author	 = {Jannek Squar},
	title	 = {{MPI-3 algorithms for 3D radiative transfer on Intel Xeon Phi coprocessors}},
	advisors	 = {Peter Hauschildt and Michael Kuhn},
	year	 = {2016},
	month	 = {10},
	school	 = {Universität Hamburg},
	type	 = {Master's Thesis},
	abstract	 = {One-sided communication has been added to the MPI standard with MPI-2 in 1997 and has been greatly extended with the introduction of MPI-3 in 2012. Even though one-sided communication offers many use cases, from which an application could benefit, it has only sporadically been used for HPC so far. The objective of this thesis is to examine its potential use for replacing a OpenMP section with equivalent code, which only makes use of MPI. This is done based on an already existing application, named PHOENIX. This application is currently developed at the observatory of Hamburg and has been designed to be executed on HPC systems. Its purpose is, among other things, to numerically solve the equations of 3D radiative transfer for stellar objects. For utilising HPC hardware at its full capacity PHOENIX makes use of MPI and OpenMP. In the course of this thesis a test application has been constructed, which mimics the OpenMP sections and allows to benchmark diverse combinations of MPI one-sided communication operations. The benchmarks are performed on a Intel Xeon Phi Knights Corner and on a Intel Xeon Phi Knights Landing to estimate if a certain approach is suitable for HPC hardware in general. In the end each approach is discussed and assessed which kind of communication pattern might benefit most of MPI one-sided communication.},