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Recent questions tagged operating-system

3 votes
2 answers
1
Which of the following is incorrect for virtual memory? Large programs can be written More I/O is required More addressable memory available Faster and easy swapping of process
asked Mar 24 in Operating System jothee 117 views
0 votes
1 answer
2
A memory management system has $64$ pages with $512$ bytes page size. Physical memory consists of $32$ page frames Number of bits required in logical and physical address are respectively: $14$ and $15$ $14$ and $29$ $15$ and $14$ $16$ and $32$
asked Mar 24 in Operating System jothee 183 views
0 votes
1 answer
3
Consider a disk queue with I/O requests on the following cylinders in their arriving order: $6,10,12,54,97,73,128,15,44,110,34,45$. The disk head is assumed to be at cylinder $23$ and moving in the direction of decreasing number of cylinders. Total number of cylinders in the disk is $150$. The disk head movement using SCAN –scheduling algorithm is: $172$ $173$ $227$ $228$
asked Mar 24 in Operating System jothee 117 views
0 votes
0 answers
4
0 votes
1 answer
5
Some of the criteria for calculation of priority of a process are: Processor utilization by an individual process. Weight assigned to a user or group of users Processor utilization by a user or group of processes In fair scheduler, priority is calculated based on: only (a) and (b) only (a) and (c) (a) ,(b) and (c) only (b) and (c)
asked Mar 24 in Operating System jothee 123 views
0 votes
1 answer
6
One of the disadvantages of user level threads compared to Kernel level thread is If a user level thread of a process executes a system call, all threads in that process are blocked. Scheduling is application dependent. Thread switching doesn’t require kernel mode privileges. The library procedures invoked for thread management in user level threads are local procedures.
asked Mar 24 in Operating System jothee 90 views
0 votes
0 answers
7
Which statements is not correct about “init” process in Unix? It is generally the parent of the login shell. It has PID $1$. It is the first process in the system. Init forks and execs a ‘getty’ process at every port connected to a terminal.
asked Mar 24 in Operating System jothee 47 views
0 votes
0 answers
8
Names of some of the Operating Systems are given below: MS-DOS XENIX OS/$2$ In the above list, following operating systems didn’t provide multiuser facility. (a) only (a) and (b)only (b) and (c) only (a),(b) and (c)
asked Mar 24 in Operating System jothee 20 views
0 votes
2 answers
10
In a paging system, it takes $30$ ns to search translation Look-a-side Buffer (TLB) and $90$ ns to access the main memory. If the TLB hit ratio is $70\%$, the effective memory access time is : $48$ ns $147$ns $120$ns $84$ns
asked Mar 24 in Operating System jothee 65 views
0 votes
2 answers
11
0 votes
3 answers
12
Which of the following scheduling algorithms may cause starvation ? First-come-first-served Round Robin Priority Shortest process next Shortest remaining time first a, c and e c, d and e b, d and e b, c and d
asked Mar 24 in Operating System jothee 55 views
0 votes
1 answer
13
Distributed operating systems consist of: Loosely coupled O.S. software on a loosely coupled hardware. Loosely coupled O.S. software on a tightly coupled hardware. Tightly coupled O.S. software on a loosely coupled hardware. Tightly coupled O.S. software on a tightly coupled hardware.
asked Mar 24 in Operating System jothee 25 views
3 votes
4 answers
14
Consider allocation of memory to a new process. Assume that none of the existing holes in the memory will exactly fit the process's memory requirement. Hence, a new hole of smaller size will be created if allocation is made in any of the existing holes. Which one of ... never larger than the hole created by first fit. The hole created by next fit is never larger than the hole created by best fit.
asked Feb 12 in Operating System Arjun 1.7k views
3 votes
6 answers
15
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? I, II, and III only II and III only I, II, and IV only I, II, III and IV only
asked Feb 12 in Operating System Arjun 2.1k views
5 votes
4 answers
16
Each of a set of $n$ processes executes the following code using two semaphores $a$ and $b$ initialized to $1$ and $0$, respectively. Assume that $\text{count}$ is a shared variable initialized to $0$ ... ensures that all processes execute CODE SECTION P mutually exclusively. It ensures that at most $n-1$ processes are in CODE SECTION P at any time.
asked Feb 12 in Operating System Arjun 2k views
2 votes
2 answers
17
Consider the following five disk five disk access requests of the form (request id, cylinder number) that are present in the disk scheduler queue at a given time. $(P, 155), (Q,85), (R,110),(S, 30), (T,115)$ Assume the head is positioned at cylinder $100$. The ... $S$,but before $T$. The head reverses its direction of movement between servicing of $Q$ and $P$. $R$ is serviced before $P$.
asked Feb 12 in Operating System Arjun 1.1k views
3 votes
3 answers
18
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$P_1, P_2, P_3, P_4$ ... absolute value of the difference between the average turnaround times (in ms) of SJF and RR (round off to $2$ decimal places is_______
asked Feb 12 in Operating System Arjun 1.4k views
12 votes
10 answers
19
Consider a paging system that uses $1$-level page table residing in main memory and a TLB for address translation. Each main memory access takes $100$ ns and TLB lookup takes $20$ ns. Each page transfer to/from the disk takes $5000$ ns. Assume that the TLB hit ... is read from disk. TLB update time is negligible. The average memory access time in ns (round off to $1$ decimal places) is ___________
asked Feb 12 in Operating System Arjun 5.7k views
1 vote
2 answers
20
Jobs keep arriving at a processor. A job can have an associated time length as well as a priority tag. New jobs may arrive while some earlier jobs are running. Some jobs may keep running indefinitely. A ... the following job-scheduling policies is starvation free? Round - robin Shortest job first Priority queuing Latest job first None of the others
asked Feb 11 in Operating System Lakshman Patel RJIT 147 views
3 votes
3 answers
21
The hardware implementation which provides mutual exclusion is Semaphores Test and set instructions Both options None of the options
asked Jan 13 in Operating System Satbir 888 views
2 votes
4 answers
22
The operating system and the other processes are protected from being modified by an already running process because they run at different time instants and not in parallel they are in different logical addresses they use a protection algorithm in the scheduler every address generated by the CPU is being checked against the relocation and limit parameters
asked Jan 13 in Operating System Satbir 493 views
1 vote
3 answers
23
What is compaction refers to a technique for overcoming internal fragmentation a paging technique a technique for overcoming external fragmentation a technique for compressing the data
asked Jan 13 in Operating System Satbir 575 views
2 votes
1 answer
24
Three CPU-bound tasks, with execution times of $15,12$ and $5$ time units respectively arrive at times $0,t$ and $8$, respectively. If the operating system implements a shortest remaining time first scheduling algorithm, what should be the value of $t$ to have $4$ context switches? Ignore the context switches at time $0$ and at the end. $0<t<3$ $t=0$ $t<=3$ $3<t<8$
asked Jan 13 in Operating System Satbir 460 views
2 votes
2 answers
25
Consider the following page reference string. $1\ 2\ 3\ 4\ 2\ 1\ 5\ 6\ 2\ 1\ 2\ 3\ 7\ 6\ 3\ 2\ 1\ 2\ 3\ 6\ $ What are the minimum number of frames required to get a single page fault for the above sequence assuming LRU replacement strategy? $7$ $4$ $6$ $5$
asked Jan 13 in Operating System Satbir 869 views
1 vote
2 answers
26
An aid to determine the deadlock occurrence is resource allocation graph starvation graph inversion graph none of the above
asked Jan 13 in Operating System Satbir 329 views
1 vote
1 answer
27
Dispatch latency is defined as the speed of dispatching a process from running to the ready state the time of dispatching a process from running to ready state and keeping the CPU idle the time to stop one process and start running another one none of these
asked Jan 13 in Operating System Satbir 485 views
2 votes
1 answer
28
Which of the following algorithms defines time quantum? shortest job scheduling algorithm round robin scheduling algorithm priority scheduling algorithm multilevel queue scheduling algorithm
asked Jan 13 in Operating System Satbir 962 views
1 vote
0 answers
29
2 votes
1 answer
30
In certain countries, when two people meet they bow to each other. The protocol is that one of them bows first and stays down until the other one bows. If they bow at the same time, they will both stay bowed forever. Write a program that does not deadlock.
asked Oct 30, 2019 in Operating System Lakshman Patel RJIT 192 views
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