Under memory pressure, graphics load may freeze the system

[Leonardo Müller]

When the system is under memory pressure (400 MB available from 8 GB and 600 MB swap usage), certain graphics workloads can freeze the system. Apparently, the system continues working, as sounds play normally. However, most programs seem to freeze, the screen no longer updates, nor the mouse moves, nor the keyboard lights from Num Lock, Caps Lock and Scroll Lock work.

In the last crash I was playing Elite Dangerous using Steam Play with DXVK and was in a Discord call in Opera Developer. When the system froze, I was still able to talk and hear in the call and pressing Alt+PrintScreen+S allowed the disk to sync, as the hard disk could be heard and the syslog was saved.

The pattern to have this is to be under memory pressure and have a heavy graphics workload.

If the conditions are met, then this may happen. This is a rare event, but it seems to be impossible to recover when it happens as it seems to be impossible to remove the i915 module, even using the force options. Forcibly powering off by holding the power button is the only option.

Distribution: Xubuntu 18.04.2 amd64;
Kernel version: 4.18.0-20-lowlatency;
Processor: Intel Core i3-6100U;
Video: Intel HD Graphics 520;
RAM: 8 GB.

ProblemType: Bug
DistroRelease: Ubuntu 18.04
Package: linux-image-4.18.0-20-lowlatency 4.18.0-20.21~18.04.1
ProcVersionSignature: Ubuntu 4.18.0-20.21~18.04.1-lowlatency 4.18.20
Uname: Linux 4.18.0-20-lowlatency x86_64
ApportVersion: 2.20.9-0ubuntu7.6
Architecture: amd64
CurrentDesktop: XFCE
Date: Fri May 24 22:49:15 2019
InstallationDate: Installed on 2017-06-13 (710 days ago)
InstallationMedia: Xubuntu 17.04 "Zesty Zapus" - Release amd64 (20170412)
SourcePackage: linux-signed-hwe
UpgradeStatus: Upgraded to bionic on 2017-10-20 (582 days ago)