KontextwechselZeiten

KontextwechselZeiten, often translated as context switching time, refers to the overhead incurred by a computing system when it changes from executing one task or process to another. This overhead is not related to the actual work performed by the tasks themselves but rather the time spent by the operating system and hardware to save the state of the current task, load the state of the new task, and prepare the system to execute the new task.

When a processor switches context, it needs to store the registers, program counter, and other essential information of the currently running process. This information is typically saved in a data structure known as a Process Control Block (PCB) or Task Control Block (TCB). After saving, the system loads the corresponding information for the next process from its PCB/TCB. This process involves writing data to and reading data from memory, which takes a measurable amount of time.

High context switching times can significantly impact system performance. Frequent context switching, often caused by a large number of processes competing for CPU resources or inefficient scheduling algorithms, can lead to a substantial portion of the CPU's time being spent on switching rather than doing useful work. This phenomenon is sometimes referred to as "thrashing" in the context of operating system performance. Minimizing context switching time is therefore a crucial aspect of operating system design and performance optimization. Factors influencing context switching time include the complexity of the operating system's scheduler, the speed of memory access, and the architecture of the processor.