[elrepo] Problem with CUDA since 331.67.elrepo

[Akemi Yagi]

On Thu, Apr 24, 2014 at 4:31 PM, Michael Lampe <mlampe0 at googlemail.com> wrote:
> They now have a second kernel module 'nvidia-uvm' that wants to be built and
> packaged too. Affected are both older CUDA versions and the new 6.0.
>
> While that's easy to fix, there is an annoying little problem. There comes a
> new device file '/dev/nvidia-uvm' with the new driver module. And it picks
> an arbitrary unused major no. at load time. So you cannot have it loaded by
> modprobe automatically when the device node is accessed, because you cannot
> create the device node before the module is loaded, and you also cannot use
> udev in any way because this module creates no data in sysfs and therfore
> creates no udev events.
>
> But the usage pattern is that CUDA programs will access '/dev/nvidia-uvm'
> and expect everything to be already in place.
>
> The only solution I found is to piggyback the new module + device creation
> on the old one:
>
> $ cat /etc/modprobe.d/nvidia
> options nvidia NVreg_ModifyDeviceFiles=0
> install nvidia /sbin/modprobe --ignore-install nvidia; /sbin/modprobe
> nvidia-uvm; /bin/mknod -m 0600 /dev/nvidia-uvm c `/bin/grep nvidia-uvm
> /proc/devices | /usr/bin/cut -d' ' -f1` 0; /sbin/pam_console_apply
> /dev/nvidia-uvm
>
> This works because '/proc/devices' reveals what major the new module picked.
> Permissions are set and (automatically) maintained with the same logic that
> applies to the other /dev/nvidia* files.
>
> What do you think? If nobody comes up with a better idea, I'll post the
> complete patch.
>
> -Michael

Thanks for this post. There is a bug entry for this issue at:

http://elrepo.org/bugs/view.php?id=471

Could you join in there and upload your patch?

Akemi