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

[Ingo Molnar <mingo@elte.hu>]

* Karim Yaghmour <karim@opersys.com> wrote:

> Ingo Molnar wrote:
> > please retest using recent (i.e. today's) -RT kernels. There were a
> > whole bunch of fixes that could affect these numbers.
> 
> At this point, we're bound to rerun some of the tests. But there's 
> only so many times that one can claim that such and such test isn't 
> good enough because it doesn't have all the latest bells and whistles.  
> Surely there's more to this overhead than just rudimentary bugfixes.

well, it was your choice to benchmark ADEOS against PREEMPT_RT, right?  
You posted numbers that showed your project in a favorable light while 
the PREEMPT_RT numbers were more than 100% off. Your second batch of 
numbers showed a tie, but we still dont know the true correct PREEMPT_RT
irq latency values on your hardware, because your testing still had
bugs. So a minimum requirement would be to post accurate numbers - you 
have started this after all.

this thread showcases one of the many reasons why 'vendor sponsored 
benchmarking' is such a bad idea. I wont post benchmark numbers 
comparing PREEMPT_RT to 'other' realtime projects. I'm obviously biased, 
everyone else sees me as biased, so what's the point? Should i pretend 
i'm not biased towards the stuff i wrote? That would be hypocritical 
beyond recognition. I dont benchmark PREEMPT_RT against other projects 
because i know it perfectly well that it is the best thing since sliced 
bread ;)

	Ingo