On Sat, 2012-03-10 at 06:53 -0500, Mark Hounschell wrote: > > > > Does ksoftirqd deliver timer signals in vanilla? Sometimes :-) Softirqs in vanilla run in interrupt context. Mostly on return from an hardware interrupt handler, the softirqs are called and run anytime interrupts are enabled (and bottom halves enabled). But if there's too much work to do from the soft interrupt, then it pushes the rest of the work to ksoftirqd. Which on vanilla runs as a normal SCHED_OTHER task. In -rt, the hardware handlers are run as thread, and all softirqs are handled by ksoftirqd. -rt does not process any softirqs in interrupt context. The answer to your question is, the timerd softirq runs mostly from interrupt context, which will preempt your high priority CPU hog, but if too much work is being done, it may defer it to ksoftirqd, where your thread might block it. But chances are it wont. -- Steve -- To unsubscribe from this list: send the line "unsubscribe linux-rt-users" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
