Date: 2026-07-16
The benchmark-only Xe2 compact scheduler is bitwise exact but does not clear
the predeclared 0.50 ms whole-verifier integration gate. It is rejected
before vLLM integration or another TP4 service load.
On B70 card 0, all 84 changed-input correctness cases passed. Coverage includes same/disjoint experts, cross-row overlap, within-row duplicates, all duplicates, twelve distinct local routes, and a valid all-remote EP rank. Both production routed MXFP4 shapes were checked:
The candidate was also checked against an independent fixed-M1 arithmetic oracle and direct slot-order gather, rather than trusting the formerly racy generic grouped-GEMM graph as the sole reference.
The generic persistent grouped-MXFP4 scheduler scans 40 local experts and uses
a global atomic work counter. The candidate launches directly over the twelve
M=2/top-k-6 route slots and N tiles. On device it derives each local expert’s
row count and remapped-row prefix from topk_ids plus expert_map; occurrence
0 and 8 own the two WG-M=8 tiles in the all-duplicate case. It preserves the
generic expert-grouped activation layout and cross-row weight reuse.
The implementation is preserved on XPU branch
codex/deepseek-v4-m2-compact-scheduler, commit ae1cbd472dced30741b5bdcd297fd5fd62a68f3d.
It remains benchmark-only: no fake/meta registration or production M=2 vLLM
dispatch was added.
The control was explicitly pinned to the promoted N64 policy. Timing alternated generic and candidate fixed-address XPU graph replays and used the minimum projected saving across every declared route pattern.
| Route pattern | Projected saved ms / 43 layers |
|---|---|
| same typical | 0.4691 |
| disjoint typical | 0.7405 |
| cross-row overlap | 0.4586 |
| within-row duplicate | 0.8297 |
| all duplicate | 0.5073 |
| twelve local routes | 0.4924 |
| all remote | 0.2618 |
The valid all-remote case is the fail-closed minimum. Running only favorable route patterns or averaging away this case would overstate real EP behavior. Because card 0 already failed the gate, cards 1-3 and service integration were not run.
Raw evidence is in
../../../data/deepseek-v4-reap-mxfp4-m2-compact-scheduler-20260716/card0.json.
The reusable probe is
../scripts/probe-mxfp4-m2-compact-scheduler.py.
Do not promote, submit to LocalMaxxing, or spend another service load on this scheduler alone. The candidate proves that removing only the persistent scheduler is still too small and route-dependent.
The next architectural screen should combine this scheduling idea with removal
of the M=2 remap and final permuted-gather boundaries while preserving grouped
expert reuse. The eager cycle profile attributes about 0.156 ms to remap and
0.151 ms to gather per verifier cycle; combining those boundaries with the
measured scheduler saving is the first remaining noncollective hypothesis with
a plausible >=0.50 ms ceiling. It still requires an exact real-shape
upper-bound gate before production integration.