mm: Add free_ram()

Add the free_ram() API and a means to install implementations of the
freer (I.E. the RAM cache).

comfy/model_management.py

@@ -445,6 +445,20 @@ try:
 except:
     logging.warning("Could not pick default device.")
 
+current_ram_listeners = set()
+
+def register_ram_listener(listener):
+    current_ram_listeners.add(listener)
+
+def unregister_ram_listener(listener):
+    current_ram_listeners.discard(listener)
+
+def free_ram(extra_ram=0, state_dict={}):
+    for tensor in state_dict.values():
+        if isinstance(tensor, torch.Tensor):
+            extra_ram += tensor.numel() * tensor.element_size()
+    for listener in current_ram_listeners:
+        listener.free_ram(extra_ram)
 
 current_loaded_models = []
 

execution.py

@@ -613,13 +613,21 @@ async def execute(server, dynprompt, caches, current_item, extra_data, executed,
 
 class PromptExecutor:
     def __init__(self, server, cache_type=False, cache_args=None):
+        self.caches = None
         self.cache_args = cache_args
         self.cache_type = cache_type
         self.server = server
         self.reset()
 
     def reset(self):
+        if self.caches is not None:
+            for cache in self.caches.all:
+                comfy.model_management.unregister_ram_listener(cache)
+
         self.caches = CacheSet(cache_type=self.cache_type, cache_args=self.cache_args)
+
+        for cache in self.caches.all:
+            comfy.model_management.register_ram_listener(cache)
         self.status_messages = []
         self.success = True