GATE CS CPU Scheduling questions

Consider a CPU that has to execute two types of processes. The first type, Actuators (A), requires a CPU burst of $6$ seconds. The second type, Controllers (C), requires a CPU burst of $8$ seconds. A new process of type A arrives at time $t=10$, $20, 30, 40$, and $50$ (in seconds). Similarly, a new process of type C arrives at time $t=$ …

Which one of the following CPU scheduling algorithms cannot be preemptive?

Suppose in a multiprogramming environment, the following C program segment is executed. A process goes into I/O queue whenever an I/O related operation is performed. Assume that there will always be a context switch whenever a process requests for an I/O, and also whenever the process returns from an I/O. The number of times the process will enter the ready …

A computer has two processors, $M_{1}$ and $M_{2}$. Four processes $P_{1}, P_{2}, P_{3}, P_{4}$ with CPU bursts of $20,16,25$, and $10$ milliseconds, respectively, arrive at the same time and these are the only processes in the system. The scheduler uses non-preemptive priority scheduling, with priorities decided as follows: $M_{1}$ uses priority …

​​​Processes $P 1, P 2, P 3, P 4$ arrive in that order at times $0,1,2$, and 8 milliseconds respectively, and have execution times of $10,13,6$, and 9 milliseconds respectively. Shortest Remaining Time First (SRTF) algorithm is used as the CPU scheduling policy. Ignore context switching times. Which ONE of the following correctly gives the average …

Which of the following process state transitions is/are NOT possible?

​​​​Consider a single processor system with four processes $\text{A, B, C,}$ and $\text{D}$, represented as given below, where for each process the first value is its arrival time, and the second value is its $\text{CPU}$ burst time. $\mathrm{A}(0,10), \mathrm{B}(2,6), \mathrm{C}(4,3)$, and $\mathrm{D}(6,7)$. Which one of the following options …

Which one or more of the following $\text{CPU}$ scheduling algorithms can potentially cause starvation?

Consider four processes $\text{P, Q, R,}$ and $\text{S}$ scheduled on a $\text{CPU}$ as per round robin algorithm with a time quantum of $4\text{ units.}$ The processes arrive in the order $\text{P, Q, R, S,}$ all at time $\text{t = 0}.$ There is exactly one context switch from $\text{S}$ to $\text{Q},$ exactly one context switch from …

Three processes arrive at time zero with $\text{CPU}$ bursts of $16,\;20$ and $10$ milliseconds. If the scheduler has prior knowledge about the length of the $\text{CPU}$ bursts, the minimum achievable average waiting time for these three processes in a non-preemptive scheduler (rounded to nearest integer) is _____________ milliseconds.

Which of the following statement(s) is/are correct in the context of $\text{CPU}$ scheduling?

Consider the following statements about process state transitions for a system using preemptive scheduling. A running process can move to ready state. A ready process can move to running state. A blocked process can move to running state. A blocked process can move to ready state. Which of the above statements are TRUE?

Consider the following set of processes, assumed to have arrived at time $0$. Consider the CPU scheduling algorithms Shortest Job First (SJF) and Round Robin (RR). For RR, assume that the processes are scheduled in the order$P_1, P_2, P_3, P_4$. …

Consider the following four processes with arrival times (in milliseconds) and their length of CPU bursts (in milliseconds) as shown below: …

Consider the following CPU processes with arrival times (in milliseconds) and length of CPU bursts (in milliseconds) as given below: …

Consider the set of process with arrival time (in milliseonds), CPU burst time (in millisecods) and priority ($0$ is the highest priority) shown below. None of the process have I/O burst time …

Consider an arbitrary set of CPU-bound processes with unequal CPU burst lengths submitted at the same time to a computer system. Which one of the following process scheduling algorithms would minimize the average waiting time in the ready queue?

Consider the following processes, with the arrival time and the length of the CPU burst given in milliseconds. The scheduling algorithm used is preemptive shortest remaining-time first. …

Consider a uniprocessor system executing three tasks $T_{1}, T_{2}$ and $T_{3}$ each of which is composed of an infinite sequence of jobs (or instances) which arrive periodically at intervals of $3, 7$ and $20$ milliseconds, respectively. The priority of each task is the inverse of its period, and the available tasks are scheduled in order of …

For the processes listed in the following table, which of the following scheduling schemes will give the lowest average turnaround time? …