LIKWID: A lightweight performance-oriented tool suite for x86 multicore environments

Exploiting the performance of today's processors requires, apart from an intimate knowledge of the microarchitecture, taking into account the influence of an ever-growing complexity in thread and cache topology. LIKWID is a collection of small command line applications that support inexperienced as well as seasoned programmers in developing and running software in an efficient way. The development of LIKWID is targeted on providing access to performance-oriented tooling in a transparent and easy manner. We present the four tools that comprise LIKWID and show the influence of thread pinning on performance using the well-known OpenMP STREAM triad benchmark. On the example of a stencil code specifically optimized to utilize cache topology we demonstrate the usage of likwid-pin and likwid-perfCtr.