A data processing apparatus has a plurality of processors and a plurality of interrupt interfaces each for handling interrupt requests from a corresponding processor. An interrupt distributor controls routing of interrupt requests to the interrupt interfaces. A shared interrupt request is serviceable by multiple processors. In response to the shared interrupt request, a target interrupt interface issues an interrupt ownership request to the interrupt distributor, without passing the shared interrupt request to the corresponding processor, if it estimates that the corresponding processor is available for servicing the shared interrupt request. The shared interrupt request is passed to the corresponding processor when an ownership confirmation is received from the interrupt distributor indicating that the processor has been selected for servicing the shared interrupt request.