blob: 5652be858e5e320c7a748d4e6a407c66baaa62a0
1 | /* |
2 | * linux/mm/mmzone.c |
3 | * |
4 | * management codes for pgdats, zones and page flags |
5 | */ |
6 | |
7 | |
8 | #include <linux/stddef.h> |
9 | #include <linux/mm.h> |
10 | #include <linux/mmzone.h> |
11 | |
12 | struct pglist_data *first_online_pgdat(void) |
13 | { |
14 | return NODE_DATA(first_online_node); |
15 | } |
16 | |
17 | struct pglist_data *next_online_pgdat(struct pglist_data *pgdat) |
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 */ |
55 | struct zoneref *__next_zones_zonelist(struct zoneref *z, |
56 | enum zone_type highest_zoneidx, |
57 | nodemask_t *nodes) |
58 | { |
59 | /* |
60 | * Find the next suitable zone to use for the allocation. |
61 | * Only filter based on nodemask if it's set |
62 | */ |
63 | if (likely(nodes == NULL)) |
64 | while (zonelist_zone_idx(z) > highest_zoneidx) |
65 | z++; |
66 | else |
67 | while (zonelist_zone_idx(z) > highest_zoneidx || |
68 | (z->zone && !zref_in_nodemask(z, nodes))) |
69 | z++; |
70 | |
71 | return z; |
72 | } |
73 | |
74 | #ifdef CONFIG_ARCH_HAS_HOLES_MEMORYMODEL |
75 | bool memmap_valid_within(unsigned long pfn, |
76 | struct page *page, struct zone *zone) |
77 | { |
78 | if (page_to_pfn(page) != pfn) |
79 | return false; |
80 | |
81 | if (page_zone(page) != zone) |
82 | return false; |
83 | |
84 | return true; |
85 | } |
86 | #endif /* CONFIG_ARCH_HAS_HOLES_MEMORYMODEL */ |
87 | |
88 | void lruvec_init(struct lruvec *lruvec) |
89 | { |
90 | enum lru_list lru; |
91 | |
92 | memset(lruvec, 0, sizeof(struct lruvec)); |
93 | |
94 | for_each_lru(lru) |
95 | INIT_LIST_HEAD(&lruvec->lists[lru]); |
96 | } |
97 | |
98 | #if defined(CONFIG_NUMA_BALANCING) && !defined(LAST_CPUPID_NOT_IN_PAGE_FLAGS) |
99 | int page_cpupid_xchg_last(struct page *page, int cpupid) |
100 | { |
101 | unsigned long old_flags, flags; |
102 | int last_cpupid; |
103 | |
104 | do { |
105 | old_flags = flags = page->flags; |
106 | last_cpupid = page_cpupid_last(page); |
107 | |
108 | flags &= ~(LAST_CPUPID_MASK << LAST_CPUPID_PGSHIFT); |
109 | flags |= (cpupid & LAST_CPUPID_MASK) << LAST_CPUPID_PGSHIFT; |
110 | } while (unlikely(cmpxchg(&page->flags, old_flags, flags) != old_flags)); |
111 | |
112 | return last_cpupid; |
113 | } |
114 | #endif |
115 |