Section: New Results

Dynamic placement of Hybrid MPI +X coupled applications

We continued our collaboration with CERFACS in order to propose the Hippo software that addresses the issue of dynamic placement of computing kernels that feature each their own placement/mapping/binding policy of MPI processes and OpenMP threads. In such a case, enforcing a global placement policy for the whole application composed of several such kernels may be detrimental to the overall performance. Hippo (based on our Hsplit library and the hwloc software) is able to make the selection of the relevent resource on which some master MPI processes are going to execute and spawn OpenMP parallel sections while the remaining MPI processes are put in a “quiescence” state. Hippo is currently at the prototype stage and the interface and the set of provided functionnalities need some refinement, however, preliminary results are very encouraging, especially on climate modelling applications from Météo France.