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Fall back if flashinfer comm module not found #20936

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Merged
merged 1 commit into from
Jul 14, 2025
Merged

Fall back if flashinfer comm module not found #20936

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13 changes: 8 additions & 5 deletions vllm/compilation/collective_fusion.py
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Original file line number Diff line number Diff line change
Expand Up @@ -20,10 +20,12 @@
from .vllm_inductor_pass import VllmInductorPass

if find_spec("flashinfer"):
import flashinfer.comm as flashinfer_comm

flashinfer_comm = (flashinfer_comm if hasattr(
flashinfer_comm, "trtllm_allreduce_fusion") else None)
try:
import flashinfer.comm as flashinfer_comm
flashinfer_comm = (flashinfer_comm if hasattr(
flashinfer_comm, "trtllm_allreduce_fusion") else None)
except ImportError:
Comment on lines +23 to +27
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@gemini-code-assist gemini-code-assist bot Jul 14, 2025

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medium

To avoid shadowing the outer scope flashinfer_comm variable, it would be clearer to assign the module directly to comm and then conditionally assign it to flashinfer_comm if the attribute exists.

Suggested change
try:
import flashinfer.comm as flashinfer_comm
flashinfer_comm = (flashinfer_comm if hasattr(
flashinfer_comm, "trtllm_allreduce_fusion") else None)
except ImportError:
try:
import flashinfer.comm as comm
if hasattr(comm, "trtllm_allreduce_fusion"):
flashinfer_comm = comm
except ImportError:
flashinfer_comm = None

flashinfer_comm = None
else:
flashinfer_comm = None
from vllm.platforms import current_platform
Expand Down Expand Up @@ -411,7 +413,8 @@ def __init__(self, config: VllmConfig, max_token_num: int):
use_fp32_lamport = self.model_dtype == torch.float32
if flashinfer_comm is None:
logger.warning(
"Flashinfer is not installed, skipping allreduce fusion pass")
"Flashinfer is not installed or comm module not found, "
"skipping allreduce fusion pass")
return
# Check if the world size is supported
if self.tp_size not in _FI_MAX_SIZES:
Expand Down