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
  14 struct page;
  15 struct address_space;
  16
  17 struct pagevec {
  18         unsigned long nr;
  19         unsigned long cold;
  20         struct page *pages[PAGEVEC_SIZE];
  21 };
  22
  23 void __pagevec_release(struct pagevec *pvec);
  24 void __pagevec_lru_add(struct pagevec *pvec);
  25 unsigned pagevec_lookup_entries(struct pagevec *pvec,
  26                                 struct address_space *mapping,
  27                                 pgoff_t start, unsigned nr_entries,
  28                                 pgoff_t *indices);
  29 void pagevec_remove_exceptionals(struct pagevec *pvec);
  30 unsigned pagevec_lookup(struct pagevec *pvec, struct address_space *mapping,
  31                 pgoff_t start, unsigned nr_pages);
  32 unsigned pagevec_lookup_tag(struct pagevec *pvec,
  33                 struct address_space *mapping, pgoff_t *index, int tag,
  34                 unsigned nr_pages);
  35
  36 static inline void pagevec_init(struct pagevec *pvec, int cold)
  37 {
  38         pvec->nr = 0;
  39         pvec->cold = cold;
  40 }
  41
  42 static inline void pagevec_reinit(struct pagevec *pvec)
  43 {
  44         pvec->nr = 0;
  45 }
  46
  47 static inline unsigned pagevec_count(struct pagevec *pvec)
  48 {
  49         return pvec->nr;
  50 }
  51
  52 static 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  */
  60 static inline unsigned pagevec_add(struct pagevec *pvec, struct page *page)
  61 {
  62         pvec->pages[pvec->nr++] = page;
  63         return pagevec_space(pvec);
  64 }
  65
  66 static inline void pagevec_release(struct pagevec *pvec)
  67 {
  68         if (pagevec_count(pvec))
  69                 __pagevec_release(pvec);
  70 }
  71
  72 #endif /* _LINUX_PAGEVEC_H */