allow seq_number == global_rank for TCP backend #407
Merged
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Summary:
All credit goes to original author XilunWu. I am just landing the code to unblock large training jobs.
D45740631 reduces gloo rendezvous cost for TCP backend by eliminating duplicate address publishing to TCPStore. Ben suggested "have seq_number == global_rank" to further get rid of
seq_number
exchange and Shawn reported why this didn't work. This diff serves a starting point for benchmarking the benefit of doing so (testbed record shows 2x speedup: 46 min ProcessGroupGloo init time on 8k ranks -> 20 min).The feature will be enabled via env variable (GLOO_ENABLE_RANK_AS_SEQUENCE_NUMBER) disabled by default that will be controlled by justKnobs.
Reviewed By: XilunWu
Differential Revision: D48130088