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Linux/include/linux/gfp.h

  1 #ifndef __LINUX_GFP_H
  2 #define __LINUX_GFP_H
  3 
  4 #include <linux/mmdebug.h>
  5 #include <linux/mmzone.h>
  6 #include <linux/stddef.h>
  7 #include <linux/linkage.h>
  8 #include <linux/topology.h>
  9 
 10 struct vm_area_struct;
 11 
 12 /*
 13  * In case of changes, please don't forget to update
 14  * include/trace/events/mmflags.h and tools/perf/builtin-kmem.c
 15  */
 16 
 17 /* Plain integer GFP bitmasks. Do not use this directly. */
 18 #define ___GFP_DMA              0x01u
 19 #define ___GFP_HIGHMEM          0x02u
 20 #define ___GFP_DMA32            0x04u
 21 #define ___GFP_MOVABLE          0x08u
 22 #define ___GFP_RECLAIMABLE      0x10u
 23 #define ___GFP_HIGH             0x20u
 24 #define ___GFP_IO               0x40u
 25 #define ___GFP_FS               0x80u
 26 #define ___GFP_COLD             0x100u
 27 #define ___GFP_NOWARN           0x200u
 28 #define ___GFP_REPEAT           0x400u
 29 #define ___GFP_NOFAIL           0x800u
 30 #define ___GFP_NORETRY          0x1000u
 31 #define ___GFP_MEMALLOC         0x2000u
 32 #define ___GFP_COMP             0x4000u
 33 #define ___GFP_ZERO             0x8000u
 34 #define ___GFP_NOMEMALLOC       0x10000u
 35 #define ___GFP_HARDWALL         0x20000u
 36 #define ___GFP_THISNODE         0x40000u
 37 #define ___GFP_ATOMIC           0x80000u
 38 #define ___GFP_ACCOUNT          0x100000u
 39 #define ___GFP_NOTRACK          0x200000u
 40 #define ___GFP_DIRECT_RECLAIM   0x400000u
 41 #define ___GFP_OTHER_NODE       0x800000u
 42 #define ___GFP_WRITE            0x1000000u
 43 #define ___GFP_KSWAPD_RECLAIM   0x2000000u
 44 /* If the above are modified, __GFP_BITS_SHIFT may need updating */
 45 
 46 /*
 47  * Physical address zone modifiers (see linux/mmzone.h - low four bits)
 48  *
 49  * Do not put any conditional on these. If necessary modify the definitions
 50  * without the underscores and use them consistently. The definitions here may
 51  * be used in bit comparisons.
 52  */
 53 #define __GFP_DMA       ((__force gfp_t)___GFP_DMA)
 54 #define __GFP_HIGHMEM   ((__force gfp_t)___GFP_HIGHMEM)
 55 #define __GFP_DMA32     ((__force gfp_t)___GFP_DMA32)
 56 #define __GFP_MOVABLE   ((__force gfp_t)___GFP_MOVABLE)  /* ZONE_MOVABLE allowed */
 57 #define GFP_ZONEMASK    (__GFP_DMA|__GFP_HIGHMEM|__GFP_DMA32|__GFP_MOVABLE)
 58 
 59 /*
 60  * Page mobility and placement hints
 61  *
 62  * These flags provide hints about how mobile the page is. Pages with similar
 63  * mobility are placed within the same pageblocks to minimise problems due
 64  * to external fragmentation.
 65  *
 66  * __GFP_MOVABLE (also a zone modifier) indicates that the page can be
 67  *   moved by page migration during memory compaction or can be reclaimed.
 68  *
 69  * __GFP_RECLAIMABLE is used for slab allocations that specify
 70  *   SLAB_RECLAIM_ACCOUNT and whose pages can be freed via shrinkers.
 71  *
 72  * __GFP_WRITE indicates the caller intends to dirty the page. Where possible,
 73  *   these pages will be spread between local zones to avoid all the dirty
 74  *   pages being in one zone (fair zone allocation policy).
 75  *
 76  * __GFP_HARDWALL enforces the cpuset memory allocation policy.
 77  *
 78  * __GFP_THISNODE forces the allocation to be satisified from the requested
 79  *   node with no fallbacks or placement policy enforcements.
 80  *
 81  * __GFP_ACCOUNT causes the allocation to be accounted to kmemcg (only relevant
 82  *   to kmem allocations).
 83  */
 84 #define __GFP_RECLAIMABLE ((__force gfp_t)___GFP_RECLAIMABLE)
 85 #define __GFP_WRITE     ((__force gfp_t)___GFP_WRITE)
 86 #define __GFP_HARDWALL   ((__force gfp_t)___GFP_HARDWALL)
 87 #define __GFP_THISNODE  ((__force gfp_t)___GFP_THISNODE)
 88 #define __GFP_ACCOUNT   ((__force gfp_t)___GFP_ACCOUNT)
 89 
 90 /*
 91  * Watermark modifiers -- controls access to emergency reserves
 92  *
 93  * __GFP_HIGH indicates that the caller is high-priority and that granting
 94  *   the request is necessary before the system can make forward progress.
 95  *   For example, creating an IO context to clean pages.
 96  *
 97  * __GFP_ATOMIC indicates that the caller cannot reclaim or sleep and is
 98  *   high priority. Users are typically interrupt handlers. This may be
 99  *   used in conjunction with __GFP_HIGH
100  *
101  * __GFP_MEMALLOC allows access to all memory. This should only be used when
102  *   the caller guarantees the allocation will allow more memory to be freed
103  *   very shortly e.g. process exiting or swapping. Users either should
104  *   be the MM or co-ordinating closely with the VM (e.g. swap over NFS).
105  *
106  * __GFP_NOMEMALLOC is used to explicitly forbid access to emergency reserves.
107  *   This takes precedence over the __GFP_MEMALLOC flag if both are set.
108  */
109 #define __GFP_ATOMIC    ((__force gfp_t)___GFP_ATOMIC)
110 #define __GFP_HIGH      ((__force gfp_t)___GFP_HIGH)
111 #define __GFP_MEMALLOC  ((__force gfp_t)___GFP_MEMALLOC)
112 #define __GFP_NOMEMALLOC ((__force gfp_t)___GFP_NOMEMALLOC)
113 
114 /*
115  * Reclaim modifiers
116  *
117  * __GFP_IO can start physical IO.
118  *
119  * __GFP_FS can call down to the low-level FS. Clearing the flag avoids the
120  *   allocator recursing into the filesystem which might already be holding
121  *   locks.
122  *
123  * __GFP_DIRECT_RECLAIM indicates that the caller may enter direct reclaim.
124  *   This flag can be cleared to avoid unnecessary delays when a fallback
125  *   option is available.
126  *
127  * __GFP_KSWAPD_RECLAIM indicates that the caller wants to wake kswapd when
128  *   the low watermark is reached and have it reclaim pages until the high
129  *   watermark is reached. A caller may wish to clear this flag when fallback
130  *   options are available and the reclaim is likely to disrupt the system. The
131  *   canonical example is THP allocation where a fallback is cheap but
132  *   reclaim/compaction may cause indirect stalls.
133  *
134  * __GFP_RECLAIM is shorthand to allow/forbid both direct and kswapd reclaim.
135  *
136  * __GFP_REPEAT: Try hard to allocate the memory, but the allocation attempt
137  *   _might_ fail.  This depends upon the particular VM implementation.
138  *
139  * __GFP_NOFAIL: The VM implementation _must_ retry infinitely: the caller
140  *   cannot handle allocation failures. New users should be evaluated carefully
141  *   (and the flag should be used only when there is no reasonable failure
142  *   policy) but it is definitely preferable to use the flag rather than
143  *   opencode endless loop around allocator.
144  *
145  * __GFP_NORETRY: The VM implementation must not retry indefinitely and will
146  *   return NULL when direct reclaim and memory compaction have failed to allow
147  *   the allocation to succeed.  The OOM killer is not called with the current
148  *   implementation.
149  */
150 #define __GFP_IO        ((__force gfp_t)___GFP_IO)
151 #define __GFP_FS        ((__force gfp_t)___GFP_FS)
152 #define __GFP_DIRECT_RECLAIM    ((__force gfp_t)___GFP_DIRECT_RECLAIM) /* Caller can reclaim */
153 #define __GFP_KSWAPD_RECLAIM    ((__force gfp_t)___GFP_KSWAPD_RECLAIM) /* kswapd can wake */
154 #define __GFP_RECLAIM ((__force gfp_t)(___GFP_DIRECT_RECLAIM|___GFP_KSWAPD_RECLAIM))
155 #define __GFP_REPEAT    ((__force gfp_t)___GFP_REPEAT)
156 #define __GFP_NOFAIL    ((__force gfp_t)___GFP_NOFAIL)
157 #define __GFP_NORETRY   ((__force gfp_t)___GFP_NORETRY)
158 
159 /*
160  * Action modifiers
161  *
162  * __GFP_COLD indicates that the caller does not expect to be used in the near
163  *   future. Where possible, a cache-cold page will be returned.
164  *
165  * __GFP_NOWARN suppresses allocation failure reports.
166  *
167  * __GFP_COMP address compound page metadata.
168  *
169  * __GFP_ZERO returns a zeroed page on success.
170  *
171  * __GFP_NOTRACK avoids tracking with kmemcheck.
172  *
173  * __GFP_NOTRACK_FALSE_POSITIVE is an alias of __GFP_NOTRACK. It's a means of
174  *   distinguishing in the source between false positives and allocations that
175  *   cannot be supported (e.g. page tables).
176  *
177  * __GFP_OTHER_NODE is for allocations that are on a remote node but that
178  *   should not be accounted for as a remote allocation in vmstat. A
179  *   typical user would be khugepaged collapsing a huge page on a remote
180  *   node.
181  */
182 #define __GFP_COLD      ((__force gfp_t)___GFP_COLD)
183 #define __GFP_NOWARN    ((__force gfp_t)___GFP_NOWARN)
184 #define __GFP_COMP      ((__force gfp_t)___GFP_COMP)
185 #define __GFP_ZERO      ((__force gfp_t)___GFP_ZERO)
186 #define __GFP_NOTRACK   ((__force gfp_t)___GFP_NOTRACK)
187 #define __GFP_NOTRACK_FALSE_POSITIVE (__GFP_NOTRACK)
188 #define __GFP_OTHER_NODE ((__force gfp_t)___GFP_OTHER_NODE)
189 
190 /* Room for N __GFP_FOO bits */
191 #define __GFP_BITS_SHIFT 26
192 #define __GFP_BITS_MASK ((__force gfp_t)((1 << __GFP_BITS_SHIFT) - 1))
193 
194 /*
195  * Useful GFP flag combinations that are commonly used. It is recommended
196  * that subsystems start with one of these combinations and then set/clear
197  * __GFP_FOO flags as necessary.
198  *
199  * GFP_ATOMIC users can not sleep and need the allocation to succeed. A lower
200  *   watermark is applied to allow access to "atomic reserves"
201  *
202  * GFP_KERNEL is typical for kernel-internal allocations. The caller requires
203  *   ZONE_NORMAL or a lower zone for direct access but can direct reclaim.
204  *
205  * GFP_KERNEL_ACCOUNT is the same as GFP_KERNEL, except the allocation is
206  *   accounted to kmemcg.
207  *
208  * GFP_NOWAIT is for kernel allocations that should not stall for direct
209  *   reclaim, start physical IO or use any filesystem callback.
210  *
211  * GFP_NOIO will use direct reclaim to discard clean pages or slab pages
212  *   that do not require the starting of any physical IO.
213  *
214  * GFP_NOFS will use direct reclaim but will not use any filesystem interfaces.
215  *
216  * GFP_USER is for userspace allocations that also need to be directly
217  *   accessibly by the kernel or hardware. It is typically used by hardware
218  *   for buffers that are mapped to userspace (e.g. graphics) that hardware
219  *   still must DMA to. cpuset limits are enforced for these allocations.
220  *
221  * GFP_DMA exists for historical reasons and should be avoided where possible.
222  *   The flags indicates that the caller requires that the lowest zone be
223  *   used (ZONE_DMA or 16M on x86-64). Ideally, this would be removed but
224  *   it would require careful auditing as some users really require it and
225  *   others use the flag to avoid lowmem reserves in ZONE_DMA and treat the
226  *   lowest zone as a type of emergency reserve.
227  *
228  * GFP_DMA32 is similar to GFP_DMA except that the caller requires a 32-bit
229  *   address.
230  *
231  * GFP_HIGHUSER is for userspace allocations that may be mapped to userspace,
232  *   do not need to be directly accessible by the kernel but that cannot
233  *   move once in use. An example may be a hardware allocation that maps
234  *   data directly into userspace but has no addressing limitations.
235  *
236  * GFP_HIGHUSER_MOVABLE is for userspace allocations that the kernel does not
237  *   need direct access to but can use kmap() when access is required. They
238  *   are expected to be movable via page reclaim or page migration. Typically,
239  *   pages on the LRU would also be allocated with GFP_HIGHUSER_MOVABLE.
240  *
241  * GFP_TRANSHUGE is used for THP allocations. They are compound allocations
242  *   that will fail quickly if memory is not available and will not wake
243  *   kswapd on failure.
244  */
245 #define GFP_ATOMIC      (__GFP_HIGH|__GFP_ATOMIC|__GFP_KSWAPD_RECLAIM)
246 #define GFP_KERNEL      (__GFP_RECLAIM | __GFP_IO | __GFP_FS)
247 #define GFP_KERNEL_ACCOUNT (GFP_KERNEL | __GFP_ACCOUNT)
248 #define GFP_NOWAIT      (__GFP_KSWAPD_RECLAIM)
249 #define GFP_NOIO        (__GFP_RECLAIM)
250 #define GFP_NOFS        (__GFP_RECLAIM | __GFP_IO)
251 #define GFP_TEMPORARY   (__GFP_RECLAIM | __GFP_IO | __GFP_FS | \
252                          __GFP_RECLAIMABLE)
253 #define GFP_USER        (__GFP_RECLAIM | __GFP_IO | __GFP_FS | __GFP_HARDWALL)
254 #define GFP_DMA         __GFP_DMA
255 #define GFP_DMA32       __GFP_DMA32
256 #define GFP_HIGHUSER    (GFP_USER | __GFP_HIGHMEM)
257 #define GFP_HIGHUSER_MOVABLE    (GFP_HIGHUSER | __GFP_MOVABLE)
258 #define GFP_TRANSHUGE   ((GFP_HIGHUSER_MOVABLE | __GFP_COMP | \
259                          __GFP_NOMEMALLOC | __GFP_NORETRY | __GFP_NOWARN) & \
260                          ~__GFP_RECLAIM)
261 
262 /* Convert GFP flags to their corresponding migrate type */
263 #define GFP_MOVABLE_MASK (__GFP_RECLAIMABLE|__GFP_MOVABLE)
264 #define GFP_MOVABLE_SHIFT 3
265 
266 static inline int gfpflags_to_migratetype(const gfp_t gfp_flags)
267 {
268         VM_WARN_ON((gfp_flags & GFP_MOVABLE_MASK) == GFP_MOVABLE_MASK);
269         BUILD_BUG_ON((1UL << GFP_MOVABLE_SHIFT) != ___GFP_MOVABLE);
270         BUILD_BUG_ON((___GFP_MOVABLE >> GFP_MOVABLE_SHIFT) != MIGRATE_MOVABLE);
271 
272         if (unlikely(page_group_by_mobility_disabled))
273                 return MIGRATE_UNMOVABLE;
274 
275         /* Group based on mobility */
276         return (gfp_flags & GFP_MOVABLE_MASK) >> GFP_MOVABLE_SHIFT;
277 }
278 #undef GFP_MOVABLE_MASK
279 #undef GFP_MOVABLE_SHIFT
280 
281 static inline bool gfpflags_allow_blocking(const gfp_t gfp_flags)
282 {
283         return !!(gfp_flags & __GFP_DIRECT_RECLAIM);
284 }
285 
286 #ifdef CONFIG_HIGHMEM
287 #define OPT_ZONE_HIGHMEM ZONE_HIGHMEM
288 #else
289 #define OPT_ZONE_HIGHMEM ZONE_NORMAL
290 #endif
291 
292 #ifdef CONFIG_ZONE_DMA
293 #define OPT_ZONE_DMA ZONE_DMA
294 #else
295 #define OPT_ZONE_DMA ZONE_NORMAL
296 #endif
297 
298 #ifdef CONFIG_ZONE_DMA32
299 #define OPT_ZONE_DMA32 ZONE_DMA32
300 #else
301 #define OPT_ZONE_DMA32 ZONE_NORMAL
302 #endif
303 
304 /*
305  * GFP_ZONE_TABLE is a word size bitstring that is used for looking up the
306  * zone to use given the lowest 4 bits of gfp_t. Entries are ZONE_SHIFT long
307  * and there are 16 of them to cover all possible combinations of
308  * __GFP_DMA, __GFP_DMA32, __GFP_MOVABLE and __GFP_HIGHMEM.
309  *
310  * The zone fallback order is MOVABLE=>HIGHMEM=>NORMAL=>DMA32=>DMA.
311  * But GFP_MOVABLE is not only a zone specifier but also an allocation
312  * policy. Therefore __GFP_MOVABLE plus another zone selector is valid.
313  * Only 1 bit of the lowest 3 bits (DMA,DMA32,HIGHMEM) can be set to "1".
314  *
315  *       bit       result
316  *       =================
317  *       0x0    => NORMAL
318  *       0x1    => DMA or NORMAL
319  *       0x2    => HIGHMEM or NORMAL
320  *       0x3    => BAD (DMA+HIGHMEM)
321  *       0x4    => DMA32 or DMA or NORMAL
322  *       0x5    => BAD (DMA+DMA32)
323  *       0x6    => BAD (HIGHMEM+DMA32)
324  *       0x7    => BAD (HIGHMEM+DMA32+DMA)
325  *       0x8    => NORMAL (MOVABLE+0)
326  *       0x9    => DMA or NORMAL (MOVABLE+DMA)
327  *       0xa    => MOVABLE (Movable is valid only if HIGHMEM is set too)
328  *       0xb    => BAD (MOVABLE+HIGHMEM+DMA)
329  *       0xc    => DMA32 (MOVABLE+DMA32)
330  *       0xd    => BAD (MOVABLE+DMA32+DMA)
331  *       0xe    => BAD (MOVABLE+DMA32+HIGHMEM)
332  *       0xf    => BAD (MOVABLE+DMA32+HIGHMEM+DMA)
333  *
334  * GFP_ZONES_SHIFT must be <= 2 on 32 bit platforms.
335  */
336 
337 #if defined(CONFIG_ZONE_DEVICE) && (MAX_NR_ZONES-1) <= 4
338 /* ZONE_DEVICE is not a valid GFP zone specifier */
339 #define GFP_ZONES_SHIFT 2
340 #else
341 #define GFP_ZONES_SHIFT ZONES_SHIFT
342 #endif
343 
344 #if 16 * GFP_ZONES_SHIFT > BITS_PER_LONG
345 #error GFP_ZONES_SHIFT too large to create GFP_ZONE_TABLE integer
346 #endif
347 
348 #define GFP_ZONE_TABLE ( \
349         (ZONE_NORMAL << 0 * GFP_ZONES_SHIFT)                                   \
350         | (OPT_ZONE_DMA << ___GFP_DMA * GFP_ZONES_SHIFT)                       \
351         | (OPT_ZONE_HIGHMEM << ___GFP_HIGHMEM * GFP_ZONES_SHIFT)               \
352         | (OPT_ZONE_DMA32 << ___GFP_DMA32 * GFP_ZONES_SHIFT)                   \
353         | (ZONE_NORMAL << ___GFP_MOVABLE * GFP_ZONES_SHIFT)                    \
354         | (OPT_ZONE_DMA << (___GFP_MOVABLE | ___GFP_DMA) * GFP_ZONES_SHIFT)    \
355         | (ZONE_MOVABLE << (___GFP_MOVABLE | ___GFP_HIGHMEM) * GFP_ZONES_SHIFT)\
356         | (OPT_ZONE_DMA32 << (___GFP_MOVABLE | ___GFP_DMA32) * GFP_ZONES_SHIFT)\
357 )
358 
359 /*
360  * GFP_ZONE_BAD is a bitmap for all combinations of __GFP_DMA, __GFP_DMA32
361  * __GFP_HIGHMEM and __GFP_MOVABLE that are not permitted. One flag per
362  * entry starting with bit 0. Bit is set if the combination is not
363  * allowed.
364  */
365 #define GFP_ZONE_BAD ( \
366         1 << (___GFP_DMA | ___GFP_HIGHMEM)                                    \
367         | 1 << (___GFP_DMA | ___GFP_DMA32)                                    \
368         | 1 << (___GFP_DMA32 | ___GFP_HIGHMEM)                                \
369         | 1 << (___GFP_DMA | ___GFP_DMA32 | ___GFP_HIGHMEM)                   \
370         | 1 << (___GFP_MOVABLE | ___GFP_HIGHMEM | ___GFP_DMA)                 \
371         | 1 << (___GFP_MOVABLE | ___GFP_DMA32 | ___GFP_DMA)                   \
372         | 1 << (___GFP_MOVABLE | ___GFP_DMA32 | ___GFP_HIGHMEM)               \
373         | 1 << (___GFP_MOVABLE | ___GFP_DMA32 | ___GFP_DMA | ___GFP_HIGHMEM)  \
374 )
375 
376 static inline enum zone_type gfp_zone(gfp_t flags)
377 {
378         enum zone_type z;
379         int bit = (__force int) (flags & GFP_ZONEMASK);
380 
381         z = (GFP_ZONE_TABLE >> (bit * GFP_ZONES_SHIFT)) &
382                                          ((1 << GFP_ZONES_SHIFT) - 1);
383         VM_BUG_ON((GFP_ZONE_BAD >> bit) & 1);
384         return z;
385 }
386 
387 /*
388  * There is only one page-allocator function, and two main namespaces to
389  * it. The alloc_page*() variants return 'struct page *' and as such
390  * can allocate highmem pages, the *get*page*() variants return
391  * virtual kernel addresses to the allocated page(s).
392  */
393 
394 static inline int gfp_zonelist(gfp_t flags)
395 {
396 #ifdef CONFIG_NUMA
397         if (unlikely(flags & __GFP_THISNODE))
398                 return ZONELIST_NOFALLBACK;
399 #endif
400         return ZONELIST_FALLBACK;
401 }
402 
403 /*
404  * We get the zone list from the current node and the gfp_mask.
405  * This zone list contains a maximum of MAXNODES*MAX_NR_ZONES zones.
406  * There are two zonelists per node, one for all zones with memory and
407  * one containing just zones from the node the zonelist belongs to.
408  *
409  * For the normal case of non-DISCONTIGMEM systems the NODE_DATA() gets
410  * optimized to &contig_page_data at compile-time.
411  */
412 static inline struct zonelist *node_zonelist(int nid, gfp_t flags)
413 {
414         return NODE_DATA(nid)->node_zonelists + gfp_zonelist(flags);
415 }
416 
417 #ifndef HAVE_ARCH_FREE_PAGE
418 static inline void arch_free_page(struct page *page, int order) { }
419 #endif
420 #ifndef HAVE_ARCH_ALLOC_PAGE
421 static inline void arch_alloc_page(struct page *page, int order) { }
422 #endif
423 
424 struct page *
425 __alloc_pages_nodemask(gfp_t gfp_mask, unsigned int order,
426                        struct zonelist *zonelist, nodemask_t *nodemask);
427 
428 static inline struct page *
429 __alloc_pages(gfp_t gfp_mask, unsigned int order,
430                 struct zonelist *zonelist)
431 {
432         return __alloc_pages_nodemask(gfp_mask, order, zonelist, NULL);
433 }
434 
435 /*
436  * Allocate pages, preferring the node given as nid. The node must be valid and
437  * online. For more general interface, see alloc_pages_node().
438  */
439 static inline struct page *
440 __alloc_pages_node(int nid, gfp_t gfp_mask, unsigned int order)
441 {
442         VM_BUG_ON(nid < 0 || nid >= MAX_NUMNODES);
443         VM_WARN_ON(!node_online(nid));
444 
445         return __alloc_pages(gfp_mask, order, node_zonelist(nid, gfp_mask));
446 }
447 
448 /*
449  * Allocate pages, preferring the node given as nid. When nid == NUMA_NO_NODE,
450  * prefer the current CPU's closest node. Otherwise node must be valid and
451  * online.
452  */
453 static inline struct page *alloc_pages_node(int nid, gfp_t gfp_mask,
454                                                 unsigned int order)
455 {
456         if (nid == NUMA_NO_NODE)
457                 nid = numa_mem_id();
458 
459         return __alloc_pages_node(nid, gfp_mask, order);
460 }
461 
462 #ifdef CONFIG_NUMA
463 extern struct page *alloc_pages_current(gfp_t gfp_mask, unsigned order);
464 
465 static inline struct page *
466 alloc_pages(gfp_t gfp_mask, unsigned int order)
467 {
468         return alloc_pages_current(gfp_mask, order);
469 }
470 extern struct page *alloc_pages_vma(gfp_t gfp_mask, int order,
471                         struct vm_area_struct *vma, unsigned long addr,
472                         int node, bool hugepage);
473 #define alloc_hugepage_vma(gfp_mask, vma, addr, order)  \
474         alloc_pages_vma(gfp_mask, order, vma, addr, numa_node_id(), true)
475 #else
476 #define alloc_pages(gfp_mask, order) \
477                 alloc_pages_node(numa_node_id(), gfp_mask, order)
478 #define alloc_pages_vma(gfp_mask, order, vma, addr, node, false)\
479         alloc_pages(gfp_mask, order)
480 #define alloc_hugepage_vma(gfp_mask, vma, addr, order)  \
481         alloc_pages(gfp_mask, order)
482 #endif
483 #define alloc_page(gfp_mask) alloc_pages(gfp_mask, 0)
484 #define alloc_page_vma(gfp_mask, vma, addr)                     \
485         alloc_pages_vma(gfp_mask, 0, vma, addr, numa_node_id(), false)
486 #define alloc_page_vma_node(gfp_mask, vma, addr, node)          \
487         alloc_pages_vma(gfp_mask, 0, vma, addr, node, false)
488 
489 extern struct page *alloc_kmem_pages(gfp_t gfp_mask, unsigned int order);
490 extern struct page *alloc_kmem_pages_node(int nid, gfp_t gfp_mask,
491                                           unsigned int order);
492 
493 extern unsigned long __get_free_pages(gfp_t gfp_mask, unsigned int order);
494 extern unsigned long get_zeroed_page(gfp_t gfp_mask);
495 
496 void *alloc_pages_exact(size_t size, gfp_t gfp_mask);
497 void free_pages_exact(void *virt, size_t size);
498 void * __meminit alloc_pages_exact_nid(int nid, size_t size, gfp_t gfp_mask);
499 
500 #define __get_free_page(gfp_mask) \
501                 __get_free_pages((gfp_mask), 0)
502 
503 #define __get_dma_pages(gfp_mask, order) \
504                 __get_free_pages((gfp_mask) | GFP_DMA, (order))
505 
506 extern void __free_pages(struct page *page, unsigned int order);
507 extern void free_pages(unsigned long addr, unsigned int order);
508 extern void free_hot_cold_page(struct page *page, bool cold);
509 extern void free_hot_cold_page_list(struct list_head *list, bool cold);
510 
511 struct page_frag_cache;
512 extern void *__alloc_page_frag(struct page_frag_cache *nc,
513                                unsigned int fragsz, gfp_t gfp_mask);
514 extern void __free_page_frag(void *addr);
515 
516 extern void __free_kmem_pages(struct page *page, unsigned int order);
517 extern void free_kmem_pages(unsigned long addr, unsigned int order);
518 
519 #define __free_page(page) __free_pages((page), 0)
520 #define free_page(addr) free_pages((addr), 0)
521 
522 void page_alloc_init(void);
523 void drain_zone_pages(struct zone *zone, struct per_cpu_pages *pcp);
524 void drain_all_pages(struct zone *zone);
525 void drain_local_pages(struct zone *zone);
526 
527 void page_alloc_init_late(void);
528 
529 /*
530  * gfp_allowed_mask is set to GFP_BOOT_MASK during early boot to restrict what
531  * GFP flags are used before interrupts are enabled. Once interrupts are
532  * enabled, it is set to __GFP_BITS_MASK while the system is running. During
533  * hibernation, it is used by PM to avoid I/O during memory allocation while
534  * devices are suspended.
535  */
536 extern gfp_t gfp_allowed_mask;
537 
538 /* Returns true if the gfp_mask allows use of ALLOC_NO_WATERMARK */
539 bool gfp_pfmemalloc_allowed(gfp_t gfp_mask);
540 
541 extern void pm_restrict_gfp_mask(void);
542 extern void pm_restore_gfp_mask(void);
543 
544 #ifdef CONFIG_PM_SLEEP
545 extern bool pm_suspended_storage(void);
546 #else
547 static inline bool pm_suspended_storage(void)
548 {
549         return false;
550 }
551 #endif /* CONFIG_PM_SLEEP */
552 
553 #if (defined(CONFIG_MEMORY_ISOLATION) && defined(CONFIG_COMPACTION)) || defined(CONFIG_CMA)
554 /* The below functions must be run on a range from a single zone. */
555 extern int alloc_contig_range(unsigned long start, unsigned long end,
556                               unsigned migratetype);
557 extern void free_contig_range(unsigned long pfn, unsigned nr_pages);
558 #endif
559 
560 #ifdef CONFIG_CMA
561 /* CMA stuff */
562 extern void init_cma_reserved_pageblock(struct page *page);
563 #endif
564 
565 #endif /* __LINUX_GFP_H */
566 

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