On Mon, Jun 6, 2022 at 3:38 AM Kurt Kanzenbach <kurt@xxxxxxxxxxxxx> wrote:
>
> From: Jesper Dangaard Brouer <brouer@xxxxxxxxxx>
>
> Commit 3dc6ffae2da2 ("timekeeping: Introduce fast accessor to clock tai")
> introduced a fast and NMI-safe accessor for CLOCK_TAI. Especially in time
> sensitive networks (TSN), where all nodes are synchronized by Precision Time
> Protocol (PTP), it's helpful to have the possibility to generate timestamps
> based on CLOCK_TAI instead of CLOCK_MONOTONIC. With a BPF helper for TAI in
> place, it becomes very convenient to correlate activity across different
> machines in the network.
That's a fresh feature. It feels risky to bake it into uapi already.
imo it would be better to annotate tk_core variable in vmlinux BTF.
Then progs will be able to read all possible timekeeper offsets.
