[Slackbuilds-users] nvidia-driver CUDA glitch

[Mats Bertil Tegner]

On 2014-07-13 20:18, King Beowulf wrote:
> I just realized a fix for a glitch with the new nvidia-driver and CUDA
> initialization.  Since the slackbuild is already in "approved" and its
> not fatal unless you run CUDA/OpenCL programs, I'll fix this up on the
> next update.  This issue popped up somewhere in the 331.xx drivers.
>
> For those of you, as I do, who run BOINC, or another CUDA program, you
> may have wondered about "no usable GPUs found" message in the BOINC log.
>   Turns out, some weird process in the way Nvidia does things now, since
> the introduction of nvidia-uvm.ko, prevents the creation of a required
> device node unless you first run your CUDA program as "root."  This then
> creates the device node and all is then well as a regular user.  You
> should see:
>
> $ ls -l /dev/nvidia-uvm
> crw-rw-rw- 1 root root 248, 0 Jul 13 01:45 /dev/nvidia-uvm
>
> A quick test program, as well as possible fixes, are in the Reference
> below. The question now is, how best to handle this in the slackbuild?
>
> 1. put this in doinst.sh
>      mknod -m 660 /dev/nvidia-uvm c 249 0
>      chgrp video /dev/nvidia-uvm
>
> 2. udev rule?
>      KERNEL=="nvidia_uvm", RUN+="/usr/bin/bash -c '/usr/bin/mknod -m 666
> /dev/nvidia-uvm c $(grep nvidia-uvm /proc/devices | cut -d \ -f 1) 0;
> /usr/bin/chgrp video /dev/nvidia-uvm'"
>
> 3. Compile nvidia-modprobe by default (optional now) so that X userland
> can make the node, or invoke via doinst.sh if not.
>
> I'll post this in LQ as well to get better coverage.
>
> References:
> 1.
> https://devtalk.nvidia.com/default/topic/699610/334-21-driver-returns-999-on-cuinit-cuda-/
> 2.
> http://us.download.nvidia.com/XFree86/Linux-x86/340.24/README/faq.html

Thanks for the heads-up. I need CUDA/OpenCL support right now. Using the 
.run-file will give me the nvidia-uvm device.

Regards,
Mats