From: Martin Schiller <ms@dev.tdt.de>
To: Xie He <xie.he.0141@gmail.com>
Cc: "David S. Miller" <davem@davemloft.net>,
Jakub Kicinski <kuba@kernel.org>,
Jonathan Corbet <corbet@lwn.net>,
Krzysztof Halasa <khc@pm.waw.pl>,
linux-x25@vger.kernel.org, netdev@vger.kernel.org,
linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH net-next RFC] net: x25: Queue received packets in the drivers instead of per-CPU queues
Date: Tue, 09 Mar 2021 14:23:41 +0100 [thread overview]
Message-ID: <4b30ca506b0d79ef5ba1a5e9ce9cf2cd@dev.tdt.de> (raw)
In-Reply-To: <20210305054312.254922-1-xie.he.0141@gmail.com>
On 2021-03-05 06:43, Xie He wrote:
> X.25 Layer 3 (the Packet Layer) expects layer 2 to provide a reliable
> datalink service such that no packets are reordered or dropped. And
> X.25 Layer 2 (the LAPB layer) is indeed designed to provide such
> service.
>
> However, this reliability is not preserved when a driver calls
> "netif_rx"
> to deliver the received packets to layer 3, because "netif_rx" will put
> the packets into per-CPU queues before they are delivered to layer 3.
> If there are multiple CPUs, the order of the packets may not be
> preserved.
> The per-CPU queues may also drop packets if there are too many.
>
> Therefore, we should not call "netif_rx" to let it queue the packets.
> Instead, we should use our own queue that won't reorder or drop
> packets.
>
> This patch changes all X.25 drivers to use their own queues instead of
> calling "netif_rx". The patch also documents this requirement in the
> "x25-iface" documentation.
I've tested the hdlc_x25 driver.
Looks good to me.
Acked-by: Martin Schiller <ms@dev.tdt.de>
next prev parent reply other threads:[~2021-03-09 13:24 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-03-05 5:43 [PATCH net-next RFC] net: x25: Queue received packets in the drivers instead of per-CPU queues Xie He
2021-03-09 13:23 ` Martin Schiller [this message]
2021-03-09 19:31 ` Xie He
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=4b30ca506b0d79ef5ba1a5e9ce9cf2cd@dev.tdt.de \
--to=ms@dev.tdt.de \
--cc=corbet@lwn.net \
--cc=davem@davemloft.net \
--cc=khc@pm.waw.pl \
--cc=kuba@kernel.org \
--cc=linux-doc@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-x25@vger.kernel.org \
--cc=netdev@vger.kernel.org \
--cc=xie.he.0141@gmail.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 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).