Re: PREEMPT_RT vs I-PIPE: the numbers, part 2

From: Ingo Molnar
Date: Wed Jun 22 2005 - 12:51:33 EST



* Ingo Molnar <mingo@xxxxxxx> wrote:

>
> * Kristian Benoit <kbenoit@xxxxxxxxxxx> wrote:
>
> > Your analysis is correct, but with 600,000 samples, it is possible
> > that we got 2 peeks (perhaps not maximum), one on the logger and one
> > on the target. So in my point of view, the maximum value is probably
> > somewhere between 55us / 2 and 55us - 7us. And probably closer to 55us
> > / 2.
>
> you could try the LPPTEST kernel driver and testlpp utility i
> integrated into the -RT patchset. It avoids target-side latencies
> almost completely. Especially since you had problems with parallel
> interrupts you should give it a go and compare the results.

correction: logger-side latencies are avoided.

Ingo
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/