How works CPU constant mode (when RAPL files are not found) ?

Hello !

I am trying to use CodeCarbon on a Linux virtual machine. I don't have the RAPL module on it so the cpu tracking falls on constant mode.
If I understood well the methodology, in this case the cpu energy consumption = TDP * usage (constante=0,5) ?
If it's true, experimentally, the cpu_energy divided by the duration should be constant between different measures on the same machine. In practice, I made several measures on the same machine which are saved on a .csv, and then I calculated cpu_ernergy/duration on all the lines, I get close values but not equal, do you know why ?

I saw that you began to work on CPU load tracking with psutil, it is not merged yet, right ?
Do you know if it is possible to custom the kernel of a virtual machine so it is able to use RAPL files or it doesn't work on virtual environnements ?

Thank you for your help !

Start by reading the CPU tracking implementation for the constant mode used when RAPL files are unavailable, then compare how CPU energy, duration, and usage are calculated across the reported CSV measurements. Check the status of the mentioned psutil CPU-load work and whether virtual machines can expose RAPL files. Done means the constant-mode behavior and measurement variation are explained or reproduced, with any needed documentation or fix identified.