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

File management, approaches to identify free memory area in a heap

approaches to identify free memory area in a heap

Dynamic scheduling, Dynamic scheduling : The number of thread in a program...

Dynamic scheduling : The number of thread in a program may be changed during the course of operation. Dynamic priority scheduling is a kind of scheduling algorithm in which the pr

Operation management, trace the historical evolution of the operations mana...

trace the historical evolution of the operations managent from themainly rural agricultural era of the artisans to the present day industrial revolution, high technoligical advance

Basic synchronization, (Add synchronization to your solutions to HW 3 to el...

(Add synchronization to your solutions to HW 3 to eliminate all of the race conditions.  You should not remove any of the sleep() commands that you used to produce the race conditi

Explain doscreatethread functions used in the os/2, Explain DosCreateThread...

Explain DosCreateThread Functions Used in the OS/2  DosCreateThread(&threadID,MyThreadFunction,arg,flags,stackSize) DosCreateThread creates a thread within the context of th

Explain the os/2 operating system, Explain the OS/2 Operating System Li...

Explain the OS/2 Operating System Like NetWare, OS/2 manage resources at three levels, as shown in Figure 4.5 Resources may be maintained at the session, process, and thread le

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

What is symmetric multiprocessing, Symmetric multiprocessing To get ma...

Symmetric multiprocessing To get maximum reliability and efficiency a mode of function called as symmetric multiprocessing is used. In essence, with SMP any program or threads

Difference between the vfork() and fork() system call, In the mean while th...

In the mean while the fork() system call the Kernel creates a copy of the parent process's address space and adds it to the child process. But the vfork() system call do no

What are the phases of background processing, What are the phases of backgr...

What are the phases of background processing? Phases are:- Job Scheduling. Job Processing. Job Overview.

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