Interrupt Coalescing in Xen with Scheduler Awareness

Whole-system virtualization causes interrupt handling to be much more difficult than that of operating systems running directly on the hardware. In particular, interrupt delivery and handling is crucial for timer accuracy, I/O performance, and CPU efficiency, among other facets of the system. Substantial efforts have been undertaken to improve interrupt performance on virtual machines, including software techniques such as interrupt coalescing that combines multiple interrupts into one, and paravirtualization that reduces the number of interrupts and exceptions in the first place.