include/linux/average.h

   1 #ifndef _LINUX_AVERAGE_H
   2 #define _LINUX_AVERAGE_H
   3
   4 /* Exponentially weighted moving average (EWMA) */
   5
   6 /* For more documentation see lib/average.c */
   7
   8 struct ewma {
   9         unsigned long internal;
  10         unsigned long factor;
  11         unsigned long weight;
  12 };
  13
  14 extern void ewma_init(struct ewma *avg, unsigned long factor,
  15                       unsigned long weight);
  16
  17 extern struct ewma *ewma_add(struct ewma *avg, unsigned long val);
  18
  19 /**
  20  * ewma_read() - Get average value
  21  * @avg: Average structure
  22  *
  23  * Returns the average value held in @avg.
  24  */
  25 static inline unsigned long ewma_read(const struct ewma *avg)
  26 {
  27         return avg->internal >> avg->factor;
  28 }
  29
  30 #endif /* _LINUX_AVERAGE_H */