Hi @karim !
How would it be possible to know which physical core is used ? Either the cortex-A72 or A53 ?
To find out to which processor a process is assigned, you can use htop or ps: linux - How to get all processes running on each CPU core in Ubuntu? - Unix & Linux Stack Exchange.
And, from the device tree, you can find the CPU index of each core: imx8qm.dtsi « freescale « dts « boot « arm64 « arch - linux-toradex.git - Linux kernel for Apalis, Colibri and Verdin modules
Do you know if a tool exists to monitor the GPU usage ?
NXP makes the gputop available. Please check: Imx8mm gputop tool.
Also, this article might be of your interest: 2D/3D Graphics Acceleration (GPU) | Toradex Developer Center
Best regards,