da3aaa134a
model: pipeline-parallel Qwen3 (from_weights_pp + stage forward)
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Layer-wise split: each stage loads only its contiguous layer range
[s*L, (s+1)*L); stage 0 keeps embed_tokens, the last stage keeps
norm/lm_head (others get a 1x1 placeholder). Heads are NOT split
(PP is orthogonal to TP). Adds embed/head and forward_layers_prefill/
forward_layers_decode that take and return the [tokens, hidden] hidden
state; per-stage PagedKVCache is indexed by local layer id.
sampling: derive Clone on SamplingParams (carried in the PP command enum).
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com >
2026-05-29 18:45:47 +08:00
ee68d3565d
fix: comprehensive review + 14 bug fixes + Phase 12/14 overhaul
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Strict code review identified 30+ issues across correctness, performance,
and architecture. This commit addresses 14 of them with verified fixes,
restructures Phase 12 for honest continuous batching, and updates Phase 14
to target FA2 (RTX 5090 SM120 lacks TMEM required by FA4).
Bug fixes:
- FIX-01: Global cuBLAS handle (thread-local singleton, was per-call)
- FIX-02: Remove 19 unnecessary cudaDeviceSynchronize calls from kernels
- FIX-03: Qwen3 ChatML template (was plain text concatenation)
- FIX-04: EOS token from tokenizer (was hardcoded 151645)
- FIX-05: Storage tracks actual GPU device ordinal (was always Cuda(0))
- FIX-06: unsqueeze stride preserves contiguous layout
- FIX-08: CudaDeviceProp replaced with heap buffer (was UB-prone padding)
- FIX-09: Tokenizer byte_fallback to <0xNN> tokens (was panic)
Feature additions:
- FIX-10: SSE streaming (/v1/chat/completions, OpenAI-compatible)
- FIX-11: Correct usage statistics (prompt/completion/total tokens)
- FIX-13: Temperature / top-k / top-p sampling with SamplingParams
Performance improvements:
- FIX-07: Caching allocator wired up (thread-local pool, pooled flag)
- FIX-12: KV cache staging buffers (zero-alloc get_kv_len via borrow_raw)
- FIX-14: GPU strided copy kernel (eliminates contiguous() CPU round-trip)
Architecture:
- Phase 12 engine restructured: prefill/decode separation, honest TODO
for batched GPU forward (requires Flash Attention)
- Phase 14 updated: FA2 for SM120 (FA4 requires TMEM, absent on 5090)
- Qwen3-7B → Qwen3-8B typo fixed across all docs (36 layers, hidden 4096)
Validated on dash5 (8x RTX 5090):
- 52/52 API prompts pass (EN/CN/code), SSE streaming verified
- Logits match HF transformers 9/10 top-1, 4.0/5 avg top-5 overlap
- 8 concurrent requests: 5.99x scheduling speedup (batch_size=4)
- Throughput: 10.3 tok/s (serial), 30% of HF baseline
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com >
2026-05-22 17:53:28 +08:00
