08 09 2022 E TS

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Advanced Operating Systems - Part A, September 8th, 2022 Exercises and solutions Exam finalization Question 1.1 This is part A of the AOS’s exam and today you are finalising your entire grade. You must express now how you have finalised part B. The answer is mandatory for the entire exam. Exercise 2 — Open and closed questions (Points 15) Question 2.1 (Points 5) Describe the available scheduling classes in the Linux operating system Question 2.2 (Points 5) Describe the four conditions for a deadlock and how they can be mitigated Question 2.3 (Points 3) Describe how a log-structured FTL can minimize write amplification in SSD drives Question 2.4 (Points 2) Describe the main methods used by Linux for device discovery Exercise 3 — Scheduling (Points 7) Question 3.1 (Points 7) Consider the following definition: Work-conserving policy : does not allow a CPU to be idle if there are tasks in the ready queue. If both CPUs are available, the scheduler prefers to allocate tasks on CPU 1 rather than CPU 2. No task migrations are allowed. Now, given task set in the following table, answer to the following questions • draw the Gantt diagram of the schedule obtained by applying a non-preemptive First-In First-Out (FIFO) work-conserving policy on a dual-core with a single global queue. • fill the last column in the table according to the above scheduling algorithm • in multi-processor scheduling, what are the advantages and disadvantages of a single global queue com- pared to multiple per-processor queues? Task Arrival time ( Ai) Completion time ( Ci) Turnaround time ( Zi) T1 0 3 T2 1 3 T3 2 5 T4 3 3 T5 4 1 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 1 1 1 1 1 1 1 1 1 2 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 1 1 1 1 1 1 1 1 1 2 CPU1 CPU2 Solution 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8…