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Re: Execution time
- From: Nick Garnett <nickg at ecoscentric dot com>
- To: Michele Portolan <micheleportolan at yahoo dot it>
- Cc: ecos-discuss at ecos dot sourceware dot org
- Date: 20 Sep 2006 17:42:36 +0100
- Subject: Re: [ECOS] Execution time
- References: <4510E0ED.7010307@yahoo.it>
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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