Re: Priority Inheritance Test (Real-Time Preemption)

Ingo Molnar
2004-11-27T01:36:01Z

* Ingo Molnar <mingo@elte.hu> wrote:

> the additional +1 msec comes from the fact that 1-deep lock/unlock of
> lock1 is an allowed operation too - 2 msec would be the limit if the
> only sequence is the 2-deep one.
>
> so i think the numbers, at least in the 2-deep case, are quite close
> to the theoretical boundary.

in the generic case i think the theoretical boundary should be something
like:

sum(i=1...n)(i) == (n+1) * n / 2

n=1 limit=1
n=2 limit=3
n=3 limit=6
n=4 limit=10

this is quite close to what you have measured for n=1,2,3, and i think
it's becoming exponentially harder to trigger the worst-case with higher
N, so the measured results will likely be lower than that.

Ingo