Okay, are we alive?

If we stay alive, it is because the shit I guessed was correct. Got I/O errors attempting to use memory hotplug. The memory failure subsystem (/usr/src/linux-*/Documentation/ABI/testing/sysfs-memory-page-offline) worked, but I'm not entirely certain I got the addresses right; often, mcelog and dmesg and /sys have different opinions on what an address is. But no MCEs, no problems, everything seems fine, and the VM hasn't had an aneurysm yet, so I guess it's cool.

I look forward to forgetting what I typed that fixed it by the next time something retarded happens and the machine reboots.