Single-level page tables, Operating System

Assignment Help:

As mentioned above, page tables, are lookup tables mapping a process' virtual pages to physical pages in RAM. How would one implement these page tables?

The most straightforward approach would simply have a single linear array of page-table entries (PTEs). Each PTE contains information about the page, such as its physical page number ("frame" number) as well as status bits, such as whether or not the page is valid, and other bits to be discussed later.

If we have a 32-bit architecture with 4k pages, then we have 2 pages, as discussed in the last lecture. If each PTE is 4 bytes, then each page table requires 4 Mbytes of memory. And remember that each process needs its own page table, and theremay be on the order of 100 processes running on a typical personal computer. This would require on the order of 400 Mbytes of RAM just to hold the page tables on a typical desktop!

Furthermore, many programs have a very sparse virtual address space. The vast majority of their PTEs would simply be marked  invalid.Clearly, we need a better solution than single-level page tables.


Related Discussions:- Single-level page tables

Recognition of essential syntactic constructs by reductions, Recognition of...

Recognition of essential syntactic constructs by reductions, this task is carried out by Recognition of essential syntactic constructs by reductions, this task is carried out

How many disks can be used effectively by one fast wide bus, Q. More than ...

Q. More than one disk drive is able to be attached to a SCSI bus. Especially a fast wide SCSI-II bus can be connected to at most 15 disk drives. Remember that this bus has a bandw

Is the internet a lan or else a wan, Q. Is the Internet a LAN or else a WAN...

Q. Is the Internet a LAN or else a WAN? Answer: The Internet is a WAN as the a variety of computers are located at geographically different places and are connected by long-dis

Explain relative file organization, Relative file organization A rela...

Relative file organization A relative file is an array of fixed-length slots and the records can be inserted in the first free slot found from the beginning of the file and

Several cpu-scheduling algorithms, Q. Several CPU-scheduling algorithms are...

Q. Several CPU-scheduling algorithms are parameterized for instance the RR algorithm requires a parameter to indicate the time slice. Multilevel response queues require parameters

Explain the beginthread function used in the netware, Explain the BeginThre...

Explain the BeginThread Function used in the NetWare example code BeginThread(MyThread Function, stack,size, arg) BeginThread creates a thread and places it on the NetWar

Explain the features that bash shell provides, LINUX OPERATING SYSTEM 1...

LINUX OPERATING SYSTEM 1. Write a brief explanation about the Linux distribution. 2. Explain the features that Bash shell provides? 3. Who is responsible for managing use

Linear Programing, . A paper mill produces two grades of paper viz., X and ...

. 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

What are the major differences between operating systems, Q. What are the m...

Q. What are the major differences between operating systems for mainframe computers and personal computers? Answer: In general operating systems for batch systems have simpler

Define implementation of segmentation with an example, IMPLEMENTATION OF SE...

IMPLEMENTATION OF SEGMENTATION WITH AN EXAMPLE Segmentation is a memory-management scheme that represents the user view of memory. A logical address space is the collection of

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