Executable gives different FPS values ​in Yocto and Raspbian(everything looks the same in terms of configuration)

Question

In Yocto project, built my project which is running on Raspbian OS. When i run executable, i get half FPS compared to executable running on Raspbian OS.

The libraries i use:

• OpenCV
• Tensorflow-Lite, Flatbuffer, Libedgetpu

I use Libedgetpu1-std, Tensorflow-lite 2.4.0 on Raspbian and Libedgetpu 2.5.0, Tensorflow-lite 2.5.0 on Yocto.

Thinking that the problem is that the versions or configurations of the libraries are not the same, i followed these steps:

I ran the executable which i built in Raspbian directly in the runtime of the Yocto project.(I have set the required library versions to the same library versions available in raspbian for it to work in runtime.)

But i still got low FPS. Here is how i calculate that i get half the FPS:

I am using TFLite's interpreter invoke function. I set a timer when entering and exiting the function, i calculate FPS over it. I can exemplify like this:

Timer_Begin();
m_tf_interpreter->Invoke();
Timer_End();

Somehow i think the Interpreter Invoke function is running slower on the Yocto side. I checked Kernel versions, CPU speeds, /boot/config.txt contents, USB power consumes of Raspbian and Yocto. However, I couldn't catch anything from anywhere.

Note : Using RPI4 and Coral-TPU(Plugged into USB 2.0).

Answer 1

We spoke with @Paulo Neves. He recommend Perf profiling and i did . In the perf profiling, i noticed that the CPU is running slowly. Although the frequencies are the same.

When i check the "scaling_governor", i saw that it was in "powersave" mode. The problem solved when i switched from "powersave" to "performance" mode from virtual kernel.

In addition, if you want to make the governor change permanent, you need to create a kernel config fragment.