22 07 2024 E TS

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Advanced Operating Systems - Part A, July 22nd, 2024 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 — General knowledge - Closed questions (Points 7) Question 2.1 (Points 7) Select the correct answer in the following quiz on general knowledge of operating systems. 0 correct answers will get you a D, up to two 2 correct answers will get you C, up to 4 you’ll get a B, above that you’ll get an A. Solution 1. Which of the following statements about spinlocks in the Linux kernel is correct? • □ Spinlocks can be substituted by atomic context and interrupt disabling on uniprocessors. 2. Which statement best describes how the free_area array is used in the context of linux kernel memory management? • □ It organizes free pages into lists according to their order (size). 3. In the Linux Completely Fair Scheduler (CFS), how does the ( pick_next_entity) function decide which task to run next? • □ Picks the entity with the smallest virtual runtime. 4. What role do Virtual Memory Areas (VMAs) play in Linux’ s handling of a process’ s memory? • □ VMAs determine valid addresses in the process’s memory. 5. In T otal Store Order (TSO) memory consistency used by x86 processors, what mechanism is employed to manage memory writes? • □ Writes are managed via a local write queue which temporarily holds the information before visibility. 6. What is the function of ( rcu_read_lock) and (rcu_read_unlock) in a task preemption context? • □ They inform the reclaimer and disable task preemption to prevent context switching. Exercise 3 — Open questions (Points 15) Question 3.1 (Points 5) Complete the code…