LXR linux/include/linux/pagevec.h

   1/*
   2 * include/linux/pagevec.h
   3 *
   4 * In many places it is efficient to batch an operation up against multiple
   5 * pages.  A pagevec is a multipage container which is used for that.
   6 */
   7
   8#ifndef _LINUX_PAGEVEC_H
   9#define _LINUX_PAGEVEC_H
  10
  11/* 14 pointers + two long's align the pagevec structure to a power of two */
  12#define PAGEVEC_SIZE    14
  13
  14struct page;
  15struct address_space;
  16
  17struct pagevec {
  18        unsigned long nr;
  19        unsigned long cold;
  20        struct page *pages[PAGEVEC_SIZE];
  21};
  22
  23void __pagevec_release(struct pagevec *pvec);
  24void __pagevec_lru_add(struct pagevec *pvec);
  25unsigned pagevec_lookup_entries(struct pagevec *pvec,
  26                                struct address_space *mapping,
  27                                pgoff_t start, unsigned nr_entries,
  28                                pgoff_t *indices);
  29void pagevec_remove_exceptionals(struct pagevec *pvec);
  30unsigned pagevec_lookup(struct pagevec *pvec, struct address_space *mapping,
  31                pgoff_t start, unsigned nr_pages);
  32unsigned pagevec_lookup_tag(struct pagevec *pvec,
  33                struct address_space *mapping, pgoff_t *index, int tag,
  34                unsigned nr_pages);
  35
  36static inline void pagevec_init(struct pagevec *pvec, int cold)
  37{
  38        pvec->nr = 0;
  39        pvec->cold = cold;
  40}
  41
  42static inline void pagevec_reinit(struct pagevec *pvec)
  43{
  44        pvec->nr = 0;
  45}
  46
  47static inline unsigned pagevec_count(struct pagevec *pvec)
  48{
  49        return pvec->nr;
  50}
  51
  52static inline unsigned pagevec_space(struct pagevec *pvec)
  53{
  54        return PAGEVEC_SIZE - pvec->nr;
  55}
  56
  57/*
  58 * Add a page to a pagevec.  Returns the number of slots still available.
  59 */
  60static inline unsigned pagevec_add(struct pagevec *pvec, struct page *page)
  61{
  62        pvec->pages[pvec->nr++] = page;
  63        return pagevec_space(pvec);
  64}
  65
  66static inline void pagevec_release(struct pagevec *pvec)
  67{
  68        if (pagevec_count(pvec))
  69                __pagevec_release(pvec);
  70}
  71
  72#endif /* _LINUX_PAGEVEC_H */
  73