Please answer accurately and claarly.... #1. Analyze the performance of three sc

Question

Please answer accurately and claarly....

#1.

Analyze the performance of three scheduling mechanisms: Exponential Averaging, MLFQ, and true ShortestBurstFirst.   Calculate the Average Completion Time AND count the number of context switches.   The workload consists of the following:

P1: 10(3,2,4); P2: 4(2,6); P3: 16(2,4,5,6).      I/O between bursts for 4 time quantums.   Exp Ave default =2, alpha=0.6

MLFQ: 3 queues of 2,3 and 4 quantums for the queues. Processes are executed in FIFO order within each queue.

Executing (initial pred=2, alpha =0.6)

Time

0

Exec

Ready

1,2,3

P1

2

P2

2

P3

2

I/O:4

Ave completion time =       Context switches =

MLFQ: Executing in Queues

Time

0

Q1:1

Q2:2

Q3:4

MLFQ: In Queues

Q1

1,2,3

Q2

Q3

IO:4

Ave Completion Time =        Context switches =

True SJF:

Time

0

Executing

ReadyQ

1,2,3

I/O:4

Completion time ave =                                                            .   Context switches =     .  

Executing (initial pred=2, alpha =0.6)

Time

0

Exec

Ready

1,2,3

P1

2

P2

2

P3

2

I/O:4

Explanation / Answer

Enforcement of fairness in allocating resources to processes Enforcement of priorities Make best use of available system resources Give preference to processes holding key resources. Give preference to processes exhibiting good behavior. Degrade gracefully under heavy loads. 6 Issues to consider in scheduling I/O boundedness short burst of CPU before blocking for I/O CPU boundedness extensive use of CPU before blocking for I/O Urgency and Priorities Frequency of preemption Process execution time Time sharing amount of execution time process has already received. 7 Levels of Scheduling High Level Scheduling or Job Scheduling Selects jobs allowed to compete for CPU and other system resources. Intermediate Level Scheduling or Medium Term Scheduling Selects which jobs to temporarily suspend/resume to smooth fluctuations in system load. Low Level (CPU) Scheduling or Dispatching Selects the ready process that will be assigned the CPU. Ready Queue contains PCBs of processes.

Related Questions

Navigate

• Browse (All)
• Browse P
• Subjects

---

---

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.