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| author |   Jens Axboe <jaxboe@fusionio.com> | 2011-03-01 15:04:39 -0500 |
|---|---|---|
| committer | Jens Axboe <jaxboe@fusionio.com> | 2011-03-01 15:04:39 -0500 |
| commit | 6fae9c25134baffbeeb20031479e7ff6f6d8eec0 (patch) | |
| tree | c9ab89992ce5293a43cd455a81dc8a5926a28a5e /include/linux/average.h | |
| parent | block: share request flush fields with elevator_private (diff) | |
| parent | Linux 2.6.38-rc6 (diff) | |
| download | linux-dev-6fae9c25134baffbeeb20031479e7ff6f6d8eec0.tar.xz linux-dev-6fae9c25134baffbeeb20031479e7ff6f6d8eec0.zip | |
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.h | 30 |
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 --- /dev/null +++ b/include/linux/average.h @@ -0,0 +1,30 @@ +#ifndef _LINUX_AVERAGE_H +#define _LINUX_AVERAGE_H + +/* Exponentially weighted moving average (EWMA) */ + +/* For more documentation see lib/average.c */ + +struct ewma { + unsigned long internal; + unsigned long factor; + unsigned long weight; +}; + +extern void ewma_init(struct ewma *avg, unsigned long factor, + unsigned long weight); + +extern struct ewma *ewma_add(struct ewma *avg, unsigned long val); + +/** + * ewma_read() - Get average value + * @avg: Average structure + * + * Returns the average value held in @avg. + */ +static inline unsigned long ewma_read(const struct ewma *avg) +{ + return avg->internal >> avg->factor; +} + +#endif /* _LINUX_AVERAGE_H */ |