Nothing. Linus doesn’t personally do coding on the kernel, he has a team who do that and he oversees it and makes the hard decisions.
Even that is not really the truth. There are dozens and dozens of teams that actually do the development, then there are people who coordinate and maintain certain parts of the kernel, merge in patches and make decisions. And then there’s Linus who does coordinate these people.
There are others who will take his place and the work will continue.
And most likely Greg K-H will take over the position that Linus has right now. He has been one of the most active maintainers and is probably “the number 2” behind Linus.
Even that is not really the truth. There are dozens and dozens of teams that actually do the development, then there are people who coordinate and maintain certain parts of the kernel, merge in patches and make decisions. And then there’s Linus who does coordinate these people.
And most likely Greg K-H will take over the position that Linus has right now. He has been one of the most active maintainers and is probably “the number 2” behind Linus.