On Thu, 25 Jan 2018 23:15:17 +0100 Toke Høiland-Jørgensen <toke@xxxxxxx> wrote: > Dave Taht <dave.taht@xxxxxxxxx> writes: > > > https://blog.apnic.net/2018/01/22/ruru-real-time-wide-area-tcp-latency-monitoring/ > > Neat! The packet tapping part could probably be implemented in XDP to > avoid the DPDK space heater... ;) I was thinking the exact same thing ;-) It should be fairly simple to write a XDP/eBPF program, that timestamp via bpf_ktime_get_ns() and queue the events via a perf ring-buffer via bpf_perf_event_output() (the only kernel example is [1]). And a userspace side tool[2] that reads these perf_event's. Cc. xdp-newbies@xxxxxxxxxxxxxxx hoping someone want to give it a go? [1] https://github.com/torvalds/linux/blob/master/samples/bpf/trace_output_kern.c [2] https://github.com/torvalds/linux/blob/master/samples/bpf/trace_output_user.c -- Best regards, Jesper Dangaard Brouer MSc.CS, Principal Kernel Engineer at Red Hat LinkedIn: http://www.linkedin.com/in/brouer
|