#preemption closed

Question

If a process comes from block state to ready state then what can be said about preemption ?

Answer 1

You can't say anything about preemption with just that. As far as I know, a process will block itself when there is I/O to be performed, hence transitioning from Ready state to Block state and back to Ready state once the I/O is done (assuming it's synchronous I/O).

You can be sure about preemption only if a process transitions from Running state to Ready state.

Answer 2

I think we can say that there is preemption.

Because if there were no preemption, then when a running process goes to block state, we don't move any other process in CPU. So, when it should come out of block state, it should go straight to CPU, instead of going to ready queue.

Comments

No, we can't say it as preemption because process transition from ready to run state and vice versa is employing preemption.