Delta Send-Recv: Run-time Support for Dynamic Pipelining of Coarse-grained Computation and Communication
Bin Bao, Chen Ding, Yaoqing Gao, Roch Archambaul · UR Research (University of Rochester) · 2010
The paper presents delta send-recv, an MPI extension for overlapping coarse-grained computation and communication. It provides an interface for marking the data computation and its communication. It automatically blocks computation and divides communication into increments. Delta sends and recvs are dynamically chained to effect sender-receiver pipelining, which is superior to pipelining only at the sender or the receiver side. The evaluation uses kernel tests to find the best increment size for different MPI implementations and types of machines and networks. It shows 2 to 3 times performance improvement for large-volume data reduce involving 16 or 32 processors. In addition, the new interface enables computation and communication pipelining in an interpreted programming language, Rmpi.