Hey, yeah, they are using CLOCK_MONOTONIC for the event loop exactly for that. I think it might be possible to fix the SO_TIMESTAMP wall-clock problem by using

Hey, yeah, they are using CLOCK_MONOTONIC for the event loop exactly for that. I think it might be possible to fix the SO_TIMESTAMP wall-clock problem by using it not to measure duration between ping send and ping receive, but to measure kernel-userspace latency only. That is: measure ping send/recv with MONOTONIC, and subtract the kernel-to-userspace delay from that measurement to reduce jitter. The kernel-to-userspace delay can be done using SO_TIMESTAMP + wall clock. With such algo only the time change in the very short window between kernel-to-userspace would impact the readings. Another semi-related issue https://github.com/iputils/iputils/issues/480 https://github.com/iputils/iputils/issues/480