| /* 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_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) |
| { |
| unsigned long flags; |
| |
| local_irq_save(flags); |
| __fprop_add_percpu(p, pl, 1); |
| local_irq_restore(flags); |
| } |
| |
| #endif |