Linux kernel is massive and has been around for decades now and it’s probably millions of lines.
It certainly has a lot of cognitive overhead since you need to always keep in mind the context in which the code you are writing will be running (to reason about concurrency etc.), but it’s relatively easy to understand and well written.
It certainly has a lot of cognitive overhead since you need to always keep in mind the context in which the code you are writing will be running (to reason about concurrency etc.), but it’s relatively easy to understand and well written.