02 12 2020

Participants:

• Alex Margolin (Huawei)
• Akshay (NVIDIA)
• Artem Polyakov (Mellanox)
• Devendar Bureddy (Mellanox)
• Dmitry Gladkov (Mellanox)
• Evgeny Leksikov (Mellanox)
• Gil Bloch (Mellanox)
• James Dinan (NVIDIA)
• Ken Raffenetti (ANL)
• Manjunath Gorentla (Mellanox)
• Matt Baker (ORNL)
• Sergey Lebdev (Mellanox)
• Tony Curtis (SBU)
• Valentin Petrov (Mellanox)

Discussion

Hierarchical vs Reactive

• Alex discussed the slides in great detail (thanks!)
• Hierarchical and Reactive approaches have some similarities but different enough to achieve different performance optimizations.
• The collectives API should support interfaces for both hierarchical and reactive approaches to benefit various usage scenarios

Non-blocking vs Blocking

• Blocking interfaces have performance impact (provide better latency) for some cases - based on the experience from Mellanox and NVIDIA.
• Request for blocking barrier (from Akshay)
• Given issues surrounding the progress and non-blocking interfaces’ ability to support blocking interfaces, the inclination is to only support non-blocking interfaces for now and add blocking interfaces to the wish list.

Reproducibility

• Should this be a configuration option at the library level or team level? It seems like library level configuration should be enough.
• NVIDIA to provide more input on their requirements

Next Meeting: Feb 26th, 2020

• Potential agenda: Discussion of library initialization and local resource initialization.