1. A method of mapping processes to processors in a parallel computing environment where a parallel application is run on a cluster of nodes, and a first node in the cluster of nodes has multiple processors sharing a common memory, the method comprising: using Message Passing Interface (MPI) to send a message from a first process of the parallel application uses to a second process of the parallel application; using, at a time of compiling the parallel application, a compiler to collect information about MPI point to point communication calls between the first process and the second process; and mapping, using the information about MPI point to point communication calls between the first process and the second process, the first process and the second process to different processors of the first node such that the message is delivered from the first process to the second process using the common memory of the first node.