The following method has a performance problem (build 2.0.2-b10):
public UIComponent createComponent(FacesContext context, Resource
componentResource) throws FacesException
In line 976 the class loader is called, which is quite expensive. If you make
heavy use of composite components, the performance decreases dramatically under
heavy load because the class loader is synchronized.
You should remember that you already looked for a class and didn't find it. You
could simply map an inner class (e.g. ComponentNotFound) to the class name in
the component map.