zephyr/tests/legacy/benchmark/latency_measure/README.txt

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Title: Latency Measurement
Description:
This benchmark measures the latency of selected capabilities of both the
nanokernel and microkernel.
IMPORTANT: The sample output below was generated using a simulation
environment, and may not reflect the results that will be generated using other
environments (simulated or otherwise).
--------------------------------------------------------------------------------
Building and Running Project:
This microkernel project outputs to the console. It can be built and executed
on QEMU as follows:
make qemu
--------------------------------------------------------------------------------
Troubleshooting:
Problems caused by out-dated project information can be addressed by
issuing one of the following commands then rebuilding the project:
make clean # discard results of previous builds
# but keep existing configuration info
or
make pristine # discard results of previous builds
# and restore pre-defined configuration info
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Sample Output:
|-----------------------------------------------------------------------------|
| Nanokernel Latency Benchmark |
|-----------------------------------------------------------------------------|
| tcs = timer clock cycles: 1 tcs is N nsec |
|-----------------------------------------------------------------------------|
| 1- Measure time to switch from fiber to ISR execution |
| switching time is NNNN tcs = NNNNN nsec |
|-----------------------------------------------------------------------------|
| 2- Measure time to switch from ISR back to interrupted fiber |
| switching time is NNNN tcs = NNNNN nsec |
|-----------------------------------------------------------------------------|
| 3- Measure time from ISR to executing a different fiber (rescheduled) |
| switching time is NNNN tcs = NNNNN nsec |
|-----------------------------------------------------------------------------|
| 4- Measure average context switch time between fibers |
| Average context switch time is NNNN tcs = NNNNN nsec |
|-----------------------------------------------------------------------------|
| 5- Measure average time to lock then unlock interrupts |
| 5.1- When each lock and unlock is executed as a function call |
| Average time for lock then unlock is NNNN tcs = NNNN nsec |
| |
| 5.2- When each lock and unlock is executed as inline function call |
| Average time for lock then unlock is NNN tcs = NNNN nsec |
|-----------------------------------------------------------------------------|
|-----------------------------------------------------------------------------|
| Microkernel Latency Benchmark |
|-----------------------------------------------------------------------------|
| tcs = timer clock cycles: 1 tcs is N nsec |
|-----------------------------------------------------------------------------|
| 1- Measure time to switch from ISR to back to interrupted task |
| switching time is NNNN tcs = NNNNN nsec |
|-----------------------------------------------------------------------------|
| 2- Measure time from ISR to executing a different task (rescheduled) |
| switch time is NNNNN tcs = NNNNNN nsec |
|-----------------------------------------------------------------------------|
| 3- Measure average time to signal a sema then test that sema |
| Average semaphore signal time NNNNN tcs = NNNNNN nsec |
| Average semaphore test time NNNNN tcs = NNNNNN nsec |
|-----------------------------------------------------------------------------|
| 4- Measure average time to lock a mutex then unlock that mutex |
| Average time to lock the mutex NNNNN tcs = NNNNNN nsec |
| Average time to unlock the mutex NNNNN tcs = NNNNNN nsec |
|-----------------------------------------------------------------------------|
| 5- Measure average context switch time between tasks using (task_yield) |
| Average task context switch using yield NNNNN tcs = NNNNNN nsec |
|-----------------------------------------------------------------------------|
| E N D |
|-----------------------------------------------------------------------------|
===================================================================
PROJECT EXECUTION SUCCESSFUL