likwid


Lightweight performance tools

NEWS (last update 15.6.2015):

Due to the end of the Google Code service we moved LIKWID to github.
You can find us here:

https://github.com/rrze-likwid/likwid'>https://github.com/rrze-likwid/likwid

This site will not be maintained anymore. The mailing lists will stay at Google groups for now.


Likwid stands for Like I knew what I am doing. This project contributes easy to use command line tools for Linux to support programmers in developing high performance multi threaded programs.

It contains the following tools:

  • likwid-topology: Show the thread and cache topology
  • likwid-perfctr: Measure hardware performance counters on Intel and AMD processors
  • likwid-features: Show and Toggle hardware prefetch control bits on Intel Core 2 processors
  • likwid-pin: Pin your threaded application without touching your code (supports pthreads, Intel OpenMP and gcc OpenMP)
  • likwid-bench: Benchmarking framework allowing rapid prototyping of threaded assembly kernels
  • likwid-mpirun: Script enabling simple and flexible pinning of MPI and MPI/threaded hybrid applications
  • likwid-perfscope: Frontend for likwid-perfctr timeline mode. Allows live plotting of performance metrics.
  • likwid-powermeter: Tool for accessing RAPL counters and query Turbo mode steps on Intel processor.
  • likwid-memsweeper: Tool to cleanup ccNUMA memory domains and force eviction of dirty cachelines from caches.
  • likwid-setFrequencies: Tool to set specific processor frequencies.

Likwid stands out because:

  • No kernel patching, any vanilla linux 2.6 or newer kernel works
  • Transparent, always clear which events are chosen, event tags have the same naming as in documentation
  • Lightweight, LIKWID tries to add no overhead and keeps out of your way.
  • Easy to use, simple to build, no need to touch your code, configurable from outside. Clear CLI interface.
  • Multiplatform, likwid supports Intel and AMD processors
  • Up to date, likwid tries to fully support new processors as soon as possible
  • Extensible, you can add functionality by means of simple text files

If you encounter problems feel free to ask questions in the http://groups.google.com/group/likwid-users'>User Mailing List.