glm-image: cache default HF processor to reduce input preprocessing latency (#3245)

Signed-off-by: lyj-jjj <liuyingjun5@huawei.com>
Co-authored-by: Hongsheng Liu <liuhongsheng4@huawei.com>

vllm_omni/model_executor/models/glm_image/glm_image_ar.py

@@ -24,6 +24,7 @@
 import math
 import os
 from collections.abc import Iterable, Mapping, Sequence
+from functools import lru_cache
 from typing import Annotated, Literal
 
 import torch
@@ -103,6 +104,15 @@ logger = init_logger(__name__)
 # === Multimodal Processing ===
 
 
+@lru_cache(maxsize=1)
+def _load_cached_glm_image_processor(processor_path: str, trust_remote_code: bool) -> GlmImageProcessor:
+    """Cache GLM-Image processor loading to avoid repeated from_pretrained cost."""
+    return GlmImageProcessor.from_pretrained(
+        processor_path,
+        trust_remote_code=trust_remote_code,
+    )
+
+
 class GlmImagePixelInputs(TensorSchema):
     """
     Schema for GLM-Image pixel inputs.
@@ -177,11 +187,22 @@ class GlmImageProcessingInfo(BaseProcessingInfo):
             if not os.path.exists(processor_path):
                 processor_path = model_path
 
-        # Load processor directly from the correct path
-        return GlmImageProcessor.from_pretrained(
-            processor_path,
-            trust_remote_code=self.ctx.model_config.trust_remote_code,
-            **kwargs,
+        trust_remote_code = self.ctx.model_config.trust_remote_code
+
+        # Keep dynamic override behavior when kwargs are provided, but use a
+        # cached instance for the default path to reduce per-request overhead.
+        # Default path (without kwargs): high frequency, stable, safely reuse cache;
+        # with kwargs: maintain precise semantics, construct instantly per call, avoid mismatch risk.
+        if kwargs:
+            return GlmImageProcessor.from_pretrained(
+                processor_path,
+                trust_remote_code=trust_remote_code,
+                **kwargs,
+            )
+
+        return _load_cached_glm_image_processor(
+            processor_path=processor_path,
+            trust_remote_code=trust_remote_code,
         )
 
     def get_data_parser(self) -> GlmImageDataParser: