Newbie ?

[Mark Hounschell <dmarkh@cfl.rr.com>]

I/we have an app (heavily threaded) that is an emulation of a proprietary
real-time OS. We have recently ported it to linux. It requires a number of pci
cards that have been designed
to accomodate some of the hardware that this proprietary OS ran on. The linux
drivers for these are mostly complete and working. We have found by way of
interrupt latency/determinism
tests that run under the emulated OS and on the native hardware/proprietary OS
that the determinism numbers we get under the emulation are quite poor compared
to the real/native environment. I'm sure this is no suprise to anyone, even us.
It was expected. In the native
environment from interrupt time to user code start time (latency) we get 60us
with a variance
of 1us (determinism). I know 60us isn't so greate, it was for it's time though,
but the 1us
variance is excelant and what we need. The numbers for the same tests run on a
dual 1.7gz p4 zeon are about 50us latency but the determism depends on alot of
things. If we run the app
in single user mode the variance (determinism) numbers are almost exceptable
(but not really).
They end up around 100us in single user mode. They are 2-45 ms with X running
which is crazy.
A simple move of the mouse causes the numbers to go into never never land. With
no X (run level 3) the numbers are better but still very unexceptable.

Why I am posting is, we want to try rtlinux to see what it gets us. I have
installed the 3.1
version for the 2.4.4 kernel and did the suggested method of making mk.rtl
available to our
makefiles for the app compile. It didn't change anything. I need to figure out
if there is an
easy way to make our app look like real-time to rtlinux. I've looked at the
rtlinux API and
many of the stanard linux calls are available and I assume they are different
but with the
same names. I'm not a C programmer. I'm an old fortran/assembler guy from the
days of this
old proprietary OS. IS there an easy way for me to try rtlinux for this app such
that it doesn't have to be rewritten. What about our drivers that we had to
write for linux? Is there
anything that will have to be done to them? Does one have to be a linux kernel
hacker to make an app run in real-time under rtlinux? Is there an easy way to
test this to see if it's what
we need?

Any help or suggestions appreciated
Thank in advance and sorry for the rambling.

Regards
mark

-- 
Mark Hounschell
dmarkh@cfl.rr.com