Re: PREEMPT_RT benchmark

Hi Daniel,
Thanks for your answer! That was the problem!
If I understand correctly  when Cyclictest writes to the
cpu_dma_latency file, the processor does not sleep and remain
full power all the time. Is there any problem writing a RT application
(not a benchmark one) with this trick?
Could it cause any harm to the system?
My idea is to develop a RT application in which I have a scheduled
thread to compute and deliver results in a given time or interval.

Michel

Em qui., 11 de mar. de 2021 às 09:27, Daniel Wagner [off-list ref] escreveu:

Hi Michel,

On 10.03.21 21:07, Michel Macena Oliveira wrote:

quoted

At least that's what I expected, but my latencies are much bigger than
Cyclictest ones.
 From cyclictest I get an average in my computer of  something between
2300 and 2500 nanoseconds.  However, in my application I'm having
something between 47000 and 55000 nanoseconds. As you can see it is
much higher!

I'm not sure of what I'm doing wrong, could you help or suggest something?

Check if your system uses power managment. cyclictest disables the power
management by using the /dev/cpu_dma_latency API.

HTH,
Daniel