Linux RDMA and InfiniBand development
 help / color / mirror / Atom feed
From: Honggang LI <honggangli@163.com>
To: linux-rdma@vger.kernel.org
Subject: Re: Question about extra 40 bytes needed for UD receive buffer
Date: Mon, 15 Apr 2024 18:10:26 +0800	[thread overview]
Message-ID: <Zhz9EkBFTZjzp4Wg@fc39> (raw)
In-Reply-To: <ZhyXEOC9SMIxjXP1@fc39>

On Mon, Apr 15, 2024 at 10:55:12AM +0800, Honggang LI wrote:
> Subject: Question about extra 40 bytes needed for UD receive buffer
> From: Honggang LI <honggangli@163.com>
> Date: Mon, 15 Apr 2024 10:55:12 +0800
> 
> However, I'm confused by the dump of `mckey` receive buffer. The flag
> `IBV_WC_GRH` is set in `ibv_wc.wc_flags`, but there is no GRH in
> the receive buffer. Received data starts from the *first* byte of
> receive buffer. As multicast over UD QP only, can someone please explian
> why there is no GRH in receive buffer and the data starts from the first
> bytes of receive buffer with `IBV_WC_GRH` was set?

Please ignore this. I made a mistake with the offset of the grh.

There is a valid IP header in the receive buffer of 'mckey'.


      reply	other threads:[~2024-04-15 10:10 UTC|newest]

Thread overview: 2+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2024-04-15  2:55 Question about extra 40 bytes needed for UD receive buffer Honggang LI
2024-04-15 10:10 ` Honggang LI [this message]

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=Zhz9EkBFTZjzp4Wg@fc39 \
    --to=honggangli@163.com \
    --cc=linux-rdma@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 a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox