获取cpu频率的代码

 // cpufreq库可在/usr/lib目录下找到
  
 			// 编译: g++ -g -o x x.cpp -lcpufreq
 
 			// 需要以root用户执行以下代码
 
 			//#include <cpufreq.h>
 
 			#include <stdio.h>
 
 			#include <sys/sysinfo.h> // get_nprocs
 
 
 
 			// 如果不存在/usr/include/cpufreq.h
 
 			#ifndef _CPUFREQ_H
 
 extern "C" int cpufreq_cpu_exists(unsigned int cpu);
 
 extern "C" unsigned long cpufreq_get_freq_kernel(unsigned int cpu);
 
 extern "C" unsigned long cpufreq_get_freq_hardware(unsigned int cpu);
 
 extern "C" int cpufreq_get_hardware_limits(unsigned int cpu, unsigned long *min, unsigned long *max);
 
 			#endif
 
 
 
 int main()
 
 			{
 
 			    // 取得cpu core的个数，proc是processor的意思
 
 int nprocs = get_nprocs();
 
 for (int i=0; i<nprocs; ++i)
 
 			    {
 
 if (0 == cpufreq_cpu_exists(i))
 
 			        { 
 
 			            unsigned long min_freq = 0;
 
 			            unsigned long max_freq = 0;
 
 			            cpufreq_get_hardware_limits(i, &min_freq, &max_freq);
 
 
 
 			            printf("cpu[%d]:\n", i); 
 
 			            printf("min_freq: %lu, max_freq: %lu\n", min_freq, max_freq);
 
 			            printf("kernel freq: %lu, hardware freq: %lu\n", cpufreq_get_freq_kernel(i), cpufreq_get_freq_hardware(i));
 
 			            printf("\n");
 
 			        } 
 
 			    } 
 
 
 
 			    return 0;
 
 			}