chunked prefill support and memory opts

This commit is contained in:
2026-06-05 16:03:34 +08:00
parent 8c047a70ea
commit 2d1ef50992
4 changed files with 166 additions and 86 deletions

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@@ -9,20 +9,21 @@
# - DO NOT install BI-V150 corex Triton 2.1.0 (pkgs/triton): that causes
# GPU hang on BI-V100 because the Triton CUDA PTX kernels are incompatible.
#
# Chunked prefill note:
# --enable-chunked-prefill is NOT supported by the vendor's vllm 0.6.3 for
# has_inner_state=True models on BI-V100. It causes "Engine loop has died"
# immediately on first request. Do NOT use that flag.
# Long-context memory is instead handled by query-chunking inside
# _forward_prefix_pytorch (see paged_attn.py, _ATTN_Q_CHUNK=256).
# Important Note: Qwen3.6-27B must apply TP=4,PP=2 combination in order to deploy using 8 GPUs
#
# Recommended server start command:
# python3 -m vllm.entrypoints.openai.api_server \
# --model /workspace/models/Qwen3.6-27B --port 1111 \
# --served-model-name llm --max-model-len 20000 \
# --enforce-eager --trust-remote-code -tp 4 \
# --gpu-memory-utilization 0.95
# (No --enable-chunked-prefill, no --max-num-batched-tokens)
# Recommended server start command for TP=4, context length: 50K, no chunked prefill mechanism:
# CUDA_VISIBLE_DEVICES="4,5,6,7" VLLM_ENGINE_ITERATION_TIMEOUT_S=3600 python3 -m vllm.entrypoints.openai.api_server \
# --model /workspace/models/Qwen3.6-27B --port 1111 --served-model-name llm \
# --max-model-len 50000 --enforce-eager --trust-remote-code -tp 4 --gpu-memory-utilization 0.90 \
# --max-num-seqs 1 --disable-log-requests --disable-frontend-multiprocessing \
# --max-num-batched-tokens 50000
# Recommended server start command for TP=4 support 100K, need chunked prefill
# CUDA_VISIBLE_DEVICES="4,5,6,7" VLLM_ENGINE_ITERATION_TIMEOUT_S=3600 python3 -m vllm.entrypoints.openai.api_server \
# --model /workspace/models/Qwen3.6-27B --port 1111 --served-model-name llm \
# --max-model-len 100000 --enforce-eager --trust-remote-code -tp 8 --gpu-memory-utilization 0.95 \
# --max-num-seqs 1 --disable-log-requests --disable-frontend-multiprocessing \
# --max-num-batched-tokens 4096 --enable-chunked-prefill
# --- paged_attn.py: replace forward_prefix with pure-PyTorch fallback -------
# The Triton context_attention_fwd kernel hangs BI-V100 GPUs permanently