pcounter.c
1.24 KB
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/*
* Define default pcounter functions
* Note that often used pcounters use dedicated functions to get a speed increase.
* (see DEFINE_PCOUNTER/REF_PCOUNTER_MEMBER)
*/
#include <linux/module.h>
#include <linux/pcounter.h>
#include <linux/smp.h>
#include <linux/cpumask.h>
static void pcounter_dyn_add(struct pcounter *self, int inc)
{
per_cpu_ptr(self->per_cpu_values, smp_processor_id())[0] += inc;
}
static int pcounter_dyn_getval(const struct pcounter *self, int cpu)
{
return per_cpu_ptr(self->per_cpu_values, cpu)[0];
}
int pcounter_getval(const struct pcounter *self)
{
int res = 0, cpu;
for_each_possible_cpu(cpu)
res += self->getval(self, cpu);
return res;
}
EXPORT_SYMBOL_GPL(pcounter_getval);
int pcounter_alloc(struct pcounter *self)
{
int rc = 0;
if (self->add == NULL) {
self->per_cpu_values = alloc_percpu(int);
if (self->per_cpu_values != NULL) {
self->add = pcounter_dyn_add;
self->getval = pcounter_dyn_getval;
} else
rc = 1;
}
return rc;
}
EXPORT_SYMBOL_GPL(pcounter_alloc);
void pcounter_free(struct pcounter *self)
{
if (self->per_cpu_values != NULL) {
free_percpu(self->per_cpu_values);
self->per_cpu_values = NULL;
self->getval = NULL;
self->add = NULL;
}
}
EXPORT_SYMBOL_GPL(pcounter_free);