Abstract: The disclosed invention is a method and apparatus for use in handling interrupts in a data processing system where the kernel is preemptible, has real-time scheduling ability, and which supports multithreading and tightly-coupled multiprocessors. The invention more specifically provides a technique for servicing interrupts in a processor by means of kernel interrupt handler threads which service the interrupt from start to finish. For efficiency, the interrupt handler threads do not require a complete context switch unless the interrupt handler thread is blocked. The kernel makes use of preprepared interrupt handler threads for additional efficiency, and these interrupt handler threads are not subjected to inordinate delays caused by the phenomenon of interrupt priority inversion if they do become blocked.