Exam 3: Memory Management: Virtual Memory

In the PMT, the ____ bit for all pages in memory is 1.

A job's working set is the set of pages residing in memory that can be accessed indirectly.

The key to the successful implementation of demand paging is the use of a direct access memory device that can work directly with the CPU.

Cache memory is a small high-speed memory unit that a processor can access less rapidly than main memory.

One of the most important innovations of demand paging was that it made ____ feasible.

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

Every time an instruction is executed, or a data value is used, the operating system (or the hardware) must translate the job space address, which is relative, into its physical address, which is absolute.

Each page of a job is actually stored in a page frame that can be located anywhere in available main memory.

Within the Memory Manager the Segment Link Table lists details about each segment (one for each job).

There are ____ entries per page in the PMT.

In general, when a job is allocated to the CPU its Page Map Table is loaded into main memory while the Segment Map Tables are loaded only as needed.

Paged memory allocation usually results in internal fragmentation, but never external fragmentation.

Consider the following four cases. The LRU policy,____, will be lease likely to swap. Modified Referenced Meaning Case 1 0 0 Not modified AND not referenced Case 2 0 1 Not modified BUT was referenced Case 3 1 0 Was modified BUT not referenced Case 4 1 1 Was modified AND was referenced

____ gives users the appearance that their programs are being completely loaded in main memory during their entire processing time.

Assume that four page frames are available and are numbered 1-4. Pages A-D have been loaded into page frames 1-4 in order. The program has accessed the pages in the following order: B, D, A, C. Assume that page E is requested. The ____ page frame will be loaded when the LRU algorithm is used.

Demand paging was the first widely used scheme that removed the restriction of having the entire job in memory from the beginning to the end of its processing.

In demand paging when a job requires a certain page to be loaded and there is no empty page frame,____ .

The address of the beginning of a page frame is found by multiplying the page frame number by the number of frames.

The following phrase____,means that during any phase of its execution, the program references only a small fraction of its pages.

The first-in first-out (FIFO) page replacement policy will remove the pages that have been in memory the shortest.