Thanks jggimi! My swap is twice as big as my RAM, so I should be good there. I'll try typing 'boot crash' and waiting 10 minutes next time I get a proper hang.
That said, last night when I was turning off various services in an attempt to see if one of them was the culprit, I tried running plain startx with the default desktop, no gnome, then I played a video for 20m or so using Totem. Screen froze as before, but the audio from the video
kept going through what I believe was the end of the video. Pressing keys on the keyboard and mousing didn't do anything, at least, that I could see.
So...perhaps I have a video issue and not a hang. I'm going to try this again in Gnome, get the video to play in a loop, see if it hangs or just
looks like its hung, try and SSH into the box if the video keeps playing. Maybe there's a way I can reboot the video driver while SSHed in, that would be something.
Also, a couple lines in the -current release notes caught my eye:
- "Made intel(4) clflush() flush the correct cache line on i386/amd64. Fixes gnome screen corruption and hangs."
- "Bugfixes to drm(4) i915 code to avoid possible Haswell system hangs and GPU locks."
This is not a Haswell laptop, but perhaps the issue I'm encountering is fixed in -current. Seems I'm going to have to bite the bullet and install -current.