Terminate or cancel the latch holder

If you were not able to resolve the latch contention using methods in Resolve latch contention within the PFS and the contention persists, you may need to terminate or cancel the latch holder. The options are listed in order of possible disruption to the system:

To terminate the task holding the latch, do the following steps:
  1. Issue a MODIFY BPXOINIT,RECOVER=LATCHES console command to resolve the contention. This command can take several minutes to resolve the latch contention, but if the system cannot resolve the latch contention within a reasonable time interval, the system eventually displays action message BPXM057E. If necessary, see that message for further action.

    Note that if successful, the MODIFY BPXOINIT,RECOVER=LATCHES command causes the abend of user tasks or non-critical system tasks that hold latches, generates one or more address space dumps, and can result in the termination of an entire process. Refer to z/OS MVS System Commands before issuing this command.

  2. Issue command MODIFY BPXOINIT,FORCE=pid[.tid] to terminate individual threads in a process. In the command, pid is the decimal form of the process id to be terminated and tid is the hexadecimal form of the thread id to be terminated. See Controlling z/OS® UNIX System Services (z/OS UNIX) in z/OS MVS System Commands.
  3. Cancel the latch holder.
  4. Log off or force off the latch holder.
  5. Use the STOP command to stop the product address space. For example, stop the colony address space that an NFS file system is running in.
  6. If absolutely necessary, cancel the product address space. For example:
    • Cancel the colony address space that an NFS file system is running in.
    • If you think zFS is in an infinite loop, cancel zFS.
See also Problem diagnosis for shared file system.

Sometimes it might be helpful to know about other waiting threads, even if these threads are not holders or waiters of any latch contention. See Analyze the output for other waiting threads for more information.

If you cannot resolve the mount latch contention after using this procedure, search problem reporting data bases for a fix. If no fix exists, contact the IBM® Support Center and supply the SVC dumps if appropriate.

Parent topic: Procedure: Diagnosing and resolving latch contention