All of lore.kernel.org
 help / color / mirror / Atom feed
From: Cong Wang <xiyou.wangcong@gmail.com>
To: Eric Dumazet <edumazet@google.com>
Cc: Linux Kernel Network Developers <netdev@vger.kernel.org>,
	Saeed Mahameed <saeedm@mellanox.com>
Subject: Re: [Patch net v2] mlx5: fixup checksum for short ethernet frame padding
Date: Wed, 28 Nov 2018 19:40:29 -0800	[thread overview]
Message-ID: <CAM_iQpWbCCSMcqeKVO=VWbvGncnm=A5WjQKi1s6UZZkjY3x81g@mail.gmail.com> (raw)
In-Reply-To: <CANn89iJC6CimzRCTP0gfJMVvh_JVoQ9duXsEMo0MOzoEnU9=1A@mail.gmail.com>

On Wed, Nov 28, 2018 at 4:07 PM Eric Dumazet <edumazet@google.com> wrote:
>
> A NIC is supposed to deliver frames, even the ones that 'seem' bad.

A quick test shows this is not the case for mlx5.

With the trafgen script you gave to me, with tot_len==40, the dest host
could receive all the packets. Changing tot_len to 80, tcpdump could no
longer see any packet. (Both sender and receiver are mlx5.)

So, packets with tot_len > skb->len are clearly dropped before tcpdump
could see it, that is likely by mlx5 hardware.

  reply	other threads:[~2018-11-29 14:44 UTC|newest]

Thread overview: 29+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2018-11-28  6:10 [Patch net v2] mlx5: fixup checksum for short ethernet frame padding Cong Wang
2018-11-28 15:00 ` Eric Dumazet
2018-11-28 22:16   ` Cong Wang
2018-11-28 23:50     ` Eric Dumazet
2018-11-28 23:57       ` Cong Wang
2018-11-29  0:05         ` Cong Wang
2018-11-29  0:14           ` Eric Dumazet
2018-11-30  0:03           ` Saeed Mahameed
2018-11-29  0:07         ` Eric Dumazet
2018-11-29  3:40           ` Cong Wang [this message]
2018-11-29  3:49             ` Eric Dumazet
2018-11-29  3:53               ` Cong Wang
2018-11-29  4:09                 ` Eric Dumazet
2018-11-30  0:30                   ` Saeed Mahameed
2018-12-03 23:17 ` David Miller
2018-12-03 23:45   ` Cong Wang
2018-12-04 19:21   ` Saeed Mahameed
2018-12-04 20:50     ` Cong Wang
2018-12-05  1:06       ` Saeed Mahameed
2018-12-05  2:15         ` Cong Wang
2018-12-13  8:40         ` Nikola Ciprich
2018-12-13 17:08           ` Saeed Mahameed
2018-12-14  9:33             ` Nikola Ciprich
2019-01-05 18:35             ` Nikola Ciprich
2019-01-06 11:10               ` Saeed Mahameed
2019-01-18  1:19                 ` Christoph Paasch
2019-01-19  0:45                   ` Saeed Mahameed
2019-01-22 11:35                     ` David Laight
2018-12-05  2:52 ` Cong Wang

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='CAM_iQpWbCCSMcqeKVO=VWbvGncnm=A5WjQKi1s6UZZkjY3x81g@mail.gmail.com' \
    --to=xiyou.wangcong@gmail.com \
    --cc=edumazet@google.com \
    --cc=netdev@vger.kernel.org \
    --cc=saeedm@mellanox.com \
    /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.