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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This page was last edited on 21 Decemberat The second part of the output is the textual call graph, which shows for each function who called it parent and who it called child subroutines.

GNU gprof – Table of Contents

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. To use profiling, the program must be compiled and linked with the -pg profiling option:.

Sampling data is saved in ‘gmon. But tthe we’ve to profile the ghu using Gprof, I’ll have to use the -pg command line option provided by the gcc compiler. There’s no doubt that testing is an integral and one of the most important aspects of the software development process. The next step is to launch that executable.

Views Read Edit View history. If a value is n times the sampling period, the expected error in the value is the square root of n sampling periods. Needless to say, the best way to understand a tool like Gprof is through a practical example. Here’s how I launched the binary in my case: So, now use the Gprof tool in the following way:.


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. It used a hybrid of instrumentation and sampling [1] and was created as an extended version of the older “prof” tool. Unlike prof, gprof is capable of limited call graph collecting and printing. On this page What is Gprof?

First check whether or not the tool is already installed on your system. If broken down to the last bit, performance testing effectively tests how much time a particular piece of code – say a function – is consuming.

Webarchive template wayback links. The amount of error is usually more than one sampling period.

How to install and use profiling tool Gprof on Linux

A Selection, Kathryn S. The mcount function may not be thread-safe in some implementations, so multi-threaded application profiles can be incorrect typically it only profiles the main thread of application.

So, what exactly is Gprof? From Wikipedia, the free encyclopedia. Yes, my password is: Additional output breaking down the run-time further is also produced by gprof but not shown here. The source file ‘collatz. In case you already use Gprof, and want to share something related to the tool with everyone here, just drop in a comment below. Functions which consume a large fraction of the run-time can be identified easily from the output of gprof. This creates an instrumented executable which contains additional instructions that record the time spent in each function.

This feature is only available to subscribers. Armed with this information, now you’ll be in a better position to understand the data present in your profiling output file profile-data.


We will use gprof to examine the performance of a small numerical program which computes the lengths of sequences occurring in the unsolved Collatz conjecture in mathematics. 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. Here’s what the man gporf of Gprof says about information under these two sections:.

The resulting data is not exact, rather a statistical approximation. Do you already have an account? Before we move ahead, please note that all the examples and instructions mentioned in this tutorial have been tested on Ubuntu So, if through performance testing, we can enhance the performance of these functions in code, the overall performance of the software becomes better.

Gough, pgrof by Richard M. There is an external tool called gprof2dot capable of converting the call graph from gprof into graphical proviler. However, whatever we’ve covered here should be enough to get you started.

By using this site, you agree to the Terms gpdof Use and Privacy Policy. So, the command becomes:. It is this file which contains all the information that the Gprof tool requires to produce a human-readable profiling data.

Several gmon files can be combined with ‘gprof -s’ to accumulate data from several runs of a program. Efforts to speed up a program should concentrate first on those functions which dominate the total run-time.