Matlab needs su to access TESLA card

Accelerated Computing CUDA CUDA Programming and Performance
1

I have a machine running Ubuntu 10.04 x64 with dual tesla M2070 cards. I installed the 280.13 drivers (through the main TESLA driver page, not the dev drivers) and the 4.0.17 toolkit.

My issue is that matlab cannot see the GPU’s at all unless matlab is run with root privileges. While I can get around this with setuid, I really don’t want multiple users to have complete root access to the system while running a matlab session.

Does anyone know where along the chain the root permissions are required, so I can adjust the file permissions?

Also, when I use nvidia-smi to look at the temperature of the GPUs, it doesn’t report anything. Is this a driver bug or a quirk of the cards?

2

You need to change the permission to the /dev/nvidia*

ls -l /dev/nvidia*
crw-rw-rw- 1 root root 195, 0 Jun 28 16:13 /dev/nvidia0
crw-rw-rw- 1 root root 195, 255 Jun 28 16:13 /dev/nvidiactl

You could use the script in the release notes to create the device entries with the right permissions ( mknod -m 666 /dev/nvidiactl c 195 255 ).

3

Are those permissions you listed the correct ones?

this is what I have currently:

crw-rw-rw- 1 root root 195, 0 2011-08-19 16:47 /dev/nvidia0
crw-rw-rw- 1 root root 195, 1 2011-08-19 16:47 /dev/nvidia1
crw-rw-rw- 1 root root 195, 255 2011-08-19 16:47 /dev/nvidiactl

4

Hey there,

The permissions for /dev/nvidia* look correct to me. Honestly, you might want to open a ticket with MathWorks - God knows they charge enough, I’d hit them up for support.

Pete

5

Okay… so that isn’t the issue…

When I reboot the machine, the entries /dev/nvidia0, /dev/nvidia1, and /dev/nvidiactl do not exist and the only way I have found to make them appear is to run nvidia-smi -q.

Apparently this is what was breaking it before, but I happened to query the cards with nvidia-smi between trying it in matlab and posting the question and didn’t catch the missing entries in /dev.

6

Check the release notes. They contain a script to create the devices at boot time.