CallNtPowerInformation and GetPwrCapabilities under Linux

Question

我的代码返回Windows下基于intel的系统上正在运行的cpu的信息。它是用CallNtPowerInformation和GetPwrCapabilities函数来做的。典型的返回信息有:maximum Mhz, current Mhz, maximum idle state, current idle state。

假设这是通过单个指令完成的，如cpuid。

我想有类似的代码在Linux下运行。有什么办法吗?

下面是我的Windows代码:

    /** cpustat.h -- Header for cpustat.cpp.                                                                                 
     * Copyright (c) 2004 Brad Fish ([e-mail]).                                                                   
     */
    #if !defined(MAIN_H)
    #define MAIN_H
    #include <windows.h>
    // missing Windows processor power information struct                                                                    
    typedef struct _PROCESSOR_POWER_INFORMATION {
      ULONG  Number;
      ULONG  MaxMhz;
      ULONG  CurrentMhz;
      ULONG  MhzLimit;
      ULONG  MaxIdleState;
      ULONG  CurrentIdleState;
    } PROCESSOR_POWER_INFORMATION , *PPROCESSOR_POWER_INFORMATION;
    int main (int argc, char *argv[]);
    #endif  // MAIN_H                                                                                                        
#include "cpustat.h"
#include <cstdio>
#include <vector>
#include <iostream>
extern "C" {
#include <powrprof.h>
}
int main (int argc, char *argv[])
{
    typedef std::vector<PROCESSOR_POWER_INFORMATION> PPIVector;
    SYSTEM_INFO sys_info;
    PPIVector ppis;
    SYSTEM_POWER_CAPABILITIES spc;
    // find out how many processors we have in the system                                                                    
    GetSystemInfo(&sys_info);
    ppis.resize(sys_info.dwNumberOfProcessors);
    // get CPU stats                                                                                                         
    if (CallNtPowerInformation(ProcessorInformation, NULL, 0, &ppis[0],
        sizeof(PROCESSOR_POWER_INFORMATION) * ppis.size()) != ERROR_SUCCESS)
    {
        perror("main: ");
        return -1;
    }
    // print out CPU stats                                                                                                   
    for (PPIVector::iterator it = ppis.begin(); it != ppis.end(); ++it)
    {
        std::cout << "stats for CPU " << it->Number << ':' << std::endl;
        std::cout << "  maximum MHz: " << it->MaxMhz << std::endl;
        std::cout << "  current MHz: " << it->CurrentMhz << std::endl;
        std::cout << "  MHz limit: " << it->MhzLimit << std::endl;
        std::cout << "  maximum idle state: " << it->MaxIdleState << std::endl;
        std::cout << "  current idle state: " << it->CurrentIdleState <<
            std::endl;
    }
    // get system power settings                                                                                             
    if (!GetPwrCapabilities(&spc))
    {
        perror("main: ");
        return -2;
    }
    // print power settings                                                                                                  
    std::cout << "system power capabilities:" << std::endl;
    std::cout << "  processor throttle: " <<
        (spc.ProcessorThrottle ? "enabled" : "disabled") << std::endl;
    std::cout << "  processor minimum throttle: " <<
        static_cast<int>(spc.ProcessorMinThrottle) << '%' << std::endl;
    std::cout << "  processor maximum throttle: " <<
        static_cast<int>(spc.ProcessorMaxThrottle) << '%' << std::endl;
}

Answer 1

您可以在/proc下的proc文件系统中查找一些信息，例如/proc/cpuinfo或/proc/acpi/processor/。

Answer 2

我们终于得到了一些这样做的代码。它使用cpuid指令:

#include <stdint.h>
#include <stdio.h>
#include <limits.h>
#define cpuid(id) __asm__( "cpuid" : "=a"(eax), "=b"(ebx), "=c"(ecx), "=d"(edx) : "a"(id), "b"(0), "c"(0), "d"(0))
#define b(val, base, end) ((val << (__WORDSIZE-end-1)) >> (__WORDSIZE-end+base-1))
int main(int argc, char **argv)
{
        unsigned long eax, ebx, ecx, edx;
        cpuid(0);
        printf("identification: "%.4s%.4s%.4s"n", (char *)&ebx, (char *)&edx, (char *)&ecx);
        printf("cpu information:n");
        cpuid(1);
        printf(" family %ld model %ld stepping %ld efamily %ld emodel %ldn",
                        b(eax, 8, 11), b(eax, 4, 7), b(eax, 0, 3), b(eax, 20, 27), b(eax, 16, 19));
        printf(" brand %ld cflush sz %ld*8 nproc %ld apicid %ldn",
                        b(ebx, 0, 7), b(ebx, 8, 15), b(ebx, 16, 23), b(ebx, 24, 31));
        cpuid(0x80000006);
        printf("L1 cache size (per core): %ld KBn", b(ecx, 16, 31));
        return(0);
}