Approximating LRU
Explore how operating systems approximate Least Recently Used (LRU) page replacement by using hardware-supported use bits and the clock algorithm. Understand how this approach reduces computational overhead while improving memory management performance compared to naive methods.
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Use bits
As it turns out, the answer is yes: approximating LRU is more feasible from a computational-overhead standpoint, and indeed it is what many modern systems do. The idea requires some hardware support, in the form of a use bit (sometimes called the reference bit), the first of which was implemented in the first system with paging, the