The Linux kernel comprises the heart and soul of the Linux OS. It is also one of the world’s largest open-source project with about 13 million-plus lines of code. In this article, we go over the Linux kernel. What does it do? Where does it stand in the hierarchy? And everything else important.
The Linux kernel is essentially what a kernel is — an interface between the computer hardware and the processes associated with it. As you would have guessed, it forms the core component of the Linux OS.
It stays inside the OS and controls all primary functions associated with the device’s hardware, be it a smartphone, laptop, server or any other kind of processing machine. The kernel is responsible for communicating all the ‘user’ level commands (or applications) to the hardware as well as allowing processes to get information using each other.
In terms of architecture, the Linux kernel is monolithic. This means that it not only covers core areas like the CPU and memory but a lot of extras like device drivers, file system management, and so on. This monolithic architecture, alongwith kernel modules, is responsible for the fantastic out-of-the-box support offered by Linux.
Kernel modules are something nine reasons why developers tend to choose Linux over Windows originally came up with to counter the challenges face by the monolithic architecture. A kernel module adds functionality and support to the base kernel for things like devices, system calls, file systems, and so on. They are essential to keeping the kernel functioning.
What does the kernel do?
Aforementioned, the kernel is responsible for the interaction of user applications with computer hardware. However, due to its monolithic nature, the Linux kernel does a little bit more than that.
It takes care of four primary things:
- Memory Management: It keeps track of the amount of memory used to store what and where.
- Process Management: This, of course, the core functionality of the kernel — determining what process can use the CPU when, how much and for how long.
- System Calls: Another core function of the kernel, this involves receiving a request for service from various processes.
- Device Drivers: It acts as an interpreter between various hardware devices and their corresponding processes.
Where does the kernel stand?
Consider this; your Linux machine is made up of three layers. The first layer is, of course, your hardware. This includes everything that the machine has physically. RAM, I/O devices, CPU and everything else.
Second, comes the Linux kernel. This is the core of the operating system residing right in the middle. This piece of code lives in the CPU and runs the show.
The third is the user processes. These are the programs that you run on your system and are managed by the kernel. These processes collectively make up the user space and are known as user process regardless of whether the user interacts with them or not. The kernel also facilitates these processes to communicate with each other.
If appropriately implemented the kernel works in its little world called the kernel space and is completely hidden from the user. It isn’t magic, but it forms the backbone of any OS and is essential to your computer’s functioning.
Also read: Linux Gaming: Viable or not?