104 lines
2.8 KiB
C
104 lines
2.8 KiB
C
/* SPDX-License-Identifier: GPL-2.0 */
|
|
/*
|
|
* Floating proportions with flexible aging period
|
|
*
|
|
* Copyright (C) 2011, SUSE, Jan Kara <jack@suse.cz>
|
|
*/
|
|
|
|
#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 10
|
|
#define FPROP_FRAC_BASE (1UL << FPROP_FRAC_SHIFT)
|
|
|
|
/*
|
|
* ---- Global proportion definitions ----
|
|
*/
|
|
struct fprop_global {
|
|
/* Number of events in the current period */
|
|
struct percpu_counter events;
|
|
/* Current period */
|
|
unsigned int period;
|
|
/* Synchronization with period transitions */
|
|
seqcount_t sequence;
|
|
};
|
|
|
|
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);
|
|
|
|
/*
|
|
* ---- SINGLE ----
|
|
*/
|
|
struct fprop_local_single {
|
|
/* the local events counter */
|
|
unsigned long events;
|
|
/* Period in which we last updated events */
|
|
unsigned int period;
|
|
raw_spinlock_t lock; /* Protect period and numerator */
|
|
};
|
|
|
|
#define INIT_FPROP_LOCAL_SINGLE(name) \
|
|
{ .lock = __RAW_SPIN_LOCK_UNLOCKED(name.lock), \
|
|
}
|
|
|
|
int fprop_local_init_single(struct fprop_local_single *pl);
|
|
void fprop_local_destroy_single(struct fprop_local_single *pl);
|
|
void __fprop_inc_single(struct fprop_global *p, struct fprop_local_single *pl);
|
|
void fprop_fraction_single(struct fprop_global *p,
|
|
struct fprop_local_single *pl, unsigned long *numerator,
|
|
unsigned long *denominator);
|
|
|
|
static inline
|
|
void fprop_inc_single(struct fprop_global *p, struct fprop_local_single *pl)
|
|
{
|
|
unsigned long flags;
|
|
|
|
local_irq_save(flags);
|
|
__fprop_inc_single(p, pl);
|
|
local_irq_restore(flags);
|
|
}
|
|
|
|
/*
|
|
* ---- PERCPU ----
|
|
*/
|
|
struct fprop_local_percpu {
|
|
/* the local events counter */
|
|
struct percpu_counter events;
|
|
/* Period in which we last updated events */
|
|
unsigned int period;
|
|
raw_spinlock_t lock; /* Protect period and numerator */
|
|
};
|
|
|
|
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_inc_percpu(struct fprop_global *p, struct fprop_local_percpu *pl);
|
|
void __fprop_inc_percpu_max(struct fprop_global *p, struct fprop_local_percpu *pl,
|
|
int max_frac);
|
|
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)
|
|
{
|
|
unsigned long flags;
|
|
|
|
local_irq_save(flags);
|
|
__fprop_inc_percpu(p, pl);
|
|
local_irq_restore(flags);
|
|
}
|
|
|
|
#endif
|