Can't kill an process on GPU

i have an process running on an K80 GPU. Is there an way to stop it with the nvidia tools? I tried all the kill -9 etc. Nothing is killing it.

$uname -a
Linux slurm10 3.16.0-33-generic #44~14.04.1-Ubuntu SMP Fri Mar 13 10:33:29 UTC 2015 x86_64 x86_64 x86_64 GNU/Lin



$nvidia-smi -g 1 
Mon Nov 14 15:46:43 2016       
+------------------------------------------------------+                       
| NVIDIA-SMI 352.79     Driver Version: 352.79         |                       
|-------------------------------+----------------------+----------------------+
| GPU  Name        Persistence-M| Bus-Id        Disp.A | Volatile Uncorr. ECC |
| Fan  Temp  Perf  Pwr:Usage/Cap|         Memory-Usage | GPU-Util  Compute M. |
|===============================+======================+======================|
|   1  Tesla K80           Off  | 0000:07:00.0     Off |                    0 |
| N/A   35C    P0    72W / 149W |   8245MiB / 11519MiB |      0%      Default |
+-------------------------------+----------------------+----------------------+

+-----------------------------------------------------------------------------+
| Processes:                                                       GPU Memory |
|  GPU       PID  Type  Process name                               Usage      |
|=============================================================================|
|    1     18320    C   python                                        8187MiB |

`