Add aggressive VRAM cleanup for model switching

- Added _aggressive_vram_cleanup method to properly clear VRAM
- Moves model to CPU before deletion
- Deletes pipeline, vae, text_encoder, tokenizer explicitly
- Multiple rounds of gc.collect()
- Uses torch.cuda.synchronize() before clearing cache
- Increased delay to 5 seconds after cleanup

coderai

@@ -2164,6 +2164,78 @@ class ModelManager:
         self.backend: Optional[ModelBackend] = None
         self.backend_type: Optional[str] = None
         self.tool_parser = ToolCallParser()
+    
+    def _aggressive_vram_cleanup(self, model_manager):
+        """
+        Aggressively cleanup VRAM when switching between different model types.
+        This is more thorough than a simple cleanup() call.
+        """
+        import gc
+        import time
+        
+        try:
+            import torch
+            
+            # First, try to move model to CPU if it has a model attribute
+            if hasattr(model_manager, 'model') and model_manager.model is not None:
+                model = model_manager.model
+                
+                # If it's a diffusers pipeline, try to move to CPU first
+                if hasattr(model, 'to'):
+                    try:
+                        model.to('cpu')
+                    except:
+                        pass
+                
+                # Delete the model
+                del model
+            
+            # Also handle backend directly if it's different
+            if hasattr(model_manager, 'backend') and model_manager.backend is not None:
+                backend = model_manager.backend
+                
+                if hasattr(backend, 'model') and backend.model is not None:
+                    model = backend.model
+                    if hasattr(model, 'to'):
+                        try:
+                            model.to('cpu')
+                        except:
+                            pass
+                    del model
+                
+                if hasattr(backend, 'pipeline') and backend.pipeline is not None:
+                    del backend.pipeline
+                
+                if hasattr(backend, 'vae') and backend.vae is not None:
+                    del backend.vae
+                
+                if hasattr(backend, 'text_encoder') and backend.text_encoder is not None:
+                    del backend.text_encoder
+                
+                if hasattr(backend, 'tokenizer') and backend.tokenizer is not None:
+                    del backend.tokenizer
+            
+            # Force multiple rounds of garbage collection
+            for _ in range(3):
+                gc.collect()
+            
+            # Clear PyTorch cache
+            if torch.cuda.is_available():
+                torch.cuda.synchronize()
+                torch.cuda.empty_cache()
+            
+            # Add delay to allow Vulkan to release memory
+            time.sleep(2)
+            
+        except Exception as e:
+            print(f"Warning during aggressive VRAM cleanup: {e}")
+        finally:
+            # Try to cleanup the model manager itself
+            try:
+                if hasattr(model_manager, 'cleanup'):
+                    model_manager.cleanup()
+            except:
+                pass
         
     def load_model(self, model_name: str, backend_type: str = "auto", **kwargs):
         """
@@ -2607,29 +2679,12 @@ class MultiModelManager:
                         model_to_cleanup = self.models.get(key)
                         if model_to_cleanup is not None:
                             print(f"Unloading image model '{key}' from VRAM to reload text model")
-                            try:
-                                if hasattr(model_to_cleanup, 'cleanup') and callable(getattr(model_to_cleanup, 'cleanup')):
-                                    model_to_cleanup.cleanup()
-                                elif hasattr(model_to_cleanup, 'model') and model_to_cleanup.model is not None:
-                                    if hasattr(model_to_cleanup.model, 'cleanup'):
-                                        model_to_cleanup.model.cleanup()
-                            except Exception as e:
-                                print(f"Warning during cleanup of '{key}': {e}")
+                            self._aggressive_vram_cleanup(model_to_cleanup)
                         del self.models[key]
                 
-                # Force garbage collection and clear GPU cache
-                import gc
-                gc.collect()
-                try:
-                    import torch
-                    if torch.cuda.is_available():
-                        torch.cuda.empty_cache()
-                except:
-                    pass
-                
                 # Add a longer delay to allow VRAM to be freed (Vulkan needs more time)
                 import time
-                time.sleep(3)
+                time.sleep(5)
                 
                 # Now try to reload the default model
                 try:
@@ -2751,14 +2806,7 @@ class MultiModelManager:
                 model_to_cleanup = self.models.get(key)
                 if model_to_cleanup is not None:
                     print(f"Unloading image model '{key}' from VRAM to make room for text model")
-                    try:
-                        if hasattr(model_to_cleanup, 'cleanup') and callable(getattr(model_to_cleanup, 'cleanup')):
-                            model_to_cleanup.cleanup()
-                        elif hasattr(model_to_cleanup, 'model') and model_to_cleanup.model is not None:
-                            if hasattr(model_to_cleanup.model, 'cleanup'):
-                                model_to_cleanup.model.cleanup()
-                    except Exception as e:
-                        print(f"Warning during cleanup of '{key}': {e}")
+                    self._aggressive_vram_cleanup(model_to_cleanup)
                     del self.models[key]
         
         # Force garbage collection and clear GPU cache
@@ -2771,9 +2819,9 @@ class MultiModelManager:
         except:
             pass
         
-        # Add a small delay to allow VRAM to be freed
+        # Add a longer delay to allow VRAM to be freed (Vulkan needs more time)
         import time
-        time.sleep(1)
+        time.sleep(5)
         
         # Check if requested model is already loaded - if so, reuse it
         if requested_model in self.models: