Return Codes from PURGE

If the purge operation was successful, register 15 contains zeros. Otherwise, register 15 contains one of the following return codes:

Return Code	Meaning
4 (X'04')	Your request to purge I/O requests associated with a given TCB was not honored because that TCB did not point to the job step TCB, while the requester is in problem state.
8 (X'08')	Either you requested an address-space purge operation, but were not in supervisor state, or you requested a data set purge operation, but failed to supply a DEB address in bytes 1, 2, and 3 of the purge parameter list.
20 (X'14')	Another purge request has preempted your request. You might want to reissue your purge request in a time-controlled loop.

Exception: If you set bit 7 in byte 0 of the parameter list to zero, register 15 will contain zeros, regardless of the outcome of the purge operation.