Automating the profling of C program using GPROF

问题

I am profiling a matrix multiplication C program using gprof. That C program has a general structure like this;

int main()

{

int n;

printf("enter size of square matrices");
scanf("%d", &n);

data(matM); //fill matrices with n x n random data 
data(matN); 

// this is unoptimized algo
matUnopt(int *matM, int *matN, int *MatOut, int size);


// this is optimized algo
matOpt(int *matM, int *matN, int *MatOut, int size);

 return(0);

}

Now at present how I am profiling is:

I run my executable mat, give size as 100 and then
$ gprof mat gmon.out > analysis1.txt

this generate analysis1.txt from where I manually note the timing for matOpt(); and matUnopt();

Then I again run the executable mat, and give n=150, and then

$  gprof mat gmon.out > analysis2.txt

this generate analysis2.txt from where I manually note the timing for matOpt(); and matUnopt();

and so on.

This is very time consuming and boring way. I want to automate this procedure. Some this like this:

int main()

{

int n;


for (n=50; n<50000; n++)

{      
  data(matM); //fill matrices with n x n random data 
  data(matN); 

// this is unoptimized algo
matUnopt(int *matM, int *matN, int *MatOut, int size);


 //gprof records the time of completion of matUnopt for the particular value of n, and 
 puts in a file 

 // this is optimized algo
 matOpt(int *matM, int *matN, int *MatOut, int size);


 //gprof records the time of completion of matOpt for the particular value of n, and   
puts in a file 


  }

  return(0);

  }

Once the application exits, I am expecting a file having a table like this:

run# (x 50)   profiling result (as usual we get from gprof)               

1             matUnopt  time .....
              matOpt    time .....  

2             matUnopt  time .....
              matOpt    time .....  

3             matUnopt  time .....
              matOpt    time .....  

4             matUnopt  time .....
              matOpt    time .....  


and so on.

Please note that 'profiling result' above is what we generally get from gprof. the important thing is I have an automated way to get the timing for the functions for multiple runs of the executable, that too with different input size.

This explanation is just a rough idea. I would be happy to get anything that approximates this. For example, the application might exit, and then restart of its own to get new profiling result. That is what I am actually doing. But I want to do this automatically.

How do I achieve this goal?

回答1:

Can you use a scripting language and give your size as an argument to the profiling binary?

For an example using arguments in c: passing arguments to main.

This bash script automatically runs your program with a matrix size from 50 till 50000. The tee command makes sure the output is printed and saved in the corresponding file: analysisxxx.txt

#!/bin/bash

for i in {50..50000}
do
    gprof mat gmon.out $i | tee analysis${i}.txt
done

I hope this helps you a little bit.

来源：https://stackoverflow.com/questions/20944097/automating-the-profling-of-c-program-using-gprof

标签

profiling

gprof