Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
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linux
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
12static 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
17static int pcounter_dyn_getval(const struct pcounter *self, int cpu)
18{
19 return per_cpu_ptr(self->per_cpu_values, cpu)[0];
20}
21
22int 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}
31EXPORT_SYMBOL_GPL(pcounter_getval);
32
33int 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}
46EXPORT_SYMBOL_GPL(pcounter_alloc);
47
48void 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}
57EXPORT_SYMBOL_GPL(pcounter_free);
58