Re: [PATCH net-next 0/2] net: xsk: add two sysctl knobs

[Willem de Bruijn <willemdebruijn.kernel@gmail.com>]

Jason Xing wrote:
> Hi Stanislav,
> 
> On Tue, Jun 17, 2025 at 9:11 AM Stanislav Fomichev <stfomichev@gmail.com> wrote:
> >
> > On 06/17, Jason Xing wrote:
> > > From: Jason Xing <kernelxing@tencent.com>
> > >
> > > Introduce a control method in the xsk path to let users have the chance
> > > to tune it manually.
> >
> > Can you expand more on why the defaults don't work for you?
> 
> We use a user-level tcp stack with xsk to transmit packets that have
> higher priorities than other normal kernel tcp flows. It turns out
> that enlarging the number can minimize times of triggering sendto
> sysctl, which contributes to faster transmission. it's very easy to
> hit the upper bound (namely, 32) if you log the return value of
> sendto. I mentioned a bit about this in the second patch, saying that
> we can have a similar knob already appearing in the qdisc layer.
> Furthermore, exposing important parameters can help applications
> complete their AI/auto-tuning to judge which one is the best fit in
> their production workload. That is also one of the promising
> tendencies :)

It would be informative to include this in the commit.

Or more broadly: suggestions for when and how to pick good settings
for these new tunables.