Using the IEFUSI step initiation exit

When the IEFUSI exit receives control, one of the parameters that is passed is the region size that was requested for the JOB or EXEC test JCL statement. For a forked address space, this is displayed as 54M. This value comes from the default SWA blocks that are defined in module BPXPRBS. This is the default JCL that is used when creating forked address spaces.

If the IEFUSI exit does not change any of the region limit values, then the region value is propagated from parent to child, overriding the 54M value. If the region limit value is changed, then the region value is not propagated. The value set by the IEFUSI exit is used instead.

If the IEFUSI exit sets a return code indication that the user should not be able to continue, the initiator will try again. An attempt is made to fork the address space again and if the IEFUSI exit sets the same return code, then reason code 0BFC0434 is set and the address space is terminated.

0BFC0434 — issued from module BPXPRJSR
Reason code 0434 - JrJsrint - Internal error from BPXPRJSR

If users are running in the shell, they might see the following message:

FSUM7726 cannot fork - reason code 0bfc0434

Message BPXP005I is written to the job log for the user:

BPXP005I  A fork or  spawn error was encountered.
  Return code 00000070 Reason code 0BFC0434