[Model][Feat] Support Minimax-H3 quality grading requests through dynamic loading/unloading with Cache-DiT (#5853)

Signed-off-by: mglyn <1203789601@qq.com>

vllm_omni/diffusion/worker/diffusion_model_runner.py

@@ -32,7 +32,13 @@ from vllm_omni.diffusion.compile import regionally_compile
 from vllm_omni.diffusion.data import DiffusionOutput, OmniDiffusionConfig
 from vllm_omni.diffusion.forward_context import set_forward_context
 from vllm_omni.diffusion.model_loader.diffusers_loader import DiffusersPipelineLoader
-from vllm_omni.diffusion.models.interface import SupportsPromptUpdate, supports_prompt_update, supports_step_execution
+from vllm_omni.diffusion.models.interface import (
+    SupportsPromptUpdate,
+    adopt_request_scoped_cache_dit,
+    is_request_scoped_cache_dit_enabled,
+    supports_prompt_update,
+    supports_step_execution,
+)
 from vllm_omni.diffusion.offloader import get_offload_backend
 from vllm_omni.diffusion.registry import _NO_CACHE_ACCELERATION
 from vllm_omni.diffusion.request import OmniDiffusionRequest
@@ -304,7 +310,19 @@ class DiffusionModelRunner(OmniConnectorModelRunnerMixin):
                 self.cache_backend = None
                 self.od_config.cache_backend = None
             else:
+                # Install configured cache capability once at startup. A model
+                # may explicitly adopt the enabled Cache-DiT backend and then
+                # own all later request-boundary enable/disable transitions.
                 self.cache_backend.enable(self.pipeline)
+                if str(self.od_config.cache_backend).lower() == "cache_dit" and adopt_request_scoped_cache_dit(
+                    self.pipeline,
+                    self.cache_backend,
+                ):
+                    logger.info(
+                        "Pipeline %s owns request-scoped Cache-DiT transitions.",
+                        type(self.pipeline).__name__,
+                    )
+                    self.cache_backend = None
 
         # Install prompt-embedding cache (transparent wrapper around
         # ``pipeline.encode_prompt``). Enabled via config or env var; a no-op
@@ -523,11 +541,11 @@ class DiffusionModelRunner(OmniConnectorModelRunnerMixin):
             if is_primary and prompt_embed_cache is not None:
                 logger.debug("prompt-embed cache: %s", prompt_embed_cache.stats())
 
+            runner_cache_dit_enabled = self.cache_backend is not None and self.cache_backend.is_enabled()
             if (
-                self.cache_backend is not None
-                and self.cache_backend.is_enabled()
-                and od_config.cache_backend == "cache_dit"
+                od_config.cache_backend == "cache_dit"
                 and od_config.enable_cache_dit_summary
+                and (runner_cache_dit_enabled or is_request_scoped_cache_dit_enabled(self.pipeline))
             ):
                 cache_summary(self.pipeline, details=True)