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The PRIMARY DISADVANTAGE of FIFO scheduling is
Ahigh context-switch overhead
Bit requires knowledge of future job arrivals
Cstarvation of high-priority jobs
Dthe CONVOY EFFECT, where short jobs wait behind a long one
Answer & Solution
Correct answer: D. the CONVOY EFFECT, where short jobs wait behind a long one
1. OSTEP §7.3 names the CONVOY EFFECT: if a long-running job (cargo ship 'A') is at the head of the queue, all shorter jobs behind it must wait for the entire long run to finish.
2. Result: average turnaround time is dominated by the long job's run time, regardless of how short other jobs are.
3. Example: jobs with run times $100, 10, 10$ have average turnaround $110$ under FIFO — much worse than SJF's $50$.
4. Option A is wrong — FIFO has LOW context-switch overhead (no preemption). Options C, D don't apply to FIFO.
_Source: OSTEP Ch 7, §7.3 (FIFO — convoy effect), p. 3._
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