Hello,
I wish to measure the CPU utlization for a cortex processor running an RTOS (keil RTX). Without an RTOS, i can measure the idle time to come to some conclusion. But with RTOS, can someone guide me how to measure CPU utlization?
Thanks & Best Regards Vivek
Hello Tamir,
Why do you think, this approach wont work in RTX?
Even if RTX is preemptive and doesn't have a fixed window size to execute tasks, I believe, then also this approach could give a measure of CPU idle time. Isnt it?
If i use context switching to save a timer value, then also i need to check for idle task's id etc...and then its just a matter of using a time difference right away instead of using variables.
Am I missing something?
Thanks & Best Regards, Vivek
Vivek,
the fact that the idle task is not executed does not mean the processor is 100% loaded. proof? you can probably add a task that needs to wait for a predetermined period before waking up (even quite often) and it will probably never miss its deadline.
"the fact that the idle task is not executed does not mean the processor is 100% loaded. proof? you can probably add a task that needs to wait for a predetermined period before waking up (even quite often) and it will probably never miss its deadline."
Is that proof?
You can always add a task and have it run without it missing it's deadline so long as the priorities are suitable. (i.e., higher priority than others that are ready to run.)
Those lower priority tasks will still be consuming CPU cycles if they're ready to run.
ok, it's not "proof" - I just wanted to demonstrate that one cannot conclude anything based on idle task.