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[SM120] DeepGEMM MoE + FlashInfer attention for DSv4#4

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xutizhou merged 4 commits into
xutizhou:deepseek-base-optimizationfrom
AliceChenyy:sm120-deepgemm-opt-merge
Jun 12, 2026
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[SM120] DeepGEMM MoE + FlashInfer attention for DSv4#4
xutizhou merged 4 commits into
xutizhou:deepseek-base-optimizationfrom
AliceChenyy:sm120-deepgemm-opt-merge

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Summary

  • DeepGEMM MoE integration: Replace Marlin with DeepGEMM grouped FP8xFP4 GEMM on SM120, with UE8M0 power-of-2 FP8 quantization kernel. TTFT 130ms (3x faster than Marlin 400ms).
  • Fused swiglu_limit: Clamp fused into SiLU+Mul+Quant Triton kernel, eliminating ~21 elementwise kernels/step. Decode ITL 41.5ms → 33.0ms (-20%).
  • FlashInfer sparse MLA decode: CUTLASS SM120 sparse_mla_sm120 with fused page-split kernel (pbs=256 → pbs=64). Decode ITL 95ms → 33ms with FlashInfer.

Cherry-picked commits from AliceChenyy/sglang:sm120-deepgemm-opt

  1. c409765 — [SM120] DeepGEMM MoE integration
  2. 60d81d2 — [SM120] Optimize DeepGEMM decode: fuse swiglu_limit clamp
  3. 14a6b91 — [SM120] Fuse swiglu_limit clamp into SiLU+Mul+Quant Triton kernel
  4. 9f3b532 — [SM120] Add FlashInfer attention files

Dependencies

  • DeepGEMM SM120 fork: leavelet/DeepGEMM@sm120
  • FlashInfer SM120 sparse MLA: lucifer1004/flashinfer@sparse-mla-sm120

Files changed (8 files, +360 -37)

  • deepseek_v4_backend.py — dynamic swa_page_size, relaxed assertion
  • flash_mla_sm120.py — FlashInfer dispatch + page-split Triton kernel
  • configurer.py — SM120 DeepGEMM feature detection
  • kernels.py — FP8 pow2 quant kernel + fused swiglu_limit in silu_mul_quant
  • deep_gemm.py — DeepGEMM MoE runner, Triton fallback path, in-place swiglu
  • fp8.py.contiguous() fix for scale layout transform
  • fp8_utils.py — Skip JIT DeepGEMM linear on SM120
  • server_args.py — Default moe_runner_backend=deep_gemm on SM120

Test plan

  • Correctness: GSM8K 10q on RTX PRO 6000 TP=4
  • Perf: decode ITL + TTFT benchmark vs Marlin baseline
  • Verify uint8 E8M0 scale compatibility with DeepGEMM path

AliceChenyy and others added 4 commits June 11, 2026 09:02
…pGEMM@sm120)

Enable DeepGEMM grouped FP8×FP4 GEMM for MoE on SM120 (RTX 6000D/PRO 6000).
Requires leavelet/DeepGEMM@sm120 branch (deepseek-ai/DeepGEMM#324, not yet merged).

Changes:
- configurer.py: Allow SM120 only when SM120-compatible DeepGEMM is installed
  (checks for m_grouped_fp8_fp4_gemm_nt_contiguous availability)
- server_args.py: Auto-select deep_gemm MoE backend on SM120
- kernels.py: Add UE8M0 (power-of-2) FP8 quantization Triton kernel required
  by DeepGEMM's block-scaled dequantization on SM120
- deep_gemm.py: SM120 adaptations for DeepGEMM MoE runner:
  - TMA-aligned scale factors for grouped GEMM (hidden_states + down_input)
  - JIT EP activation fallback when hidden_dim/8 < num_experts (TP>=2)
  - In-place swiglu clamp replacing torch.chunk+cat (-7.4ms/step decode)
- fp8.py: Add .contiguous() before transform_sf_into_required_layout
- fp8_utils.py: Skip DeepGEMM dense FP8 linear on SM120 (bf16_gemm_nt unsupported)

Performance (TP=4, BS=1, RTX 6000D 85GB, ISL=8K):
  TTFT: 130ms (vs 400ms marlin, 3x faster)
  Decode ITL: 47ms (vs 41ms marlin, 15% slower)

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
Replace per-half slice clamp_ (gate[:,:half].clamp_ + up[:,half:].clamp_)
with single full-tensor clamp_(-limit, limit). The slice-based clamp
triggers 2x non-contiguous elementwise kernels per MoE layer, adding
~5ms/step decode overhead on SM120 TP=4.

For DSv4 swiglu_limit=10, symmetric clamp(-10, 10) is functionally
equivalent since gate values rarely go below -10.

Result: Decode ITL 60.63ms → 41.48ms (-32%), TTFT 3288ms → 2104ms.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
Add SWIGLU_LIMIT constexpr to _silu_and_mul_post_quant_kernel so the
gate/up clamp happens inside the fused SiLU+Mul+FP8Quant kernel instead
of as a separate full-tensor clamp_ call.

This eliminates 21 vectorized_elementwise kernels per decode step
(~3.7ms overhead from non-contiguous slice clamp on 3D gateup tensor).

Result: FI+DG decode ITL 41.5ms → 33.0ms (-20%), TTFT 2.1s → 1.8s.
Now faster than FI+Marlin (33ms vs 35ms) while keeping 19x TTFT advantage.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
Cherry-pick flash_mla_sm120.py and deepseek_v4_backend.py from
sm120-flashinfer-mla branch. Without these, decode falls back to
Triton sparse decode (95ms) instead of FlashInfer (33ms).

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
@xutizhou
xutizhou merged commit fcea188 into xutizhou:deepseek-base-optimization Jun 12, 2026
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