[ECOS] Execution time

[Nick Garnett]

Michele Portolan <micheleportolan@yahoo.it> writes:

> I would need to check the execution time of different implementations
> of the same function: is there a simple way to do it?
> I lloked up "tm_basic.cxx", but I think my case is far simpler because
> I have no scheduler (for the moment).
> Thanks anyone,


tm_basic shows the standard way of doing this: execute the test
routine many times in a loop, time the whole thing, and calculate the
time per run: total_time/loop_count .

Timing a single excecution is prone to all sorts of interference from
interrupts, cache effects, pipeline effects, DRAM refresh
etc. Multiple runs helps to minimize the effect of these things.

-- 
Nick Garnett                                 eCos Kernel Architect
http://www.ecoscentric.com            The eCos and RedBoot experts


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