OPERATING SYSTEM CONCEPTS 239
soon, the scheduling policy adopted for the system is assumed to be good—in
principle, the response time should be minimum.
iii) Turnaround time (TAT): e time interval from the instant the task is presented
to the system, to the instant that it exits after completion is defi ned as the ‘turn
around time’. is interval is likely to be quite eventful. Initially the task may have
to wait to get the CPU. Even after getting the service of the CPU, it may go to the
blocked state or back to the ready queue. Obviously then, the task may will not
get executed in ‘one go’. Parts of it may get executed until it reaches completion.
us the TAT is the sum total of the ‘execution’ periods and the ‘wait’ periods. For ...