1. What is the key principle of Least Laxity First (LLF) scheduling?
(A) Assign highest priority to task with shortest period
(B) Assign highest priority to task with earliest deadline
(C) Assign highest priority to task with longest execution time
(D) Assign highest priority to task with smallest laxity
2. Laxity of a task is defined as:
(A) Period minus execution time
(B) Deadline minus execution time minus current time
(C) Deadline minus current time
(D) Execution time minus response time
3. LLF scheduling is:
(A) Fixed-priority scheduling
(B) Dynamic-priority scheduling
(C) Round-robin scheduling
(D) Non-preemptive scheduling
4. Which task gets preempted in LLF?
(A) Task with smallest laxity
(B) Task with shortest period
(C) Task with longest execution time
(D) Task with largest laxity
5. LLF is optimal for:
(A) Independent periodic tasks
(B) Non-preemptive tasks
(C) Aperiodic batch tasks
(D) Dependent tasks with shared resources
6. Which is a disadvantage of LLF?
(A) Low CPU utilization
(B) Complexity and frequent preemption
(C) Non-deterministic output
(D) Fixed priority assignment
7. LLF scheduling recalculates priorities:
(A) Only at task release
(B) Periodically
(C) Only at task completion
(D) Continuously at each time unit
8. Which type of scheduling is LLF considered?
(A) Batch
(B) Non-preemptive
(C) Round-robin
(D) Preemptive
9. Laxity can also be called:
(A) Execution time
(B) Period
(C) Response time
(D) Slack time
10. LLF is particularly suitable for:
(A) Soft real-time tasks
(B) Background batch tasks
(C) General-purpose systems
(D) Hard real-time tasks with deadlines ≤ periods
11. In LLF, a task with zero laxity:
(A) Has lowest priority
(B) Has infinite time to execute
(C) Can be delayed
(D) Has already missed its deadline
12. Compared to RMS and EDF, LLF:
(A) Has lower overhead
(B) Is simpler to implement
(C) Uses fixed priorities
(D) Has higher preemption rate
13. LLF calculates laxity using:
(A) Relative deadline, current time, and remaining execution time
(B) Period only
(C) Arrival time only
(D) Execution time only
14. Which is TRUE about LLF?
(A) Task with least laxity always runs first
(B) Deadlines are ignored
(C) All tasks have equal priority
(D) Preemption is not allowed
15. LLF scheduling is dynamic because:
(A) Priorities are assigned at design time
(B) Priorities change with remaining laxity
(C) Tasks have fixed execution order
(D) All tasks have equal execution time
16. LLF can lead to:
(A) Low CPU utilization
(B) Task starvation
(C) Deterministic output
(D) High preemption overhead
17. Laxity becomes negative when:
(A) Task finishes early
(B) Task is preempted
(C) Task period is very long
(D) Task cannot meet its deadline
18. LLF is most suitable for:
(A) Aperiodic tasks only
(B) Tasks with arbitrary deadlines
(C) Non-preemptive tasks
(D) Single-task systems
19. Which statement about LLF is TRUE?
(A) Priorities are fixed
(B) Deadlines are ignored
(C) Only periodic tasks can use LLF
(D) Priorities change during execution based on laxity
20. LLF scheduling is mainly used in:
(A) General-purpose systems
(B) Soft background tasks
(C) Hard real-time systems requiring minimal deadline misses
(D) Batch systems