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[Misc] Remove unnecessary fallback to prefill-decode attention #19138

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Merged
merged 1 commit into from
Jun 5, 2025
Merged

[Misc] Remove unnecessary fallback to prefill-decode attention #19138

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5 changes: 1 addition & 4 deletions vllm/v1/attention/backends/triton_attn.py
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Original file line number Diff line number Diff line change
Expand Up @@ -171,10 +171,7 @@ def forward(
# Whenever making a change in this method, please benchmark the
# performance to make sure it does not introduce any overhead.

num_queries_per_kv = query.shape[1] // key.shape[1]
num_q_is_pow2 = (num_queries_per_kv & (num_queries_per_kv - 1)) == 0
use_prefill_decode_attn = (self.force_prefill_decode_attn
or not num_q_is_pow2)
use_prefill_decode_attn = self.force_prefill_decode_attn
num_actual_tokens = attn_metadata.num_actual_tokens

if use_prefill_decode_attn:
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