Need help to measure and tune the latency in Linux RT

Hi,

I have an embedded system running 2.6.33 cross compiled for ARM OMAP
with 1 GHZ uni-processor system.

The application has many threads and processes (around 15 total). In
that 1 thread is time critical and must run every interval confiurable
as 2, 4 or 8 milli sec etc. There is another thread which transfers
Images to a FTP or to HMI etc, whoever requested the image.
With this image transfer enabled my critical process misses the
deadline and timesout. This critical thread is at RR priority 50. I
used a HR timer thread with RR pri 55 to wakeup the critical thread
every 1 milli sec to do the job.
If image transfer is enabled i see that real time thread misses deadlines.

All traffic is flowing on common ethernet connection. Does it affect
in any way ?

How to find out where the kernel is waiting or delaying to schedule
the critical thread even though it is at higher RR priority. How to
measure the latency ?

I am trying to use Oprofile tool, but got some error in cross
compiling. Doesn't these tools add their own latency to the original
problem ?

Any tools ? which one is better. Please provide your input on this.


Regards
Ashoka.  K
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