4 #include <linux/errno.h>
9 #include <linux/list.h>
10 #include <linux/mmzone.h>
11 #include <linux/rbtree.h>
12 #include <linux/prio_tree.h>
14 #include <linux/mutex.h>
15 #include <linux/debug_locks.h>
16 #include <linux/backing-dev.h>
17 #include <linux/mm_types.h>
23 #ifndef CONFIG_DISCONTIGMEM /* Don't use mapnrs, do it properly */
24 extern unsigned long max_mapnr
;
27 extern unsigned long num_physpages
;
28 extern void * high_memory
;
29 extern int page_cluster
;
32 extern int sysctl_legacy_va_layout
;
34 #define sysctl_legacy_va_layout 0
38 #include <asm/pgtable.h>
39 #include <asm/processor.h>
41 #define nth_page(page,n) pfn_to_page(page_to_pfn((page)) + (n))
44 * Linux kernel virtual memory manager primitives.
45 * The idea being to have a "virtual" mm in the same way
46 * we have a virtual fs - giving a cleaner interface to the
47 * mm details, and allowing different kinds of memory mappings
48 * (from shared memory to executable loading to arbitrary
53 * This struct defines a memory VMM memory area. There is one of these
54 * per VM-area/task. A VM area is any part of the process virtual memory
55 * space that has a special rule for the page-fault handlers (ie a shared
56 * library, the executable area etc).
58 struct vm_area_struct
{
59 struct mm_struct
* vm_mm
; /* The address space we belong to. */
60 unsigned long vm_start
; /* Our start address within vm_mm. */
61 unsigned long vm_end
; /* The first byte after our end address
64 /* linked list of VM areas per task, sorted by address */
65 struct vm_area_struct
*vm_next
;
67 pgprot_t vm_page_prot
; /* Access permissions of this VMA. */
68 unsigned long vm_flags
; /* Flags, listed below. */
73 * For areas with an address space and backing store,
74 * linkage into the address_space->i_mmap prio tree, or
75 * linkage to the list of like vmas hanging off its node, or
76 * linkage of vma in the address_space->i_mmap_nonlinear list.
80 struct list_head list
;
81 void *parent
; /* aligns with prio_tree_node parent */
82 struct vm_area_struct
*head
;
85 struct raw_prio_tree_node prio_tree_node
;
89 * A file's MAP_PRIVATE vma can be in both i_mmap tree and anon_vma
90 * list, after a COW of one of the file pages. A MAP_SHARED vma
91 * can only be in the i_mmap tree. An anonymous MAP_PRIVATE, stack
92 * or brk vma (with NULL file) can only be in an anon_vma list.
94 struct list_head anon_vma_node
; /* Serialized by anon_vma->lock */
95 struct anon_vma
*anon_vma
; /* Serialized by page_table_lock */
97 /* Function pointers to deal with this struct. */
98 struct vm_operations_struct
* vm_ops
;
100 /* Information about our backing store: */
101 unsigned long vm_pgoff
; /* Offset (within vm_file) in PAGE_SIZE
102 units, *not* PAGE_CACHE_SIZE */
103 struct file
* vm_file
; /* File we map to (can be NULL). */
104 void * vm_private_data
; /* was vm_pte (shared mem) */
105 unsigned long vm_truncate_count
;/* truncate_count or restart_addr */
108 atomic_t vm_usage
; /* refcount (VMAs shared if !MMU) */
111 struct mempolicy
*vm_policy
; /* NUMA policy for the VMA */
115 extern struct kmem_cache
*vm_area_cachep
;
118 * This struct defines the per-mm list of VMAs for uClinux. If CONFIG_MMU is
119 * disabled, then there's a single shared list of VMAs maintained by the
120 * system, and mm's subscribe to these individually
122 struct vm_list_struct
{
123 struct vm_list_struct
*next
;
124 struct vm_area_struct
*vma
;
128 extern struct rb_root nommu_vma_tree
;
129 extern struct rw_semaphore nommu_vma_sem
;
131 extern unsigned int kobjsize(const void *objp
);
137 #define VM_READ 0x00000001 /* currently active flags */
138 #define VM_WRITE 0x00000002
139 #define VM_EXEC 0x00000004
140 #define VM_SHARED 0x00000008
142 /* mprotect() hardcodes VM_MAYREAD >> 4 == VM_READ, and so for r/w/x bits. */
143 #define VM_MAYREAD 0x00000010 /* limits for mprotect() etc */
144 #define VM_MAYWRITE 0x00000020
145 #define VM_MAYEXEC 0x00000040
146 #define VM_MAYSHARE 0x00000080
148 #define VM_GROWSDOWN 0x00000100 /* general info on the segment */
149 #define VM_GROWSUP 0x00000200
150 #define VM_PFNMAP 0x00000400 /* Page-ranges managed without "struct page", just pure PFN */
151 #define VM_DENYWRITE 0x00000800 /* ETXTBSY on write attempts.. */
153 #define VM_EXECUTABLE 0x00001000
154 #define VM_LOCKED 0x00002000
155 #define VM_IO 0x00004000 /* Memory mapped I/O or similar */
157 /* Used by sys_madvise() */
158 #define VM_SEQ_READ 0x00008000 /* App will access data sequentially */
159 #define VM_RAND_READ 0x00010000 /* App will not benefit from clustered reads */
161 #define VM_DONTCOPY 0x00020000 /* Do not copy this vma on fork */
162 #define VM_DONTEXPAND 0x00040000 /* Cannot expand with mremap() */
163 #define VM_RESERVED 0x00080000 /* Count as reserved_vm like IO */
164 #define VM_ACCOUNT 0x00100000 /* Is a VM accounted object */
165 #define VM_HUGETLB 0x00400000 /* Huge TLB Page VM */
166 #define VM_NONLINEAR 0x00800000 /* Is non-linear (remap_file_pages) */
167 #define VM_MAPPED_COPY 0x01000000 /* T if mapped copy of data (nommu mmap) */
168 #define VM_INSERTPAGE 0x02000000 /* The vma has had "vm_insert_page()" done on it */
169 #define VM_ALWAYSDUMP 0x04000000 /* Always include in core dumps */
171 #define VM_CAN_NONLINEAR 0x08000000 /* Has ->fault & does nonlinear pages */
173 #ifndef VM_STACK_DEFAULT_FLAGS /* arch can override this */
174 #define VM_STACK_DEFAULT_FLAGS VM_DATA_DEFAULT_FLAGS
177 #ifdef CONFIG_STACK_GROWSUP
178 #define VM_STACK_FLAGS (VM_GROWSUP | VM_STACK_DEFAULT_FLAGS | VM_ACCOUNT)
180 #define VM_STACK_FLAGS (VM_GROWSDOWN | VM_STACK_DEFAULT_FLAGS | VM_ACCOUNT)
183 #define VM_READHINTMASK (VM_SEQ_READ | VM_RAND_READ)
184 #define VM_ClearReadHint(v) (v)->vm_flags &= ~VM_READHINTMASK
185 #define VM_NormalReadHint(v) (!((v)->vm_flags & VM_READHINTMASK))
186 #define VM_SequentialReadHint(v) ((v)->vm_flags & VM_SEQ_READ)
187 #define VM_RandomReadHint(v) ((v)->vm_flags & VM_RAND_READ)
190 * mapping from the currently active vm_flags protection bits (the
191 * low four bits) to a page protection mask..
193 extern pgprot_t protection_map
[16];
195 #define FAULT_FLAG_WRITE 0x01 /* Fault was a write access */
196 #define FAULT_FLAG_NONLINEAR 0x02 /* Fault was via a nonlinear mapping */
199 #define FAULT_RET_NOPAGE 0x0100 /* ->fault did not return a page. This
200 * can be used if the handler installs
203 #define FAULT_RET_LOCKED 0x0200 /* ->fault locked the page, caller must
204 * unlock after installing the mapping.
205 * This is used by pagecache in
206 * particular, where the page lock is
207 * used to synchronise against truncate
208 * and invalidate. Mutually exclusive
209 * with FAULT_RET_NOPAGE.
213 * vm_fault is filled by the the pagefault handler and passed to the vma's
214 * ->fault function. The vma's ->fault is responsible for returning the
215 * VM_FAULT_xxx type which occupies the lowest byte of the return code, ORed
216 * with FAULT_RET_ flags that occupy the next byte and give details about
217 * how the fault was handled.
219 * pgoff should be used in favour of virtual_address, if possible. If pgoff
220 * is used, one may set VM_CAN_NONLINEAR in the vma->vm_flags to get nonlinear
224 unsigned int flags
; /* FAULT_FLAG_xxx flags */
225 pgoff_t pgoff
; /* Logical page offset based on vma */
226 void __user
*virtual_address
; /* Faulting virtual address */
228 struct page
*page
; /* ->fault handlers should return a
229 * page here, unless FAULT_RET_NOPAGE
230 * is set (which is also implied by
231 * VM_FAULT_OOM or SIGBUS).
236 * These are the virtual MM functions - opening of an area, closing and
237 * unmapping it (needed to keep files on disk up-to-date etc), pointer
238 * to the functions called when a no-page or a wp-page exception occurs.
240 struct vm_operations_struct
{
241 void (*open
)(struct vm_area_struct
* area
);
242 void (*close
)(struct vm_area_struct
* area
);
243 int (*fault
)(struct vm_area_struct
*vma
, struct vm_fault
*vmf
);
244 struct page
*(*nopage
)(struct vm_area_struct
*area
,
245 unsigned long address
, int *type
);
246 unsigned long (*nopfn
)(struct vm_area_struct
*area
,
247 unsigned long address
);
249 /* notification that a previously read-only page is about to become
250 * writable, if an error is returned it will cause a SIGBUS */
251 int (*page_mkwrite
)(struct vm_area_struct
*vma
, struct page
*page
);
253 int (*set_policy
)(struct vm_area_struct
*vma
, struct mempolicy
*new);
254 struct mempolicy
*(*get_policy
)(struct vm_area_struct
*vma
,
256 int (*migrate
)(struct vm_area_struct
*vma
, const nodemask_t
*from
,
257 const nodemask_t
*to
, unsigned long flags
);
264 #define page_private(page) ((page)->private)
265 #define set_page_private(page, v) ((page)->private = (v))
268 * FIXME: take this include out, include page-flags.h in
269 * files which need it (119 of them)
271 #include <linux/page-flags.h>
273 #ifdef CONFIG_DEBUG_VM
274 #define VM_BUG_ON(cond) BUG_ON(cond)
276 #define VM_BUG_ON(condition) do { } while(0)
280 * Methods to modify the page usage count.
282 * What counts for a page usage:
283 * - cache mapping (page->mapping)
284 * - private data (page->private)
285 * - page mapped in a task's page tables, each mapping
286 * is counted separately
288 * Also, many kernel routines increase the page count before a critical
289 * routine so they can be sure the page doesn't go away from under them.
293 * Drop a ref, return true if the refcount fell to zero (the page has no users)
295 static inline int put_page_testzero(struct page
*page
)
297 VM_BUG_ON(atomic_read(&page
->_count
) == 0);
298 return atomic_dec_and_test(&page
->_count
);
302 * Try to grab a ref unless the page has a refcount of zero, return false if
305 static inline int get_page_unless_zero(struct page
*page
)
307 VM_BUG_ON(PageCompound(page
));
308 return atomic_inc_not_zero(&page
->_count
);
311 static inline struct page
*compound_head(struct page
*page
)
313 if (unlikely(PageTail(page
)))
314 return page
->first_page
;
318 static inline int page_count(struct page
*page
)
320 return atomic_read(&compound_head(page
)->_count
);
323 static inline void get_page(struct page
*page
)
325 page
= compound_head(page
);
326 VM_BUG_ON(atomic_read(&page
->_count
) == 0);
327 atomic_inc(&page
->_count
);
330 static inline struct page
*virt_to_head_page(const void *x
)
332 struct page
*page
= virt_to_page(x
);
333 return compound_head(page
);
337 * Setup the page count before being freed into the page allocator for
338 * the first time (boot or memory hotplug)
340 static inline void init_page_count(struct page
*page
)
342 atomic_set(&page
->_count
, 1);
345 void put_page(struct page
*page
);
346 void put_pages_list(struct list_head
*pages
);
348 void split_page(struct page
*page
, unsigned int order
);
351 * Compound pages have a destructor function. Provide a
352 * prototype for that function and accessor functions.
353 * These are _only_ valid on the head of a PG_compound page.
355 typedef void compound_page_dtor(struct page
*);
357 static inline void set_compound_page_dtor(struct page
*page
,
358 compound_page_dtor
*dtor
)
360 page
[1].lru
.next
= (void *)dtor
;
363 static inline compound_page_dtor
*get_compound_page_dtor(struct page
*page
)
365 return (compound_page_dtor
*)page
[1].lru
.next
;
368 static inline int compound_order(struct page
*page
)
372 return (unsigned long)page
[1].lru
.prev
;
375 static inline void set_compound_order(struct page
*page
, unsigned long order
)
377 page
[1].lru
.prev
= (void *)order
;
381 * Multiple processes may "see" the same page. E.g. for untouched
382 * mappings of /dev/null, all processes see the same page full of
383 * zeroes, and text pages of executables and shared libraries have
384 * only one copy in memory, at most, normally.
386 * For the non-reserved pages, page_count(page) denotes a reference count.
387 * page_count() == 0 means the page is free. page->lru is then used for
388 * freelist management in the buddy allocator.
389 * page_count() > 0 means the page has been allocated.
391 * Pages are allocated by the slab allocator in order to provide memory
392 * to kmalloc and kmem_cache_alloc. In this case, the management of the
393 * page, and the fields in 'struct page' are the responsibility of mm/slab.c
394 * unless a particular usage is carefully commented. (the responsibility of
395 * freeing the kmalloc memory is the caller's, of course).
397 * A page may be used by anyone else who does a __get_free_page().
398 * In this case, page_count still tracks the references, and should only
399 * be used through the normal accessor functions. The top bits of page->flags
400 * and page->virtual store page management information, but all other fields
401 * are unused and could be used privately, carefully. The management of this
402 * page is the responsibility of the one who allocated it, and those who have
403 * subsequently been given references to it.
405 * The other pages (we may call them "pagecache pages") are completely
406 * managed by the Linux memory manager: I/O, buffers, swapping etc.
407 * The following discussion applies only to them.
409 * A pagecache page contains an opaque `private' member, which belongs to the
410 * page's address_space. Usually, this is the address of a circular list of
411 * the page's disk buffers. PG_private must be set to tell the VM to call
412 * into the filesystem to release these pages.
414 * A page may belong to an inode's memory mapping. In this case, page->mapping
415 * is the pointer to the inode, and page->index is the file offset of the page,
416 * in units of PAGE_CACHE_SIZE.
418 * If pagecache pages are not associated with an inode, they are said to be
419 * anonymous pages. These may become associated with the swapcache, and in that
420 * case PG_swapcache is set, and page->private is an offset into the swapcache.
422 * In either case (swapcache or inode backed), the pagecache itself holds one
423 * reference to the page. Setting PG_private should also increment the
424 * refcount. The each user mapping also has a reference to the page.
426 * The pagecache pages are stored in a per-mapping radix tree, which is
427 * rooted at mapping->page_tree, and indexed by offset.
428 * Where 2.4 and early 2.6 kernels kept dirty/clean pages in per-address_space
429 * lists, we instead now tag pages as dirty/writeback in the radix tree.
431 * All pagecache pages may be subject to I/O:
432 * - inode pages may need to be read from disk,
433 * - inode pages which have been modified and are MAP_SHARED may need
434 * to be written back to the inode on disk,
435 * - anonymous pages (including MAP_PRIVATE file mappings) which have been
436 * modified may need to be swapped out to swap space and (later) to be read
441 * The zone field is never updated after free_area_init_core()
442 * sets it, so none of the operations on it need to be atomic.
447 * page->flags layout:
449 * There are three possibilities for how page->flags get
450 * laid out. The first is for the normal case, without
451 * sparsemem. The second is for sparsemem when there is
452 * plenty of space for node and section. The last is when
453 * we have run out of space and have to fall back to an
454 * alternate (slower) way of determining the node.
456 * No sparsemem: | NODE | ZONE | ... | FLAGS |
457 * with space for node: | SECTION | NODE | ZONE | ... | FLAGS |
458 * no space for node: | SECTION | ZONE | ... | FLAGS |
460 #ifdef CONFIG_SPARSEMEM
461 #define SECTIONS_WIDTH SECTIONS_SHIFT
463 #define SECTIONS_WIDTH 0
466 #define ZONES_WIDTH ZONES_SHIFT
468 #if SECTIONS_WIDTH+ZONES_WIDTH+NODES_SHIFT <= FLAGS_RESERVED
469 #define NODES_WIDTH NODES_SHIFT
471 #define NODES_WIDTH 0
474 /* Page flags: | [SECTION] | [NODE] | ZONE | ... | FLAGS | */
475 #define SECTIONS_PGOFF ((sizeof(unsigned long)*8) - SECTIONS_WIDTH)
476 #define NODES_PGOFF (SECTIONS_PGOFF - NODES_WIDTH)
477 #define ZONES_PGOFF (NODES_PGOFF - ZONES_WIDTH)
480 * We are going to use the flags for the page to node mapping if its in
481 * there. This includes the case where there is no node, so it is implicit.
483 #if !(NODES_WIDTH > 0 || NODES_SHIFT == 0)
484 #define NODE_NOT_IN_PAGE_FLAGS
487 #ifndef PFN_SECTION_SHIFT
488 #define PFN_SECTION_SHIFT 0
492 * Define the bit shifts to access each section. For non-existant
493 * sections we define the shift as 0; that plus a 0 mask ensures
494 * the compiler will optimise away reference to them.
496 #define SECTIONS_PGSHIFT (SECTIONS_PGOFF * (SECTIONS_WIDTH != 0))
497 #define NODES_PGSHIFT (NODES_PGOFF * (NODES_WIDTH != 0))
498 #define ZONES_PGSHIFT (ZONES_PGOFF * (ZONES_WIDTH != 0))
500 /* NODE:ZONE or SECTION:ZONE is used to ID a zone for the buddy allcator */
501 #ifdef NODE_NOT_IN_PAGEFLAGS
502 #define ZONEID_SHIFT (SECTIONS_SHIFT + ZONES_SHIFT)
503 #define ZONEID_PGOFF ((SECTIONS_PGOFF < ZONES_PGOFF)? \
504 SECTIONS_PGOFF : ZONES_PGOFF)
506 #define ZONEID_SHIFT (NODES_SHIFT + ZONES_SHIFT)
507 #define ZONEID_PGOFF ((NODES_PGOFF < ZONES_PGOFF)? \
508 NODES_PGOFF : ZONES_PGOFF)
511 #define ZONEID_PGSHIFT (ZONEID_PGOFF * (ZONEID_SHIFT != 0))
513 #if SECTIONS_WIDTH+NODES_WIDTH+ZONES_WIDTH > FLAGS_RESERVED
514 #error SECTIONS_WIDTH+NODES_WIDTH+ZONES_WIDTH > FLAGS_RESERVED
517 #define ZONES_MASK ((1UL << ZONES_WIDTH) - 1)
518 #define NODES_MASK ((1UL << NODES_WIDTH) - 1)
519 #define SECTIONS_MASK ((1UL << SECTIONS_WIDTH) - 1)
520 #define ZONEID_MASK ((1UL << ZONEID_SHIFT) - 1)
522 static inline enum zone_type
page_zonenum(struct page
*page
)
524 return (page
->flags
>> ZONES_PGSHIFT
) & ZONES_MASK
;
528 * The identification function is only used by the buddy allocator for
529 * determining if two pages could be buddies. We are not really
530 * identifying a zone since we could be using a the section number
531 * id if we have not node id available in page flags.
532 * We guarantee only that it will return the same value for two
533 * combinable pages in a zone.
535 static inline int page_zone_id(struct page
*page
)
537 return (page
->flags
>> ZONEID_PGSHIFT
) & ZONEID_MASK
;
540 static inline int zone_to_nid(struct zone
*zone
)
549 #ifdef NODE_NOT_IN_PAGE_FLAGS
550 extern int page_to_nid(struct page
*page
);
552 static inline int page_to_nid(struct page
*page
)
554 return (page
->flags
>> NODES_PGSHIFT
) & NODES_MASK
;
558 static inline struct zone
*page_zone(struct page
*page
)
560 return &NODE_DATA(page_to_nid(page
))->node_zones
[page_zonenum(page
)];
563 static inline unsigned long page_to_section(struct page
*page
)
565 return (page
->flags
>> SECTIONS_PGSHIFT
) & SECTIONS_MASK
;
568 static inline void set_page_zone(struct page
*page
, enum zone_type zone
)
570 page
->flags
&= ~(ZONES_MASK
<< ZONES_PGSHIFT
);
571 page
->flags
|= (zone
& ZONES_MASK
) << ZONES_PGSHIFT
;
574 static inline void set_page_node(struct page
*page
, unsigned long node
)
576 page
->flags
&= ~(NODES_MASK
<< NODES_PGSHIFT
);
577 page
->flags
|= (node
& NODES_MASK
) << NODES_PGSHIFT
;
580 static inline void set_page_section(struct page
*page
, unsigned long section
)
582 page
->flags
&= ~(SECTIONS_MASK
<< SECTIONS_PGSHIFT
);
583 page
->flags
|= (section
& SECTIONS_MASK
) << SECTIONS_PGSHIFT
;
586 static inline void set_page_links(struct page
*page
, enum zone_type zone
,
587 unsigned long node
, unsigned long pfn
)
589 set_page_zone(page
, zone
);
590 set_page_node(page
, node
);
591 set_page_section(page
, pfn_to_section_nr(pfn
));
595 * Some inline functions in vmstat.h depend on page_zone()
597 #include <linux/vmstat.h>
599 static __always_inline
void *lowmem_page_address(struct page
*page
)
601 return __va(page_to_pfn(page
) << PAGE_SHIFT
);
604 #if defined(CONFIG_HIGHMEM) && !defined(WANT_PAGE_VIRTUAL)
605 #define HASHED_PAGE_VIRTUAL
608 #if defined(WANT_PAGE_VIRTUAL)
609 #define page_address(page) ((page)->virtual)
610 #define set_page_address(page, address) \
612 (page)->virtual = (address); \
614 #define page_address_init() do { } while(0)
617 #if defined(HASHED_PAGE_VIRTUAL)
618 void *page_address(struct page
*page
);
619 void set_page_address(struct page
*page
, void *virtual);
620 void page_address_init(void);
623 #if !defined(HASHED_PAGE_VIRTUAL) && !defined(WANT_PAGE_VIRTUAL)
624 #define page_address(page) lowmem_page_address(page)
625 #define set_page_address(page, address) do { } while(0)
626 #define page_address_init() do { } while(0)
630 * On an anonymous page mapped into a user virtual memory area,
631 * page->mapping points to its anon_vma, not to a struct address_space;
632 * with the PAGE_MAPPING_ANON bit set to distinguish it.
634 * Please note that, confusingly, "page_mapping" refers to the inode
635 * address_space which maps the page from disk; whereas "page_mapped"
636 * refers to user virtual address space into which the page is mapped.
638 #define PAGE_MAPPING_ANON 1
640 extern struct address_space swapper_space
;
641 static inline struct address_space
*page_mapping(struct page
*page
)
643 struct address_space
*mapping
= page
->mapping
;
645 VM_BUG_ON(PageSlab(page
));
646 if (unlikely(PageSwapCache(page
)))
647 mapping
= &swapper_space
;
649 else if (unlikely(PageSlab(page
)))
652 else if (unlikely((unsigned long)mapping
& PAGE_MAPPING_ANON
))
657 static inline int PageAnon(struct page
*page
)
659 return ((unsigned long)page
->mapping
& PAGE_MAPPING_ANON
) != 0;
663 * Return the pagecache index of the passed page. Regular pagecache pages
664 * use ->index whereas swapcache pages use ->private
666 static inline pgoff_t
page_index(struct page
*page
)
668 if (unlikely(PageSwapCache(page
)))
669 return page_private(page
);
674 * The atomic page->_mapcount, like _count, starts from -1:
675 * so that transitions both from it and to it can be tracked,
676 * using atomic_inc_and_test and atomic_add_negative(-1).
678 static inline void reset_page_mapcount(struct page
*page
)
680 atomic_set(&(page
)->_mapcount
, -1);
683 static inline int page_mapcount(struct page
*page
)
685 return atomic_read(&(page
)->_mapcount
) + 1;
689 * Return true if this page is mapped into pagetables.
691 static inline int page_mapped(struct page
*page
)
693 return atomic_read(&(page
)->_mapcount
) >= 0;
697 * Error return values for the *_nopage functions
699 #define NOPAGE_SIGBUS (NULL)
700 #define NOPAGE_OOM ((struct page *) (-1))
703 * Error return values for the *_nopfn functions
705 #define NOPFN_SIGBUS ((unsigned long) -1)
706 #define NOPFN_OOM ((unsigned long) -2)
707 #define NOPFN_REFAULT ((unsigned long) -3)
710 * Different kinds of faults, as returned by handle_mm_fault().
711 * Used to decide whether a process gets delivered SIGBUS or
712 * just gets major/minor fault counters bumped up.
716 * VM_FAULT_ERROR is set for the error cases, to make some tests simpler.
718 #define VM_FAULT_ERROR 0x20
720 #define VM_FAULT_OOM (0x00 | VM_FAULT_ERROR)
721 #define VM_FAULT_SIGBUS (0x01 | VM_FAULT_ERROR)
722 #define VM_FAULT_MINOR 0x02
723 #define VM_FAULT_MAJOR 0x03
726 * Special case for get_user_pages.
727 * Must be in a distinct bit from the above VM_FAULT_ flags.
729 #define VM_FAULT_WRITE 0x10
732 * Mask of VM_FAULT_ flags
734 #define VM_FAULT_MASK 0xff
736 #define offset_in_page(p) ((unsigned long)(p) & ~PAGE_MASK)
738 extern void show_free_areas(void);
741 int shmem_set_policy(struct vm_area_struct
*vma
, struct mempolicy
*new);
742 struct mempolicy
*shmem_get_policy(struct vm_area_struct
*vma
,
744 int shmem_lock(struct file
*file
, int lock
, struct user_struct
*user
);
746 static inline int shmem_lock(struct file
*file
, int lock
,
747 struct user_struct
*user
)
752 static inline int shmem_set_policy(struct vm_area_struct
*vma
,
753 struct mempolicy
*new)
758 static inline struct mempolicy
*shmem_get_policy(struct vm_area_struct
*vma
,
764 struct file
*shmem_file_setup(char *name
, loff_t size
, unsigned long flags
);
766 int shmem_zero_setup(struct vm_area_struct
*);
769 extern unsigned long shmem_get_unmapped_area(struct file
*file
,
773 unsigned long flags
);
776 extern int can_do_mlock(void);
777 extern int user_shm_lock(size_t, struct user_struct
*);
778 extern void user_shm_unlock(size_t, struct user_struct
*);
781 * Parameter block passed down to zap_pte_range in exceptional cases.
784 struct vm_area_struct
*nonlinear_vma
; /* Check page->index if set */
785 struct address_space
*check_mapping
; /* Check page->mapping if set */
786 pgoff_t first_index
; /* Lowest page->index to unmap */
787 pgoff_t last_index
; /* Highest page->index to unmap */
788 spinlock_t
*i_mmap_lock
; /* For unmap_mapping_range: */
789 unsigned long truncate_count
; /* Compare vm_truncate_count */
792 struct page
*vm_normal_page(struct vm_area_struct
*, unsigned long, pte_t
);
793 unsigned long zap_page_range(struct vm_area_struct
*vma
, unsigned long address
,
794 unsigned long size
, struct zap_details
*);
795 unsigned long unmap_vmas(struct mmu_gather
**tlb
,
796 struct vm_area_struct
*start_vma
, unsigned long start_addr
,
797 unsigned long end_addr
, unsigned long *nr_accounted
,
798 struct zap_details
*);
799 void free_pgd_range(struct mmu_gather
**tlb
, unsigned long addr
,
800 unsigned long end
, unsigned long floor
, unsigned long ceiling
);
801 void free_pgtables(struct mmu_gather
**tlb
, struct vm_area_struct
*start_vma
,
802 unsigned long floor
, unsigned long ceiling
);
803 int copy_page_range(struct mm_struct
*dst
, struct mm_struct
*src
,
804 struct vm_area_struct
*vma
);
805 int zeromap_page_range(struct vm_area_struct
*vma
, unsigned long from
,
806 unsigned long size
, pgprot_t prot
);
807 void unmap_mapping_range(struct address_space
*mapping
,
808 loff_t
const holebegin
, loff_t
const holelen
, int even_cows
);
810 static inline void unmap_shared_mapping_range(struct address_space
*mapping
,
811 loff_t
const holebegin
, loff_t
const holelen
)
813 unmap_mapping_range(mapping
, holebegin
, holelen
, 0);
816 extern int vmtruncate(struct inode
* inode
, loff_t offset
);
817 extern int vmtruncate_range(struct inode
* inode
, loff_t offset
, loff_t end
);
820 extern int __handle_mm_fault(struct mm_struct
*mm
,struct vm_area_struct
*vma
,
821 unsigned long address
, int write_access
);
823 static inline int handle_mm_fault(struct mm_struct
*mm
,
824 struct vm_area_struct
*vma
, unsigned long address
,
827 return __handle_mm_fault(mm
, vma
, address
, write_access
) &
831 static inline int handle_mm_fault(struct mm_struct
*mm
,
832 struct vm_area_struct
*vma
, unsigned long address
,
835 /* should never happen if there's no MMU */
837 return VM_FAULT_SIGBUS
;
841 extern int make_pages_present(unsigned long addr
, unsigned long end
);
842 extern int access_process_vm(struct task_struct
*tsk
, unsigned long addr
, void *buf
, int len
, int write
);
843 void install_arg_page(struct vm_area_struct
*, struct page
*, unsigned long);
845 int get_user_pages(struct task_struct
*tsk
, struct mm_struct
*mm
, unsigned long start
,
846 int len
, int write
, int force
, struct page
**pages
, struct vm_area_struct
**vmas
);
847 void print_bad_pte(struct vm_area_struct
*, pte_t
, unsigned long);
849 extern int try_to_release_page(struct page
* page
, gfp_t gfp_mask
);
850 extern void do_invalidatepage(struct page
*page
, unsigned long offset
);
852 int __set_page_dirty_nobuffers(struct page
*page
);
853 int __set_page_dirty_no_writeback(struct page
*page
);
854 int redirty_page_for_writepage(struct writeback_control
*wbc
,
856 int FASTCALL(set_page_dirty(struct page
*page
));
857 int set_page_dirty_lock(struct page
*page
);
858 int clear_page_dirty_for_io(struct page
*page
);
860 extern unsigned long do_mremap(unsigned long addr
,
861 unsigned long old_len
, unsigned long new_len
,
862 unsigned long flags
, unsigned long new_addr
);
865 * A callback you can register to apply pressure to ageable caches.
867 * 'shrink' is passed a count 'nr_to_scan' and a 'gfpmask'. It should
868 * look through the least-recently-used 'nr_to_scan' entries and
869 * attempt to free them up. It should return the number of objects
870 * which remain in the cache. If it returns -1, it means it cannot do
871 * any scanning at this time (eg. there is a risk of deadlock).
873 * The 'gfpmask' refers to the allocation we are currently trying to
876 * Note that 'shrink' will be passed nr_to_scan == 0 when the VM is
877 * querying the cache size, so a fastpath for that case is appropriate.
880 int (*shrink
)(int nr_to_scan
, gfp_t gfp_mask
);
881 int seeks
; /* seeks to recreate an obj */
883 /* These are for internal use */
884 struct list_head list
;
885 long nr
; /* objs pending delete */
887 #define DEFAULT_SEEKS 2 /* A good number if you don't know better. */
888 extern void register_shrinker(struct shrinker
*);
889 extern void unregister_shrinker(struct shrinker
*);
892 * Some shared mappigns will want the pages marked read-only
893 * to track write events. If so, we'll downgrade vm_page_prot
894 * to the private version (using protection_map[] without the
897 static inline int vma_wants_writenotify(struct vm_area_struct
*vma
)
899 unsigned int vm_flags
= vma
->vm_flags
;
901 /* If it was private or non-writable, the write bit is already clear */
902 if ((vm_flags
& (VM_WRITE
|VM_SHARED
)) != ((VM_WRITE
|VM_SHARED
)))
905 /* The backer wishes to know when pages are first written to? */
906 if (vma
->vm_ops
&& vma
->vm_ops
->page_mkwrite
)
909 /* The open routine did something to the protections already? */
910 if (pgprot_val(vma
->vm_page_prot
) !=
911 pgprot_val(protection_map
[vm_flags
&
912 (VM_READ
|VM_WRITE
|VM_EXEC
|VM_SHARED
)]))
915 /* Specialty mapping? */
916 if (vm_flags
& (VM_PFNMAP
|VM_INSERTPAGE
))
919 /* Can the mapping track the dirty pages? */
920 return vma
->vm_file
&& vma
->vm_file
->f_mapping
&&
921 mapping_cap_account_dirty(vma
->vm_file
->f_mapping
);
924 extern pte_t
*FASTCALL(get_locked_pte(struct mm_struct
*mm
, unsigned long addr
, spinlock_t
**ptl
));
926 #ifdef __PAGETABLE_PUD_FOLDED
927 static inline int __pud_alloc(struct mm_struct
*mm
, pgd_t
*pgd
,
928 unsigned long address
)
933 int __pud_alloc(struct mm_struct
*mm
, pgd_t
*pgd
, unsigned long address
);
936 #ifdef __PAGETABLE_PMD_FOLDED
937 static inline int __pmd_alloc(struct mm_struct
*mm
, pud_t
*pud
,
938 unsigned long address
)
943 int __pmd_alloc(struct mm_struct
*mm
, pud_t
*pud
, unsigned long address
);
946 int __pte_alloc(struct mm_struct
*mm
, pmd_t
*pmd
, unsigned long address
);
947 int __pte_alloc_kernel(pmd_t
*pmd
, unsigned long address
);
950 * The following ifdef needed to get the 4level-fixup.h header to work.
951 * Remove it when 4level-fixup.h has been removed.
953 #if defined(CONFIG_MMU) && !defined(__ARCH_HAS_4LEVEL_HACK)
954 static inline pud_t
*pud_alloc(struct mm_struct
*mm
, pgd_t
*pgd
, unsigned long address
)
956 return (unlikely(pgd_none(*pgd
)) && __pud_alloc(mm
, pgd
, address
))?
957 NULL
: pud_offset(pgd
, address
);
960 static inline pmd_t
*pmd_alloc(struct mm_struct
*mm
, pud_t
*pud
, unsigned long address
)
962 return (unlikely(pud_none(*pud
)) && __pmd_alloc(mm
, pud
, address
))?
963 NULL
: pmd_offset(pud
, address
);
965 #endif /* CONFIG_MMU && !__ARCH_HAS_4LEVEL_HACK */
967 #if NR_CPUS >= CONFIG_SPLIT_PTLOCK_CPUS
969 * We tuck a spinlock to guard each pagetable page into its struct page,
970 * at page->private, with BUILD_BUG_ON to make sure that this will not
971 * overflow into the next struct page (as it might with DEBUG_SPINLOCK).
972 * When freeing, reset page->mapping so free_pages_check won't complain.
974 #define __pte_lockptr(page) &((page)->ptl)
975 #define pte_lock_init(_page) do { \
976 spin_lock_init(__pte_lockptr(_page)); \
978 #define pte_lock_deinit(page) ((page)->mapping = NULL)
979 #define pte_lockptr(mm, pmd) ({(void)(mm); __pte_lockptr(pmd_page(*(pmd)));})
982 * We use mm->page_table_lock to guard all pagetable pages of the mm.
984 #define pte_lock_init(page) do {} while (0)
985 #define pte_lock_deinit(page) do {} while (0)
986 #define pte_lockptr(mm, pmd) ({(void)(pmd); &(mm)->page_table_lock;})
987 #endif /* NR_CPUS < CONFIG_SPLIT_PTLOCK_CPUS */
989 #define pte_offset_map_lock(mm, pmd, address, ptlp) \
991 spinlock_t *__ptl = pte_lockptr(mm, pmd); \
992 pte_t *__pte = pte_offset_map(pmd, address); \
998 #define pte_unmap_unlock(pte, ptl) do { \
1003 #define pte_alloc_map(mm, pmd, address) \
1004 ((unlikely(!pmd_present(*(pmd))) && __pte_alloc(mm, pmd, address))? \
1005 NULL: pte_offset_map(pmd, address))
1007 #define pte_alloc_map_lock(mm, pmd, address, ptlp) \
1008 ((unlikely(!pmd_present(*(pmd))) && __pte_alloc(mm, pmd, address))? \
1009 NULL: pte_offset_map_lock(mm, pmd, address, ptlp))
1011 #define pte_alloc_kernel(pmd, address) \
1012 ((unlikely(!pmd_present(*(pmd))) && __pte_alloc_kernel(pmd, address))? \
1013 NULL: pte_offset_kernel(pmd, address))
1015 extern void free_area_init(unsigned long * zones_size
);
1016 extern void free_area_init_node(int nid
, pg_data_t
*pgdat
,
1017 unsigned long * zones_size
, unsigned long zone_start_pfn
,
1018 unsigned long *zholes_size
);
1019 #ifdef CONFIG_ARCH_POPULATES_NODE_MAP
1021 * With CONFIG_ARCH_POPULATES_NODE_MAP set, an architecture may initialise its
1022 * zones, allocate the backing mem_map and account for memory holes in a more
1023 * architecture independent manner. This is a substitute for creating the
1024 * zone_sizes[] and zholes_size[] arrays and passing them to
1025 * free_area_init_node()
1027 * An architecture is expected to register range of page frames backed by
1028 * physical memory with add_active_range() before calling
1029 * free_area_init_nodes() passing in the PFN each zone ends at. At a basic
1030 * usage, an architecture is expected to do something like
1032 * unsigned long max_zone_pfns[MAX_NR_ZONES] = {max_dma, max_normal_pfn,
1034 * for_each_valid_physical_page_range()
1035 * add_active_range(node_id, start_pfn, end_pfn)
1036 * free_area_init_nodes(max_zone_pfns);
1038 * If the architecture guarantees that there are no holes in the ranges
1039 * registered with add_active_range(), free_bootmem_active_regions()
1040 * will call free_bootmem_node() for each registered physical page range.
1041 * Similarly sparse_memory_present_with_active_regions() calls
1042 * memory_present() for each range when SPARSEMEM is enabled.
1044 * See mm/page_alloc.c for more information on each function exposed by
1045 * CONFIG_ARCH_POPULATES_NODE_MAP
1047 extern void free_area_init_nodes(unsigned long *max_zone_pfn
);
1048 extern void add_active_range(unsigned int nid
, unsigned long start_pfn
,
1049 unsigned long end_pfn
);
1050 extern void shrink_active_range(unsigned int nid
, unsigned long old_end_pfn
,
1051 unsigned long new_end_pfn
);
1052 extern void push_node_boundaries(unsigned int nid
, unsigned long start_pfn
,
1053 unsigned long end_pfn
);
1054 extern void remove_all_active_ranges(void);
1055 extern unsigned long absent_pages_in_range(unsigned long start_pfn
,
1056 unsigned long end_pfn
);
1057 extern void get_pfn_range_for_nid(unsigned int nid
,
1058 unsigned long *start_pfn
, unsigned long *end_pfn
);
1059 extern unsigned long find_min_pfn_with_active_regions(void);
1060 extern unsigned long find_max_pfn_with_active_regions(void);
1061 extern void free_bootmem_with_active_regions(int nid
,
1062 unsigned long max_low_pfn
);
1063 extern void sparse_memory_present_with_active_regions(int nid
);
1064 #ifndef CONFIG_HAVE_ARCH_EARLY_PFN_TO_NID
1065 extern int early_pfn_to_nid(unsigned long pfn
);
1066 #endif /* CONFIG_HAVE_ARCH_EARLY_PFN_TO_NID */
1067 #endif /* CONFIG_ARCH_POPULATES_NODE_MAP */
1068 extern void set_dma_reserve(unsigned long new_dma_reserve
);
1069 extern void memmap_init_zone(unsigned long, int, unsigned long,
1070 unsigned long, enum memmap_context
);
1071 extern void setup_per_zone_pages_min(void);
1072 extern void mem_init(void);
1073 extern void show_mem(void);
1074 extern void si_meminfo(struct sysinfo
* val
);
1075 extern void si_meminfo_node(struct sysinfo
*val
, int nid
);
1078 extern void setup_per_cpu_pageset(void);
1080 static inline void setup_per_cpu_pageset(void) {}
1084 void vma_prio_tree_add(struct vm_area_struct
*, struct vm_area_struct
*old
);
1085 void vma_prio_tree_insert(struct vm_area_struct
*, struct prio_tree_root
*);
1086 void vma_prio_tree_remove(struct vm_area_struct
*, struct prio_tree_root
*);
1087 struct vm_area_struct
*vma_prio_tree_next(struct vm_area_struct
*vma
,
1088 struct prio_tree_iter
*iter
);
1090 #define vma_prio_tree_foreach(vma, iter, root, begin, end) \
1091 for (prio_tree_iter_init(iter, root, begin, end), vma = NULL; \
1092 (vma = vma_prio_tree_next(vma, iter)); )
1094 static inline void vma_nonlinear_insert(struct vm_area_struct
*vma
,
1095 struct list_head
*list
)
1097 vma
->shared
.vm_set
.parent
= NULL
;
1098 list_add_tail(&vma
->shared
.vm_set
.list
, list
);
1102 extern int __vm_enough_memory(long pages
, int cap_sys_admin
);
1103 extern void vma_adjust(struct vm_area_struct
*vma
, unsigned long start
,
1104 unsigned long end
, pgoff_t pgoff
, struct vm_area_struct
*insert
);
1105 extern struct vm_area_struct
*vma_merge(struct mm_struct
*,
1106 struct vm_area_struct
*prev
, unsigned long addr
, unsigned long end
,
1107 unsigned long vm_flags
, struct anon_vma
*, struct file
*, pgoff_t
,
1108 struct mempolicy
*);
1109 extern struct anon_vma
*find_mergeable_anon_vma(struct vm_area_struct
*);
1110 extern int split_vma(struct mm_struct
*,
1111 struct vm_area_struct
*, unsigned long addr
, int new_below
);
1112 extern int insert_vm_struct(struct mm_struct
*, struct vm_area_struct
*);
1113 extern void __vma_link_rb(struct mm_struct
*, struct vm_area_struct
*,
1114 struct rb_node
**, struct rb_node
*);
1115 extern void unlink_file_vma(struct vm_area_struct
*);
1116 extern struct vm_area_struct
*copy_vma(struct vm_area_struct
**,
1117 unsigned long addr
, unsigned long len
, pgoff_t pgoff
);
1118 extern void exit_mmap(struct mm_struct
*);
1119 extern int may_expand_vm(struct mm_struct
*mm
, unsigned long npages
);
1120 extern int install_special_mapping(struct mm_struct
*mm
,
1121 unsigned long addr
, unsigned long len
,
1122 unsigned long flags
, struct page
**pages
);
1124 extern unsigned long get_unmapped_area(struct file
*, unsigned long, unsigned long, unsigned long, unsigned long);
1126 extern unsigned long do_mmap_pgoff(struct file
*file
, unsigned long addr
,
1127 unsigned long len
, unsigned long prot
,
1128 unsigned long flag
, unsigned long pgoff
);
1129 extern unsigned long mmap_region(struct file
*file
, unsigned long addr
,
1130 unsigned long len
, unsigned long flags
,
1131 unsigned int vm_flags
, unsigned long pgoff
,
1134 static inline unsigned long do_mmap(struct file
*file
, unsigned long addr
,
1135 unsigned long len
, unsigned long prot
,
1136 unsigned long flag
, unsigned long offset
)
1138 unsigned long ret
= -EINVAL
;
1139 if ((offset
+ PAGE_ALIGN(len
)) < offset
)
1141 if (!(offset
& ~PAGE_MASK
))
1142 ret
= do_mmap_pgoff(file
, addr
, len
, prot
, flag
, offset
>> PAGE_SHIFT
);
1147 extern int do_munmap(struct mm_struct
*, unsigned long, size_t);
1149 extern unsigned long do_brk(unsigned long, unsigned long);
1152 extern unsigned long page_unuse(struct page
*);
1153 extern void truncate_inode_pages(struct address_space
*, loff_t
);
1154 extern void truncate_inode_pages_range(struct address_space
*,
1155 loff_t lstart
, loff_t lend
);
1157 /* generic vm_area_ops exported for stackable file systems */
1158 extern int filemap_fault(struct vm_area_struct
*, struct vm_fault
*);
1160 /* mm/page-writeback.c */
1161 int write_one_page(struct page
*page
, int wait
);
1164 #define VM_MAX_READAHEAD 128 /* kbytes */
1165 #define VM_MIN_READAHEAD 16 /* kbytes (includes current page) */
1166 #define VM_MAX_CACHE_HIT 256 /* max pages in a row in cache before
1167 * turning readahead off */
1169 int do_page_cache_readahead(struct address_space
*mapping
, struct file
*filp
,
1170 pgoff_t offset
, unsigned long nr_to_read
);
1171 int force_page_cache_readahead(struct address_space
*mapping
, struct file
*filp
,
1172 pgoff_t offset
, unsigned long nr_to_read
);
1173 unsigned long page_cache_readahead(struct address_space
*mapping
,
1174 struct file_ra_state
*ra
,
1177 unsigned long size
);
1178 void handle_ra_miss(struct address_space
*mapping
,
1179 struct file_ra_state
*ra
, pgoff_t offset
);
1180 unsigned long max_sane_readahead(unsigned long nr
);
1182 /* Do stack extension */
1183 extern int expand_stack(struct vm_area_struct
*vma
, unsigned long address
);
1185 extern int expand_upwards(struct vm_area_struct
*vma
, unsigned long address
);
1188 /* Look up the first VMA which satisfies addr < vm_end, NULL if none. */
1189 extern struct vm_area_struct
* find_vma(struct mm_struct
* mm
, unsigned long addr
);
1190 extern struct vm_area_struct
* find_vma_prev(struct mm_struct
* mm
, unsigned long addr
,
1191 struct vm_area_struct
**pprev
);
1193 /* Look up the first VMA which intersects the interval start_addr..end_addr-1,
1194 NULL if none. Assume start_addr < end_addr. */
1195 static inline struct vm_area_struct
* find_vma_intersection(struct mm_struct
* mm
, unsigned long start_addr
, unsigned long end_addr
)
1197 struct vm_area_struct
* vma
= find_vma(mm
,start_addr
);
1199 if (vma
&& end_addr
<= vma
->vm_start
)
1204 static inline unsigned long vma_pages(struct vm_area_struct
*vma
)
1206 return (vma
->vm_end
- vma
->vm_start
) >> PAGE_SHIFT
;
1209 pgprot_t
vm_get_page_prot(unsigned long vm_flags
);
1210 struct vm_area_struct
*find_extend_vma(struct mm_struct
*, unsigned long addr
);
1211 struct page
*vmalloc_to_page(void *addr
);
1212 unsigned long vmalloc_to_pfn(void *addr
);
1213 int remap_pfn_range(struct vm_area_struct
*, unsigned long addr
,
1214 unsigned long pfn
, unsigned long size
, pgprot_t
);
1215 int vm_insert_page(struct vm_area_struct
*, unsigned long addr
, struct page
*);
1216 int vm_insert_pfn(struct vm_area_struct
*vma
, unsigned long addr
,
1219 struct page
*follow_page(struct vm_area_struct
*, unsigned long address
,
1220 unsigned int foll_flags
);
1221 #define FOLL_WRITE 0x01 /* check pte is writable */
1222 #define FOLL_TOUCH 0x02 /* mark page accessed */
1223 #define FOLL_GET 0x04 /* do get_page on page */
1224 #define FOLL_ANON 0x08 /* give ZERO_PAGE if no pgtable */
1226 typedef int (*pte_fn_t
)(pte_t
*pte
, struct page
*pmd_page
, unsigned long addr
,
1228 extern int apply_to_page_range(struct mm_struct
*mm
, unsigned long address
,
1229 unsigned long size
, pte_fn_t fn
, void *data
);
1231 #ifdef CONFIG_PROC_FS
1232 void vm_stat_account(struct mm_struct
*, unsigned long, struct file
*, long);
1234 static inline void vm_stat_account(struct mm_struct
*mm
,
1235 unsigned long flags
, struct file
*file
, long pages
)
1238 #endif /* CONFIG_PROC_FS */
1240 #ifndef CONFIG_DEBUG_PAGEALLOC
1242 kernel_map_pages(struct page
*page
, int numpages
, int enable
) {}
1245 extern struct vm_area_struct
*get_gate_vma(struct task_struct
*tsk
);
1246 #ifdef __HAVE_ARCH_GATE_AREA
1247 int in_gate_area_no_task(unsigned long addr
);
1248 int in_gate_area(struct task_struct
*task
, unsigned long addr
);
1250 int in_gate_area_no_task(unsigned long addr
);
1251 #define in_gate_area(task, addr) ({(void)task; in_gate_area_no_task(addr);})
1252 #endif /* __HAVE_ARCH_GATE_AREA */
1254 int drop_caches_sysctl_handler(struct ctl_table
*, int, struct file
*,
1255 void __user
*, size_t *, loff_t
*);
1256 unsigned long shrink_slab(unsigned long scanned
, gfp_t gfp_mask
,
1257 unsigned long lru_pages
);
1258 void drop_pagecache(void);
1259 void drop_slab(void);
1262 #define randomize_va_space 0
1264 extern int randomize_va_space
;
1267 __attribute__((weak
)) const char *arch_vma_name(struct vm_area_struct
*vma
);
1269 #endif /* __KERNEL__ */
1270 #endif /* _LINUX_MM_H */