Operating Systems

Inside Operating Systems: How Modern Kernels Manage Resources When you run apps, the kernel quietly coordinates CPU time, memory pages, disk input and output, and network traffic. Modern kernels aim to keep programs responsive, use hardware efficiently, and protect the system from crashes. They do this with a set of rules and tricks that happen mostly out of sight. How the CPU is shared The kernel uses a scheduler to decide which task runs next. It places tasks in run queues and gives them small time slices. If a task finishes its slice or waits for something, another task takes its turn. Most kernels use a mix of fair scheduling, priority hints, and sometimes random checks to avoid stuck processes. The goal is simple: keep interactive apps smooth while still giving background work a fair share of CPU time. ...

Operating Systems Core Concepts for Developers Computers run many tasks at once, and the operating system (OS) coordinates them. For developers, knowing how the OS handles processes, memory, files, and input/output helps write faster, safer, and more portable code. This guide covers the essentials in plain terms, with practical ideas you can apply today. Processes and threads A process is an isolated program in memory. It has its own space for code and data. A thread is a lightweight path of execution inside a process. Threads share the process resources, which makes communication easier but requires care to avoid conflicts. The OS switches between tasks (context switching) to give fair CPU time. This switching adds overhead, so good design minimizes unnecessary context changes. Memory management and virtual memory ...

Understanding Process Scheduling in Modern OS In modern operating systems, many programs run at once. The CPU is fast, but it is not infinite. The job of the scheduler is to pick which task runs now and for how long. Good scheduling helps your computer feel responsive, saves power, and keeps important tasks on time. Behind the scenes, the OS tracks each task with a small data block that holds its priority, how much CPU time it has used, and what it is waiting for. Tasks move between states such as running, ready, or waiting for input. The scheduler looks at these signals and decides who should run next. ...

Performance Tuning in Operating Systems Performance tuning in an operating system means adjusting settings so the system uses hardware more efficiently. The goal is faster, smoother responses and predictable behavior under load. Start by identifying your workload: a database, a web front end, or a batch job will need different tuning choices. Measure first. Collect data over typical days and during peak periods. Useful tools include top or htop for CPU load, iostat or vmstat for I/O and memory, sar for trends, and perf to inspect CPU events. Look for high I/O wait, memory pressure, or frequent context switches. Your measurements guide the changes, not guesswork. ...

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. ...

What Is an Operating System and How It Works An operating system (OS) is the main software that runs a computer. It coordinates hardware like the CPU, memory, storage, and input/output devices, and it lets other programs run. In short, the OS makes a computer usable. Two big parts make up most OS software: the kernel and user space. The kernel is the central core; it talks directly to hardware and manages essential tasks. User space holds applications, utilities, and services that people interact with. ...

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. ...

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. ...