# Summary

OSPRI is a new one-sided runtime communication system for leadership-class supercomputers. It aims to provide more flexible semantics compared to existing one-sided communication systems (e.g. ​ARMCI) and target modern architectural trends by providing a thread-safe implementation.

Unlike its predecessor, ​A1, OSPRI will provide only functionality above and beyond what is available MPI, hence is designed to run side-by-side with MPI, not as an independent runtime.

The proper citation of OSPRI is:

OSPRI: J. R. Hammond, J. Dinan, P. Balaji, I. Kabadshow, S. Potluri, and V. Tipparaju, The 6th Conference on Partitioned Global Address Space Programming Models (PGAS). Santa Barbara, CA, October 2012. "OSPRI: An Optimized One-Sided Communication Runtime for Leadership-Class Machines."

The corresponding Bibtex is:

@inproceedings{Hammond:PGAS:2012:OSPRI,
   author = {Jeff R. Hammond and James Dinan and Pavan Balaji and Ivo Kabadshow and Sreeram Potluri and Vinod Tipparaju},
   title = {{OSPRI}: An Optimized One-Sided Communication Runtime for Leadership-Class Machines},
   booktitle = {The 6th Conference on Partitioned Global Address Space Programming Models ({PGAS})},
   month = oct,
   year = {2012},
   location = {Santa Barbara, CA, USA},
   url = {http://www.mcs.anl.gov/publications/paper_detail.php?id=1545},
}

Please see the [preprint](​http://www.mcs.anl.gov/publication/ospri-optimized-one-sided-communication-runtime-leadership-class-machines) for details.

# Goals of the project

• maximum communication performance
• scalability to millions of processes
• thread-safety
• support for hybrid systems (e.g. GPUs)
• modular design ala MPI
• software quality (readable, documented source code and robust build system)
• productive interaction with vendors

# Developers

Jeff Hammond, Sayan Ghosh, Sreeram Potluri, and Pavan Balaji have all contributed to this project.