Re: Priority Inheritance Test (Real-Time Preemption)

Esben Nielsen
2004-11-27T00:20:16Z

On Thu, 25 Nov 2004, Ingo Molnar wrote:

> [...]
> there's one thing i noticed, now that the blocker device is in the
> kernel, you have to be really careful to compile the userspace loop()
> code via the same gcc flags as the kernel did. Minor differences in
> compiler options can skew the timing calibration.
>
> but any such bug should at most cause a linear deviation via a constant
> factor multiplication, while the data shows a systematic nonlinear
> transformation.
>
-g -Wall -O2 was on in userspace.

> [...]
> yeah, i agree that this has to be further investigated. What type of box
> did you test it on - UP or SMP? (SMP scheduling of RT tasks only got
> fully correct in the very latest -31-7 kernel.)
>
UP, PIII 697.143 Mhz

> Ingo
>

Esben