In this article, we will explore the GNU profiling tool ‘gprof’. In this step, the gprof tool is run with the executable name and the above. What is gprof? Gprof is a profiling program which collects and arranges statistics on your programs. Write hate-mail to gnu (but don’t tell them I told you to). Table of Contents. 1. Introduction to Profiling · 2. Compiling a Program for Profiling · 3. Executing the Program · 4. gprof Command Summary · Output Options.

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Antoha Bikineev October 30, Lets have a look at this text file:.

Andreas August 25,2: It produced the gmon. Cody February 27,7: Just mentioning that because I see that complaint a lot.

GPROF Tutorial – How to use Linux GNU GCC Profiling Tool

Some of them are discussed below:. From Wikipedia, the free encyclopedia.

Unlike prof, gprof is capable of limited call graph collecting and printing. Indeed, it can always get faster and that is the con and pro of higher level languages; on the one hand, you can get more done sooner but on the other hand the executable will be larger and the executable will not be as efficient or as fast. I think point 10 is exactly what I was getting at: So we see that a flat profile containing information related to only function func1 is displayed.

Table of Contents

As you would have already seen that gprof produces output with lot of verbose information so in case this information is not required then this can be achieved using the -b flag. You must use this option when compiling the source files you want data about, and you must also use it when linking.


In some versions, such as BSD, profiling of shared libraries can be limited because of restrictions of the profil function, which may be implemented as library function or as system call. In flat profile we expect that func1 works longer than func2.

Mike Dunlavey February 28,8: Hi Is it possible to set the gmon. Anonymous July 30,6: Note that while execution if the program changes the current working directory using chdir then gmon.

Gprof – Wikipedia

By using this site, you agree to the Terms of Use and Privacy Policy. The man page, by the way, suggests this: In very large projects, profiling can save your day by not only determining the parts in your program which are slower in execution than expected but also can help you find many other statistics through which many potential bugs can be spotted and sorted out. The same goes the other way around too.

That measuring time of functions is good enough gpof opposed to lines of code or even instructions. That the call graph is important as opposed to the information in stack samples. A call to the monitor function ‘mcount’ is inserted before each function call.

This produces an analysis file which contains all the desired profiling information. Sameer March 11,1: Hi Mike, Well your points are also valid. Retrieved from ” https: Lets try and understand the three steps listed above through a practical example.


All rights reserved Terms of Service. That samples have to gorof taken at high frequency they do not. That program counter sampling is useful as opposed to stack sampling.

Also, your program needs to have sufficient permissions for gmon. Output is sorted by percentage, with hot spots at the top of the list.

You can also simply drop me a line to say hello!. Alex February 21, Read more about Ramesh Natarajan and hprof blog. Why would the profiling version hang up at the end of program execution like that?

GPROF Tutorial – How to use Linux GNU GCC Profiling Tool

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. I will be posting instruction guides, how-to, troubleshooting tips and tricks on Linux, database, hardware, security and web. You can think the software is as fast as possible, when in fact it could be much faster. Also, if it is desired to suppress a specific function from call graph then this can be achieved by passing the desired function name along with the -Q option to the gprof tool.

Well, I ran the proram again, and this time it produced the gmon. The reason ctrl-c prevents it from producing a gmon. Function call counts are also reported.