Re: [xdp-hints] [PATCH bpf-next v2 8/8] selftests/bpf: Simple program to dump XDP RX metadata

From: Stanislav Fomichev <sdf@google.com>
To: "Toke Høiland-Jørgensen" <toke@redhat.com>
Cc: bpf@vger.kernel.org, ast@kernel.org, daniel@iogearbox.net,
	andrii@kernel.org, martin.lau@linux.dev, song@kernel.org,
	yhs@fb.com, john.fastabend@gmail.com, kpsingh@kernel.org,
	haoluo@google.com, jolsa@kernel.org,
	David Ahern <dsahern@gmail.com>, Jakub Kicinski <kuba@kernel.org>,
	Willem de Bruijn <willemb@google.com>,
	Jesper Dangaard Brouer <brouer@redhat.com>,
	Anatoly Burakov <anatoly.burakov@intel.com>,
	Alexander Lobakin <alexandr.lobakin@intel.com>,
	Magnus Karlsson <magnus.karlsson@gmail.com>,
	Maryam Tahhan <mtahhan@redhat.com>,
	xdp-hints@xdp-project.net, netdev@vger.kernel.org
Subject: Re: [xdp-hints] [PATCH bpf-next v2 8/8] selftests/bpf: Simple program to dump XDP RX metadata
Date: Wed, 23 Nov 2022 10:29:23 -0800	[thread overview]
Message-ID: <CAKH8qBsSFg+3ULN-+aqabXZJRVwPtq9P71d0VZCuT2tMrx4DHw@mail.gmail.com> (raw)
In-Reply-To: <877czlvj9x.fsf@toke.dk>

On Wed, Nov 23, 2022 at 6:26 AM Toke Høiland-Jørgensen <toke@redhat.com> wrote:
>
> Stanislav Fomichev <sdf@google.com> writes:
>
> > +static int rxq_num(const char *ifname)
> > +{
> > +     struct ethtool_channels ch = {
> > +             .cmd = ETHTOOL_GCHANNELS,
> > +     };
> > +
> > +     struct ifreq ifr = {
> > +             .ifr_data = (void *)&ch,
> > +     };
> > +     strcpy(ifr.ifr_name, ifname);
> > +     int fd, ret;
> > +
> > +     fd = socket(AF_UNIX, SOCK_DGRAM, 0);
> > +     if (fd < 0)
> > +             error(-1, errno, "socket");
> > +
> > +     ret = ioctl(fd, SIOCETHTOOL, &ifr);
> > +     if (ret < 0)
> > +             error(-1, errno, "socket");
> > +
> > +     close(fd);
> > +
> > +     return ch.rx_count;
> > +}
>
> mlx5 uses 'combined' channels, so this returns 0. Changing it to just:
>
> return ch.rx_count ?: ch.combined_count;
>
> works though :)

Perfect, will do the same :-) Thank you for running and testing!

> -Toke
>