- At page fault, system inspects pages
- Categories of pages based on the current values of their R and M bits:
- Class 0: not referenced, not modified.
- Class 1: not referenced, modified.
- Class 2: referenced, not modified.
- Class 3: referenced, modified.
- Tanenbaum & Bos, Modern Operating Systems: 4th ed., Global Edition (c) 2015 Pearson Education Limited. All rights reserved.
Second-Chance Algorithm - Figure 3-15. Operation of second chance. (a) Pages sorted in FIFO order. (b) Page list if a page fault occurs at time 20 and A has its R bit set. The numbers above the pages are their load times.
- Tanenbaum & Bos, Modern Operating Systems: 4th ed., Global Edition (c) 2015 Pearson Education Limited. All rights reserved.
Clock Page Replacement Algorithm - Figure 3-16. The clock page replacement algorithm.
- Tanenbaum & Bos, Modern Operating Systems: 4th ed., Global Edition (c) 2015 Pearson Education Limited. All rights reserved.
- Figure 3-17. The aging algorithm simulates LRU in software. Shown are six pages for five clock ticks. The five clock ticks are represented by (a) to (e).
- Tanenbaum & Bos, Modern Operating Systems: 4th ed., Global Edition (c) 2015 Pearson Education Limited. All rights reserved.
Working Set Algorithm (1) - Figure 3-18. The working set is the set of pages used by the k most recent memory references. The function w(k, t) is the size of the working set at time t.
- Tanenbaum & Bos, Modern Operating Systems: 4th ed., Global Edition (c) 2015 Pearson Education Limited. All rights reserved.
Working Set Algorithm (2) - Figure 3-19. The working set algorithm.
- Tanenbaum & Bos, Modern Operating Systems: 4th ed., Global Edition (c) 2015 Pearson Education Limited. All rights reserved.
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