(also context switch)
Preemption refers to briefly pausing a task without asking for its consent to resume it later. Usually, the preemptive scheduler, an operating system element with authority to interrupt and resume tasks executing within the system, carries out this action. Preemption often interrupts the execution of lower-priority tasks and promptly addresses critical tasks. It enables the system to allocate resources efficiently, ensuring optimal performance and resource management.
- Preemption improves system responsiveness by allocating resources to high-priority tasks, ensuring the system effectively addresses urgent processes.
- It prevents lower-priority tasks from monopolizing resources for extended periods, thereby ensuring fair system resource allocation.
- By efficiently allocating CPU time and memory, preemption helps in optimal resource management.
- It facilitates multitasking in computer systems by enabling multiple tasks to execute concurrently without significant performance degradation.
- Context switching might introduce additional overhead, which can affect overall system performance.
- Implementing a preemptive scheduler can be complex.
- It increases the chances of bugs and maintenance difficulties in the operating system.
- Lower-priority tasks may suffer if they are constantly preempted by higher-priority tasks and never get the chance to be executed.