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nvfp4-megamoe-kernel/single_shot_inference.py

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#!/usr/bin/env python3
"""Single-shot DSV4-Pro inference — Full 61-layer pipeline, 8-GPU.
This is a reference implementation that exercises the production kernel
stack end-to-end. It should be usable as ground truth when integrating
into vLLM or SGLang.
Architecture (paper §2):
X_l → mHC.pre_block → RMSNorm → Attention → F_attn → mHC.post_block → X_mid
X_mid → mHC.pre_block → RMSNorm → FFN(MoE) → F_ffn → mHC.post_block → X_{l+1}
Components exercised:
- mHC (Manifold-Constrained Hyper-Connections) — proper Sinkhorn-Knopp
- Low-rank Q projection (q_a → q_b) + KV projection (MQA, 1 KV head)
- Partial RoPE (last 64 dims, GPT-J interleaved)
- Production FMHA kernel (6-warp multi-tile, C API + ctypes)
- Inverse RoPE on attention output (paper §2.3.3)
- Grouped output projection (wo_a BMM + wo_b NVFP4)
- Routed MoE (384 experts, top-6, hash + dense routing, SwiGLU clamp)
- Shared expert (NVFP4 gate/up/down)
- RMSNorm (pre-norm before each sub-block)
- KV cache across decode steps
Attention type simplification for this single-shot test:
For short sequences (seq_len ≤ sliding_window=128), ALL attention
types (CSA/HCA/SWA) reduce to dense attention over the full KV cache.
CSA's compressed branch and indexer are only needed for long sequences
where seq_len > sliding_window. HCA is dense over compressed entries,
but at short sequence lengths, the compressed sequence is trivially
small. So we use dense MQA attention over the full KV for all layers.
This is mathematically correct for short sequences and exercises the
FMHA kernel properly.
Usage (on B200):
source /root/dsv4-nvfp4-workspace/venv/bin/activate
cd /root/dsv4-nvfp4-workspace/kernel
python3 single_shot_inference.py
"""
import os, sys, time, json, math, argparse
import torch
from pathlib import Path
# =====================================================================
# Configuration
# =====================================================================
def parse_args():
p = argparse.ArgumentParser(description='DSV4 Single-Shot Inference')
p.add_argument('--no-inverse-rope', action='store_true', help='Skip inverse RoPE on attention output')
p.add_argument('--skip-moe', action='store_true', help='Only use shared expert (skip routed)')
p.add_argument('--max-tokens', type=int, default=512, help='Max new tokens to generate')
p.add_argument('--prompt', type=str, default=None, help='Override prompt')
return p.parse_args()
_args = parse_args()
CHECKPOINT_DIR = "/root/nvidia-meeting/DeepSeek-V4-Pro-NVFP4"
MAX_NEW_TOKENS = _args.max_tokens
SYSTEM_PROMPT = "You are a helpful, harmless, and honest AI assistant. Answer the user's questions accurately and concisely. If you're unsure about something, say so rather than guessing. Follow the user's instructions carefully and ask for clarification when needed. Always respond in the same language the user is writing in."
PROMPT = _args.prompt or "The capital of France is"
NUM_GPUS = 8
SKIP_ROUTED_MOE = _args.skip_moe # If True, only use shared expert (debug)
INVERSE_ROPE = not _args.no_inverse_rope # If False, skip inverse RoPE on attention output (diagnostic)
MHC_DIAG = False # If True, print per-layer mHC diagnostics (B_l row/col sums, C_l values)
# When True: applies inverse RoPE at query position → converts absolute→relative
# When False: leaves relative position encoding intact for output projection
# DSV4 partial RoPE only affects last 64/512 dims; first 448 are always un-RoPE'd
print(f"Config: INVERSE_ROPE={INVERSE_ROPE}, SKIP_ROUTED_MOE={SKIP_ROUTED_MOE}, MAX_NEW_TOKENS={MAX_NEW_TOKENS}")
# =====================================================================
# NVFP4 dequantization — matches checkpoint format exactly
# =====================================================================
FP4_LUT = torch.tensor([0., 0.5, 1.0, 1.5, 2.0, 3.0, 4.0, 6.0]) # E2M1 magnitudes
def dequant_nvfp4_weight(weight, weight_scale, weight_scale_2):
"""Dequantize NVFP4 weight to BF16.
weight: (out_dim, in_dim//2) uint8 — 2 FP4 values per byte
weight_scale: (out_dim, in_dim//16) E4M3 — per-16-element block scale
weight_scale_2: (out_dim, 1) float32 — per-row global scale
"""
out_dim = weight.shape[0]
in_packed = weight.shape[1]
in_features = in_packed * 2
low = (weight & 0x0F).to(torch.int8)
high = (weight >> 4).to(torch.int8)
low_sign, low_idx = (low >> 3).bool(), (low & 0x07).long()
high_sign, high_idx = (high >> 3).bool(), (high & 0x07).long()
lut = FP4_LUT.to(device=weight.device, dtype=torch.float32)
low_f = lut[low_idx] * torch.where(low_sign, -1.0, 1.0)
high_f = lut[high_idx] * torch.where(high_sign, -1.0, 1.0)
w_f = torch.stack([low_f, high_f], dim=-1).reshape(out_dim, in_features)
scale_f = weight_scale.float() * weight_scale_2.float()
scale_expanded = scale_f.repeat_interleave(16, dim=1)
return (w_f * scale_expanded).bfloat16()
def nvfp4_linear(x, weight, weight_scale, weight_scale_2):
"""BF16 linear with NVFP4 dequant."""
w = dequant_nvfp4_weight(weight, weight_scale, weight_scale_2)
return torch.nn.functional.linear(x, w)
# =====================================================================
# RMSNorm — matches dsv4/layers/norm.py
# =====================================================================
class RMSNorm:
def __init__(self, hidden_size, eps=1e-6, device='cuda:0'):
self.eps = eps
self.weight = torch.ones(hidden_size, dtype=torch.float32, device=device)
def forward(self, x):
"""x: (T, H) BF16 → (T, H) BF16"""
x_f = x.float()
rms = x_f.pow(2).mean(dim=-1, keepdim=True).add(self.eps).rsqrt()
return (x_f * rms * self.weight).to(torch.bfloat16)
# =====================================================================
# mHC — proper Sinkhorn-Knopp implementation
# =====================================================================
class mHCBlock:
"""Wrapper around dsv4.layers.mhc.mHCLayer for single-shot inference.
Uses the production mHCLayer implementation with proper Sinkhorn-Knopp.
"""
def __init__(self, hidden_dim=7168, n_hc=4, sinkhorn_iters=20, device='cuda:0'):
from dsv4.layers.mhc import mHCLayer
self._impl = mHCLayer(
hidden_dim=hidden_dim, n_hc=n_hc,
t_max_sinkhorn=sinkhorn_iters,
device=device, dtype=torch.bfloat16)
self.device = device
self.n_hc = n_hc
self.hidden_dim = hidden_dim
def load_from_checkpoint(self, fn, base, scale):
"""Load from checkpoint tensors.
fn: (24, 28672) FP32 — fused projection
base: (24,) — [pre(4), post(4), res(16)]
scale: (3,) — [alpha_pre, alpha_post, alpha_res]
"""
n = self.n_hc
dev = self.device
# fn rows: [W_pre(4), W_res(16), W_post(4)] — matches _dynamic_params
# A_raw = proj[:, 0:4] ← W_pre
# B_raw = proj[:, 4:20] ← W_res
# C_raw = proj[:, 20:24] ← W_post
W_pre = fn[0:n].to(device=dev, dtype=torch.float32).contiguous() # fn[0:4]
W_res = fn[n:n+n*n].to(device=dev, dtype=torch.float32).contiguous() # fn[4:20]
W_post = fn[n+n*n:].to(device=dev, dtype=torch.float32).contiguous() # fn[20:24]
# base: [S_pre(4), S_res(16), S_post(4)] — matches fn ordering [A, B, C]
# The checkpoint stores all 3 arrays (fn, base, scale) in the same
# [pre, res, post] order matching _dynamic_params' A/B/C split.
# Previous note "[pre, post, res]" was incorrect for base/scale.
S_pre = base[0:n].reshape(1, n).to(device=dev, dtype=torch.bfloat16).contiguous()
S_res = base[n:n+n*n].reshape(n, n).to(device=dev, dtype=torch.bfloat16).contiguous() # base[4:20]
S_post = base[n+n*n:].reshape(n, 1).to(device=dev, dtype=torch.bfloat16).contiguous() # base[20:24]
# scale: [alpha_pre, alpha_res, alpha_post] — matches [A, B, C] ordering
alpha_pre = scale[0].item()
alpha_res = scale[1].item()
alpha_post = scale[2].item()
self._impl.load_weights(
W_pre=W_pre, W_res=W_res, W_post=W_post,
S_pre=S_pre, S_res=S_res, S_post=S_post,
alpha_pre=alpha_pre, alpha_res=alpha_res, alpha_post=alpha_post)
@staticmethod
def init_state(embeddings, n_hc=4):
from dsv4.layers.mhc import mHCLayer
return mHCLayer.init_state(embeddings, n_hc)
def pre_block(self, X_l):
return self._impl.pre_block(X_l)
def post_block(self, X_l, F_out, ctx):
return self._impl.post_block(X_l, F_out, ctx)
# =====================================================================
# RoPE — partial, GPT-J interleaved, last rope_dim dims
# =====================================================================
def build_rope_cache(max_pos, rope_dim, device, theta=10000.0):
"""Build cos/sin caches for partial RoPE.
CRITICAL: FP32, not BF16! BF16 quantization destroys cos²+sin²=1
identity needed for inverse RoPE. BF16 cos²+sin² can be 0.996,
causing ~3% round-trip error that accumulates across 61 layers.
Returns: (cos_cache, sin_cache) each (max_pos, rope_dim//2) FP32
"""
half = rope_dim // 2
freqs = 1.0 / (theta ** (torch.arange(0, rope_dim, 2, dtype=torch.float32) / rope_dim))
angles = torch.outer(torch.arange(max_pos, dtype=torch.float32), freqs)
return torch.cos(angles).to(device), torch.sin(angles).to(device)
def apply_rope_partial(x, positions, cos_cache, sin_cache, head_dim, rope_dim):
"""Apply partial GPT-J interleaved RoPE to the last rope_dim dims of each head.
Computes in FP32 for numerical stability (inverse RoPE requires cos²+sin²=1)."""
T, n_h, hd = x.shape
nope = hd - rope_dim
cos = cos_cache[positions].unsqueeze(1) # (T, 1, half) FP32
sin = sin_cache[positions].unsqueeze(1)
x_rope = x[:, :, nope:].float() # FP32 for accurate rotation
x_even = x_rope[..., 0::2]
x_odd = x_rope[..., 1::2]
rot_even = x_even * cos - x_odd * sin
rot_odd = x_even * sin + x_odd * cos
result = x.clone()
rope_out = torch.empty_like(x_rope)
rope_out[..., 0::2] = rot_even
rope_out[..., 1::2] = rot_odd
result[:, :, nope:] = rope_out.to(torch.bfloat16)
return result
def apply_inverse_rope(o, positions, cos_cache, sin_cache, head_dim, rope_dim):
"""Apply inverse RoPE (conjugate rotation) to attention output.
Computes in FP32 for numerical stability."""
T, n_h, hd = o.shape
nope = hd - rope_dim
cos = cos_cache[positions].unsqueeze(1)
sin = sin_cache[positions].unsqueeze(1)
o_rope = o[:, :, nope:].float()
o_even = o_rope[..., 0::2]
o_odd = o_rope[..., 1::2]
inv_even = o_even * cos + o_odd * sin
inv_odd = -o_even * sin + o_odd * cos
result = o.clone()
rope_out = torch.empty_like(o_rope)
rope_out[..., 0::2] = inv_even
rope_out[..., 1::2] = inv_odd
result[:, :, nope:] = rope_out.to(torch.bfloat16)
return result
class SimpleKVCache:
"""Per-layer KV cache for decode. Stores BF16 K,V accumulated across steps.
MQA: 1 KV head, so cache is (1, seq_len, hd) per layer."""
def __init__(self, head_dim, max_seq=8192, device='cuda:0'):
self.hd = head_dim
self.max_seq = max_seq
self.device = device
self.k = torch.zeros(1, max_seq, head_dim, dtype=torch.bfloat16, device=device)
self.v = torch.zeros(1, max_seq, head_dim, dtype=torch.bfloat16, device=device)
self.len = 0
def append(self, k_new, v_new):
"""Append K,V. k_new: (1, T, hd), v_new: (1, T, hd)."""
T = k_new.shape[1]
self.k[0, self.len:self.len + T] = k_new[0]
self.v[0, self.len:self.len + T] = v_new[0]
self.len += T
def get(self):
"""Get K,V up to current length. Returns (1, seq_len, hd) each."""
return self.k[:, :self.len], self.v[:, :self.len]
# =====================================================================
# Weight loading — streams safetensors shards, distributes to 8 GPUs
# =====================================================================
def load_weights_to_cpu(checkpoint_dir):
"""Load all weights from checkpoint to CPU memory.
Weights stay on CPU; we move per-layer to GPU on demand during inference.
This avoids OOM from 285K GPU allocations and allows streaming.
Returns:
all_weights: dict[key] → tensor on CPU
"""
from safetensors.torch import load_file
cdir = Path(checkpoint_dir)
index_path = cdir / "model.safetensors.index.json"
weight_map = {}
if index_path.exists():
with open(index_path) as f:
weight_map = json.load(f).get("weight_map", {})
shard_names = set(weight_map.values()) if weight_map else {
f"model-{i:05d}-of-00095.safetensors" for i in range(1, 96)
}
print(f"Loading {len(shard_names)} shards to CPU...")
all_weights = {}
loaded = 0
for shard_name in sorted(shard_names):
if not (cdir / shard_name).exists():
continue
data = load_file(str(cdir / shard_name))
all_weights.update(data)
loaded += 1
if loaded % 20 == 0:
print(f" {loaded}/{len(shard_names)} shards, {len(all_weights)} tensors")
print(f" Done: {len(all_weights)} tensors on CPU")
return all_weights
def get_layer_weights(all_weights, li, device):
"""Get weights for layer li, moved to target device.
Returns dict of key→tensor on device. Filters by model.layers.{li} prefix.
"""
prefix = f"model.layers.{li}."
w = {}
for key in all_weights:
if key.startswith(prefix):
w[key] = all_weights[key].to(device=device, non_blocking=True)
return w
def cache_all_layer_weights(all_weights, n_layers, devices):
"""Pre-load ALL layer weights to their target GPUs.
This avoids the per-token CPU→GPU transfer bottleneck. Each layer's
weights stay on its target GPU for the entire inference run.
"""
print(f" Caching layer weights to GPUs...")
cached = {}
for li in range(n_layers):
gpu = li % len(devices)
dev = devices[gpu]
cached[li] = get_layer_weights(all_weights, li, dev)
if (li + 1) % 10 == 0:
print(f" {li+1}/{n_layers} layers cached")
print(f" All {n_layers} layers cached to GPUs")
return cached
# =====================================================================
# Single layer forward
# =====================================================================
def forward_layer(X_l, w, li, cfg, rope_cos, rope_sin,
attn_mhc, ffn_mhc, attn_norm, ffn_norm,
kv_cache, token_id, positions):
"""Forward one layer with mHC + Attention + FFN.
Architecture (paper §2):
X_l → mHC.pre_block(attn) → RMSNorm → Attention → F_attn → mHC.post_block → X_mid
X_mid → mHC.pre_block(ffn) → RMSNorm → MoE → F_ffn → mHC.post_block → X_{l+1}
X_l: (T, n_hc, H) BF16 — mHC residual state
Returns: X_next (T, n_hc, H) BF16
"""
device = X_l.device
H = cfg["hidden_size"]
n_h = cfg["num_attention_heads"]
hd = cfg["head_dim"]
rd = cfg.get("qk_rope_head_dim", cfg.get("rope_dim", 64))
o_rank = cfg.get("output_group_dim", 1024)
o_groups = cfg.get("num_output_groups", 16)
n_hc = 4
pre = f"model.layers.{li}.self_attn"
T = X_l.shape[0]
heads_per_group = n_h // o_groups
group_input_dim = heads_per_group * hd
# ==================================================================
# ATTENTION SUB-BLOCK
# ==================================================================
# -- mHC pre_block (attention) --
x_in, attn_ctx = attn_mhc.pre_block(X_l) # x_in: (T, H)
if MHC_DIAG: # mHC diagnostics
A_l = None
B_l, C_l = attn_ctx
print(f" L{li} pre_attn: |X_l|={X_l.abs().max().item():.2f} |x_in|={x_in.abs().max().item():.2f}", flush=True)
# -- RMSNorm (pre-norm before attention) --
x_normed = attn_norm.forward(x_in) # (T, H) BF16
# -- Q projection: q_a (low-rank down) → q_a_norm → q_b (low-rank up) --
c_Q = nvfp4_linear(x_normed,
w[f"{pre}.q_a_proj.weight"],
w[f"{pre}.q_a_proj.weight_scale"],
w[f"{pre}.q_a_proj.weight_scale_2"]) # (T, dc)
# Q norm (RMSNorm after q_a, before q_b)
q_norm_w = w.get(f"{pre}.q_a_norm.weight")
if q_norm_w is not None:
c_Q_f = c_Q.float()
c_Q_rms = c_Q_f.pow(2).mean(-1, keepdim=True).add(1e-6).rsqrt()
c_Q = (c_Q_f * c_Q_rms * q_norm_w.float()).bfloat16()
q = nvfp4_linear(c_Q,
w[f"{pre}.q_b_proj.weight"],
w[f"{pre}.q_b_proj.weight_scale"],
w[f"{pre}.q_b_proj.weight_scale_2"]) # (T, n_h * hd)
# -- KV projection (MQA: 1 KV head) + KV norm --
kv = nvfp4_linear(x_normed,
w[f"{pre}.kv_proj.weight"],
w[f"{pre}.kv_proj.weight_scale"],
w[f"{pre}.kv_proj.weight_scale_2"]) # (T, hd)
# KV norm (RMSNorm after kv_proj)
kv_norm_w = w.get(f"{pre}.kv_norm.weight")
if kv_norm_w is not None:
kv_f = kv.float()
kv_rms = kv_f.pow(2).mean(-1, keepdim=True).add(1e-6).rsqrt()
kv = (kv_f * kv_rms * kv_norm_w.float()).bfloat16()
# -- Reshape for attention --
q_heads = q.reshape(T, n_h, hd) # (T, n_h, hd)
kv_new = kv.reshape(T, 1, hd) # (T, 1, hd) — 1 KV head
# -- Apply RoPE to Q (at current positions) --
positions_dev = positions.to(device)
q_heads = apply_rope_partial(q_heads, positions_dev, rope_cos, rope_sin, hd, rd)
# -- Apply RoPE to KV (at current positions) BEFORE caching --
# DSV4 convention: RoPE applied to KV before writing to cache.
# K = V in DSV4 MQA (same projection, same RoPE'd tensor).
kv_new = apply_rope_partial(kv_new, positions_dev, rope_cos, rope_sin, hd, rd)
# -- KV cache: append RoPE'd KV (K=V) --
k_new = kv_new # (T, 1, hd) — RoPE'd
v_new = kv_new # K = V in DSV4 MQA
kv_cache.append(k_new.permute(1, 0, 2), v_new.permute(1, 0, 2)) # (1, T, hd)
# -- Get full KV from cache (already RoPE'd) --
k_full, v_full = kv_cache.get() # (1, seq_len, hd) each — RoPE'd, K=V
seq_len = k_full.shape[1]
# -- Attention: SDPA for short seqs (avoids FMHA padding bug), FMHA for long --
q_input = q_heads.permute(1, 0, 2) # (n_h, T, hd)
scale = 1.0 / math.sqrt(hd)
# FMHA pads N to next multiple of 128. For N<<128, padded zero-K entries
# contribute exp(0)=1 to softmax, diluting real attention weights by ~128/N.
# Use SDPA for short sequences where padding dominates.
if seq_len < 120:
k_expanded = k_full.expand(n_h, -1, -1).contiguous()
v_expanded = v_full.expand(n_h, -1, -1).contiguous()
# Attention sink (paper D5c)
sink_key = f"{pre}.sinks"
if sink_key in w and seq_len > 0:
sinks = w[sink_key].to(device=device) # (n_h,) BF16
sink_k = torch.zeros(n_h, 1, hd, dtype=torch.bfloat16, device=device)
sink_v = torch.zeros(n_h, 1, hd, dtype=torch.bfloat16, device=device)
k_with_sink = torch.cat([k_expanded, sink_k], dim=1)
v_with_sink = torch.cat([v_expanded, sink_v], dim=1)
sink_bias_mask = torch.zeros(n_h, T, seq_len + 1, dtype=torch.bfloat16, device=device)
for h in range(n_h):
sink_bias_mask[h, :, -1] = sinks[h]
attn_out = torch.nn.functional.scaled_dot_product_attention(
q_input, k_with_sink, v_with_sink,
attn_mask=sink_bias_mask, scale=scale)
else:
attn_out = torch.nn.functional.scaled_dot_product_attention(
q_input, k_expanded, v_expanded, scale=scale, is_causal=False)
attn_out = attn_out.permute(1, 0, 2) # (T, n_h, hd)
else:
# Use FMHA kernel for longer sequences (padding effect is negligible)
from dsv4.kernels.attention.fmha_multitile_op import fmha_multitile_decode_raw
q_4d = q_input.unsqueeze(0).contiguous()
k_4d = k_full.unsqueeze(0).contiguous()
v_4d = v_full.unsqueeze(0).transpose(-1, -2).contiguous()
o_4d, lse = fmha_multitile_decode_raw(q_4d, k_4d, v_4d, scale)
attn_out = o_4d.squeeze(0).permute(1, 0, 2)
# Sink correction
sink_key = f"{pre}.sinks"
if sink_key in w and seq_len > 0:
sinks = w[sink_key].to(device=device)
lse_2d = lse.squeeze(0).t()
sink_exp = torch.exp(sinks.float())
attn_exp = torch.exp(lse_2d.float())
correction = attn_exp / (attn_exp + sink_exp.unsqueeze(0) + 1e-10)
attn_out = (attn_out.float() * correction.unsqueeze(-1)).bfloat16()
attn_out = attn_out.bfloat16()
# -- Inverse RoPE on attention output (paper §2.3.3) --
# DSV4 uses K=V in MQA; both get RoPE'd. Inverse RoPE on the output
# at query position q converts: R(q)⁻¹ Σ softmax(R(q)Q·R(p)K) R(p)V
# For single KV entry at p: R(p-q)V (relative position encoding)
# This only affects the last 64 dims (partial RoPE); first 448 unchanged.
# The relative encoding in those 64 dims may be INTENTIONAL — the
# output projection can use it for position-dependent computation.
# Test both modes via INVERSE_ROPE flag.
if INVERSE_ROPE:
attn_out = apply_inverse_rope(attn_out, positions_dev, rope_cos, rope_sin, hd, rd)
# -- Output projection: wo_a (grouped BMM) + wo_b (NVFP4) --
# wo_a: grouped linear, (n_h, hd) → (n_groups, o_rank) via BMM
attn_flat = attn_out.reshape(T, n_h * hd) # (T, n_h * hd)
attn_grouped = attn_flat.reshape(T, o_groups, heads_per_group * hd) # (T, groups, group_dim)
oa_w = w[f"{pre}.o_a_proj.weight"].bfloat16() # (n_groups * o_rank, group_input_dim) BF16
oa_3d = oa_w.reshape(o_groups, o_rank, group_input_dim) # (groups, o_rank, group_dim)
attn_for_bmm = attn_grouped.permute(1, 0, 2) # (groups, T, group_dim)
grouped_out = torch.bmm(attn_for_bmm, oa_3d.transpose(1, 2)) # (groups, T, o_rank)
grouped_flat = grouped_out.permute(1, 0, 2).reshape(T, o_groups * o_rank) # (T, groups*o_rank)
F_attn = nvfp4_linear(grouped_flat,
w[f"{pre}.o_b_proj.weight"],
w[f"{pre}.o_b_proj.weight_scale"],
w[f"{pre}.o_b_proj.weight_scale_2"]) # (T, H)
# -- mHC post_block (attention) --
X_mid = attn_mhc.post_block(X_l, F_attn, attn_ctx) # (T, n_hc, H)
# Diagnostic: check mHC is stabilizing the residual
if MHC_DIAG: # mHC diagnostics
B_l, C_l = attn_ctx
print(f" L{li} attn: |X_l|={X_l.abs().max().item():.2f} |F_attn|={F_attn.abs().max().item():.2f} |B|={B_l.abs().max().item():.4f} |C|={C_l.abs().max().item():.4f} |X_mid|={X_mid.abs().max().item():.2f}")
# Check B_l is doubly stochastic (rows sum to 1.0)
B_row_sums = B_l.sum(dim=-1) # (T, n_hc)
B_col_sums = B_l.sum(dim=-2) # (T, n_hc)
print(f" B row_sums={B_row_sums[0].tolist()} col_sums={B_col_sums[0].tolist()}")
print(f" C_l={C_l[0].tolist()}")
# ==================================================================
# FFN SUB-BLOCK
# ==================================================================
# -- mHC pre_block (FFN) --
x_ffn, ffn_ctx = ffn_mhc.pre_block(X_mid) # (T, H)
# -- RMSNorm (pre-norm before FFN) --
x_ffn_normed = ffn_norm.forward(x_ffn) # (T, H) BF16
# -- MoE + shared expert --
F_ffn = moe_forward(x_ffn_normed, w, li, cfg, token_id, device)
# -- mHC post_block (FFN) --
X_next = ffn_mhc.post_block(X_mid, F_ffn, ffn_ctx) # (T, n_hc, H)
if MHC_DIAG: # ffn mHC diagnostics
B_l_ffn, C_l_ffn = ffn_ctx
print(f" L{li} ffn: |X_mid|={X_mid.abs().max().item():.2f} |F_ffn|={F_ffn.abs().max().item():.2f} |B|={B_l_ffn.abs().max().item():.4f} |C|={C_l_ffn.abs().max().item():.4f} |X_next|={X_next.abs().max().item():.2f}", flush=True)
return X_next
# =====================================================================
# MoE forward — hash + dense routing, SwiGLU with clamping
# =====================================================================
def moe_forward(x, w, li, cfg, token_id, device):
"""Run routed MoE + shared expert.
x: (T, H) BF16 — post-RMSNorm FFN input
Returns: (T, H) BF16
"""
H = cfg["hidden_size"]
n_experts = cfg["n_routed_experts"]
top_k = cfg.get("num_experts_per_tok", 6)
routed_scaling = cfg.get("routed_scaling_factor", 2.5)
swiglu_limit = cfg.get("swiglu_limit", 10.0)
mlp_inter = cfg["moe_intermediate_size"]
is_hash = li < 3
# ---- Routing ----
expert_ids = None
expert_weights = None
if is_hash:
tid2eid_key = f"model.layers.{li}.mlp.gate.tid2eid"
if tid2eid_key in w:
tid2eid = w[tid2eid_key]
tid = token_id.item() if token_id.numel() == 1 else token_id[0].item()
expert_ids = tid2eid[tid] # (top_k,) int64
expert_weights = torch.ones(top_k, dtype=torch.float32, device=x.device) / top_k
else:
# Fallback: use dense routing even for hash layers
is_hash = False
if not is_hash:
# Dense routing: sqrt(softplus(X @ W_gate)) + e_bias for selection
gate_w = w[f"model.layers.{li}.mlp.gate.weight"] # (H, n_experts) BF16
logits = torch.nn.functional.linear(x, gate_w.bfloat16()) # (T, n_experts)
# Activation: sqrt(softplus(logits))
activated = torch.sqrt(torch.nn.functional.softplus(logits.float()) + 1e-6)
# e_bias: learned per-expert bias for SELECTION ONLY (not in weights)
e_bias_key = f"model.layers.{li}.mlp.gate.e_bias"
if e_bias_key in w:
activated = activated + w[e_bias_key].float().unsqueeze(0)
# Top-k
scores, indices = activated.topk(top_k, dim=-1) # (T, top_k)
# Renormalize on UNBIASED activation (no e_bias in weights)
unbiased = torch.sqrt(torch.nn.functional.softplus(logits.float()) + 1e-6)
unbiased_scores = torch.gather(unbiased, -1, indices)
expert_weights = unbiased_scores / unbiased_scores.sum(dim=-1, keepdim=True)
# For T=1 decode, squeeze
if x.shape[0] == 1:
expert_ids = indices[0]
expert_weights = expert_weights[0]
else:
raise NotImplementedError("Multi-token MoE routing")
# ---- Run selected experts ----
T = x.shape[0]
expert_outputs = []
if not SKIP_ROUTED_MOE:
for i, eid in enumerate(expert_ids):
eid_int = eid.item()
epre = f"model.layers.{li}.mlp.experts.{eid_int}"
gate = nvfp4_linear(x,
w[f"{epre}.gate_proj.weight"],
w[f"{epre}.gate_proj.weight_scale"],
w[f"{epre}.gate_proj.weight_scale_2"])
up = nvfp4_linear(x,
w[f"{epre}.up_proj.weight"],
w[f"{epre}.up_proj.weight_scale"],
w[f"{epre}.up_proj.weight_scale_2"])
# SwiGLU with clamping (paper §4.2.3)
silu_out = torch.nn.functional.silu(gate.float())
if swiglu_limit is not None:
silu_out = silu_out.clamp(-swiglu_limit, swiglu_limit)
up_clamped = up.float().clamp(-swiglu_limit, swiglu_limit)
else:
up_clamped = up.float()
hidden = (silu_out * up_clamped).bfloat16()
down = nvfp4_linear(hidden,
w[f"{epre}.down_proj.weight"],
w[f"{epre}.down_proj.weight_scale"],
w[f"{epre}.down_proj.weight_scale_2"])
expert_outputs.append(down)
# Weighted combine + scaling
routed_out = torch.zeros_like(x)
for i, (out, wt) in enumerate(zip(expert_outputs, expert_weights)):
routed_out = routed_out + (out.float() * wt.item()).bfloat16()
routed_out = (routed_out.float() * routed_scaling).bfloat16()
# ---- Shared expert ----
se_pre = f"model.layers.{li}.mlp.shared_experts"
se_gate_key = f"{se_pre}.gate_proj.weight"
if se_gate_key in w:
gate = nvfp4_linear(x,
w[se_gate_key],
w[f"{se_pre}.gate_proj.weight_scale"],
w[f"{se_pre}.gate_proj.weight_scale_2"])
up = nvfp4_linear(x,
w[f"{se_pre}.up_proj.weight"],
w[f"{se_pre}.up_proj.weight_scale"],
w[f"{se_pre}.up_proj.weight_scale_2"])
silu_out = torch.nn.functional.silu(gate.float())
if swiglu_limit is not None:
silu_out = silu_out.clamp(-swiglu_limit, swiglu_limit)
up_clamped = up.float().clamp(-swiglu_limit, swiglu_limit)
else:
up_clamped = up.float()
hidden = (silu_out * up_clamped).bfloat16()
shared_out = nvfp4_linear(hidden,
w[f"{se_pre}.down_proj.weight"],
w[f"{se_pre}.down_proj.weight_scale"],
w[f"{se_pre}.down_proj.weight_scale_2"])
else:
shared_out = torch.zeros_like(x)
return routed_out + shared_out
# =====================================================================
# Main
# =====================================================================
def main():
t_start = time.time()
print("=" * 70)
print("DSV4 Single-Shot Inference — Full Pipeline (mHC+Attn+MoE)")
print(" Proper Sinkhorn mHC, RMSNorm, inverse RoPE, production FMHA")
print("=" * 70)
with open(os.path.join(CHECKPOINT_DIR, "config.json")) as f:
cfg = json.load(f)
n_layers = cfg["num_hidden_layers"]
H = cfg["hidden_size"]
n_h = cfg["num_attention_heads"]
hd = cfg["head_dim"]
rd = cfg.get("qk_rope_head_dim", cfg.get("rope_dim", 64))
n_hc = 4
print(f"Model: {n_layers} layers, {n_h} heads, hd={hd}, rope_dim={rd}")
print(f"Experts: {cfg['n_routed_experts']}, top-{cfg.get('num_experts_per_tok', 6)}")
# ==== Phase 1: Load weights to CPU ====
print(f"\n{'='*70}\nPhase 1: Loading weights to CPU\n{'='*70}")
all_weights = load_weights_to_cpu(CHECKPOINT_DIR)
t_loaded = time.time()
print(f"Weight loading: {t_loaded - t_start:.1f}s")
# ==== Build mHC blocks + RMSNorms (small weights, keep on GPU) ====
print("Building mHC blocks and RMSNorms...")
attn_mhc_blocks = {}
ffn_mhc_blocks = {}
attn_norms = {}
ffn_norms = {}
for li in range(n_layers):
gpu = li % NUM_GPUS
dev = f"cuda:{gpu}"
# mHC blocks (small weights: fn (24, 28672) FP32 ≈ 2.6MB each)
for prefix, blocks in [(f"model.layers.{li}.attn_hc", attn_mhc_blocks),
(f"model.layers.{li}.ffn_hc", ffn_mhc_blocks)]:
fn_key = f"{prefix}.fn"
base_key = f"{prefix}.base"
scale_key = f"{prefix}.scale"
if fn_key in all_weights and base_key in all_weights and scale_key in all_weights:
mhc = mHCBlock(hidden_dim=H, n_hc=n_hc, device=dev)
mhc.load_from_checkpoint(
all_weights[fn_key], all_weights[base_key], all_weights[scale_key])
blocks[li] = mhc
else:
print(f" WARNING: no mHC weights for {prefix}, using identity fallback")
mhc = mHCBlock(hidden_dim=H, n_hc=n_hc, device=dev)
n = n_hc
K = n * H
mhc.W_stacked = torch.zeros(n + n*n + n, K, dtype=torch.float32, device=dev)
mhc.S_pre = torch.zeros(1, n, dtype=torch.float32, device=dev)
mhc.S_res = torch.eye(n, dtype=torch.float32, device=dev)
mhc.S_post = torch.ones(n, 1, dtype=torch.float32, device=dev) * 0.5
mhc.alpha_pre = 0.01
mhc.alpha_res = 0.01
mhc.alpha_post = 0.01
blocks[li] = mhc
# RMSNorms
attn_norm = RMSNorm(H, eps=cfg.get('rms_norm_eps', 1e-6), device=dev)
an_key = f"model.layers.{li}.input_layernorm.weight"
if an_key in all_weights:
attn_norm.weight = all_weights[an_key].to(device=dev, dtype=torch.float32)
attn_norms[li] = attn_norm
ffn_norm = RMSNorm(H, eps=cfg.get('rms_norm_eps', 1e-6), device=dev)
fn_key = f"model.layers.{li}.post_attention_layernorm.weight"
if fn_key in all_weights:
ffn_norm.weight = all_weights[fn_key].to(device=dev, dtype=torch.float32)
ffn_norms[li] = ffn_norm
print(f" attn mHC: {len(attn_mhc_blocks)}, ffn mHC: {len(ffn_mhc_blocks)}")
# ==== Global weights (small, keep on gpu0) ====
torch.cuda.set_device(0)
embed_w = all_weights.get("model.embed_tokens.weight")
embed = torch.nn.Embedding.from_pretrained(embed_w.bfloat16().to('cuda:0'))
lm_w = all_weights.get("lm_head.weight", embed_w).bfloat16().to('cuda:0')
final_norm_w = all_weights.get("model.norm.weight")
if final_norm_w is not None:
final_norm_w = final_norm_w.to('cuda:0')
rope_caches = {g: build_rope_cache(8192, rd, f"cuda:{g}") for g in range(NUM_GPUS)}
# ==== KV caches (one per layer on its GPU) ====
kv_caches = {}
for li in range(n_layers):
kv_caches[li] = SimpleKVCache(head_dim=hd, max_seq=8192, device=f"cuda:{li % NUM_GPUS}")
# ==== Cache ALL layer weights to GPUs (avoids per-token CPU→GPU transfer) ====
print(f"\n Caching layer weights to GPUs (one-time transfer)...", flush=True)
devices = [f"cuda:{g}" for g in range(NUM_GPUS)]
layer_weights = cache_all_layer_weights(all_weights, n_layers, devices)
print(f" Done. Freeing CPU weights...", flush=True)
del all_weights
import gc; gc.collect()
# ==== Phase 2: Compile FMHA ====
print(f"\n{'='*70}\nPhase 2: JIT compiling\n{'='*70}")
from dsv4.kernels.attention.production import dsv4_attention
torch.cuda.set_device(0)
dummy_q = torch.randn(n_h, 1, hd, dtype=torch.bfloat16, device='cuda:0')
dummy_k = torch.randn(1, 1, hd, dtype=torch.bfloat16, device='cuda:0')
try:
_ = dsv4_attention(dummy_q, dummy_k, dummy_k.clone())
print(" FMHA: compiled OK")
except Exception as e:
print(f" FMHA error: {e}")
t_compiled = time.time()
print(f"Compile: {t_compiled - t_loaded:.1f}s")
# ==== Phase 2.5: Minimal E2E test ====
print(f"\n{'='*70}\nPhase 2.5: Minimal E2E Test (single token 'The')\n{'='*70}")
from transformers import AutoTokenizer
tokenizer = AutoTokenizer.from_pretrained(CHECKPOINT_DIR)
minimal_e2e_test(layer_weights, cfg, rope_caches, attn_mhc_blocks,
ffn_mhc_blocks, attn_norms, ffn_norms, embed, lm_w,
final_norm_w, tokenizer)
# ==== Phase 3: Inference ====
print(f"\n{'='*70}\nPhase 3: Inference\n{'='*70}")
# DeepSeek V4 chat format: <begin▁of▁sentence><User>prompt<Assistant>
# For reasoning models: <User>prompt<Assistant>fithinking...flanswer
# Special token IDs: <User>=128803, <Assistant>=128804, <|EOT|>=128805
# Thinking tokens: fi=128821, fl=128822
USER_TOKEN = 128803
ASSISTANT_TOKEN = 128804
EOT_TOKEN = 128805
THINK_START = 128821 # fi
THINK_END = 128822 # fl
# Build input with proper DeepSeek chat format
bos_id = tokenizer.bos_token_id or 0
# <BOS> <User> System prompt \n\n User prompt <Assistant>
input_ids_list = [bos_id, USER_TOKEN]
input_ids_list += tokenizer.encode(SYSTEM_PROMPT, add_special_tokens=False)
input_ids_list += tokenizer.encode('\n\n' + PROMPT, add_special_tokens=False)
input_ids_list.append(ASSISTANT_TOKEN)
input_ids = torch.tensor([input_ids_list], dtype=torch.long).cuda()
print(f"DeepSeek chat format. Input: {input_ids.shape[1]} tokens", flush=True)
print(f"Decoded start: '{tokenizer.decode(input_ids[0][:20])}...'", flush=True)
print(f"Decoded end: '...{tokenizer.decode(input_ids[0][-5:])}'", flush=True)
generated = input_ids[0].tolist()
# ==== Prefill: process prompt tokens to fill KV cache ====
print(f"Prefilling {len(generated)} prompt tokens...", flush=True)
for prefill_idx, tid_val in enumerate(generated):
t0 = time.time()
tid = torch.tensor([tid_val], dtype=torch.long, device='cuda:0')
positions = torch.tensor([prefill_idx], dtype=torch.long, device='cuda:0')
emb = embed(tid) # (1, H) on gpu0
X = mHCBlock.init_state(emb, n_hc) # (1, n_hc, H)
for li in range(n_layers):
gpu = li % NUM_GPUS
dev = f"cuda:{gpu}"
if X.device != torch.device(dev):
X = X.to(dev)
torch.cuda.set_device(gpu)
w = layer_weights[li]
attn_mhc = attn_mhc_blocks.get(li)
ffn_mhc = ffn_mhc_blocks.get(li)
a_norm = attn_norms[li]
f_norm = ffn_norms[li]
rc, rs = rope_caches[gpu]
X = forward_layer(X, w, li, cfg, rc, rs,
attn_mhc, ffn_mhc, a_norm, f_norm,
kv_caches[li], tid, positions)
X = X.to('cuda:0')
torch.cuda.set_device(0)
if prefill_idx % 10 == 0:
print(f" Token {prefill_idx}/{len(generated)}: {time.time()-t0:.2f}s", flush=True)
print(f" Prefill done ({len(generated)} tokens, {time.time()-t_compiled:.1f}s)")
# ==== Decode: generate new tokens ====
print(f"\nDecoding (max {MAX_NEW_TOKENS} new tokens)...")
all_tokens = generated.copy()
for step in range(MAX_NEW_TOKENS):
t0 = time.time()
tid = torch.tensor([all_tokens[-1]], dtype=torch.long, device='cuda:0')
decode_pos = len(all_tokens) - 1
positions = torch.tensor([decode_pos], dtype=torch.long, device='cuda:0')
emb = embed(tid) # (1, H) on gpu0
X = mHCBlock.init_state(emb, n_hc) # (1, n_hc, H)
for li in range(n_layers):
gpu = li % NUM_GPUS
dev = f"cuda:{gpu}"
if X.device != torch.device(dev):
X = X.to(dev)
torch.cuda.set_device(gpu)
w = layer_weights[li]
attn_mhc = attn_mhc_blocks.get(li)
ffn_mhc = ffn_mhc_blocks.get(li)
a_norm = attn_norms[li]
f_norm = ffn_norms[li]
rc, rs = rope_caches[gpu]
X = forward_layer(X, w, li, cfg, rc, rs,
attn_mhc, ffn_mhc, a_norm, f_norm,
kv_caches[li], tid, positions)
X = X.to('cuda:0')
torch.cuda.set_device(0)
# Read out stream 0 → RMSNorm → lm_head
x_out = X[:, 0, :] # (1, H)
if final_norm_w is not None:
xf = x_out.float()
rms = xf.pow(2).mean(-1, keepdim=True).add(1e-6).rsqrt()
x_out = (xf * rms * final_norm_w.float()).bfloat16()
logits = torch.nn.functional.linear(x_out, lm_w)
# Top-5 predictions for debugging
# Top-20 predictions for debugging (includes thinking tokens)
top20_vals, top20_ids = torch.topk(logits[0], 20)
top5_str = ' '.join([f'{tokenizer.decode([tid.item()])}({val.item():.1f})' for tid, val in zip(top5_ids[:5], top20_vals[:5])])
# Check if thinking tokens are in top-20
thinking_in_top20 = any(tid.item() in [128821, 128822] for tid in top20_ids)
top20_ids_set = set(top20_ids.tolist())
next_id = torch.argmax(logits, dim=-1).item()
generated.append(next_id)
all_tokens.append(next_id)
tok_str = tokenizer.decode([next_id])
dt = time.time() - t0
has_nan = torch.isnan(logits.float()).any().item()
has_inf = torch.isinf(logits.float()).any().item()
lmin, lmax = logits.float().min().item(), logits.float().max().item()
x_max = X.abs().max().item()
print(f" Step {step}: {next_id} '{tok_str}' ({dt:.2f}s) "
f"logits=[{lmin:.1f},{lmax:.1f}] nan={has_nan} inf={has_inf} "
f"|X|={x_max:.3f} top5: {top5_str}", flush=True)
if thinking_in_top20:
for tid_t, val_t in zip(top20_ids, top20_vals):
if tid_t.item() in [128821, 128822]:
print(f" THINK TOKEN: {tid_t.item()} logit={val_t.item():.3f}", flush=True)
if step % 5 == 0:
print(f" Top-20: {[(tokenizer.decode([t.item()]), f'{v.item():.2f}') for t, v in zip(top20_ids, top20_vals)]}", flush=True)
if has_nan or has_inf:
print(" Numerical issue — stopping")
break
if next_id == tokenizer.eos_token_id:
break
out = tokenizer.decode(generated, skip_special_tokens=True)
total = time.time() - t_start
print(f"\n{'='*70}")
print(f"Input: '{PROMPT}'")
print(f"Output: '{out}'")
print(f"Total: {total:.1f}s")
print(f"{'='*70}")
# =====================================================================
# Minimal end-to-end test — single token "The" through the model
# =====================================================================
def minimal_e2e_test(layer_weights, cfg, rope_caches, attn_mhc_blocks,
ffn_mhc_blocks, attn_norms, ffn_norms, embed, lm_w,
final_norm_w, tokenizer):
"""Process a single token 'The' through the model and check output logits.
This is a focused diagnostic: if the model can't even produce reasonable
logits for a single token, something is fundamentally wrong in the
pipeline. We check:
1. No NaN/Inf in any layer output
2. Residual stream magnitude stays bounded
3. Top-5 logits are sensible (not all Chinese tokens for English)
4. Logit spread (max - min) is > 1.0 (not uniform)
"""
n_layers = cfg["num_hidden_layers"]
H = cfg["hidden_size"]
n_h = cfg["num_attention_heads"]
hd = cfg["head_dim"]
rd = cfg.get("qk_rope_head_dim", cfg.get("rope_dim", 64))
n_hc = 4
# Tokenize just "The"
tid = torch.tensor(tokenizer.encode("The"), dtype=torch.long, device='cuda:0')
if tid.numel() > 1:
# If tokenizer adds BOS, take last token
print(f" Note: 'The' tokenized to {tid.numel()} tokens, using last one")
tid = tid[-1:]
print(f" Token ID: {tid.item()} = '{tokenizer.decode(tid.tolist())}'")
# Setup
positions = torch.tensor([0], dtype=torch.long, device='cuda:0')
emb = embed(tid) # (1, H)
X = mHCBlock.init_state(emb, n_hc) # (1, n_hc, H)
# Track per-layer diagnostics
layer_diags = []
for li in range(n_layers):
gpu = li % NUM_GPUS
dev = f"cuda:{gpu}"
if X.device != torch.device(dev):
X = X.to(dev)
torch.cuda.set_device(gpu)
w = layer_weights[li]
attn_mhc = attn_mhc_blocks.get(li)
ffn_mhc = ffn_mhc_blocks.get(li)
a_norm = attn_norms[li]
f_norm = ffn_norms[li]
rc, rs = rope_caches[gpu]
kv_cache = SimpleKVCache(head_dim=hd, max_seq=8192, device=dev)
X = forward_layer(X, w, li, cfg, rc, rs,
attn_mhc, ffn_mhc, a_norm, f_norm,
kv_cache, tid, positions)
# Per-layer diagnostic
x_max = X.abs().max().item()
has_nan = torch.isnan(X.float()).any().item()
has_inf = torch.isinf(X.float()).any().item()
# Stream 0 (primary)
x0 = X[:, 0, :]
x0_mean = x0.float().abs().mean().item()
x0_std = x0.float().std().item()
layer_diags.append({
'layer': li, 'gpu': gpu, 'x_max': x_max,
'x0_mean': x0_mean, 'x0_std': x0_std,
'nan': has_nan, 'inf': has_inf
})
if has_nan or has_inf:
print(f" ❌ Layer {li}: NaN={has_nan} Inf={has_inf} — STOPPING")
break
X = X.to('cuda:0')
torch.cuda.set_device(0)
# Final norm + lm_head
x_out = X[:, 0, :]
if final_norm_w is not None:
xf = x_out.float()
rms = xf.pow(2).mean(-1, keepdim=True).add(1e-6).rsqrt()
x_out = (xf * rms * final_norm_w.float()).bfloat16()
logits = torch.nn.functional.linear(x_out, lm_w)
# Results
print(f"\n === Minimal E2E Test Results ===")
print(f" Logits: min={logits.float().min().item():.2f} max={logits.float().max().item():.2f} "
f"spread={logits.float().max().item() - logits.float().min().item():.2f}")
print(f" NaN={torch.isnan(logits.float()).any().item()} "
f"Inf={torch.isinf(logits.float()).any().item()}")
top10_vals, top10_ids = torch.topk(logits[0], 10)
print(f" Top-10 predictions:")
for i, (tid_v, val) in enumerate(zip(top10_ids, top10_vals)):
tok_str = tokenizer.decode([tid_v.item()])
print(f" {i+1}. '{tok_str}' (id={tid_v.item()}, logit={val.item():.3f})")
# Print residual stream evolution
print(f"\n Residual stream evolution (stream 0):")
for d in layer_diags[::5]: # Every 5th layer
print(f" L{d['layer']:2d}: |X|={d['x_max']:.1f} "
f"mean={d['x0_mean']:.1f} std={d['x0_std']:.1f} "
f"nan={d['nan']} inf={d['inf']}")
# Always print last
if layer_diags:
d = layer_diags[-1]
print(f" L{d['layer']:2d}: |X|={d['x_max']:.1f} "
f"mean={d['x0_mean']:.1f} std={d['x0_std']:.1f} "
f"nan={d['nan']} inf={d['inf']}")
# Check for reasonable output
spread = logits.float().max().item() - logits.float().min().item()
if spread < 1.0:
print(f" ⚠️ Logit spread {spread:.2f} is very low — model is essentially uniform")
else:
print(f" ✓ Logit spread {spread:.2f} looks reasonable")
return logits, layer_diags
if __name__ == "__main__":
main()