| Bruno Randolf | c5485a7 | 2010-11-16 10:58:37 +0900 | [diff] [blame] | 1 | #ifndef _LINUX_AVERAGE_H |
| 2 | #define _LINUX_AVERAGE_H |
| 3 | |
| 4 | #include <linux/kernel.h> |
| 5 | |
| 6 | /* Exponentially weighted moving average (EWMA) */ |
| 7 | |
| 8 | /* For more documentation see lib/average.c */ |
| 9 | |
| 10 | struct ewma { |
| 11 | unsigned long internal; |
| 12 | unsigned long factor; |
| 13 | unsigned long weight; |
| 14 | }; |
| 15 | |
| 16 | extern void ewma_init(struct ewma *avg, unsigned long factor, |
| 17 | unsigned long weight); |
| 18 | |
| 19 | extern struct ewma *ewma_add(struct ewma *avg, unsigned long val); |
| 20 | |
| 21 | /** |
| 22 | * ewma_read() - Get average value |
| 23 | * @avg: Average structure |
| 24 | * |
| 25 | * Returns the average value held in @avg. |
| 26 | */ |
| 27 | static inline unsigned long ewma_read(const struct ewma *avg) |
| 28 | { |
| 29 | return DIV_ROUND_CLOSEST(avg->internal, avg->factor); |
| 30 | } |
| 31 | |
| 32 | #endif /* _LINUX_AVERAGE_H */ |