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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Sameer March 11,1: If there are some static functions whose profiling information you do not require then this can be achieved using -a option:. Notify me of followup comments via e-mail.
That self time matters as opposed to inclusive time, which includes self time. I take it that no one knows why a -pg program just hangs at the end of execution? This never happens when the non-profiling version is run. The flat profile is mainly about self time, which in a large program is usually irrelevant because the real problems are mid-stack. Pgrof produces an analysis file which contains all the desired profiling information.
There were analogous utility in glibc called ‘sprof’ to profile dynamic libraries. While flat profile gives an ggprof of the timing information of the functions like time consumption for the execution of a particular function, how many times it was called etc. Kessler, and Marshall K. Now lets see the analysis output:.
It used a hybrid of instrumentation and sampling  and was created as an extended version of the older “prof” tool. If a value is n times the sampling period, the expected error in the value is the square root of n sampling periods.
Use this Contact Form to get in touch me with your comments, questions or suggestions about this site. The resulting data is not exact, rather a statistical ngu.
You can think the software is as fast as possible, when in fact it could be much faster. That samples need not be taken during IO or other blockage as opposed to sampling on wall-clock time. Function call counts are also reported. A Selection, Kathryn S. The man page, by the way, suggests this:.
Gprof – Wikipedia
This file gnh a couple of tables flat profile and call graph in addition to some other information. Also, if there is a requirement to print flat profile but excluding a particular function then this is also possible using -P flag by passing the function name to exclude along with it.
There is also an estimate of how much time was spent in the subroutines of each function. Also, I agree gporf recursion is not all that difficult.
In other words, in the hands of an experienced gpeof, it is a very valuable tool for exactly what you claim it isn’t good for. This helps make your program execution faster which is always desired. GPROF output consists of two parts: Mark Richter February 13, Thanks for this great article!
GPROF Tutorial – How to use Linux GNU GCC Profiling Tool
As you would have already seen that gprof produces output with lot of verbose yprof so in case this information is not required then this can be achieved using the -b flag. There is an external tool called gprof2dot capable of converting the call graph from gprof into graphical form. Mark Richter February 28,5: