Questions tagged [process-scheduling]
Questions about how operating systems decide which process to execute at which time.
27
questions with no upvoted or accepted answers
4
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0answers
425 views
Problems of cyclic executive approach for scheduling of real time systems
I have a doubt on the cyclic executive approach for scheduling on real time systems. From Alan Burns's book Real-time Systems and Programming Languages.
This final property represents one of the ...
3
votes
1answer
510 views
Convoy effect in priority scheduling and SJF (Non preemptive)
In books, I have read that FCFS suffers from convoy effect. I think that even SJF and priority(both preemptive and non preemptive) can suffer from convoy effect.
In SJF, if a process with large burst ...
3
votes
0answers
297 views
Paging: Does the page table of a process also gets swapped out when the process gets swapped out from main memory?
Does a process's page table too gets swapped out to secondary storage from main memory when the process gets swapped out to secondary storage from main memory? And gets swapped back in when the ...
2
votes
0answers
89 views
long-lived scheduling using max-flow & push/relabel
I'm writing a scheduler of long-lived Processors which execute long-lived Tasks. Processors and Tasks may each come and go over time, at any time (when a Processor departs, its assigned Tasks now ...
2
votes
0answers
41 views
Identify common mathematical problem behind my task in scheduling area
Having single operator, which could do work and it's time of availability - for example from 8 am till 9 pm. And operator have limited resource - let's call it ...
2
votes
0answers
40 views
How can I talk about priority inversion if it's impossible to specify priority?
In the paper:
Leslie Lamport: What It Means for a Concurrent Program to
Satisfy a Specification: Why No One Has Specified Priority; ACM Symp Principles of Programming Languages, (POPL-12):78-83, ...
1
vote
0answers
36 views
Expected value of next CPU burst using exponential averaging
The burst time is needed for Shortest Job First (SJF) and Shortest Run Time First (SRTF) scheduling. To get the approximate burst time, we use the equation
$$\tau_{n + 1} = t_n + (1 - \alpha)\tau_n$$
...
1
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0answers
27 views
What approach to solve an open shop problem with following constraints
Say we have an open shop scheduling problem with following constraints :
No wait-time between operations of a job
Multiple job types (meaning each job type has different set of operations eventhough ...
1
vote
0answers
1k views
Difference between Response time, Execution time, and CPU time
I studied Computer Architecture from David A. Patterson and have came across the idea of Response time.
Response time also called Execution time. The total time required for the computer to ...
1
vote
0answers
68 views
Appropriate algorithm or heuristic for task scheduling
I'm sure this problem has been addressed before, but I'm unable to find an exact description of it.
I have $m$ machines, and $n$ tasks that need processing. Each task takes a variable amount of ...
1
vote
0answers
43 views
Scheduling identical jobs with Cmax/Ci
I have $x$ uniform machines that are identical, except that each runs at a different speed; machine $j$ runs at speed $s_j$. I have $n$ identical jobs. Each machine can handle one job at a time. ...
1
vote
0answers
102 views
Processes running in Distributed Systems (Advanced Operating System)
I had a test today, there was a question that was a bit confusing. Anyway I am asking the question, from memory, and explaining what I answered. It would be great if someone could explain if I did ...
1
vote
0answers
270 views
Optimality of EDF
For Earliest Deadline First, I have read that if utilization is less or equal to 1, the task set is schedulable under EDF. But does this criteria expresses the optimality for EDF? If not, how can we ...
1
vote
0answers
115 views
Processes concurrency
I am getting ready for my end of year exams and I got stuck on this question.
Consider the following 3-process concurrent program which uses semaphores S1,
...
0
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0answers
33 views
Advantages of Preemptive Scheduling
I'm currently studying for an exam which includes operating systems. I'm solving the exams from previous years and I'm stuck on a particular question:
"One of the advantages of preemptive scheduling ...
0
votes
0answers
45 views
Process scheduling accounting for multiple factors
I'm attempting to solve a problem that consists of scheduling two types (A and B) of processes to run. The system must be non-preemptive (once a process starts executing it must finish before another ...
0
votes
0answers
9 views
How to do Distributed Job Scheduling after the Leader was elected and slaves are known - (bully)
I'm building a system that processes key,value pairs on a continuous basis in a loop, until terminated.
How do I schedule tasks on the leader and make slaves execute them?
This is a realm of ...
0
votes
1answer
39 views
Calculation of speed up of a program executed in multi-threaded system
Speed up of execution of a program is to be calculated within a multi-threading rather than a single thread system. The program's 30% instruction can be executed serially & rest can be executed ...
0
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0answers
33 views
Segmentation with paging
Question:
A virtual memory system uses both paging and segmentation. Process virtual addresses consist of a total of 32 bits. The page size is 1024 (210) bytes. A page table may occupy at most one ...
0
votes
1answer
67 views
Calculating minimum processing time for many recipes and tools
I originally asked this question on StackOverflow but a comment was made to the effect that my problem pertains to Job Shop Scheduling and that it was more of a comp sci problem than a programming ...
0
votes
0answers
8 views
Job shop scheduling variant with non-sequential process plans
As the title says, I am looking for a variant of the job shop scheduling problem which allows for non-sequential process plans.
For example, I might have a job whose task-order constraints look like ...
0
votes
1answer
3k views
Operating Systems - SJN/Round Robin - turn around time + waiting time
2.(10 pts) a) You are given 4 processes in a batch system that all arrive at time 0 with the following CPU burst times:
P1 : 35, P2: 25, P3: 13, P4: 22. Assuming there is no context switch ...
0
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0answers
129 views
Why TurnAround Time is considered as Performance Metric for Scheduling Algorithms?
I know what is turn around time but i am confused why wating time is not considred as Performance Metric for Scheduling Algorithms Since it gives the time for which a Process will wait till it gets ...
0
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0answers
433 views
why p1 misses it first deadline? Rate monotonic scheduling
I understand that rate monotonic scheduling assigns a priority to a process based on the periodicity of the tasks it generates and the process with the shortest inter-task period has the highest ...
0
votes
1answer
2k views
Arrival Time vs Burst Time vs Priority Time? If Priority Time is the same, which process dispatch first?
The question is based on if we have the same Priority value when we are given:
Arrival Time = AT, Priority and Burst Time=BT.
1.Say if we a table with AT, Priority and BT. To dispatch a process it is ...
-1
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0answers
36 views
Process scheduling arrival time FIFO
I am a CS student and for the exam(Operating System) I have a problem like this: I receive a list of 9 process, and for every process I receive execution time(burst) and waiting time(for FIFO/FCFS ...
-2
votes
1answer
83 views
OS process management
Assume a process execution interrupted at the middle and CPU started executing a different process.How does the OS handle this situation?
