PriorityScheduling leads to the risk of starvation: a process is ready, butnever

Question

1. PriorityScheduling leads to the risk of starvation: a process is ready, butnever is given the processor. Some preemptive priority schedulerstherefore reserve a fraction of the processor cycles for use onlower priority queues, some others implement priority aging wherebythe priority of a process increases the longer it has been waiting.Discuss the relative advantages and disadvantages of theseschedulers versus a preemptive priority scheduler where prioritiesare fixed, and the analysis of response time of a process need onlyconsider processes at the same and higher priorities (assumingpriority inversion is ignored), and where also a process canguarantee that no higher priority process can be pending when thisprocess is executing (i.e. higher priority process execution isatomic with respect to this process.).

Explanation / Answer

Advantages of using preemptive priority schedulers (with special reservation for low priority process or increase in priority due to aging): 1) Low priority process need not have to wait indefinitely long if high priority processes keeps on coming into the system. This is because either priority of the process increase due to aging or it will be executed in the reserved fraction of the processor time for low priority processes. 2) Response time for low priority processes will be better than that of preemptive priority schedulers. Disadvantages: 1) High priority processes may suffer a little bit because of reserved time of processor for the execution of low priority processes. 2) Response time for high priority processes might be a little high in these special preemptive priority schedulers.

Related Questions

Navigate

• Browse (All)
• Browse P
• Subjects

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.