Explain a computing environment, Operating System

Assignment Help:

Q. Polling for an I/O completion is able to waste a large number of CPU cycles if the processor iterates a busy-waiting loop several times before the I/O completes. However if the I/O device is ready for service polling can be much more proficient than is catching and dispatching an interrupt. Explain a hybrid strategy that combines sleeping, polling, and interrupts for I/O device service. For every of these three strategies (pure polling, pure interrupts, hybrid) explain a computing environment in which that strategy is more efficient than is either of the others.

Answer: A hybrid approach could switch among polling and interrupts depending on the length of the I/O operation wait. For instance we could poll and loop N times and if the device is still busy at N+1 we could set an interrupt and sleep. This approach would evade long busy-waiting cycles. This process would be best for very long or very short busy times. It would be incompetent it the I/O completes at N+T (where T is a small number of cycles) because of the overhead of polling plus setting up and catching interrupts.

Pure polling is best with extremely short wait times. Interrupts are best with known long wait times.


Related Discussions:- Explain a computing environment

Define enforcing modularity for c, Define Enforcing Modularity for C Ad...

Define Enforcing Modularity for C Additionally, in C it is sometimes necessary to create modularity of design. C++  is very natural model for component based application design

Explain chaining to handle collision, Explain Chaining to Handle Collision ...

Explain Chaining to Handle Collision Chaining:  One easy scheme is to chain all collisions in lists attached to the suitable slot. This permits an unlimited number of collision

Question, A paper mill produces two grades of paper viz., X and Y. Because ...

A paper mill produces two grades of paper viz., X and Y. Because of raw material restrictions, it cannot produce more than 400 tons of grade X paper and 300 tons of grade Y paper i

Fibonacci sequence, #questionThe Fibonacci sequence is the series of number...

#questionThe Fibonacci sequence is the series of numbers 0,1,1,2,3,5,8,… Formally, it can be expressed as: fib0 = 0 fib1 = 1 fibn = fib n-1 + fib n-2 Write a C program u

What is a sequential file, What is a sequential file? A file that is re...

What is a sequential file? A file that is read one record or block or parameter at a time in order, based on a tape model of a file.

Example of producer consumer - semaphore, Now let's implement bounded produ...

Now let's implement bounded producer-consumer with semaphores, a Coke machine which is initially empty: semaphore sem_mutex = 1 // binary semaphore for mutual exclusion, 1==unlo

File management, five major activities on file management in operating syst...

five major activities on file management in operating system.? Explain it.?

Replacement algorithm for tlb, Consider the following C program where M, N,...

Consider the following C program where M, N, K are predefined constants. Assume int is 4 bytes. Suppose this program is run on a machine with 4KB page size and 32 TLB entries. Init

What is the basic function of assembler, Q. What is the basic function of A...

Q. What is the basic function of Assembler ? Input to an assembler is an assembly language program. Output is an object program and information which enables the loader to prep

What is co-operative process, What is co-operative process? A process i...

What is co-operative process? A process is co-operating if it can influence or be affected by the other processes implementing in the system. Any process that share data with o

Write Your Message!

Captcha
Free Assignment Quote

Assured A++ Grade

Get guaranteed satisfaction & time on delivery in every assignment order you paid with us! We ensure premium quality solution document along with free turntin report!

All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd