Editing Context switch (section)

=== Multitasking ===
Most commonly, within some [[scheduling (computing)|scheduling]] scheme, one process must be switched out of the CPU so another process can run. This context switch can be triggered by the process making itself unrunnable, such as by waiting for an [[Input/output|I/O]] or [[synchronization (computer science)|synchronization]] operation to complete. On a [[pre-emptive multitasking]] system, the scheduler may also switch out processes that are still runnable. To prevent other processes from being starved of CPU time, pre-emptive schedulers often configure a timer interrupt to fire when a process exceeds its [[time slice]]. This interrupt ensures that the scheduler will gain control to perform a context switch.