Why does nvidia-smi shows process name as "-" and doesn't allow me to kill -9 its PID?

Question

When I enter nvidia-smi, I get the following result:

kill -9 25585 will not work, and instead, I have to ps -ef and kill every python process for the Nvidia GPU to free up. Before, it used to show the actual process name

Can someone please explain why and help not have to do this every time?

Answer 1

I encountered this problem when I ctrl+Z a python process, and I found the solution in the answer to What if 'kill -9' does not work?. It may be a zombie process, find the parent process by

ps -Al|grep xxx (xxx is the pid number of the zombie process)

you will see

0 Z  xxx xxx xxx  0  80   0 -     0 exit   ?        00:00:00 soffice.bin <defunct>

the third xxx is the parent process, and kill it (If it is 1, don't kill it!).