Question

Discuss the potential advantages and disadvantages of “Fair-Share Scheduling”.

Answer 1

Fair-share sheduling is an algorithm which provides algorithm for computer operating systems that dynamically distributes the time quanta equally to its users.

An example is that, if four users (A,B,C,D) are concurrently executing one process each, the scheduler will logically divide the available CPU cycles such that each user gets 25% of the whole.

Advantages -

• Fair-share sheduler is effective in allocating resources i.e ensure fainess in resource allocation.

• It ensures that all processes will get resources that they want at some reasonable amount of time.

• Fair-share sheduler increases response time for each process.

• It also ensures that all resources of the machine are well utilized.

• Fair-share sheduler also increases the performance of system during peak load time.

Disadvantages :-

• A mix of processes in the fair-share sheduling along with time shareing(TS), Interactive (IA), and Fixed priority(FX) sheduling classes could result in unexpected scheduling behavior.

• The Solaris system offers a real-time (RT) scheduler to users with superuser privileges.

Fair-share scheduling class does not have any control over processes that run in the RT class.

• Fair-share sheduler algorithm does not take an account of long term history of user's activity.

So, Fair share sheduling algorithm is a best way to provide equal time slot to each task in operation.

Thumps up!