Patent ID: 8055817

Claim:
A computer program product for handling of queued-direct input/output (QDIO) requests at an adapter in communication with an I/O device, the computer program product comprising: a storage medium readable by a processing circuit and storing instructions for execution by the processing circuit for implementing a method, the method comprising: accessing a queue comprising one or more storage block address lists (SBALs), each SBAL comprised of a plurality of storage block address list entries (SBALEs) and associated with a storage list status block (SLSB); reading an SBAL count in one of the SBALEs, the SBAL count indicating a number of the SBALs forming an I/O request to the I/O device; and in response to determining that the SBAL count is greater than one, prefetching a number of the SBALs from the queue and associated SLSBs equivalent to the SBAL count without waiting for a notification of completion of each of the SBALs forming the I/O request, and transitioning states of the associated SLSBs from adapter-owned to program-owned.