LXR linux-old/include/linux/mm.h

   1#ifndef _LINUX_MM_H
   2#define _LINUX_MM_H
   3
   4#include <linux/sched.h>
   5#include <linux/errno.h>
   6
   7#ifdef __KERNEL__
   8
   9#include <linux/config.h>
  10#include <linux/string.h>
  11#include <linux/list.h>
  12#include <linux/mmzone.h>
  13
  14extern unsigned long max_mapnr;
  15extern unsigned long num_physpages;
  16extern void * high_memory;
  17extern int page_cluster;
  18/* The inactive_clean lists are per zone. */
  19extern struct list_head active_list;
  20extern struct list_head inactive_dirty_list;
  21
  22#include <asm/page.h>
  23#include <asm/pgtable.h>
  24#include <asm/atomic.h>
  25
  26/*
  27 * Linux kernel virtual memory manager primitives.
  28 * The idea being to have a "virtual" mm in the same way
  29 * we have a virtual fs - giving a cleaner interface to the
  30 * mm details, and allowing different kinds of memory mappings
  31 * (from shared memory to executable loading to arbitrary
  32 * mmap() functions).
  33 */
  34
  35/*
  36 * This struct defines a memory VMM memory area. There is one of these
  37 * per VM-area/task.  A VM area is any part of the process virtual memory
  38 * space that has a special rule for the page-fault handlers (ie a shared
  39 * library, the executable area etc).
  40 */
  41struct vm_area_struct {
  42        struct mm_struct * vm_mm;       /* VM area parameters */
  43        unsigned long vm_start;
  44        unsigned long vm_end;
  45
  46        /* linked list of VM areas per task, sorted by address */
  47        struct vm_area_struct *vm_next;
  48
  49        pgprot_t vm_page_prot;
  50        unsigned long vm_flags;
  51
  52        /* AVL tree of VM areas per task, sorted by address */
  53        short vm_avl_height;
  54        struct vm_area_struct * vm_avl_left;
  55        struct vm_area_struct * vm_avl_right;
  56
  57        /* For areas with an address space and backing store,
  58         * one of the address_space->i_mmap{,shared} lists,
  59         * for shm areas, the list of attaches, otherwise unused.
  60         */
  61        struct vm_area_struct *vm_next_share;
  62        struct vm_area_struct **vm_pprev_share;
  63
  64        struct vm_operations_struct * vm_ops;
  65        unsigned long vm_pgoff;         /* offset in PAGE_SIZE units, *not* PAGE_CACHE_SIZE */
  66        struct file * vm_file;
  67        unsigned long vm_raend;
  68        void * vm_private_data;         /* was vm_pte (shared mem) */
  69};
  70
  71/*
  72 * vm_flags..
  73 */
  74#define VM_READ         0x00000001      /* currently active flags */
  75#define VM_WRITE        0x00000002
  76#define VM_EXEC         0x00000004
  77#define VM_SHARED       0x00000008
  78
  79#define VM_MAYREAD      0x00000010      /* limits for mprotect() etc */
  80#define VM_MAYWRITE     0x00000020
  81#define VM_MAYEXEC      0x00000040
  82#define VM_MAYSHARE     0x00000080
  83
  84#define VM_GROWSDOWN    0x00000100      /* general info on the segment */
  85#define VM_GROWSUP      0x00000200
  86#define VM_SHM          0x00000400      /* shared memory area, don't swap out */
  87#define VM_DENYWRITE    0x00000800      /* ETXTBSY on write attempts.. */
  88
  89#define VM_EXECUTABLE   0x00001000
  90#define VM_LOCKED       0x00002000
  91#define VM_IO           0x00004000      /* Memory mapped I/O or similar */
  92
  93#define VM_SEQ_READ     0x00008000      /* App will access data sequentially */
  94#define VM_RAND_READ    0x00010000      /* App will not benefit from clustered reads */
  95
  96#define VM_DONTCOPY     0x00020000      /* Do not copy this vma on fork */
  97#define VM_DONTEXPAND   0x00040000      /* Cannot expand with mremap() */
  98#define VM_RESERVED     0x00080000      /* Don't unmap it from swap_out */
  99
 100#define VM_STACK_FLAGS  0x00000177
 101
 102#define VM_READHINTMASK                 (VM_SEQ_READ | VM_RAND_READ)
 103#define VM_ClearReadHint(v)             (v)->vm_flags &= ~VM_READHINTMASK
 104#define VM_NormalReadHint(v)            (!((v)->vm_flags & VM_READHINTMASK))
 105#define VM_SequentialReadHint(v)        ((v)->vm_flags & VM_SEQ_READ)
 106#define VM_RandomReadHint(v)            ((v)->vm_flags & VM_RAND_READ)
 107
 108/*
 109 * mapping from the currently active vm_flags protection bits (the
 110 * low four bits) to a page protection mask..
 111 */
 112extern pgprot_t protection_map[16];
 113
 114
 115/*
 116 * These are the virtual MM functions - opening of an area, closing and
 117 * unmapping it (needed to keep files on disk up-to-date etc), pointer
 118 * to the functions called when a no-page or a wp-page exception occurs. 
 119 */
 120struct vm_operations_struct {
 121        void (*open)(struct vm_area_struct * area);
 122        void (*close)(struct vm_area_struct * area);
 123        struct page * (*nopage)(struct vm_area_struct * area, unsigned long address, int write_access);
 124};
 125
 126/*
 127 * Try to keep the most commonly accessed fields in single cache lines
 128 * here (16 bytes or greater).  This ordering should be particularly
 129 * beneficial on 32-bit processors.
 130 *
 131 * The first line is data used in page cache lookup, the second line
 132 * is used for linear searches (eg. clock algorithm scans). 
 133 */
 134typedef struct page {
 135        struct list_head list;
 136        struct address_space *mapping;
 137        unsigned long index;
 138        struct page *next_hash;
 139        atomic_t count;
 140        unsigned long flags;    /* atomic flags, some possibly updated asynchronously */
 141        struct list_head lru;
 142        unsigned long age;
 143        wait_queue_head_t wait;
 144        struct page **pprev_hash;
 145        struct buffer_head * buffers;
 146        void *virtual; /* non-NULL if kmapped */
 147        struct zone_struct *zone;
 148} mem_map_t;
 149
 150#define get_page(p)             atomic_inc(&(p)->count)
 151#define put_page(p)             __free_page(p)
 152#define put_page_testzero(p)    atomic_dec_and_test(&(p)->count)
 153#define page_count(p)           atomic_read(&(p)->count)
 154#define set_page_count(p,v)     atomic_set(&(p)->count, v)
 155
 156/* Page flag bit values */
 157#define PG_locked                0
 158#define PG_error                 1
 159#define PG_referenced            2
 160#define PG_uptodate              3
 161#define PG_dirty                 4
 162#define PG_decr_after            5
 163#define PG_active                6
 164#define PG_inactive_dirty        7
 165#define PG_slab                  8
 166#define PG_swap_cache            9
 167#define PG_skip                 10
 168#define PG_inactive_clean       11
 169#define PG_highmem              12
 170                                /* bits 21-29 unused */
 171#define PG_arch_1               30
 172#define PG_reserved             31
 173
 174/* Make it prettier to test the above... */
 175#define Page_Uptodate(page)     test_bit(PG_uptodate, &(page)->flags)
 176#define SetPageUptodate(page)   set_bit(PG_uptodate, &(page)->flags)
 177#define ClearPageUptodate(page) clear_bit(PG_uptodate, &(page)->flags)
 178#define PageDirty(page)         test_bit(PG_dirty, &(page)->flags)
 179#define SetPageDirty(page)      set_bit(PG_dirty, &(page)->flags)
 180#define ClearPageDirty(page)    clear_bit(PG_dirty, &(page)->flags)
 181#define PageLocked(page)        test_bit(PG_locked, &(page)->flags)
 182#define LockPage(page)          set_bit(PG_locked, &(page)->flags)
 183#define TryLockPage(page)       test_and_set_bit(PG_locked, &(page)->flags)
 184
 185extern void __set_page_dirty(struct page *);
 186
 187static inline void set_page_dirty(struct page * page)
 188{
 189        if (!test_and_set_bit(PG_dirty, &page->flags))
 190                __set_page_dirty(page);
 191}
 192
 193/*
 194 * The first mb is necessary to safely close the critical section opened by the
 195 * TryLockPage(), the second mb is necessary to enforce ordering between
 196 * the clear_bit and the read of the waitqueue (to avoid SMP races with a
 197 * parallel wait_on_page).
 198 */
 199#define UnlockPage(page)        do { \
 200                                        smp_mb__before_clear_bit(); \
 201                                        if (!test_and_clear_bit(PG_locked, &(page)->flags)) BUG(); \
 202                                        smp_mb__after_clear_bit(); \
 203                                        if (waitqueue_active(&page->wait)) \
 204                                                wake_up(&page->wait); \
 205                                } while (0)
 206#define PageError(page)         test_bit(PG_error, &(page)->flags)
 207#define SetPageError(page)      set_bit(PG_error, &(page)->flags)
 208#define ClearPageError(page)    clear_bit(PG_error, &(page)->flags)
 209#define PageReferenced(page)    test_bit(PG_referenced, &(page)->flags)
 210#define SetPageReferenced(page) set_bit(PG_referenced, &(page)->flags)
 211#define ClearPageReferenced(page)       clear_bit(PG_referenced, &(page)->flags)
 212#define PageTestandClearReferenced(page)        test_and_clear_bit(PG_referenced, &(page)->flags)
 213#define PageDecrAfter(page)     test_bit(PG_decr_after, &(page)->flags)
 214#define SetPageDecrAfter(page)  set_bit(PG_decr_after, &(page)->flags)
 215#define PageTestandClearDecrAfter(page) test_and_clear_bit(PG_decr_after, &(page)->flags)
 216#define PageSlab(page)          test_bit(PG_slab, &(page)->flags)
 217#define PageSwapCache(page)     test_bit(PG_swap_cache, &(page)->flags)
 218#define PageReserved(page)      test_bit(PG_reserved, &(page)->flags)
 219
 220#define PageSetSlab(page)       set_bit(PG_slab, &(page)->flags)
 221#define PageSetSwapCache(page)  set_bit(PG_swap_cache, &(page)->flags)
 222
 223#define PageTestandSetSwapCache(page)   test_and_set_bit(PG_swap_cache, &(page)->flags)
 224
 225#define PageClearSlab(page)             clear_bit(PG_slab, &(page)->flags)
 226#define PageClearSwapCache(page)        clear_bit(PG_swap_cache, &(page)->flags)
 227
 228#define PageTestandClearSwapCache(page) test_and_clear_bit(PG_swap_cache, &(page)->flags)
 229
 230#define PageActive(page)        test_bit(PG_active, &(page)->flags)
 231#define SetPageActive(page)     set_bit(PG_active, &(page)->flags)
 232#define ClearPageActive(page)   clear_bit(PG_active, &(page)->flags)
 233
 234#define PageInactiveDirty(page) test_bit(PG_inactive_dirty, &(page)->flags)
 235#define SetPageInactiveDirty(page)      set_bit(PG_inactive_dirty, &(page)->flags)
 236#define ClearPageInactiveDirty(page)    clear_bit(PG_inactive_dirty, &(page)->flags)
 237
 238#define PageInactiveClean(page) test_bit(PG_inactive_clean, &(page)->flags)
 239#define SetPageInactiveClean(page)      set_bit(PG_inactive_clean, &(page)->flags)
 240#define ClearPageInactiveClean(page)    clear_bit(PG_inactive_clean, &(page)->flags)
 241
 242#ifdef CONFIG_HIGHMEM
 243#define PageHighMem(page)               test_bit(PG_highmem, &(page)->flags)
 244#else
 245#define PageHighMem(page)               0 /* needed to optimize away at compile time */
 246#endif
 247
 248#define SetPageReserved(page)           set_bit(PG_reserved, &(page)->flags)
 249#define ClearPageReserved(page)         clear_bit(PG_reserved, &(page)->flags)
 250
 251/*
 252 * Error return values for the *_nopage functions
 253 */
 254#define NOPAGE_SIGBUS   (NULL)
 255#define NOPAGE_OOM      ((struct page *) (-1))
 256
 257
 258/*
 259 * Various page->flags bits:
 260 *
 261 * PG_reserved is set for a page which must never be accessed (which
 262 * may not even be present).
 263 *
 264 * PG_DMA has been removed, page->zone now tells exactly wether the
 265 * page is suited to do DMAing into.
 266 *
 267 * Multiple processes may "see" the same page. E.g. for untouched
 268 * mappings of /dev/null, all processes see the same page full of
 269 * zeroes, and text pages of executables and shared libraries have
 270 * only one copy in memory, at most, normally.
 271 *
 272 * For the non-reserved pages, page->count denotes a reference count.
 273 *   page->count == 0 means the page is free.
 274 *   page->count == 1 means the page is used for exactly one purpose
 275 *   (e.g. a private data page of one process).
 276 *
 277 * A page may be used for kmalloc() or anyone else who does a
 278 * __get_free_page(). In this case the page->count is at least 1, and
 279 * all other fields are unused but should be 0 or NULL. The
 280 * management of this page is the responsibility of the one who uses
 281 * it.
 282 *
 283 * The other pages (we may call them "process pages") are completely
 284 * managed by the Linux memory manager: I/O, buffers, swapping etc.
 285 * The following discussion applies only to them.
 286 *
 287 * A page may belong to an inode's memory mapping. In this case,
 288 * page->inode is the pointer to the inode, and page->offset is the
 289 * file offset of the page (not necessarily a multiple of PAGE_SIZE).
 290 *
 291 * A page may have buffers allocated to it. In this case,
 292 * page->buffers is a circular list of these buffer heads. Else,
 293 * page->buffers == NULL.
 294 *
 295 * For pages belonging to inodes, the page->count is the number of
 296 * attaches, plus 1 if buffers are allocated to the page.
 297 *
 298 * All pages belonging to an inode make up a doubly linked list
 299 * inode->i_pages, using the fields page->next and page->prev. (These
 300 * fields are also used for freelist management when page->count==0.)
 301 * There is also a hash table mapping (inode,offset) to the page
 302 * in memory if present. The lists for this hash table use the fields
 303 * page->next_hash and page->pprev_hash.
 304 *
 305 * All process pages can do I/O:
 306 * - inode pages may need to be read from disk,
 307 * - inode pages which have been modified and are MAP_SHARED may need
 308 *   to be written to disk,
 309 * - private pages which have been modified may need to be swapped out
 310 *   to swap space and (later) to be read back into memory.
 311 * During disk I/O, PG_locked is used. This bit is set before I/O
 312 * and reset when I/O completes. page->wait is a wait queue of all
 313 * tasks waiting for the I/O on this page to complete.
 314 * PG_uptodate tells whether the page's contents is valid.
 315 * When a read completes, the page becomes uptodate, unless a disk I/O
 316 * error happened.
 317 *
 318 * For choosing which pages to swap out, inode pages carry a
 319 * PG_referenced bit, which is set any time the system accesses
 320 * that page through the (inode,offset) hash table.
 321 *
 322 * PG_skip is used on sparc/sparc64 architectures to "skip" certain
 323 * parts of the address space.
 324 *
 325 * PG_error is set to indicate that an I/O error occurred on this page.
 326 *
 327 * PG_arch_1 is an architecture specific page state bit.  The generic
 328 * code guarentees that this bit is cleared for a page when it first
 329 * is entered into the page cache.
 330 */
 331
 332extern mem_map_t * mem_map;
 333
 334/*
 335 * There is only one page-allocator function, and two main namespaces to
 336 * it. The alloc_page*() variants return 'struct page *' and as such
 337 * can allocate highmem pages, the *get*page*() variants return
 338 * virtual kernel addresses to the allocated page(s).
 339 */
 340extern struct page * FASTCALL(__alloc_pages(zonelist_t *zonelist, unsigned long order));
 341extern struct page * alloc_pages_node(int nid, int gfp_mask, unsigned long order);
 342
 343#ifndef CONFIG_DISCONTIGMEM
 344static inline struct page * alloc_pages(int gfp_mask, unsigned long order)
 345{
 346        /*
 347         * Gets optimized away by the compiler.
 348         */
 349        if (order >= MAX_ORDER)
 350                return NULL;
 351        return __alloc_pages(contig_page_data.node_zonelists+(gfp_mask), order);
 352}
 353#else /* !CONFIG_DISCONTIGMEM */
 354extern struct page * alloc_pages(int gfp_mask, unsigned long order);
 355#endif /* !CONFIG_DISCONTIGMEM */
 356
 357#define alloc_page(gfp_mask) alloc_pages(gfp_mask, 0)
 358
 359extern unsigned long FASTCALL(__get_free_pages(int gfp_mask, unsigned long order));
 360extern unsigned long FASTCALL(get_zeroed_page(int gfp_mask));
 361
 362#define __get_free_page(gfp_mask) \
 363                __get_free_pages((gfp_mask),0)
 364
 365#define __get_dma_pages(gfp_mask, order) \
 366                __get_free_pages((gfp_mask) | GFP_DMA,(order))
 367
 368/*
 369 * The old interface name will be removed in 2.5:
 370 */
 371#define get_free_page get_zeroed_page
 372
 373/*
 374 * There is only one 'core' page-freeing function.
 375 */
 376extern void FASTCALL(__free_pages(struct page *page, unsigned long order));
 377extern void FASTCALL(free_pages(unsigned long addr, unsigned long order));
 378
 379#define __free_page(page) __free_pages((page), 0)
 380#define free_page(addr) free_pages((addr),0)
 381
 382extern void show_free_areas(void);
 383extern void show_free_areas_node(pg_data_t *pgdat);
 384
 385extern void clear_page_tables(struct mm_struct *, unsigned long, int);
 386
 387struct page * shmem_nopage(struct vm_area_struct * vma, unsigned long address, int no_share);
 388struct file *shmem_file_setup(char * name, loff_t size);
 389extern void shmem_lock(struct file * file, int lock);
 390extern int shmem_zero_setup(struct vm_area_struct *);
 391
 392extern void zap_page_range(struct mm_struct *mm, unsigned long address, unsigned long size);
 393extern int copy_page_range(struct mm_struct *dst, struct mm_struct *src, struct vm_area_struct *vma);
 394extern int remap_page_range(unsigned long from, unsigned long to, unsigned long size, pgprot_t prot);
 395extern int zeromap_page_range(unsigned long from, unsigned long size, pgprot_t prot);
 396
 397extern void vmtruncate(struct inode * inode, loff_t offset);
 398extern int handle_mm_fault(struct mm_struct *mm,struct vm_area_struct *vma, unsigned long address, int write_access);
 399extern int make_pages_present(unsigned long addr, unsigned long end);
 400extern int access_process_vm(struct task_struct *tsk, unsigned long addr, void *buf, int len, int write);
 401extern int ptrace_readdata(struct task_struct *tsk, unsigned long src, char *dst, int len);
 402extern int ptrace_writedata(struct task_struct *tsk, char * src, unsigned long dst, int len);
 403
 404extern int pgt_cache_water[2];
 405extern int check_pgt_cache(void);
 406
 407extern void free_area_init(unsigned long * zones_size);
 408extern void free_area_init_node(int nid, pg_data_t *pgdat, struct page *pmap,
 409        unsigned long * zones_size, unsigned long zone_start_paddr, 
 410        unsigned long *zholes_size);
 411extern void mem_init(void);
 412extern void show_mem(void);
 413extern void si_meminfo(struct sysinfo * val);
 414extern void swapin_readahead(swp_entry_t);
 415
 416/* mmap.c */
 417extern void lock_vma_mappings(struct vm_area_struct *);
 418extern void unlock_vma_mappings(struct vm_area_struct *);
 419extern void insert_vm_struct(struct mm_struct *, struct vm_area_struct *);
 420extern void __insert_vm_struct(struct mm_struct *, struct vm_area_struct *);
 421extern void build_mmap_avl(struct mm_struct *);
 422extern void exit_mmap(struct mm_struct *);
 423extern unsigned long get_unmapped_area(unsigned long, unsigned long);
 424
 425extern unsigned long do_mmap_pgoff(struct file *file, unsigned long addr,
 426        unsigned long len, unsigned long prot,
 427        unsigned long flag, unsigned long pgoff);
 428
 429static inline unsigned long do_mmap(struct file *file, unsigned long addr,
 430        unsigned long len, unsigned long prot,
 431        unsigned long flag, unsigned long offset)
 432{
 433        unsigned long ret = -EINVAL;
 434        if ((offset + PAGE_ALIGN(len)) < offset)
 435                goto out;
 436        if (!(offset & ~PAGE_MASK))
 437                ret = do_mmap_pgoff(file, addr, len, prot, flag, offset >> PAGE_SHIFT);
 438out:
 439        return ret;
 440}
 441
 442extern int do_munmap(struct mm_struct *, unsigned long, size_t);
 443
 444extern unsigned long do_brk(unsigned long, unsigned long);
 445
 446struct zone_t;
 447/* filemap.c */
 448extern void remove_inode_page(struct page *);
 449extern unsigned long page_unuse(struct page *);
 450extern void truncate_inode_pages(struct address_space *, loff_t);
 451
 452/* generic vm_area_ops exported for stackable file systems */
 453extern int filemap_sync(struct vm_area_struct *, unsigned long, size_t, unsigned int);
 454extern struct page *filemap_nopage(struct vm_area_struct *, unsigned long, int);
 455
 456/*
 457 * GFP bitmasks..
 458 */
 459#define __GFP_WAIT      0x01
 460#define __GFP_HIGH      0x02
 461#define __GFP_IO        0x04
 462#define __GFP_DMA       0x08
 463#ifdef CONFIG_HIGHMEM
 464#define __GFP_HIGHMEM   0x10
 465#else
 466#define __GFP_HIGHMEM   0x0 /* noop */
 467#endif
 468#define __GFP_VM        0x20
 469
 470
 471#define GFP_BUFFER      (__GFP_HIGH | __GFP_WAIT)
 472#define GFP_ATOMIC      (__GFP_HIGH)
 473#define GFP_USER        (             __GFP_WAIT | __GFP_IO)
 474#define GFP_HIGHUSER    (             __GFP_WAIT | __GFP_IO | __GFP_HIGHMEM)
 475#define GFP_KERNEL      (__GFP_HIGH | __GFP_WAIT | __GFP_IO)
 476#define GFP_NFS         (__GFP_HIGH | __GFP_WAIT | __GFP_IO)
 477#define GFP_KSWAPD      (                          __GFP_IO)
 478
 479/* Flag - indicates that the buffer will be suitable for DMA.  Ignored on some
 480   platforms, used as appropriate on others */
 481
 482#define GFP_DMA         __GFP_DMA
 483
 484/* Flag - indicates that the buffer can be taken from high memory which is not
 485   permanently mapped by the kernel */
 486
 487#define GFP_HIGHMEM     __GFP_HIGHMEM
 488
 489/* vma is the first one with  address < vma->vm_end,
 490 * and even  address < vma->vm_start. Have to extend vma. */
 491static inline int expand_stack(struct vm_area_struct * vma, unsigned long address)
 492{
 493        unsigned long grow;
 494
 495        address &= PAGE_MASK;
 496        grow = (vma->vm_start - address) >> PAGE_SHIFT;
 497        if (vma->vm_end - address > current->rlim[RLIMIT_STACK].rlim_cur ||
 498            ((vma->vm_mm->total_vm + grow) << PAGE_SHIFT) > current->rlim[RLIMIT_AS].rlim_cur)
 499                return -ENOMEM;
 500        vma->vm_start = address;
 501        vma->vm_pgoff -= grow;
 502        vma->vm_mm->total_vm += grow;
 503        if (vma->vm_flags & VM_LOCKED)
 504                vma->vm_mm->locked_vm += grow;
 505        return 0;
 506}
 507
 508/* Look up the first VMA which satisfies  addr < vm_end,  NULL if none. */
 509extern struct vm_area_struct * find_vma(struct mm_struct * mm, unsigned long addr);
 510extern struct vm_area_struct * find_vma_prev(struct mm_struct * mm, unsigned long addr,
 511                                             struct vm_area_struct **pprev);
 512
 513/* Look up the first VMA which intersects the interval start_addr..end_addr-1,
 514   NULL if none.  Assume start_addr < end_addr. */
 515static inline struct vm_area_struct * find_vma_intersection(struct mm_struct * mm, unsigned long start_addr, unsigned long end_addr)
 516{
 517        struct vm_area_struct * vma = find_vma(mm,start_addr);
 518
 519        if (vma && end_addr <= vma->vm_start)
 520                vma = NULL;
 521        return vma;
 522}
 523
 524extern struct vm_area_struct *find_extend_vma(struct mm_struct *mm, unsigned long addr);
 525
 526#define buffer_under_min()      (atomic_read(&buffermem_pages) * 100 < \
 527                                buffer_mem.min_percent * num_physpages)
 528#define pgcache_under_min()     (atomic_read(&page_cache_size) * 100 < \
 529                                page_cache.min_percent * num_physpages)
 530
 531#endif /* __KERNEL__ */
 532
 533#endif
 534