Hi, for those who haven't followed the endless "RTDM and Timer functions" thread: we are currently discussing a way to provide high-resolution timestamps in periodic mode for RTDM users. It was suggested to use the TSC for this, but I noted that this source will not be in sync with the periodic system timer and may even be out of sync across multiple CPUs. A straight-forward approach to overcome this might be to record the current TSC value together with the current jiffies in xntimer_do_tick_periodic(). This tuple (per CPU) could then be provided to skin implementers in order to let them offer a high-resolution timestamp source even in periodic mode. Hmm, sounds too simple actually, so I'm waiting now for someone pointing out the pitfalls. Jan