What is no preemption in deadlock?
Previously granted resources may not be taken away forcefully from the processes
holding them. For example, process P1 holds the resource R1 and waits for the
resource R2, which is locked by the process P2 in exclusive mode. The concept of
no-preemption indicates that operating system cannot take away forcefully the
resource R2 (for process P1) from the process P2.