GPU hang trying to run OpenCL kernels on x86_64

[Luís Mendes]

Hi,

I am a collaborator with Syncleus/aparapi project on github and I've
been testing OpenCL on AMD and NVIDIA cards.

Currently I have a set of kernels that hang the GPU (AMD RX 460 and
AMD RX 550) across all compute units on x86_64 running vanilla kernel
4.16.7 on Ubuntu 18.04, also on Ubuntu 16.04.4 with AMDGPU PRO 17.50
and 18.10 show the same problems, in fact, AMDGPU-PRO 18.10 is even
worse.

However the same set of kernels run happily on armhf with vanilla
Linux 4.16.7 and mesa 18.0 (mesa-opencl-icd and libclc for amdgcn),
Ubuntu 17.10, on an AMD RX460 and an AMD RX 550.

Luís Mendes