gprof Command in Linux
The gprof command in Linux is a powerful profiling tool that helps you analyze the performance of your C or C++ programs. It provides detailed information about the time spent in different functions and the call graph between them.
The gprof command in Linux is a profiling tool that provides information about the execution time of functions in a program. It can be used to identify performance bottlenecks and optimize code.
In this tutorial, we will show various examples of using the gprof command to profile applications in Linux.
Table of Contents
Here is a comprehensive guide to the options available with the gprof command −
- Understanding the gprof Command
- How to Use gprof Command?
- Options gprof Command
- Examples of gprof Command in Linux
Understanding the gprof Command
The gprof command in Linux is a powerful tool used for performance analysis of applications. It provides a detailed report of the time spent in each function of a program, helping developers identify areas where optimizations can be made to improve execution speed.
How to Use gprof Command?
gprof is a powerful profiling tool in Linux that helps you analyze the performance of your C or C++ programs. It provides detailed information about function call counts, execution times, and other relevant metrics, enabling you to identify bottlenecks and optimize your code for better efficiency.
Let install it −
sudo apt install binutils
Options gprof Command
Here are some of the most commonly used options / flags for the gprof command −
| Options | Descriptions |
|---|---|
| -b | Prints a summary of the flat profile. |
| -c | Prints the call graph profile. |
| -e | Excludes functions from the profile. |
| -l | Lists the functions in the profile. |
| -f | Prints the function index. |
| -z | Zeroes out the profile. |
| -s | Prints the symbol table. |
| -q | Prints the summary of the call graph profile. |
| -p | Prints the flat profile. |
| -B | Prints the backtrace profile. |
| -T | Prints the call graph profile in TeX format. |
| -X | Prints the call graph profile in YAML format. |
| -W | Prints the call graph profile in XML format. |
| -V | Prints the call graph profile in VCF format. |
| -U | Prints the call graph profile in Unicode format. |
| -M | Prints the call graph profile in Markdown format. |
| -D | Prints the detailed call graph profile. |
| -G | Prints the call graph profile in Graphviz format. |
| -F | Prints the function index for the call graph profile. |
| -E | Excludes functions from the call graph profile. |
| -R | Prints the call graph profile in SVG format. |
| -N | Prints the call graph profile in plain text format. |
| -Q | Prints the call graph profile in RST format. |
| -O | Prints the call graph profile in Org mode format. |
| -P | Prints the call graph profile in PostScript format. |
| -S | Prints the call graph profile in TXT format. |
| -H | Prints the call graph profile in HTML format. |
| -I | Prints the call graph profile in image format. |
| -J | Prints the call graph profile in JSON format. |
| -L | Prints the call graph profile in list format. |
| -K | Prints the call graph profile in LaTeX format. |
Examples of gprof Command in Linux
We have collected here a set of examples that highlight how you can use the gprof command in Linux:
- Basic Profiling
- Suppressing Descriptive Fields
- Visualizing Call Graphs
- Profiling Specific Functions
- Handling Large Programs
- Profiling Parallel Applications
- Print a Summary of the flat profile
Basic Profiling
The most straightforward use of gprof involves compiling your program with profiling enabled, running the program to generate profiling data, and then using gprof to analyze this data. Here's how you can do it −
Compile your program with the -pg flag to enable profiling −
gcc -pg program.c -o program
Run your program to generate the gmon.out file −
./program
Use gprof to analyze the profiling data and output the results to a file −
gprof program gmon.out > analysis.txt
Suppressing Descriptive Fields
If you want a cleaner output without the descriptive fields, you can use the -b option −
gprof -b program gmon.out > analysis.txt
Visualizing Call Graphs
For a visual representation of the call graph, you can use gprof to generate a call graph that illustrates the relationships between functions −
gprof program gmon.out | gprof2dot | dot -Tpng -o callgraph.png
(Note: gprof2dot and dot are separate tools that need to be installed for this visualization.)
Profiling Specific Functions
To focus on specific functions, you can use the -A and -Z options to include or exclude functions from the analysis −
gprof -Z function_name program gmon.out > analysis.txt
Handling Large Programs
For large programs with many functions, you can limit the output to the most time-consuming functions using the -m option −
gprof -m min-count program gmon.out > analysis.txt
Profiling Parallel Applications
When dealing with parallel applications, you can profile individual processes or all processes together −
gprof program gmon.out.18297 gmon.out.18300 gmon.out.9097 > analysis_all_processes.txt
Print a Summary of the Flat Profile
This command will print a summary of the flat profile for the program program.o using the profiling data in gmon.out −
gprof -b -p program.o gmon.out
Conclusion
The gprof command is a versatile tool that can greatly aid in the optimization of programs. By understanding and utilizing the different options and examples provided, developers can gain valuable insights into their applications' performance and make informed decisions on where to focus their optimization efforts.
By integrating gprof into the development workflow, programmers can ensure their applications are running efficiently and effectively, making the best use of system resources and providing an optimal experience for end-users. Whether you're working on a small project or a large-scale application, gprof is an essential tool in the Linux developer's toolkit.