Intel Opencl freezes system

[Jan W]

I have an Intel i5 (Skylake) based laptop. (With a Geforce 940m that I'm not using for the purpose of this bug report). I installed intel-opencl-icd to make use of the Intel NEO opencl driver in Darktable.

When I use Darktable in combination with the Intel NEO driver for a few minutes, the complete system freezes. The screen remains on, but the system does not react to either CTRL-ALT-DEL, CTRL-backspace or CTRL-ALT-SYSREQ-BUSIER.

The freeze does not occur when the intel-opencl-icd package is not installed.

I viewed dmesg and temperature sensors in parallel with the usage of darktable. No messages from dmesg, temperatures of the CPU are between 50-55 degrees, which seems no issue. I also don't suspect power usage, as I can use the Nvidia GPU while gaming without problems (CPU also gets much hotter then).

I tried a newer version from https://github.com/intel/compute-runtime/, but it shows the same problem.

Kernel version is 5.0.0-20-generic

ProblemType: Bug
DistroRelease: Ubuntu 19.04
Package: intel-opencl-icd 19.13.12717-0ubuntu1
ProcVersionSignature: Ubuntu 5.0.0-20.21-generic 5.0.8
Uname: Linux 5.0.0-20-generic x86_64
NonfreeKernelModules: zfs zunicode zavl icp zcommon znvpair
ApportVersion: 2.20.10-0ubuntu27.1
Architecture: amd64
CurrentDesktop: KDE
Date: Sun Jul 21 22:19:13 2019
InstallationDate: Installed on 2016-02-03 (1264 days ago)
InstallationMedia: Error: [Errno 13] Permission denied: '/var/log/installer/media-info'
SourcePackage: intel-compute-runtime
UpgradeStatus: Upgraded to disco on 2019-05-13 (69 days ago)