1 #ifndef _LINUX_MMZONE_H
2 #define _LINUX_MMZONE_H
7 #include <linux/spinlock.h>
8 #include <linux/list.h>
9 #include <linux/wait.h>
10 #include <linux/cache.h>
11 #include <linux/threads.h>
12 #include <linux/numa.h>
13 #include <linux/init.h>
14 #include <linux/seqlock.h>
15 #include <linux/nodemask.h>
16 #include <asm/atomic.h>
19 /* Free memory management - zoned buddy allocator. */
20 #ifndef CONFIG_FORCE_MAX_ZONEORDER
23 #define MAX_ORDER CONFIG_FORCE_MAX_ZONEORDER
25 #define MAX_ORDER_NR_PAGES (1 << (MAX_ORDER - 1))
28 struct list_head free_list
;
29 unsigned long nr_free
;
35 * zone->lock and zone->lru_lock are two of the hottest locks in the kernel.
36 * So add a wild amount of padding here to ensure that they fall into separate
37 * cachelines. There are very few zone structures in the machine, so space
38 * consumption is not a concern here.
40 #if defined(CONFIG_SMP)
43 } ____cacheline_internodealigned_in_smp
;
44 #define ZONE_PADDING(name) struct zone_padding name;
46 #define ZONE_PADDING(name)
50 /* First 128 byte cacheline (assuming 64 bit words) */
54 NR_ANON_PAGES
, /* Mapped anonymous pages */
55 NR_FILE_MAPPED
, /* pagecache pages mapped into pagetables.
56 only modified from process context */
60 /* Second 128 byte cacheline */
62 NR_SLAB_UNRECLAIMABLE
,
63 NR_PAGETABLE
, /* used for pagetables */
64 NR_UNSTABLE_NFS
, /* NFS unstable pages */
68 NUMA_HIT
, /* allocated in intended node */
69 NUMA_MISS
, /* allocated in non intended node */
70 NUMA_FOREIGN
, /* was intended here, hit elsewhere */
71 NUMA_INTERLEAVE_HIT
, /* interleaver preferred this zone */
72 NUMA_LOCAL
, /* allocation from local node */
73 NUMA_OTHER
, /* allocation from other node */
75 NR_VM_ZONE_STAT_ITEMS
};
77 struct per_cpu_pages
{
78 int count
; /* number of pages in the list */
79 int high
; /* high watermark, emptying needed */
80 int batch
; /* chunk size for buddy add/remove */
81 struct list_head list
; /* the list of pages */
84 struct per_cpu_pageset
{
85 struct per_cpu_pages pcp
[2]; /* 0: hot. 1: cold */
88 s8 vm_stat_diff
[NR_VM_ZONE_STAT_ITEMS
];
90 } ____cacheline_aligned_in_smp
;
93 #define zone_pcp(__z, __cpu) ((__z)->pageset[(__cpu)])
95 #define zone_pcp(__z, __cpu) (&(__z)->pageset[(__cpu)])
100 * ZONE_DMA is used when there are devices that are not able
101 * to do DMA to all of addressable memory (ZONE_NORMAL). Then we
102 * carve out the portion of memory that is needed for these devices.
103 * The range is arch specific.
108 * ---------------------------
109 * parisc, ia64, sparc <4G
113 * alpha Unlimited or 0-16MB.
115 * i386, x86_64 and multiple other arches
119 #ifdef CONFIG_ZONE_DMA32
121 * x86_64 needs two ZONE_DMAs because it supports devices that are
122 * only able to do DMA to the lower 16M but also 32 bit devices that
123 * can only do DMA areas below 4G.
128 * Normal addressable memory is in ZONE_NORMAL. DMA operations can be
129 * performed on pages in ZONE_NORMAL if the DMA devices support
130 * transfers to all addressable memory.
133 #ifdef CONFIG_HIGHMEM
135 * A memory area that is only addressable by the kernel through
136 * mapping portions into its own address space. This is for example
137 * used by i386 to allow the kernel to address the memory beyond
138 * 900MB. The kernel will set up special mappings (page
139 * table entries on i386) for each page that the kernel needs to
148 * When a memory allocation must conform to specific limitations (such
149 * as being suitable for DMA) the caller will pass in hints to the
150 * allocator in the gfp_mask, in the zone modifier bits. These bits
151 * are used to select a priority ordered list of memory zones which
152 * match the requested limits. See gfp_zone() in include/linux/gfp.h
155 #if !defined(CONFIG_ZONE_DMA32) && !defined(CONFIG_HIGHMEM)
156 #define ZONES_SHIFT 1
158 #define ZONES_SHIFT 2
162 /* Fields commonly accessed by the page allocator */
163 unsigned long pages_min
, pages_low
, pages_high
;
165 * We don't know if the memory that we're going to allocate will be freeable
166 * or/and it will be released eventually, so to avoid totally wasting several
167 * GB of ram we must reserve some of the lower zone memory (otherwise we risk
168 * to run OOM on the lower zones despite there's tons of freeable ram
169 * on the higher zones). This array is recalculated at runtime if the
170 * sysctl_lowmem_reserve_ratio sysctl changes.
172 unsigned long lowmem_reserve
[MAX_NR_ZONES
];
177 * zone reclaim becomes active if more unmapped pages exist.
179 unsigned long min_unmapped_pages
;
180 unsigned long min_slab_pages
;
181 struct per_cpu_pageset
*pageset
[NR_CPUS
];
183 struct per_cpu_pageset pageset
[NR_CPUS
];
186 * free areas of different sizes
189 #ifdef CONFIG_MEMORY_HOTPLUG
190 /* see spanned/present_pages for more description */
191 seqlock_t span_seqlock
;
193 struct free_area free_area
[MAX_ORDER
];
198 /* Fields commonly accessed by the page reclaim scanner */
200 struct list_head active_list
;
201 struct list_head inactive_list
;
202 unsigned long nr_scan_active
;
203 unsigned long nr_scan_inactive
;
204 unsigned long pages_scanned
; /* since last reclaim */
205 int all_unreclaimable
; /* All pages pinned */
207 /* A count of how many reclaimers are scanning this zone */
208 atomic_t reclaim_in_progress
;
210 /* Zone statistics */
211 atomic_long_t vm_stat
[NR_VM_ZONE_STAT_ITEMS
];
214 * prev_priority holds the scanning priority for this zone. It is
215 * defined as the scanning priority at which we achieved our reclaim
216 * target at the previous try_to_free_pages() or balance_pgdat()
219 * We use prev_priority as a measure of how much stress page reclaim is
220 * under - it drives the swappiness decision: whether to unmap mapped
223 * Access to both this field is quite racy even on uniprocessor. But
224 * it is expected to average out OK.
230 /* Rarely used or read-mostly fields */
233 * wait_table -- the array holding the hash table
234 * wait_table_hash_nr_entries -- the size of the hash table array
235 * wait_table_bits -- wait_table_size == (1 << wait_table_bits)
237 * The purpose of all these is to keep track of the people
238 * waiting for a page to become available and make them
239 * runnable again when possible. The trouble is that this
240 * consumes a lot of space, especially when so few things
241 * wait on pages at a given time. So instead of using
242 * per-page waitqueues, we use a waitqueue hash table.
244 * The bucket discipline is to sleep on the same queue when
245 * colliding and wake all in that wait queue when removing.
246 * When something wakes, it must check to be sure its page is
247 * truly available, a la thundering herd. The cost of a
248 * collision is great, but given the expected load of the
249 * table, they should be so rare as to be outweighed by the
250 * benefits from the saved space.
252 * __wait_on_page_locked() and unlock_page() in mm/filemap.c, are the
253 * primary users of these fields, and in mm/page_alloc.c
254 * free_area_init_core() performs the initialization of them.
256 wait_queue_head_t
* wait_table
;
257 unsigned long wait_table_hash_nr_entries
;
258 unsigned long wait_table_bits
;
261 * Discontig memory support fields.
263 struct pglist_data
*zone_pgdat
;
264 /* zone_start_pfn == zone_start_paddr >> PAGE_SHIFT */
265 unsigned long zone_start_pfn
;
268 * zone_start_pfn, spanned_pages and present_pages are all
269 * protected by span_seqlock. It is a seqlock because it has
270 * to be read outside of zone->lock, and it is done in the main
271 * allocator path. But, it is written quite infrequently.
273 * The lock is declared along with zone->lock because it is
274 * frequently read in proximity to zone->lock. It's good to
275 * give them a chance of being in the same cacheline.
277 unsigned long spanned_pages
; /* total size, including holes */
278 unsigned long present_pages
; /* amount of memory (excluding holes) */
281 * rarely used fields:
284 } ____cacheline_internodealigned_in_smp
;
287 * The "priority" of VM scanning is how much of the queues we will scan in one
288 * go. A value of 12 for DEF_PRIORITY implies that we will scan 1/4096th of the
289 * queues ("queue_length >> 12") during an aging round.
291 #define DEF_PRIORITY 12
293 /* Maximum number of zones on a zonelist */
294 #define MAX_ZONES_PER_ZONELIST (MAX_NUMNODES * MAX_NR_ZONES)
298 * We cache key information from each zonelist for smaller cache
299 * footprint when scanning for free pages in get_page_from_freelist().
301 * 1) The BITMAP fullzones tracks which zones in a zonelist have come
302 * up short of free memory since the last time (last_fullzone_zap)
303 * we zero'd fullzones.
304 * 2) The array z_to_n[] maps each zone in the zonelist to its node
305 * id, so that we can efficiently evaluate whether that node is
306 * set in the current tasks mems_allowed.
308 * Both fullzones and z_to_n[] are one-to-one with the zonelist,
309 * indexed by a zones offset in the zonelist zones[] array.
311 * The get_page_from_freelist() routine does two scans. During the
312 * first scan, we skip zones whose corresponding bit in 'fullzones'
313 * is set or whose corresponding node in current->mems_allowed (which
314 * comes from cpusets) is not set. During the second scan, we bypass
315 * this zonelist_cache, to ensure we look methodically at each zone.
317 * Once per second, we zero out (zap) fullzones, forcing us to
318 * reconsider nodes that might have regained more free memory.
319 * The field last_full_zap is the time we last zapped fullzones.
321 * This mechanism reduces the amount of time we waste repeatedly
322 * reexaming zones for free memory when they just came up low on
323 * memory momentarilly ago.
325 * The zonelist_cache struct members logically belong in struct
326 * zonelist. However, the mempolicy zonelists constructed for
327 * MPOL_BIND are intentionally variable length (and usually much
328 * shorter). A general purpose mechanism for handling structs with
329 * multiple variable length members is more mechanism than we want
330 * here. We resort to some special case hackery instead.
332 * The MPOL_BIND zonelists don't need this zonelist_cache (in good
333 * part because they are shorter), so we put the fixed length stuff
334 * at the front of the zonelist struct, ending in a variable length
335 * zones[], as is needed by MPOL_BIND.
337 * Then we put the optional zonelist cache on the end of the zonelist
338 * struct. This optional stuff is found by a 'zlcache_ptr' pointer in
339 * the fixed length portion at the front of the struct. This pointer
340 * both enables us to find the zonelist cache, and in the case of
341 * MPOL_BIND zonelists, (which will just set the zlcache_ptr to NULL)
342 * to know that the zonelist cache is not there.
344 * The end result is that struct zonelists come in two flavors:
345 * 1) The full, fixed length version, shown below, and
346 * 2) The custom zonelists for MPOL_BIND.
347 * The custom MPOL_BIND zonelists have a NULL zlcache_ptr and no zlcache.
349 * Even though there may be multiple CPU cores on a node modifying
350 * fullzones or last_full_zap in the same zonelist_cache at the same
351 * time, we don't lock it. This is just hint data - if it is wrong now
352 * and then, the allocator will still function, perhaps a bit slower.
356 struct zonelist_cache
{
357 unsigned short z_to_n
[MAX_ZONES_PER_ZONELIST
]; /* zone->nid */
358 DECLARE_BITMAP(fullzones
, MAX_ZONES_PER_ZONELIST
); /* zone full? */
359 unsigned long last_full_zap
; /* when last zap'd (jiffies) */
362 struct zonelist_cache
;
366 * One allocation request operates on a zonelist. A zonelist
367 * is a list of zones, the first one is the 'goal' of the
368 * allocation, the other zones are fallback zones, in decreasing
371 * If zlcache_ptr is not NULL, then it is just the address of zlcache,
372 * as explained above. If zlcache_ptr is NULL, there is no zlcache.
376 struct zonelist_cache
*zlcache_ptr
; // NULL or &zlcache
377 struct zone
*zones
[MAX_ZONES_PER_ZONELIST
+ 1]; // NULL delimited
379 struct zonelist_cache zlcache
; // optional ...
383 #ifdef CONFIG_ARCH_POPULATES_NODE_MAP
384 struct node_active_region
{
385 unsigned long start_pfn
;
386 unsigned long end_pfn
;
389 #endif /* CONFIG_ARCH_POPULATES_NODE_MAP */
391 #ifndef CONFIG_DISCONTIGMEM
392 /* The array of struct pages - for discontigmem use pgdat->lmem_map */
393 extern struct page
*mem_map
;
397 * The pg_data_t structure is used in machines with CONFIG_DISCONTIGMEM
398 * (mostly NUMA machines?) to denote a higher-level memory zone than the
401 * On NUMA machines, each NUMA node would have a pg_data_t to describe
402 * it's memory layout.
404 * Memory statistics and page replacement data structures are maintained on a
408 typedef struct pglist_data
{
409 struct zone node_zones
[MAX_NR_ZONES
];
410 struct zonelist node_zonelists
[MAX_NR_ZONES
];
412 #ifdef CONFIG_FLAT_NODE_MEM_MAP
413 struct page
*node_mem_map
;
415 struct bootmem_data
*bdata
;
416 #ifdef CONFIG_MEMORY_HOTPLUG
418 * Must be held any time you expect node_start_pfn, node_present_pages
419 * or node_spanned_pages stay constant. Holding this will also
420 * guarantee that any pfn_valid() stays that way.
422 * Nests above zone->lock and zone->size_seqlock.
424 spinlock_t node_size_lock
;
426 unsigned long node_start_pfn
;
427 unsigned long node_present_pages
; /* total number of physical pages */
428 unsigned long node_spanned_pages
; /* total size of physical page
429 range, including holes */
431 wait_queue_head_t kswapd_wait
;
432 struct task_struct
*kswapd
;
433 int kswapd_max_order
;
436 #define node_present_pages(nid) (NODE_DATA(nid)->node_present_pages)
437 #define node_spanned_pages(nid) (NODE_DATA(nid)->node_spanned_pages)
438 #ifdef CONFIG_FLAT_NODE_MEM_MAP
439 #define pgdat_page_nr(pgdat, pagenr) ((pgdat)->node_mem_map + (pagenr))
441 #define pgdat_page_nr(pgdat, pagenr) pfn_to_page((pgdat)->node_start_pfn + (pagenr))
443 #define nid_page_nr(nid, pagenr) pgdat_page_nr(NODE_DATA(nid),(pagenr))
445 #include <linux/memory_hotplug.h>
447 void __get_zone_counts(unsigned long *active
, unsigned long *inactive
,
448 unsigned long *free
, struct pglist_data
*pgdat
);
449 void get_zone_counts(unsigned long *active
, unsigned long *inactive
,
450 unsigned long *free
);
451 void build_all_zonelists(void);
452 void wakeup_kswapd(struct zone
*zone
, int order
);
453 int zone_watermark_ok(struct zone
*z
, int order
, unsigned long mark
,
454 int classzone_idx
, int alloc_flags
);
455 enum memmap_context
{
459 extern int init_currently_empty_zone(struct zone
*zone
, unsigned long start_pfn
,
461 enum memmap_context context
);
463 #ifdef CONFIG_HAVE_MEMORY_PRESENT
464 void memory_present(int nid
, unsigned long start
, unsigned long end
);
466 static inline void memory_present(int nid
, unsigned long start
, unsigned long end
) {}
469 #ifdef CONFIG_NEED_NODE_MEMMAP_SIZE
470 unsigned long __init
node_memmap_size_bytes(int, unsigned long, unsigned long);
474 * zone_idx() returns 0 for the ZONE_DMA zone, 1 for the ZONE_NORMAL zone, etc.
476 #define zone_idx(zone) ((zone) - (zone)->zone_pgdat->node_zones)
478 static inline int populated_zone(struct zone
*zone
)
480 return (!!zone
->present_pages
);
483 static inline int is_highmem_idx(enum zone_type idx
)
485 #ifdef CONFIG_HIGHMEM
486 return (idx
== ZONE_HIGHMEM
);
492 static inline int is_normal_idx(enum zone_type idx
)
494 return (idx
== ZONE_NORMAL
);
498 * is_highmem - helper function to quickly check if a struct zone is a
499 * highmem zone or not. This is an attempt to keep references
500 * to ZONE_{DMA/NORMAL/HIGHMEM/etc} in general code to a minimum.
501 * @zone - pointer to struct zone variable
503 static inline int is_highmem(struct zone
*zone
)
505 #ifdef CONFIG_HIGHMEM
506 return zone
== zone
->zone_pgdat
->node_zones
+ ZONE_HIGHMEM
;
512 static inline int is_normal(struct zone
*zone
)
514 return zone
== zone
->zone_pgdat
->node_zones
+ ZONE_NORMAL
;
517 static inline int is_dma32(struct zone
*zone
)
519 #ifdef CONFIG_ZONE_DMA32
520 return zone
== zone
->zone_pgdat
->node_zones
+ ZONE_DMA32
;
526 static inline int is_dma(struct zone
*zone
)
528 return zone
== zone
->zone_pgdat
->node_zones
+ ZONE_DMA
;
531 /* These two functions are used to setup the per zone pages min values */
534 int min_free_kbytes_sysctl_handler(struct ctl_table
*, int, struct file
*,
535 void __user
*, size_t *, loff_t
*);
536 extern int sysctl_lowmem_reserve_ratio
[MAX_NR_ZONES
-1];
537 int lowmem_reserve_ratio_sysctl_handler(struct ctl_table
*, int, struct file
*,
538 void __user
*, size_t *, loff_t
*);
539 int percpu_pagelist_fraction_sysctl_handler(struct ctl_table
*, int, struct file
*,
540 void __user
*, size_t *, loff_t
*);
541 int sysctl_min_unmapped_ratio_sysctl_handler(struct ctl_table
*, int,
542 struct file
*, void __user
*, size_t *, loff_t
*);
543 int sysctl_min_slab_ratio_sysctl_handler(struct ctl_table
*, int,
544 struct file
*, void __user
*, size_t *, loff_t
*);
546 #include <linux/topology.h>
547 /* Returns the number of the current Node. */
549 #define numa_node_id() (cpu_to_node(raw_smp_processor_id()))
552 #ifndef CONFIG_NEED_MULTIPLE_NODES
554 extern struct pglist_data contig_page_data
;
555 #define NODE_DATA(nid) (&contig_page_data)
556 #define NODE_MEM_MAP(nid) mem_map
557 #define MAX_NODES_SHIFT 1
559 #else /* CONFIG_NEED_MULTIPLE_NODES */
561 #include <asm/mmzone.h>
563 #endif /* !CONFIG_NEED_MULTIPLE_NODES */
565 extern struct pglist_data
*first_online_pgdat(void);
566 extern struct pglist_data
*next_online_pgdat(struct pglist_data
*pgdat
);
567 extern struct zone
*next_zone(struct zone
*zone
);
570 * for_each_pgdat - helper macro to iterate over all nodes
571 * @pgdat - pointer to a pg_data_t variable
573 #define for_each_online_pgdat(pgdat) \
574 for (pgdat = first_online_pgdat(); \
576 pgdat = next_online_pgdat(pgdat))
578 * for_each_zone - helper macro to iterate over all memory zones
579 * @zone - pointer to struct zone variable
581 * The user only needs to declare the zone variable, for_each_zone
584 #define for_each_zone(zone) \
585 for (zone = (first_online_pgdat())->node_zones; \
587 zone = next_zone(zone))
589 #ifdef CONFIG_SPARSEMEM
590 #include <asm/sparsemem.h>
593 #if BITS_PER_LONG == 32
595 * with 32 bit page->flags field, we reserve 9 bits for node/zone info.
596 * there are 4 zones (3 bits) and this leaves 9-3=6 bits for nodes.
598 #define FLAGS_RESERVED 9
600 #elif BITS_PER_LONG == 64
602 * with 64 bit flags field, there's plenty of room.
604 #define FLAGS_RESERVED 32
608 #error BITS_PER_LONG not defined
612 #if !defined(CONFIG_HAVE_ARCH_EARLY_PFN_TO_NID) && \
613 !defined(CONFIG_ARCH_POPULATES_NODE_MAP)
614 #define early_pfn_to_nid(nid) (0UL)
617 #ifdef CONFIG_FLATMEM
618 #define pfn_to_nid(pfn) (0)
621 #define pfn_to_section_nr(pfn) ((pfn) >> PFN_SECTION_SHIFT)
622 #define section_nr_to_pfn(sec) ((sec) << PFN_SECTION_SHIFT)
624 #ifdef CONFIG_SPARSEMEM
627 * SECTION_SHIFT #bits space required to store a section #
629 * PA_SECTION_SHIFT physical address to/from section number
630 * PFN_SECTION_SHIFT pfn to/from section number
632 #define SECTIONS_SHIFT (MAX_PHYSMEM_BITS - SECTION_SIZE_BITS)
634 #define PA_SECTION_SHIFT (SECTION_SIZE_BITS)
635 #define PFN_SECTION_SHIFT (SECTION_SIZE_BITS - PAGE_SHIFT)
637 #define NR_MEM_SECTIONS (1UL << SECTIONS_SHIFT)
639 #define PAGES_PER_SECTION (1UL << PFN_SECTION_SHIFT)
640 #define PAGE_SECTION_MASK (~(PAGES_PER_SECTION-1))
642 #if (MAX_ORDER - 1 + PAGE_SHIFT) > SECTION_SIZE_BITS
643 #error Allocator MAX_ORDER exceeds SECTION_SIZE
649 * This is, logically, a pointer to an array of struct
650 * pages. However, it is stored with some other magic.
651 * (see sparse.c::sparse_init_one_section())
653 * Additionally during early boot we encode node id of
654 * the location of the section here to guide allocation.
655 * (see sparse.c::memory_present())
657 * Making it a UL at least makes someone do a cast
658 * before using it wrong.
660 unsigned long section_mem_map
;
663 #ifdef CONFIG_SPARSEMEM_EXTREME
664 #define SECTIONS_PER_ROOT (PAGE_SIZE / sizeof (struct mem_section))
666 #define SECTIONS_PER_ROOT 1
669 #define SECTION_NR_TO_ROOT(sec) ((sec) / SECTIONS_PER_ROOT)
670 #define NR_SECTION_ROOTS (NR_MEM_SECTIONS / SECTIONS_PER_ROOT)
671 #define SECTION_ROOT_MASK (SECTIONS_PER_ROOT - 1)
673 #ifdef CONFIG_SPARSEMEM_EXTREME
674 extern struct mem_section
*mem_section
[NR_SECTION_ROOTS
];
676 extern struct mem_section mem_section
[NR_SECTION_ROOTS
][SECTIONS_PER_ROOT
];
679 static inline struct mem_section
*__nr_to_section(unsigned long nr
)
681 if (!mem_section
[SECTION_NR_TO_ROOT(nr
)])
683 return &mem_section
[SECTION_NR_TO_ROOT(nr
)][nr
& SECTION_ROOT_MASK
];
685 extern int __section_nr(struct mem_section
* ms
);
688 * We use the lower bits of the mem_map pointer to store
689 * a little bit of information. There should be at least
690 * 3 bits here due to 32-bit alignment.
692 #define SECTION_MARKED_PRESENT (1UL<<0)
693 #define SECTION_HAS_MEM_MAP (1UL<<1)
694 #define SECTION_MAP_LAST_BIT (1UL<<2)
695 #define SECTION_MAP_MASK (~(SECTION_MAP_LAST_BIT-1))
696 #define SECTION_NID_SHIFT 2
698 static inline struct page
*__section_mem_map_addr(struct mem_section
*section
)
700 unsigned long map
= section
->section_mem_map
;
701 map
&= SECTION_MAP_MASK
;
702 return (struct page
*)map
;
705 static inline int valid_section(struct mem_section
*section
)
707 return (section
&& (section
->section_mem_map
& SECTION_MARKED_PRESENT
));
710 static inline int section_has_mem_map(struct mem_section
*section
)
712 return (section
&& (section
->section_mem_map
& SECTION_HAS_MEM_MAP
));
715 static inline int valid_section_nr(unsigned long nr
)
717 return valid_section(__nr_to_section(nr
));
720 static inline struct mem_section
*__pfn_to_section(unsigned long pfn
)
722 return __nr_to_section(pfn_to_section_nr(pfn
));
725 static inline int pfn_valid(unsigned long pfn
)
727 if (pfn_to_section_nr(pfn
) >= NR_MEM_SECTIONS
)
729 return valid_section(__nr_to_section(pfn_to_section_nr(pfn
)));
733 * These are _only_ used during initialisation, therefore they
734 * can use __initdata ... They could have names to indicate
738 #define pfn_to_nid(pfn) \
740 unsigned long __pfn_to_nid_pfn = (pfn); \
741 page_to_nid(pfn_to_page(__pfn_to_nid_pfn)); \
744 #define pfn_to_nid(pfn) (0)
747 #define early_pfn_valid(pfn) pfn_valid(pfn)
748 void sparse_init(void);
750 #define sparse_init() do {} while (0)
751 #define sparse_index_init(_sec, _nid) do {} while (0)
752 #endif /* CONFIG_SPARSEMEM */
754 #ifdef CONFIG_NODES_SPAN_OTHER_NODES
755 #define early_pfn_in_nid(pfn, nid) (early_pfn_to_nid(pfn) == (nid))
757 #define early_pfn_in_nid(pfn, nid) (1)
760 #ifndef early_pfn_valid
761 #define early_pfn_valid(pfn) (1)
764 void memory_present(int nid
, unsigned long start
, unsigned long end
);
765 unsigned long __init
node_memmap_size_bytes(int, unsigned long, unsigned long);
767 #endif /* !__ASSEMBLY__ */
768 #endif /* __KERNEL__ */
769 #endif /* _LINUX_MMZONE_H */