Embedded Linux Development Using Yocto Project Cookbook - Second Edition

How it works...

The perf tool provides statistics for both user and kernel events occurring in the system. It can function in two modes:

• Event counting (perf stat): This counts events in kernel context and prints statistics at the end. It has the least overhead.
• Event sampling (perf record): This writes the gathered data to a file at a given sampling period. The data can then be read as profiling (perf report) or trace data (perf script). Gathering data to a file can be resource intensive and the file can quickly grow in size.

By default, perf counts events for all the threads in the given command, including child processes, until the command finishes or is interrupted.

A generic way to run perf is as follows:

perf stat|record [-e <comma ...