Help¶

This implements a Not Recently Used page eviction algorithm. A periodic timer will clear the accessed state of all virtual pages. When a page frame needs to be evicted, the algorithm will prefer to evict page frames using an ascending order of priority:

recently accessed, dirty

recently accessed, clean

not recently accessed, dirty

not recently accessed, clean

Direct dependencies¶

(Includes any dependencies from ifs and menus.)

Kconfig definition¶

At subsys/demand_paging/eviction/Kconfig:17

Included via Kconfig:8 → Kconfig.zephyr:34 → subsys/Kconfig:61 → subsys/demand_paging/Kconfig:7

Menu path: (Top) → Sub Systems and OS Services → Demand Paging modules → Page frame eviction algorithms

config EVICTION_NRU
    bool "Not Recently Used (NRU) page eviction algorithm"
    depends on <choice EVICTION_CHOICE: Page frame eviction algorithms>
    help
      This implements a Not Recently Used page eviction algorithm.
      A periodic timer will clear the accessed state of all virtual pages.
      When a page frame needs to be evicted, the algorithm will prefer to
      evict page frames using an ascending order of priority:

       - recently accessed, dirty
       - recently accessed, clean
       - not recently accessed, dirty
       - not recently accessed, clean

(The ‘depends on’ condition includes propagated dependencies from ifs and menus.)