On Wed, Sep 13, 2023 at 09:28:34AM -0400, Josef 'Jeff' Sipek wrote: > However, I also see that cooked_time (i.e., sys_ts+correction) is fed into > SPF_AccumulateSample as sample->time. Later on, combine_selected_samples > makes use of ->time to calculate various things. So, it looks like any > error due to ns->us truncation will affect the math here. At a glance, I > can't tell if the effect is so small that it can be ignored or if there is > any benefit to avoiding the [0,999] ns error.
It's so small that it can be ignored. The time at which the offset was measured is not that important. The frequency error between the reference and current clock is minimized by the control loop, usually to less than a ppm. Even if it was 1000 ppm, over a 1 microsecond interval that would still make only 1 nanosecond of phase error. It's well hidden in the noise. The main purpose of that timestamp is detection of stale and out-of-order samples. -- Miroslav Lichvar -- To unsubscribe email chrony-dev-requ...@chrony.tuxfamily.org with "unsubscribe" in the subject. For help email chrony-dev-requ...@chrony.tuxfamily.org with "help" in the subject. Trouble? Email listmas...@chrony.tuxfamily.org.
