/* $Id: self.c,v 1.32 2004/01/11 22:07:12 mikpe Exp $
*
* This test program illustrates how a process may use the
* Linux x86 Performance-Monitoring Counters interface to
* monitor its own execution.
*
* The library uses mmap() to map the kernel's accumulated counter
* state into the process' address space.
* When perfctr_read_ctrs() is called, it uses the RDPMC and RDTSC
* instructions to get the current register values, and combines
* these with (sum,start) values found in the mapped-in kernel state.
* The resulting counts are then delivered to the application.
*
* Copyright (C) 1999-2004 Mikael Pettersson
*/
#include <stdio.h>
#include <stdlib.h>
#include <errno.h>
#include <string.h>
#include "libperfctr.h"
#include "arch.h"
static struct vperfctr *self;
static struct perfctr_info info;
static struct vperfctr_control control;
void do_init(void)
{
struct perfctr_cpus_info *cpus_info;
self = vperfctr_open();
if( !self ) {
perror("vperfctr_open");
exit(1);
}
if( vperfctr_info(self, &info) < 0 ) {
perror("vperfctr_info");
exit(1);
}
cpus_info = vperfctr_cpus_info(self);
if( !cpus_info ) {
perror("vperfctr_cpus_info");
exit(1);
}
printf("\nPerfCtr Info:\n");
perfctr_info_print(&info);
perfctr_cpus_info_print(cpus_info);
free(cpus_info);
}
void do_read(struct perfctr_sum_ctrs *sum)
{
/*
* This is the preferred method for sampling all enabled counters.
* It doesn't return control data or current kernel-level state though.
* The control data can be retrieved using vperfctr_read_state().
*
* Alternatively you may call vperfctr_read_tsc() or vperfctr_read_pmc()
* to sample a single counter's value.
*/
vperfctr_read_ctrs(self, sum);
}
void print_control(const struct perfctr_cpu_control *control)
{
printf("\nControl used:\n");
perfctr_cpu_control_print(control);
}
void do_enable(void)
{
if( vperfctr_control(self, &control) < 0 ) {
perror("vperfctr_control");
exit(1);
}
}
void do_print(const struct perfctr_sum_ctrs *before,
const struct perfctr_sum_ctrs *after)
{
printf("\nFinal Sample:\n");
if( control.cpu_control.tsc_on )
printf("tsc\t\t\t%lld\n", after->tsc - before->tsc);
if( control.cpu_control.nractrs )
printf("pmc[0]\t\t\t%lld\n", after->pmc[0] - before->pmc[0]);
}
unsigned fac(unsigned n)
{
return (n < 2) ? 1 : n * fac(n-1);
}
void do_fac(unsigned n)
{
printf("\nfac(%u) == %u\n", n, fac(n));
}
int main(void)
{
struct perfctr_sum_ctrs before, after;
do_init();
memset(&control, 0, sizeof control);
do_setup(&info, &control.cpu_control);
print_control(&control.cpu_control);
do_enable();
do_read(&before);
do_fac(15);
do_read(&after);
do_print(&before, &after);
return 0;
}