TP / DP / PP Communication Overlap Skill

For stable background and recommendation level, see:

• @docs/training/communication-overlap.md

Enablement

Minimal Bridge override:

from megatron.bridge.training.comm_overlap import CommOverlapConfig

cfg.model.tensor_model_parallel_size = 4
cfg.model.sequence_parallel = True
cfg.model.pipeline_model_parallel_size = 4
cfg.model.virtual_pipeline_model_parallel_size = 2