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

Define spooling, Define spooling. A spool is a buffer that holds output...

Define spooling. A spool is a buffer that holds output for a device, like printer, that cannot accept interleaved data streams. When a request finishes printing, the spooling s

What are the operations that can be performed on a directory, What are the ...

What are the operations that can be performed on a directory? The operations that can be performed on a directory are Search for a file Create a file Delete a

Explain segmentation and paging, Why are segmentation and paging sometimes ...

Why are segmentation and paging sometimes combined into one scheme? Segmentation and paging are often combined in order to improve upon each other. Segmented paging is helpful

How does dma raise system concurrency, Q. How does DMA raise system concurr...

Q. How does DMA raise system concurrency? How does it make difficult hardware design? Answer: DMA increases system concurrency by allowing the CPU to perform tasks while the

Components of the r/e system, What components of the R/e system initiate th...

What components of the R/e system initiate the start of background jobs at the specified time? The batch scheduler initiates the begin of background job.  The dispatcher then s

Fork join, fork and join syntax in java

fork and join syntax in java

Define memory management, Define memory management In multiprogramming ...

Define memory management In multiprogramming system the user part of memory should be further subdivided to accommodate multiple processes. The task of subdivision is carried o

Benefits of dynamic linkage of libraries, Q. What are three benefits of dyn...

Q. What are three benefits of dynamic (shared) linkage of libraries compared to static linkage? What are two situations where static linkage is preferable? Answer: The

Bind a real-time thread to an lwp, Q. Suppose an operating system maps user...

Q. Suppose an operating system maps user-level threads to the kernel utilizing the many-to-many model where the mapping is done through the use of LWPs. In addition the system allo

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

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