### What this PR does / why we need it?
Follow https://github.com/vllm-project/vllm/pull/37425,
https://github.com/vllm-project/vllm-omni/pull/1982
Copied from them:
Notice that `hasattr(self.model, "flush_pending_metadata")` cost 6ms per
decode step when profiling Qwen3 Omni.
The original `CUDAGraphWrapper.__getattr__` raises:
```python
raise AttributeError(f"... cudagraph wrapper: {self.runnable}")
```
When hasattr() is called for a non-existent attribute, Python internally
calls __getattr__ which constructs this AttributeError. The
{self.runnable} triggers `__repr__()` on the underlying model (e.g.,
`Qwen3OmniMoeForConditionalGeneration`), which recursivelytraverses the
entire nn.Module tree to generate an 18,000+ character string. This
takes ~6-7ms per call.
Since `hasattr(self.model, "flush_pending_metadata") ` is called every
decode step in the Talker forward path, this adds ~6ms overhead per
step, severely impacting audio inter-chunk latency (ICL).
```Python
hasattr(self.model, "flush_pending_metadata")
→ getattr(self.model, "flush_pending_metadata")
→ not found in CUDAGraphWrapper.__dict__
→ not found in the CUDAGraphWrapper class hierarchy
→ triggers CUDAGraphWrapper.__getattr__("flush_pending_metadata")
→ hasattr(self.runnable, "flush_pending_metadata") # runnable also doesn't have it
→ executes raise AttributeError(f"... {self.runnable}")
→ Python needs to construct the exception object
→ the f-string triggers self.runnable.__repr__()
→ Qwen3OmniMoeForConditionalGeneration.__repr__()
→ recursively traverses the entire nn.Module tree
→ generates a 18,000+ character string
→ takes ~6 ms
→ AttributeError object is created
→ hasattr catches the AttributeError and returns False
→ the 18,000-character string is immediately discarded (no one ever sees it)
```
### Does this PR introduce _any_ user-facing change?
NO.
### How was this patch tested?
See https://github.com/vllm-project/vllm-omni/pull/1982
- vLLM version: v0.17.0
- vLLM main:
4497431df6
---------
Signed-off-by: gcanlin <canlinguosdu@gmail.com>
e68464a1d6