OptiX 6.0.0 denoiser generating SIGBUS

Gaming and Visualization Technologies Visualization OptiX
1

Hello,

I work on a renderer based on OptiX 6.0.0 (with cuda 10.2) and using OpenGL for some rasterization. The renderer uses Optix 6.0.0 denoiser for the output image. Everything seems to be working fine.
The renderer is running on Linux Ubuntu 18.04 on a google cloud VM using 4 Tesla T4 with drivers 440.100. The program on this setup is working, but when building it on a separate computer using a GTX 970 and copying the executable on the VM, it fails by generating a SIGBUS randomly when calling the function rtPostProcessingStageCreateBuiltin(…) for the denoiser (the renderer is running on only one of the four gpus available after the call to rtContextSetDevices).

So I was wondering if this could be due to the fact that we are building the renderer with a non-RTX graphic card ?
Plus even when using dll from optix 6.0.0, the reported version by rtGetVersion is 6.6.0, is that normal ?

2

Hi when you say it fails randomly, does that mean it doesn’t always fail?

And when you are copying the executable to the VM, does this include precompiled PTX?

–
David.

3

That’s right, sometimes, it succeed and the program runs fine, sometimes, it fails with a sigbus.

Yes, we are also copying the precompiled PTX from the build machine to the VM for execution. We cannot build for cuda compute capability 7.5 so we build for cc 5.2 as the build machine has a GTX 970, could that be a problem ?