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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But since we’ve to profile the code using Gprof, I’ll have to use the -pg command line option provided by the gcc compiler. If a value is n times the sampling period, the expected error in the value is the square root of n sampling periods.

How to install and use profiling tool Gprof on Linux

Output is sorted by percentage, with hot spots at the top of the list. Gprof is a performance analysis tool for Unix applications. Your profiller or email address: Gough, foreword by Richard M.

So, what exactly is Gprof? At run-time, timing values are obtained by statistical sampling. This feature is only available to subscribers.

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.


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. Not to be confused with the perfect hash function generator gperf. Views Read Edit View history.


By using this site, you agree to the Terms of Use and Privacy Policy. So, we’ll start off with a C language program, which we’ll be profiling through Gprof. There’s no doubt that testing is an integral and one of the most important aspects of the software development process. Download and Install Gprof Gprof Usage. As is usually the case, a function or a group of functions may correspond to one of the many features of a software.

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

How to install and use profiling tool Gprof on Linux

The flat profile gives the total execution time spent in each function and its percentage of the total running time. Here’s what the man page of Gprof says about information under these two sections:. Consequently efforts to decrease the run-time of the program should concentrate on the former. The source file ‘collatz. The amount of error is usually more than one sampling period. Additional output breaking down the run-time further is also produced by gprof but not shown here.

Several gmon files can be combined with ‘gprof -s’ to accumulate data from several runs of a program. 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 profjler.

Now, moving on, the next step is to compile this code using gcc. Sampling data is saved in ‘gmon. A Selection, Kathryn S.

If broken down to the last bit, performance testing effectively tests how much time a particular piece of code – say a function – is consuming.

If the program consists of more than one source gprfo then the -pg option should be used when compiling each source file, and used again when linking the object files to create the final executable as shown above.


Forgetting to link with the option -pg is a common error, which prevents profiling from recording any useful information. First check whether or not the tool is already installed on your system. Function call counts are also reported. In case you want this information to be omitted from the output, proofiler can use the -b option provided by Gprof.

In case you already use Gprof, and want to share something related to the tool with everyone here, just drop in a comment below.

The other columns in the output provide information on the total number of function calls made, and the time spent in each function. No, create an account now. 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.

Cycles are discovered, and calls into a cycle are made to share the prpfiler of the cycle. So, the command becomes:.

From Wikipedia, the free encyclopedia. Do you already have an account? Reduce your monitoring cost, not your coverage. It used a hybrid of instrumentation and sampling [1] and was created as profler extended version of the older “prof” tool. Log in or Sign up.

From GProf to DTrace “2. However, whatever we’ve covered here should be enough to get you started. According to the tool’s gbu documentation, it gives users an execution profile of their C, Pascal, or Fortran77 programs.