Operating system-managed interrupt steering in multiprocessor systems

An operating system is provided in which an interrupt router dynamically steers each interrupt to one or more processors within set of processors based on overall load information from the set of processors. An interrupt source is assigned to a processor based on the load imposed by the interrupt source and the target overall load for the processor. For example, each processor can maintain information about each interrupt it processes over time. The operating system receives this historical load information to determine an expected load for interrupts of a given type from a given device, an overall load on the system, and a target load for each processor. Given a set of interrupt sources, their expected loads, and target load for each processor, each interrupt source can be assigned dynamically to a processor during runtime of the system. On a regular basis, these assignments can be changed given current operating conditions of the system.