Operating-Systems

Operating System Internals Kernel Scheduling and Memory Modern operating systems separate two core jobs: deciding which task runs on the CPU, and organizing memory so programs can run safely and fast. Scheduling and memory management work together to make a computer responsive. How the kernel schedules work The scheduler keeps a list of tasks that are ready to run. Each task has a priority or weight, and the CPU gets a slice of time, called a timeslice. When a timeslice ends, the scheduler re-evaluates who should run next. On systems with multiple cores, several tasks can run at once, but the same rules apply to all cores. ...

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. ...

The Fundamentals of Operating Systems Scheduling Scheduling decides which process runs next on the CPU and for how long. A good scheduler keeps the system responsive, makes efficient use of hardware, and treats tasks fairly. It works with the ready queue, where waiting processes line up, and with the running state, when a task is actually executing. When a process waits for I/O, the scheduler hands the CPU to another candidate. ...

A Practical Guide to Operating Systems An operating system (OS) is the software layer that helps apps talk to hardware. It manages CPU time, memory, storage, and I/O devices so programs run smoothly. For most users, the OS stays in the background, turning clicks and keystrokes into actions and keeping the system stable. Two core parts shape every OS: the kernel and user space. The kernel runs in high privilege. It handles processes, memory, files, and devices. User space holds everyday programs. The OS schedules tasks, allocates memory, and keeps programs isolated to prevent one crash from affecting others. ...

A Practical Guide to Operating Systems Fundamentals An operating system (OS) is the software that manages a computer’s resources and provides services for programs. It keeps the hardware busy and safe, so apps run smoothly. A good OS protects memory, schedules work, stores files, and talks to devices like keyboards and disks. Differences exist between Windows, macOS, Linux, or mobile systems, but the core ideas stay the same. Core roles of an OS Manage CPU time so many programs can run without stepping on each other. Control memory, so one app does not crash another. Handle files and devices, from reading a file to printing a page. Processes and memory management A program runs as a process. Each has its own memory space, state, and resources. The OS uses virtual memory to give each process the feeling of a private memory, even if the physical RAM is shared. The memory manager maps virtual pages to physical frames, and it can swap pages to disk when needed. This keeps programs isolated and responsive. ...

Understanding Operating Systems: A Practical Introduction An operating system, or OS, is the software that coordinates a computer’s hardware and runs applications. It provides a stable place for programs to run and keeps devices working together. In short, an OS is the manager of memory, time, and access to the disk. Core components Kernel: the central piece. It runs with high privileges and handles memory, processes, devices, and system calls. ...

Operating Systems Demystified: From Kernels to User Space An operating system (OS) is the software that helps a computer run smoothly. It coordinates hardware, runs programs, and makes devices feel usable. At a high level, you can think of it as a manager that keeps many moving parts working together. The kernel sits at the core. It has special power and speaks directly to the processor, memory, and devices. Everything outside the kernel lives in user space, where apps run with fewer privileges. That separation helps keep the system safe and stable. ...

Understanding Operating Systems: The Backbone of Modern Computing An operating system, or OS, is the software that coordinates a computer’s hardware and runs programs. It acts as a traffic manager, giving each task time on the CPU, and providing access to memory, storage, and devices without conflicts. In short, the OS makes all other software usable. The OS has several main parts. The kernel is the core, fast and careful with system resources. User space holds applications, from web browsers to games. Device drivers talk to hardware like printers and disks. System libraries offer helpful functions for developers, so apps don’t need to handle low-level details every time. ...

Fundamentals of Operating Systems Scheduling Revisited Scheduling is a core task of any operating system. It decides which process runs next and for how long. A good scheduler improves interactive responsiveness, keeps servers busy, and avoids long waits for background tasks. This revisit keeps the basics clear while noting practical choices for real systems. Understanding goals helps. Key measures include CPU utilization, turnaround time, waiting time, response time, and overall throughput. These goals trade off with each other. A change that helps one metric may slow another. For users, small, predictable delays beat occasional long stalls. ...

A Practical Guide to Operating Systems for Programmers As a programmer, you rely on an operating system every day. Understanding how it handles processes, memory, and I/O can save time and reduce bugs. This guide gives practical ideas you can use at work and on your own machines. Understanding the basics helps when you troubleshoot or optimize code. Start with a simple model: the kernel runs your programs in user space, schedules CPU time, and mediates access to memory and devices. Different OS families share these ideas, but their details matter for debugging and performance. ...