xref: /linux-6.15/include/linux/average.h (revision c5485a7e)
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 */
33