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/*
* (C) 2001 Dave Jones.
*
* Licensed under the terms of the GNU GPL License version 2.
*/
#include <stdio.h>
#include <sys/time.h>
#include <unistd.h>
#include <stdlib.h>
#include <string.h>
#include <signal.h>
#include "../x86info.h"
#include "bench.h"
static volatile int nosignal = 0;
static void sighandler(int sig __attribute__((unused)))
{
nosignal = 1;
}
void estimate_MHz(struct cpudata *cpu)
{
unsigned long long int cycles[2]; /* gotta be 64 bit */
unsigned int eax, ebx, ecx, edx;
unsigned long r;
if (cpu->number != 0) {
if (all_cpus == 0) {
cpu->MHz = firstcpu->MHz;
return;
}
}
/* Make sure we have a TSC (and hence RDTSC) */
cpuid(cpu->number, 1, &eax, &ebx, &ecx, &edx);
if ((edx & (1<<4)) == 0) {
printf("No TSC, MHz calculation cannot be performed.\n");
cpu->MHz = 0;
return;
}
if (signal(SIGALRM, sighandler) == SIG_ERR) {
printf("Some kind of signal failure.\n");
return;
}
cycles[0] = rdtsc();
alarm(1);
while (!nosignal)
r = r * rand();
nosignal = 0;
cycles[1] = rdtsc();
/* Check to see if rdtsc wrapped */
if (cycles[1] < cycles[0])
/* yes we did. */
cpu->MHz = ((-1ULL - cycles[0]) + cycles[1]) / 1000000;
else
cpu->MHz = (cycles[1] - cycles[0]) / 1000000;
if ((cpu->MHz % 50) > 15)
cpu->MHz = ((cpu->MHz / 50) * 50) + 50;
else
cpu->MHz = ((cpu->MHz / 50) * 50);
}
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