Very confusing Virtual Pipeline Parallelism error message

[tjoymeed]

rank7: File "/usr/local/lib/python3.12/dist-packages/megatron/core/pipeline_parallel/schedules.py", line 809, in forward_backward_pipelining_with_interleaving
rank7: raise ValueError(msg)
rank7: ValueError: The number of contiguous micro-batches in a virtual pipeline stageshould range in [PP=6 , M=3]

How do I understand this error message?

Thanks!

[JRD971000]

@tjoymeed could you please explain more, and provide a simple reproducer (adding @yaoyu-33 and @akoumpa )