kjernetråd

A kjernetråd, translating to "core thread" or "kernel thread" in English, refers to a low-level thread of execution managed directly by the operating system kernel. Unlike user-level threads, which are managed by a user-level library and are multiplexed onto one or more kernel threads, kernel threads are the fundamental units of scheduling for the operating system.

When the operating system kernel creates a kernel thread, it assigns it a dedicated entry in the kernel's scheduler. This means the kernel is aware of each individual kernel thread and can directly allocate CPU time to it. This direct management allows for more efficient scheduling, as the kernel can make informed decisions about resource allocation based on the actual needs of each thread.

Key characteristics of kernel threads include their direct mapping to processor cores, their ability to make system calls independently, and their support for preemptive multitasking. If one kernel thread blocks on an I/O operation or other kernel-level event, other kernel threads can continue to run on different processor cores or be scheduled by the kernel. This direct kernel involvement provides a robust and efficient foundation for multitasking and concurrency within an operating system. Most modern operating systems, such as Linux, Windows, and macOS, utilize kernel threads as the primary mechanism for managing concurrent execution.