A portable collective communication library using communication schedules.
Tim Rühl, Henri E. Bal · 1997
We describe a flexible and efficient implementation of a portable collective communication library based on communication schedules. With communication schedules the communication pattern of an operation is expressed before it is actually executed. We provide a simple set of functions to create such a communication schedule and to check whether the communication pattern is correct. Analyzing this communication schedule provides information that can be used at run-time to reduce the number of acknowledgment messages and to eliminate the overhead of context switching during data forwarding. 1. Introduction Efficient communication is crucial for the performance of most parallel applications. Unfortunately, a highly tuned parallel programming system for a specific architecture may be hard to port to other architectures. We have implemented a virtual machine called Panda [17] that achieves both portability and efficiency. Panda provides threads and communication to higher software layers ...