Method and apparatus for interrupt load balancing for powerPC processors

摘要

Interrupts from an I/O subsystem are first directed to a single processor in a multiple superscalar processor data processing system. If an interrupt load on the processor is sufficiently high, the interrupt is sent (offloaded) to a second specific processor. The process continues throughout all superscalar processors in the data processing system and each processor builds interrupt prediction data corresponding to the interrupt load. A threshold counter may be added to the logic so offloading does not take place until a specified number of interrupts are queued within that specific processor, thus providing a fixed level of prediction data. Some processors may be left out of the offload string so they are not disturbed by an interrupt.