Commit 095d9112 authored by Pavel Emelyanov's avatar Pavel Emelyanov Committed by David S. Miller
Browse files

[LIB]: Drop the pcounter itself.



The knock-out. The pcounter abstraction is not used any longer in the
kernel.

Not sure whether this should go via netdev tree, but as far as I
remember it was added via this one, and besides Eric thinks that
Andrew shouldn't mind this.
Signed-off-by: default avatarPavel Emelyanov <xemul@openvz.org>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent bdcde3d7
#ifndef __LINUX_PCOUNTER_H
#define __LINUX_PCOUNTER_H
/*
* Using a dynamic percpu 'int' variable has a cost :
* 1) Extra dereference
* Current per_cpu_ptr() implementation uses an array per 'percpu variable'.
* 2) memory cost of NR_CPUS*(32+sizeof(void *)) instead of num_possible_cpus()*4
*
* This pcounter implementation is an abstraction to be able to use
* either a static or a dynamic per cpu variable.
* One dynamic per cpu variable gets a fast & cheap implementation, we can
* change pcounter implementation too.
*/
struct pcounter {
#ifdef CONFIG_SMP
void (*add)(struct pcounter *self, int inc);
int (*getval)(const struct pcounter *self, int cpu);
int *per_cpu_values;
#else
int val;
#endif
};
#ifdef CONFIG_SMP
#include <linux/percpu.h>
#define DEFINE_PCOUNTER(NAME) \
static DEFINE_PER_CPU(int, NAME##_pcounter_values); \
static void NAME##_pcounter_add(struct pcounter *self, int val) \
{ \
__get_cpu_var(NAME##_pcounter_values) += val; \
} \
static int NAME##_pcounter_getval(const struct pcounter *self, int cpu) \
{ \
return per_cpu(NAME##_pcounter_values, cpu); \
} \
#define PCOUNTER_MEMBER_INITIALIZER(NAME, MEMBER) \
MEMBER = { \
.add = NAME##_pcounter_add, \
.getval = NAME##_pcounter_getval, \
}
static inline void pcounter_add(struct pcounter *self, int inc)
{
self->add(self, inc);
}
extern int pcounter_getval(const struct pcounter *self);
extern int pcounter_alloc(struct pcounter *self);
extern void pcounter_free(struct pcounter *self);
#else /* CONFIG_SMP */
static inline void pcounter_add(struct pcounter *self, int inc)
{
self->val += inc;
}
static inline int pcounter_getval(const struct pcounter *self)
{
return self->val;
}
#define DEFINE_PCOUNTER(NAME)
#define PCOUNTER_MEMBER_INITIALIZER(NAME, MEMBER)
#define pcounter_alloc(self) 0
#define pcounter_free(self)
#endif /* CONFIG_SMP */
#endif /* __LINUX_PCOUNTER_H */
......@@ -61,7 +61,6 @@ obj-$(CONFIG_TEXTSEARCH_KMP) += ts_kmp.o
obj-$(CONFIG_TEXTSEARCH_BM) += ts_bm.o
obj-$(CONFIG_TEXTSEARCH_FSM) += ts_fsm.o
obj-$(CONFIG_SMP) += percpu_counter.o
obj-$(CONFIG_SMP) += pcounter.o
obj-$(CONFIG_AUDIT_GENERIC) += audit.o
obj-$(CONFIG_SWIOTLB) += swiotlb.o
......
/*
* 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);
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