From: Maciej Fijalkowski <maciejromanfijalkowski@gmail.com>
To: Jesper Dangaard Brouer <brouer@redhat.com>
Cc: daniel@iogearbox.net, ast@kernel.org, netdev@vger.kernel.org,
jakub.kicinski@netronome.com
Subject: Re: [PATCH bpf-next v4 5/7] samples/bpf: Add a "force" flag to XDP samples
Date: Wed, 30 Jan 2019 19:12:48 +0100 [thread overview]
Message-ID: <20190130191248.00000167@gmail.com> (raw)
In-Reply-To: <20190129123405.787746f7@redhat.com>
On Tue, 29 Jan 2019 12:34:05 +0100
Jesper Dangaard Brouer <brouer@redhat.com> wrote:
> On Tue, 29 Jan 2019 09:00:00 +0100
> Jesper Dangaard Brouer <brouer@redhat.com> wrote:
>
> > On Mon, 28 Jan 2019 20:16:11 +0100
> > Maciej Fijalkowski <maciejromanfijalkowski@gmail.com> wrote:
> >
> > > From: Maciej Fijalkowski <maciej.fijalkowski@intel.com>
> > >
> > > Make xdp samples consistent with iproute2 behavior and set the
> > > XDP_FLAGS_UPDATE_IF_NOEXIST by default when setting the xdp program on
> > > interface. Provide an option for user to force the program loading,
> > > which as a result will not include the mentioned flag in
> > > bpf_set_link_xdp_fd call.
> >
> > I like the idea, but what is the error message users get after this
> > change?
>
> $ sudo ./xdp1 mlx5p1 &
> [1] 9768
>
> $ sudo ./xdp1 mlx5p1
> link set xdp fd failed
>
> This error message is a little too generic to be a good user experience.
> The kernel (in dev_change_xdp_fd) will return errno -EBUSY (-16), but
> we don't use or report the return value in these sample programs.
>
> If my QA see this error message, I will still get an error report
> bugzilla that I need to spend time on investigating. Can we please
> improve this error message?
>
> If you are really cool you get inspired by (or use) libbpf_strerror()
> code avail in tools/lib/bpf/libbpf_errno.c. Default strerror(EBUSY)
> will return "Device or resource busy", but maybe we can do slightly
> better and report something more meaningful for this XDP context.
>
I'll post a v5 with libbpf_strerror() usage when bpf_set_link_xdp_fd failed in
samples but at this point it will only give us a standard "device or resource
busy" error, so if we need some more meaningful message that libbpf will give
us then I guess we need to define a new libbpf_errno entry (as well as entry in
libbpf_strerror_table for this new errno value) and set the errno in
bpf_set_link_xdp_fd in case of a failure?
next prev parent reply other threads:[~2019-01-30 18:13 UTC|newest]
Thread overview: 21+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-01-28 19:16 [PATCH bpf-next v4 0/7] xdp: Avoid unloading xdp prog not attached by sample Maciej Fijalkowski
2019-01-28 19:16 ` [PATCH bpf-next v4 1/7] libbpf: Add a helper for retrieving a map fd for a given name Maciej Fijalkowski
2019-01-28 20:49 ` John Fastabend
2019-01-28 19:16 ` [PATCH bpf-next v4 2/7] samples/bpf: xdp_redirect_cpu have not need for read_trace_pipe Maciej Fijalkowski
2019-01-28 20:50 ` John Fastabend
2019-01-28 19:16 ` [PATCH bpf-next v4 3/7] samples/bpf: Convert XDP samples to libbpf usage Maciej Fijalkowski
2019-01-28 19:16 ` [PATCH bpf-next v4 4/7] samples/bpf: Extend RLIMIT_MEMLOCK for xdp_{sample_pkts, router_ipv4} Maciej Fijalkowski
2019-01-28 20:54 ` John Fastabend
2019-01-28 19:16 ` [PATCH bpf-next v4 5/7] samples/bpf: Add a "force" flag to XDP samples Maciej Fijalkowski
2019-01-28 20:57 ` John Fastabend
2019-01-29 8:00 ` Jesper Dangaard Brouer
2019-01-29 11:34 ` Jesper Dangaard Brouer
2019-01-30 18:12 ` Maciej Fijalkowski [this message]
2019-01-30 19:08 ` Jesper Dangaard Brouer
2019-01-31 2:26 ` Jakub Kicinski
2019-01-31 20:19 ` Jesper Dangaard Brouer
2019-01-28 19:16 ` [PATCH bpf-next v4 6/7] libbpf: Add a support for getting xdp prog id on ifindex Maciej Fijalkowski
2019-01-28 21:07 ` John Fastabend
2019-01-30 17:53 ` Maciej Fijalkowski
2019-01-28 19:16 ` [PATCH bpf-next v4 7/7] samples/bpf: Check the prog id before exiting Maciej Fijalkowski
2019-01-28 21:10 ` John Fastabend
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20190130191248.00000167@gmail.com \
--to=maciejromanfijalkowski@gmail.com \
--cc=ast@kernel.org \
--cc=brouer@redhat.com \
--cc=daniel@iogearbox.net \
--cc=jakub.kicinski@netronome.com \
--cc=netdev@vger.kernel.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.