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hi i am working on a statement where i have to measure the interupt
latency in RTLinux. i'm getting rtlinux3.2 free version to work with.
does this patch contain the necessary api's to carry out the execution
of my problem statement or will i have to get the pro version from fsm
labs... thanks
amit


Re: RTLinux
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If you've got the source, you've got all that you need.

Measuring interrupt latency is a matter if recording the
time at the start of the interrupt and recording it again
at the end.   This may be in software, or it may just
be a matter of toggling a GPIO line and watching it
on an oscilloscope.  But you're going to have to
tweak the interrupt handlers to do this.

I would suggest asking FSM Labs directly if they already
support this or not.  They may already have these numbers
for a variety of systems.

--
Darin Johnson


Re: RTLinux
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To be specific, it's a question of measuring the time between
  - the event that causes the interrupt
  - the interrupt being serviced (taking the required action)

It's important to note that the start of the interval is not within the
interrupt: what's of most interest is the time taken for the service routine
to start, and is a function of the longest time the interrupt can be
disabled for any reason anywhere in the code.

It's not an easy thing to measure; it's usually calculated. It's very likely
to be available as a metric, since this is one of the defining metrics of an
RTOS.

Steve
http://www.fivetrees.com



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