Q5. An OS running on a single CPU has the following two processes:

P₁ consists of a 70-ms CPU burst followed by an I/O request followed by a 30-ms CPU burst

P₂ consists of a 40-ms CPU burst followed by an I/O request followed by a 60-ms CPU burst

Draw a complete timing diagram showing how a time-sharing operating system will handle these processes under the following assumptions:

Both I/O requests go to the same device and each request takes 80 ms.

The I/O device will start processing a queued request as soon as the current request is done (no delay).

Whenever P₁ and P₂ are both ready, the scheduler will give the CPU to the process that did not get the last CPU time (fair alternation if both are ready). In the beginning, the CPU is given to P₁.

The time quantum is 50 ms

The kernel time (including initiation of I/O requests, scheduling and context switching) is 10 ms.

The OS starts each I/O request right at the beginning of the kernel time.

Ignore any delay or transition time that was ignored in class. (30 points)

Show both the CPU and the I/O device in your diagram and make sure that you align the CPU time with the I/O time.