Notified Access: Extending Remote Memory Access Programming Models for Producer-Consumer Synchronization

Roberto Belli, Torsten Hoefler
2015 2015 IEEE International Parallel and Distributed Processing Symposium  
Remote Memory Access (RMA) programming enables direct access to low-level hardware features to achieve high performance for distributed-memory programs. However, the design of RMA programming schemes focuses on the memory access and less on process synchronization. For example, in contemporary RMA programming systems, the widely used producer-consumer pattern can only be implemented inefficiently, incurring the overhead of an additional roundtrip message. We propose Notified Access, a scheme
more » ... re the target process of an access can receive a completion notification. This scheme enables direct and efficient synchronization with a minimum number of messages. We implement our scheme in an open source MPI-3 RMA library and demonstrate lower overheads (two cache misses) than other point-to-point synchronization mechanisms. We also evaluate our implementation on three real-world benchmarks: a stencil computation, a tree computation, and a Cholesky factorization implemented with tasks. Our scheme always performs better than traditional message passing and other existing RMA synchronization schemes, providing up to 50% speedup on small messages. Our analysis shows that Notified Access is a valuable primitive for any RMA system. Furthermore, we provide guidance for the design of low-level network interfaces to support Notified Access efficiently.
doi:10.1109/ipdps.2015.30 dblp:conf/ipps/BelliH15 fatcat:vihdr3456zd5popdbgdd5h7hdi