What CS skills are needed to do research in Operating Systems?

Pure math guy here. Interested in applied CS. What skills are needed to do research in computer systems / operating systems area at the PhD level?

OS design is the epitome of autism.

How come?

Queuing theory maybe

electrical/computer engineering type stuff

you'll need to understand circuits, digital logic design techniques, computer architecture

computational theory, compiler constuction, etc. will also be useful

excellent- thanks! any recommended textbooks/resources/moocs?

There's a sticky with excellent book tips

great thanks

There's nothing to be gained from studying OSes at the PhD level. Get hired to Google's OS team and work on the Fuschia OS or the Magenta kernel

I'm not that guy but it's extremely detailed work.

An OS needs a kernel, which is essentially a program that runs other programs. In order to pull this off the kernel needs to solve all sorts of scheduling problems simultaneously in a clever way. You want several processes to be able to share processor time, you want IO and memory to be accessed efficiently (they're way slower than CPU caches), you want processes to be able to share memory, you want processes to be forkable, you want to be able to handle multiple CPUs/cores at the same time, etc...

There are no perfect solutions to any of those scheduling problems so you've just got a whole bunch of similar algorithms with different tradeoffs that you've got to familiarize yourself with.

That's still just introductory OS stuff (not even an entire semester of an intro undergrad course on the subject).