# Recent questions tagged process-scheduling

1
Process is in a ready state _______ . when process is scheduled to run after some execution when process is unable to run until some task has been completed when process is using the $CPU$ none of the options
2
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 $13$ units $14$ units $15$ units $16$ units
3
Consider three processes, all arriving at time zero, with total execution time of $10,20$ and $30$ units, respectively. Each process spends the first $20\%$ of execution time doing I/O, the next $70\%$ of time doing computation, and the last $10\%$ of time doing I/O again. The ... as much as possible. For what percentage of time does the CPU remain idle? $0\%$ $10.6\%$ $30.0\%$ $89.4\%$
4
Consider three CPU-intensive processes, which require $10,20$ and $30$ time units and arrive at times $0,2$ and $6$, respectively. How many context switches are needed if the operating system implements a shortest remaining time first scheduling algorithm? Do not count the context switches at time zero and at the end. $1$ $2$ $3$ $4$
5
Which of the following process scheduling algorithm may lead to starvation? FIFO Round Robin Shortest Job Next None of the option
6
A scheduling algorithm assigns priority proportional to the waiting time of a process. Every process starts with priority zero (the lowest priority). The scheduler re-evaluates the process priorities every $T$ time units and decides the next process to ... algorithm is equivalent to the shortest-job-first algorithm. This algorithm is equivalent to the shortest-remaining time-first algorithm.
7
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)
8
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
9
Consider a system in which it is desired to separate policy and mechanism for the scheduling of kernel threads. Propose a means of achieving this goal.
10
Round-robin schedulers normally maintain a list of all runnable processes, with each process occurring exactly once in the list. What would happen if a process occurred twice in the list? Can you think of any reason for allowing this?
11
Does Peterson’s solution to the mutual-exclusion problem shown in Fig. $2-24$ work when process scheduling is preemptive? How about when it is nonpreemptive?
1 vote
12
A context switch from a process $P_{old}$ to a process $P_{new}$ consists of the following steps: Step I:saving the context of $P_{old}$; Step II: running the scheduling algorithm to pick $P_{new}$; Step III: restoring the saved context of $P_{new}$. Suppose Steps I and ... same instant in the order $P_1, P_2, . . . , P_k;$ each process requires exactly one CPU burst of $20$ms and no I/O burst.
13
Please help me explaining this in simpler words: If we were to swap out process P1 and swap in process P2, the I/O operation might then attempt to use memory that now belongs to process P2. There are two main solutions to this problem: never swap ... operating-system buffers and process memory then occur only when the process is swapped in. Note that this double buffering itself adds overhead.
14
Consider we have a cpu whose processes are scheduled using premptive priority scheduling algorithm, suppose a process of higher priority than the currently running process arrives in the ready queue, according to the algorithm the running process must be prempted, who actually does this job of interrupting the running process?
15
Consider the following four processes with arrival times (in milliseconds) and their length of CPU bursts (in milliseconds) as shown below: ... Shortest Remaining Time First scheduling algorithm. If the average waiting time of the processes is $1$ millisecond, then the value of $Z$ is _____
16
Does increasing number of threads decrease total waiting time of the process in terms of round robin scheduling or does it remain the same? Can you please explain why
17
18
How to solve this question?
19
Identify Correct Statements : A. Forked Process shares the address space and other resources with parent. B. Forked Process can't use multiprocessor for parallel execution. C. Security is better in Process in comparison to threads. D. Thread switching doesn't require Kernel Support unlike threads. Explain Everyone of them (Mulitiple choices can be present)
20
In round robin scheduling, which process gets the chance first if a process comes to ready state from running(i.e time quantom getting over) and another from new to ready(i.e due to same arrival time) ? Is there a convention or will it be specified in the question?
21
Consider the following set of processes and the length of CPU burst time given in milliseconds : ... being scheduled with Round-Robin Scheduling Algorithm with time quantum $4$ ms. Then the waiting time for $P_4$ is ______ ms $0$ $4$ $12$ $6$
22
For the given question instead of the given order if we take one unit of P2 as its arrival time is 1 and then schedule P1 next we get the same answer,even in the hint they have given as the process which comes first should get first priority instead in ... first.My approach and the solution given ends up giving the same answer,does this happen for all cases or just happening for this question?
23
ANSWER IS C) BUT I AM NOT GETTING HOW 2ND IS CORRECT
24
Dispatcher module gives control of the CPU to the process selected by the short-term scheduler; thisinvolves 1 switching context 2.jumping to the proper location in the user program to restart that program 3 switching to user mode 4. All the above ANSWER IS D I AM NOT GETTING 2 AND 3
25
CPU bound jobs will hold CPU until exit or I/O. Long periods where no I/O requests issued, and theCPU is held resulting in poor I/O device utilization. This degradation in performance can be seen inwhich of the following? (A)SJF ( B) RR (C)FCFS (D)SRTF
Consider the following table: Pid BT I/O BT $P_0$ 6 4 1 $P_1$ 8 6 2 $P_2$ 12 8 3 Using the shortest remaining time first, find the completion time of a process P2 , if the context switching overhead is 1 unit 36 48 47 37 In these question i am getting 48 ... 1 unit when P2 finishes it's io at 44 unit , please tell me that is it required to consider the context switching time here just see it