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 /* 14 pointers + two long's align the pagevec structure to a power of two */
   9 #define PAGEVEC_SIZE    14
  10
  11 struct page;
  12 struct address_space;
  13
  14 struct pagevec {
  15         unsigned long nr;
  16         unsigned long cold;
  17         struct page *pages[PAGEVEC_SIZE];
  18 };
  19
  20 void __pagevec_release(struct pagevec *pvec);
  21 void __pagevec_release_nonlru(struct pagevec *pvec);
  22 void __pagevec_free(struct pagevec *pvec);
  23 void __pagevec_lru_add(struct pagevec *pvec);
  24 void __pagevec_lru_add_active(struct pagevec *pvec);
  25 void pagevec_strip(struct pagevec *pvec);
  26 unsigned pagevec_lookup(struct pagevec *pvec, struct address_space *mapping,
  27                 pgoff_t start, unsigned nr_pages);
  28 unsigned pagevec_lookup_tag(struct pagevec *pvec,
  29                 struct address_space *mapping, pgoff_t *index, int tag,
  30                 unsigned nr_pages);
  31
  32 static inline void pagevec_init(struct pagevec *pvec, int cold)
  33 {
  34         pvec->nr = 0;
  35         pvec->cold = cold;
  36 }
  37
  38 static inline void pagevec_reinit(struct pagevec *pvec)
  39 {
  40         pvec->nr = 0;
  41 }
  42
  43 static inline unsigned pagevec_count(struct pagevec *pvec)
  44 {
  45         return pvec->nr;
  46 }
  47
  48 static inline unsigned pagevec_space(struct pagevec *pvec)
  49 {
  50         return PAGEVEC_SIZE - pvec->nr;
  51 }
  52
  53 /*
  54  * Add a page to a pagevec.  Returns the number of slots still available.
  55  */
  56 static inline unsigned pagevec_add(struct pagevec *pvec, struct page *page)
  57 {
  58         pvec->pages[pvec->nr++] = page;
  59         return pagevec_space(pvec);
  60 }
  61
  62
  63 static inline void pagevec_release(struct pagevec *pvec)
  64 {
  65         if (pagevec_count(pvec))
  66                 __pagevec_release(pvec);
  67 }
  68
  69 static inline void pagevec_release_nonlru(struct pagevec *pvec)
  70 {
  71         if (pagevec_count(pvec))
  72                 __pagevec_release_nonlru(pvec);
  73 }
  74
  75 static inline void pagevec_free(struct pagevec *pvec)
  76 {
  77         if (pagevec_count(pvec))
  78                 __pagevec_free(pvec);
  79 }
  80
  81 static inline void pagevec_lru_add(struct pagevec *pvec)
  82 {
  83         if (pagevec_count(pvec))
  84                 __pagevec_lru_add(pvec);
  85 }