SSTF scheduling is essentially a form of shortest-job-first (SJF) scheduling;
and like SJF scheduling, it may cause starvation of some requests. Remember
that requests may arrive at any time. Suppose that we have two requests in
the queue, for cylinders 14 and 186, and while servicing the request from 14,
a new request near 14 arrives. This new request will be serviced next, making
the request at 186 wait. While this request is being serviced, another request
close to 14 arrive. In theory, a stream of requests near one
another could arrive, causing the request for cylinder 186 to wait indefinitely
SSTF scheduling is essentially a form of shortest-job-first (SJF) scheduling;and like SJF scheduling, it may cause starvation of some requests. Rememberthat requests may arrive at any time. Suppose that we have two requests inthe queue, for cylinders 14 and 186, and while servicing the request from 14,a new request near 14 arrives. This new request will be serviced next, makingthe request at 186 wait. While this request is being serviced, another requestclose to 14 arrive. In theory, a stream of requests near oneanother could arrive, causing the request for cylinder 186 to wait indefinitely
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