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

Paul E. McKenney
2005-06-21T02:02:44Z

On Mon, Jun 20, 2005 at 01:13:32PM -0400, Kristian Benoit wrote:
> We've finally been able to complete a second round of our tests.
> Unfortunately, this has taken much longer than we ever anticipated.
> Without going into too much detail, suffice it to say that we ran into
> problems with each of our intended test configurations. Fortunately,
> the results are that much more interesting and, we hope, more
> accurately illustrate the performance of the approaches being
> compared.

Again, good stuff!

It looks to me that I-PIPE is an example of a "nested OS", with
Linux nested within the I-PIPE functionality. One could take
the RTAI-Fusion approach, but this measurement is of I-PIPE
rather than RTAI-Fusion, right? (And use of RTAI-Fusion might
or might not change these results significantly, just trying to
make sure I understand what these specific tests apply to.)

Also, if I understand correctly, the interrupt latency measured
is to the Linux kernel running within I-PIPE, rather than to I-PIPE
itself. Is this the case, or am I confused?

Thanx, Paul