On Sat, 23 Jan 2021 01:34:19 +0100 Toke Høiland-Jørgensen via Bloat <[email protected]> wrote:
> Hal Murray <[email protected]> writes: > > > Toke said: > >> Yeah, the overhead of CoDel itself (and even FQ-CoDel) is basically nil (as > >> in, we have not been able to measure it), when otherwise doing forwarding > >> using the regular Linux stack. > > > > I may be able to help with that. > > > > Are you familiar with Dick Sites' KUtrace? > > Stanford Seminar - KUtrace 2020 > > https://www.youtube.com/watch?v=2HE7tSZGna0 > > Nope - but from a quick glance it looks similar to what you can do with > 'perf'? :) Yes, but the 'perf' tool (mostly) uses sampling. I assume you want to catch latency outliers, right? I would probably recommend that you play with bpftrace[1], for processing all the events to catch the outliers. [1] https://github.com/iovisor/bpftrace As an example look at this bpftrace script[2], that I used for detecting latency issues, network hardIRQ-to-softirq latency. [2] https://github.com/xdp-project/xdp-project/blob/master/areas/latency/softirq_net_latency.bt -- Best regards, Jesper Dangaard Brouer MSc.CS, Principal Kernel Engineer at Red Hat LinkedIn: http://www.linkedin.com/in/brouer _______________________________________________ Bloat mailing list [email protected] https://lists.bufferbloat.net/listinfo/bloat
