So in the silberschatz O.S book it says Windows uses one to one model (mapping user level threads to kernel level threads)
but why? i thought many to many and two level models are much better, specially two level model, so why not use the two level mode or many to many? whats the benefit compared to other models and isn't there some overhead and limitation(like number of threads) because of using one to one?
overall, if someone wants to create a new O.S, how should he know which model to choose?