Threads WG Meeting 10 30 2018

(Thanks Anshuman for the notes)

Agenda

• OpenSHMEM and MPI interoperability (Min)

Attendees

• Manjunath Gorentla (Mellanox)
• Naveen (Cray)
• Anshuman (NVIDIA)
• Min Si (ANL)
• Md Rahman (Intel)
• Dave (Intel)

Notes

• Interop slides presented by Min
• New API routines shmem_initialized and shmem_finalized
• Example shows when shmem_finalized is used : when MPI_Finalize causes SHMEM calls to be no longer available, shmem_finalized should return 1 in that case
• MPI_finalized, _initialized already defined in MPI spec
• Manju : shmem_initialized thread safety, multiple threads may call shmem_init
• rank/PE mapping : no mapping provided, user should query rank and PE separately for portable program
• Benefit of providing mapping is limited because needs all implementations to support which seems difficult
• Progress polling : required
• New APIs : initialized, finalized, query_interop (shmemx?)
• Manju : if property is implementation specific, then shmemx_ makes sense But if properties are unified across implementations, then shmem_
• Manju : concern over progress polling So can query_interop say no interop
• Manju’s suggestion : shmemx_ can be added in appendix