COS3721
ASSIGNMENT 2 2026
UNIQUE NO.
DUE DATE: 1 JULY 2026
, Operating Systems and Architecture - COS3721
Assignment 2 2026
Question 1
a. Explain how each approach schedules CPU-intensive and short interactive
tasks. (4)
Per-core run queues:
Each processor core has its own queue of ready processes.
CPU-intensive tasks are usually assigned to a specific core and continue running
on that core, benefiting from cache locality.
Short interactive tasks are placed in the queue of a particular core and must wait
behind other tasks in that queue unless load balancing moves them elsewhere.
Shared run queue:
All ready processes are placed in one global queue shared by all cores.
Any idle core can select the next task from the queue.
Short interactive tasks can be scheduled quickly by any available core, while
CPU-intensive tasks are distributed across cores from the same queue.
b. List at least two advantages and two disadvantages for each scheduling
approach. (6)
Scheduling
Advantages Disadvantages
Approach
1. Better cache performance
1. Load imbalance may occur if
because tasks often stay on the
Per-core run some cores have many tasks
same core.
queues while others are idle.
2. Reduced contention since each
2. Requires additional load-
core manages its own queue.
ASSIGNMENT 2 2026
UNIQUE NO.
DUE DATE: 1 JULY 2026
, Operating Systems and Architecture - COS3721
Assignment 2 2026
Question 1
a. Explain how each approach schedules CPU-intensive and short interactive
tasks. (4)
Per-core run queues:
Each processor core has its own queue of ready processes.
CPU-intensive tasks are usually assigned to a specific core and continue running
on that core, benefiting from cache locality.
Short interactive tasks are placed in the queue of a particular core and must wait
behind other tasks in that queue unless load balancing moves them elsewhere.
Shared run queue:
All ready processes are placed in one global queue shared by all cores.
Any idle core can select the next task from the queue.
Short interactive tasks can be scheduled quickly by any available core, while
CPU-intensive tasks are distributed across cores from the same queue.
b. List at least two advantages and two disadvantages for each scheduling
approach. (6)
Scheduling
Advantages Disadvantages
Approach
1. Better cache performance
1. Load imbalance may occur if
because tasks often stay on the
Per-core run some cores have many tasks
same core.
queues while others are idle.
2. Reduced contention since each
2. Requires additional load-
core manages its own queue.
