Linux

Introduction If you have ever peered into a running Linux system with tools like top, htop, or ps, you might have noticed a set of processes named kworker/*. These processes are not user‑space daemons; they are kernel threads that drive the workqueue subsystem, a core mechanism that lets the kernel defer work to a later time or to a different context. Understanding kworker is essential for anyone who: Writes kernel modules or device drivers. Diagnoses performance or latency problems on Linux servers, embedded devices, or real‑time systems. Wants to comprehend how the kernel handles asynchronous I/O, timers, and deferred work. This article dives deep into the architecture, APIs, practical usage, debugging techniques, and performance considerations surrounding kworker. By the end, you’ll be able to: ...

Introduction When you log into a Unix or Linux system over SSH, you’re essentially opening a session that is bound to a controlling terminal. As long as that terminal exists, the kernel delivers signals—most notably SIGHUP (hang‑up)—to every process that belongs to the session. If the terminal disappears (for example, you close your SSH client or lose network connectivity), the kernel sends SIGHUP to the foreground and background jobs, and many of those jobs terminate by default. ...

Introduction If you spend any amount of time in a Unix‑like shell, you’ve probably heard the terms tmux and screen whispered in the corridors of DevOps, system administration, and software development. Both are terminal multiplexers: programs that let you run multiple terminal sessions within a single physical terminal, detach from them, and reattach later—often from a completely different machine. Why does this matter? Because modern work is increasingly remote, distributed, and interrupted. You might be hopping on a VPN, switching between laptops, or getting pulled away for a meeting. Without a multiplexer, every time you lose your SSH connection you lose the state of every interactive program you were running (vim, top, a REPL, a long‑running build, etc.). With tmux or screen, those programs keep running in the background, and you can pick up exactly where you left off. ...

Introduction When a Linux system runs out of memory, the kernel must decide which processes to terminate to reclaim RAM and keep the machine alive. That decisive, sometimes brutal, component is the Out‑Of‑Memory (OOM) Killer. While most users never see it in action, administrators, developers, and anyone who runs workloads on servers, virtual machines, or containers will eventually encounter it—especially under heavy load, memory leaks, or mis‑configured resource limits. This article provides an in‑depth, practical guide to the OOM Killer: ...

Introduction Whether you’re a developer, sysadmin, data scientist, or just curious about the command line, knowing the right Linux commands can save time and help you work more confidently. This guide covers the 50 most useful Linux commands, grouped by category, with concise explanations and copy‑paste‑ready examples. It focuses on commands available on most modern distributions and highlights best practices and safety tips along the way. Tip: Nearly every command supports a --help flag and has a manual page you can read with man. When in doubt, check command --help or man command. ...