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Commit f4e774f5 authored by Johannes Berg's avatar Johannes Berg Committed by David S. Miller
Browse files

average: remove out-of-line implementation 



Since all users are now converted to the inline implementation,
remove the out-of-line implementation entirely.

Signed-off-by: default avatarJohannes Berg <johannes.berg@intel.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 11ab35ed

include/linux/average.h

+0 −24
Original line number Diff line number Diff line
@@ -3,30 +3,6 @@ 


/* 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;

}



#define DECLARE_EWMA(name, _factor, _weight)				\

	struct ewma_##name {						\

		unsigned long internal;					\

lib/Kconfig

+0 −10
Original line number Diff line number Diff line
@@ -460,16 +460,6 @@ config ARCH_HAS_ATOMIC64_DEC_IF_POSITIVE 
config LRU_CACHE

	tristate



config AVERAGE

	bool "Averaging functions"

	help

	  This option is provided for the case where no in-kernel-tree

	  modules require averaging functions, but a module built outside

	  the kernel tree does. Such modules that use library averaging

	  functions require Y here.



	  If unsure, say N.



config CLZ_TAB

	bool

lib/average.c

deleted100644 → 0
+0 −64
Original line number Diff line number Diff line 
/*

 * lib/average.c

 *

 * This source code is licensed under the GNU General Public License,

 * Version 2.  See the file COPYING for more details.

 */



#include <linux/export.h>

#include <linux/average.h>

#include <linux/kernel.h>

#include <linux/bug.h>

#include <linux/log2.h>



/**

 * DOC: Exponentially Weighted Moving Average (EWMA)

 *

 * These are generic functions for calculating Exponentially Weighted Moving

 * Averages (EWMA). We keep a structure with the EWMA parameters and a scaled

 * up internal representation of the average value to prevent rounding errors.

 * The factor for scaling up and the exponential weight (or decay rate) have to

 * be specified thru the init fuction. The structure should not be accessed

 * directly but only thru the helper functions.

 */



/**

 * ewma_init() - Initialize EWMA parameters

 * @avg: Average structure

 * @factor: Factor to use for the scaled up internal value. The maximum value

 *	of averages can be ULONG_MAX/(factor*weight). For performance reasons

 *	factor has to be a power of 2.

 * @weight: Exponential weight, or decay rate. This defines how fast the

 *	influence of older values decreases. For performance reasons weight has

 *	to be a power of 2.

 *

 * Initialize the EWMA parameters for a given struct ewma @avg.

 */

void ewma_init(struct ewma *avg, unsigned long factor, unsigned long weight)

{

	WARN_ON(!is_power_of_2(weight) || !is_power_of_2(factor));



	avg->weight = ilog2(weight);

	avg->factor = ilog2(factor);

	avg->internal = 0;

}

EXPORT_SYMBOL(ewma_init);



/**

 * ewma_add() - Exponentially weighted moving average (EWMA)

 * @avg: Average structure

 * @val: Current value

 *

 * Add a sample to the average.

 */

struct ewma *ewma_add(struct ewma *avg, unsigned long val)

{

	unsigned long internal = ACCESS_ONCE(avg->internal);



	ACCESS_ONCE(avg->internal) = internal ?

		(((internal << avg->weight) - internal) +

			(val << avg->factor)) >> avg->weight :

		(val << avg->factor);

	return avg;

}

EXPORT_SYMBOL(ewma_add);