Scott Baden (Storm)

Greetings!

Scott is back and he brings some new ideas on one-sided communications with him. Come join us next week to learn more about it

Speaker

Scott Baden

When

Tuesday, May 9, 2023 at 4 pm.

Where

room George Boole 2 or online (Zoom link below)

Title

Collective Remote Procedure Calls

Abstract

RPC is a powerful construct for implementing irregular applications under PGAS and related models. We present Collective Remote Procedure Call, CRPC, a new primitive for SPMD programming that can be built atop RMA and thus provide native RPC's benefits in models lacking native support. CRPC amortizes startup overheads of data movement via aggregation, so the ideas are applicable to models that support RPC natively. We have implemented CRPC and evaluated it on up to 16K cores, using backends written in MPI and UPC++. We show that CRPC is performant while retaining the convenience of native RPC support. However, when combined with aggregation, UPC++'s RPC outperforms it at scale. Like conventional RPC, CRPC enhances programming productivity in irregular applications by enabling the programmer to express remote computation without the need to manage remote queues or buffers. However, native RPC++ Since CRPC can be implemented over conventional RMA it is thus portable over a wide range of communication libraries, e.g. OpenSHMEM, NVSHMEM.