Answer to Question #271488 in Electrical Engineering for Saurav kumar

Question

An extra address space is accocated by the operating 

system to easily run applications . Elaborate on this 

with proper method and strategy of page swapping.[10 marks]

Answer 1

Explnation

• If the PFF is exceptionally low, free some of this processes frames (e.g., limit victim selection to this process for a while).
• If the PFF is too high, allocate more frames to this process using one of the below

1. Raise its number of frames if using a local policy; or
2. Bar its frames from eviction (for a while) and use a global policy.

Limit register holds the size of a process.

Explanation

Base register and limit register for memory protection. The base register hops the smallest legal physical memory address; the limit register contains the size of the range.

A limit register specifies the size of the physical memory range for a process. To get this range, values of limit register and base register can be added. ( i.e., if base range is 2000, and Limit Register is 6000, legal range is 8000 )

The most preferred method of swapping a process is to copy an entire file to swap space at process startup and then perform demand paging from the swap space.