the hardware-based performance monitoring interface for Linux Link to Linux and HP web site  
Libpfm4 documentation
This documentation pertains to libpfm4.X which is a helper library to help encode Performance Events to use with Operating system kernels performance monitoring interfaces. The current version provides support for the perf_events interface available in upstream Linux kernels since v2.6.31.
This version of libpfm is NOT for use with perfmon2.x.
Hardware PMU support for non X86-processors will be added gradually.
It is recommended you start by looking at the libpfm man page. The following man pages are available: