Question

On a system using round robin scheduling let t represents the time needed to to perform a process switch, q represents the round robin time quantum and p represents the average time a process runs before blocks on input. Give a formula for CPU efficiency if t<q<p.

Answer 1

Answer on Question#39205 - Math - Other

On a system using round robin scheduling let $t$ represents the time needed to perform a process switch, $q$ represents the round robin time quantum and $p$ represents the average time a process runs before blocks on input. Give a formula for CPU efficiency if $t < q < p$.

Solution

Since $q < p$, each run of $p$ requires $p/q$ process switches, resulting in overhead of $\frac{tp}{q}$ and therefore, the efficiency is $\frac{p}{(p + tp/q)} = \frac{q}{q + t}$.

Answer: $\frac{q}{q + t}$