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

Describe the concept of transaction atomicity, Q. Describe the concept of t...

Q. Describe the concept of transaction atomicity? Answer: A transaction is a sequence of read as well as writes operations upon some data followed by a commit operation. If the

What is the resident set and working set of a process, What is the resident...

What is the resident set and working set of a process? Resident set is that portion of the process image that is actually in real-memory at a certain instant. Working set is th

Designing issues in a network -transparency, Transparency Users mus...

Transparency Users must be able to access remote resources as though these resources were local. Transparency should as well promote user mobility. Users must be allowed

What are the various available scheme in ipc, Several schemes available are...

Several schemes available are as follows: Pipes : One-way communication process through which different process can interact. The problem is that the two processes could have

Explain the advantage of assembly language, Explain the Advantage of Assemb...

Explain the Advantage of Assembly Language The advantages of assembly language program is: a)    Reduced errors  b)    Faster translation times  c)    Changes could be ma

Define what an assembler is, Define what an assembler is An assembler i...

Define what an assembler is An assembler is machine dependant.

What is the use of fork and exec system calls, What is the use of fork and ...

What is the use of fork and exec system calls? Fork is a system call by which a latest process is created. Exec is also a system call, which is used after a fork by one of the

What is an i/o subsystem, What is an I/O subsystem? The control of devi...

What is an I/O subsystem? The control of devices connected to the computer is a main issue while designing operating systems. Because I/O deices differ widely in their function

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