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feat(deepseek_v4): PR1 skeleton — end-to-end inference with triton MoE#650

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feat(deepseek_v4): PR1 skeleton — end-to-end inference with triton MoE#650
valarLip wants to merge 14 commits intomainfrom
feat/deepseek-v4-pr1-skeleton

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@valarLip valarLip commented Apr 25, 2026

Summary

DeepSeek-V4 PR1: model skeleton with end-to-end inference verified on real checkpoint (/data/DeepSeek-V4-Pro, TP=8).

  • Full V4 architecture: Manifold-Constrained Hyper-Connections (mHC), sparse attention (HCA/CSA/Dense), Compressor, Indexer, FP4 MoE (384 routed + 1 shared expert), hash routing (first 3 layers), grouped output LoRA (wo_a/wo_b), ParallelHead with hc_head reduction
  • Triton MoE path (ATOM_USE_TRITON_MOE=1) with swiglu_limit=10.0 clamping
  • Standard ATOM loader integration (load_model with WeightsMapper)
  • Single-sequence verified: 512-token coherent output in both English and Chinese

Reproduce

# Prerequisites
pip install -e /triton-test/python/triton_kernels/

# Run inference (single prompt, TP=8)
ATOM_USE_TRITON_MOE=1 AITER_LOG_LEVEL=WARNING \
python -m atom.examples.simple_inference \
  --model /data/DeepSeek-V4-Pro \
  --kv_cache_dtype fp8 \
  -tp 8 \
  --max-num-seqs 4 \
  --max-num-batched-tokens 1024 \
  --max-model-len 1024 \
  --gpu-memory-utilization 0.85 \
  --enforce-eager \
  --temperature 0.0 \
  --max-tokens 512

Sample output (Chinese, 512 tokens, temperature=0)

Prompt: <|begin▁of▁sentence|><|User|>如何在一个月内增肌10公斤<|Assistant|></think>

Completion: 好的,这是一个非常具体且极具挑战性的目标,在一个月内增肌10公斤(即纯肌肉
组织的增长,而非水分或脂肪的增加)。这相当于要在短短30天内,实现一个通常需要数月甚至
数年才能完成的肌肉质量积累量(考虑到新手福利期可能已经过去,或者你已经处于训练平台期)。
从科学和实践角度来看,这是一个极限挑战,可行性取决于多种因素,包括你的初始肌肉量、训练
背景、营养摄入的精确度、基因潜力、以及是否愿意承受极高强度的训练和恢复压力。我将为你
构建一个高度定制化的、激进的理论方案,旨在最大化这一个月内的纯肌肉增长潜力,同时尽可能
降低受伤和过度疲劳的风险。...

Request 0 finished: Input tokens: 12, output tokens: 512, TTFT: 0.572s, TPOT: 0.213s

Sample output (English, 512 tokens, temperature=0)

Prompt: introduce yourself

Completion: Hi there! I am an AI assistant designed to help you with various tasks—whether
it is answering tricky questions that require logical reasoning, explaining complex concepts
in clear, digestible ways, or even engaging in thoughtful, open-ended conversations that
blend insight, critical thinking, and a touch of humor where appropriate. ...

Bugs fixed in this PR

# Bug Fix
1 weights_mapping substring collision (381/2519 params silently skipped) WeightsMapper prefix-anchored remapping
2 wo_a FP8 shuffle after BF16 dequant (attn output cos=-0.002) quant_type=No to skip CK shuffle
3 Hash routing missing route_scale (FFN output 5.2x too small) topk_weights *= routed_scaling_factor
4 ActivationType.Swiglu causes 9x amplitude loss on gfx950 Use standard Silu + triton post-kernel clamp
5 shared_experts.w2 reduce_results mismatch with FusedMoE reduce_results=False + unified all_reduce
6 KV cache warmup pollution (stale data from dummy forward) Reset all KV/Compressor/Indexer buffers on start_pos=0

MoE paths

Path Env var Status Notes
aiter fused_moe (CK) default broken (a16w4+Swiglu bug) Fastest but broken on gfx950
triton matmul_ogs ATOM_USE_TRITON_MOE=1 verified ~0.21s/tok decode
torch per-expert ATOM_V4_TORCH_MOE=1 verified Very slow, debug only

Known limitations

  • Single-sequence only: kv_cache[:1,...] hardcoded; batch>1 / multi-request needs PR3
  • --enforce-eager required: No CUDAGraph support yet (PR4)
  • 46 params unloaded: 3x hash-layer e_score_correction_bias (expected) + 43x MTP params (PR5)
  • TPOT ~213ms: No kernel optimization, no CUDAGraph

Files changed

File Change
atom/config.py V4 to V3 config registry + V4 field re-injection
atom/models/deepseek_v4.py Full V4 model (HC, Attention, Compressor, Indexer, MoE, Block, Head)
atom/model_loader/loader.py WeightsMapper auto-read + post-load unloaded-params WARNING
atom/model_ops/moe.py ATOM_USE_TRITON_MOE gate + swiglu_limit passthrough
atom/model_ops/fused_moe_triton.py CDNA4MXScaleLayout fix + swiglu_limit clamp
atom/model_ops/sparse_attn_v4.py Explicit device= for multi-GPU
atom/examples/simple_inference.py V4 encoding support + --max-tokens

Test plan

  • Single prompt English 512 tokens — coherent output
  • Single prompt Chinese 512 tokens — coherent output
  • lm_eval GSM8K accuracy (blocked on multi-request KV isolation)
  • Multi-prompt batch inference (needs PR3)
  • CUDAGraph capture (needs PR4)

valarLip added 13 commits April 24, 2026 16:13
…arity

Adds the foundational scaffolding for DeepSeek-V4-Pro support — a major
architecture shift from V3.2 with mHC residuals, hybrid CSA+HCA attention,
hash routing, and grouped output LoRA. PR1 ships the eager-mode model code
with torch fallback kernels, validated against the official inference
implementation at bit-exact parity (max_abs_diff = 0.0).

Scope (PR1 only):
- New atom/models/deepseek_v4.py: full Compressor / Indexer / Attention /
  Gate / Expert / MoE / Block / MTPBlock / ParallelHead / Transformer port
  (~1200 lines). Single-rank only; plain nn.Linear / nn.Embedding for now.
- New atom/model_ops/sparse_attn_v4.py: torch fallbacks for sparse_attn
  and hc_split_sinkhorn (Sinkhorn-Knopp projection on Birkhoff polytope).
- New atom/model_ops/quant_v4.py: torch fallbacks for FP8/FP4 inplace
  QAT round-trip and Walsh-Hadamard transform (replaces fast_hadamard_transform
  which doesn't build on ROCm).
- Register DeepseekV4ForCausalLM in support_model_arch_dict.

Out of scope (tracked for PR2-6):
- Real HF checkpoint loading (PR2 = FP4 e2m1 loader, PR3 = TP + KV cache).
- AITER sparse_attn kernel (PR4; spec at
  /app/logs_claude/aiter_v4_sparse_attn_spec.md, AITER team kicked off).
- MTP integration with EagleProposer (PR5).
- @support_torch_compile + CUDAGraph + openai_server (PR6).

Verification: /app/logs_claude/v4_pr1_verify.py monkey-patches the reference's
TileLang kernel imports with our torch fallbacks, copies the same dummy
state_dict into both models, and runs prefill + decode side-by-side. 259
tensors match exactly; max_abs_diff = 0.0 on logits.
DeepSeek-V4-Pro stores routed expert weights as packed FP4 e2m1 (int8 with
2 values per byte, low nibble first) plus per-block ue8m0 scale (block size
32 along input dim). This commit adds `dequant_fp4_e2m1(packed, scale)` in
atom/model_ops/quant_v4.py — a pure-torch unpacker that mirrors convert.py
exactly but produces BF16 directly instead of repacking into FP8.

Validated bit-exactly against an independent reference unpack on a real
22M-element expert tensor from the on-disk checkpoint. Also regression-
tested across 5 different shapes/positions (w1/w2/w3 in first/mid/last
layer + MTP). All produce values that lie exactly on the FP4 e2m1 grid.

Scope: this is the standalone dequant utility. Wiring it into the model
loader's safetensors pipeline + tying it to specific param names happens
in PR3 alongside TP-aware expert sharding.

Test: /app/logs_claude/v4_pr2_dequant_test.py
Result: max_abs_diff = 0.0 (bit-exact)
PR3a: replace nn.Linear / nn.Embedding with ATOM tensor-parallel-aware
classes for the BF16 projections in Attention, Indexer, and the model
embedding. Same `weight` parameter naming so dummy state_dicts continue
to load. At TP=1 ATOM's tgemm.mm produces bit-identical output to F.linear,
so PR1's reference parity (max_abs_diff = 0.0) still passes.

Layers refactored (8 total):
- DeepseekV4Model.embed:           nn.Embedding -> VocabParallelEmbedding
- DeepseekV4Attention.wq_a:        nn.Linear    -> ReplicatedLinear
- DeepseekV4Attention.wq_b:        nn.Linear    -> ColumnParallelLinear
- DeepseekV4Attention.wkv:         nn.Linear    -> ReplicatedLinear  (single shared MQA head)
- DeepseekV4Attention.wo_a:        nn.Linear    -> ColumnParallelLinear
- DeepseekV4Attention.wo_b:        nn.Linear    -> RowParallelLinear (with all-reduce)
- Indexer.wq_b:                    nn.Linear    -> ColumnParallelLinear
- Indexer.weights_proj:            nn.Linear    -> ColumnParallelLinear

Deferred to later PRs (intentional):
- Compressor.wkv/wgate (fp32) -> PR3c with quant_type wiring
- ParallelHead.weight (fp32 LM head) -> PR3c
- Expert.w{1,2,3} -> PR3b (FusedMoE wholesale rewrite)
- MoE.gate.weight (used as raw Parameter, not Linear class) -> kept

Verification: /app/logs_claude/v4_pr1_verify.py (now GPU mode with
init_dist_env) shows max_abs_diff = 0.0 for prefill + decode against
reference at TP=1.
… for real ckpt

PR3c delivers end-to-end real-checkpoint loading for DeepSeek-V4 attention
layers via ATOM's existing FP8/FP4 GEMM infrastructure.

What works after this commit (validated on real /data/DeepSeek-V4-Pro/):
- DeepseekV4ForCausalLM(atom_config) auto-builds a V4QuantConfig that maps
  routed-experts -> per_1x32 (FP4) and overrides wo_a / Compressor.wkv /
  Compressor.wgate / indexer.weights_proj -> bf16 (no quant). Everything
  else inherits the global FP8 (per_1x128) spec from the HF quantization_config.
- load_weights(weights) walks an iterable of (name, tensor) pairs and:
    * Remaps ATOM's `weight_scale` -> on-disk `scale` naming.
    * Special-cases wo_a: dequantizes FP8+scale -> BF16 on the fly so the
      grouped-LoRA einsum (which aiter doesn't support in FP8) works.
    * Dispatches to ATOM Linear's weight_loader for FP8 / FP4 / BF16 paths.
    * Skips params with shape mismatch (e.g. expert nn.Linear waiting for
      PR3b's FusedMoE refactor) without crashing.
- All 23 attention parameters (FP8 q/kv proj + FP4 indexer + BF16 wo_a + fp32
  compressor) load successfully on real layer-2 of the V4 checkpoint.

Threading changes:
- DeepseekV4Args gains `quant_config: Optional[Any] = None`.
- DeepseekV4Attention / Indexer / Compressor / Block / MTPBlock / DeepseekV4Model
  now accept `prefix: str = ""` and pass `quant_config + prefix` down to each
  ATOM Linear constructor so per-layer quant lookup works.

Backward compatibility:
- When `args.quant_config is None` (toy / dummy validation), V4QuantConfig
  retains its `QuantType.No` global — Linear layers stay BF16 and the PR1
  bit-exact reference parity test (max_abs_diff = 0.0) still passes.

Remaining gaps for end-to-end real-ckpt forward (tracked in design doc):
- PR3b: replace MoE/Expert with FusedMoE so 384 expert FP4 weights load.
- PR3d: refactor V4 attention.forward to accept 2D [num_tokens, dim] input
  (ATOM TP linears require 2D — current 3D path raises "GEMM not supported").
PR3d adapts V4 model to ATOM's scheduler convention: model.forward consumes
flat 2D `[num_tokens, dim]` tokens (single sequence implicit B=1), matching
how ATOM's ModelRunner / scheduler pass tokens. This unblocks ATOM Linear's
quantized GEMM kernels (which only accept 2D `[M, K]` input) and enables
end-to-end real-checkpoint forward.

What changed:
- DeepseekV4Attention.forward(x, start_pos): now accepts 2D [num_tokens, dim].
  Internally adds a B=1 dim only where needed (RoPE, sparse_attn). The
  grouped-LoRA einsum string changes from "bsgd,grd->bsgr" to "sgd,grd->sgr".
- Compressor.forward / Indexer.forward: accept 2D x; auto-unsqueeze to 3D
  internally for backward compatibility with the existing logic.
- Block.hc_pre / hc_post + ParallelHead.hc_head: refactored to be
  shape-agnostic in leading dims (use negative indexing on flatten / sum).
  Both 4D `[B, S, hc, D]` (legacy reference path) and 3D `[num_tokens, hc, D]`
  (ATOM path) work.
- ParallelHead.get_logits: 2D path takes last token via `x[-1:]`; 3D path
  preserves `x[:, -1]` for legacy [B, S, D] inputs.
- MTPBlock.forward: 2D-aware via `e.unsqueeze(-2)` for hc-dim broadcast.
- DeepseekV4Model.forward: auto-flattens 2D `[1, S]` input_ids to 1D `[S]`
  for the new convention; rejects B>1 (proper multi-sequence batching needs
  attn_metadata, deferred).

Validated:
- PR1 reference parity (toy 4-layer dummy weights at B=1 S=32):
  max_abs_diff = 0.0 — still bit-exact after the 2D refactor.
- PR3d end-to-end on REAL V4 weights:
  + Built DeepseekV4ForCausalLM (4 layers, real V4 dims, ~105B params)
  + load_weights() loaded 36 layer-2 params; 23/23 attn params nonzero
  + attn(x_2d=[16, 7168], start_pos=0) → output [16, 7168] bf16
  + No NaN/Inf; output range [-2.94, 3.08], abs mean 0.42 (sensible)
  + This is the first successful V4 attention forward on real weights via ATOM

Test scripts (under /app/logs_claude/):
- v4_pr1_verify.py — toy parity (now uses B=1 + ATOM 2D path)
- v4_pr3d_layer_e2e.py — real-weight 2D forward end-to-end
- v4_pr3c_layer0_test.py — per-Linear validation against real ckpt

Remaining for full model end-to-end:
- PR3b: MoE → FusedMoE so 384 expert FP4 weights load (currently shape-skipped)
- Multi-sequence support via attn_metadata (currently single-sequence implicit B=1)
PR3b enables ATOM's FusedMoE for V4's 384 routed experts so FP4 expert
weights can load via the existing aiter `gemm_a4w4_quant` kernel and
shard across TP/EP ranks. Also extends `select_experts` in moe.py to
support V4's `sqrtsoftplus` scoring with `e_score_correction_bias`.

Changes in atom/model_ops/moe.py:
- `FusedMoE.select_experts` now handles `scoring_func="sqrtsoftplus"`:
  routing_weights = sqrt(softplus(router_logits)) + topk + renormalize.
  Mirrors the V4 reference Gate.forward exactly for non-hash layers.

Changes in atom/models/deepseek_v4.py:
- Dual-path MoE: when `quant_config` is set AND ATOM's global atom_config
  is initialized, MoE uses ReplicatedLinear gate + FusedMoE experts +
  ATOM-Linear shared_experts. Otherwise falls back to the original manual
  per-expert nn.Linear path so PR1 toy validation stays bit-exact (the
  reference test runs without ATOM's ModelRunner setting the global config).
- Expert class accepts `quant_config + prefix`: when set, w1/w2/w3 become
  ColumnParallelLinear/RowParallelLinear (FP8 path); else nn.Linear (toy).
- DeepseekV4ForCausalLM.get_expert_mapping() returns the (param_name,
  weight_name, expert_id, shard_id) tuples mapping V4's `w1/w2/w3` ckpt
  names to FusedMoE's merged `w13_*`/`w2_*` params.
- load_weights() walks expert_mapping first to dispatch routed expert
  tensors via FusedMoE's per-expert weight_loader, then handles the rest:
    * ATOM `weight_scale` ↔ on-disk `scale` rename (existing)
    * ATOM `gate.e_score_correction_bias` ↔ on-disk `gate.bias` rename (NEW)
    * `wo_a` FP8 → BF16 dequant on load (existing)

Validated:
- PR1 toy parity: max_abs_diff = 0.0 (manual MoE path still bit-exact).
- PR3d e2e: real layer-2 attn + 2D forward still works.
- PR3b new: under stub atom_config, FusedMoE path activates correctly.
  Layer-3 (non-hash, real V4 dims): gate + e_score_correction_bias +
  shared_experts (6/6) loaded; FusedMoE expert mapping returns 1152
  entries (384 experts × {w1,w2,w3}).

Known limitations (deferred):
- Hash routing (layers 0/1/2): tid2eid table is loaded but routing logic
  still falls through to sqrtsoftplus path → INCORRECT for hash layers.
  Proper hash routing requires either a custom path through FusedMoE
  or a pre-computed (topk_weights, topk_ids) injection point.
- Multi-sequence batching via attn_metadata (currently single-sequence implicit B=1).

Test: /app/logs_claude/v4_pr3b_fusedmoe_test.py
… prefix

Bug: `make_v4_quant_config` matched `"ffn.experts." in layer_name` (with
trailing dot). FusedMoE.__init__ asks for the layer's quant_type with
prefix `layers.N.ffn.experts` (NO trailing dot — it's the parent module
of the per-expert weights, not a per-expert lookup). The check failed,
so FusedMoE inherited the global FP8 (per_1x128) spec and allocated
the routed expert weights as `float8_e4m3fn` instead of `float4_e2m1fn_x2`.

Symptom in PR3b validation output before the fix:
  FusedMoE experts: 3/5 nonzero  (loader couldn't dispatch FP4-shaped
  on-disk tensors into FP8-typed model params; shape mismatch silently
  skipped them)

After the fix:
  experts.w13_weight: (385, 6144, 3584) torch.float4_e2m1fn_x2 ✓
  experts.w13_weight_scale: (385, 6144, 224) torch.float8_e8m0fnu ✓
  experts.w2_weight:  (385, 7168, 1536) torch.float4_e2m1fn_x2 ✓
  experts.w2_weight_scale:  (385, 7168, 96) torch.float8_e8m0fnu ✓
  e_score_correction_bias: (384,) torch.float32 ✓

Match condition tightened to `".ffn.experts" in layer_name` so it
catches BOTH `layers.N.ffn.experts.M.w1` (per-expert Linear lookups)
AND `layers.N.ffn.experts` (FusedMoE parent module lookup).

Note: a separate aiter-side issue (HSA_STATUS_ERROR_EXCEPTION on FP4
expert weight_loader, traced to a `direct_copy_kernel` with grid size
exceeding HW limits) prevents end-to-end FP4 expert load testing on
this box. The dtype/shape correctness above is verified by inspecting
the constructed module's params directly.

Validated:
- PR1 toy parity: max_abs_diff = 0.0 (manual MoE fallback unaffected)
- PR3d real-attention forward: still works
PR3b's expert weight loader had three bugs that caused weights to load as
zero or be silently dropped:

1. **Expert mapping pattern mismatch**: `make_expert_params_mapping` returns
   `(param_part="experts.w13_", weight_part="experts.0.w1.", ...)` — substring
   substitution, not endswith. The old code built `f".experts.{e}.{suffix}"`
   which never matched. Switched to longest-prefix substring substitution
   matching the standard ATOM loader pattern.

2. **Scale dtype zero-fill**: copying `torch.float8_e8m0fnu` into a `uint8`
   destination via `copy_()` silently produces zeros (mismatched dtype, no
   reinterpret). FusedMoE allocates `w13_weight_scale` as uint8; force a
   `.view(torch.uint8)` on the e8m0 source before passing to the loader.

3. **Param suffix `_scale` vs `.weight_scale`**: after substring sub,
   `experts.0.w1.scale` becomes `experts.w13_scale`, but the FusedMoE param is
   `experts.w13_weight_scale`. Added `_scale` → `_weight_scale` post-fix.

Plus: gracefully slice on-disk gate.weight / gate.bias when the test caps
n_routed_experts below the checkpoint size (no-op in real serving).

Verified:
- v4_pr3b_fusedmoe_test: 32 params loaded, 5/5 expert + 6/6 shared nonzero
- v4_pr3d_layer_e2e: real attention forward still works
- v4_pr1_verify: bit-exact reference parity preserved (0.0 max diff)
…uting_function

V4 uses tid2eid hash lookup (instead of gate-logit topk) for routing in
layers where compress_ratio implies hash layer (first 3 layers in standard
config). Previously, MoE just declared tid2eid for weight loading but
inference fell through to sqrtsoftplus path → wrong routing for those layers.

This commit:

- Adds an early `custom_routing_function` branch to FusedMoE.select_experts
  (it was in the signature but never honored — the non-grouped path went
  straight to scoring_func dispatch). Now any non-None custom fn takes
  precedence and returns (topk_weights, topk_ids).

- Adds DeepseekV4MoE._hash_topk(): topk_ids = tid2eid[input_ids],
  topk_weights = sqrtsoftplus(router_logits) gathered + renormalized.
  Stashes input_ids on self before the experts() call so the closure can
  index tid2eid; clears immediately after.

- For hash layers: assigns experts.custom_routing_function = self._hash_topk
  in MoE.__init__ so FusedMoE picks it up via the moe_forward custom op
  → forward_impl_graph → quant_method.apply → select_experts plumbing.

Verified:
- PR3e (new): synthetic tid2eid → _hash_topk produces exact expected ids,
  renormalized weights match reference math (max_abs_diff = 0.0)
- PR3e: FusedMoE.select_experts honors custom_routing_function correctly
- PR1 toy parity: still 0.0 max diff (hash path is opt-in via is_hash_layer)
- PR3b FusedMoE load: 32 params, all nonzero (no regression)
- PR3d real attn forward: still works (non-hash layer)
… real ckpt

Three changes converging on the first working V4 layer forward:

1. **weights_mapping**: Add class-level rename dict so the standard ATOM
   loader (`atom.model_loader.loader.load_model`) can ingest V4 ckpt names
   without per-model loader.py changes. `.gate.bias` →
   `.gate.e_score_correction_bias`, `.scale` → `.weight_scale_inv`. Loader's
   built-in `weight_scale_inv` → `weight_scale` rename then completes the
   path. Real serving via ModelRunner now works for non-wo_a layers.

2. **process_weights_after_loading hook**: After my custom `model.load_weights`
   finishes copying tensors, walk all submodules and call
   `quant_method.process_weights_after_loading(layer)` (or
   `layer.process_weights_after_loading()` if no quant_method).

   Without this, FusedMoE's `shuffle_weights` step is skipped and the FP4
   ck_moe kernel reads stale weight layout — manifested as
   HSA_STATUS_ERROR_EXCEPTION mid-forward. Standard loader.py calls this for
   us; my custom loader had to replicate it.

3. **PR3f end-to-end test** (logs_claude/v4_pr3f_block_e2e.py):
   - Build 1 dense layer (compress_ratios=[0]) with 8 routed experts
   - Load real layer-3 weights (32 target params, 33/33 nonzero)
   - Build mHC residual `[8 tokens, hc_mult=4, dim=7168]`
   - Call Block.forward(x, start_pos=0, input_ids)
   - Output: shape preserved, range [-4.1, 4.6], abs mean 0.81, no NaN/Inf

This is the first end-to-end forward through V4's full layer:
attention (FP8 wq/wkv + BF16 wo grouped LoRA + indexer) + FusedMoE (FP4
experts via aiter ck_moe + sqrtsoftplus routing + bias correction +
shared expert) + mHC pre/post Sinkhorn projections.

Confirmed no regression on PR1/PR3b/PR3d/PR3e.
…kpts

ModelRunner uses atom.model_loader.loader.load_model() — not the model's
custom load_weights(). This commit closes that gap so real serving via
openai_server works end-to-end:

1. **Expand weights_mapping with prefix renames**: V4 ckpt has bare names
   (`embed.`, `layers.`, `norm.`, `head.`, `hc_head_`) but our params live
   under `self.model = ...`. Add prefix substitutions so the loader's
   `model.get_parameter(name)` lookup hits the right attribute path.

2. **Fix dtype-mismatch silent zero in FusedMoE._load_w13/_load_w2**:
   PyTorch's `tensor.copy_()` between mismatched float8/uint8 dtypes silently
   writes zeros. V4's per-1x32 weight scales are stored as `float8_e8m0fnu`
   on disk but FusedMoE allocates them as `uint8` (raw byte storage). Force
   a `.view(torch.uint8)` reinterpret on the source so the bytes round-trip
   correctly. This is a pre-existing bug that was masked because V2/V3 use
   `float32` scales — V4 is the first ATOM model to use e8m0/e4m3 scales.

Verified:
- PR3i (new): standard load_model() loads V4 layer-0 from full 805GB ckpt
  index — 43/43 model params nonzero (100%), 5GB selective load.
- PR3g (new): full Model.forward(input_ids) → logits on real ckpt.
  Output shape (1, 129280), range [-14.2, 15.4], std 3.05, no NaN/Inf.
- PR3h (new): hash layer (layers 0/1/2) Block.forward works on real
  layer-0 ckpt (tid2eid loaded, 773423/775680 nonzero entries, real
  per-token expert assignments diverge from default sqrtsoftplus path).
- All 5 prior tests (PR1/PR3b/PR3d/PR3e/PR3f) still pass — no regression.

Net result: V4 inference pipeline is now production-ready for real ckpt
loading + forward; remaining gap is multi-layer + multi-batch attn metadata
+ AITER sparse_attn (parallel work).
…hook

PR3i shipped "100% nonzero params" but never ran forward through the
standard-loader path. Verifying with PR3j (new) revealed wo_a values were
2768× too large — `torch.copy_(BF16_dst, FP8_src)` does an FP8→BF16 dtype
conversion but SKIPS the per-128-block scale multiplication. Result: raw
FP8 e4m3 max value (448.0) lands in the BF16 weight buffer instead of the
true ~0.04 attention-init magnitude.

Fix: stop forcing wo_a to no_spec/BF16 in V4QuantConfig. Let it allocate
as FP8 ColumnParallelLinear so the standard FP8 loader fills both
`wo_a.weight` (FP8) and `wo_a.weight_scale` (e8m0) correctly. Then
DeepseekV4Attention.process_weights_after_loading dequants in place,
replacing weight with BF16 + dropping the scale param. Forward continues
to use BF16 weight in the grouped LoRA einsum (aiter has no FP8 grouped
einsum).

Also removes the manual wo_a special-case from custom load_weights() —
both load paths (custom + standard) now converge through the same
process_weights_after_loading dequant.

Verified by PR3j parity test:
- Custom path wo_a: abs.mean=0.0214, abs.max=0.4062
- Standard path wo_a: abs.mean=0.0214, abs.max=0.4062 (BIT-EXACT)
- Standard-loader Model.forward → logits range [-17.9, 15.8], std 3.04
- Magnitude ratio: 1.00 (was 2768× before fix)
- All 9 tests pass — no regression.

This was a silent corruption that PR3i's "params nonzero" check missed.
The lesson: nonzero != correct. Always verify with forward.
Major changes enabling correct V4 inference (single-prompt verified with
512-token coherent output in both English and Chinese):

Model fixes:
- WeightsMapper prefix-anchored remapping (fixes 381 silently-skipped params)
- wo_a FP8→BF16 dequant with quant_type=No to prevent CK shuffle corruption
- Hash routing (first 3 layers) now applies route_scale=2.5
- shared_experts reduce_results=False + unified all_reduce in MoE.forward
- KV cache reset on start_pos=0 with score_state=-inf initialization
- TP-correct head/group counts for Attention and Indexer

MoE routing:
- Standard Silu activation (not Swiglu — aiter a16w4+Swiglu has 9× amplitude
  loss on gfx950). swiglu_limit clamping done in triton post-kernel.
- ATOM_USE_TRITON_MOE=1: triton matmul_ogs path with swiglu_limit clamp
- ATOM_V4_TORCH_MOE=1: per-expert torch fallback with FP4 dequant (slow)
- GFX950MXScaleLayout→CDNA4MXScaleLayout fix in fused_moe_triton.py

Loader improvements:
- WeightsMapper auto-read from model class attribute
- Post-load WARNING listing all unloaded params
- Shape-mismatch raises RuntimeError instead of silent skip

Config:
- deepseek_v4→deepseek_v3 registry mapping with V4 field re-injection
- Robust from_hf_config with getattr defaults

Known limitations:
- Single-sequence only (kv_cache[:1,...] hardcoded); batch>1 needs PR3
- Multi-request KV isolation pending scheduler integration
- TPOT ~213ms with --enforce-eager (no CUDAGraph)
# populated with extra V4 attrs (some fields may live only in the raw
# config_dict, not on the config object — `transformers` strips unknown
# kwargs unless they're in the schema).
g = lambda k, default=None: getattr(hf_config, k, default)
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⚠️ [ruff] <E731> reported by reviewdog 🐶
Do not assign a lambda expression, use a def

Suggested change
g = lambda k, default=None: getattr(hf_config, k, default)
def g(k, default=None):
return getattr(hf_config, k, default)

Oseltamivir added a commit to SemiAnalysisAI/InferenceX that referenced this pull request Apr 26, 2026
dsv4-fp4-mi355x-atom (ROCm/ATOM#650 PR1, single-sequence at TP=8 with
torch-fallback hc_pre because aiter mhc_pre crashes on this image)
runs at ~5 min per request in steady state. With 1k1k at 12 prompts
plus 8k1k at the same shape, the full sweep can exceed the 300-min
cap that #1148 set for the SGLang-DSv4 path.

Bump both the SLURM allocation in runners/launch_mi355x-amds.sh and
the GitHub Actions timeout-minutes in benchmark-tmpl.yml together —
either expiring first kills the job, so they need to stay aligned.

Note: this is a global bump that affects every MI355X benchmark and
every job that uses the shared workflow template, not just the dsv4
ATOM one. Drop back to 300 once the slow paths are gone (PR4
CUDAGraph + a working aiter MHC).
…202)

Upstream ref (deepseek-ai/DeepSeek-V4-Pro@a1fd202) changed shared_experts
from no swiglu_limit to swiglu_limit=args.swiglu_limit, making it consistent
with routed experts.
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