1 /** 2 * @file op_cpufreq.c 3 * get cpu frequency definition 4 * 5 * @remark Copyright 2003 OProfile authors 6 * @remark Read the file COPYING 7 * 8 * @author John Levon 9 * @author Philippe Elie 10 */ 11 12 #include <stdio.h> 13 #include <stdlib.h> 14 15 #include "op_fileio.h" 16 17 double op_cpu_frequency(void) 18 { 19 double fval = 0.0; 20 unsigned long uval; 21 char * line = NULL; 22 23 FILE * fp = op_try_open_file("/proc/cpuinfo", "r"); 24 if (!fp) 25 return 0.0; 26 27 while (1) { 28 line = op_get_line(fp); 29 30 if (!line) 31 break; 32 33 if (line[0] == '\0') { 34 free(line); 35 continue; 36 } 37 38 /* x86/parisc/ia64/x86_64 */ 39 if (sscanf(line, "cpu MHz : %lf", &fval) == 1) 40 break; 41 /* ppc/ppc64 */ 42 if (sscanf(line, "clock : %lfMHz", &fval) == 1) 43 break; 44 /* alpha */ 45 if (sscanf(line, "cycle frequency [Hz] : %lu", &uval) == 1) { 46 fval = uval / 1E6; 47 break; 48 } 49 /* sparc64 if CONFIG_SMP only */ 50 if (sscanf(line, "Cpu0ClkTck : %lx", &uval) == 1) { 51 fval = uval / 1E6; 52 break; 53 } 54 /* mips including loongson2 */ 55 if (sscanf(line, "BogoMIPS : %lu", &uval) == 1) { 56 fval = uval * 3 / 2; 57 break; 58 } 59 /* s390 doesn't provide cpu freq, checked up to 2.6-test4 */ 60 61 free(line); 62 } 63 64 if (line) 65 free(line); 66 op_close_file(fp); 67 68 return fval; 69 } 70
