Comment 4 for bug 1710941

Thanks Daniel. Rolling back to kernel 4.4.0-87-generic #110-Ubuntu SMP seemed to fix the problem. Upgrading to 4.4.0-91 also seemed to cause other problems: My system started overheating, eventually slowed to a crawl (i.e., over a matter of minutes after each reboot slowed to the point of being unresponsive), and I saw 4 instances (one for each core, I presume) of kidle_interrupt, which I had never seen before.

I notice that 4.4.0-91 is no longer showing up as an update in the repos for 16.04.

For what it's worth, I also downgraded libgd3 to version 2.1.1-4build2, as it also upgraded around the same time as my recent kernel updates (-87 and -89, but I don't think I ever rebooted into -89).