[amp_mcq option1=”The LRU algorithm pages out pages that have been used recently” option2=”Thrashing is a natural consequence of virtual memory systems.” option3=”Seek analysis is used for analysing control-unit busy problems.” option4=”All of the above E. None of the above” correct=”option2″]
The correct answer is: B. Thrashing is a natural consequence of virtual memory systems.
- A. The LRU algorithm pages out pages that have been used recently is incorrect. The LRU algorithm pages out pages that have not been used recently.
- C. Seek analysis is used for analysing control-unit busy problems is incorrect. Seek analysis is used for analyzing disk access patterns.
- D. All of the above is incorrect. Only option B is true.
- E. None of the above is correct. Only option B is true.
Thrashing is a condition in which a virtual memory system spends most of its time paging, rather than executing user programs. This can happen when the amount of physical memory is too small to hold all of the pages that are currently in use. When this happens, the system has to page out pages that are currently in use in order to make room for pages that are needed. This can cause a vicious cycle, as the system spends more and more time paging, which causes it to page out even more pages, and so on.
There are a number of ways to prevent thrashing. One way is to increase the amount of physical memory. Another way is to use a more sophisticated virtual memory system that can better manage the use of physical memory.