Tuned: An open MPI collective communications component

Collective communications are invaluable to modern high performance applications, although most users of these communication patterns do riot always want to know their inner most working. The implementation of the collectives are often left, to the middle-ware developer such as those providing an MPI library. As many of these libraries are designed to be both generic and portable the MPI developers commonly offer internal timing options suitable only for knowledgeable users that allow some level of customization. The work presented in this paper aims riot only to provide a very efficient set of collective operations for rise with the Open MPI implementation but also to make the control and tuning of them straightforward and flexible.