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b2441318 | 1 | /* SPDX-License-Identifier: GPL-2.0 */ |
f3109a51 JK |
2 | /* |
3 | * Floating proportions with flexible aging period | |
4 | * | |
5 | * Copyright (C) 2011, SUSE, Jan Kara <jack@suse.cz> | |
6 | */ | |
7 | ||
8 | #ifndef _LINUX_FLEX_PROPORTIONS_H | |
9 | #define _LINUX_FLEX_PROPORTIONS_H | |
10 | ||
11 | #include <linux/percpu_counter.h> | |
12 | #include <linux/spinlock.h> | |
13 | #include <linux/seqlock.h> | |
20ae0079 | 14 | #include <linux/gfp.h> |
f3109a51 JK |
15 | |
16 | /* | |
17 | * When maximum proportion of some event type is specified, this is the | |
18 | * precision with which we allow limitting. Note that this creates an upper | |
19 | * bound on the number of events per period like | |
20 | * ULLONG_MAX >> FPROP_FRAC_SHIFT. | |
21 | */ | |
22 | #define FPROP_FRAC_SHIFT 10 | |
23 | #define FPROP_FRAC_BASE (1UL << FPROP_FRAC_SHIFT) | |
24 | ||
25 | /* | |
26 | * ---- Global proportion definitions ---- | |
27 | */ | |
28 | struct fprop_global { | |
29 | /* Number of events in the current period */ | |
30 | struct percpu_counter events; | |
31 | /* Current period */ | |
32 | unsigned int period; | |
33 | /* Synchronization with period transitions */ | |
34 | seqcount_t sequence; | |
35 | }; | |
36 | ||
20ae0079 | 37 | int fprop_global_init(struct fprop_global *p, gfp_t gfp); |
f3109a51 JK |
38 | void fprop_global_destroy(struct fprop_global *p); |
39 | bool fprop_new_period(struct fprop_global *p, int periods); | |
40 | ||
f3109a51 JK |
41 | /* |
42 | * ---- PERCPU ---- | |
43 | */ | |
44 | struct fprop_local_percpu { | |
45 | /* the local events counter */ | |
46 | struct percpu_counter events; | |
47 | /* Period in which we last updated events */ | |
48 | unsigned int period; | |
49 | raw_spinlock_t lock; /* Protect period and numerator */ | |
50 | }; | |
51 | ||
20ae0079 | 52 | int fprop_local_init_percpu(struct fprop_local_percpu *pl, gfp_t gfp); |
f3109a51 | 53 | void fprop_local_destroy_percpu(struct fprop_local_percpu *pl); |
be5f1797 MWO |
54 | void __fprop_add_percpu(struct fprop_global *p, struct fprop_local_percpu *pl, |
55 | long nr); | |
56 | void __fprop_add_percpu_max(struct fprop_global *p, | |
57 | struct fprop_local_percpu *pl, int max_frac, long nr); | |
f3109a51 JK |
58 | void fprop_fraction_percpu(struct fprop_global *p, |
59 | struct fprop_local_percpu *pl, unsigned long *numerator, | |
60 | unsigned long *denominator); | |
61 | ||
62 | static inline | |
63 | void fprop_inc_percpu(struct fprop_global *p, struct fprop_local_percpu *pl) | |
64 | { | |
65 | unsigned long flags; | |
66 | ||
67 | local_irq_save(flags); | |
be5f1797 | 68 | __fprop_add_percpu(p, pl, 1); |
f3109a51 JK |
69 | local_irq_restore(flags); |
70 | } | |
71 | ||
72 | #endif |