Latency and Jitter tests on QNX

Is there any softwares that are able to measure the latency and the jitter of applications on QNX?

Not really. You have to makeup your own. The think is that what latency and jitter you want to measure… There is no real definition. ISR latency? Context switching? Disk Operation? Memory allocation? etc.

Probably there is some tool in Eclipse, though I do not understand question either :slight_smile:

For example, initalizing a 30ms timer, and then to measure the deviation of this timer if I start other process.

Did you read “tick-tock…” articles at

I would write my own test for this. See you might want to try it with a process of high priority or low priority (that`s where it gets interesting).

I want to make it with both, first with a high priority process, and then with a low priority process. Parallel I want to start continous a process that creates a file with 50 MB and then to delete it. The results of the tests are very interessant for me.

Where shall the file be created? On HD? On a CF card? Or on NOR flash? I think the current QNX IDE driver, although it uses DMA, isn’t the fastest. If you do this test, you are not measuring timer latency/jitter of the QNX Neutrino OS, but of the QNX Neutrino RTOS with the devb-eide driver active. This may be the thing you want to if you real application later needs to respond in time while devb-eide is active. If this is not your use-case, then the test results are not useful.

This is was only a example. My goal is to start a “stress” program, and then to measure the latency/jitter with a low and a high priority timer. It will be very nice when I find an example for this, because I am just starting with QNX and I have no idea how to create real time tasks with it.