Expect to come across this popular operating system interview questions and answers. Starvation: Indefinite blocking or starvation is a phenomenon associated with Priority scheduling algorithms in which a process ready for the CPU (resources) can wait indefinitely due to low priority. A steady stream of higher-priority processes in a heavily loaded computer system can prevent a low-priority process from ever receiving the CPU. According to rumors, Priority Scheduling was used in IBM 7094 at MIT in 1967, and they discovered a low-priority process that had not been submitted until 1973.  Aging: Aging is a method of gradually raising the priority of processes that have been waiting in the system for a long time. For example, if the priority range is 127 (low) to 0, we could raise the priority of a waiting process by 1 every 15 minutes. Even if a process had a starting priority of 127, it would take no more than 32 hours for the priority 127 processes to age to a priority-0 process.