1. A computer-implemented method to manage processes in a multicore processor using process affinity graphs, the method comprising: tracking interprocess message traffic for messages communicated between two or more related processes executing on separate processor cores of the multicore processor; determining affinity scores between each pair of the two or more related processes based at least in part on the tracked interprocess message traffic, wherein determining the affinity scores includes determining a total number of messages passed between the two or more related processes within a specified measurement period; assigning the two or more related processes to process affinity groups based at least in part on the affinity scores; and allocating the two or more related processes assigned to each process affinity group to one or more processor cores of the multicore processor based at least in part on the process affinity groups, wherein the allocating includes allocating the two or more related processes within a same process affinity group to physically adjacent separate processor cores within the multicore processor in response to the respective two or more related processes having higher affinity scores.