How to remove /usr/bin/gnome-shell in nvidia-smi?

Hi there,
I have a newly installed Ubuntu system to use for my work.
There is a /usr/bin/gnome-shell process when I use nvidia-smi.
I tried to get rid of it but failed. I looked into this question:

Can anybody tell me what specifically I need to do? I hope to use the GPU only for computing.

Thanks!