GProf的使用

GProf的使用

• 1、安装gprof2dot.py

  下载地址 http://jrfonseca.googlecode.com/svn/trunk/gprof2dot/gprof2dot.py
  得到 gprof2dot-2021.2.21.tar.gz
  解压 tar -zvxf gprof2dot-2021.2.21.tar.gz
  

• 2、配置gprof2dot.py环境变量

  • 1、当前终端单次有效 执行命令 export PATH=$PATH:/home/gzrobot/gprof_dir/gprof2dot-2021.2.21

  • 2、当前用户永久有效

    vi ~/.profile

    通过 “:” 分割追加PATH

• 3、配置所有用户有效

  vi /etc/profile

  在最后加入 export PATH="=$PATH:/home/gzrobot/gprof_dir/gprof2dot-2021.2.21"

  再使用 source /etc/profile 使配置生效

#include <iostream>
#include <thread>
using namespace std;

int add(int a, int b)
{
        for(int i = 0; i < 10000; ++i)
        {
                ;
        }
        return a + b;
}

int sub(int a, int b)
{
        for(int i = 0; i < 5000; ++i)
        {;}
        return a - b;
}

int call()
{
        cout << add(1, 2) << endl;
        cout << sub(2, 4) << endl;
}


int main()
{
        for(int i = 0; i < 10000; ++i)
                call();
        return 0;
}

• 编译

  g++ -o test_gprof test_gprof.cpp -pg -std=c++11
  

• 运行程序，生成gmon.out

• 查看输出

  gprof ./prog gmon.out -b
  
   gzrobot@gzrobot:~/Gprof$ gprof ./test_gprof gmon.out -b
  Flat profile:
  
  Each sample counts as 0.01 seconds.
    %   cumulative   self              self     total
   time   seconds   seconds    calls  us/call  us/call  name
   57.13      0.30     0.30    10000    30.28    30.28  add(int, int)
   43.80      0.53     0.23    10000    23.21    23.21  sub(int, int)
    0.00      0.53     0.00    10000     0.00    53.50  call()
    0.00      0.53     0.00        1     0.00     0.00  _GLOBAL__sub_I__Z3addii
    0.00      0.53     0.00        1     0.00     0.00  __static_initialization_and_destruction_0(int, int)
  
                          Call graph
  
  
  
  granularity: each sample hit covers 2 byte(s) for 1.87% of 0.53 seconds
  
  index % time    self  children    called     name
                                                   <spontaneous>
  [1]    100.0    0.00    0.53                 main [1]
  
                  0.00    0.53   10000/10000       call() [2]
  -----------------------------------------------
  
                  0.00    0.53   10000/10000       main [1]
  
  [2]    100.0    0.00    0.53   10000         call() [2]
                  0.30    0.00   10000/10000       add(int, int) [3]
  
                  0.23    0.00   10000/10000       sub(int, int) [4]
  -----------------------------------------------
  
                  0.30    0.00   10000/10000       call() [2]
  
  [3]     56.6    0.30    0.00   10000         add(int, int) [3]
  -----------------------------------------------
  
                  0.23    0.00   10000/10000       call() [2]
  
  [4]     43.4    0.23    0.00   10000         sub(int, int) [4]
  -----------------------------------------------
  
                  0.00    0.00       1/1           __libc_csu_init [18]
  
  [11]     0.0    0.00    0.00       1         _GLOBAL__sub_I__Z3addii [11]
  
                  0.00    0.00       1/1           __static_initialization_and_destruction_0(int, int) [12]
  -----------------------------------------------
  
                  0.00    0.00       1/1           _GLOBAL__sub_I__Z3addii [11]
  
  [12]     0.0    0.00    0.00       1         __static_initialization_and_destruction_0(int, int) [12]
  -----------------------------------------------
  
  Index by function name
  
    [11] _GLOBAL__sub_I__Z3addii [4] sub(int, int)           [2] call()
     [3] add(int, int)          [12] __static_initialization_and_destruction_0(int, int)
                                                          , int)
  
  
  

• 生成图表

  gprof ./tmp | gprof2dot.py |dot -Tpng -o report.png