linux/include/linux/flex_proportions.h

/* SPDX-License-Identifier: GPL-2.0 */
/*
 * Floating proportions with flexible aging period
 *
 *  Copyright (C) 2011, SUSE, Jan Kara <[email protected]>
 */

#ifndef _LINUX_FLEX_PROPORTIONS_H
#define _LINUX_FLEX_PROPORTIONS_H

#include <linux/percpu_counter.h>
#include <linux/spinlock.h>
#include <linux/seqlock.h>
#include <linux/gfp.h>

/*
 * When maximum proportion of some event type is specified, this is the
 * precision with which we allow limitting. Note that this creates an upper
 * bound on the number of events per period like
 *   ULLONG_MAX >> FPROP_FRAC_SHIFT.
 */
#define FPROP_FRAC_SHIFT …
#define FPROP_FRAC_BASE …

/*
 * ---- Global proportion definitions ----
 */
struct fprop_global { … };

int fprop_global_init(struct fprop_global *p, gfp_t gfp);
void fprop_global_destroy(struct fprop_global *p);
bool fprop_new_period(struct fprop_global *p, int periods);

/*
 * ---- PERCPU ----
 */
struct fprop_local_percpu { … };

int fprop_local_init_percpu(struct fprop_local_percpu *pl, gfp_t gfp);
void fprop_local_destroy_percpu(struct fprop_local_percpu *pl);
void __fprop_add_percpu(struct fprop_global *p, struct fprop_local_percpu *pl,
		long nr);
void __fprop_add_percpu_max(struct fprop_global *p,
		struct fprop_local_percpu *pl, int max_frac, long nr);
void fprop_fraction_percpu(struct fprop_global *p,
	struct fprop_local_percpu *pl, unsigned long *numerator,
	unsigned long *denominator);

static inline
void fprop_inc_percpu(struct fprop_global *p, struct fprop_local_percpu *pl)
{ … }

#endif