Linux Kernel  3.7.1
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mmzone.c
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1 /*
2  * linux/mm/mmzone.c
3  *
4  * management codes for pgdats and zones.
5  */
6 
7 
8 #include <linux/stddef.h>
9 #include <linux/mm.h>
10 #include <linux/mmzone.h>
11 
13 {
15 }
16 
18 {
19  int nid = next_online_node(pgdat->node_id);
20 
21  if (nid == MAX_NUMNODES)
22  return NULL;
23  return NODE_DATA(nid);
24 }
25 
26 /*
27  * next_zone - helper magic for for_each_zone()
28  */
29 struct zone *next_zone(struct zone *zone)
30 {
31  pg_data_t *pgdat = zone->zone_pgdat;
32 
33  if (zone < pgdat->node_zones + MAX_NR_ZONES - 1)
34  zone++;
35  else {
36  pgdat = next_online_pgdat(pgdat);
37  if (pgdat)
38  zone = pgdat->node_zones;
39  else
40  zone = NULL;
41  }
42  return zone;
43 }
44 
45 static inline int zref_in_nodemask(struct zoneref *zref, nodemask_t *nodes)
46 {
47 #ifdef CONFIG_NUMA
48  return node_isset(zonelist_node_idx(zref), *nodes);
49 #else
50  return 1;
51 #endif /* CONFIG_NUMA */
52 }
53 
54 /* Returns the next zone at or below highest_zoneidx in a zonelist */
56  enum zone_type highest_zoneidx,
57  nodemask_t *nodes,
58  struct zone **zone)
59 {
60  /*
61  * Find the next suitable zone to use for the allocation.
62  * Only filter based on nodemask if it's set
63  */
64  if (likely(nodes == NULL))
65  while (zonelist_zone_idx(z) > highest_zoneidx)
66  z++;
67  else
68  while (zonelist_zone_idx(z) > highest_zoneidx ||
69  (z->zone && !zref_in_nodemask(z, nodes)))
70  z++;
71 
72  *zone = zonelist_zone(z);
73  return z;
74 }
75 
76 #ifdef CONFIG_ARCH_HAS_HOLES_MEMORYMODEL
77 int memmap_valid_within(unsigned long pfn,
78  struct page *page, struct zone *zone)
79 {
80  if (page_to_pfn(page) != pfn)
81  return 0;
82 
83  if (page_zone(page) != zone)
84  return 0;
85 
86  return 1;
87 }
88 #endif /* CONFIG_ARCH_HAS_HOLES_MEMORYMODEL */
89 
90 void lruvec_init(struct lruvec *lruvec)
91 {
92  enum lru_list lru;
93 
94  memset(lruvec, 0, sizeof(struct lruvec));
95 
96  for_each_lru(lru)
97  INIT_LIST_HEAD(&lruvec->lists[lru]);
98 }