[LibreQoS] Fwd: xmit_more?

Dave Taht dave.taht at gmail.com
Mon Oct 17 15:05:20 EDT 2022

I was looking over some very old work, here: https://lwn.net/Articles/615238/

about BQL and xmit_more in the context  of the mvpp2 work going on over here:


Courtesy, jesper:

"I'm on PTO and traveling, so i don't have access to my bpftrace
scripts (here from the hotel lobby).

And yes I usually just "code" a oneliner with bpftrace to measure the
bulking effect.

I coded the qdisc tx bulking and added a tracepoint for this purpose.

You can also use the pktgen scripts in samples/pktgen/ 03 to burst
packets to see the xmit more effect."


man. 17. okt. 2022 16.40 skrev Toke Høiland-Jørgensen <toke at redhat.com>:
> Dave Taht <dave.taht at gmail.com> writes:
> > On Mon, Oct 17, 2022 at 7:00 AM Toke Høiland-Jørgensen <toke at redhat.com> wrote:
> >>
> >> Dave Taht <dave.taht at gmail.com> writes:
> >>
> >> > This is an old blog from jesper from ages back. Is xmit_more on on
> >> > most drivers nowadays? Was it subsumed by something else?
> >>
> >> Definitely still a thing. As for driver support:
> >
> > Well, marcin just added bql support to the mvpp2, but not xmit_more,
> > apparently. He's still working out
> > ways to measure the improvement better, but it did work correctly in
> > the openwrt 5.15 build.
> >
> > There a good way to see xmit_more doing magic?
> Jesper has a bpftrace invocation that spits out a nice histogram (for
> both BQL and xmit_more). Hopefully he's willing to share that ;)
> -Toke

This song goes out to all the folk that thought Stadia would work:
Dave Täht CEO, TekLibre, LLC

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