PH08005: DFHDS0004 LOOP IN DFHDSAT WITH MVS GETMAINS & FREEMAINS

Obtain the fix for this APAR.

APAR status

• Closed as program error.

Error description

• During the attach of a new task, DFHDSAT issues message
  .
  DFHDS0004 A possible loop has been detected at offset X'FFFF'
   in module DFHDSAT.
  .
  Kernel error data shows abend 999/AKEC for the task indicating
  a loop was detected in DFHDSAT +x'900'. MVS system trace shows
  a loop of MVS GETMAINs/FREEMAINs from DFHDSAT, acquiring and
  freeing the same storage address.
  .
  Kernel stacks show processing is in the GET_TASK_PAGE routine
  in DFHDSAT. Dispatcher maintains its own page for quick-celled
  DTAs in a PAM (Page Allocation Map). The problem causing the
  loop of MVS GETMAINs/FREEMAINs from DFHDSAT is that the number
  of tasks in the region has grown until there is no more room
  left in the PAM to save the newly GETMAINed page. However,
  DFHDSAT should put out an error instead of loop.
  .
  Additional Symptom(s) Search Keyword(s): KIXREVxxx
  

Local fix

Problem summary

• ****************************************************************
  * USERS AFFECTED: All CICS Users.                              *
  ****************************************************************
  * PROBLEM DESCRIPTION: DFHDSAT loop of getmains and freemains. *
  ****************************************************************
  The loop in DFHDSAT is the result of another problem which
  created a build up of DTAs due to the attach of system
  tasks which were unable to run.
  The upper limit of 5120 DTAs was eventually reached.
  The next attach of a system task tried to acquire a new DTA.
  Dispatcher domain set a bad return pointer because it could not
  allocate a new DTA.
  This return pointer was wrongly interpreted and dispatcher
  tried to acquire a DTA again, which resulted in a loop.
  Keywords: DFHXM0213 msgDFHXM0213
  

Problem conclusion

• Dispatcher domain has been changed to set the return pointer
  correctly.
  

Temporary fix

Comments

APAR Information

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

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

  UI62862 UI62863 UI62864

Modules/Macros

• DFHDSAT  DFHDSDS2 DFHDSSR
  

Fix information

• Fixed component name

  CICS TS Z/OS V5

• Fixed component ID

  5655Y0400

Applicable component levels

• R000 PSY UI62862

     UP19/05/08 P F905

• R100 PSY UI62864

     UP19/05/08 P F905

• R200 PSY UI62863

     UP19/05/08 P F905

Fix is available

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