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authorJens Axboe <jaxboe@fusionio.com>2011-03-01 15:04:39 -0500
committerJens Axboe <jaxboe@fusionio.com>2011-03-01 15:04:39 -0500
commit6fae9c25134baffbeeb20031479e7ff6f6d8eec0 (patch)
treec9ab89992ce5293a43cd455a81dc8a5926a28a5e /include/linux/average.h
parentc186794dbb466b45cf40f942f2d09d6d5b4b0e42 (diff)
parentf5412be599602124d2bdd49947b231dd77c0bf99 (diff)
Merge commit 'v2.6.38-rc6' into for-2.6.39/core
Conflicts: block/cfq-iosched.c Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
Diffstat (limited to 'include/linux/average.h')
-rw-r--r--include/linux/average.h30
1 files changed, 30 insertions, 0 deletions
diff --git a/include/linux/average.h b/include/linux/average.h
new file mode 100644
index 000000000000..c6028fd742c1
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@@ -0,0 +1,30 @@
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
8struct ewma {
9 unsigned long internal;
10 unsigned long factor;
11 unsigned long weight;
12};
13
14extern void ewma_init(struct ewma *avg, unsigned long factor,
15 unsigned long weight);
16
17extern 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 */
25static inline unsigned long ewma_read(const struct ewma *avg)
26{
27 return avg->internal >> avg->factor;
28}
29
30#endif /* _LINUX_AVERAGE_H */