Kontekstivahetuse

Kontekstivahetuse, also known as context switching, is a process in computing where the CPU switches from executing one process or thread to another. This is a fundamental aspect of multitasking in operating systems, allowing multiple processes to share the CPU's time and resources. Context switching involves saving the state of the current process, including its program counter, registers, and memory management information, and then loading the state of the next process to be executed.

The primary goal of context switching is to maximize CPU utilization and improve system performance by ensuring that the CPU is not idle while waiting for I/O operations or other processes. However, frequent context switching can lead to overhead, as the CPU spends time saving and loading process states rather than executing instructions. This can degrade overall system performance, especially in systems with a high number of processes or threads.

Operating systems employ various strategies to manage context switching, such as time slicing, where the CPU allocates a fixed amount of time to each process, and priority scheduling, where the CPU switches to the highest priority process available. Additionally, some systems use techniques like lazy context switching, where the state of a process is only saved when it is preempted by a higher-priority process, to reduce the overhead associated with context switching.

In summary, kontekstivahetuse is a crucial mechanism for multitasking in computing, enabling efficient use of the CPU by switching between processes. While it is essential for system performance, it must be managed carefully to minimize overhead and ensure smooth operation.