When you call open() , read() , write() , fork() , you are not performing an action. You are making a to the sovereign circuit. And the kernel, if it is in a good mood, will grant it.
Every few milliseconds, a hardware timer interrupts the CPU. The kernel seizes control, pauses the current process, saves its registers, looks at its list of ready processes, picks the next one, and restores its state. This is called a context switch, and it happens thousands of times per second. The kernel is a time lord, chopping the continuous flow of the clock into discrete slices and distributing them with ruthless fairness (or deliberate priority). what is os kernel
Hardware is asynchronous. The disk finishes reading. The network card receives a packet. The keyboard is pressed. The kernel must respond to these events in microseconds. When you call open() , read() , write()
To truly understand the kernel, you must abandon the perspective of the user or even the application developer. Instead, you must adopt the perspective of the . Every few milliseconds, a hardware timer interrupts the CPU
Thus, the kernel is the machine’s subconscious. You never see it. You never talk to it directly. But every moment of order, every byte of data, every flicker of your screen is a testament to its silent, absolute, and deeply beautiful tyranny.
The kernel’s most radical act is the invention of concurrency . On a machine with a single core, only one instruction can run at a time. Yet you can listen to music, type a document, and download a file simultaneously. This is a hallucination, induced by the kernel’s scheduler.