sc/perf/README.md

Perf benchmark

Overview

• Using perf_event_open to get hardware and software counters.
• Only useful when you want to measure something inside the code really quick.
  Otherwise, use perf itself.
• Linux only.
• All predefined hardware and software counters are generated in the header
  file, you can uncomment counters as you wish.
• If some counters or combination of counters doesn't work or doesn't work as
  expected, please check out performance counter register allocation
  documentation for your CPU. CPUs have limited registers for performance
  counters and some counters can use specific registers only.
• Golang version : https://github.com/tezc/goperf

Usage

#include "sc_perf.h"  

int main(int argc, char *argv[])
{
    sc_perf_start();

    long_running_operation();

    sc_perf_end();
  
    return 0;
}

Output will be like

| Event                     | Value              | Measurement time  
---------------------------------------------------------------
| time (seconds)            | 0.66               | (100,00%)  
| cpu-clock                 | 654075766.00       | (100.00%)  
| task-clock                | 654077198.00       | (100.00%)  
| page-faults               | 3.00               | (100.00%)  
| context-switches          | 46.00              | (100.00%)  
| cpu-migrations            | 0.00               | (100.00%)  
| page-fault-minor          | 3.00               | (100.00%)  
| cpu-cycles                | 2656529748.00      | (100.00%)  
| instructions              | 7589235720.00      | (100.00%)  
| cache-misses              | 28715.00           | (100.00%)  
| L1D-read-miss             | 34124.00           | (100.00%)  
| L1I-read-miss             | 121958.00          | (100.00%) 

Pause example

#include "sc_perf.h"

int main(int argc, char *argv[])
{
    sc_perf_start();

    long_running_operation();

    //Will stop counters.
    sc_perf_pause();
    operation_you_dont_want_to_measure();

    //Start counters again.
    sc_perf_start();
    another_long_running_operation();

    sc_perf_end();
    
    sc_perf_start();
    some_other_long_running_operation();
    sc_perf_end();
  
    return 0;
}