25-Comp-A5 Operating Systems
Worked solutions to 11 past sittings (2013–2019), 77 questions. Pick a sitting, or start from a topic below.
- December 2019
- May 2018
- December 2017
- May 2017
- December 2015
- May 2015
- December 2014
- May 2014
- December 2013
- May 2013
- Undated paper
Topics across the sittings
Topics that come up in more than one sitting, taken from the headings of our worked solutions. A topic counts once per sitting.
- CPU Scheduling (8 sittings): May 2018 Q2 · December 2017 Q1 · December 2015 Q1 · December 2014 Q1 · May 2014 Q1 · December 2013 Q1 · May 2013 Q1 · Undated paper Q1
- Protection (8 sittings): May 2018 Q7 · December 2017 Q7 · May 2017 Q7 · December 2015 Q7 · December 2014 Q3 · May 2014 Q6 · December 2013 Q7 · Undated paper Q7
- Deadlocks (7 sittings): May 2018 Q4 · May 2017 Q5 · May 2015 Q3 · December 2014 Q4 · May 2014 Q2 · May 2013 Q7 · Undated paper Q3
- Disk Scheduling (7 sittings): May 2018 Q4 · December 2017 Q4 · May 2017 Q6 · December 2015 Q7 · December 2014 Q3 · May 2014 Q6 · May 2013 Q6
- Fragmentation (6 sittings): December 2017 Q2 · May 2017 Q6 · May 2015 Q7 · May 2014 Q3 · December 2013 Q4 · May 2013 Q4
- Starvation (5 sittings): December 2017 Q1 · May 2015 Q3 · December 2014 Q4 · May 2014 Q7 · Undated paper Q3
- Demand Paging (4 sittings): May 2018 Q5 · May 2017 Q2 · December 2015 Q2 · Undated paper Q2
- Effective Access Time (4 sittings): December 2017 Q2 · December 2015 Q2 · December 2014 Q6 · Undated paper Q3
- Address Binding (3 sittings): May 2017 Q7 · May 2015 Q5 · Undated paper Q7
- Address Translation (3 sittings): May 2018 Q7 · May 2017 Q2 · Undated paper Q2
- Free-Space Management (3 sittings): May 2017 Q4 · May 2014 Q4 · Undated paper Q4
- Monitors (3 sittings): May 2018 Q1 · May 2015 Q3 · December 2014 Q5
- Page Replacement (3 sittings): December 2017 Q3 · December 2015 Q3 · December 2013 Q7
- Real-Time Systems (3 sittings): May 2018 Q1 · May 2015 Q5 · May 2014 Q1
- Access Control (2 sittings): May 2018 Q6 · December 2013 Q6
Questions by sitting
December 2019
May 2018
- Question 1: Critical Section, Monitors, Real-Time Systems
- Question 2: CPU Scheduling
- Question 3: Locality of Reference, Thrashing, and Working Sets
- Question 4: Deadlocks and Disk Scheduling
- Question 5: Demand Paging and Page Reference Strings
- Question 6: File Systems — Access Control and Allocation Performance
- Question 7: Protection, Address Translation, and Scheduling Trade-offs
December 2017
- Question 1: CPU Scheduling and Starvation
- Question 2: Multiprogramming, Effective Access Time, Fragmentation
- Question 3: Page Replacement and Memory Allocation
- Question 4: Deadlock Feasibility and Disk Scheduling
- Question 5: File Allocation and the Critical-Section Problem
- Question 6: Deadlock States, Prefetching, and Multithreading
- Question 7: File Systems and Protection
May 2017
- Question 1: Dynamic-Priority Scheduling and SJF
- Question 2: Address Translation and Demand Paging
- Question 3: Critical Section Problem
- Question 4: File Allocation and Free-Space Management
- Question 5: Deadlocks
- Question 6: Disk Scheduling, Thrashing, Fragmentation
- Question 7: Priority Inversion, Protection, Multiprocessor Scheduling, Address Binding
December 2015
- Question 1: CPU Scheduling
- Question 2: Demand Paging and Effective Access Time
- Question 3: Paging and Page Replacement
- Question 4: Linked Allocation and Scheduler Design
- Question 5: Reliability and Deadlock Analysis
- Question 6: Monitor Design for Bounded Concurrent Access
- Question 7: Real-Time Classification, Disk Scheduling, Protection
May 2015
- Question 1: Generalized (Quadratic) Priority-Scheduling Formula
- Question 2: Memory Increase vs. CPU Utilization; Best-Fit and First-Fit Allocation
- Question 3: Monitors, the Readers-Writers Problem, and Deadlock vs. Starvation
- Question 4: Necessary Conditions for Deadlock; PID-Ordered Resource Waiting; Safe vs. Unsafe States
- Question 5: Real-Time Systems; Disk-Head Scheduling; Address Binding
- Question 6: Variant Round-Robin Scheduling; Page-Reference LRU Trace
- Question 7: Contiguous File Block Operations; Fragmentation; Disk Reliability; File Protection
December 2014
- Question 1: CPU Scheduling and Real-Time Priority
- Question 2: Paging and Virtual Memory
- Question 3: Protection, Security, and Disk Scheduling
- Question 4: Deadlocks, Starvation, and File Sharing
- Question 5: Critical Section Analysis, Monitors, and Semaphores
- Question 6: Virtual Memory, Effective Access Time, and Locality
- Question 7: Free Space Management, Resource Optimality, Shared Files, and Real-Time Classification
May 2014
- Question 1: CPU Scheduling and Real-Time Systems
- Question 2: Deadlocks — Disk Sharing, Prevention, and a Resource-Bound Proof
- Question 3: Working Sets, FIFO Paging, and Fragmentation
- Question 4: Disk Block Allocation and Free-Space Management
- Question 5: Monitor for a Priority-Scheduled Shared Plotter
- Question 6: Protection, Disk Scheduling, and Disk Redundancy
- Question 7: Deadlock Handling, Starvation, and Directory Structures
December 2013
- Question 1: CPU Scheduling and Multiprocessor Difficulty
- Question 2: Flawed Critical-Section Solution, Requirements, and Semaphores
- Question 3: Deadlock Possibility with a Single Resource Type
- Question 4: Fragmentation and Memory Allocation Policies
- Question 5: Multi-Resource Systems and Disk-Head Scheduling
- Question 6: File Sharing via Links and Access Control
- Question 7: Real-Time Scheduling, System States, Page Replacement, and Protection
May 2013
- Question 1: CPU Scheduling
- Question 2: Monitor for Bounded Concurrent Access
- Question 3: Disk Allocation Methods
- Question 4: Virtual Memory and Fragmentation
- Question 5: Priority Scheduling Parameters and Optimal Page Replacement
- Question 6: File Protection and Disk Scheduling
- Question 7: Disk Space Management, Multiprocessor Scheduling, and Deadlocks
Undated paper
- Question 1: CPU Scheduling — Generic Priority Formula & SRTF
- Question 2: Address Translation & Demand Paging
- Question 3: Scheduler Design Defects, Deadlock vs. Starvation, Effective Access Time
- Question 4: Linked-List File Allocation, Multi-Level Directories, Free-Space Management
- Question 5: Deadlock Conditions, Read-Only Files, Resource-Bound Safety
- Question 6: Disk-Scheduling Algorithms; Processes vs. Threads; Optimal CPU Scheduling
- Question 7: Priority Inversion, Security vs. Protection, Disk Fragmentation, FAT, Address Binding