Skip to main content

Loading the code workspace…

LC

Implement Multi-Level Feedback Queue Scheduler

hard7/9

Implement wait() and waitpid() for Child Process Reaping Implement CPU Affinity: Pin Processes to Specific Cores

Language

Compiler

2.0s Limit 256MB

Submit and pass all tests to enable saving to GitHub.

Implementation

Implement Multi-Level Feedback Queue scheduler.

Requirements:

Create multiple priority queues (at least 4 levels)
Different time quantum per queue (10ms, 20ms, 40ms, FCFS)
New processes start in Queue 0 (highest priority)
Implement time quantum measurement
Demote processes that use full time slice
Keep processes that yield early in same queue
Always select from highest non-empty queue
Round-robin within same queue
Add periodic priority boost (every N seconds, raise all to Queue 0)
Track and print queue movements
Demonstrate adaptive behavior with I/O-bound and CPU-bound processes

Test scenarios:

I/O-bound process stays in high queues
CPU-bound process sinks to low queues
Interactive process remains responsive
Starvation prevention with priority boost

Why This Matters

MLFQ is the scheduling family that ran production Unix and Windows NT for decades before Linux replaced it with CFS in 2007 (and CFS itself was replaced by EEVDF in kernel 6.6), precisely because naive MLFQ starves CPU-bound batch jobs without a periodic priority boost. The I/O-bound-versus-CPU-bound classification you build here is the same heuristic real schedulers use to decide whether a process is 'interactive' and deserves lower latency.

Hints

0 / 3 revealed

Validation Suite

main.c

Workspace 1.0

← Implement wait() and waitpid() for Child Process ReapingImplement CPU Affinity: Pin Processes to Specific Cores →