Messages in this thread | | | From | Oleksandr Natalenko <> | Subject | Re: TCP and BBR: reproducibly low cwnd and bandwidth | Date | Fri, 16 Feb 2018 18:37:08 +0100 |
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Hi.
On pátek 16. února 2018 17:25:58 CET Eric Dumazet wrote: > The way TCP pacing works, it defaults to internal pacing using a hint > stored in the socket. > > If you change the qdisc while flow is alive, result could be unexpected.
I don't change a qdisc while flow is alive. Either the VM is completely restarted, or iperf3 is restarted on both sides.
> (TCP socket remembers that one FQ was supposed to handle the pacing) > > What results do you have if you use standard pfifo_fast ?
Almost the same as with fq_codel (see my previous email with numbers).
> I am asking because TCP pacing relies on High resolution timers, and > that might be weak on your VM.
Also, I've switched to measuring things on a real HW only (also see previous email with numbers).
Thanks.
Regards, Oleksandr
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