Going through the Linux source code is like picking the technical nuances of Linux first hand. Without an iota of doubt Linux within it has all the concepts and skills that a system programmer needs, I figured this out the hard way. Programming excellence can be achieved through ripping the source apart and diagnosing it. Let me list you some direct benefits ushered by source code reading
First hand information
You can read from books, get information from the Internet or by other means but nothing like knowing it first hand by exploring the Linux source code. This rich treasure of GNU / C code has got everything that you are looking for. This information leaves absolutely no space for any doubts as this is the final original source of information and there are zero alternates to this. As you comprehend these pieces of code it's like going through the minds of the people who have actually written it. And this experience and the kind of learning involved will never be found anywhere.
Improve your conceptual clarity
As you follow the flow of the code, the concepts get unfolded and the maze starts to show you the way. Personally I go through this process whenever I'm tied in two minds on a particular OS concept. It cuts down the need for looking for other sources; however this needs some real experience. If you do this exercise regularly then I'm sure cracking or understanding any technical concept, even though it is not related to an OS becomes a piece of cake for you
Efficient code writing style and skill
Just look and appreciate the style and standards followed by this open source marvel that has stood the time and taken the brunt of real time performance and emerged as the best open project ever. The coding standards are so defined and stable that all these varied pieces of code contributions from all over the world has never bought this thing down. So one thing that you undoughtly get is the skill to code like a top class pro.
Rock solid confidence
This requires serious mention, when I first started off with the initial versions of the Linux kernel the best thing that I got was a truck load of confidence. This single benefit was the sole reason for all my success as a programmer and as a trainer. Lack of confidence can even hinder the growth of a technically sound individual. So get that confidence right now with some useful source code reading
Increased adaptability to change
If you achieve the design and frameworks on which these operating systems are build and if you go back to the previous versions of Linux and track down the progress you will no doubt heighten your clarity and grip on the subject. You will also become most adaptable to future changes and you can even predict technological changes, which may often become real. So this skill will equip you with the flexibility and adaptability to changes
I for sure know that this is a small list of benefits that source code browsing can bring to you. If you have done this before then I request you to add to this list of benefit through your valuable feedback