MIPS, Perf-events: Work with irq_work

This is the MIPS part of the following commit by Peter Zijlstra: - e360adbe29241a0194e10e20595360dd7b98a2b3 irq_work: Add generic hardirq context callbacks Provide a mechanism that allows running code in IRQ context. It is most useful for NMI code that needs to interact with the rest of the system -- like wakeup a task to drain buffers. Perf currently has such a mechanism, so extract that and provide it as a generic feature, independent of perf so that others may also benefit. The IRQ context callback is generated through self-IPIs where possible, or on architectures like powerpc the decrementer (the built-in timer facility) is set to generate an interrupt immediately. Architectures that don't have anything like this get to do with a callback from the timer tick. These architectures can call irq_work_run() at the tail of any IRQ handlers that might enqueue such work (like the perf IRQ handler) to avoid undue latencies in processing the work. For MIPSXX, we need to call irq_work_run() at the tail of the perf IRQ handler as described above.

DCDeng-Cheng Zhu committed 15 years ago