1 /* SPDX-License-Identifier: GPL-2.0 */ 1 /* SPDX-License-Identifier: GPL-2.0 */
2 /* 2 /*
3 * Floating proportions with flexible aging pe 3 * Floating proportions with flexible aging period
4 * 4 *
5 * Copyright (C) 2011, SUSE, Jan Kara <jack@s 5 * Copyright (C) 2011, SUSE, Jan Kara <jack@suse.cz>
6 */ 6 */
7 7
8 #ifndef _LINUX_FLEX_PROPORTIONS_H 8 #ifndef _LINUX_FLEX_PROPORTIONS_H
9 #define _LINUX_FLEX_PROPORTIONS_H 9 #define _LINUX_FLEX_PROPORTIONS_H
10 10
11 #include <linux/percpu_counter.h> 11 #include <linux/percpu_counter.h>
12 #include <linux/spinlock.h> 12 #include <linux/spinlock.h>
13 #include <linux/seqlock.h> 13 #include <linux/seqlock.h>
14 #include <linux/gfp.h> 14 #include <linux/gfp.h>
15 15
16 /* 16 /*
17 * When maximum proportion of some event type 17 * When maximum proportion of some event type is specified, this is the
18 * precision with which we allow limitting. No 18 * precision with which we allow limitting. Note that this creates an upper
19 * bound on the number of events per period li 19 * bound on the number of events per period like
20 * ULLONG_MAX >> FPROP_FRAC_SHIFT. 20 * ULLONG_MAX >> FPROP_FRAC_SHIFT.
21 */ 21 */
22 #define FPROP_FRAC_SHIFT 10 22 #define FPROP_FRAC_SHIFT 10
23 #define FPROP_FRAC_BASE (1UL << FPROP_FRAC_SHI 23 #define FPROP_FRAC_BASE (1UL << FPROP_FRAC_SHIFT)
24 24
25 /* 25 /*
26 * ---- Global proportion definitions ---- 26 * ---- Global proportion definitions ----
27 */ 27 */
28 struct fprop_global { 28 struct fprop_global {
29 /* Number of events in the current per 29 /* Number of events in the current period */
30 struct percpu_counter events; 30 struct percpu_counter events;
31 /* Current period */ 31 /* Current period */
32 unsigned int period; 32 unsigned int period;
33 /* Synchronization with period transit 33 /* Synchronization with period transitions */
34 seqcount_t sequence; 34 seqcount_t sequence;
35 }; 35 };
36 36
37 int fprop_global_init(struct fprop_global *p, 37 int fprop_global_init(struct fprop_global *p, gfp_t gfp);
38 void fprop_global_destroy(struct fprop_global 38 void fprop_global_destroy(struct fprop_global *p);
39 bool fprop_new_period(struct fprop_global *p, 39 bool fprop_new_period(struct fprop_global *p, int periods);
40 40
41 /* 41 /*
42 * ---- PERCPU ---- 42 * ---- PERCPU ----
43 */ 43 */
44 struct fprop_local_percpu { 44 struct fprop_local_percpu {
45 /* the local events counter */ 45 /* the local events counter */
46 struct percpu_counter events; 46 struct percpu_counter events;
47 /* Period in which we last updated eve 47 /* Period in which we last updated events */
48 unsigned int period; 48 unsigned int period;
49 raw_spinlock_t lock; /* Protect per 49 raw_spinlock_t lock; /* Protect period and numerator */
50 }; 50 };
51 51
52 int fprop_local_init_percpu(struct fprop_local 52 int fprop_local_init_percpu(struct fprop_local_percpu *pl, gfp_t gfp);
53 void fprop_local_destroy_percpu(struct fprop_l 53 void fprop_local_destroy_percpu(struct fprop_local_percpu *pl);
54 void __fprop_add_percpu(struct fprop_global *p 54 void __fprop_add_percpu(struct fprop_global *p, struct fprop_local_percpu *pl,
55 long nr); 55 long nr);
56 void __fprop_add_percpu_max(struct fprop_globa 56 void __fprop_add_percpu_max(struct fprop_global *p,
57 struct fprop_local_percpu *pl, 57 struct fprop_local_percpu *pl, int max_frac, long nr);
58 void fprop_fraction_percpu(struct fprop_global 58 void fprop_fraction_percpu(struct fprop_global *p,
59 struct fprop_local_percpu *pl, unsigne 59 struct fprop_local_percpu *pl, unsigned long *numerator,
60 unsigned long *denominator); 60 unsigned long *denominator);
61 61
62 static inline 62 static inline
63 void fprop_inc_percpu(struct fprop_global *p, 63 void fprop_inc_percpu(struct fprop_global *p, struct fprop_local_percpu *pl)
64 { 64 {
65 unsigned long flags; 65 unsigned long flags;
66 66
67 local_irq_save(flags); 67 local_irq_save(flags);
68 __fprop_add_percpu(p, pl, 1); 68 __fprop_add_percpu(p, pl, 1);
69 local_irq_restore(flags); 69 local_irq_restore(flags);
70 } 70 }
71 71
72 #endif 72 #endif
73 73
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