Does gem5 support NPTL threads by default?

[kiriakaras]

Hi, I am trying to use SMT on a single core setup. I have been able to run 2 workloads on the same core successfully, but when I try to run a simple test where 2 threads are created and joined, execution never terminates. In both tests I use the --smt argument, otherwise pthread_create returns error value 11). Does gem5 support the use of NPTL threads, or relies only to m5threads for thread operations?