netdev.vger.kernel.org archive mirror
 help / color / mirror / Atom feed
From: Jesper Dangaard Brouer <brouer@redhat.com>
To: Saeed Mahameed <saeedm@mellanox.com>
Cc: "dsahern@gmail.com" <dsahern@gmail.com>,
	"thoiland@redhat.com" <thoiland@redhat.com>,
	"virtualization@lists.linux-foundation.org" 
	<virtualization@lists.linux-foundation.org>,
	"borkmann@iogearbox.net" <borkmann@iogearbox.net>,
	Tariq Toukan <tariqt@mellanox.com>,
	"john.fastabend@gmail.com" <john.fastabend@gmail.com>,
	"mst@redhat.com" <mst@redhat.com>,
	"jakub.kicinski@netronome.com" <jakub.kicinski@netronome.com>,
	"netdev@vger.kernel.org" <netdev@vger.kernel.org>,
	"jasowang@redhat.com" <jasowang@redhat.com>,
	"davem@davemloft.net" <davem@davemloft.net>,
	"makita.toshiaki@lab.ntt.co.jp" <makita.toshiaki@lab.ntt.co.jp>,
	brouer@redhat.com
Subject: Re: [PATCH net] virtio_net: Account for tx bytes and packets on sending xdp_frames
Date: Wed, 6 Feb 2019 14:48:14 +0100	[thread overview]
Message-ID: <20190206144814.46996933@carbon> (raw)
In-Reply-To: <140ecbe1e25f54f90d859cc696c4119aa96bc6eb.camel@mellanox.com>

On Wed, 6 Feb 2019 00:06:33 +0000
Saeed Mahameed <saeedm@mellanox.com> wrote:

> 3) Unrelated, In non XDP case, if skb allocation fails or driver fails
> to pass the skb up to the stack for somereason, should the driver
> increase rx packets ? IMHO the answer should be yes if we want to have
> similar behavior between XDP and non XDP cases.

I don't think "skb allocation fails" should increase rx packets
counter.  The difference is that these events are outside sysadm/users
control, and is an error detected inside the driver.  The XDP program
takes a policy choice to XDP_DROP a packet, which can be accounted
inside the XDP prog (as the samples show) or as we also discuss via a
more generic XDP-action counters.

That said, I took at quick look at driver code, and it seems this
behavior differs per driver... ixgbe and mlx5 does not count "skb
allocation fails" as RX-ed packets, while mlx4 seems to count them.


> But this could result in netdev->stats.rx_packets +
> netdev->stats.rx_dropped to be more than the actual rx-ed packets, is
> this acceptable ?

This is one reasons I think this is wrong.

--Jesper

  reply	other threads:[~2019-02-06 13:48 UTC|newest]

Thread overview: 27+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-01-31 11:40 [PATCH net] virtio_net: Account for tx bytes and packets on sending xdp_frames Toshiaki Makita
2019-01-31 15:25 ` Michael S. Tsirkin
2019-01-31 17:45   ` David Miller
2019-01-31 20:15     ` Jesper Dangaard Brouer
2019-02-01  1:53       ` Toshiaki Makita
2019-02-02 21:27       ` David Ahern
2019-02-04 11:53         ` Jesper Dangaard Brouer
2019-02-05  3:13           ` David Ahern
2019-02-06  0:06             ` Saeed Mahameed
2019-02-06 13:48               ` Jesper Dangaard Brouer [this message]
2019-02-06 15:52                 ` Jakub Kicinski
2019-02-07  7:48               ` Resource management for ndo_xdp_xmit (Was: [PATCH net] virtio_net: Account for tx bytes and packets on sending xdp_frames) Jesper Dangaard Brouer
2019-02-07 19:08                 ` Saeed Mahameed
2019-02-08 16:55                   ` Toke Høiland-Jørgensen
2019-02-08 22:49                     ` Saeed Mahameed
2019-02-08 23:17                   ` Saeed Mahameed
2019-02-09  0:18                     ` Saeed Mahameed
2019-02-09  2:05                       ` Jakub Kicinski
2019-02-09 16:56                         ` Toke Høiland-Jørgensen
2019-02-09 16:56                       ` Toke Høiland-Jørgensen
2019-02-08 16:02               ` [PATCH net] virtio_net: Account for tx bytes and packets on sending xdp_frames Jesper Dangaard Brouer
2019-04-18 14:24             ` Stats for XDP actions (was: Re: [PATCH net] virtio_net: Account for tx bytes and packets on sending xdp_frames) Toke Høiland-Jørgensen
2019-04-21  0:16               ` Stats for XDP actions David Ahern
2019-06-20 20:42                 ` Toke Høiland-Jørgensen
2019-06-21  0:42                   ` David Ahern
2019-06-21 13:57                     ` Toke Høiland-Jørgensen
2019-02-04  4:18 ` [PATCH net] virtio_net: Account for tx bytes and packets on sending xdp_frames David Miller

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=20190206144814.46996933@carbon \
    --to=brouer@redhat.com \
    --cc=borkmann@iogearbox.net \
    --cc=davem@davemloft.net \
    --cc=dsahern@gmail.com \
    --cc=jakub.kicinski@netronome.com \
    --cc=jasowang@redhat.com \
    --cc=john.fastabend@gmail.com \
    --cc=makita.toshiaki@lab.ntt.co.jp \
    --cc=mst@redhat.com \
    --cc=netdev@vger.kernel.org \
    --cc=saeedm@mellanox.com \
    --cc=tariqt@mellanox.com \
    --cc=thoiland@redhat.com \
    --cc=virtualization@lists.linux-foundation.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 a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).