tumblerd grabs the wrong GPU and offloads work to it

When using Thunar, tumblerd starts itself up and grabs both of the GPUs in my system to offload work, including a machine learning card that doesn't have automatic fan control, using up RAM and ramping up its temperature, sometimes to the thermal limit. Even when not actively using Thunar tumblerd will start itself and do something in the background, then kill itself and repeat. This doesn't seem to stop even when all thumbnails have been generated

Steps to reproduce:

• Have a multi-GPU system. In my case, a GTX 1080Ti with a Tesla M40
• Monitor GPU performance with nvidia-smi or similar
• Have Thunar open in a directory where thumbnails need to be generated (or possibly any directory, it's not clear why it's running, and in some cases it runs for hours)

Observed behavior:

• /usr/lib/x86_64-linux-gnu/tumbler-1/tumblerd starts itself
• GPU utilization increases

Expected behavior:

• tumbelrd doesn't use the GPU and/or uses the GPU that has a display attached, and/or it's a configurable option