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A high-throughput and memory-efficient inference and serving engine for LLMs

Mirrored from https://github.com/tduncan-lum/Nvidia-Optimization-Stack---VLLM.git

Synced Nov 14, 05:30 UTC

[Bugfix] Fixing division by zero in triton_attn if query_heads/kv_heads > 16 (#23424)

Signed-off-by: Burkhard Ringlein <ngl@zurich.ibm.com>

Burkhard Ringlein committed Sep 3, 2025 at 17:01 UTC 6d80ae83e1455cb0e47196cea557398fde0f03d1
1 file changed +2 -1
vllm/attention/ops/triton_unified_attention.py
+2 -1
@@ -674,7 +674,8 @@ def unified_attention(
674 num_queries_per_kv = num_query_heads // num_kv_heads
675 head_size = q.shape[2]
676
677 - BLOCK_M = 16
677 + BLOCK_M = 16 if num_queries_per_kv <= 16 else triton.next_power_of_2(
678 + num_queries_per_kv)
679 BLOCK_Q = BLOCK_M // num_queries_per_kv
680
681 # Ideally we would launch with kernel with: