Re: [PATCH net-next] net: shaper: Reject zero weight in shaper config

[Mohsin Bashir]

On 4/13/26 2:50 PM, Jakub Kicinski wrote:
> On Fri, 10 Apr 2026 15:51:23 -0700 Mohsin Bashir wrote:
> > A zero weight is meaningless for DWRR scheduling and can cause
> > starvation of the affected node. Add a min-value constraint to
> > the weight attribute in the net_shaper netlink spec so that zero
> > is rejected at the netlink policy level.
> >
> > Found while prototyping a new driver, existing drivers are not
> > affected.
>
> AI review points out that if the netlink attr is not present core will
> leave the DWRR weight as 0 in the struct. I guess we need to think this
> thru a little more carefully. What should the "default" weight be?
> What if user specifies weights only for subset of leaves?
>
> This part of the uAPI seems under-defined.
>
> Maybe a better adjustment would be to make core set the weight to 1
> automatically if the user has not defined it? Only when sending it to
> the driver tho, because we'd still want it to not be reported back to
> user space. Not sure how hairy it'd get code-wise.

Interesting!!
Let me look at the big picture here and re-spin.