Paging daemon on Linux
- Proactively manages memory such that a (small) pool of Page Frames are always free for use (~2% of memory), meaning that if it does its job effectively, Processes never have to wait for Replacement Algorithm
- Memory usage will gradually accumulate over time, as any process that needs memory will be supplied it, until eventually it reaches a steady state of ~2% free, maintained by the intermittent management of kswapd
- If you run a program multiple times, its pages are already in memory, so it doesn’t have to refetch them
- If you open a file, its pages remain in memory, so they don’t have to be refetched
- Basically this behavior creates Caching behavior
- When kswap is running
- If a page is Dirty, write it out to disk to clean it.
- Uses a modified version of Second Chance for page eviction
- Evicts pages