On Tue, Jun 21, 2016 at 11:49 AM, Stephan Mueller firstname.lastname@example.org wrote:
Am Dienstag, 21. Juni 2016, 11:11:42 schrieb John Stultz:
I don't see in the above an explanation of *why* you're using ktime_get_raw_ns() instead of ktime_get_ns().
Could you help me understand what the difference is or point me to some documentation? I understood that we only talked about the _raw variant.
Using specialized interfaces with subtle semantics w/o understanding them is sort of my concern here.
There are reasons why you might want to use the ktime_get_raw_ns() interface over ktime_get_ns(), but they have not been made clear in the comment. Arnd discussed some potential concerns that the freq adjustment done by ntp might be somewhat predictable/controlled by remote parties, which could have some effect in the calculation. That feels a little overly vague to me, but I'm no crypto expert, so if that is a reasonable concern, then it should be a conscious and documented decision.