Hi Jeff, is there (still) any reason to use explicit clone() instead of pthreads to spawn UML kernel threads? While playing with a patch to finally move os_nsecs to proper CLOCK_MONOTONIC, I noticed some subtle side-effect: We need to link against librt for clock_gettime, but that indirectly drags in libpthread. Now gdb gets unhappy when you try to debug the UML kernel. It assumes that pthreads are used, but fails to find their IDs and terminates the session. So the obvious approach appears to be converting kernel threads to pthreads - if there aren't any know pitfalls. Jan