CSE 120 Lecture Notes - Lecture 4: Priority Queue
23 Jan 2018
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Arrival time - time that process is created. Service time - cpu time needed to complete! Given n processes with service times s 1 , , s n. [s 1 + (s 1 + s 2 ) + + (s 1 + + s n )] / n. [(n x s 1 ) + ((n-1) x s 2 ) + ((n-2) x s 3 ) + + (1 x s n )] / n. That means to achieve minimal tt, we want to choose the process with the shortest service time. Allocate cpu to processes in order of arrival. + non-preemptive (cpu not taken away from a process) +no starvation - whenever a process can get the resources it needs. Cycle through processes in the queue (recent processes are entered in the back) Preemptive - need a mechanism that takes away the cpu. Select next process to run w/ the shortest service time.
