The oldest x86 processor still supported by a modern Linux kernel?

What is the oldest x86 processor that is still supported by a modern Linux kernel in present time?I asked the above quiz question during the Geekcamp tech conference in Nov 2017 during my emcee role. The theoretical answer as you can glean from the title of this post is the 486 which was first released in 1989. I determined that fact from this article where support for the 386 was dropped in Dec 2012.To get you interested, here is the result of my effort.Cool project.