Three frames. One request at a time.
All frames start empty. Follow the same request string with each policy. F means fault; H means hit.
Request 1: page 7 — Fault
Page 7 is absent. This request counts as one fault, including when a free frame is available.
Use empty frame 0
No eviction is necessary. We use free frames in increasing frame-number order.
Load page 7 into frame 0
Fill the free frame. The loaded page is now most recently used.
Request 2: page 0 — Fault
Page 0 is absent. This request counts as one fault, including when a free frame is available.
Use empty frame 1
No eviction is necessary. We use free frames in increasing frame-number order.
Load page 0 into frame 1
Fill the free frame. The loaded page is now most recently used.
Request 3: page 1 — Fault
Page 1 is absent. This request counts as one fault, including when a free frame is available.
Use empty frame 2
No eviction is necessary. We use free frames in increasing frame-number order.
Load page 1 into frame 2
Fill the free frame. The loaded page is now most recently used.
Request 4: page 2 — Fault
Page 2 is absent. This request counts as one fault, including when a free frame is available.
Evict page 7 from frame 0
Page 7 was accessed least recently.
Load page 2 into frame 0
Replace page 7. A modified victim would first need a write-back. The loaded page is now most recently used.
Request 5: page 0 — Hit
Page 0 is already in frame 1. No page needs to be loaded or evicted.
Hit: update the bookkeeping
Page 0 becomes most recently used. Only the recency list moves; physical frames stay fixed.
Request 6: page 3 — Fault
Page 3 is absent. This request counts as one fault, including when a free frame is available.
Evict page 1 from frame 2
Page 1 was accessed least recently.
Load page 3 into frame 2
Replace page 1. A modified victim would first need a write-back. The loaded page is now most recently used.
Request 7: page 0 — Hit
Page 0 is already in frame 1. No page needs to be loaded or evicted.
Hit: update the bookkeeping
Page 0 becomes most recently used. Only the recency list moves; physical frames stay fixed.
Request 8: page 4 — Fault
Page 4 is absent. This request counts as one fault, including when a free frame is available.
Evict page 2 from frame 0
Page 2 was accessed least recently.
Load page 4 into frame 0
Replace page 2. A modified victim would first need a write-back. The loaded page is now most recently used.
Request 9: page 2 — Fault
Page 2 is absent. This request counts as one fault, including when a free frame is available.
Evict page 3 from frame 2
Page 3 was accessed least recently.
Load page 2 into frame 2
Replace page 3. A modified victim would first need a write-back. The loaded page is now most recently used.
Request 10: page 3 — Fault
Page 3 is absent. This request counts as one fault, including when a free frame is available.
Evict page 0 from frame 1
Page 0 was accessed least recently.
Load page 3 into frame 1
Replace page 0. A modified victim would first need a write-back. The loaded page is now most recently used.
Three frames. One request at a time.
All frames start empty. Follow the same request string with each policy. F means fault; H means hit.
Every access updates recency. The list can change on a hit even when physical memory does not.