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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I was much more concerned about why the profiling build of the app hung at gptof end, thereby preventing us from collecting the gmon,out files. Read more about Ramesh Natarajan and the blog. Note that I have used and will be using -b option so as to avoid extra information in analysis output.

I take it that no one knows why a -pg program just hangs at the end of execution?

By using this site, you agree to the Terms of Use and Privacy Policy. But because difference in loops is small, every time program executes we can get different sort results in flat profile. Responding to your revised third paragraph: Contact Us Email Me: Anything else that is different should be kept in mind too including — just saying and not suggesting this is it — system load. I could go into greater detail on any of these if necessary. Function call counts are also reported. The same goes the other way around too.


GPROF Tutorial – How to use Linux GNU GCC Profiling Tool

My focus is to write articles that will either teach you or help you resolve a problem. This file contains a couple of tables flat profile and call graph in addition to some other information.

Support Us Support this blog by purchasing one of my ebooks. Not to be confused with the perfect hash function generator gperf.

Hi Is it possible to set the gmon. In this first step, we need to make sure that the profiling is enabled when the compilation of the code is done. Views Read Edit View history. Cody February 28, Kiranjp September 3,1: 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. On a related note, you should also understand how to debug your C program using gdb.

Lets have a look at this text file:.

GPROF Tutorial – How to use Linux GNU GCC Profiling Tool

gni So we see that a flat profile containing information related to only function func1 is displayed. Bugs listed are irrelevant as again, just because something has a problem does not mean it is useless or never useful in any way shape or form.


Why would the profiling version hang up at the end of program execution like that?

The individual columns for the flat profile as well as call graph are very well explained in the output itself. My only comment here is that what we did get from the few profiling runs that ran to completion helped us identify exactly what the performance problems were.

GNU gprof – Table of Contents

It used a hybrid of instrumentation and sampling [1] and was created as an extended version of the older “prof” tool. In a large application like yours, 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.

Following test code will be used throughout the article:. This never happens when the non-profiling version bnu run. There is also an estimate of how much time gproff spent in the subroutines of each function.

I have followups enabled so if you respond maybe I can help more. Webarchive template wayback links.