Before experimenting can't I ask someone whether relevant experiments were made or not? if I am not supposed to do that then I totally agree with you, sir.
I tried asking in python-ideas and one of the replies was "I gather there have been some experiments along these lines as part
of efforts to remove the GIL. You might like to research them to find out how much success they've had."
What I can interpret from this reply is there are some experiments regarding this topic but I don't know where they are. Then I asked him where could I find them but didn't get any answer to that.
Then how have I got my answers?
I am so sorry if I am asking any inappropriate question here.
Raihan,
Nobody knows the answers to your questions ("can we optimize...", "where would I face problems...", "is there something I am missing?", "tell me the factors I should consider").
Your questions are somehow presented as if we *should* know the answers, and seem to insinuate that we should have investigated the techniques you mention. The answer to this is that we are doubtful that it will be easy to implement them in a fully backwards compatible way (and you'd be surprised how important backwards compatibility is).
The only thing I personally know about this topic is that Larry Hastings attempted a more sophisticated approach to multi-threaded reference counting without the GIL, and came up short despite putting a lot of effort in it. You should probably do some Googling on Gilectomy and find Larry's various annual updates. That is presumably what that python-ideas answer was referring to.
Good luck.