Let's map all the SGA components

Hi guys,
I've been trying to obtain ALL the components in the SGA, I want to create a complete map of it and a way to look how much memory each component consume, I want to share this once I have it done....BUT...I can't find a way to see the amount of memory the REDO BUFFER is consuming....

I attached a couple of docs if you are interested, they are my first attempt to create a map of the SGA, they need more work...obviously ;)

I expect we all can work on this!!