While doing normal text editor / web browser / Discord / Steam work, the hard drive light suddenly turned on and wouldn't ever turn off. The keyboard and mouse immediately became unresponsive, and not even ctrl-alt-f3 would work.
Glancing at logs after a hard reset, it appears unsurprisingly to be due to running out of memory.
Is there a way to adjust the oom killer to have a larger margin? If it kicked in at all here, it appears to have been way too late to avoid a hard reset.