The Page Caching Problem
Each thread/process/job utters a stream of page references.
- reference string: e.g., abcabcdabce..
The OS tries to minimize the number of faults incurred.
- The set of pages (the working set) actively used by each job changes relatively slowly.
- Try to arrange for the resident set of pages for each active job to closely approximate its working set.
Replacement policy is the key.
- On each page fault, select a victim page to evict from memory; read the new page into the victim’s frame.
- Most systems try to approximate an LRU policy.