Kernelsäikeiden

Kernelsäikeiden, often translated as kernel threads, are threads that are managed directly by the operating system kernel. Unlike user-level threads, which are managed by a user-space library and are invisible to the kernel, kernel threads are known to the operating system. This means the kernel can schedule them, manage their execution, and handle their synchronization directly.

When a process makes a system call that requires blocking, such as waiting for I/O, a kernel thread can be used to perform that operation. This allows the main process to continue executing other tasks without being stalled. In multi-processor systems, kernel threads enable true parallelism, as different kernel threads can run on different CPU cores simultaneously.

The primary advantage of kernel threads is their ability to be scheduled independently by the operating system, leading to better performance and responsiveness, especially for I/O-bound or parallelizable tasks. However, creating and managing kernel threads incurs more overhead than user-level threads due to the involvement of the kernel. Context switching between kernel threads is also more expensive than switching between user-level threads within the same process. Despite this, for modern operating systems and complex applications, kernel threads are a fundamental component for efficient multitasking and concurrency.