Difference Between Interrupt and Polling in OS

Operating SystemHardwareComputer Network

In this post, we will understand the difference between interrupt and polling in operating system −


  • It is a process with the help of which the CPU is notified of requiring attention.

  • It is considered as a hardware mechanism.

  • An interrupt handler services/works with the device.

  • Interrupt-request line indicates that the device needs to be serviced.

  • CPU is used only when a device requires servicing.

  • This, in turn, saves the CPU cycles.

  • An interrupt can occur at any point in time.

  • It becomes inefficient if devices frequently interrupt the CPU.


  • The process in which the CPU constantly checks the status of the device- to see if it needs the CPU's attention.

  • It is a protocol.

  • In this protocol, the CPU services the device.

  • The command-ready bit indicates that the device needs to be serviced.

  • The CPU needs to wait and check if a device needs to be serviced.

  • This wastes many of the CPU cycles.

  • CPU polls the devices at regular intervals of time.

  • This protocol becomes inefficient when the CPU rarely finds a device that is ready to be serviced.

Updated on 19-Apr-2021 06:28:37