unix% gprof program-name [ data-file ] [ > output-file ] Following the gprof command with “> output-file” causes the output of gprof to be saved to output-file so. Gprof is a profiling program which collects and arranges statistics on your lly, it looks into each of your functions and inserts code at the head. Gprof is a performance analysis tool used to profile applications to determine where time is spent . Searching the Web will turn up Gprof tutorials and more.

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If symspec is specified, gprof prints annotated source, but excludes matching symbols. Lets have a look at this text file:.

How to install and use profiling tool Gprof on Linux

Mark Richter February 13, Use this Contact Form to get in vprof me with your comments, questions or suggestions about this site. Different compilers have different mangling styles. If broken down to gpfof last bit, performance testing effectively tests how much time a particular piece of code – tutotial a function – is consuming. If you give the -z option, gprof will mention all functions in the flat profile, even those that were never called, and that had no time spent in them.

The -c option causes the call graph of the program to be augmented by a heuristic which examines the text space of the object file and identifies function calls in the binary machine code. This helps make your program execution faster which is always desired. That program counter sampling is useful as opposed to stack sampling.

Profiling with gcc and gprof

By default, only the lines at the beginning of a basic-block are annotated. I have been using gprof to isolate a performance issue in a large scale business application, but recent attempts to do this have stalled. Responding to your revised third paragraph: Not affiliated with Stack Overflow. To wrap any element that is callable std:: To gorof this, just run the following command in a terminal.


Normally, gprof prints annotated source files to standard-output. The number of histogram, call graph, and basic-block count records is displayed. The call graph shows, for each function, which functions called it, which other functions it called, and how many times.

gprof – Unix, Linux Command

The man page, by the way, suggests this: Sets width of output lines to width. The –file-ordering option causes gprof to print a suggested. Note that while execution if the program changes the current working directory using chdir then gmon. It is this file which contains all the information that the Gprof tool requires to produce a human-readable profiling data.

It produced the gmon. So, if through performance testing, we can enhance the performance of these functions in code, the overall performance of the software becomes better.

Rasna October 17, Also, I agree that recursion is not all that difficult. You can think the software is as fast as possible, when in fact it could be much faster.

I will be posting instruction guides, how-to, troubleshooting tips and tricks on Linux, database, hardware, security and web. Say for high performance applications.

Armed with this information, now you’ll be in a better position to understand the data present in your profiling output file profile-data. Do you already have an account? Next, these times are propagated along the edges of the call graph.

The -Q option causes gprof to suppress printing the call graph. The main thing I was getting at is gprof has its uses and to dismiss it entirely is not always helpful but then so would be dismissing your points — they are valid.


Parents or children identified via this heuristic are indicated in the call graph with call counts of 0. However, whatever we’ve covered here should be enough to get you started.

GPROF Tutorial – How to use Linux GNU GCC Profiling Tool

Andreas August 25,2: Selects the format of the profile data files. From the man page of gcc: The -d num option specifies debugging options. Build the application with settings for generating profiling information Generate profiling information by running the built application View the generated profiling information with gprof In order to build the application with settings for generating profiling information, we add the -pg flag.

So, for example, we could use. Use of the -a argument is highly recommended with this option. If you simply want to know which functions burn most of the cycles, it is stated concisely here.

Download and Install Gprof Gprof Usage. The format of the file is similar to the output of the program nm. 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.

The last step above produces an analysis file which is in human readable form. I take it that no one knows why a -pg program just hangs at the end of execution? Well your points are also valid. The -p option causes gprof to print a flat profile.