In Magento admin it's showing 2.2.1 in the lower right, not sure where else to look if there's more revision information somewhere else. I updated to that version through the Magento Admin - Web Setup Wizard about a week ago, and I just checked again and it says I'm at the latest version.
I did manage to find this github issue that accurately described my issue and provided a work around - https://github.com/magento/magento2/issues/11002
The issue for me was that the .cron_schedule table grew to 208,000 rows in a few weeks, and my site is just in development. After running
delete from cron_schedule where scheduled_at < date_sub(now(), interval 1 hour);
the cron_schedule table went down to only 250 rows and then immediately all 3 cron jobs in 5 seconds or less. I added that query to my crontab to run every 15 minutes and it's been going since sunday, all 3 magento crons are still running pretty much instantly. The cron_schedule table is now keeping steady at about 1030 - 1060 rows, with the MySQL delete query deleting about 20 rows every 15 minutes.