I would also prefer to maintain symmetry here. Your argument is moot,
why diverge a small part of one API just because it is not used much?
Everyone using the spin_lock functions learns the weird interface pretty
fast. If you are in a rare situation where you have to use the trylock
versions, you would really expect them to be used equivalently.
It is weird but diverging it doesn't make it any better.
I agree that this argument of Ingo's is not a very good one... ;)