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_release_nonlru(struct pagevec *pvec);
  25 void __pagevec_free(struct pagevec *pvec);
  26 void ____pagevec_lru_add(struct pagevec *pvec, enum lru_list lru);
  27 void pagevec_strip(struct pagevec *pvec);
  28 void pagevec_swap_free(struct pagevec *pvec);
  29 unsigned pagevec_lookup(struct pagevec *pvec, struct address_space *mapping,
  30                 pgoff_t start, unsigned nr_pages);
  31 unsigned pagevec_lookup_tag(struct pagevec *pvec,
  32                 struct address_space *mapping, pgoff_t *index, int tag,
  33                 unsigned nr_pages);
  34
  35 static inline void pagevec_init(struct pagevec *pvec, int cold)
  36 {
  37         pvec->nr = 0;
  38         pvec->cold = cold;
  39 }
  40
  41 static inline void pagevec_reinit(struct pagevec *pvec)
  42 {
  43         pvec->nr = 0;
  44 }
  45
  46 static inline unsigned pagevec_count(struct pagevec *pvec)
  47 {
  48         return pvec->nr;
  49 }
  50
  51 static inline unsigned pagevec_space(struct pagevec *pvec)
  52 {
  53         return PAGEVEC_SIZE - pvec->nr;
  54 }
  55
  56 /*
  57  * Add a page to a pagevec.  Returns the number of slots still available.
  58  */
  59 static inline unsigned pagevec_add(struct pagevec *pvec, struct page *page)
  60 {
  61         pvec->pages[pvec->nr++] = page;
  62         return pagevec_space(pvec);
  63 }
  64
  65
  66 static inline void pagevec_release(struct pagevec *pvec)
  67 {
  68         if (pagevec_count(pvec))
  69                 __pagevec_release(pvec);
  70 }
  71
  72 static inline void pagevec_release_nonlru(struct pagevec *pvec)
  73 {
  74         if (pagevec_count(pvec))
  75                 __pagevec_release_nonlru(pvec);
  76 }
  77
  78 static inline void pagevec_free(struct pagevec *pvec)
  79 {
  80         if (pagevec_count(pvec))
  81                 __pagevec_free(pvec);
  82 }
  83
  84 static inline void __pagevec_lru_add(struct pagevec *pvec)
  85 {
  86         ____pagevec_lru_add(pvec, LRU_INACTIVE);
  87 }
  88
  89 static inline void __pagevec_lru_add_active(struct pagevec *pvec)
  90 {
  91         ____pagevec_lru_add(pvec, LRU_ACTIVE);
  92 }
  93
  94 static inline void pagevec_lru_add(struct pagevec *pvec)
  95 {
  96         if (pagevec_count(pvec))
  97                 __pagevec_lru_add(pvec);
  98 }
  99
 100 #endif /* _LINUX_PAGEVEC_H */