Prosessutnyttelse

Prosessutnyttelse refers to the degree to which a system resource is actively used by processes during a given time period. In computing, the term is most commonly applied to CPU utilization, but it can also describe how effectively other resources, such as I/O channels or memory, are used by running processes. Utnyttelsen is typically expressed as a percentage of time during which the resource is busy relative to the observation window.

Measurement and interpretation commonly involve monitoring tools that report metrics like busy time and total observation time. A simple formula is util = (time the resource is busy) / (total observation time) × 100%. Measurements often distinguish between user mode, system (kernel) mode, and I/O wait, providing a fuller picture of where time is spent.

Several factors influence prosessutnyttelse. Antall aktive prosesser, whether they are CPU-bound or I/O-bound, and the efficiency of the process scheduler affect how well the CPU is kept busy. Context switching, synchronicity, and contention for shared resources can introduce overhead that reduces effective utilization. I/O blocking or delays can also lower perceived utilization even when processing power is available.

High ut nyttelse is not always desirable. Very high or peak utilization may indicate saturation and potential bottlenecks, leading to increased latency or failed tasks. Conversely, very low utilization signals underutilization of hardware resources and inefficiency. Optimal levels depend on workload and system design; typical aims include avoiding prolonged idle times while preventing excessive queuing and contention.

Strategies to improve utilization include better load balancing, tuning of scheduling policies, parallelization of tasks, increasing parallel hardware resources, reducing I/O bottlenecks, and employing asynchronous or non-blocking I/O. Regular monitoring helps maintain a stable and efficient level of prosessutnyttelse.