内存管理之数据结构

struct zone {
  unsigned long watermark[NR_WMARK];
  struct pglist_data *zone_pgdat;
  struct per_cpu_pageset __percpu *pageset;
  struct free_area free_area[MAX_ORDER];
  ......
}

enum zone_watermarks {
  WMARK_MIN,
  WMARK_LOW,
  WMARK_HIGH,
  NR_WMARK
};

struct per_cpu_pageset {
  struct per_cpu_pages pcp;
  ......
};

struct per_cpu_pages {
  int count;  /* number of pages in the list */
  int high;  /* high watermark, emptying needed */
  int batch;  /* chunk size for buddy add/remove */
  struct list_head lists[MIGRATE_PCPTYPES];
};

struct free_area {
  struct list_head free_list[MIGRATE_TYPES];
  unsigned long  nr_free;
};

enum migratetype {
 MIGRATE_UNMOVABLE,
 MIGRATE_MOVABLE,
 MIGRATE_RECLAIMABLE,
 MIGRATE_PCPTYPES, /* the number of types on the pcp lists */
 MIGRATE_HIGHATOMIC = MIGRATE_PCPTYPES,
 MIGRATE_CMA,
 MIGRATE_ISOLATE, /* can't allocate from here */
 MIGRATE_TYPES
};

typedef struct pglist_data {
  struct zone node_zones[MAX_NR_ZONES];
  struct zonelist node_zonelists[MAX_ZONELISTS];
  enum zone_type kswapd_classzone_idx;
  struct lruvec  lruvec;
  ......
}

enum zone_type {
  ZONE_DMA32,
  ZONE_NORMAL,
  ZONE_MOVABLE,
  ......
  __MAX_NR_ZONES
};

struct lruvec {
 struct list_head  lists[NR_LRU_LISTS];
 struct zone_reclaim_stat reclaim_stat;
 atomic_long_t   inactive_age;
 unsigned long   refaults;
};

enum lru_list {
 LRU_INACTIVE_ANON = LRU_BASE,
 LRU_ACTIVE_ANON = LRU_BASE + LRU_ACTIVE,
 LRU_INACTIVE_FILE = LRU_BASE + LRU_FILE,
 LRU_ACTIVE_FILE = LRU_BASE + LRU_FILE + LRU_ACTIVE,
 LRU_UNEVICTABLE,
 NR_LRU_LISTS
};