Fix Python ep_test.py HT mode (under-sized recv buffers → ncclInvalidUsage) - #2252
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ybenvidia wants to merge 1 commit into
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Fix Python ep_test.py HT mode (under-sized recv buffers → ncclInvalidUsage)#2252ybenvidia wants to merge 1 commit into
ybenvidia wants to merge 1 commit into
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Signed-off-by: ybenabou <ybenabou@nvidia.com>
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In HT mode, ep_test.py set max_recv_tokens_per_rank = num_tokens * n_ranks (missing the * top_k factor) and sized the recv tensor as max_dispatch_tokens_per_rank * num_local_experts. Both under-size the HT receive buffer, so ncclEpDispatch fails with ncclInvalidUsage. ep_test.cu uses nRanks * num_tokens * top_k and num_recv_tokens = max_recv_tokens_per_rank. This aligns the Python reference with the C one; HT then passes 16/16 ranks (dispatch + combine verified). LL unchanged.