Apr 15, 2026 · The Second Chance Page Replacement Algorithm is an improvement over FIFO that avoids removing frequently used pages by using a reference bit. When a page is accessed, its …

When physical memory is full and we need to choose a page to remove, run the clock algorithm. Clock hand “sweeps” over pages, rotating back to start if reaching the end. Every time the hand visits a …

The clock algorithm keeps a circular list of pages in memory, with the "hand" (iterator) pointing to the last examined page frame in the list. When a page fault occurs and no empty frames exist, then the R …

The Second Chance or Clock Page Replacement Algorithm is an improvement over the FIFO algorithm. The main idea here is to give pages a second chance before replacing them.

This is an efficient way to approximate LRU. Clock algorithm: keep "use" bit for each page frame, hardware sets the appropriate bit on every memory reference. The operating system clears the bits …

Dive into the "Clock Page Replacement" lecture in our Operating Systems course, where we explore the clock algorithm as an efficient approximation of the Least Recently Used (LRU) page...

Like CLOCK, WSClock walks through the frames in order, looking for a good candidate for replacement, cleaning the reference bits as it goes. If the frame has been referenced since it was last inspected, it …

Mar 18, 2024 · This algorithm can help improve system performance in real-time systems by reducing the number of page faults and ensuring that frequently accessed pages remain in primary memory.

The second chance algorithm (which some people call the clock algorithm) works just like FIFO, but it skips over any pages with the use bit set (and clears the use bit).

The CLOCK (i.e., Second- Chance) algorithm is an approximation of the well-known Least Recently Used (LRU) algorithm, which evicts the least recently accessed (referenced) pages.