1
GATE CSE 2015 Set 3
+2
-0.6
For the processes listed in the following table, which of the following scheduling schemes will give the lowest average turnaround time?

Process Arrival Time Processing Time
A 0 3
B 1 6
D 4 4
E 6 2

A
First Come First Serve
B
Non-preemptive Shortest Job First
C
Shortest Remaining Time
D
Round Robin with Quantum value two
2
GATE CSE 2014 Set 1
Numerical
+2
-0
Consider the following set of processes that need to be scheduled on a single $$CPU.$$ All the times are given in milliseconds.
Process Name Arrival Time Execution Time
A 0 6
B 3 2
C 5 4
D 7 6
E 10 3

Using the $$shortest$$ $$remaining$$ $$time$$ $$first$$ scheduling algorithm, the average process turnaround time (in $$msec$$) is _______.

3
GATE CSE 2014 Set 3
Numerical
+2
-0
An operating system uses $$shortest$$ $$remaining$$ $$time$$ $$first$$ scheduling algorithm for pre-emptive scheduling of processes. Consider the following set of processes with their arrival times and $$CPU$$ burst times (in milliseconds):
Process Arrival Time Burst Time
P1 0 12
P2 2 4
P3 3 6
P4 8 5

The average waiting time (in milliseconds) of the processes is ________.

4
GATE CSE 2014 Set 2
Numerical
+2
-0
Three processes $$A, B$$ and $$C$$ each execute a loop of $$100$$ iterations. In each iteration of the loop, a process performs a single computation that requires $${t_c}\,\,CPU$$ milliseconds and then initiates a single $${\rm I}/O$$ operation that lasts for $${t_{io}}$$ milliseconds. It is assumed that the computer where the processes execute has sufficient number of $${\rm I}/O$$ devices and the $$OS$$ of the computer assigns different $${\rm I}/O$$ devices to each process. Also, the scheduling overhead of the $$OS$$ is negligible. The processes have the following characteristics:
Process id tc tio
A 100 ms 500 ms
B 350 ms 500 ms
C 200 ms 500 ms

The processes $$A, B,$$ and $$C$$ are started at times $$0, 5$$ and $$10$$ milliseconds respectively, in a pure time sharing system (round robin scheduling) that uses a time slice of $$50$$ milliseconds. The time in milliseconds at which process $$C$$ would complete its first $${\rm I}/O$$ operation is __________.