add routing confidence metric#2545
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faresobeid wants to merge 1 commit into
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samsja
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May 18, 2026
| if values is None: | ||
| continue | ||
| value = values.mean() | ||
| reduce_op = dist.ReduceOp.MAX if name == "max_vio" else dist.ReduceOp.SUM |
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hmm what part? The if statement?
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yeah dont like it but also not sure how to do better
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Adds metric from stepfun3.5 flash paper to measure stability of MoE models routing for RL (and the need for router replay)
Note
Medium Risk
Adds new MoE routing-stat accumulation and changes router forward return signatures, which could affect training correctness/perf if any call sites assume the old outputs. Changes are limited to telemetry/stat buffers and logging paths, not core loss/optimizer logic.
Overview
Adds a new MoE routing confidence metric by accumulating the selected-expert probability mass in MoE routers (
TokenChoiceTopKRouterandNemotronHRouter) and tracking it via a newrouting_confidence_sumbuffer onMoE/LatentMoE.Extends
get_load_balance_stats()to return bothmax_vioandrouting_confidence(and reset both), and wires the new metric into RL and SFT training logs/monitoring with appropriate distributed reduction (MAX formax_vio, mean across ranks forrouting_confidence).Reviewed by Cursor Bugbot for commit 57679b1. Bugbot is set up for automated code reviews on this repo. Configure here.