

Modified date: 11 May 2016