Network throughput not reaching line rate. Need clarification on iflib.

[Daniel Ebdrup Jensen]

On Fri, Feb 28, 2020 at 7:39 PM Bruce A. Mah <bmah at kitchenlab.org> wrote:

> [Resending with a From: address that hopefully works better.]
>
> If memory serves me right, Daniel Ebdrup Jensen wrote:
> > Yes, iperf3 will default to single-threaded packet generation, et al.
> which
> > favours fast cores with frequency boosting facilities.
> > You might want to use iperf2 as that's properly multi-threaded, or you
> can
> > use pkt-gen out of src/tools/tools/netmap/ or ports/net/pkt-gen.
>
> While it's true that iperf3 is single-threaded, it should be capable of
> saturating a 10GE link with a single TCP connection, given proper
> command-line arguments (in particular, specifying a sufficiently large
> socket-buffer size with the -w option).
>
> But based on the symptom of packet loss, I'd say the single-threaded vs.
> multi-threaded argument might not be relevant to the problem that the OP
> has.
>
> Bruce.
>
> > On Fri, Feb 28, 2020 at 10:35 AM Hans Petter Selasky <hps at selasky.org>
> > wrote:
> >
> >> On 2020-02-28 10:03, Rajesh Kumar wrote:
> >>> Hi FreeBSD team,
> >>>
> >>> I am writing a network driver using iflib framework and using "iperf3"
> >> tool
> >>> for performance testing.
> >>>
> >>
> >> Is there any difference with "iperf" tool and using multiple threads? I
> >> think iperf3 is single threaded ???
> >>
> >> --HPS
> >>
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>

Oh, I didn't mean to imply that that wasn't part of the issue - I'm sorry
if I made it sound like that.
I was just confirming what Hans was asking, and possibly using the excuse
to mention some things in base/ports that I think are also pretty neat. :)

Also no longer top-posting, which was rather ghastly of me. I apologise.