Document how to use NVIDIA GPUs

[nikolaszimmermann]

We have a bunch of support code to assist in supporting NVIDIA GPUs using the proprietary driver - but yet to be documented.
Currently nvidia-smi / NVIDIA Nsight Sytems / .. works fine in wkdev-sdk, cog+MiniBrowser with old WPE API, but not yet with the new one due to GBM-in-container issues (nvidia-drm_gbm.so is not existant - upstream issue).

[fujii]

I installed the latest nvidia-container-toolkit-base, but still an error occured:

📦 fujii@wkdev:~/g/$ ./Tools/Scripts/run-minibrowser --debug --wpe                                                                    [main] [23:47:30]
Using default MiniBrowser
ERROR: Failed to make thread real time: GDBus.Error:org.freedesktop.DBus.Error.Failed: No such file or directory
/home/fujii/g/Source/WTF/wtf/linux/RealTimeThreads.cpp(224) : void WTF::RealTimeThreads::realTimeKitMakeThreadRealTime(uint64_t, uint64_t, uint32_t)
ERROR: Failed to make thread real time: Timeout was reached
/home/fujii/g/Source/WTF/wtf/linux/RealTimeThreads.cpp(224) : void WTF::RealTimeThreads::realTimeKitMakeThreadRealTime(uint64_t, uint64_t, uint32_t)
ERROR: Failed to make thread real time: Timeout was reached
/home/fujii/g/Source/WTF/wtf/linux/RealTimeThreads.cpp(224) : void WTF::RealTimeThreads::realTimeKitMakeThreadRealTime(uint64_t, uint64_t, uint32_t)
KMS: DRM_IOCTL_MODE_CREATE_DUMB failed: Permission denied
KMS: DRM_IOCTL_MODE_CREATE_DUMB failed: Permission denied
Failed to create GBM buffer of size 2048x1536: Permission denied
ERROR: WebKit encountered an internal error. This is a WebKit bug.
/home/fujii/g/Source/WebKit/WebProcess/Network/WebLoaderStrategy.cpp(618) : void WebKit::WebLoaderStrategy::internallyFailedLoadTimerFired()

Adding export GBM_BACKENDS_PATH=/usr/lib64/gbm to my ~/wkdev-home/.zprofile works around.

[nikolaszimmermann]

Interessting, thanks @fujii. @bertogg - this reminds me of the EGL problems from your debian ticket... - maybe GBM doesn't work with nvidia, because the right backend can't be found.

[bertogg]

It doesn't seem to make a difference, the user reports this error:

LANG=C && GBM_BACKENDS_PATH=/usr/lib/x86_64-linux-gnu/nvidia/current GBM_BACKEND=nvidia-drm liferea
<sys>:0: Warning: g_atomic_ref_count_dec: assertion 'old_value > 0' failed
KMS: DRM_IOCTL_MODE_CREATE_DUMB failed: Permission denied
KMS: DRM_IOCTL_MODE_CREATE_DUMB failed: Permission denied
Failed to create GBM buffer of size 469x199: Permission denied

[fujii]

I have one more problem with the proprietary nvidia driver. All layout tests are timing out if I run some WebKitTestRunner processes parallely. Adding --child-processes=4 switch works around the problem. I switched back to the open source nouveau driver. It has no problem.