[PATCH] reduce MAX_NR_ZONES: make ZONE_HIGHMEM optional
[linux-2.6-block.git] / include / linux / gfp.h
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1da177e4
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1#ifndef __LINUX_GFP_H
2#define __LINUX_GFP_H
3
4#include <linux/mmzone.h>
5#include <linux/stddef.h>
6#include <linux/linkage.h>
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7
8struct vm_area_struct;
9
10/*
11 * GFP bitmasks..
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12 *
13 * Zone modifiers (see linux/mmzone.h - low three bits)
14 *
15 * These may be masked by GFP_ZONEMASK to make allocations with this bit
16 * set fall back to ZONE_NORMAL.
17 *
18 * Do not put any conditional on these. If necessary modify the definitions
19 * without the underscores and use the consistently. The definitions here may
20 * be used in bit comparisons.
1da177e4 21 */
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22#define __GFP_DMA ((__force gfp_t)0x01u)
23#define __GFP_HIGHMEM ((__force gfp_t)0x02u)
e53ef38d 24#define __GFP_DMA32 ((__force gfp_t)0x04u)
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25
26/*
27 * Action modifiers - doesn't change the zoning
28 *
29 * __GFP_REPEAT: Try hard to allocate the memory, but the allocation attempt
30 * _might_ fail. This depends upon the particular VM implementation.
31 *
32 * __GFP_NOFAIL: The VM implementation _must_ retry infinitely: the caller
33 * cannot handle allocation failures.
34 *
35 * __GFP_NORETRY: The VM implementation must not retry indefinitely.
36 */
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37#define __GFP_WAIT ((__force gfp_t)0x10u) /* Can wait and reschedule? */
38#define __GFP_HIGH ((__force gfp_t)0x20u) /* Should access emergency pools? */
39#define __GFP_IO ((__force gfp_t)0x40u) /* Can start physical IO? */
40#define __GFP_FS ((__force gfp_t)0x80u) /* Can call down to low-level FS? */
41#define __GFP_COLD ((__force gfp_t)0x100u) /* Cache-cold page required */
42#define __GFP_NOWARN ((__force gfp_t)0x200u) /* Suppress page allocation failure warning */
43#define __GFP_REPEAT ((__force gfp_t)0x400u) /* Retry the allocation. Might fail */
44#define __GFP_NOFAIL ((__force gfp_t)0x800u) /* Retry for ever. Cannot fail */
45#define __GFP_NORETRY ((__force gfp_t)0x1000u)/* Do not retry. Might fail */
46#define __GFP_NO_GROW ((__force gfp_t)0x2000u)/* Slab internal usage */
47#define __GFP_COMP ((__force gfp_t)0x4000u)/* Add compound page metadata */
48#define __GFP_ZERO ((__force gfp_t)0x8000u)/* Return zeroed page on success */
49#define __GFP_NOMEMALLOC ((__force gfp_t)0x10000u) /* Don't use emergency reserves */
2d6c666e 50#define __GFP_HARDWALL ((__force gfp_t)0x20000u) /* Enforce hardwall cpuset memory allocs */
1da177e4 51
b84a35be 52#define __GFP_BITS_SHIFT 20 /* Room for 20 __GFP_FOO bits */
af4ca457 53#define __GFP_BITS_MASK ((__force gfp_t)((1 << __GFP_BITS_SHIFT) - 1))
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54
55/* if you forget to add the bitmask here kernel will crash, period */
56#define GFP_LEVEL_MASK (__GFP_WAIT|__GFP_HIGH|__GFP_IO|__GFP_FS| \
57 __GFP_COLD|__GFP_NOWARN|__GFP_REPEAT| \
b84a35be 58 __GFP_NOFAIL|__GFP_NORETRY|__GFP_NO_GROW|__GFP_COMP| \
2d6c666e 59 __GFP_NOMEMALLOC|__GFP_HARDWALL)
1da177e4 60
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61/* This equals 0, but use constants in case they ever change */
62#define GFP_NOWAIT (GFP_ATOMIC & ~__GFP_HIGH)
4eac915d 63/* GFP_ATOMIC means both !wait (__GFP_WAIT not set) and use emergency pool */
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64#define GFP_ATOMIC (__GFP_HIGH)
65#define GFP_NOIO (__GFP_WAIT)
66#define GFP_NOFS (__GFP_WAIT | __GFP_IO)
67#define GFP_KERNEL (__GFP_WAIT | __GFP_IO | __GFP_FS)
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68#define GFP_USER (__GFP_WAIT | __GFP_IO | __GFP_FS | __GFP_HARDWALL)
69#define GFP_HIGHUSER (__GFP_WAIT | __GFP_IO | __GFP_FS | __GFP_HARDWALL | \
70 __GFP_HIGHMEM)
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71
72/* Flag - indicates that the buffer will be suitable for DMA. Ignored on some
73 platforms, used as appropriate on others */
74
75#define GFP_DMA __GFP_DMA
76
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77/* 4GB DMA on some platforms */
78#define GFP_DMA32 __GFP_DMA32
79
80
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81static inline int gfp_zone(gfp_t gfp)
82{
83 int zone = GFP_ZONEMASK & (__force int) gfp;
84 BUG_ON(zone >= GFP_ZONETYPES);
85 return zone;
86}
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87
88/*
89 * There is only one page-allocator function, and two main namespaces to
90 * it. The alloc_page*() variants return 'struct page *' and as such
91 * can allocate highmem pages, the *get*page*() variants return
92 * virtual kernel addresses to the allocated page(s).
93 */
94
95/*
96 * We get the zone list from the current node and the gfp_mask.
97 * This zone list contains a maximum of MAXNODES*MAX_NR_ZONES zones.
98 *
99 * For the normal case of non-DISCONTIGMEM systems the NODE_DATA() gets
100 * optimized to &contig_page_data at compile-time.
101 */
102
103#ifndef HAVE_ARCH_FREE_PAGE
104static inline void arch_free_page(struct page *page, int order) { }
105#endif
106
107extern struct page *
dd0fc66f 108FASTCALL(__alloc_pages(gfp_t, unsigned int, struct zonelist *));
1da177e4 109
dd0fc66f 110static inline struct page *alloc_pages_node(int nid, gfp_t gfp_mask,
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111 unsigned int order)
112{
113 if (unlikely(order >= MAX_ORDER))
114 return NULL;
115
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116 /* Unknown node is current node */
117 if (nid < 0)
118 nid = numa_node_id();
119
1da177e4 120 return __alloc_pages(gfp_mask, order,
af4ca457 121 NODE_DATA(nid)->node_zonelists + gfp_zone(gfp_mask));
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122}
123
124#ifdef CONFIG_NUMA
dd0fc66f 125extern struct page *alloc_pages_current(gfp_t gfp_mask, unsigned order);
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126
127static inline struct page *
dd0fc66f 128alloc_pages(gfp_t gfp_mask, unsigned int order)
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129{
130 if (unlikely(order >= MAX_ORDER))
131 return NULL;
132
133 return alloc_pages_current(gfp_mask, order);
134}
dd0fc66f 135extern struct page *alloc_page_vma(gfp_t gfp_mask,
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136 struct vm_area_struct *vma, unsigned long addr);
137#else
138#define alloc_pages(gfp_mask, order) \
139 alloc_pages_node(numa_node_id(), gfp_mask, order)
140#define alloc_page_vma(gfp_mask, vma, addr) alloc_pages(gfp_mask, 0)
141#endif
142#define alloc_page(gfp_mask) alloc_pages(gfp_mask, 0)
143
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144extern unsigned long FASTCALL(__get_free_pages(gfp_t gfp_mask, unsigned int order));
145extern unsigned long FASTCALL(get_zeroed_page(gfp_t gfp_mask));
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146
147#define __get_free_page(gfp_mask) \
148 __get_free_pages((gfp_mask),0)
149
150#define __get_dma_pages(gfp_mask, order) \
151 __get_free_pages((gfp_mask) | GFP_DMA,(order))
152
153extern void FASTCALL(__free_pages(struct page *page, unsigned int order));
154extern void FASTCALL(free_pages(unsigned long addr, unsigned int order));
155extern void FASTCALL(free_hot_page(struct page *page));
156extern void FASTCALL(free_cold_page(struct page *page));
157
158#define __free_page(page) __free_pages((page), 0)
159#define free_page(addr) free_pages((addr),0)
160
161void page_alloc_init(void);
4ae7c039 162#ifdef CONFIG_NUMA
8fce4d8e 163void drain_node_pages(int node);
4ae7c039 164#else
8fce4d8e 165static inline void drain_node_pages(int node) { };
4ae7c039 166#endif
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167
168#endif /* __LINUX_GFP_H */