[Mpi3-rma] signaling / remote notification of one-sided call

[Vinod tipparaju]

Howard brought up this interesting topic.

Some one-sided model implementation have looked at remote notification of RMA operation primarily as a simple, low overhead, mechanism to inform the remote side of a one-sided operation. ARMCI has notify and wait calls per-process. GASNet has split-phase barrier with notify and wait collective calls. 

However, I am not very convinced that this is as important for MPI RMA. This can be achieved with a send-recv call after a one-sided call. 

Lets start a small discussion about this. 

signaling/notification of a remote call

eg: Sender - RMA_Xfer_notify or RMA_Xfer followed by Notify(context)  Receiver: Wait(context)

Merits: performance? ease of programming? 

Demerits: duplicate functionality? many alternatives to do the same thing? not a noticeable performance gain?

Thanks,
Vinod.