Re: [PATCH net-next v10] net: reduce ARFS flow updates by checking LLC affinity

[Neal Cardwell]

On Fri, Oct 9, 2026 at 10:05 AM chuang <nashuiliang@xxxxxxxxx> wrote:
>
> On Thu, Oct 8, 2026 at 10:14 PM Neal Cardwell <ncardwell@xxxxxxxxxx> wrote:
> >
> > On Thu, Oct 8, 2026 at 9:33 AM Chuang Wang <nashuiliang@xxxxxxxxx> wrote:
> > >
> > ...
> > > --- a/net/core/sysctl_net_core.c
> > > +++ b/net/core/sysctl_net_core.c
> > > @@ -560,6 +560,13 @@ static struct ctl_table net_core_table[] = {
> > >                 .mode           = 0644,
> > >                 .proc_handler   = rps_sock_flow_sysctl
> > >         },
> > > +       {
> > > +               .procname       = "rps_feat_llc_affinity",
> > > +               .data           = &rps_feat_llc_affinity.key,
> > > +               .maxlen         = sizeof(rps_feat_llc_affinity.key),
> > > +               .mode           = 0644,
> > > +               .proc_handler   = proc_do_static_key
> > > +       },
> >
> > Having "feat_" in the name of a sysctl seems redundant, since most
> > sysctls are features.
> >
> > Also, the name seems overly broad, as it could also apply to other
> > RPS/RFS mechanisms leveraging LLC affinity, for which we might want
> > separate sysctl control knobs. I'd suggest perhaps something more
> > specific, like "rps_llc_affinity_for_set_cpu".
>
> How about arfs_llc_affinity or rfs_accel_llc_affinity or
> rfs_accel_llc_affinity_steer?
>
> The knob only gates the aRFS (CONFIG_RFS_ACCEL) hardware steering
> update in set_rps_cpu(), so scoping the name to aRFS describes exactly
> what it controls.

Of those options, arfs_llc_affinity sounds most appealing IMHO. But
let's see what Eric and others propose.

best,
neal