Re: [PATCH bpf-next 0/8] Simplify xdp_do_redirect_map()/xdp_do_flush_map() and XDP maps

From: Andrii Nakryiko <andrii.nakryiko@gmail.com>
To: Daniel Borkmann <daniel@iogearbox.net>
Cc: "Jesper Dangaard Brouer" <brouer@redhat.com>,
	"Björn Töpel" <bjorn.topel@gmail.com>,
	Netdev <netdev@vger.kernel.org>,
	"Alexei Starovoitov" <ast@kernel.org>, bpf <bpf@vger.kernel.org>,
	"David Miller" <davem@davemloft.net>,
	"Jakub Kicinski" <jakub.kicinski@netronome.com>,
	"John Fastabend" <john.fastabend@gmail.com>,
	"Karlsson, Magnus" <magnus.karlsson@intel.com>,
	"Jonathan Lemon" <jonathan.lemon@gmail.com>,
	"Maciej Fijalkowski" <maciejromanfijalkowski@gmail.com>
Subject: Re: [PATCH bpf-next 0/8] Simplify xdp_do_redirect_map()/xdp_do_flush_map() and XDP maps
Date: Thu, 19 Dec 2019 14:56:04 -0800	[thread overview]
Message-ID: <CAEf4Bzb0=Uwf0V1u2k4cvucAnEFxG-g_TYcy6YZHUCACgiNFyg@mail.gmail.com> (raw)
In-Reply-To: <4e5cb0b0-14b9-5de9-4346-e4c2955e99a0@iogearbox.net>

On Thu, Dec 19, 2019 at 12:08 PM Daniel Borkmann <daniel@iogearbox.net> wrote:
>
> On 12/19/19 8:33 PM, Jesper Dangaard Brouer wrote:
> > On Wed, 18 Dec 2019 16:39:08 -0800
> > Andrii Nakryiko <andrii.nakryiko@gmail.com> wrote:
> >
> >> On Wed, Dec 18, 2019 at 4:04 AM Jesper Dangaard Brouer
> >> <brouer@redhat.com> wrote:
> >>>
> >>> On Wed, 18 Dec 2019 12:39:53 +0100
> >>> Björn Töpel <bjorn.topel@gmail.com> wrote:
> >>>
> >>>> On Wed, 18 Dec 2019 at 12:11, Jesper Dangaard Brouer <brouer@redhat.com> wrote:
> >>>>>
> >>>>> On Wed, 18 Dec 2019 11:53:52 +0100
> >>>>> Björn Töpel <bjorn.topel@gmail.com> wrote:
> >>>>>
> >>>>>>    $ sudo ./xdp_redirect_cpu --dev enp134s0f0 --cpu 22 xdp_cpu_map0
> >>>>>>
> >>>>>>    Running XDP/eBPF prog_name:xdp_cpu_map5_lb_hash_ip_pairs
> >>>>>>    XDP-cpumap      CPU:to  pps            drop-pps    extra-info
> >>>>>>    XDP-RX          20      7723038        0           0
> >>>>>>    XDP-RX          total   7723038        0
> >>>>>>    cpumap_kthread  total   0              0           0
> >>>>>>    redirect_err    total   0              0
> >>>>>>    xdp_exception   total   0              0
> >>>>>
> >>>>> Hmm... I'm missing some counters on the kthread side.
> >>>>>
> >>>>
> >>>> Oh? Any ideas why? I just ran the upstream sample straight off.
> >>>
> >>> Looks like it happened in commit: bbaf6029c49c ("samples/bpf: Convert
> >>> XDP samples to libbpf usage") (Cc Maciej).
> >>>
> >>> The old bpf_load.c will auto attach the tracepoints... for and libbpf
> >>> you have to be explicit about it.
> >>
> >> ... or you can use skeleton, which will auto-attach them as well,
> >> provided BPF program's section names follow expected naming
> >> convention. So it might be a good idea to try it out.
> >
> > To Andrii, can you provide some more info on how to use this new
> > skeleton system of yours?  (Pointers to code examples?)
>
> There's a man page ;-)
>
> https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next.git/tree/tools/bpf/bpftool/Documentation/bpftool-gen.rst

Also see runqslower patch set for end-to-end set up. There are a bunch
of selftests already using skeletons (test_attach_probe,
test_core_extern, test_skeleton).