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First come, first served (FCFS)

This is a non-preemptive technique. A single queue of ready processes is maintained, and the dispatcher always picks the first one. This method does not emphasises throughput, since long processes are allowed to monopolise CPU, For the same reason, the response time with FCFS can be high (with respect to execution time), especially if there is a high variance in process execution times. It's fairly obvious that this method penalises short processes following long ones, though no starvation is possible.



Franco Callari