Some specific questions about 5.x

[Alex]

Hi everybody!

I was so much enthusiastic about kernel threads implemented in 5.x but 
some ugly rumors spoiled my dreams :0)
So I want to get if these rumors are myths or not.

1.    Is it true that kernel threads are more "heavy" than userspace 
ones (pthread) and hence application with hundreds of threads will work 
evidently slower than that using pthreads due to more switching penalties?

2.    Is it true that even 5.x has no implementation for inter-process 
semaphores that are blocking calling thread only not the whole process 
as usually in FreeBSD?


Alex