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