A method for facilitating input/output (I/O) communication for a processing operation is provided. An interrogate command is obtained by an I/O communications adapter. The interrogate command queries for status information of the processing operation to be provided in an interrogate response. A fixed number of resources and a time allocated to the interrogate command is throttled by pre-allocating the fixed number of resources needed for the interrogate command, and maintaining a timestamp for a interrogate message. The interrogate message is forwarded from the I/O communications adapter to a control unit. If the interrogate response is not received by the I/O communications adapter within a limited timeout period as measured by the timestamp, or if the interrogate message is received while the fixed number of pre-allocated resources are in use, the I/O communications adapter returns a busy response indicating the control unit is busy to prevent overrunning the control unit.