[Libre-soc-dev] gpus and fences

[Jacob Lifshay]

This thread on dri-devel is relevant for Kazan, having to do with what kind
of synchronization primitives the linux gpu ecosystem should use:
https://lists.freedesktop.org/archives/dri-devel/2021-April/303865.html

Kazan runs into issues due to being in user-space and the standard linux
gpu sync primitive being a dma-fence which is required to have kernel-level
finite completion time guarantees. user-space can't directly provide
something like that since someone could send sigstop or something to the
user process, causing a kernel-level deadlock.

Jacob