Gprof is a performance analysis tool for Unix applications. It used a hybrid of instrumentation Another implementation was written as part of the GNU project for GNU GPROF output consists of two parts: the flat profile and the call graph. Gprof is a profiling program which collects and arranges statistics on your lly, it looks Write hate-mail to gnu (but don’t tell them I told you to). If you are a programmer, who writes code in C, Pascal, or Fortran77 programming language and uses Linux as the development platform, youll be glad to.

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Efforts to speed up a program should concentrate first on those functions which dominate the total run-time.

So, if through performance testing, we can enhance the performance of these functions in code, the overall performance of the software becomes better. Here’s what the man page of Gprof says about information under these two sections:.

How to install and use profiling tool Gprof on Linux

To do this, just run the following command in a profler. Gprof is a performance analysis tool for Unix applications. Cycles are discovered, and calls into a cycle are made to share the time of the cycle.

If you’re wondering about the source of above screenshots, let me tell you that all this information is there in the output file that contains the profiling information, including flat profile and call graph. Gnk feature is only available to subscribers. While running the instrumented executable, profiling data is silently written to a file ‘gmon.


Mutual recursion and non-trivial cycles are not resolvable by the gprof approach context-insensitive call graphbecause it only records arc traversal, not full call chains. First check whether or not the tool is already installed on your system. On this page What is Gprof?

Here’s the flat profile in my case:. This page was last edited on 21 Decemberat Here’s how I launched the binary in my case: Now, moving on, the next step is to compile this code using gcc. It can be analyzed with gprof by giving the name of the executable as an argument:.

Kessler, and Marshall K. No, create an account now. There’s no doubt that testing is an integral and one of the most important aspects of the software development process.

It used a hybrid of instrumentation and sampling [1] and was created as an extended version of the older “prof” tool. Your name or email address: To use profiling, the program must be compiled and linked with the -pg profiling option:.

And by testing, we don’t mean just testing the code for bugs – of course, bug detection is important as nobody would want their software to be buggy – performance of the code also equally matters these days. The resulting data is not exact, rather a statistical approximation. Gbu case you want this information to be omitted from the output, you can use the -b option provided by Gprof.

What Gprof basically does is, it calculates the amount of time spent in each routine or function. Gough, foreword by Richard M. Function call counts are also reported.

An Introduction to GCC – Using the profiler gprof

Functions which consume a large fraction of the gnk can be identified easily from the output of gprof. The GNU profiler gprof is a useful tool for measuring the performance of a program–it records the number of calls to each function and the amount of time spent there, on a per-function basis.


A call to the monitor function pofiler is inserted before each function call. If the program consists of more than one source file then the -pg option should be used when compiling each source profiiler, and used again when linking the object files to create the final executable as shown above. If all this sounds a bit confusing at this point especially the part in quotesdon’t worry, as we’ll make things clear through an example. Reduce your monitoring cost, not your coverage.

GNU gprof – Table of Contents

The next step is to launch that executable. Instrumentation code is automatically inserted into the program code during compilation for example, by using the ‘-pg’ option ths the gcc compilerto gather caller-function data. Sampling is done by probing the target program’s program counter at regular intervals using operating system interrupts programmed via profil 2 or setitimer 2 syscalls.

So, we’ll start off with a C language program, which we’ll be profiling through Gprof. The flat profile gives the gbu execution time spent in each function and its percentage of the total running time. Needless to say, the best way to understand a tool like Gprof is through a practical example.