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

If a process is blocked, There is a process bloacked by a semaphore and no ...

There is a process bloacked by a semaphore and no other process in the ready queue, can the blocked process get back to the ready queue without the semsignal() function?

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

Define what is dispatcher, Define what is Dispatcher In the Worker Mode...

Define what is Dispatcher In the Worker Model, it is the task of the Dispatcher to spawn a thread for every client-to-server connection. The Dispatcher acts as the go-between o

Difference between internal and external fragmentation, Explain the differe...

Explain the difference between internal and external fragmentation. Internal Fragmentation is the area in a region or a page that is not used by the job occupying that region o

List three ways of allocating storage, List three ways of allocating storag...

List three ways of allocating storage, and give advantages of each. a. Contiguous allocation. Fastest, if no changes are to be made. Also simplest for random access files. b

Explain system-wide open-file and per-process open-file, Explain system-wid...

Explain system-wide open-file and per-process open-file The system-wide open-file table have a copy of the FCB of each open file, as well as other information. The per-pr

Explain the various methods for handling deadlocks, Explain the various met...

Explain the various methods for handling deadlocks.      A set of processes is deadlocked if every process in the set is waiting for an event that only a process in the

Fundamental of operating system, An operating system provides the environme...

An operating system provides the environment within that programs are executed. Internally operating systems differ greatly in their makeup because they are organized along many di

Address operator and pointers, We are use to using variables within C witho...

We are use to using variables within C without thinking about where they are stored. Most variables are dynamic i.e. can change, therefore they are stored in Ram, unlike a program

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