performance and rate monotonic related issues

[Salman]

Hi guys,

I'm mapping remote memory segments to local memory using SCI in a
cluster.

My questions are:

1. is there any way, which I can find out for a simple operation (eg a
simple write RemoteMappedAddress = 0;) how many context swicthes,
interrupts, instructions take place? (it should be only one operation,
but I believe dependant on configuration of SCI card it can be variable,
and i'd like to measure it)

2. what's the best way of measuring the latency of such simple operation
? can I use rate monotonic, and decrease period until it time-outs ?

3. when you specify a rate monotonic period (lets say 10 milliseconds),
are these 10 milliseconds purely execution of my task, or do they
include clock ticks and other rate monotonic operations as well?

4. How can I ensure that no interrupt, context switch, task switch, etc
take place while a specific task is running ? can I achieve this but
assigning it a high priority ? or placing it within rate monotonic
period?

Thanks,

Salman