Interrupts

Operating Systems Demystified: From Processes to Scheduling An operating system (OS) sits between software and hardware. It shares the computer’s time, memory, and devices with many programs. A good OS keeps things fair, fast, and safe for users around the world. At the core are processes and threads. A process is a running program with its own memory and resources. A thread is a lightweight path of execution inside a process. Many apps use several threads so the interface stays responsive even while a task runs in the background. ...

A Practical Intro to Operating Systems Internals Understanding what an operating system does inside a computer helps you write better software and design reliable systems. An OS creates a friendly space for your programs to run, protects each program from others, and manages resources like CPU time, memory, and I/O devices. It coordinates many tiny steps behind the scenes so apps feel fast and safe. A modern OS runs in two kinds of code: user mode and kernel mode. User programs run in user mode, while the kernel runs in a privileged mode. When a program needs a service, it performs a system call, the kernel checks permissions, performs the task, and returns control. This boundary keeps faults from crashing the whole system. ...

Operating System Internals for Systems Programmers Operating systems hide many moving parts behind a simple interface. For systems programmers, knowing what lives inside the kernel helps you write faster, safer software and diagnose problems more quickly. This article gives a clear map of the main areas: memory, processes, I/O, and system calls. By grounding your work in these ideas, you can spot bottlenecks and design better interactions with the OS. ...

Operating Systems: Kernel Design and Scheduling Demystified Understanding how an operating system works starts with the kernel. The kernel is the core software that manages CPU time, memory, devices, and security. It sits between applications and hardware, enforcing rules and coordinating many tasks at once. For learners, this helps explain why some programs feel snappy while others wait for resources. Kernel design choices Kernel design choices shape speed and safety. A monolithic kernel puts most services in one big block, which can be fast but harder to update. A microkernel keeps only essential parts in kernel mode and runs other services in user space, trading some speed for better isolation. Modern systems mix ideas with modules to balance performance and reliability. ...