PK67128: STORAGE VIOLATION CAUSING DEADLOCK WITH SM_LOCK AND XM_LOCK WHEN TASK HOLDS SM_LOCK ISSUES SET_TRANSACTION AND NEEDS XM_LOCK

Obtain the fix for this APAR.

APAR status

• Closed as program error.

Error description

• DFHSMMF is performing a FREEMAIN and a storage violation is
  detected and storage_check_failure is called. It has the SMLOCK
  and then issues dfhxmiqm function (SET_TRANSACTION) to increment
  the storage violation count in the PCT entry. This requires
  the XMLOCK but another task has the XMLOCK and now wants the
  SMLOCK after it issues, dfhsmgfm function (FREEMAIN) out of
  free_transaction. We need to release and acquire the SMLOCK
  around the SET_TRANSACTION call in DFHSMMF to prevent deadlock.
  

Local fix

Problem summary

• ****************************************************************
  * USERS AFFECTED: All.                                         *
  ****************************************************************
  * PROBLEM DESCRIPTION: Deadlock between two tasks caused by    *
  *                      conflicting XMLOCK and SMLOCK requests. *
  ****************************************************************
  * RECOMMENDATION:                                              *
  ****************************************************************
  There is a deadlock between a transaction that owns the SMLOCK
  and is waiting for the XMLOCK to be freed and another that owns
  the XMLOCK and is waiting for the SMLOCK to be freed.
  
  (1) Following a storage violation, procedure
  storage_check_failure in DFHSMMF is called.  This holds the
  SMLOCK.
  (2) A transaction manager SET_TRANSACTION call is made to
  update the number of storage violations which have occurred for
  the task.  This requires the XMLOCK.
  (3) At the same time a problem has occurred during the attach of
  another task.  This holds the XMLOCK.
  (4) Procedure free_transaction in DFHXMAT is called to make a
  storage manager FREEMAIN call to free storage in the transaction
  subpool.  This requires the SMLOCK.
  
  Additional Keywords: SM XM MSGDFHSM0102 DFHSM0102 SM0102
  

Problem conclusion

• Procedure storage_check_failure in DFHSMMF has been changed to
  release and reacquire the SMLOCK around the transaction manager
  SET_TRANSACTION calls.
  

Temporary fix

•             *********
              * HIPER *
              *********
  FIX AVAILABLE BY PTF ONLY
  

Comments

APAR Information

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

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

  UK40432 UK40433

Modules/Macros

•    DESSMMF  DFHSMMF
  

Fix information

• Fixed component name

  CICSTS V3 Z/OS

• Fixed component ID

  5655M1500

Applicable component levels

• R400 PSY UK40432

     UP08/10/08 P F810

• R500 PSY UK40433

     UP08/10/08 P F810

Fix is available

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