On Sat, Jan 04, 2014 at 07:22:32PM +0100, Alexander Gordeev wrote: > Hello, > > This is version 2 of RFC "perf: IRQ-bound performance events". That is an > introduction of IRQ-bound performance events - ones that only count in a > context of a hardware interrupt handler. Ingo suggested to extend this > functionality to softirq and threaded handlers as well:
Did you measure the overhead in workloads that do a lot of interrupts? I assume two WRMSR could be a significant part of the cost of small interrupts. For counting at least it would be likely a lot cheaper to just RDPMC and subtract manually. The cache miss example below is certainly misleading, as cache misses by interrupts are often a "debt", that is they are forced on whoever is interrupted. I don't think that is a good use of this. I guess it can be useful for cycles. -Andi -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
