Operating Systems | CPU Scheduling | Question 1
Consider three processes (process id 0, 1, 2 respectively) with compute time bursts 2, 4 and 8 time units. All processes arrive at time zero. Consider the longest remaining time first (LRTF) scheduling algorithm. In LRTF ties are broken by giving priority to the process with the lowest process id. The average turn around time is:
(A) 13 units
(B) 14 units
(C) 15 units
(D) 16 units
Explanation: Let the processes be p0, p1 and p2. These processes will be executed in following order.
p2 p1 p2 p1 p2 p0 p1 p2 p0 p1 p2 0 4 5 6 7 8 9 10 11 12 13 14
Turn around time of a process is total time between submission of the process and its completion.
Turn around time of p0 = 12 (12-0)
Turn around time of p1 = 13 (13-0)
Turn around time of p2 = 14 (14-0)
Average turn around time is (12+13+14)/3 = 13.
Quiz of this Question
Attention reader! Don’t stop learning now. Get hold of all the important CS Theory concepts for SDE interviews with the CS Theory Course at a student-friendly price and become industry ready.