Cannot access secondary GPU - error: Could not load GPU driver

[so-rose]

The error above happens when I try to optirun something, glxgears or otherwise. I work with Blender 3D, making not being able to access my GPU extremely frustrating.

When I run optirun -vvv glxgears, I get this (just the important bit):

...
[  860.372651] [DEBUG] Primus LD Path: /usr/lib/x86_64-linux-gnu/primus:/usr/lib/i386-linux-gnu/primus:/usr/lib/primus:/usr/lib32/primus
[  860.372718] [DEBUG]Using auto-detected bridge primus
[  860.375964] [INFO]Response: No - error: Could not load GPU driver

[  860.376023] [ERROR]Cannot access secondary GPU - error: Could not load GPU driver

[  860.376056] [DEBUG]Socket closed.
...

My bumblebee.conf has Driver=nvidia and KernelDriver=nvidia-current (which I determined by running find /lib/modules/$(uname -r) -name 'nvidia*.ko*' as per the troubleshooting instructions in the wiki).

Here are my system specs:

uname -a output: Linux iceraven 3.14-2-amd64 #1 SMP Debian 3.14.15-2 (2014-08-09) x86_64 GNU/Linux
GPU: Nvidia 780M
Driver: Components of the nvidia-driver metapackage (recently updated to nvidia driver version 340.something) in the jessie repo.

Thank you in advance!

[ryanvade]

What are the LibraryPath and XorgModulePath set to in bumblebee.conf ? Can you manually load nvidia-current with modprobe?

[so-rose]

Thanks for the quick reply!

Before I go further, I'll assert that the nvidia driver and bumblebee are installed via dkms. Here are the stats from my bumblebee.conf:

LibraryPath=/usr/lib/x86_64-linux-gnu/nvidia:/usr/lib/i386-linux-gnu/nvidia:/usr/lib/nvidia
XorgModulePath=/usr/lib/nvidia,/usr/lib/xorg/modules

I was able to load nvidia-current using modprobe nvidia-current nvidia-uvm, so that the output of lsmod | grep nvidia included nvidia and nvidia-uvm (more on this one later). At that point, optirun glxgears worked.

That, however, is when I remembered a certain issue I've had for many months, where Blender would be unable to use CUDA, stating that it was unable to load nvidia-uvm - the very same module that was next to nvidia-current in the output of find /lib/modules/$(uname -r) -name 'nvidia*.ko* - the full path to the referenced directory, on my machine, is /lib/modules/3.14-2-amd64/updates/dkms

When I finally found a way to brute force nvidia-uvm to load (modprobe was not working), I could not turn off the GPU any more with echo OFF > /proc/acpi/bbswitch. Sure enough, that function was blocked as soon as I executed modprobe nvidia-current nvidia-uvm - only after I ran modprobe in opposite order and with -r was I able to turn off the gpu with echo OFF > /proc/acpi/bbswitch.

Bumblebee should have been able to find the modules in /lib/modules/3.14-2-amd64/updates/dkms - this smells like a bug. In lieu of that, is there a setting I can alter to make bumblebee look for the modules there?

[Lekensteyn]

Does modinfo nvidia-current and modinfo nvidia-uvm list the modules? If not, try to run sudo depmod -a (which should already have been done by DKMS).

For issues around unloading nvidia-uvm, see 1ada79f

[so-rose]

Sorry for the late reply.
I tried the commands; they do seem to list the modules correctly:

modinfo nvidia-current

filename:       /lib/modules/3.14-2-amd64/updates/dkms/nvidia-current.ko
alias:          char-major-195-*
version:        340.24
supported:      external
license:        NVIDIA
alias:          pci:v000010DEd00000E00sv*sd*bc04sc80i00*
alias:          pci:v000010DEd00000AA3sv*sd*bc0Bsc40i00*
alias:          pci:v000010DEd*sv*sd*bc03sc02i00*
alias:          pci:v000010DEd*sv*sd*bc03sc00i00*
depends:        i2c-core
vermagic:       3.14-2-amd64 SMP mod_unload modversions 
parm:           NVreg_Mobile:int
parm:           NVreg_ResmanDebugLevel:int
parm:           NVreg_RmLogonRC:int
parm:           NVreg_ModifyDeviceFiles:int
parm:           NVreg_DeviceFileUID:int
parm:           NVreg_DeviceFileGID:int
parm:           NVreg_DeviceFileMode:int
parm:           NVreg_RemapLimit:int
parm:           NVreg_UpdateMemoryTypes:int
parm:           NVreg_InitializeSystemMemoryAllocations:int
parm:           NVreg_RMEdgeIntrCheck:int
parm:           NVreg_UsePageAttributeTable:int
parm:           NVreg_MapRegistersEarly:int
parm:           NVreg_RegisterForACPIEvents:int
parm:           NVreg_CheckPCIConfigSpace:int
parm:           NVreg_EnablePCIeGen3:int
parm:           NVreg_EnableMSI:int
parm:           NVreg_MemoryPoolSize:int
parm:           NVreg_RegistryDwords:charp
parm:           NVreg_RmMsg:charp
parm:           NVreg_AssignGpus:charp

modinfo nvidia-uvm

filename:       /lib/modules/3.14-2-amd64/updates/dkms/nvidia-uvm.ko
supported:      external
license:        MIT
depends:        nvidia
vermagic:       3.14-2-amd64 SMP mod_unload modversions

Just to be certain, I ran sudo depmod -a anyway. To be clear, I have had no trouble loading or unloading nvidia_uvm or nvidia-current - bumblebee simply does not seem to do it automatically when starting a program under optirun or quitting a program running under optirun.

[ArchangeGabriel]

As per #623, the problem might be that nvidia need nvidia-uvm but is unable to load it. Need to look at this.

[aurelienpierre]

I absolutely needed OpenCL to work with Darktable so I created a quick fix :

1. create a script called for example opencl-program.sh like this :

#/bin/sh
gksudo modprobe nvidia_352_uvm && # Because I run nvidia-352 but replace with your correct driver version and module

darktable

exit

1. then create a menu launcher were you call the script with the command :

optirun sh opencl-program.sh

It's not optimal but it works. Notice you have to load nvidia_***_uvm through optirun command and in the same console than your program call to make it work. Be careful to be sure that the script ended properly and the "exit" command was reached to close the Bumblebee process after your program, or kill it the hard way if something went wrong in your script. Otherwise, if you load another program with optirun, your system will crash.

As soon as the script is finished or the console closed, the uvm module is unloaded so you will have to redo the modprobe command if you whish to load another program with the GPU. You can check the loaded modules with :

optirun lsmod

Notice that the latest Nvidia drivers seem to name the uvm module with underscore _ instead of dash -. You can check your actual modules names with the command :

ls /lib/modules/$(uname -r)/updates/dkms/

[ArchangeGabriel]

Well this means will also need to take care of loading nvidia_uvm (and possible nvidia_modeset) if they don’t on they own.