Re: [PATCH bpf-next] samples/bpf: xdp_redirect_cpu: Add mprog-disable to optstring.

[Daniel Borkmann]

On 8/4/21 7:57 PM, Matt Cover wrote:
> On Sat, Jul 31, 2021 at 8:25 AM Kumar Kartikeya Dwivedi
> <memxor@xxxxxxxxx> wrote:
> > On Sat, Jul 31, 2021 at 06:26:32AM IST, Matthew Cover wrote:
> > > Commit ce4dade7f12a ("samples/bpf: xdp_redirect_cpu: Load a eBPF program
> > > on cpumap") added the following option, but missed adding it to optstring:
> > > - mprog-disable: disable loading XDP program on cpumap entries
> > >
> > > Add the missing option character.
> >
> > I made some changes in this area in [0], since the support was primarily to do
> > redirection from the cpumap prog, so by default we don't install anything now
> > and only do so if a redirection interface is specified (and use devmap instead).
> > So this option won't be used anyway going forward (since we don't install a
> > dummy XDP_PASS program anymore) if it gets accepted.
> >
> > [0]: https://lore.kernel.org/bpf/20210728165552.435050-1-memxor@xxxxxxxxx
> >
> > PS: I can restore it again if this is something really used beyond redirecting
> > to another device (i.e. with custom BPF programs). Any feedback would be helpful.
>
> Hey Kartikeya. I happened to be looking through this code to get a
> feel for using CPUMAP for custom steering (e.g. RSS on encapsulated
> packets) in XDP and noticed the missing option character. Figured it
> was worth doing a quick patch and test.
>
> Unfortunately, I'm not able to say much on your changes as I'm still
> getting familiarized with this code. It looks like your submission is
> in need of a rebase; v3 has been marked "Changes Requested" in
> patchwork [0]. As I see things, It'd be good to get this fix in there
> for now, whether or not the code is removed later.

Yeap, given this fix in here is tiny & valid either way, I took it in for now, and
when Kartikeya's rework eventually drops the whole option, so be it. ;)

Applied, thanks!