Exam 8: Virtual Memory

The page currently stored in a frame may still be replaced even when the page is locked.

To overcome the problem of doubling the memory access time, most virtual memory schemes make use of a special high-speed cache for page table entries called a __________ .

The size of virtual storage is limited by the addressing scheme of the computer system and by the amount of __________ available.

Segmentation is not visible to the programmer.

_________ is where modified process pages can be written out at the time of replacement, or a precleaning policy can be used, which clusters the output activity by writing out a number of pages at once.

The addresses a program may use to reference memory are distinguished from the addresses the memory system uses to identify physical storage sites.

The PFF policy evaluates the working set of a process at sampling instances based on elapsed virtual time.

__________ is the range of memory addresses available to a process.

A __________ policy allows the number of page frames allocated to a process to be varied over the lifetime of the process.

When the system spends most of its time swapping pieces rather than executing instructions it leads to a condition known as _________ .

One way to counter the potential performance problems of a variable-allocation global scope policy is to use page buffering.

The size of virtual storage is limited by the actual number of main storage locations.

The smaller the page size, the greater the amount of internal fragmentation.

Virtual memory allows for very effective multiprogramming and relieves the user of the unnecessarily tight constraints of main memory.

A _________ chooses only among the resident pages of the process that generated the page fault in selecting a page to replace.

With _________ pages other than the one demanded by a page fault are brought in.

The placement policy determines where in real memory a process piece is to reside.

The __________ provides a virtual memory capability that allocates page frames in main memory to processes and also allocates page frames to disk block buffers.

UNIX is intended to be machine independent; therefore its memory management scheme will vary from one system to the next.

The technique where the processor is equipped with hardware that allows it to interrogate simultaneously a number of TLB entries to determine if there is a match on page number is referred to as __________ .