IV49476: SYSTEM CRASH WITH DEEP I/O STACK BACKPORT APPLIES TO AIX 7100-01

Obtain the fix for this APAR.

APAR status

• Closed as program error.

Error description

• A system crash with varying stack but always a large number of
  calls to storage layer functions. For example:
  
  00129C74v_lookupx_dr+000074 ()
  ￭00129BA4vm_lookupx_dr+000044 (??, ??, ??, ??, ??)
  ￭000B21A4xmemdma64+000564 (??, ??, ??)
  ￭04214BF8d_map_page_tce+000918 (??, ??, ??, ??, ??)
  ￭042700A8efc_mapdma_iocb+0010E8 (??, ??)
  ￭04277AB8efc_start+000518 (??)
  ￭04278818efc_output+000698 (??, ??)
  ￭04475ED8efsc_start+000698 (??, ??)
  ￭044795D8efsc_strategy+000D98 (??)
  ￭002D2564std_devstrat+000364 (??)
  ￭002D2B90devstrat+000050 (??)
  ￭044BB4B8SCSIDISK_ISSUE_CMD+0001B8 (??, ??)
  ￭044D8A40scsidisk_start_in_progress+000380 (??)
  ￭044E0B10scsidisk_start+0006D0 (??)
  ￭044E39D8scsidisk_strategy+000278 (??)
  ...
  

Local fix

Problem summary

• A system crash with varying stack but always a large number of
  calls to storage layer functions. For example:
  
  00129C74 v_lookupx_dr+000074 ()
   00129BA4 vm_lookupx_dr+000044 (??, ??, ??, ??, ??)
   000B21A4 xmemdma64+000564 (??, ??, ??)
   04214BF8 d_map_page_tce+000918 (??, ??, ??, ??, ??)
   042700A8 efc_mapdma_iocb+0010E8 (??, ??)
   04277AB8 efc_start+000518 (??)
   04278818 efc_output+000698 (??, ??)
   04475ED8 efsc_start+000698 (??, ??)
   044795D8 efsc_strategy+000D98 (??)
   002D2564 std_devstrat+000364 (??)
   002D2B90 devstrat+000050 (??)
   044BB4B8 SCSIDISK_ISSUE_CMD+0001B8 (??, ??)
   044D8A40 scsidisk_start_in_progress+000380 (??)
   044E0B10 scsidisk_start+0006D0 (??)
   044E39D8 scsidisk_strategy+000278 (??)
  ...
  

Problem conclusion

• We added another page to the lowest interrupt level stack, and
  implemented this so that we can easily add more pages and/or
  more levels.
  

Temporary fix

Comments

• 6100-07 - use AIX APAR IV47412
  6100-08 - use AIX APAR IV47073
  7100-01 - use AIX APAR IV49476
  7100-02 - use AIX APAR IV49179
  

APAR Information

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

  IV47073

• 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 U864711

     UP14/02/17 I 1000