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.
The kernel, running in kernel mode, has no handcuffs. It can do anything. what is os kernel
The kernel is the . Everything else runs in a sandboxed theater. The Three Sacred Duties Beneath the abstraction, the kernel performs three interlocking duties that resemble the functions of a biological brain. The kernel’s most radical act is the invention
The kernel is not really software. It is a . This is a hallucination, induced by the kernel’s scheduler
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.
The CPU does not know what a “file” is. It does not know what a “network socket” is. It does not know that you have a right to privacy, that two programs shouldn’t write to the same memory location, or that time should be shared fairly among a hundred running tasks. The CPU is a breathtakingly fast idiot, capable only of fetching an instruction, decoding it, executing it, and moving to the next address.