Kernel

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 ...

A Gentle Introduction to Operating Systems and How They Work An operating system (OS) is the software that helps all other programs run smoothly. It sits between your apps and the computer’s hardware. When you start a browser or a game, the OS decides who gets the CPU time, keeps memory organized, and talks to devices like the keyboard and screen. How an OS fits in Think of a computer as a busy kitchen. The CPU is the cook, memory is the pantry, and devices are tools. The OS acts as the kitchen manager. It schedules tasks, protects each program’s space, and provides a simple way for programs to ask for help. ...

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. ...

Operating Systems in Practice From Boot to Shutdown From power on to power off, an operating system coordinates work across hardware and software. This guide explains the practical journey, with everyday examples you can relate to at work or home. Boot and Initialization When you press the power button, firmware runs a quick check and hands control to a bootloader. The bootloader loads the kernel and a minimal set of drivers, plus an initial user-space environment (initramfs or initrd). In Linux, GRUB or systemd-boot loads the kernel image and then starts the first process. In Windows, the boot manager loads the kernel and core services in stages. The early phase sets up memory, devices, and essential services so the rest of the system can operate. ...

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. ...

Behind the Scenes of Operating Systems: From Kernels to Interfaces Operating systems sit between programs and hardware. They manage memory, schedule tasks, handle input and output, and present a practical interface to software. Think of an OS as a city: the kernel acts as the central planner and service hub, while applications run in their own neighborhoods in user space. The result is a stable, responsive environment for many programs at once. ...

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. ...

Operating Systems Demystified: Inside the Kernel to User Space An operating system sits between software and hardware. It manages resources, keeps programs safe, and helps devices talk to each other. In this post we explore the journey from kernel to user space. The goal is to keep ideas clear and useful for daily work, not just theory. The kernel is the system’s brain. It runs in privileged mode and handles CPU scheduling, memory, and I/O devices. It decides who gets to run, when, and for how long. Programs run in user space with normal privileges, which helps protect the system from bad software. ...