Keeping track of free memory, Operating System

Assignment Help:

How do we keep track of where the free pieces of memory are? One idea is to maintain a set of linked-lists of free space; each linked-list will store free chunks of some given size (say, one list for chunks of 4 bytes, one for chunks of 8, 16, etc). This approach resembles the best-?t algorithm, since we can easily ?nd the list with chunks of memory that are the closest to what we need; the difference, of course, is that usually the linked lists store not objects of arbitrary size, but only powers of two. Also, we can never coalesce adjacent elements of the lists, or split elements, since then the very idea of segregating by size classes wouldn't make sense anymore. Another possible technique to keep track of free memory is called Big Bag of Pages (BiBOP). In this technique, a bunch of pages, usually segregated by size classes, is maintained such that there is a header on each page; on this header, among other things, we can ?nd a pointer to the next page of objects of that given size, and also a pointer to the ?rst free "slot" inside that page. Using the right optimizations we can make BiBOP ?nd and manage free slots of memory in O(1).


Related Discussions:- Keeping track of free memory

How many page faults take place in lru replacement, Q. Consider the subseq...

Q. Consider the subsequent page reference string: 1, 2, 3, 4, 2, 1, 5, 6, 2, 1, 2, 3, 7, 6, 3, 2, 1, 2, 3, 6. How many page faults would take place for the following replace

Vehicle tasks using semaphores, Gopher Gallery consists of a shopping mall ...

Gopher Gallery consists of a shopping mall and a cart ride that covers  the 150 acre habitat. There are m visitors and n single-person vehicles. Visitors  stroll around the mall at

Define dynamic linking, Define dynamic linking. Dynamic linking is same...

Define dynamic linking. Dynamic linking is same to dynamic loading, rather that loading being postponed unless execution time, linking is postponed. This feature is usually use

System protection, what is the need-to-know principle? why is it important ...

what is the need-to-know principle? why is it important for a protection system to adhere to this principle?

What is an operating system?, What is an operating system? An operating...

What is an operating system? An operating system is a program that acts as a mediator between a user and the computer hardware. The function of an operating system is to provid

Explain best fit algorithm, BEST FIT ALGORITHM Here scanning is for th...

BEST FIT ALGORITHM Here scanning is for the finest fit one. Signifies it searches the entire list for the best fit position. For the process therefore in that the process will

Mutual exclusion, With software algorithms for mutual exclusion, such as De...

With software algorithms for mutual exclusion, such as Dekker's algorithm, Peterson's algorithm, or Lamport's bakery algorithm, note that optimizing compilers and out-of-order exec

Define latency plus seek time, Define Latency plus seek time The total...

Define Latency plus seek time The total time to arrange a disk drive mechanism for a block of data to be read from is its Latency plus seeks time

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