Messages in this thread | | | Date | Mon, 13 Jun 2005 07:47:58 +0200 | From | Ingo Molnar <> | Subject | Re: PREEMPT_RT vs ADEOS: the numbers, part 1 |
| |
* Karim Yaghmour <karim@opersys.com> wrote:
> > - 0, p->name, p)) { > > + SA_NODELAY, p->name, p)) { > > printk (KERN_WARNING "%s: irq %d in use, " > > "resorting to polled operation\n", > > p->name, p->irq); > > Thanks for the patch. However, we actually wrote our own driver > requesting the parport int instead of using the one in Linux. We just > wanted to really customize the driver in as much as possible for > benchmarking purposes.
in this case you'll still have to use SA_NODELAY - otherwise you'll get an interrupt thread allocated, whose priority could, depending on the order of IRQ requests, be lower than the priority of some other interrupt threads. In that case not only do scheduling latencies get added to your latency value, but also the worst-case latencies of other IRQ handlers!
Ingo - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
| |