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| Page Replacement NRU |
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| (Not Recently Used) |
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| | Periodically
(i.e., on a clock interrupt) |
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| | Clear
R bit from all PTEs |
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| | When
needed, rank order pages as follows |
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| 1. | R = 0,
M = 0 |
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| 2. | R = 0,
M = 1 |
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| 3. | R = 1,
M = 0 |
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| 4. | R = 1,
M = 1 |
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| | Evict
a page at random from lowest non-empty |
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| class
(write out if M = 1) |
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| | Characteristics |
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| | Easy
to understand and implement |
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| | Not
optimal, but adequate in some cases |
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