Exam 3: Memory Management: Virtual Memory Systems

In a demand paging scheme,the first-in first-out (FIFO)page replacement policy chooses the page least recently accessed to be swapped out.

Thrashing is a problem that occurs when there are a large number of jobs and many free pages so that pages are being moved around too much.

The segmented/demand paged memory allocation scheme is a combination of segmentation and demand paging,and it offers the logical benefits of segmentation,as well as the physical benefits of paging.

Cache memory is divided into blocks of equal size called ____.

In demand paging schemes,the ____ in a Page Map Table indicates whether the page is currently in memory.

In a paged memory allocation scheme,the ____ contains two values for each active job: the size of the job and the memory location where its Page Map Table is stored.

To access a location in memory when using segmented memory management,the address is composed of two entries: ____.

In a paged memory allocation scheme,to find the actual position of an instruction in memory,first the page number and displacement are determined.Then the operating system refers to the job's PMT to correlate the page with its page frame.

When using a FIFO scheme,adding more memory always results in better performance.

With segmented memory allocation,each job is divided into several ____ of different sizes,one for each module that contains pieces that perform related functions.

The ____ page replacement policy is based on the theory that the best page to remove is the one that has been in memory the longest.

The primary advantage of storing programs in noncontiguous page frames (in a paged memory allocation scheme)is that main memory is used more efficiently because an empty page frame can be used by any page of any job.

The optimal selection of cache size and replacement algorithm can result in 80 to 90 percent of all requests being in the cache.

A job's working set is the collection of pages that must be loaded from secondary storage.

Virtual memory can be implemented with both paging and segmentation.

Paged memory allocation offers the advantage that it doesn't require the entire job to be stored in memory during its execution.

In a paged memory allocation scheme,a page size that is too small will generate ____.

The key to the successful implementation of demand paging is the use of a high-speed CPU.

The Job Table (JT)contains two values for each active job: the size of the job and the memory location where its Page Map Table is stored.

The purpose of cache memory is to keep handy the most recently accessed data and instructions so that the CPU can access them repeatedly without wasting time.This purpose is similar to that of the ____ of a Web browser.