@knc1: Well, of course I'm assuming you're running a kernel >= your kernel headers
.
I was speaking mostly from an x86/x86_64 POV, so I may be missing some stuff on the embedded/ARM front. (And I do use NPTL threading in my ARM TC, linux threads haven't been supported in the main glibc release tarballs since quite a while, if I remember correctly).
And pthreads doesn't necessarily means !NPTL, it supports both LT & NPTL, but it's been a while since I've seen a system with both threading implementation installed...