slub: Deal with config variable dependencies
[linux-2.6.git] / lib / pcounter.c
1 /*
2  * Define default pcounter functions
3  * Note that often used pcounters use dedicated functions to get a speed increase.
4  * (see DEFINE_PCOUNTER/REF_PCOUNTER_MEMBER)
5  */
6
7 #include <linux/module.h>
8 #include <linux/pcounter.h>
9 #include <linux/smp.h>
10 #include <linux/cpumask.h>
11
12 static void pcounter_dyn_add(struct pcounter *self, int inc)
13 {
14         per_cpu_ptr(self->per_cpu_values, smp_processor_id())[0] += inc;
15 }
16
17 static int pcounter_dyn_getval(const struct pcounter *self, int cpu)
18 {
19         return per_cpu_ptr(self->per_cpu_values, cpu)[0];
20 }
21
22 int pcounter_getval(const struct pcounter *self)
23 {
24         int res = 0, cpu;
25
26         for_each_possible_cpu(cpu)
27                 res += self->getval(self, cpu);
28
29         return res;
30 }
31 EXPORT_SYMBOL_GPL(pcounter_getval);
32
33 int pcounter_alloc(struct pcounter *self)
34 {
35         int rc = 0;
36         if (self->add == NULL) {
37                 self->per_cpu_values = alloc_percpu(int);
38                 if (self->per_cpu_values != NULL) {
39                         self->add    = pcounter_dyn_add;
40                         self->getval = pcounter_dyn_getval;
41                 } else
42                         rc = 1;
43         }
44         return rc;
45 }
46 EXPORT_SYMBOL_GPL(pcounter_alloc);
47
48 void pcounter_free(struct pcounter *self)
49 {
50         if (self->per_cpu_values != NULL) {
51                 free_percpu(self->per_cpu_values);
52                 self->per_cpu_values = NULL;
53                 self->getval = NULL;
54                 self->add = NULL;
55         }
56 }
57 EXPORT_SYMBOL_GPL(pcounter_free);
58