Commit | Line | Data |
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f3109a51 JK |
1 | /* |
2 | * Floating proportions with flexible aging period | |
3 | * | |
4 | * Copyright (C) 2011, SUSE, Jan Kara <jack@suse.cz> | |
5 | */ | |
6 | ||
7 | #ifndef _LINUX_FLEX_PROPORTIONS_H | |
8 | #define _LINUX_FLEX_PROPORTIONS_H | |
9 | ||
10 | #include <linux/percpu_counter.h> | |
11 | #include <linux/spinlock.h> | |
12 | #include <linux/seqlock.h> | |
13 | ||
14 | /* | |
15 | * When maximum proportion of some event type is specified, this is the | |
16 | * precision with which we allow limitting. Note that this creates an upper | |
17 | * bound on the number of events per period like | |
18 | * ULLONG_MAX >> FPROP_FRAC_SHIFT. | |
19 | */ | |
20 | #define FPROP_FRAC_SHIFT 10 | |
21 | #define FPROP_FRAC_BASE (1UL << FPROP_FRAC_SHIFT) | |
22 | ||
23 | /* | |
24 | * ---- Global proportion definitions ---- | |
25 | */ | |
26 | struct fprop_global { | |
27 | /* Number of events in the current period */ | |
28 | struct percpu_counter events; | |
29 | /* Current period */ | |
30 | unsigned int period; | |
31 | /* Synchronization with period transitions */ | |
32 | seqcount_t sequence; | |
33 | }; | |
34 | ||
35 | int fprop_global_init(struct fprop_global *p); | |
36 | void fprop_global_destroy(struct fprop_global *p); | |
37 | bool fprop_new_period(struct fprop_global *p, int periods); | |
38 | ||
39 | /* | |
40 | * ---- SINGLE ---- | |
41 | */ | |
42 | struct fprop_local_single { | |
43 | /* the local events counter */ | |
44 | unsigned long events; | |
45 | /* Period in which we last updated events */ | |
46 | unsigned int period; | |
47 | raw_spinlock_t lock; /* Protect period and numerator */ | |
48 | }; | |
49 | ||
50 | #define INIT_FPROP_LOCAL_SINGLE(name) \ | |
51 | { .lock = __RAW_SPIN_LOCK_UNLOCKED(name.lock), \ | |
52 | } | |
53 | ||
54 | int fprop_local_init_single(struct fprop_local_single *pl); | |
55 | void fprop_local_destroy_single(struct fprop_local_single *pl); | |
56 | void __fprop_inc_single(struct fprop_global *p, struct fprop_local_single *pl); | |
57 | void fprop_fraction_single(struct fprop_global *p, | |
58 | struct fprop_local_single *pl, unsigned long *numerator, | |
59 | unsigned long *denominator); | |
60 | ||
61 | static inline | |
62 | void fprop_inc_single(struct fprop_global *p, struct fprop_local_single *pl) | |
63 | { | |
64 | unsigned long flags; | |
65 | ||
66 | local_irq_save(flags); | |
67 | __fprop_inc_single(p, pl); | |
68 | local_irq_restore(flags); | |
69 | } | |
70 | ||
71 | /* | |
72 | * ---- PERCPU ---- | |
73 | */ | |
74 | struct fprop_local_percpu { | |
75 | /* the local events counter */ | |
76 | struct percpu_counter events; | |
77 | /* Period in which we last updated events */ | |
78 | unsigned int period; | |
79 | raw_spinlock_t lock; /* Protect period and numerator */ | |
80 | }; | |
81 | ||
82 | int fprop_local_init_percpu(struct fprop_local_percpu *pl); | |
83 | void fprop_local_destroy_percpu(struct fprop_local_percpu *pl); | |
84 | void __fprop_inc_percpu(struct fprop_global *p, struct fprop_local_percpu *pl); | |
85 | void __fprop_inc_percpu_max(struct fprop_global *p, struct fprop_local_percpu *pl, | |
86 | int max_frac); | |
87 | void fprop_fraction_percpu(struct fprop_global *p, | |
88 | struct fprop_local_percpu *pl, unsigned long *numerator, | |
89 | unsigned long *denominator); | |
90 | ||
91 | static inline | |
92 | void fprop_inc_percpu(struct fprop_global *p, struct fprop_local_percpu *pl) | |
93 | { | |
94 | unsigned long flags; | |
95 | ||
96 | local_irq_save(flags); | |
97 | __fprop_inc_percpu(p, pl); | |
98 | local_irq_restore(flags); | |
99 | } | |
100 | ||
101 | #endif |