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[Qwen3-Next][Perf][Attention] Replace torch.zeros with torch.empty to reduce overhead #28182

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[Qwen3-Next][Perf][Attention] Replace torch.zeros with torch.empty to reduce overhead #28182

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de09b29
replace torch.zeros with torch.empty to reduce overhead
ZJY0516 Nov 6, 2025
c2e4b0a
remove kda opt
ZJY0516 Nov 6, 2025
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3 changes: 2 additions & 1 deletion vllm/model_executor/models/qwen3_next.py
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Original file line number Diff line number Diff line change
Expand Up @@ -462,7 +462,7 @@ def forward(
# ============================================================
# Part 2: Core Attention (Custom Op)
# ============================================================
core_attn_out = torch.zeros(
core_attn_out = torch.empty(
(num_tokens, self.num_v_heads // self.tp_size, self.head_v_dim),
dtype=hidden_states.dtype,
device=hidden_states.device,
Expand Down Expand Up @@ -503,6 +503,7 @@ def _forward_core(

if attn_metadata is None:
# V1 profile run
core_attn_out.fill_(0)
return

assert isinstance(attn_metadata, dict)
Expand Down