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

Bill Huey
2005-06-23T01:08:39Z

On Wed, Jun 22, 2005 at 09:09:30PM -0400, Karim Yaghmour wrote:
> But I don't want to "fight" Ingo. There would just be no point
> whatsoever with "fighting" with one the best developers Linux
> has. I started my involvement in these recent threads with a
> very clear statement that I was open to being shown wrong in
> having exclusively championed the nanokernel approach in the
> past. I set out to show myself wrong with these tests and
> beside some vague expectations, I truely didn't know what I
> was going to find. I certainly wouldn't have bet a hot-dog on
> preempt_rt coming neck-to-neck with the ipipe on interrupt
> latency ... So yes, in doing so some results I've found aren't

Yeah, but so what ? don't freak out and take all of this so seriously.
It's not like nanokernels are going to disappear when this patch gets
broader acceptance. And who cares if you're wrong ? you ? :) Really,
get a grip man. :)

And, of course, DUH, making a kernel fully preemptive makes it (near)
real time. These aren't unexpected results.

> that nice. But, hell, I didn't invent those results. They are
> there for anyone to repdroduce or contradict. I have no
> monopoly over LMbench, PC hardware, the Linux kernel, or
> anything else used to get those numbers.

Thanks for the numbers, really. I do expect some kind of performance
degradation, but there seems to be triggering some oddities with the
patch that aren't consistent with some of our expectations.

Be patient. :)

bill