SysAdmin

  • Zombie Processes: Dead Code That Still Haunts the System

    Zombie Processes: Dead Code That Still Haunts the System

    In operating systems, not every threat is loud. Some are silent, subtle, and buried deep in the process table. Zombie processes fall exactly into that category: tasks that have already finished execution but refuse to disappear. They’re technically dead, yet still present a residue of poor process management that can grow into a system-wide…

  • Optimizing Context Switches in the Linux Kernel: Hidden Performance Leverage

    Optimizing Context Switches in the Linux Kernel: Hidden Performance Leverage

    1. What Context Switching Really Costs Every time the kernel performs a context switch — moving execution from one thread to another — the CPU flushes registers, updates the program counter, and reloads process metadata. This is not “free multitasking.” It burns thousands of CPU cycles.When the switch rate spikes, cache locality is destroyed…