vmscan: detect mapped file pages used only once
[deliverable/linux.git] / include / linux / gfp.h
CommitLineData
1da177e4
LT
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>
082edb7b 7#include <linux/topology.h>
6484eb3e 8#include <linux/mmdebug.h>
1da177e4
LT
9
10struct vm_area_struct;
11
12/*
13 * GFP bitmasks..
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14 *
15 * Zone modifiers (see linux/mmzone.h - low three bits)
16 *
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17 * Do not put any conditional on these. If necessary modify the definitions
18 * without the underscores and use the consistently. The definitions here may
19 * be used in bit comparisons.
1da177e4 20 */
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21#define __GFP_DMA ((__force gfp_t)0x01u)
22#define __GFP_HIGHMEM ((__force gfp_t)0x02u)
e53ef38d 23#define __GFP_DMA32 ((__force gfp_t)0x04u)
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24#define __GFP_MOVABLE ((__force gfp_t)0x08u) /* Page is movable */
25#define GFP_ZONEMASK (__GFP_DMA|__GFP_HIGHMEM|__GFP_DMA32|__GFP_MOVABLE)
1da177e4
LT
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.
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36 *
37 * __GFP_MOVABLE: Flag that this page will be movable by the page migration
38 * mechanism or reclaimed
1da177e4 39 */
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40#define __GFP_WAIT ((__force gfp_t)0x10u) /* Can wait and reschedule? */
41#define __GFP_HIGH ((__force gfp_t)0x20u) /* Should access emergency pools? */
42#define __GFP_IO ((__force gfp_t)0x40u) /* Can start physical IO? */
43#define __GFP_FS ((__force gfp_t)0x80u) /* Can call down to low-level FS? */
44#define __GFP_COLD ((__force gfp_t)0x100u) /* Cache-cold page required */
45#define __GFP_NOWARN ((__force gfp_t)0x200u) /* Suppress page allocation failure warning */
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46#define __GFP_REPEAT ((__force gfp_t)0x400u) /* See above */
47#define __GFP_NOFAIL ((__force gfp_t)0x800u) /* See above */
48#define __GFP_NORETRY ((__force gfp_t)0x1000u)/* See above */
af4ca457
AV
49#define __GFP_COMP ((__force gfp_t)0x4000u)/* Add compound page metadata */
50#define __GFP_ZERO ((__force gfp_t)0x8000u)/* Return zeroed page on success */
51#define __GFP_NOMEMALLOC ((__force gfp_t)0x10000u) /* Don't use emergency reserves */
2d6c666e 52#define __GFP_HARDWALL ((__force gfp_t)0x20000u) /* Enforce hardwall cpuset memory allocs */
9b819d20 53#define __GFP_THISNODE ((__force gfp_t)0x40000u)/* No fallback, no policies */
e12ba74d 54#define __GFP_RECLAIMABLE ((__force gfp_t)0x80000u) /* Page is reclaimable */
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55
56#ifdef CONFIG_KMEMCHECK
2dff4405 57#define __GFP_NOTRACK ((__force gfp_t)0x200000u) /* Don't track with kmemcheck */
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58#else
59#define __GFP_NOTRACK ((__force gfp_t)0)
60#endif
1da177e4 61
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62/*
63 * This may seem redundant, but it's a way of annotating false positives vs.
64 * allocations that simply cannot be supported (e.g. page tables).
65 */
66#define __GFP_NOTRACK_FALSE_POSITIVE (__GFP_NOTRACK)
67
68#define __GFP_BITS_SHIFT 22 /* Room for 22 __GFP_FOO bits */
af4ca457 69#define __GFP_BITS_MASK ((__force gfp_t)((1 << __GFP_BITS_SHIFT) - 1))
1da177e4 70
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JD
71/* This equals 0, but use constants in case they ever change */
72#define GFP_NOWAIT (GFP_ATOMIC & ~__GFP_HIGH)
4eac915d 73/* GFP_ATOMIC means both !wait (__GFP_WAIT not set) and use emergency pool */
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74#define GFP_ATOMIC (__GFP_HIGH)
75#define GFP_NOIO (__GFP_WAIT)
76#define GFP_NOFS (__GFP_WAIT | __GFP_IO)
77#define GFP_KERNEL (__GFP_WAIT | __GFP_IO | __GFP_FS)
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78#define GFP_TEMPORARY (__GFP_WAIT | __GFP_IO | __GFP_FS | \
79 __GFP_RECLAIMABLE)
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80#define GFP_USER (__GFP_WAIT | __GFP_IO | __GFP_FS | __GFP_HARDWALL)
81#define GFP_HIGHUSER (__GFP_WAIT | __GFP_IO | __GFP_FS | __GFP_HARDWALL | \
82 __GFP_HIGHMEM)
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83#define GFP_HIGHUSER_MOVABLE (__GFP_WAIT | __GFP_IO | __GFP_FS | \
84 __GFP_HARDWALL | __GFP_HIGHMEM | \
85 __GFP_MOVABLE)
452aa699 86#define GFP_IOFS (__GFP_IO | __GFP_FS)
1da177e4 87
77f700da 88#ifdef CONFIG_NUMA
980128f2 89#define GFP_THISNODE (__GFP_THISNODE | __GFP_NOWARN | __GFP_NORETRY)
77f700da 90#else
f2e97df6 91#define GFP_THISNODE ((__force gfp_t)0)
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CL
92#endif
93
6cb06229 94/* This mask makes up all the page movable related flags */
e12ba74d 95#define GFP_MOVABLE_MASK (__GFP_RECLAIMABLE|__GFP_MOVABLE)
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96
97/* Control page allocator reclaim behavior */
98#define GFP_RECLAIM_MASK (__GFP_WAIT|__GFP_HIGH|__GFP_IO|__GFP_FS|\
99 __GFP_NOWARN|__GFP_REPEAT|__GFP_NOFAIL|\
100 __GFP_NORETRY|__GFP_NOMEMALLOC)
101
7e85ee0c 102/* Control slab gfp mask during early boot */
dcce284a 103#define GFP_BOOT_MASK __GFP_BITS_MASK & ~(__GFP_WAIT|__GFP_IO|__GFP_FS)
7e85ee0c 104
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105/* Control allocation constraints */
106#define GFP_CONSTRAINT_MASK (__GFP_HARDWALL|__GFP_THISNODE)
107
108/* Do not use these with a slab allocator */
109#define GFP_SLAB_BUG_MASK (__GFP_DMA32|__GFP_HIGHMEM|~__GFP_BITS_MASK)
980128f2 110
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111/* Flag - indicates that the buffer will be suitable for DMA. Ignored on some
112 platforms, used as appropriate on others */
113
114#define GFP_DMA __GFP_DMA
115
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116/* 4GB DMA on some platforms */
117#define GFP_DMA32 __GFP_DMA32
118
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119/* Convert GFP flags to their corresponding migrate type */
120static inline int allocflags_to_migratetype(gfp_t gfp_flags)
121{
122 WARN_ON((gfp_flags & GFP_MOVABLE_MASK) == GFP_MOVABLE_MASK);
123
124 if (unlikely(page_group_by_mobility_disabled))
125 return MIGRATE_UNMOVABLE;
126
127 /* Group based on mobility */
128 return (((gfp_flags & __GFP_MOVABLE) != 0) << 1) |
129 ((gfp_flags & __GFP_RECLAIMABLE) != 0);
130}
a2f1b424 131
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132#ifdef CONFIG_HIGHMEM
133#define OPT_ZONE_HIGHMEM ZONE_HIGHMEM
134#else
135#define OPT_ZONE_HIGHMEM ZONE_NORMAL
136#endif
137
4b51d669 138#ifdef CONFIG_ZONE_DMA
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139#define OPT_ZONE_DMA ZONE_DMA
140#else
141#define OPT_ZONE_DMA ZONE_NORMAL
4b51d669 142#endif
b70d94ee 143
4e4785bc 144#ifdef CONFIG_ZONE_DMA32
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145#define OPT_ZONE_DMA32 ZONE_DMA32
146#else
147#define OPT_ZONE_DMA32 ZONE_NORMAL
4e4785bc 148#endif
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149
150/*
151 * GFP_ZONE_TABLE is a word size bitstring that is used for looking up the
152 * zone to use given the lowest 4 bits of gfp_t. Entries are ZONE_SHIFT long
153 * and there are 16 of them to cover all possible combinations of
154 * __GFP_DMA, __GFP_DMA32, __GFP_MOVABLE and __GFP_HIGHMEM
155 *
156 * The zone fallback order is MOVABLE=>HIGHMEM=>NORMAL=>DMA32=>DMA.
157 * But GFP_MOVABLE is not only a zone specifier but also an allocation
158 * policy. Therefore __GFP_MOVABLE plus another zone selector is valid.
159 * Only 1bit of the lowest 3 bit (DMA,DMA32,HIGHMEM) can be set to "1".
160 *
161 * bit result
162 * =================
163 * 0x0 => NORMAL
164 * 0x1 => DMA or NORMAL
165 * 0x2 => HIGHMEM or NORMAL
166 * 0x3 => BAD (DMA+HIGHMEM)
167 * 0x4 => DMA32 or DMA or NORMAL
168 * 0x5 => BAD (DMA+DMA32)
169 * 0x6 => BAD (HIGHMEM+DMA32)
170 * 0x7 => BAD (HIGHMEM+DMA32+DMA)
171 * 0x8 => NORMAL (MOVABLE+0)
172 * 0x9 => DMA or NORMAL (MOVABLE+DMA)
173 * 0xa => MOVABLE (Movable is valid only if HIGHMEM is set too)
174 * 0xb => BAD (MOVABLE+HIGHMEM+DMA)
175 * 0xc => DMA32 (MOVABLE+HIGHMEM+DMA32)
176 * 0xd => BAD (MOVABLE+DMA32+DMA)
177 * 0xe => BAD (MOVABLE+DMA32+HIGHMEM)
178 * 0xf => BAD (MOVABLE+DMA32+HIGHMEM+DMA)
179 *
180 * ZONES_SHIFT must be <= 2 on 32 bit platforms.
181 */
182
183#if 16 * ZONES_SHIFT > BITS_PER_LONG
184#error ZONES_SHIFT too large to create GFP_ZONE_TABLE integer
185#endif
186
187#define GFP_ZONE_TABLE ( \
188 (ZONE_NORMAL << 0 * ZONES_SHIFT) \
189 | (OPT_ZONE_DMA << __GFP_DMA * ZONES_SHIFT) \
190 | (OPT_ZONE_HIGHMEM << __GFP_HIGHMEM * ZONES_SHIFT) \
191 | (OPT_ZONE_DMA32 << __GFP_DMA32 * ZONES_SHIFT) \
192 | (ZONE_NORMAL << __GFP_MOVABLE * ZONES_SHIFT) \
193 | (OPT_ZONE_DMA << (__GFP_MOVABLE | __GFP_DMA) * ZONES_SHIFT) \
194 | (ZONE_MOVABLE << (__GFP_MOVABLE | __GFP_HIGHMEM) * ZONES_SHIFT)\
195 | (OPT_ZONE_DMA32 << (__GFP_MOVABLE | __GFP_DMA32) * ZONES_SHIFT)\
196)
197
198/*
199 * GFP_ZONE_BAD is a bitmap for all combination of __GFP_DMA, __GFP_DMA32
200 * __GFP_HIGHMEM and __GFP_MOVABLE that are not permitted. One flag per
201 * entry starting with bit 0. Bit is set if the combination is not
202 * allowed.
203 */
204#define GFP_ZONE_BAD ( \
205 1 << (__GFP_DMA | __GFP_HIGHMEM) \
206 | 1 << (__GFP_DMA | __GFP_DMA32) \
207 | 1 << (__GFP_DMA32 | __GFP_HIGHMEM) \
208 | 1 << (__GFP_DMA | __GFP_DMA32 | __GFP_HIGHMEM) \
209 | 1 << (__GFP_MOVABLE | __GFP_HIGHMEM | __GFP_DMA) \
210 | 1 << (__GFP_MOVABLE | __GFP_DMA32 | __GFP_DMA) \
211 | 1 << (__GFP_MOVABLE | __GFP_DMA32 | __GFP_HIGHMEM) \
212 | 1 << (__GFP_MOVABLE | __GFP_DMA32 | __GFP_DMA | __GFP_HIGHMEM)\
213)
214
215static inline enum zone_type gfp_zone(gfp_t flags)
216{
217 enum zone_type z;
218 int bit = flags & GFP_ZONEMASK;
219
220 z = (GFP_ZONE_TABLE >> (bit * ZONES_SHIFT)) &
221 ((1 << ZONES_SHIFT) - 1);
222
223 if (__builtin_constant_p(bit))
8c87df45 224 MAYBE_BUILD_BUG_ON((GFP_ZONE_BAD >> bit) & 1);
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225 else {
226#ifdef CONFIG_DEBUG_VM
227 BUG_ON((GFP_ZONE_BAD >> bit) & 1);
4e4785bc 228#endif
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229 }
230 return z;
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231}
232
1da177e4
LT
233/*
234 * There is only one page-allocator function, and two main namespaces to
235 * it. The alloc_page*() variants return 'struct page *' and as such
236 * can allocate highmem pages, the *get*page*() variants return
237 * virtual kernel addresses to the allocated page(s).
238 */
239
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MG
240static inline int gfp_zonelist(gfp_t flags)
241{
242 if (NUMA_BUILD && unlikely(flags & __GFP_THISNODE))
243 return 1;
244
245 return 0;
246}
247
1da177e4
LT
248/*
249 * We get the zone list from the current node and the gfp_mask.
250 * This zone list contains a maximum of MAXNODES*MAX_NR_ZONES zones.
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251 * There are two zonelists per node, one for all zones with memory and
252 * one containing just zones from the node the zonelist belongs to.
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LT
253 *
254 * For the normal case of non-DISCONTIGMEM systems the NODE_DATA() gets
255 * optimized to &contig_page_data at compile-time.
256 */
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257static inline struct zonelist *node_zonelist(int nid, gfp_t flags)
258{
54a6eb5c 259 return NODE_DATA(nid)->node_zonelists + gfp_zonelist(flags);
0e88460d 260}
1da177e4
LT
261
262#ifndef HAVE_ARCH_FREE_PAGE
263static inline void arch_free_page(struct page *page, int order) { }
264#endif
cc102509
NP
265#ifndef HAVE_ARCH_ALLOC_PAGE
266static inline void arch_alloc_page(struct page *page, int order) { }
267#endif
1da177e4 268
e4048e5d 269struct page *
d239171e 270__alloc_pages_nodemask(gfp_t gfp_mask, unsigned int order,
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271 struct zonelist *zonelist, nodemask_t *nodemask);
272
273static inline struct page *
274__alloc_pages(gfp_t gfp_mask, unsigned int order,
275 struct zonelist *zonelist)
276{
d239171e 277 return __alloc_pages_nodemask(gfp_mask, order, zonelist, NULL);
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278}
279
dd0fc66f 280static inline struct page *alloc_pages_node(int nid, gfp_t gfp_mask,
1da177e4
LT
281 unsigned int order)
282{
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283 /* Unknown node is current node */
284 if (nid < 0)
285 nid = numa_node_id();
286
0e88460d 287 return __alloc_pages(gfp_mask, order, node_zonelist(nid, gfp_mask));
1da177e4
LT
288}
289
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290static inline struct page *alloc_pages_exact_node(int nid, gfp_t gfp_mask,
291 unsigned int order)
292{
293 VM_BUG_ON(nid < 0 || nid >= MAX_NUMNODES);
294
295 return __alloc_pages(gfp_mask, order, node_zonelist(nid, gfp_mask));
296}
297
1da177e4 298#ifdef CONFIG_NUMA
dd0fc66f 299extern struct page *alloc_pages_current(gfp_t gfp_mask, unsigned order);
1da177e4
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300
301static inline struct page *
dd0fc66f 302alloc_pages(gfp_t gfp_mask, unsigned int order)
1da177e4 303{
1da177e4
LT
304 return alloc_pages_current(gfp_mask, order);
305}
dd0fc66f 306extern struct page *alloc_page_vma(gfp_t gfp_mask,
1da177e4
LT
307 struct vm_area_struct *vma, unsigned long addr);
308#else
309#define alloc_pages(gfp_mask, order) \
310 alloc_pages_node(numa_node_id(), gfp_mask, order)
311#define alloc_page_vma(gfp_mask, vma, addr) alloc_pages(gfp_mask, 0)
312#endif
313#define alloc_page(gfp_mask) alloc_pages(gfp_mask, 0)
314
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HH
315extern unsigned long __get_free_pages(gfp_t gfp_mask, unsigned int order);
316extern unsigned long get_zeroed_page(gfp_t gfp_mask);
1da177e4 317
2be0ffe2
TT
318void *alloc_pages_exact(size_t size, gfp_t gfp_mask);
319void free_pages_exact(void *virt, size_t size);
320
1da177e4
LT
321#define __get_free_page(gfp_mask) \
322 __get_free_pages((gfp_mask),0)
323
324#define __get_dma_pages(gfp_mask, order) \
325 __get_free_pages((gfp_mask) | GFP_DMA,(order))
326
b3c97528
HH
327extern void __free_pages(struct page *page, unsigned int order);
328extern void free_pages(unsigned long addr, unsigned int order);
fc91668e 329extern void free_hot_cold_page(struct page *page, int cold);
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LT
330
331#define __free_page(page) __free_pages((page), 0)
332#define free_page(addr) free_pages((addr),0)
333
334void page_alloc_init(void);
4037d452 335void drain_zone_pages(struct zone *zone, struct per_cpu_pages *pcp);
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336void drain_all_pages(void);
337void drain_local_pages(void *dummy);
1da177e4 338
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339extern gfp_t gfp_allowed_mask;
340
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RW
341extern void set_gfp_allowed_mask(gfp_t mask);
342extern gfp_t clear_gfp_allowed_mask(gfp_t mask);
dcce284a 343
1da177e4 344#endif /* __LINUX_GFP_H */
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