Processor interrupt determination procedures are described. In an implementation, one or more computer-readable media comprise instructions that are executable by a computer to determine, based on a performance goal, which of a plurality of processors is to be targeted by a device that is to perform an input/output operation when an interrupt message is discovered that is from the device and that targets the determined processor. The interrupt message is communicated to the device to indicate availability of the determined processor for use by the device. When an interrupt message is discovered that is from the device and that targets an alternative processor near the determined processor when compared with other processors in the plurality of processors, the interrupt message that targets the alternative processor is communicated to the device to indicate availability of the alternative processor for use by the device.