GATE CS Operating System questions

Practise Operating System questions for GATE CS. Explore official PYQs and original subject-wise quizzes, check answers and view available solutions. Free, no sign-in.

Trace the state changes explicitly. For scheduling, memory and synchronisation questions, record the given policy before calculating the result.

18 on this page

SubjectTopicYearType

The address sequence generated by tracing a particular program executing in a pure demand based paging system with

100

records per page with

1

free main memory frame is recorded as follows. What is the number of page faults?

0100, 0200, 0430, 0499, 0510, 0530, 0560, 0120, 0220, 0240, 0260, 0320, 0370

The sequence __________ is an optimal non-preemptive scheduling sequence for the following jobs which leaves the CPU idle for ________ unit(s) of time. …

Which scheduling policy is most suitable for a time shared operating system?

Which of the following page replacement algorithms suffers from Belady’s anamoly?

In a paged segmented scheme of memory management, the segment table itself must have a page table because

Consider the following heap (figure) in which blank regions are not in use and hatched region are in use. The sequence of requests for blocks of sizes

300, 25, 125, 50

can be satisfied if we use

Which one of the following statements is true?

A memory page containing a heavily used variable that was initialized very early and is in constant use is removed then

Assume that the following jobs are to be executed on a single processor system

\begin{array}{|c|c|} \hline \textbf{Job Id} & \textbf{CPU Burst Time} \\ \hline \text{p} & 4 \\ \hline \text{q} & 1 \\ \hline \text{r} & 8 \\ \hline \text{s} & 1 \\ \hline \text{t} & 2 \\ \hline \end{array}

The jobs are assumed to have arrived at time …

Consider a system having

m

resources of the same type. These resources are shared by

3

processes

A, B

, and

C

which have peak demands of

3, 4

, and

6

respectively. For what value of

m

deadlock will not occur?

The root directory of a disk should be placed

The details of an interrupt cycle are shown in figure. Given that an interrupt input arrives every

1

msec, what is the percentage of the total time that the CPU devotes for the main program execution.

Which of the following is an example of a spooled device?

A computer system has

6

tape devices, with n processes competing for them. Each process may need

3

tape drives. The maximum value of n for which the system is guaranteed to be deadlock-free is:

At a particular time of computation, the value of a counting semaphore is

7

. Then

20

P

operations and

15

V

operations were completed on this semaphore. The resulting value of the semaphore is :

Indicate all the false statements from the statements given below:

In a two-level virtual memory, the memory access time for main memory,

t_{M}=10^{-8}

sec, and the memory access time for the secondary memory,

t_D=10^{-3}

sec. What must be the hit ratio,

H

such that the access efficiency is within

80

percent of its maximum value?

A critical region is