Comment 6 for bug 760413

So at the moment qemu doesn't support emulating threaded x86 programs in linux-user mode. (-> target_nptl isn't set in configure for x86 targets). I think this is because the target-i386 code doesn't have the necessary support for bouncing atomic memory access ops up to the linux-user top level loop to be implemented with mutexes, the way the arm/mips/ppc/alpha targets do. This isn't a trivial feature to add, unfortunately.