kernel-ark/lib/pcounter.c
Arnaldo Carvalho de Melo de4d1db369 [LIB]: Introduce struct pcounter
This just generalises what was introduced by Eric Dumazet for the struct proto
inuse field in 286ab3d460:

    [NET]: Define infrastructure to keep 'inuse' changes in an efficent SMP/NUMA way.

Please look at the comment in there to see the rationale.

Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
2008-01-28 14:54:39 -08:00

27 lines
624 B
C

/*
* 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>
void pcounter_def_add(struct pcounter *self, int inc)
{
per_cpu_ptr(self->per_cpu_values, smp_processor_id())[0] += inc;
}
EXPORT_SYMBOL_GPL(pcounter_def_add);
int pcounter_def_getval(const struct pcounter *self)
{
int res = 0, cpu;
for_each_possible_cpu(cpu)
res += per_cpu_ptr(self->per_cpu_values, cpu)[0];
return res;
}
EXPORT_SYMBOL_GPL(pcounter_def_getval);