Write 2-sided MPI version of ICAR for benchmarking

[bcfriesen]

One appealing feature of coarrays is the one-sided nature of the communication among images, allowing overlap of communication and computation. OpenCoarrays exploits this by using RMA functions and shared memory windows in MPI 3.

It would be interesting to measure what benefit ICAR sees in using one-sided communication via coarrays, over the traditional two-sided MPI communication which has been the standard programming model for bulk-synchronous parallel applications for many years. We can measure this by writing an analogous two-sided MPI version of ICAR and comparing the performance with the coarray version.

[rouson]

@afanfa

@gutmann and I think this issue offers great bang for the buck in terms of preparing for an SC18 submission.

[rouson]

@bcfriesen Cranfield University Ph.D. student Soren Rasmussen (@scrasmussen) has agreed to work this issue starting this week. He just arrived for a one-week visit at the worldwide headquarters of Sourcery Institute. :) If you've already done anything this, please let us know. Otherwise, he'll create a new branch and start working toward having this written up in time for the July 31 PAW-ATM workshop deadline.

[bcfriesen]

Thanks for the update, @rouson. I haven't progressed on this at all. Glad to hear that Soren is working on it now.