The Paging Daemon
Most OS have one or more system processes responsible for implementing the VM page cache replacement policy.
- A daemon is an autonomous system process that periodically performs some housekeeping task.
The paging daemon prepares for page eviction before the need arises.
- Wake up when free memory becomes low.
- Clean dirty pages by pushing to backing store.
- Maintain ordered lists of eviction candidates.
- Decide how much memory to allocate to file cache, VM, etc.