2 Commits

Author	SHA1	Message	Date
Bruno Randolf	af55688435	lib: Improve EWMA efficiency by using bitshifts ... Using bitshifts instead of division and multiplication should improve performance. That requires weight and factor to be powers of two, but i think this is something we can live with. Thanks to Peter Zijlstra for the improved formula! Signed-off-by: Bruno Randolf <br1@einfach.org> -- v2: use log2.h functions Signed-off-by: John W. Linville <linville@tuxdriver.com>	2010-12-06 15:58:43 -05:00
Bruno Randolf	c5485a7e75	lib: Add generic exponentially weighted moving average (EWMA) function ... This adds generic functions for calculating Exponentially Weighted Moving Averages (EWMA). This implementation makes use of a structure which keeps the EWMA parameters and a scaled up internal representation to reduce rounding errors. The original idea for this implementation came from the rt2x00 driver (rt2x00link.c). I would like to use it in several places in the mac80211 and ath5k code and I hope it can be useful in many other places in the kernel code. Signed-off-by: Bruno Randolf <br1@einfach.org> Reviewed-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Signed-off-by: John W. Linville <linville@tuxdriver.com>	2010-11-18 14:21:52 -05:00