OProfile is a statistical profiler released under the GNU GPL license. The version included in the Yocto 1.7 release is a system-wide profiler, which uses the legacy profiling mode with a kernel module to sample hardware performance counters data and a user space daemon to write them to a file. More recent Yocto releases use newer versions that use the performance events subsystem, which we introduced in the Using the kernel's performance counters recipe, so they are able to profile processes and workloads as well.
The version included in Yocto 1.7 consists of a kernel module, a user space daemon to collect sample data, and several profiling tools to analyze captured data.
This recipe will focus on the OProfile version included in the 1.7 Yocto release.