1 #ifndef __LINUX_PCOUNTER_H
2 #define __LINUX_PCOUNTER_H
6 void (*add
)(struct pcounter
*self
, int inc
);
7 int (*getval
)(const struct pcounter
*self
);
15 * Special macros to let pcounters use a fast version of {getvalue|add}
16 * using a static percpu variable per pcounter instead of an allocated one,
17 * saving one dereference.
18 * This might be changed if/when dynamic percpu vars become fast.
21 #include <linux/cpumask.h>
22 #include <linux/percpu.h>
24 #define DEFINE_PCOUNTER(NAME) \
25 static DEFINE_PER_CPU(int, NAME##_pcounter_values); \
26 static void NAME##_pcounter_add(struct pcounter *self, int inc) \
28 __get_cpu_var(NAME##_pcounter_values) += inc; \
31 static int NAME##_pcounter_getval(const struct pcounter *self) \
35 for_each_possible_cpu(cpu) \
36 res += per_cpu(NAME##_pcounter_values, cpu); \
40 #define PCOUNTER_MEMBER_INITIALIZER(NAME, MEMBER) \
42 .add = NAME##_pcounter_add, \
43 .getval = NAME##_pcounter_getval, \
46 extern void pcounter_def_add(struct pcounter
*self
, int inc
);
47 extern int pcounter_def_getval(const struct pcounter
*self
);
49 static inline int pcounter_alloc(struct pcounter
*self
)
52 if (self
->add
== NULL
) {
53 self
->per_cpu_values
= alloc_percpu(int);
54 if (self
->per_cpu_values
!= NULL
) {
55 self
->add
= pcounter_def_add
;
56 self
->getval
= pcounter_def_getval
;
63 static inline void pcounter_free(struct pcounter
*self
)
65 if (self
->per_cpu_values
!= NULL
) {
66 free_percpu(self
->per_cpu_values
);
67 self
->per_cpu_values
= NULL
;
73 static inline void pcounter_add(struct pcounter
*self
, int inc
)
78 static inline int pcounter_getval(const struct pcounter
*self
)
80 return self
->getval(self
);
83 #else /* CONFIG_SMP */
85 static inline void pcounter_add(struct pcounter
*self
, int inc
)
90 static inline int pcounter_getval(const struct pcounter
*self
)
95 #define DEFINE_PCOUNTER(NAME)
96 #define PCOUNTER_MEMBER_INITIALIZER(NAME, MEMBER)
97 #define pcounter_alloc(self) 0
98 #define pcounter_free(self)
100 #endif /* CONFIG_SMP */
102 #endif /* __LINUX_PCOUNTER_H */