Anatomy of the Linux Kernel

LinucksGirl writes "The Linux kernel is the core of a large and complex operating system, and while it's huge, it is well organized in terms of subsystems and layers. In this article, the reader explores the general structure of the Linux kernel and gets to know its major subsystems and core interfaces. 'When discussing architecture of a large and complex system, you can view the system from many perspectives. One goal of an architectural decomposition is to provide a way to better understand the source, and that's what we'll do here. The Linux kernel implements a number of important architectural attributes. At a high level, and at lower levels, the kernel is layered into a number of distinct subsystems. Linux can also be considered monolithic because it lumps all of the basic services into the kernel. This differs from a microkernel architecture where the kernel provides basic services such as communication, I/O, and memory and process management, and more specific services are plugged in to the microkernel layer.'"

Comments

Protected from Commercial Exploitation?

[smartbei]

From TFA (emphasis mine): "Linux quickly evolved from a single-person project to a world-wide development project involving thousands of developers. One of the most important decisions for Linux was its adoption of the GNU General Public License (GPL). Under the GPL, the Linux kernel was protected from commercial exploitation, and it also benefited from the user-space development of the GNU project (of Richard Stallman, whose source dwarfs that of the Linux kernel). This allowed useful applications such as the GNU Compiler Collection (GCC) and various shell support." Tivo?

okay but one major error

[belmolis]

The diagrams are nice and for the most part the text is okay, but there is one glaring error that should have been edited out before this was published:

There is also the GNU C Library (glibc). This provides the system call interface that connects to the kernel and provides the mechanism to transition between the user-space application and the kernel.

This is false and could be very confusing for readers who don't already know about the structure of Linux. The diagram gets it right.

Intriguing

[peterjb31]

Interesting article but really quite vague.

Re:Good article...

[Per Wigren]

RTFA. Linux From Scratch is not about understanding the insides of the kernel, it's all about building a custom distro.

Re:A Brief History of Kernel Size

[Daniel Dvorkin]

Over that same period, the RAM, processor cycles, and HD space sitting on my desk all increased by a factor of about 2000. So I'd say a five-fold increase in kernel size isn't too bad -- and a hell of a lot better than most software has done.