[cyphar]

In my view, "reading the kernel" is not really a useful exercise. Source code isn't a book, and most code isn't really a pleasure to read by itself.

Instead I would suggest that you try to debug a problem, or try to understand what a particular syscall does rather that starting from init/main.c. If you have a goal in mind (trying to solve a problem or understand a specific aspect of the kernel) you are far more likely to get useful information out of the exercise.

Another useful hint is that you should just ignore the majority of code that looks alien. Linux uses a lot of macros and synchronisation primitives that you probably aren't familiar with (RCU for instance). It's much more useful to take note of the things you don't understand and just move on to the code code that you do understand. Most of the macros and synchronisation primitives are used all over the kernel so you're very likely to get to grips with them over time.

I really hope that bpftrace will make it easier for people to get into kernel debugging and thus have a nicer "in" to kernel development.